Fuel cell SOFC

ID=711

The Role of Strain in Proton Conduction in Multi-Oriented BaZr0.9Y0.1O3−δ Thin Film

Authors	Muhammad Shahrukh Saleem, Qianli Chen, Nick A. Shepelin, Simone Dolabella, Marta D. Rossell, Xuhai Zhang, Coleman X. Kronawitter, Fabio La Mattina, and Artur Braun
Source	ACS Appl. Mater. Interfaces Volume: 14, Issue: 50, Pages: 55915–55924 Time of Publication: 2022
Abstract	Within the emerging field of proton-conducting fuel cells, BaZr0.9Y0.1O3−δ (BZY10) is an attractive material due to its high conductivity and stability. The fundamentals of conduction in sintered pellets and thin films heterostructures have been explored in several studies; however, the role of crystallographic orientation, grains, and grain boundaries is poorly understood for proton conduction. This article reports proton conduction in a self-assembled multi-oriented BZY10 thin film grown on top of a (110) NdGaO3 substrate. The multiple orientations are composed of different lattices, which provide a platform to study the lattice-dependent conductivity through different orientations in the vicinity of grain boundary between them and the substrate. The crystalline stacking of each orientation is confirmed by X-ray diffraction analysis and scanning transmission electron microscopy. The transport measurements are carried out under different gas atmospheres. The highest conductivity of 3.08 × 10–3 S cm–1 at 400 °C is found under a wet H2 environment together with an increased lattice parameter of 4.208 Å, while under O2 and Ar environments, the film shows lower conductivity and lattice parameter. Our findings not only demonstrate the role of crystal lattice for conduction properties but also illustrate the importance of self-assembled strategies to achieve high proton conduction in BZY10 thin films.
Keywords	BaZrO3 thin film; BaZr0.9Y0.1O3−δ strained structure; proton conduction; crystallographic orientation
Remark	https://doi.org/10.1021/acsami.2c12657 Link

ID=708

A New Electroactive and Stable Electrode Based on Praseodymium Molybdate for Symmetrical SOFCs

Authors	N.V. Lyskov, A.I. Kotova, D.I. Petukhov, S.Ya. Istomin, G.N. Mazo
Source	Russian Journal of Electrochemistry Volume: 58, Pages: 989–997 Time of Publication: 2022
Abstract	The electrochemical activity of a new electrode material based on Pr5Mo3O16 + δ (Ð ÐÐž) within the composition of a symmetrical solid oxide fuel cell (S-SOFC) of the electrolyte-supported design is studied. The model S-SOFC of the Ð ÐÐž/Ce0.9Gd0.1O1.95(GDC)/Zr0.84Y0.16O1.92(YSZ)/GDC/PMO composition demonstrated the maximum power density of 28 mW/cm2 at 900°Ð¡. To improve the power characteristics of S-SOFC, the porous buffer GDC layer is modified by the method of Pr6O11 infiltration. It is found that the addition of electroactive Pr6O11 into the GDC buffer layer provides the three-fold increase in the fuel-cell power density with the maximum of 90 mW/cm2 at 900°Ð¡. The 10 h life-time test of the model S-SOFC with the Ð ÐÐž/GDC + Pr6O11/YSZ/GDC + Pr6O11/PMO composition carried out at a load of 0.7 V reveals the absence of any considerable degradation in fuel cell power characteristics. The results obtained suggest that the new electrode material based on PMO holds promise for the development of S-SOFC.
Remark	Link

ID=703

Development and characterization of highly stable electrode inks for low-temperature ceramic fuel cells

Authors	Sanaz Zarabi Golkhatmi, Muhammad Imran Asghar, Peter D. Lund
Source	Journal of Power Sources Volume: 552, Pages: 232263 Time of Publication: 2022
Abstract	Inkjet printing is a potential contactless and mask-free additive manufacturing approach for solid oxide fuel cells. Here, a highly stable cathode ink using La0.6Sr0.4Co0.2Fe0.8O3 was developed and characterized with particle size analysis, viscosity, surface tension, density, and thermal analysis. Both fresh and 6-months stored inks showed excellent jetability behavior with a Z number of 2.77 and 3.45, respectively. The ink was successfully inkjet-printed on a (LiNaK)2CO3-Gd:CeO2 porous electrolyte substrate to fabricate a symmetric cell. The electrochemical impedance spectroscopy measurements showed that at 550 °C the inkjet printing lowered the ohmic resistance to one-third (from 1.05 Ω cm2 to 0.37 Ω cm2) and the mass diffusion resistance by 4.25 times (from 6.09 Ω cm2 to 1.43 Ω cm2) as compared to drop-casted cell by creating a hierarchical porous structure and increasing reaction sites. Successful inkjet printing of the functional electrode material opens up a new avenue for the fabrication of the low-temperature ceramic fuel cells.
Keywords	Inkjet printing; Ceramics; Electrode; Solid oxide fuel cell; Stability
Remark	https://doi.org/10.1016/j.jpowsour.2022.232263 Link

ID=698

Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures

Authors	Sea-Fue Wang, Yi-Le Liao, Yung-Fu Hsu, Piotr Jasinski
Source	International Journal of Hydrogen Energy Volume: 47, Issue: 94, Pages: 40067-40082 Time of Publication: 2022
Abstract	Three low-temperature solid oxide fuel cells are built using Sm0.2Ce0·8O2-δ (SDC) as the electrolyte. Cell A is symmetrical and features Ni–LiNi0.8Co0·15Al0·05O2 (Ni–NCAL) electrodes, Cell B comprises a Ni–NCAL anode and a Ni–Ag cathode, and Cell C is fabricated using a Ni–NCAL cathode and a Ni–Ag anode. The ohmic resistance and polarization resistance (Rp) of Cells B and C are significantly higher than those of Cell A. The reduction of NCAL at the anodes of Cells A and B yields LiOH and Li2CO3 phases, and the Ni particles generated on the surfaces of the NCAL particles improve the catalytic activity of the cells. Li2CO3–LiOH melts at temperatures >450 °C and penetrates the porous SDC electrolyte layer, causing its densification and abnormal grain growth and increasing its ionic conductivity to >0.2 S/cm at low temperatures. The high open-circuit voltages (OCVs) (0.970–1.113 V) of the cells during electrochemical measurements are ascribed to the Li2CO3–LiOH phase which serves as an electron-blocking layer for the SDC electrolytes. As the reduction of NCAL approaches completion, the anode comprises only Ni phase, which hinders the charge transfer process. The triple-phase-boundary (TPB) area at cathode of Cell B is significantly lower than that of Cell A; therefore, the catalytic activity of Cell B for the oxygen reduction reaction is lower than that of Cell A. Consequently, the maximum power density (MPD) of Cell B is less than half of that of Cell A. The large Rp value of Cell C is ascribed to its low TPB area at Ni–Ag anode which has no reaction with H2 during operation. No visible sintering of the SDC electrolyte layer is observed for Cell C; therefore, its ionic conductivity is considerably smaller than those of the electrolyte layers of Cells A and B. The OCVs of Cell C (0.281–0.495 V) are significantly lower than the typical OCVs of ceria-based SOFCs. This is attributed to the porous SDC electrolyte layer of Cell C. The large Rp values and the low OCVs contribute to the low MPDs of Cell C at various temperatures.
Keywords	Solid oxide fuel cell; NCAL electrode; Polarization; Cell performance
Remark	https://doi.org/10.1016/j.ijhydene.2022.09.148 Link

ID=696

Magnetron sputtered LSC-GDC composite cathode interlayer for intermediate-temperature solid oxide fuel cells

Authors	A.A. Solovyev, A.V. Shipilova, S.V. Rabotkin, E.A. Smolyanskiy, A.N. Shmakov
Source	International Journal of Hydrogen Energy Volume: 47, Issue: 89, Pages: 37967-37977 Time of Publication: 2022
Abstract	The paper investigates the influence of the La0.6Sr0.4CoO3-δ-Gd0.1Ce0.9O1.95 (LSC-GDC) composite cathode interlayer on the operation of solid oxide fuel cells (SOFCs). Thin composite layers with the different GDC content are obtained by the reactive magnetron sputtering. The impact of the high-temperature annealing on the LSC-GDC phase composition is studied by the X-ray diffraction instrument using additionally a synchrotron radiation. The NiO-YSZ anodes with the YSZ electrolyte thin film and GDC barrier layer are used for the SOFC fabrication. The current-voltage curves and impedance spectra of SOFCs are obtained in the temperature range of 700–800°Ð¡. It is shown that not annealed composite layers with ∼50 vol% GDC content possess the most efficient electrochemical activity. The maximum power density of the SOFC with the LSC-GDC interlayer is 1322, 1041 and 796 mW/cm2 at 800, 750 and 700 °C, respectively, which is 20–35% higher than that of the cell without cathode interlayer.
Remark	https://doi.org/10.1016/j.ijhydene.2022.08.281 Link

ID=694

Nanostructured La0.75Sr0.25Cr0.5Mn0.5O3–Ce0.8Sm0.2O2 Heterointerfaces as All-Ceramic Functional Layers for Solid Oxide Fuel Cell Applications

Authors	Juan de Dios Sirvent, Albert Carmona, Laetitia Rapenne, Francesco Chiabrera, Alex Morata, Mónica Burriel, Federico Baiutti, and Albert Tarancon
Source	ACS Appl. Mater. Interfaces Volume: 14, Issue: 37, Pages: 42178–42187 Time of Publication: 2022
Abstract	The use of nanostructured interfaces and advanced functional materials opens up a new playground in the field of solid oxide fuel cells. In this work, we present two all-ceramic thin-film heterostructures based on samarium-doped ceria and lanthanum strontium chromite manganite as promising functional layers for electrode application. The films were fabricated by pulsed laser deposition as bilayers or self-assembled intermixed nanocomposites. The microstructural characterization confirmed the formation of dense, well-differentiated, phases and highlighted the presence of strong cation intermixing in the case of the nanocomposite. The electrochemical propertiesâsolid/gas reactivity and in-plane conductivityâare strongly improved for both heterostructures with respect to the single-phase constituents under anodic conditions (up to fivefold decrease of area-specific resistance and 3 orders of magnitude increase of in-plane conductivity with respect to reference single-phase materials). A remarkable electrochemical activity was also observed for the nanocomposite under an oxidizing atmosphere, with no significant decrease in performance after 400 h of thermal aging. This work shows how the implementation of nanostructuring strategies not only can be used to tune the properties of functional films but also results in a synergistic enhancement of the electrochemical performance, surpassing the parent materials and opening the field for the fabrication of high-performance nanostructured functional layers for application in solid oxide fuel cells and symmetric systems.
Keywords	thin films, hydrogen oxidation reaction, symmetric functional layers, solid oxide cells, nanocomposites
Remark	https://doi.org/10.1021/acsami.2c14044 Link

ID=691

Effects of LiNi0.8Co0.15Al0.05O2 electrodes on the conduction mechanism of Sm0.2Ce0.8O2−δ electrolyte and performance of low-temperature solid oxide fuel cells

Authors	Sea-Fue Wang, Yi-Le Liao, Yung-Fu Hsu, Piotr Jasinski,
Source	Journal of Power Sources Volume: 546, Pages: 231995 Time of Publication: 2022
Abstract	In this study, three low-temperature solid oxide fuel cells are constructed using Ce0.8Sm0.2O2−δ (SDC) as the electrolyte and Ni–LiNi0.8Co0.15Al0.05O2 (Ni–NCAL) and Ni–Ag as the electrodes. Cell A with symmetrical Ni–NCAL electrodes exhibits the best electrochemical performance. During operation, the Ni–NCAL anode is reduced by H2 atmosphere to form LiOH and Li2CO3. The Li2CO3–LiOH melt produced at >450 °C permeates the SDC electrolyte layer, causing its densification and grain growth in addition to the Li+-ion doping of SDC grains. The maximum electrical conductivity of the Li+-ion-doped SDC at 550 °C is at least one order of magnitude smaller than that of the SDC–Li2CO3–LiOH composite electrolyte (0.331 S cm−1). The ohmic and polarization resistances of Cell A at 550 °C are 0.168 and 0.256 Ω cm2, respectively, and its open-circuit voltage is 1.065 V, indicating the presence of dense SDC electrolyte and electron-blocking layers. The maximum power density of the cell at 550 °C is 535.2 mW·cm−2, which is primarily due to the high catalytic activity for the hydrogen oxidation and oxygen reduction reactions at the electrodes and large electrical conductivity of the SDC–Li2CO3–LiOH composite electrolyte at low temperatures.
Remark	https://doi.org/10.1016/j.jpowsour.2022.231995 Link

ID=690

Efficiencies of cobalt- and copper-based coatings applied by different deposition processes for applications in intermediate-temperature solid oxide fuel cells

Authors	M. Tomas, V. Asokan, J. Puranen, J.-E. Svensson, J. Froitzheim
Source	International Journal of Hydrogen Energy Volume: 47, Issue: 76, Pages: 32628-32640 Time of Publication: 2022
Abstract	Solid Oxide Fuel Cells (SOFCs) are electrochemical conversion devices that produce electricity directly by oxidising a fuel. The interconnects between the individual cells need to be coated to limit Cr(VI) evaporation from the steel and to preserve electrical conductivity. Physical Vapour Deposition (PVD)-coated samples with Ce/Co, Ce/Cu, and Ce/MnCu, and Thermal Spray (TS)-coated Mn/Co, Cu and Mn/Cu and AISI 441 steel samples were exposed at 650 °C for up to 1000 h. The PVD Ce/Co and Ce/Cu coatings, as well as the TS Mn/Co coating, exhibited the formation of a thin protective Cr2O3 scales underneath the coating. These samples also exhibited the lowest area-specific resistance (ASR) values. The remainder of the samples exhibited much higher mass gains and higher ASR values. Cr(VI) evaporation measurements showed that all the coatings behaved approximately the same despite the PVD coatings being only about one-tenth of the thickness of the TS coatings.
Remark	https://doi.org/10.1016/j.ijhydene.2022.07.168 Link

ID=672

On the mechanism of Mn(II)-doping in Scandia stabilized zirconia electrolytes

Authors	Einar Vøllestad, Vegar Øygarden, Joachim Seland Graff, Martin Fleissner Sunding, John D. Pietras, Jonathan M. Polfus, Marie-Laure Fontaine
Source	Acta Materialia Volume: 227, Pages: 117695 Time of Publication: 2022
Abstract	Cubic Scandia-stabilized zirconia (ScSZ) is an attractive electrolyte material for solid oxide cells due to its significant ionic conductivity, provided that the phase transition to its rhombohedral polymorph upon cooling is suppressed. The latter is achieved with addition of a secondary co-dopant, albeit it may be at the detriment of its ionic conductivity Here, we thoroughly investigate how MnO2 (0.5–10 mol%) as a co-dopant impacts on the sinterability, thermal expansion, crystal structure and ionic conductivity of ZrO2 doped with 10 mol% Scandia (10ScSZ), and we provide new insight on the chemistry of dissolved manganese in the fluorite lattice. Reactive sintering of 2 mol% MnO2 mixed with 10ScSZ enables to produce dense electrolyte with significant reduction of the peak sintering temperature and stabilisation of the cubic structure down to room temperature. Combined density functional theory and X-ray photoelectron spectroscopy analyses reveal that manganese predominantly enters the structure as Mn2+ during reactive sintering, with a prevalence of higher valence states at the surface and grain boundaries. The highest oxide ion conductivity is achieved for 2 mol% doped 10ScSZ (120 mScm−1 at 800 °C) and it decreases with increasing Mn concentration. For all compositions, the bulk conductivity remains independent of pO2 – corroborating a limited electronic conductivity contribution from Mn-doping. The grain boundary conductivity is found to decrease with sintering time and pO2, which is attributed to the chemistry and concentration of segregated manganese at the surface and grain boundaries, yielding depletion of oxygen vacancies in the space charge layer.
Keywords	Electrical conductivity; SOFC; Reactive sintering; ScSZ; Stability
Remark	https://doi.org/10.1016/j.actamat.2022.117695 Link

ID=669

Impedance spectroscopy study of Au electrodes on Gd-doped CeO2 (GDC) – Molten Li2CO3+Na2CO3 (LNC) composite electrolytes

Authors	Vijayan Sobhana Dilimon, Ragnar Strandbakke, Truls Norby
Source	Journal of Power Sources Volume: 522, Pages: 230986 Time of Publication: 2022
Abstract	We herein report an impedance spectroscopy study of Au electrodes on Gd-doped CeO2 (GDC) – molten Li2CO3+Na2CO3 (LNC) composite electrolytes in O2 and O2+CO2 atmospheres. Complementary measurements of Au on GDC alone are provided for supporting insight. We find that the adsorption of CO2 on GDC in O2+CO2 atmospheres effectively blocks oxygen adsorption and severely slows oxygen reduction kinetics. The conductivity of the composite is dominated by the GDC phase in the solid-solid temperature region, while the LNC phase dominates above its melting point, and no further enhancement e.g. by interfacial effects are found. The incorporation of LNC melt into GDC results in a significant reduction in the polarisation resistance of Au electrodes in O2 atmospheres, as the melt mediates the reaction by a peroxide mechanism. In O2+CO2 atmospheres, however, the polarisation resistance of Au electrodes on GDC-LNC membranes is significantly higher, higher even than that on GDC. This we assign again to the blocking adsorption of CO2 (or carbonate) on the surfaces of ceria and the sluggish transport and reactions now mediated by carbonate-carried oxide species (CO42−) instead of peroxide species.
Keywords	Molten carbonate fuel cells; MCFC; CeO2; Gd-doped; GDC; GDC-Molten carbonate composite electrolyte; Oxygen electrode; Mechanism
Remark	Link

ID=666

Advanced metal oxide infiltrated electrodes for boosting the performance of solid oxide cells

Authors	Alodia Orera, Alejandro Betato, Jorge Silva-Trevino, Angel Larrea and Miguel A. Laguna-Bercero
Source	J. Mater. Chem. A Time of Publication: 2021
Abstract	An efficient way for boosting the performance of solid oxide electrodes is the infiltration of metallic nanoparticles into both electrodes. In this work we will focus on improving the performance of standard lanthanum strontium manganite oxygen electrodes, by the addition of different metal oxide nanoparticles. First studies will be performed using cerium oxide nanoparticles, as this is the classic oxide already proposed in the literature. Other novel metal oxides such as praseodymium or manganese oxide will be explored, as studies in the literature for these two metal oxides are very scarce. The effect of metal oxide infiltration into LSM/YSZ oxygen electrodes will be studied in both symmetrical cells and complete microtubular cells using conventional fuel electrodes (NiO-YSZ) and electrolytes (YSZ). The obtained current densities in both fuel cell and electrolysis modes are significantly enhanced in comparison with other results in the literature for microtubular configuration.
Remark	DOI: 10.1039/D1TA07902F Link

ID=664

High-performance anode-supported solid oxide fuel cells with co-fired Sm0.2Ce0.8O2-δ/La0.8Sr0.2Ga0.8Mg0.2O3−δ/Sm0.2Ce0.8O2-δ sandwiched electrolyte

Authors	Sea-Fue Wang, Hsi-Chuan Lu, Yung-Fu Hsu, Piotr Jasinski
Source	International Journal of Hydrogen Energy Volume: 47, Issue: 8, Pages: 5429-5438 Time of Publication: 2022
Abstract	In this study, intermediate-temperature solid oxide fuel cells (IT-SOFCs) with a nine-layer structure are constructed via a simple method based on the cost-effective tape casting-screen printing-co-firing process with the structure composed of a NiO-based four-layer anode, a Sm0.2Ce0·8O2-δ(SDC)/La0·8Sr0.2Ga0.8Mg0·2O3−δ (LSGM)/SDC tri-layer electrolyte, and an La0·6Sr0·4Co0·2Fe0·8O3-δ (LSCF)-based bi-layer cathode. The resultant SDC (4.14 μm)/LSGM (1.47 μm)/SDC (4.14 μm) tri-layer electrolyte exhibits good continuity and a highly dense structure. The Ro and Rp values of the single cell are observed to be 0.15 and 0.08 Ω cm2 at 800 °C, respectively, and the MPD of the cell is 1.08 Wcm-2. The high MPD of the cell appears to be associate with the significantly lower area-specific resistance and the reasonably high OCV. Compared to those with a similar electrolyte thickness reported in prior studies, the nine-layer anode-supported IT-SOFC with a tri-layer electrolyte developed by the study demonstrates superior cell properties.
Remark	Link

ID=663

Synthesis, structure and ionic conductivity of nanocrystalline Ce1−xLaxO2−δ as an electrolyte for intermediate temperature solid oxide fuel cells

Authors	Naeemakhtar Momin, J. Manjanna, Lawrence D’Souza, S.T. Aruna, S.Senthil Kumar
Source	Journal of Alloys and Compounds Volume: 896, Pages: 163012 Time of Publication: 2022
Abstract	La-doped CeO2 nanoparticles of composition Ce1−xLaxO2−δ (0 ≤ x ≤ 0.1) have been studied here as prospective electrolytes for intermediate temperature solid oxide fuel cells (IT-SOFCs). They were synthesized by auto-combustion method and the powder samples were calcined at 700 °C to get ultrafine nanocrystalline particles. They were characterized by XRD, Raman, FTIR, XPS, DRS, FESEM/EDX, particle size analyzer and ac-impedance techniques. Ionic conductivity was measured from 350 − 750 °C. The Ce0.90La0.1O2−δ (0.1 LDC) and Ce0.95La0.05O2−δ (0.05 LDC) showed a maximum conductivity of 8.89 × 10−3 and 8.32 × 10−3 S cm−1 at 700 °C, respectively. The σt of 0.1 LDC = 1.01 × 10−2 S cm−1 at 750 °C. The activation energy of 0.1 LDC and 0.05 LDC was found to be 0.70 eV and 0.87 eV, respectively. These values are higher than those reported for La-doped CeO2 in literature. The SOFC performance with 0.05 LDC as electrolyte showed open circuit voltage of 0.81 V and maximum power density of 41 mW cm−2 at 650 °C using hydrogen as fuel.
Remark	Link

ID=662

Unlocking bulk and surface oxygen transport properties of mixed oxide-ion and electron conducting membranes with combined oxygen permeation cell and oxygen probe method

Authors	Yongliang Zhang, Kevin Huang
Source	Journal of Membrane Science Volume: 644, Pages: 120082 Time of Publication: 2022
Abstract	Surface exchange kinetics and bulk diffusion of oxygen are of paramount importance to the activity of oxygen electrocatalysis and performance of electrochemical devices such as fuel cell, metal-air batteries, and oxygen separation membranes. Conventional approaches to obtaining these transport properties are often limited to single property under a specific non-operation related condition. Here we use a combined oxygen permeation cell and oxygen probe methodology to simultaneously attain rates of oxygen surface exchange and bulk conductivity/chemical diffusivity of three representative mixed oxide-ion and electron conductors, namely SrCo0.9Ta0.1O3-δ (SCT), La0.6Sr0.4CoO3-δ (LSC) and La0.6Sr0.4FeO3-δ (LSF), operated under a steady-state oxygen flux. The results explicitly show that SCT exhibit the highest oxide-ion conductivity/chemical diffusivity, fastest rates of surface oxygen exchange kinetics, thus promising to be the best oxygen electrocatalyst. We have also mapped out the distribution of oxygen chemical potential gradient across the membranes and applied B-transport number concept to illustrate the rate-limiting steps in the overall oxygen permeation process.
Remark	Link

ID=658

Electrochemical Performance of SrWO4 Electrolyte for SOFC

Authors	Ahmed Afif, Nikdalila Radenahmad, Juliana Zaini, Abdalla Mohamed Abdalla, Seikh Mohammad Habibur Rahman, Quentin Hoon Nam Cheok, Abul Kalam Azad
Source	The International Journal of Integrated Engineering Volume: 13, Issue: 1, Pages: 74-80 Time of Publication: 2021
Abstract	cheelite structured SrWO4 material was synthesized by the solid-state sintering method and studied with respect to phase stability and ionic conductivity under condition of technological relevance for SOFC applications. The resulting compound was crystallized in the single phase of tetragonal scheelite structure with the space group of I41/a. Room temperature X-ray diffraction and subsequent Rietveld analysis confirms its symmetry, space group and structural parameters. Analysis by SEM illustrated a highly dense structure. SrWO4 sample shows lower conductivity compared to the raditional BCZY perovskite structured materials. SrWO4 sample exhibited an ionic conductivity of 1.93 × 10−6 S cm-¹ at 1000°C in dry Ar condition. Since this scheelite type compound demonstrated significant conductivity and a dense microstructure, it could serve in SOFC as a mixed ion-conducting electrolyte.
Remark	Link

ID=652

Anode-supported solid oxide fuel cells with multilayer LSC/CGO/LSC cathode

Authors	A.A. Solovyev, K.A. Kuterbekov, S.A. Nurkenov, A.S. Nygymanova, A.V. Shipilova, E.A. Smolyanskiy, S.V. Rabotkin., I.V. Ionov
Source	Fuel Cells Volume: 21, Issue: 4, Pages: 408-412 Time of Publication: 2021
Abstract	The multilayer La0.6Sr0.4CoO3/Ce0.9Gd0.1O2/La0.6Sr0.4CoO3 (LSC/CGO/LSC) thin film cathode of the solid oxide fuel cell (SOFC) with the different thickness of the LSC and CGO layers are obtained by magnetron sputtering. Cathodes are deposited onto the NiO/8YSZ anode-supported 8YSZ/CGO bilayer electrolyte. The influence of the deposited multilayer cathode on the SOFC performance is investigated in the temperature range between 800 and 600°C. It is shown that the thin-film multilayer cathode allows increasing the SOFC efficiency, and the obtained optimum thickness of the LSC and CGO layers provides the maximum power density for SOFCs. The maximum power density of 2430, 1170, and 290 mW cm–2 is obtained respectively at 800, 700, and 600°C for the SOFCs with the LSC/CGO/LSC layer 50/50/50 nm thick. The polarization resistance measured at 800 and 750°C on the symmetric SOFC with the CGO electrolyte and LSC/CGO/LSC cathode is 0.17 and 0.3 Ω cm2, respectively.
Remark	Link

ID=645

Structural and Electrochemical Properties of Scandia Alumina Stabilized Zirconia Thin Films

Authors	Mantas Sriubas, Darius Virbukas, Nursultan Kainbayev, Kristina Bockute and Giedrius Laukaitis
Source	Coatings Volume: 11, Issue: 7, Pages: 800 Time of Publication: 2021
Abstract	This work presents a systematic investigation of scandia alumina stabilized zirconia (ScAlSZ, composition: ZrO2:Sc2O3:Al2O3 93:6:1 wt.%) thin films (~2 μm). Thin films were formed by the e-beam evaporation method on 450 °C substrates. The influence of Al concentration on thin film microstructure, structure, and electrochemical properties was characterized by EDS, XRD, Raman, and EIS methods. It was found that the aluminum concentration in the deposited thin films decreased with an increase in the deposition rate. The concentration of Al changed from 15.9 to 3.8 at.% when the deposition rates were 0.2 and 1.6 nm/s, respectively. The crystallinity of the thin films depended strongly on the concentration of Al, resulting in an amorphous phase when Al concentration was 22.2 at.% and a crystalline phase when Al concentration was lower. ScAlSZ thin films containing 15.9 at.% of Al had monoclinic and tetragonal phases, while thin films with 1.6 and 3.8 at.% of Al had a mixture of cubic, tetragonal, and monoclinic phases. The phase transition was observed during the thermal annealing process. Cubic and rhombohedral phases formed in addition to monoclinic and tetragonal phases appeared after annealing ScAlSZ thin films containing 15.9 and 22.2 at.% of aluminum. The highest total ionic conductivity (σbulk = 2.89 Sm−1 at 800 °C) was achieved for ScAlSZ thin films containing 3.8 at.% of Al. However, thin films containing a higher concentration of aluminum had more than 10 times lower total conductivity and demonstrated changes in activation energy at high temperatures (>560 °C). Activation energies changed from ~1.10 to ~1.85 eV.
Keywords	electron beam deposition; scandia alumina stabilized zirconia (ScAlSZ); solid oxide fuel cells (SOFC); ionic conductivity
Remark	https://doi.org/10.3390/coatings11070800 Link

ID=643

Preparation of NdBaCo2O5+δ–Ce0.9Gd0.1O1.95 composite cathode by in situ sol-mixing method and its high-temperature electrochemical properties

Authors	Sun Liping, Li Na, Li Qiang, Huo Lihua, Zhao Hui
Source	Journal of Alloys and Compounds Volume: 885, Pages: 160901 Time of Publication: 2021
Abstract	NdBaCo2O5+δ-xCe0.9Gd0.1O1.95 (NBCO-xCGO, x = 0 ~ 8 wt%) composite materials are prepared by novel sol-mixing method and evaluated as cathodes for intermediate-temperature solid oxide fuel cells. The chemical compatibility, thermal expansion behavior and electrochemical performance of NBCO-xCGO composite cathodes are studied. There is no chemical reaction between NBCO and CGO after sintering at 1100 °C for 12 h. Introducing CGO leads to the decrease of both thermal expansion coefficient and conductivity. Among all the composites, NBCO-5CGO shows the lowest polarization resistance of 0.034 Ω cm2 at 700 °C. The anode-supported single-cell with NBCO-5CGO cathode exhibits a maximum power density of 1.0 W cm−2 at 700 °C. The electrochemical impedance spectrum measurement combining with the distribution of relaxation times analysis proves that the addition of CGO nanoparticles significantly improves the surface oxygen dissociation process, and the charge transfer process is identified to be the reaction limiting step to control the oxygen reduction kinetics on NBCO-5CGO composite cathode.
Keywords	Intermediate-temperature solid oxide fuel cell; Composite cathode; Distribution of relaxation times analysis; Oxygen reduction kinetics
Remark	https://doi.org/10.1016/j.jallcom.2021.160901 Link

ID=632

Microstructure and electrochemical behavior of layered cathodes for molten carbonate fuel cell

Authors	K.Cwieka, A. Lysik, T. Wejrzanowski, T. Norby, W. Xing
Source	Journal of Power Sources Volume: 500, Pages: 229949 Time of Publication: 2021
Abstract	In the present paper, we demonstrate how modifications of the microstructure and the chemical composition can influence the electrochemical behavior of cathodes for molten carbonate fuel cells (MCFCs). Based on our experience, we designed new MCFC cathode microstructures combining layers made of porous silver, nickel oxide or nickel foam to overcome common issues with the internal resistance of the cell. The microstructures of the standard NiO cathode and manufactured cathodes were extensively investigated using scanning electron microscopy (SEM) and porosity measurements. The electrochemical behavior and overall cell performance were examined by means of electrochemical impedance spectroscopy and single-cell tests in operation conditions. The results show that a porous silver layer tape cast onto standard NiO cathode and nickel foam used as a support layer for tape cast NiO porous layer substantially decrease resistance components representing charge transfer and mass transport phenomena, respectively. Therefore, it is beneficial to combine them into a three-layer cathode since it facilitates separation of predominant physio-chemical processes of gas and ions transport in respective layers ensuring high efficiency. The superiority of the three-layer cathode has been proven by low impedance and high power density as compared to standard NiO cathode.
Remark	Link

ID=630

Preparation and characterization of (La,Ca,Sr)(Fe,Co)O3-d cathodes for solid oxide fuel cells

Author	Mario Karl Micu-Budisteanu
Source	Time of Publication: 2021
Remark	Master Thesis Link

ID=626

The Effect of Thin Functional Electrode Layers on Characteristics of Intermediate Temperature Solid Oxide Fuel Cell

Authors	A. V. Shipilova, A. A. Solov’ev, E. A. Smolyanskii, S. V. Rabotkin & I. V. Ionov
Source	Russian Journal of Electrochemistry Volume: 57, Pages: 97–103 Time of Publication: 2021
Abstract	The thin-film multilayer structure of the membrane-electrode assembly in a solid oxide fuel cell which involves a NiO/ZrO2:Y2O3 anode functional layer and a La0.6Sr0.4CoO3 cathode functional layer and also a bilayer ZrO2:Y2O3/Ce0.9Gd0.1O1.95 electrolyte is formed by magnetron sputtering onto a supporting NiO/ZrO2:Y2O3 anode. The effect of the functional electrode layers involved in the structure of a solid oxide fuel cell on its efficiency is studied. The volt–ampere characteristics of multilayer fuel cells are studied in the temperature range of 800–600°C. It is shown that the inclusion of a thin (600 nm thick) cathode functional layer into the structure of the membrane–electrode assembly enhances the fuel cell efficiency by reducing the polarization losses on electrodes. The maximum power density of the fuel cell with the cathode functional layer is 2290 and 500 mW/cm2 at 800 and 600°Ð¡, respectively. The simultaneous presence of anode and cathode functional layers is found to be unwelcome because gives rise to diffusion limitations on the anode.
Remark	Link

ID=621

Fused filament fabrication for anode supported SOFC development: Towards advanced, scalable and cost-competitive energetic systems

Authors	C. Bergesa, A. Wain, R. Andújar, J. A. Naranjo, A. Gallego, E. Nieto, G. Herranz, R. Campana
Source	International Journal of Hydrogen Energy Volume: 46, Issue: 51, Pages: 26174-26184 Time of Publication: 2021
Remark	Link

ID=617

The performance of intermediate temperature solid oxide fuel cells with sputter deposited La1-xSrxCoO3 interlayer

Authors	A. A. Solovyev, A. V. Shipilova, I. V. Ionov, E. A. Smolyanskiy, A. V. Nikonov & N. B. Pavzderin
Source	Journal of Electroceramics Volume: 45, Pages: 156–163 Time of Publication: 2020
Abstract	The paper studies the performance of the intermediate temperature solid oxide fuel cells with the sputter deposited La1-xSrxCoO3 (LSC) interlayer between the cathode and electrolyte. The sputter deposition of the LSC thin films is carried out in argon gas and in a mixture of argon and oxygen gases and then are annealed at 600, 800 and 1000 °C in air for 2 h. The structure and composition of the sputter deposited LSC films are investigated by the X-ray diffraction analysis, scanning and transmission electron microscopies, and energy-dispersive X-ray spectroscopy. The polarization resistance of the sputter deposited LSC films (600 nm thick) on the symmetric cells is 0.13, 0.45 and 2.48 Ohm·cm2 measured at 800, 700 and 600 °C, respectively. Measurements are performed by electrochemical impedance spectroscopy. The maximum power density of the anode-supported solid oxide fuel cells with the yttria-stabilized zirconia/gadolinia-doped ceria bilayer electrolyte, LSC interlayer, and LSC cathode is 2.27, 1.58 and 0.68 W/cm2 measured at 800, 700 and 600 °C, respectively. These values of the power density are respectively 1.4, 1.6 and 2.3 times higher than that of the reference cell without the LSC interlayer.
Remark	Link

ID=610

Comparative investigation on the functional properties of alkaline earth metal (Ca, Ba, Sr) doped Nd2NiO4+δ oxygen electrode material for SOFC applications

Authors	R. K. Lenka, P.K.Patro, Vivek Patel, L. Muhmood, T. Mahata
Source	Journal of Alloys and Compounds Volume: 860, Pages: 158490 Time of Publication: 2021
Abstract	Functional properties of Nd2NiO4+δ based materials doped with different alkaline earth metal ions for SOFC applications is studied extensively and compared in this article. Phase pure powders of Nd2NiO4 +δ and Nd1.7A0.3NiO4+δ (A=Ca, Sr and Ba) were synthesized by solid state route at 1250 °C from the constituent precursor oxides and carbonates. Good compatibility of these cathode materials with GDC electrolyte is confirmed through XRD analysis of the composite powder heat treated at 1250 °C. Electrical conductivity of undoped Nd2NiO4+δ is found to attain a maximum at ~470 °C and then decreases noticeably with increase in temperature. The decrease in conductivity at higher temperatures is not significant for alkaline earth metal ion doped systems. In the lower temperature range, electrical conductivity decreases with alkaline earth metal ion doping and this decrement is more as the size of the dopant cation increases with an exception for Sr doped samples. However, at the operating temperature of the fuel cell (say 800 °C) electrical conductivity of Ca and Sr doped Nd2NiO4+δ are higher than the undoped material. Polarization resistance of the cathode materials are evaluated from the measured impedance spectra of symmetric cells and activation energy for oxygen reduction reaction is calculated from the Arrhenius plot of polarization resistance. Activation energy decreases with alkaline earth metal ion doping and this decrease is more in case of Ca doping followed by Sr and Ba doping. Electrolyte supported button cells fabricated under identical processing conditions were tested at 800 °C; highest power density of 188 mW cm−2 is obtained for the cell having Ca doped Nd2NiO4+δ as oxygen electrode.
Keywords	SOFC; Air electrode; Nd2NiO4; Area specific resistance; I-V characteristics
Remark	https://doi.org/10.1016/j.jallcom.2020.158490 Link

ID=609

Synthesis and processing of SOFC components for the fabrication and characterization of anode supported cells

Authors	Aritza Wain-Martin, Roberto Campana, Aroa Morán-Ruiz, Aitor Larrañaga, María Isabel Arriortua
Source	Boletín de la Sociedad Española de Cerámica y Vidrio Time of Publication: 2020
Abstract	In this article, it is intended to evaluate the performances of previously synthesized different nanometric compounds as SOFC components under real conditions. For this purpose, anodic supports SOFCs have been manufactured in different configurations. The compounds NiO-(Y2O3)0.08(ZrO2)0.92 (NiO–YSZ), (Y2O3)0.08(ZrO2)0.92 (YSZ), Sm0.2Ce0.8O1.9 (SDC), La0.6Sr0.4FeO3 (LSF) and LaNi0.6Fe0.4O3 (LNF) were used as anode support, electrolyte, barrier, cathode and contact layer, respectively. To obtain the cells, the anode supports were produced by uniaxial pressing and the remaining layers were added using the airbrush technique, assembling them by different sintering processes. The cells developed have been electrochemically tested in a temperature range between 750 and 865 °C. Additionally, degradation tests have been carried out under constant current. Moreover, to characterize the microstructure of the cells, a scanning electron microscope (SEM) equipped with an energy dispersive X-ray spectroscopy (EDX) analyzer has been used. The results obtained show that the incorporation of cathode and contact layers increases the power densities and decreases the total resistances of the cells with respect to the cell without cathode, especially with the addition of the LNF contact layer. Despite the improvement obtained, more tests have to be carried out in order to optimize the performance of SOFC devices in degradation tests.
Keywords	Solid oxide fuel cells; Processing; Composite; Degradations; Electrochemical impedance spectra
Remark	Available online 22 December 2020 Link

ID=608

Increasing the thermal expansion of proton conducting Y-doped BaZrO3 by Sr and Ce substitution

Authors	Amir Masoud Dayaghi, Reidar Haugsrud, Marit Stange, Yngve Larring, Ragnar Strandbakke, Truls Norby
Source	Solid State Ionics Volume: 359, Pages: 115534 Time of Publication: 2021
Abstract	Proton conducting oxide electrolytes find potential application in proton ceramic fuel cells and electrolyzers operating at intermediate temperatures, e.g. 400–600 °C. However, state-of-the-art proton conducting ceramics based on Y-doped BaZrO3 (BZY) have lower thermal expansion coefficient (TEC) than most commonly applied or conceived supporting electrode structures, making the assembly vulnerable to degradation due to cracks or spallation. We have increased the TEC of 20 mol% Y-doped BZY (BZY20) by partially substituting Ba and Zr with Sr and Ce, respectively, to levels which still maintain the cubic structure and sufficiently minor n-type conduction; (Ba0.85Sr0.15)(Zr0.7Ce0.1Y0.2)O2.9 (BSZCY151020). High temperature XRD shows that this material has a cubic structure (space group ) in the temperature range of 25–1150 °C and a linear TEC of ~10 × 10−6 K−1, as compared to the ~8 × 10−6 K−1 for BZY. It exhibited a DC conductivity of ~5 mS cm−1 at 600 °C in wet H2. This electrolyte with increased TEC may find application in proton ceramic electrochemical cells in general and metal supported ones in particular.
Keywords	Barium zirconate; BZY; Thermal expansion coefficient; TEC; Conductivity; Proton; Proton ceramic electrochemical cells; Metal-supported
Remark	https://doi.org/10.1016/j.ssi.2020.115534 Link

ID=606

Reversible fuel electrode supported solid oxide cells fabricated by aqueous multilayered tape casting

Authors	L. Bernadet, M. Morales, X. G. Capdevila, F. Ramos, M. C. Monterde, J. A. Calero, A. Morata, M. Torrell and A. Tarancón
Source	J. Phys. Energy Volume: 3, Issue: 2, Pages: 024002 Time of Publication: 2021
Abstract	Fuel electrode supported solid oxide cells (SOCs) have been developed on an industrial scale using the aqueous tape-casting technique. The NiO–yttria-stabilized zirconia Y2O3–ZrO2 (YSZ) fuel electrode and YSZ electrolyte have been manufactured by multilayer co-laminated tape casting. Details of the tape-casting slurry formulations are described and discussed. Two types of cells were fabricated with different microstructures of the NiO–YSZ support discussed. Good electrochemical performance and stability in SOFC mode at 750 °C and 0.7 V for both button cells reaching around >0.75 W cm−2 and with no measurable degradation after >700 h were observed. The selected cell was scaled up to large-area cells (36 cm2 of the active area) and electrochemically tested at 750 °C in a single repetition unit (SRU) in SOFC (Solid Oxide Fuel Cell), SOEC (Solid Oxide Electrolysis Cell) and co-SOEC (Solid Oxide co-Electrolysis Cell) mode, and in a short-stack of two SRUs in SOFC mode. A current up to 17 A was obtained at 1.4 V (0.7 V cell−1) with the short-stack configuration in SOFC mode, corresponding to ∼0.5 A cm−2 and 24 W. The performances of the aqueous-based SOC cells can be considered highly remarkable, thus supporting the success in scaling the fabrication of SOC stacks using more environmentally friendly processes than conventional ones.
Remark	Link

ID=596

Strategies to Mitigate the Degradation of Stainless-SteelInterconnects Used in Solid Oxide Fuel Cells

Author	Claudia GÐŸbel
Source	Time of Publication: 2020
Abstract	Interconnects are a vital part of solid oxide fuel cells (SOFC), where they electricallyconnect individual cells to form a fuel cell stack. They are a main contributor to theoverall stack cost and the limited life-time of fuel cells, and, therefore, improvementscarried out on the interconnect level could further the commercialization of SOFCs.The limited life-time of the interconnect is related to the material used today, ferriticstainless steels (FSS). FSS interconnects are more cost-effective than previously usedceramics, but they degrade under the conditions prevalent in an SOFC: high temperaturesbetween 600°C and 850°C, and a p(O2) gradient. Certain corrosion phenomena thatoccur, such as Cr evaporation and continuous oxide scale growth, negatively impact cellperformance due to cathode poisoning and increased electrical resistance, respectively.These phenomena have been found to be effectively mitigated by coatings, such as the(Co,Mn)3O4(MCO) coating, or reactive element coatings, such as Ce.The present thesis examines these coatings with regard to three aspects: (i) doesthe semi-conducting spinel coating affect the electrical resistance of the interconnectnegatively, or is its conductivity negligible in comparison to the continuously growingCr2O3scale below it; (ii) does the coating self-heal if it is cracked even at intermediatetemperatures, i.e. 650°C and 750°C, or do the cracks persist and increase Cr evaporation;and (iii) is the long-term stability of the state-of-the-art Ce/Co coating (10 nm Ce/640 nmCo) still effective after 35 000 h, or not. The second aspect is not only important tounderstand corrosion behavior, but it would also allow for large-scale roll-to-roll PVDcoating, which is significantly more cost-effective than batch coating.Another corrosion phenomenon that is elucidated within the scope of this work is thedual atmosphere effect. This effect leads to increased corrosion on the air-facing side ofthe interconnect if the FSS is exposed to a dual atmosphere, i.e. air on one side andhydrogen on the other side, compared to if the FSS is exposed to an air-only atmosphere.A new theory as to why the dual atmosphere effect occurs is proposed, and it is indirectlyverified by means of excluding all other possibilities. Factors that influence the dualatmosphere effect are discussed, and it is shown how the dual atmosphere effect could, inpart, be mitigated.
Keywords	Solid Oxide Fuel Cell; Corrosion; Interconnect; Cr Evaporation; Area SpecificResistance; Deformation; Long-term; Dual Atmosphere; Hydrogen
Remark	THESIS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY Link

ID=593

Crystal structures and proton transport properties of Sr2(Ti1-xMx)O4-δ (M = Fe, Al)

Authors	Yutaro Yagi, Isao Kagomiya, Ken-ichi Kakimoto
Source	Solid State Sciences Volume: 108, Pages: 106407 Time of Publication: 2020
Abstract	This study focuses on the effects of acceptor dopants in proton-conductive Sr2TiO4-based layered perovskites. We synthesized Sr2Ti0.9Fe0.1O4-δ (STF10) and Sr2Ti0.95Al0.05O4-δ (STA05) and evaluated the influence of ion substitution on their crystal structures, electrical conductivities, and proton transport properties. Our obtained results suggest that a redox reaction is the more favorable mechanism for the introduction of proton defects to Fe-doped samples compared with water vapor absorption, while the reverse is true for Al-doped samples. STF10 was found to exhibit a larger electrical conductivity at low temperatures than STA05. In addition, STF10 presented a proton transport number of 0.5 at 600 °C, while the corresponding value for STA05 was 0.5–0.6 at 450–600 °C. The higher proton transport number of STA05 at 450–550 °C compared to that of STF10 indicates that the Al-dopant suppressed the electronic conductivity owing to its constant valency. We therefore considered that characterization of the changes in material properties related to ion substitution can serve as a guide for material selection when developing proton-conducting solid oxide fuel cell technologies.
Remark	Link

ID=584

Structural characterization and electrical/electrochemical studies of Nd1-xBaxCo1-y(Fe, Ti)y O3-δ (0 ≤ x ≤ 0.3, y = 0, 0.2) materials as cathode for SOFCs application

Authors	Paramananda Jena, Dinesh Kumar, Pankaj Kumar Patro, Raja Kishora Lenka, Akhilesh Kumar Singh
Source	Journal of Solid State Chemistry Volume: 292, Pages: 121682 Time of Publication: 2020
Abstract	Perovskite oxide powders of Nd1-xBaxCo1-y (Fe, Ti)y O3-δ (0 ≤ x â≤ â0.3, y â= â0, 0.2) were synthesized by combustion technique and investigated as cathode materials for SOFCs application. The Rietveld refinement of the XRD data confirms the formation of single phase orthorhombic perovskite structure of Pbnm space group within the compositions (0 â≤ âx â≤ â0.1, y â= â0, 0.2). The microstructural studies revealed the grains generated are irregular in shape and non uniform in size in the micrometer range. The X-ray photoelectron spectroscopy (XPS) analysis confirms the presence of mixed valence states of Co3+/Co4+, Fe3+/Fe4+, Ti4+/Ti3+ and O-Lattice/O-Chemisorbed/O-physisorbed species. The measured average CTE values are varies from 18–25 â× â10−6 âK−1 in the temperature range 200–900 â°C for all the synthesized samples. The electrical conductivity values are found to be 252 Scm−1, 308 Scm−1, 157 Scm−1 at 700 â°C for the compositions Nd0.9Ba0·1CoO3-δ (NBC 0.1), Nd0.9Ba0·1Co0·8Fe0·2O3-δ (NBCFO), Nd0.9Ba0·1Co0·8Ti0·2O3-δ (NBCTO), respectively. XRD analysis reveals no chemical reactivity for the compositions NBCFO, NBCTO with 20 âmol% gadolinium doped ceria oxide (Ce0.8Gd0.2O2−δ) electrolyte material after firing at 1200 â°C for 8 âh. The area specific resistances (ASR) were calculated for the symmetrical cells and are found to be 0.67 âΩ âcm2, 1.07 âΩ âcm2 at 850 â°C for the NBCFO, NBCTO compositions, respectively. Among the compositions evaluated Nd0.9Ba0·1Co0·8Fe0·2O3-δ showed highest total electrical conductivity ~308 Scm−1 and lowest ASR value ~0.67 Ωcm2 compared to all other compositions. Hence the result suggests the synthesized Nd0.9Ba0·1Co0·8Fe0·2O3-δ composition could be a promising cathode material for SOFCs application.
Remark	Link

ID=583

Effect of the Complexing Agent in the Pechini Method on the Structural and Electrical Properties of an Ionic Conductor of Formula La1−xSrxAlO3−δ (x = 0, 0.05, 0.1, 0.15)

Authors	F. Hadji, F. Bouremmad, S. ShawutiM. A. Gulgun
Source	Advances in Renewable Hydrogen and Other Sustainable Energy Carriers Pages: 387-393 Time of Publication: 2020
Abstract	The Ion conductors are used as electrolytes in high temperature Solid Oxide Fuel Cells SOFCs. The preparation route has an important role on their structural and electrical properties. In this study, we used a modified Pechini method to prepare an ionic conductor based on lanthanum aluminate doped with strontium La1−xSrxAlO3−δ (x = 0.0.05, 0.1, 0.15). The effect of two complexing agents on structural and electrical properties was studied, we used Ethylene Diamine Tetra Acetic EDTA, and tartaric acid TA as complexing agents. The perovskite phases were obtained at 900 °C and characterized by different techniques; SEM images show that grain size is in the nanometer range, XRD analysis shows that the compounds prepared by use of the two complexing agents crystallize in a perovskite structure with an orthorhombic system and an R3m space group, the doped phases prepared by EDTA have a secondary phase LaSrAl3O7 which is absent in the compounds prepared by tartaric acid. The determination of the ionic conductivity by electrochemical impedance spectroscopy shows clearly the effect of the complexing agent. Indeed we have found that the value of the ionic conductivity is higher for the phases produced by the Pichini method in the presence of tartaric acid as complexing agent.
Remark	Link

ID=578

In-situ Ni exsolution from NiTiO3 as potential anode for solid oxide fuel cells

Authors	Lucía M.Toscani, Florencia Volpe Giangiordano, Nora Nichio, Francisco Pompeo, Susana A. Larrondo
Source	International Journal of Hydrogen Energy Volume: 45, Issue: 43 Time of Publication: 2020
Abstract	Sample NiTiO3 (NTO) is prepared by the molten salts synthesis route as a potential anode material for solid oxide fuel cell (SOFC) applications. An additional sample impregnated with 5 mol%Ni (N-NTO) is also presented. Structural characterization reveal a pure NiTiO3 phase upon calcination at 850 °C and 1000 °C. Redox characterization by temperature programmed reduction tests indicate the transition from NiTiO3 to Ni/TiO2 at ca. 700 °C. Ni nanoparticles (ca. 26 nm) are exsolved in-situ from the structure after a reducing treatment at 850 °C. Catalytic activity tests for partial oxidation of methane performed in a fixed bed reactor reveal excellent values of activity and selectivity due to the highly dispersed Ni nanoparticles in the support surface. Time-on-stream behavior during 100 h operation in reaction conditions for sample N-NTO yield a stable CH4 conversion. Electrolyte supported symmetrical cells are prepared with both materials achieving excellent polarization resistance of 0.023 Ω cm2 in 7%H2/N2 atmosphere at 750 °C with sample N-NTO. The maximum power density achieved is of 273 mW cm−2 at 800 °C with a commercial Pt ink used as a reference cathode, indicating further improvement of the system can be achieved and positioning the N-NTO material as a promising SOFC anode material.
Remark	Link

ID=568

Studying the Effects of Siloxanes on Solid Oxide Fuel Cell Performance

Authors	Zivak, Milica
Source	Time of Publication: 2020
Abstract	Solid oxide fuel cells (SOFCs) are a promising technology for converting landfill gas into electricity, simultaneously providing a renewable source of energy. However, the contaminants present in landfill gas pose an obstacle to using it for energy generation. The research objective was to examine the effect siloxanes in landfill gas have on the performance of Ni-YSZ/Hionic™/LSM SOFCs, particularly through silica deposition on the Ni-YSZ anode. This was accomplished with voltammetric experiments using the ProboStat™ and anode surface analysis using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). To establish whether siloxanes can be detrimental to SOFC operation, hydrogen spiked with varying concentrations of decamethylcyclopentasiloxane (D5), a representative siloxane, was used as a fuel gas. Compared to operation under pure H2, which reliably gives a steady state output, the cell showed a 10% loss in voltage after 3 hours each at 1 ppmv D5 and 5 ppmv D5. Another cell operated on H2 gas containing 10 ppmv D5 experienced a 13% loss in voltage output after 6 hours, and SEM/EDS analysis showed the presence of silica deposits on the cell anodes. This was viewed as water generated via electrochemical reaction hydrolyzing siloxanes to silica and poisoning the SOFC anode. However, when humidified methane, a better landfill gas analogue, was spiked with D5, the cell’s voltage output was stable, and silica was not detected on the anode; instead D5 was deposited as silica on surfaces inside the ProboStat™. Thus, the necessity of humidifying the hydrocarbon fuel also provided a protection against anode poisoning by siloxanes. Nevertheless, experiments with humidified Mahoning Landfill gas failed to reach the expected voltage and current output. It was not clear from SEM/EDS analysis what contaminants were responsible for the decreased cell performance; more surface-sensitive techniques are recommended for further studies.
Remark	Master of Science in Chemistry, Youngstown State University, Department of Chemistry. Link

ID=567

High ionic conductivity dysprosium and tantalum Co-doped bismuth oxide electrolyte for low-temperature SOFCs

Authors	P. S. Cardenas-Terrazas, M. T. Ayala-Ayala, J. Muñoz-Saldaña, A. F. Fuentes, D. A. Leal-Chavez, J. E. Ledezma-Sillas, C. Carreño-Gallardo & J. M. Herrera-Ramirez
Source	Ionics Volume: 26, Pages: 4579–4586 Time of Publication: 2020
Abstract	A novel double dysprosium- and tantalum-doped bismuth oxide electrolyte synthesized by solid-state reaction for low-temperature solid oxide fuel cells (LT-SOFCs) is here reported. The phase structures at room temperature were defined by X-ray powder diffraction (XRD). A stable δ-Bi2O3 phase was obtained by co-doping Bi2O3 with Dy2O3 and Ta2O5 in specific contents. The effect of the co-dopant total content (5–15 mol%) on the ionic conductivity was measured as a function of temperature (300 to 700 °C). Results revealed that the (Dy2O3)13(Ta2O5)2(Bi2O3)85 system showed the highest ionic conductivity as 0.08 S cm−1 at 500 °C, which is three times higher than the binary system reported in the literature (E2O3)20(Bi2O3)80 (20ESB) and in the same range as the ternary system with the highest conductivity reported so far (Dy2O3)8(W2O3)4(Bi2O3)88 (8D4WSB). The lowest activation energy for our system was 0.20 eV at temperatures higher than 550 °C.
Remark	Link

ID=551

A CO2-Tolerant Perovskite Oxide with High Oxide Ion and Electronic Conductivity

Authors
Source	Adv. Mater. Time of Publication: 2019
Abstract	Mixed ionic–electronic conductors (MIECs) that display high oxide ion con-ductivity (σo) and electronic conductivity (σe) constitute an important family of electrocatalysts for a variety of applications including fuel cells and oxygen sepa-ration membranes. Often MIECs exhibit sufficient σe but inadequate σo. It has been a long-standing challenge to develop MIECs with both high σo and stability under device operation conditions. For example, the well-known perovskite oxide Ba0.5Sr0.5Co0.8Fe0.2O3−δ (BSCF) exhibits exceptional σo and electrocatalytic activity. The reactivity of BSCF with CO2, however, limits its use in practical applications. Here, the perovskite oxide Bi0.15Sr0.85Co0.8Fe0.2O3−δ (BiSCF) is shown to exhibit not only exceptional bulk transport properties, with a σo among the highest for known MIECs, but also high CO2 tolerance. When used as an oxygen separation membrane, BiSCF displays high oxygen permeability comparable to that of BSCF and much higher stability under CO2. The combination of high oxide transport properties and CO2 tolerance in a single-phase MIEC gives BiSCF a significant advantage over existing MIECs for practical applications.
Remark	DOI: 10.1002/adma.201905200 Link

ID=549

Long-term (4 year) degradation behavior of coated stainless steel 441 used for solid oxide fuel cell interconnect applications

Authors
Source	Journal of Power Sources Time of Publication: 2019
Abstract	The present work aims to investigate the long-term stability of Ce/Co coated AISI 441 used as an interconnect material in solid oxide fuel cells (SOFC). Being a commercially available alloy the use of AISI 441 would greatly reduce the cost of SOFCs in comparison to tailor-made interconnect materials such as Crofer 22 APU. To analyze the long-term stability Ce/Co coated AISI 441 is exposed in air at 800 °C for up to 38 000 h. Mass gain values are recorded continuously. After 7 000, 23 000, and 35 000 h area specific resistance (ASR) measurements are performed, and cross-sections are prepared and analyzed using scanning electron microscopy (SEM) and energy dispersive x-ray (EDX) spectroscopy. Cr-evaporation measurements are conducted on samples exposed for up to 38 000 h.
Keywords	SOFC, Interconnect, Corrosion, Ce/Co coating, AISI 441, Long-term
Remark	https://doi.org/10.1016/j.jpowsour.2019.227480 Link

ID=545

Intriguing electrochemistry in low-temperature single layer ceramic fuel cells based on CuFe2O4

Authors
Source	International Journal of Hydrogen Energy Time of Publication: 2019
Abstract	A composite of CuFe2O4 and Gd-Sm co-doped CeO2 is studied for a single layer ceramic fuel cell application. In order to optimize the cell performance, the effects of sintering temperatures (600 °C, 700 °C, 800 °C, 900 °C and 1000 °C) were investigated for the fabrication of the cells. It was found that the cells sintered at 700 °C outperformed other cells with a maximum peak power density of 344 mW/cm2 at 550 °C. The electrochemical impedance spectroscopy analysis on the best cell revealed significant ohmic losses (0.399 Ω cm2) and polarization losses (0.174 Ω cm2) in the cell. The HR-TEM and SEM gave microstructural information of the cell. The HT-XRD spectra showed the crystal structures in different sintering temperatures. The cell performance was stable and the composite material did not degrade during an 8 h stability test under open-circuit condition. This study opens up new avenues for the exploration of this nanocomposite material for the low temperature single component ceramic fuel cell research.
Keywords	Catalysis; Ceramic; Composite; Fuel cell; Single component
Remark	https://doi.org/10.1016/j.ijhydene.2019.09.175 Link

ID=544

Mn-rich SmBaCo0.5Mn1.5O5+δ double perovskite cathode material for SOFCs

Authors	Anna Olszewska, Yang Zhang, Zhihong Du, Mateusz Marzec, Konrad Świerczek, Hailei Zhao, Bogdan Dabrowski
Source	International Journal of Hydrogen Energy Volume: 44, Issue: 50 Time of Publication: 2019
Abstract	SmBaCo0.5Mn1.5O5+δ oxide with Sm-Ba cation-ordered perovskite-type structure is synthesized and examined in relation to whole RBaCo0.5Mn1.5O5+δ series (R: selected rare earth elements). Presence of Sm and 3:1 ratio of Mn to Co allows to balance physicochemical properties of the composition, with moderate thermal expansion coefficient value of 18.70(1)·10−6 K−1 in 300–900 °C range, high concentration of disordered oxygen vacancies in 600–900 °C range (δ = 0.16 at 900 °C), and good transport properties with electrical conductivity reaching 33 S cm−1 at 900 °C in air. Consequently, the compound enables to manufacture catalytically-active cathode, with good electrochemical performance measured for the electrolyte-supported laboratory-scale solid oxide fuel cell with Ni-Gd1.9Ce0.1O2-δ\|La0.4Ce0.6O2-δ\|La0.8Sr0.2Ga0.8Mg0.2O3-δ\|SmBaCo0.5Mn1.5O5+δ configuration, for which 1060 mW cm−2 power density is observed at 900 °C. Furthermore, the tested symmetrical SmBaCo0.5Mn1.5O5+δ\|La0.8Sr0.2Ga0.8Mg0.2O3-δ\|SmBaCo0.5Mn1.5O5+δ cell delivers 377 mW cm−2 power density at 850 °C, which is a promising result.
Keywords	Mn-rich layered perovskites; Physicochemical properties; Cathode materials; SOFC; Symmetrical SOFC
Remark	https://doi.org/10.1016/j.ijhydene.2019.08.254 Link

ID=539

Microstructural and compositional optimization of La0.5Ba0.5CoO3−δ — BaZr1−zYzO3−δ (z=0,0.05 and 0.1) nanocomposite cathodes for protonic ceramic fuel cells

Authors	Laura Rioja-Monllor, Carlos Bernuy-Lopez, Marie-Laure Fontaine,Tor Grande and Mari-Ann Einarsrud
Source	J. Phys.: Energy Volume: 2 Time of Publication: 2019
Abstract	Cathodes are one of the key components of protonic ceramic fuel cells (PCFCs) requiring further development to enhance the performance of PCFCs. This encompasses the optimization of material compositions and microstructures, as well as a further understanding of the electrode processes. Here, a compositional optimization of a La0.5Ba0.5CoO3−δ —BaZrO3-based nano-composite cathode prepared by exsolution of a single-phase material was performed by substituting 5 and 10 mol% Y at the B-site in the BaZrO3 phase. Electrodes with different microstructures were prepared by two different deposition methods, spray coating and screen printing, and by varying the firing temperature from 600°C to 1100 °C. Further, composite electrodes were prepared by directly coating and firing the single-phase materials on the dense electrolyte to prepare symmetric cells. A good adhesion of the cathode to the electrolyte was observed in all cases. In general, a more homogeneous microstructure was observed for the cathodes prepared by screen printing. The single step method encompassing exsolution of the single phase and firing of the symmetric cells yielded significant improvement in the cathode performance compared to the other routes. The best electrochemical performance was observed for La0.5Ba0.5CoO3−δ —BaZr0.9Y0.1O2.95 cathode with an area specific resistance of 4.02 Ω cm2 at 400 °C and 0.21 Ω cm2 at 600 °C in 3% moist synthetic air. These results are among the best reported for cathodes of PCFCs as will be discussed.
Keywords	protonic ceramic fuel cells, cathode, exsolution, composites
Remark	https://doi.org/10.1088/2515-7655/ab396c Link

ID=537

Fabrication and encapsulation of micro-SOFCs

Author	Andrea Turchi
Source	Time of Publication: 2019
Remark	Tesi di Laurea Magistrale Link

ID=534

Synthesis and Study of (Sr,La)2FeCo0.5Mo0.5O6 − δ Oxides with Double Perovskite Structure

Authors	M. M. Abdullaev, S.Ya. Istomin, A.V. Sobolev, I.A. Presnyakov, E.V. Antipov
Source	Russian Journal of Inorganic Chemistry Volume: 64, Issue: 6, Pages: 696–704 Time of Publication: 2019
Abstract	Complex oxides Sr2 − xLaxFeCo0.5Mo0.5O6 − δ, (x = 0.2, 0.4; δ ≈ 0.03–0.15) have been first synthesized by the sol-gel method. Their crystal structures have been refined by the Rietveld method; the refinement showed that the complex oxides have the structure of cubic double perovskite (a ≈ 2aper, space group Fm3̄m) with partial ordering of Fe(Co) and Mo in the B positions. Based on the 57Fe Mössbauer measurements, the average formal oxidation state of iron has been found to decrease from +3.20 (x = 0.0) to +3.04 (x = 0.4). Our study of the behavior of perovskites in a reducing Ar/H2 atmosphere (8%) revealed a decrease in the reduction resistance with decreasing La content (x = 0.4 → 0). The combination of the properties studied, namely chemical stability with respect to the reaction with Ce1 − xGdxO2 − x/2 and Zr1 − xYxO2 − x/2, high-temperature thermal expansion, and electrical conductivity in air and Ar/H2, shows that Sr1.6La0.4Fe-Co0.5Mo0.5O6 − δ (δ ≈ 0.03) perovskite is more attractive as an electrode material for medium-temperature symmetric solid oxide fuel cells than Sr2FeCo0.5Mo0.5O6 − δ.
Remark	Link

ID=532

Influence of Lanthanum Doping on Structural and Electrical/Electrochemical Properties of Double Perovskite Sr2CoMoO6 as Anode Materials for Intermediate-Temperature Solid Oxide Fuel Cells

Authors	Pravin Kumar, Paramananda Jena, P. K. Patro, R. K. Lenka, A. S. K. Sinha, Prabhakar Singh, Rajendra Kumar Singh
Source	ACS Appl. Mater. Interfaces Volume: 11, Issue: 27, Pages: 24659-24667 Time of Publication: 2019
Abstract	Lanthanum (La3+)-doped double perovskites Sr2CoMoO6 (Sr2–xLaxCoMoO6, 0.00 ≤ x ≤ 0.03) were synthesized via the citrate–nitrate autocombustion route. The Reitveld refinement analysis of X-ray diffraction reveals the tetragonal symmetry as the main phase with space group I4/m and also confirms the presence of some peaks corresponding to extra phase SrMoO4. The SEM micrograph images reflect that grains are in irregular shape and sizes for all samples. Average grain size gradually decreases with the increase of the SrMoO4 phase. The X-ray photoelectron spectroscopy (XPS) analysis confirms the presence of mixed valence states of Mo5+/Mo6+, Co2+/Co3+, and O-lattice/O-chemisorbed/O-physisorbed species. Coefficient of thermal expansion (CTE) analysis shows that the particular composition Sr1.97La0.03CoMoO6 has the lowest CTE value among the compositions studied. The electrical conductivity of Sr2CoMoO6 is enhanced effectively by doping La at Sr sites. The measured area-specific resistance (ASR) for the composition Sr1.97La0.03CoMoO6 (SLCM03) is found to be appreciably low, ∼0.053 Ohm cm–2 at 800 °C. The obtained highest electrical conductivity with the lowest activation energy and low ASR value for the composition Sr1.97La0.03CoMoO6 encompasses it as a promising candidate for anode material in the intermediate-temperature solid oxide fuel cell (IT-SOFC) application.
Remark	Link

ID=531

Scheelite type Sr1−xBaxWO4 (x = 0.1, 0.2, 0.3) for possible application in Solid Oxide Fuel Cell electrolytes

Authors	Ahmed Afif, Juliana Zaini, Seikh Mohammad Habibur Rahman, Sten Eriksson, Md Aminul Islam & Abul Kalam Azad
Source	Scientific Reports Volume: 9 Time of Publication: 2019
Abstract	Polycrystalline scheelite type Sr1−xBaxWO4 (x = 0.1, 0.2 & 0.3) materials were synthesized by the solid state sintering method and studied with respect to phase stability and ionic conductivity under condition of technological relevance for SOFC applications. All compounds crystallized in the single phase of tetragonal scheelite structure with the space group of I41/a. Room temperature X-ray diffraction and subsequent Rietveld analysis confirms its symmetry, space group and structural parameters. SEM illustrates the highly dense compounds. Significant mass change was observed to prove the proton uptake at higher temperature by TG-DSC. All compound shows lower conductivity compared to the traditional BCZY perovskite structured materials. SBW with x = 0.3 exhibit the highest ionic conductivity among all compounds under wet argon condition which is 1.9 × 10−6 S cm−1 at 1000 °C. Since this scheelite type compounds show significant conductivity, the new series of SBW could serve in IT-SOFC as proton conducting electrolyte.
Remark	Article number: 9173 (2019) Link

ID=526

Inkjet Printing Functionalization of SOFC LSCF Cathodes

Authors	Eleonora Venezia, Massimo Viviani, Sabrina Presto, Vasant Kumar and Rumen I. Tomov
Source	Nanomaterials Time of Publication: 2019
Abstract	An important segment of the future renewable energy economy is the implementation of novel energy generation systems. Such electrochemical systems are solid oxide fuel cells, which have the advantage of direct conversion of the chemical energy stored in the fuel to electrical energy with high effciency. Improving the performance and lowering the cost of solid oxide fuel cells (SOFCs) are strongly dependent on finding commercially viable methods for nano-functionalization of their electrodes via infiltration. Inkjet printing technology was proven to be a feasible method providing scalability and high-resolution ink delivery. LaxSr1-xCoyFe1-yO3 cathodes were modified using inkjet printing for infiltration with two different materials: Gd-doped ceria (CGO) commonly used as ion-conductor and La0.6Sr0.4CoO3 (LCO) commonly used as a mixed ionic electronic conductor. As-modified surface structures promoted the extension of the three-phase boundary (TPB) and enhanced the mechanisms of the oxygen reduction reaction. Electrochemical impedance measurements revealed significantly lowered polarization resistances (between 2.7 and 3.7 times) and maximum power output enhancement of 24% for CGO infiltrated electrodes and 40% for LCO infiltrated electrodes.
Remark	Link

ID=522

Processing of high performance composite cathodes for protonic ceramic fuel cells by exsolution

Authors	Laura Rioja-Monllor, Carlos Bernuy-Lopez, Marie-Laure Fontaine, Tor Grandea and Mari-Ann Einarsrud
Source	J. Mater. Chem. A Volume: 7, Pages: 8609-8619 Time of Publication: 2019
Abstract	La0.5Ba0.5CoO3−δ–BaZrO3 (LB–BZ)-based composite materials were prepared by a modified Pechini sol–gel method combined with exsolution. Two different LB–BZ composites were prepared through two alternative thermal treatments of the precursor gel. A metastable single phase with a perovskite crystal structure was first obtained upon annealing the precursor in an inert atmosphere, and it was further transformed into a two-phase composite by in situ exsolution in air. Comparatively, direct calcination of the LB–BZ gel in air resulted in a two-phase composite with different microstructures and compositions of the two phases. The composite cathode formed by exsolution consisted of a matrix of BZ-phase with ∼45 nm grain size embedding ∼20 nm grains of LB-phase, while the composite cathode obtained by direct calcination consisted of a mixture of both phases with 50–60 nm grain size. Electrodes of symmetric half-cells were spray-coated on the BaZr0.9Y0.1O2.95 electrolyte to examine the electrochemical performance by impedance spectroscopy. The lowest area specific resistance (ASR) was obtained for the composite cathode produced by exsolution with an excellent ASR of 1.54 Ω cm2 at 600 °C and 18 Ω cm2 at 400 °C and an activation energy (Ea) of 0.60 eV in 3% moist synthetic air. This work demonstrates the potential of fabricating high performance nanocomposite cathodes with tailored chemical composition by a novel exsolution method.
Remark	DOI: 10.1039/C8TA10950H Link

ID=521

Optimization of laser-patterned YSZ-LSM composite cathode-electrolyte interfaces for solid oxide fuel cells

Authors	J. A. Cebollero, M. A. Laguna-Bercero, R. Lahoz, J. Silva, R. Moreno, A. Larrea
Source	Journal of the European Ceramic Society Volume: 39, Issue: 12, Pages: 3466-3474 Time of Publication: 2019
Abstract	Patterned cathode/electrolyte interfaces formed by a hexagonal array of ∼22 μm deep wells with 24 μm lattice parameter have been prepared by pulsed laser machining to enlarge the contact surface and, consequently, to reduce the cathode polarization of Solid Oxide Fuel Cells. These new interfaces have been tested in YSZ-LSM/YSZ/YSZ-LSM symmetrical cells, where the cathode is deposited by dip-coating. Appropriate ceramic suspensions have been formulated to penetrate into deep wells without presenting interfacial delamination after sintering. We analyse their applicability by comparing their rheology with the microstructure and electrochemical performance of the cells. The activation component of the polarization resistance is reduced by ∼50% using ethanol-based suspensions with 20 wt% solids loading, although the gas diffusion component increases due to excessive densification. Alternative ceramic suspensions with 17.5 wt% solids loading provide optimum electrode gas diffusion but lower activation components, resulting in an overall decrease of ∼20% in polarization resistance.
Remark	https://doi.org/10.1016/j.jeurceramsoc.2019.02.049 Link

ID=519

SOFC cathodic layers using wet powder spraying technique with self synthesized nanopowders

Authors
Source	International Journal of Hydrogen Energy Volume: 44, Issue: 14, Pages: 7555-7563 Time of Publication: 2019
Abstract	In this work, a wet powder spraying method has been investigated as a facile low cost route to deposit electrode layer on SOFC electrolyte support. A particular focus has been examining the interfacial stability of the deposited layers, and determining the influence of the thickness of the different layers, as well as the ball milling regime used to produce the electrode inks. The developed system consist of an yttria stabilized zirconia electrolyte support, a La0.6Sr0.4FeO3 (LSF) cathode, a Sm0.2Ce0.8O1.9 (SDC) barrier layer between the electrolyte and the cathode, and LaNi0.6Fe0.4O3 (LNF) as a contact layer, for a future integration with the SOFC interconnector. The electrolyte supports (300 μm thickness and 9 mm diameter) supports were prepared by uniaxial pressing, while the deposition of thin barrier layers, cathode and contact layer were carried out by manual spray coating.
Remark	https://doi.org/10.1016/j.ijhydene.2019.01.220 Link

ID=512

Versatile Application of Redox Processes for REBaCoMnO5+δ (RE: La, Pr, Nd, Sm, Gd, and Y) Oxides

Authors	Anna Olszewska, Konrad Świerczek, Wojciech Skubida, Zhihong Du, Hailei Zhao, Bogdan Dabrowski
Source	J. Phys. Chem. C Volume: 123, Issue: 1, Pages: 48-61 Time of Publication: 2019
Abstract	Belonging to the not fully explored REBaCo2-xMnxO5+δ system, a series of REBaCoMnO5+δ (RE: selected rare earth elements) oxides having perovskite-type structure is synthesized and studied in terms of their structural properties, oxygen content, stability, thermal expansion, and transport properties. Impact of RE3+ on physicochemical properties of the compounds is derived, with smaller cations causing a decrease of the unit cell volume, lowering of the total oxygen content and thermal expansion, but also suppressing electrical conductivity. It is shown that a proper chemical modification enables to successfully utilize REBaCoMnO5+δ in applications, in which redox processes associated with oxygen reduction/oxidation and transport determine the effectiveness of the working material. In particular, NdBaCoMnO5+δ (with larger Nd3+) shows good chemical stability in relation to Ce0.8Gd0.2O2−δ and La0.8Sr0.2Ga0.8Mg0.2O3-δ solid electrolytes and moderate thermal expansion, 20.04(4)·10–6 K–1 in 300–900 °C. In symmetrical configuration with La0.8Sr0.2Ga0.8Mg0.2O3-δ electrolyte its cathodic polarization resistance is found to be only 0.036 Ω cm2 at 900 °C, making it an excellent candidate cathode for solid oxide fuel cells. At the same time, YBaCoMnO5+δ (with small and cheap Y3+) delivers reversible oxygen storage capacity surpassing 3.4 wt % during the oxygen partial pressure swing process between air and 5 vol % H2 in Ar at 500 °C.
Remark	Link

ID=510

Effect of magnetron sputtered anode functional layer on the anode-supported solid oxide fuel cell performance

Authors	A.A. Solovyeva, A.M. Lebedynskiy, A.V. Shipilova, I.V. Ionov, E.A. Smolyanskiy, A.L. Lauk, G.E. Remnev
Source	International Journal of Hydrogen Energy Time of Publication: 2018
Abstract	Nickel oxide-yttria stabilized zirconia (NiO-YSZ) thin films were reactively sputter-deposited by pulsed direct current magnetron sputtering from the Ni and ZrY targets onto heated commercial NiO-YSZ substrates. The microstructure and composition of the deposited films were investigated with regard to application as thin anode functional layers (AFLs) for solid oxide fuel cells (SOFCs). The pore size, microstructure and phase composition of both as-deposited and annealed at 1200 °C for 2 h AFLs were studied by scanning electron microscopy and X-ray diffractometry and controlled by changing the deposition process parameters. The results show that annealing in air at 1200 °C is required to improve structural homogeneity of the films. NiO-YSZ films have pores and grains of several hundred nanometers in size after reduction in hydrogen. Adhesion of deposited films was evaluated by scratch test. Anode-supported solid oxide fuel cells with the magnetron sputtered anode functional layer, YSZ electrolyte and La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathode were fabricated and tested. Influence of thin anode functional layer on performance of anode-supported SOFCs was studied. It was shown that electrochemical properties of the single fuel cells depend on the NiO volume content in the NiO-YSZ anode functional layer. Microstructural changes of NiO-YSZ layers after nickel reduction-oxidation (redox) cycling were studied. After nine redox cycles at 750 °C in partial oxidation conditions, the cell with the anode NiO-YSZ layer showed stable open circuit voltage values with the power density decrease by 11% only.
Remark	In Press, https://doi.org/10.1016/j.ijhydene.2018.11.193 Link

ID=502

Effects of calcium doping to oxygen reduction activity on Pr2-xCaxNiMnO6 cathode

Authors	Liping Sun, Huan Li, Jiaqi Zhao, Guiling Wang, Lihua Huo, Hui Zhao
Source	Journal of Alloys and Compounds Volume: 777, Pages: 1319-1326 Time of Publication: 2019
Abstract	Pr2-xCaxNiMnO6-δ (PCNMOx, x = 0.0–0.3) are prepared successfully by glycine-nitrate method. The effects of calcium doping to the crystal structure, the oxygen non-stoichiometry, and the cathode properties are evaluated by XRD, SEM, XPS and EIS. The double perovskite PCNMOx crystallize into a monoclinic structure with space group P21/n. The unit cell volumes and thermal expansion coefficients increase systematically with Ca2+ doping, due to the gradual generation of oxygen vacancies in the lattice. Pr2-xCaxNiMnO6-δ exhibits promising chemical compatibility with the electrolyte material Ce0.9Gd0.1O1.95 (GDC) at 1200 °C. The electrochemical characterization results indicate that both oxygen vacancy concentration and electrical conductivity play important roles to cathode properties. The optimum composition Pr1.8Ca0.2NiMnO6-δ shows the lowest polarization resistance of 0.18 Ω cm2 and highest peak power density of 0.3 W cm2 at 700 °C on GDC electrolyte supported fuel cell. The electrochemical impedance measurements under oxygen partial pressures, together with distribution of relaxation times analysis, identify three conjunctive elementary processes involved in the cathode reaction, and prove that the charge transfer process is the major rate-determining step of oxygen reduction reaction.
Remark	Link

ID=500

Effect of B-site doping on electrical conductivity of YAlO3 based electrolytes for solid oxide fuel cells

Authors	Ramya Hariharan, Prakash Gopalan
Source	Journal of Electroceramics Volume: 42, Issue: 1-2, Pages: 79–86 Time of Publication: 2019
Abstract	Solid oxide fuel cells (SOFCs) have emerged as high temperature fuel cell technology operating at temperatures around 1000 °C. Lowering the operating temperature enables the use of cheaper materials while maintaining high power outputs. Electrolytes with ABO3-type perovskite structure are good ionic conductors and are promising materials for SOFCs. In this study, a systematic investigation on the synthesis and characterization of Mg- substituted YAlO3 system has been performed. The samples have been synthesized by wet chemical citrate gel route and the electrical conductivity measurements have been conducted in air between 300 and 800 °C. Effect of composition of the phases on total conductivity has been analyzed employing X-ray diffraction. The influence of microstructure on total conductivity has been studied using scanning electron microscopy and orientation imaging microscopy.
Keywords	Intermediate temperature SOFCs, Perovskites, Total conductivity, Citrate gel route, Doping
Remark	Link

ID=496

Dy doped SrTiO3: A promising anodic material in solid oxide fuel cells

Authors	Saurabh Singh, Prabhakar Singh, Massimo Viviani, Sabrina Presto
Source	International Journal of Hydrogen Energy Volume: 43, Issue: 41, Pages: 19242-19249 Time of Publication: 2018
Abstract	The perovskite-type oxides, having a general formula ABO3, are promising candidates for anode materials in solid oxide fuel cells. In particular, doped SrTiO3 based perovskites are potential mixed ionic-electronic conductors and they are known to have excellent thermal and chemical stability along with carbon and sulfur tolerance. In this work, DyxSr1-xTiO3-δ system with x = 0.03, 0.05, 0.08 and 0.10 is studied to understand the influence of Dy content on its structural and electrical behavior. Electrochemical properties are measured, both in air and hydrogen atmosphere, and structural characterizations are performed before and after electrochemical tests and compared each other to study the stability. Results show that DyxSr1-xTiO3-δ powders with x ≤ 0.05, are single phase, while for x ≥ 0.08 a small amount of secondary phases is formed. In air, the conductivity is predominantly mixed ionic-electronic type for x ≤ 0.05, becoming ionic for x ≥ 0.08. It is observed that conductivity, for each composition, increases passing from air to hydrogen and activation energy decreases. Dy0.05Sr0.95TiO3-δ shows the highest conductivity in air whereas Dy0.08Sr0.92TiO3-δ in H2 atmosphere. Degradation observed by XRD is negligible for x ≤ 0.05 but increases with higher Dy content.
Remark	https://doi.org/10.1016/j.ijhydene.2018.08.160 Link

ID=490

Wide bandgap oxides for low-temperature single-layered nanocomposite fuel cell

Authors
Source	Nano Energy Volume: 53, Pages: 391-397 Time of Publication: 2018
Abstract	A composite of wide bandgap lithium-nickel-zinc-oxide (LNZ) and gadolinium-doped-cerium-oxide (GDC) was systematically analyzed for a low-temperature nanocomposite fuel cell in a so-called single-component configuration in which the electrodes and electrolyte form a homogenous mixture. We found that the operational principle of a single-layer fuel cell can be explained by electronic blocking by the oxide mixture with almost insulator-like properties in the operating voltage regime of the fuel cell, which will prevent short-circuiting, and by its catalytic properties that drive the fuel cell HOR and ORR reactions. The resistance to charge transport and leakage currents are dominant performance limiting factors of the single-component fuel cell. A test cell with Au as current collector reached a power density of 357 mWcm−2 at 550 °C. Changing the current collector to a Ni0.8Co0.15Al0.05LiO2 (NCAL) coated Ni foam produced 801 mWcm−2, explained by better catalytic properties. However, utilizing NCAL coated Ni foam may actually turn the 1-layer fuel cell device into a traditional 3-layer (anode-electrolyte-cathode) structure. This work will help in improving the understanding of the underlying mechanisms of a single-layer fuel cell device important to further develop this potential energy technology.
Keywords	Bandgap; Ceramic; Fuel cell; Ionic conductivity; Nanocomposite; Single-component
Remark	https://doi.org/10.1016/j.nanoen.2018.08.070 Link

ID=487

An operando calorimeter for high temperature electrochemical cells

Authors	David Young, Ariel Jackson, David Fork, Seid Sadat, Daniel Rettenwander, Jesse D. Benck, Yet - Ming Chiang
Source	Time of Publication: 2018
Abstract	Operando calorimetry has previously been utilized to study degradation, side reactions, and other electrochemical effects in electrochemical cells such as batteries at or near room temperature. Calorimetric data can provide important information on the lifetime and thermal properties of electrochemical cells and can be used in practical engineering applications such as thermal anagement. High temperature electrochemical cells such as solid oxide fuel cells or electrolyzers can also benefit from operando calorimetry, although to our knowledge no such unit has been eveloped commercially. Herein, we report an operando calorimeter capable of simultaneous calorimetry and electrochemistry at temperatures up to 1,000 °C and in both oxidizing and reducing atmospheres. The calorimeter is constructed by modifying a commercial apparatus originally designed to study high temperature electrochemical cells in various gas environments. We utilize a grey - box, nonlinear system identification model to analyze calorimetric data and achieve an electrochemical cell power sensitivity of 16.1±11.7 mW. This operando calorimeter provides the tools needed to study both the thermal and kinetic behavior of electrochemical cells at elevated temperatures.
Remark	Link

ID=485

A novel anode for solid oxide fuel cells prepared from phase conversion of La0.3Sr0.7Fe0.7Cr0.3O3-δ perovskite under humid hydrogen

Authors	Min Chen, Yang Hu, Dongchu Chen, Huawen Hu, Qing Xu
Source	Electrochimica Acta Volume: 284, Pages: 303-313 Time of Publication: 2018
Abstract	A novel anode for solid oxide fuel cells (SOFCs), consisting of a Ruddlesden-Popper compound, La0.6Sr1.4Fe0.4Cr0.6O3.8, with in situ exsolved α-Fe nanoparticles (RP-LSF + Fe), is prepared from the phase conversion of the La0.3Sr0.7Fe0.7Cr0.3O3-δ (LSFCr-3) perovskite under humid H2 at 800 °C. On the surface of the RP-LSF + Fe anode, Fe cations are presented to be a mixture of Fe2+ and Fe3+, of which the average valence is lower than that in the bulk (Fe3+). The coverage of atomic hydrogen on the RP-LSF + Fe anode is over 0.8 in the pH2 range of 0.017–0.27 atm, implying a significant effect of these small amount (∼8 mol% on the surface) of exsolved Fe nanoparticles (∼200–300 nm) on promoting the dissociative absorption of H2. The charge transfer resistance is found to be closely related to the concentration of surface oxygen vacancies of the oxide matrix. The addition of catalytic amount of Ni (1–3 wt.%) greatly improves the fuel flexibility of the RP-LSF + Fe anode. Furthermore, it contributes to acceleration the phase conversion of the LSFCr-3 perovskite and reduced time for in situ preparation of the RP-LSF + Fe anode. The RP-LSF + Fe anode with 2.7 wt.% Ni exhibits a stable cell performance under 2.7%H2O+1:1-(H2:CO) and 2.7%H2O + CH4 for ∼30 h. It costs shortest time (30 h) to reach a stable cell voltage of 0.76 V at a galvanostatic current density of 0.25 A/cm2 under humid H2, which is clearly an active and stable anode material for SOFCs.
Keywords	Solid oxide fuel cell, Oxide anode, Phase conversion, Electrodics, Fuel flexibility
Remark	https://doi.org/10.1016/j.electacta.2018.07.132 Link

ID=484

Assessment of layered La2-x(Sr,Ba)xCuO4-δ oxides as potential cathode materials for SOFCs

Authors	Anna Niemczyk, Anna Olszewska, Zhihong Du, Zijia Zhang, Konrad Świerczeka, Hailei Zhao
Source	International Journal of Hydrogen Energy Volume: 43, Issue: 32, Pages: 15492-15504 Time of Publication: 2018
Abstract	In this paper, selected layered cuprates with La2-x(Sr,Ba)xCuO4-δ formula are evaluated as candidate cathode materials for Solid Oxide Fuel Cells. Two synthesis routes, a typical solid state reaction and a sol-gel method yield well-crystallized La1.5Sr0.5CuO4-δ, La1.6Ba0.4CuO4-δ and La1.5Sr0.3Ba0.2CuO4-δ materials having tetragonal I4/mmm space group, but differing in morphology of the powder. Fine powders obtained using sol-gel route seem to be more suitable for preparation of the porous cathode layers having good adhesion on the solid electrolyte, but powders obtained after the solid state route can be also successfully utilized. Investigations of structural and transport properties, the oxygen nonstoichiometry and its change with temperature, thermal expansion, as well as chemical and thermal stability are systematically performed, to evaluate and compare basic physicochemical properties of the oxides. At room temperature the average valence state of copper is found to be in 2.2–2.35 range, indicating oxygen deficiency in all of the compounds, which further increases with temperature. The conducted high-temperature X-ray diffraction tests reveal moderate, but anisotropic thermal expansion of La2-x(Sr,Ba)xCuO4-δ, with higher expansion at temperatures above 400 °C occurring along a-axis, due to the oxygen release. However, the corresponding chemical expansion effect is small and the materials possess moderate thermal expansion in the whole studied temperature range. All compounds show relatively high electrical conductivity at the elevated temperatures, related to the Cu2+/Cu3+ charge transfer, with the highest values recorded for La1.5Sr0.5CuO4-δ. Comprehensive studies of chemical stability of the selected La1.5Sr0.5CuO4-δ material with La0.8Sr0.2Ga0.8Mg0.2O3-δ solid electrolyte revealed complex behavior, with stability being dependent apart from temperature, also on morphology of the powders. A model describing such behavior is presented. While it is possible to minimize reactivity and characterize electrochemical properties of the La1.5Sr0.5CuO4-δ-based cathode layer, usage of the buffer layer is indispensable to maintain full stability. It is shown that mutual chemical compatibility of La1.5Sr0.5CuO4-δ and commonly used La0.4Ce0.6O2-δ buffer layer material is excellent, with no reactivity even at 1000 °C for prolonged time. Laboratory-scale fuel cell with the La1.5Sr0.5CuO4-δ cathode sintered at the optimized temperature is able to deliver 0.16 W cm−2 at 800 °C while fueled with wet hydrogen.
Keywords	Layered cuprates, Cathodic polarization, Chemical stability, LSGM, Buffer layer, SOFC
Remark	https://doi.org/10.1016/j.ijhydene.2018.06.119 Link

ID=482

Optimization and Electrochemical Properties of Double Perovskite NdBaCo2O6–δ ·LaBaCo2O5+δ as Cathode Material for Solid Oxide Fuel Cell

Authors	Jia, Zhenyuan; Wang, Peida; Zhong, Yuhan; Mei, Huayue
Source	Journal of Nanoelectronics and Optoelectronics Volume: 13, Issue: 5, Pages: 749-757(9) Time of Publication: 2018
Abstract	In this paper, the double perovskite structure NdBaCo2O6–δ ·LaBaCo2O5+δ was used as cathode material for solid oxide fuel cell (SOFC). The cathode material was prepared using sol in situ composite method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements systems. The NdBaCo2O6–δ and (Ce, Gd, O) were prepared to get NdBaCo2O6–δ –xCe0.8Gd0.1O1.75 (x = 0–10 wt%) and with the increase of the compound (Ce, Gd, O), the electrode polarization surface resistance changes. The polarization resistance at 700 °C was only 0.032 Ω cm2. The output power of single battery was 0.363 W/cm2. The sol–gel method was used to replace Co with Fe and LaBaCo2–x Fe x O5+δ (x = 0.0, 0.3, 0.5, 0.8) was prepared. It was observed that under different Fe contents, the polarization resistance of the composite cathode material LaBaCo2–x Fe x O5+δ decreases first and then increases. When x = 0.3, the minimum polarization resistance can be obtained, however, with the increase of temperature, the polarization resistance of the composite cathode material further reduced.
Remark	DOI: https://doi.org/10.1166/jno.2018.2320 Link

ID=481

Electrochemical and degradation study of Sr0.6Na0.4SiO3-δ

Authors	Kapil Sood, Jyoti Kaswan, Surinder P. Singh, Truls Norby, Suddhasatwa Basu
Source	Journal of Solid State Electrochemistry Volume: 22, Issue: 10, Pages: 3009–3013 Time of Publication: 2018
Abstract	The high ionic conductivity of Na-doped SrSiO3 (SNS) is a topic of interest due to contradictory reports on its conductivity and stability by various groups. From a recent NMR study, it is proposed that Na+ is mainly responsible for ionic conductivity in an amorphous Na2Si2O5 phase present in SNS. The present study further extends to determine experimentally the ion transport number as well as material characteristics after long time annealing at 600 °C. The conductivity behavior of as-sintered and annealed nominally Sr0.6Na0.4SiO3-δ is investigated and a sharp fall (~ 2 order magnitude) of the same at 800 °C is found. An XPS study is included for comprehensive understanding of conductivity and degradation behavior of SNS material. On basis of the collective results, we propose a rational description of the conduction and material degradation of SNS.
Keywords	SrSiO3, Transport number, SOFC, Ionic conductivity, Protonic conductivity
Remark	Link

ID=480

Novel ReBaCo1.5Mn0.5O5+δ (Re: La, Pr, Nd, Sm, Gd and Y) perovskite oxide: influence of manganese doping on the crystal structure, oxygen nonstoichiometry, thermal expansion, transport properties, and application as a cathode material in solid oxide f

Authors	Anna Olszewska, Zhihong Du, Konrad Świerczek, Hailei Zhao and Bogdan Dabrowski
Source	Journal of Materials Chemistry A Issue: 6, Pages: 13271-13285 Time of Publication: 2018
Abstract	In this work, a novel series of Mn-containing ReBaCo1.5Mn0.5O5+δ (Re: selected rare earth elements) perovskite-type oxides is studied, with systematic measurements of physicochemical properties being reported. Comparison with the very well-studied, parent ReBaCo2O5+δ allows determination of the role of the introduced manganese concerning modification of the crystal structure at room temperature and its evolution at high temperatures, variation of the oxygen content, thermal stability of the materials, and total electrical conductivity, as well as thermal and chemical expansion. Generally, the presence of Mn cations does not affect the tendency for A-site cation ordering, resulting in an increased unit cell volume of the compounds, as well as causing an increase of the oxygen content. Reduced thermal expansion, together with high values of electrical conductivity and suitable thermal stability, makes the compounds containing larger Re3+ cations attractive from the point of view of application as cathode materials in solid oxide fuel cells. Chemical compatibility studies reveal the sufficient stability of the considered perovskites in relation to Ce0.8Gd0.2O2−δ solid electrolyte, while unexpected, somewhat increased reactivity towards La0.8Sr0.2Ga0.8Mg0.2O3−δ and La0.4Ce0.6O2−δ is also reported. Furthermore, the electrochemical tests of the symmetric cells show strong dependence of the polarization resistance of the electrode on the synthesis and sintering temperatures. For the selected and optimized NdBaCo1.5Mn0.5O5+δ layer employed in the electrolyte-supported (LSGM) symmetric cell with a CGO buffer layer, the cathodic polarization resistance is 0.043 Ω cm2 at 900 °C. A wet hydrogen-fuelled button-type cell with the NdBaCo1.5Mn0.5O5+δ-based cathode is also prepared, delivering the maximum power density exceeding 1.3 W cm−2 at 850 °C.
Remark	DOI: 10.1039/C8TA03479F Link

ID=479

High performance ceramic nanocomposite fuel cells utilizing LiNiCuZn-oxide anode based on slurry method

Authors
Source	International Journal of Hydrogen Energy Time of Publication: 2018
Abstract	A multi-oxide material LiNiCuZn-oxide was prepared through a slurry method as an anode for ceramic nanocomposite fuel cell (CNFC). The CNFCs using this anode material, LSCF as cathode material and a composite electrolyte consisting of CaSm co-doped CeO2 and (NaLiK)2CO3 produced ∼1.03 W/cm2 at 550 °C due to efficient reaction kinetics at the electrodes and high ionic transport in the nanocomposite electrolyte. The electrochemical impedance spectroscopy revealed low ionic transport losses (0.238 Ω cm2) and low polarization losses (0.124 Ω cm2) at the electrodes. The SEM measurements revealed the porous microstructures of the composite materials at electrode and the dense mixture of CaSm co-doped CeO2 and (NaLiK)2CO3. The Brunauer-Emmett-Teller (BET) analysis revealed high surface areas, 4.1 m2/g and 3.8 m2/g, of the anode and cathode respectively. This study provides a promising material for high performance CNFCs.
Keywords	Ceramic, Conductivity, Fuel cell, Multi-oxide, Nanocomposite, Synthesis
Remark	https://doi.org/10.1016/j.ijhydene.2018.03.232 Link

ID=478

Enhanced Performance of Gadolinia-Doped Ceria Diffusion Barrier Layers Fabricated by Pulsed Laser Deposition for Large-Area Solid Oxide Fuel Cells

Authors
Source	ACS Appl. Energy Mater. Time of Publication: 2018
Abstract	Diffusion barrier layers are typically introduced in solid oxide fuel cells (SOFCs) to avoid reaction between state-of-the-art cathode and electrolyte materials, La1–xSrxCo1–yFeyO3-δ and yttria-stabilized zirconia (YSZ), respectively. However, commonly used layers of gadolinia-doped ceria (CGO) introduce overpotentials that significantly reduce the cell performance. This performance decrease is mainly due to the low density achievable with traditional deposition techniques, such as screen printing, at acceptable fabrication temperatures. In this work, perfectly dense and reproducible barrier layers for state-of-the-art cells (∼80 cm2) were implemented, for the first time, using large-area pulsed laser deposition (LA-PLD). In order to minimize cation interdiffusion, the low-temperature deposited barrier layers were thermally stabilized in the range between 1100 and 1400 °C. Significant enhanced performance is reported for cells stabilized at 1150 °C showing excellent power densities of 1.25 W·cm–2 at 0.7 V and at a operation temperature of 750 °C. Improved cells were finally included in a stack and operated in realistic conditions for 4500 h revealing low degradation rates (0.5%/1000 h) comparable to reference cells. This approach opens new perspectives in manufacturing highly reproducible and stable barrier layers for a new generation of SOFCs.
Keywords	Cation diffusion at CGO/YSZ interface; diffusion barrier layer; gadolinia doped ceria (CGO); pulsed laser deposition (PLD); solid oxide fuel cells (SOFCs); SrZrO3
Remark	DOI: 10.1021/acsaem.8b00039 Link

ID=477

Solid oxide fuel cells incorporating doped lanthanum gallate films deposited by radio-frequency magnetron sputtering at various Ar/O2 ratios and annealing conditions

Authors	Yi-Xin Liu , Sea-Fue Wang, Yung-Fu Hsu, Wan-Yun Yeh
Source	Surface and Coatings Technology Volume: 344, Pages: 507-513 Time of Publication: 2018
Abstract	In this study, we prepared solid oxide fuel cells (SOFCs) incorporating a dense La0.87Sr0.13Ga0.88Mg0.12O3−δ (LSGM) film deposited by radio-frequency (RF) magnetron sputtering on an NiO-Sm0.2Ce0.8O2−δ (NiO-SDC) anode substrate. The influences of the Ar-O2 deposition atmosphere and the subsequent annealing conditions on the characteristics of the LSGM film and on the performance of the resulting SOFCs was investigated. LSGM targets with La0.76Sr0.24Ga0.63Mg0.37O3−δ composition and a deposition atmosphere with Ar/O2 ratios ranging from 10/0 to 5/5 were used throughout the study. Owing to the amorphous nature of the as-deposited LSGM films, the film deposited in an Ar/O2 = 10/0 atm required post-annealing at 950 °C for 4 h for crystallization and removal of the SrLaGa2O7 content, while the films deposited at lower Ar/O2 ratios required higher crystallization temperatures: for instance, the films deposited at Ar/O2 = 6/4 had to be annealed at 1100 °C for 2 h. The anode-supported substrates were then screen-printed with a La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF)-LSGM cathode layer and fired to form SOFC cells. The single cell incorporating an LSGM film with La0.87Sr0.13Ga0.88Mg0.12O3−δ composition deposited in a pure Ar atmosphere exhibited the lowest cell resistance and thus the highest maximum power density (MPD) at all operating temperatures. The total resistance of the single cell incorporating a 4.3 μm-thick LSGM film decreased from 0.386 to 0.121 Ω cm2 as the temperature increased from 650 to 850 °C, and the open circuit voltages ranged from 0.941 to 0.861 V. The maximum power density of the single cell was 0.422, 0.736, and 1.105 W cm−2 at 650, 750, and 850 °C, respectively.
Keywords	Solid oxide fuel cell, Sputtering, Electrolyte, Doped lanthanum gallate
Remark	https://doi.org/10.1016/j.surfcoat.2018.03.073 Link

ID=474

Lanthanum doped strontium titanate - ceria anodes: deconvolution of impedance spectra and relationship with composition and microstructure

Authors	Dariusz Burnat, Gunnar Nurk, Lorenz Holzer, Michal Kopecki, Andre Heel
Source	Journal of Power Sources Volume: 385, Pages: 62-75 Time of Publication: 2018
Abstract	Electrochemical performance of ceramic (Ni-free) SOFC anodes based on La0.2Sr0.7TiO3-δ (LST) and Gd0.1Ce0.9O1.95-δ (CGO) is thoroughly investigated. Microstructures and compositions are systematically varied around the percolation thresholds of both phases by modification of phase volume fractions, particle size distributions and firing temperature. Differential impedance spectroscopy was performed while varying gas composition, electrical potential and operating temperature, which allows determining four distinct electrode processes. Significant anode impedances are measured at low frequencies, which in contrast to the literature cannot be linked with gas concentration impedance. The dominant low frequency process (∼1 Hz) is attributed to the chemical capacitance. Combined EIS and microstructure investigations show that the chemical capacitance correlates inversely with the available surface area of CGO, indicating CGO surface reactions as the kinetic limitation for the dominant anode process and for the associated chemical capacitance. In anodes with a fine-grained microstructure this limitation is significantly smaller, which results in an impressive power output as high as 0.34 Wcm−2. The anodes show high redox stability by not only withstanding 30 isothermal redox cycles, but even improving the performance. Hence, compared to conventional Ni-cermet anodes the new LST-CGO material represents an interesting alternative with much improved redox-stability.
Keywords	SOFC, LST, Microstructure analysis, Electrochemical impedance, Spectroscopy, Redox Anodes
Remark	https://doi.org/10.1016/j.jpowsour.2018.03.024 Link

ID=464

Performance evaluation of Mn and Fe doped SrCo 0.9 Nb 0.1 O 3-δ cathode for IT-SOFC application

Authors	Lokesh Bele, R.K. Lenka, P.K. Patro, L.M. uhmood, T. Mahata and P.K. Sinha
Source	IOP Conference Series: Materials Science and Engineering Volume: 310
Abstract	Cathode materials of Mn and Fe doped SrCo0.9Nb0.1O3-δ, are synthesized by solid state route for intermediate temperature fuel cell applications. Phase pure material is obtained after calcining the precursors at 1100oC. Phase compatibility is observed between this novel cathode material with gadolinia doped ceria (GDC)electrolyte material as reflected in the diffraction pattern. The state of art YSZ electrolyte is not compatible with this cathode material. Average thermal expansion coefficient of the material varies between 17 to 22 X 10-6 K-1 on doping, from room temperature to 800 oC. Increase in thermal expansion coefficient is observed with Mn and Fe doping associated with the loss of oxygen from the crystal. The electrical conductivity of the cathode material decreases with Fe and Mn doping. Mn doped samples show lowest conductivity. From the symmetric cell measurement lower area specific resistance (0.16 Ω-cm2) is obtained for un-doped samples, at 850 oC. From the initial results it can be inferred that Mn/Fe doping improves neither the thermal expansion coefficient nor the electrochemical activity.
Remark	Link

ID=463

Does the conductivity of interconnect coatings matter for solid oxide fuel cell applications?

Authors	Claudia Goebel, Alexander G. Fefekos, Jan-Erik Svensson, Jan Froitzheim
Source	Journal of Power Sources Volume: 383, Pages: 110-114 Time of Publication: 2018
Abstract	The present work aims to quantify the influence of typical interconnect coatings used for solid oxide fuel cells (SOFC) on area specific resistance (ASR). To quantify the effect of the coating, the dependency of coating thickness on the ASR is examined on Crofer 22 APU at 600 °C. Three different Co coating thicknesses are investigated, 600 nm, 1500 nm, and 3000 nm. Except for the reference samples, the material is pre-oxidized prior to coating to mitigate the outward diffusion of iron and consequent formation of poorly conducting (Co,Fe)3O4 spinel. Exposures are carried out at 600 °C in stagnant laboratory air for 500 h and subsequent ASR measurements are performed. Additionally the microstructure is investigated with scanning electron microscopy (SEM). On all pre-oxidized samples, a homogenous dense Co3O4 top layer is observed beneath which a thin layer of Cr2O3 is present. As the ASR values range between 7 and 12 mΩcm2 for all pre-oxidized samples, even though different Co3O4 thicknesses are observed, the results strongly suggest that for most applicable cases the impact of the coating on ASR is negligible and the main contributor is Cr2O3.
Keywords	Solid oxide fuel cell, Interconnect, Corrosion, Coating, Area specific resistance, Cr2O3
Remark	https://doi.org/10.1016/j.jpowsour.2018.02.060 Link

ID=462

Amorphous-cathode-route towards low temperature SOFC

Authors	Andrea Cavallaro, Stevin S. Pramana, Enrique Ruiz-Trejo, Peter C. Sherrell, Ecaterina Ware, John A. Kilner and Stephen J. Skinner
Source	Volume: 2, Pages: 862-875 Time of Publication: 2018
Abstract	Lowering the operating temperature of solid oxide fuel cell (SOFC) devices is one of the major challenges limiting the industrial breakthrough of this technology. In this study we explore a novel approach to electrode preparation employing amorphous cathode materials. La0.8Sr0.2CoO3−δ dense films have been deposited at different temperatures using pulsed laser deposition on silicon substrates. Depending on the deposition temperature, textured polycrystalline or amorphous films have been obtained. Isotope exchange depth profiling experiments reveal that the oxygen diffusion coefficient of the amorphous film increased more than four times with respect to the crystalline materials and was accompanied by an increase of the surface exchange coefficient. No differences in the surface chemical composition between amorphous and crystalline samples were observed. Remarkably, even if the electronic conductivities measured by the Van Der Pauw method indicate that the conductivity of the amorphous material was reduced, the overall catalytic properties of the cathode itself were not affected. This finding suggests that the rate limiting step is the oxygen mobility and that the local electronic conductivity in the amorphous cathode surface is enough to preserve its catalytic properties. Different cathode materials have also been tested to prove the more general applicability of the amorphous-cathode route.
Remark	DOI: 10.1039/C7SE00606C Link

ID=460

Co-deficient PrBaCo2−xO6−δ perovskites as cathode materials for intermediate-temperature solid oxide fuel cells: Enhanced electrochemical performance and oxygen reduction kinetics

Authors	Likun Zhang, Shuli Li, Tian Xia, Liping Sun, Lihua Huo, Hui Zhao
Source	International Journal of Hydrogen Energy Volume: 43, Issue: 7, Pages: 3761-3775 Time of Publication: 2018
Abstract	Co-deficient PrBaCo2−xO6−δ perovskites (x = 0, 0.02, 0.06 and 0.1) are synthesized by a solid-state reaction, and the effects of Co-deficiency on the crystal structure, oxygen nonstoichiometry and electrochemical properties are investigated. The PrBaCo2−xO6−δ samples have an orthorhombic layered perovskite structure with double c axis. The degree of oxygen nonstoichiometry increases with decreasing Co content (0 ≤ x ≤ 0.06) and then slightly decreases at x = 0.1. All the samples exhibit the electrical conductivity values of >300 S cm−1 in the temperature range of 100–800 °C in air, which match well the requirement of cathode. With significantly enhanced electrochemical performance and good chemical compatibility between PrBaCo2−xO6−δ and CGO, this system of Co-deficient perovskite is promising cathode material for IT-SOFCs. Among all these components, PrBaCo1.94O6−δ gives lowest polarization resistance of 0.059 Ω cm2 at 700 °C in air. When tested as cathode in fuel cell, the anode-supported Ni-YSZ\|YSZ\|CGO\|PrBaCo1.94O6−δ cell delivers a maximum peak power density of 889 mW cm−2 at 650 °C, which is higher than that of PrBaCoO6−δ cathode-based cell (764 mW cm−2). The oxygen reduction kinetics at the PrBaCo1.94O6−δ cathode interface is also explored, and the rate-limiting steps for oxygen reduction reaction are determined.
Keywords	Intermediate-temperature solid oxide fuel cells, Cathode material, Layered perovskite, Electrochemical performance, Oxygen reduction kinetics
Remark	https://doi.org/10.1016/j.ijhydene.2018.01.018 Link

ID=459

Deposition of nickel oxide-yttria stabilized zirconia thin films by reactive magnetron sputtering

Authors	A.A .Solovyev, A.M. Lebedynskiy, A.V. Shipilova, I.V.Ionov, E.A. Smolyanskiy, A.L. Lauk, G.E. Remnev
Source	International Journal of Hydrogen Energy Time of Publication: 2018
Abstract	Nickel oxide-yttria stabilized zirconia (NiO-YSZ) thin films were reactively sputter-deposited by pulsed direct current magnetron sputtering from the Ni and Zr-Y targets onto heated commercial NiO-YSZ substrates. The microstructure and composition of the deposited films were investigated with regard to application as thin anode functional layers (AFLs) for solid oxide fuel cells (SOFCs). The porosity and microstructure of both as-deposited and annealed at 1200 °C for 2 h AFLs were studied by scanning electron microscopy and X-ray diffractometry and controlled by changing the deposition process parameters. The results show that annealing in air at 1200 °C is required to improve film crystallinity and structural homogeneity. NiO-YSZ films have pores and grains of several hundred nanometers in size after reduction in hydrogen. Adhesion of deposited films was evaluated by scratch test. Anode-supported solid oxide fuel cells with the magnetron sputtered anode functional layer, YSZ electrolyte and La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathode were fabricated and tested. Influence of thin anode functional layer on performance of anode-supported SOFCs was studied. It was shown that electrochemical properties of the single fuel cells depend on the NiO volume content in the NiO-YSZ anode functional layer. Microstructural changes of NiO-YSZ layers after nickel reduction-oxidation (redox) cycling were studied. After nine redox cycles at 750 °C in partial oxidation conditions, the cell with the anode NiO-YSZ layer showed stable open circuit voltage values with the power density decrease by 11% only.
Keywords	Solid oxide fuel cells, Magnetron sputtering, Thin-film anode, Microstructure, Redox cycling
Remark	Available online 7 February 2018, https://doi.org/10.1016/j.ijhydene.2018.01.076 Link

ID=458

Solid oxide fuel cells with apatite-type lanthanum silicate-based electrolyte films deposited by radio frequency magnetron sputtering

Authors	Yi-Xin Liu, Sea-Fue Wang, Yung-Fu Hsu, Chi-Hua Wang
Source	Journal of Power Sources Volume: 381, Pages: 101-106 Time of Publication: 2018
Abstract	In this study, solid oxide fuel cells (SOFCs) containing high-quality apatite-type magnesium doped lanthanum silicate-based electrolyte films (LSMO) deposited by RF magnetron sputtering are successfully fabricated. The LSMO film deposited at an Ar:O2 ratio of 6:4 on an anode supported NiO/Sm0.2Ce0·8O2-δ (SDC) substrate followed by post-annealing at 1000 °C reveals a uniform and dense c-axis oriented polycrystalline structure, which is well adhered to the anode substrate. A composite SDC/La0·6Sr0·4Co0·2Fe0·8O3-δ cathode layer is subsequently screen-printed on the LSMO deposited anode substrate and fired. The SOFC fabricated with the LSMO film exhibits good mechanical integrity. The single cell with the LSMO layer of ≈2.8 μm thickness reports a total cell resistance of 1.156 and 0.163 Ωcm2, open circuit voltage of 1.051 and 0.982 V, and maximum power densities of 0.212 and 1.490 Wcm−2 at measurement temperatures of 700 and 850 °C, respectively, which are comparable or superior to those of previously reported SOFCs with yttria stabilized zirconia electrolyte films. The results of the present study demonstrate the feasibility of deposition of high-quality LSMO films by RF magnetron sputtering on NiO-SDC anode substrates for the fabrication of SOFCs with good cell performance.
Keywords	Solid oxide fuel cell, Sputtering, Electrolyte Doped lanthanum silicate
Remark	https://doi.org/10.1016/j.jpowsour.2018.02.007 Link

ID=457

Electrical conductivity of NiMo–based double perovskites under SOFC anodic conditions

Authors	Sabrina Presto, Pravin Kumar, Salil Varma, Massimo Viviani, Prabhakar Singh
Source	International Journal of Hydrogen Energy Volume: 43, Issue: 9, Pages: 4528-4533 Time of Publication: 2018
Abstract	Three different materials are prepared by chemical reaction route, Sr2NiMoO6 (SNM00), Sr1.96La004NiMoO6 (SLNM04) and Sr1.99Ce0.01NiMoO6 (SCNM01) and conductivity is measured under reducing atmosphere, in order to study their suitability as anode materials in SOFC application. Selected materials correspond to compositions reported with highest conductivity in air at operative temperatures of a SOFC among the systems SLNM (Sr2−xLaxNiMoO6, 0.02 ≤ x ≤ 0.10) and SCNM (Sr2−xCexNiMoO6, 0.01 ≤ x ≤ 0.05). The end member Sr2NiMoO6 (SNM) is also considered as reference. Their conductivities considerably increase in wet hydrogen and follow Arrhenius behavior with lower activation energy. Effects of reduction on microstructure and phase stability are also studied by scanning electron microscopy and X–ray diffraction. The enhancement in conductivity is discussed in terms of defects chemistry. Amongst all measured samples, SLNM04 shows the highest conductivity in reducing atmosphere without phase degradation, which makes it a promising anode material for Solid Oxide Fuel Cells (SOFC).
Keywords	Double perovskite Reduction Electrical conductivity Anodic materials SOFC
Remark	https://doi.org/10.1016/j.ijhydene.2018.01.066 Link

ID=456

Effect of sintering temperature on the performance of composite La0.6Sr0.4Co0.2Fe0.8O3–Ce0.9Gd0.1O2 cathode for solid oxide fuel cells

Authors	A.A. Solovyev, I.V. Ionov, A.V. Shipilova, P.D. Maloney
Source	Journal of Electroceramics Time of Publication: 2018
Abstract	Studied here are the effects of sintering temperature of La0.6Sr0.4Co0.2Fe0.8O3-Ce0.9Gd0.1O2 (LSCF–CGO) cathodes on their microstructure and performance of intermediate-temperature solid oxide fuel cells (IT-SOFC). Phase composition, microstructure and electrochemical properties were investigated by X-ray powder diffraction (XRD), scanning electron microscopy and current-voltage characteristics measurement, respectively. The electrochemical performances of Ni–YSZ anode-supported SOFC having YSZ electrolyte (4 μm) with CGO interlayer (2 μm) are studied with LSCF–CGO (50:50 wt%) cathodes in the temperature range 600–800 °C using H2 as fuel and air as oxidant. The cathode microstructure was found to be less dense and to contain smaller grains as the sintering temperature was decreased in the range 1250–1150 °C. Results reveal that sintering temperature and electrode morphology have strong influence on electrochemical performances of the IT-SOFC. Highest maximum power density of ∼1.26 W/cm2 is achieved during cell testing at 800 °C with a cathode sintered at 1200 °C. However, cells with in-situ sintered LSCF–CGO cathode showed highest power density at 600 °C (0.48 W/cm2) because there is no particle coarsening at low sintering temperatures.
Keywords	LSCF–CGO, Composite cathode, Microstructure,, Performanc, Intermediate-temperature solid oxide fuel cells
Remark	https://doi.org/10.1007/s10832-018-0114-5, First Online: 29 January 2018 Link

ID=453

Structural and electrochemical characterization of BaCe0.7Zr0.2Y0.05Zn0.05O3 as an electrolyte for SOFC-H

Authors	Ahmed Afif, Nikdalila Radenahmad, Chee Ming Lim, Quintin Cheok, Md. Aminul Islam, Seikh Mohammad Habibur Rahman, Abul Kalam Azad
Source	IOP Conf. Series: Materials Science and Engineering Volume: 121 Time of Publication: 2016
Abstract	As a potential electrolyte for proton-conducting solid oxide fuel cells (SOFC-Hs)and to get better protonic conductivity and stability, zinc doped BCZY material has been found to be promising. In this study, we report a new composition of proton conductors BaCe0.7Zr0.2Y0.05Zn0.05O3 (BCZYZn5) which was investigated using XRD, SEM and conductivity measurements. Rietveld refinement of the XRD data revel a cubic perovskite structure with Pm-3m space group. BaCe0.7Zr0.2Y0.05Zn0.05O3 shows cell parameter a = 4.3452(9) Å. Scanning electron microscopy images shows that the grain sizes are large and compact which gives the sample high density and good protonic conductivity. The total conductivity in wet atmosphere is significantly higher than that of dry condition and the conductivity was found to be 0.276 x 10-3 Scm-1 and 0.204 x 10-3 Scm-1 at 600°C in wet and dry Ar, respectively. This study indicated that perovskite electrolyte BCZYZn5 is a promising material for the next generation intermediate temperature solid oxide fuel cells (IT-SOFCs).
Remark	Link

ID=451

Fabrication and characterization of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF)-Ce0.9Gd0.1O1.95 (GDC) composite thick film for anode supported solid oxide fuel cells

Authors	Atul P. Jamale, C. H. Bhosale, L. D. Jadhav
Source	Journal of Materials Science: Materials in Electronics Volume: 27, Issue: 1, Pages: 795–799 Time of Publication: 2016
Abstract	Nowadays, the commercialization of solid oxide fuel cell (SOFC) is impeded by the chemical compatibility and polarization losses in association with electrode/electrolyte interface. Thus, to minimize these difficulties, the thick film of LSCF-GDC (50:50 wt%) composite was deposited onto GDC electrolyte to form perfect LSCF-GDC/GDC structure. The chemically compatibility of LSCF-GDC upon sintering of 1000 °C was confirmed from the X-ray diffraction studies. Typically, the film with 15 μm thickness possesses the porous structure, availing the free path for oxygen diffusion. The electrochemical impedance analysis of symmetric cell with LSCF-GDC as an electrode implies the relaxation of charge transfer and electrochemical reduction reaction with temperature. The NiO-GDC (30:70 wt%) supported SOFC with GDC and LSCF-GDC as an electrolyte and cathode, respectively was tested for their performance. The cell generates the maximum powder density of 315 μWcm−2 at 500 °C.
Remark	Link

ID=448

Copper Iron Conversion Coating for Solid Oxide Fuel Cell Interconnects

Authors	Jan Gustav Grolig, Patrik Alnegren, Jan Froitzheim, Jan-Erik Svensson
Source	Journal of Power Sources Volume: 297, Pages: 534-539 Time of Publication: 2015
Abstract	A conversion coating of iron and copper was investigated with the purpose of increasing the performance of Sanergy HT as a potential SOFC interconnect material. Samples were exposed to a simulated cathode atmosphere (air, 3 % H2O) for durations of up to 1000 h at 850 °C. Their performance in terms of corrosion, chromium evaporation and electrical resistance (ASR) was monitored and compared to uncoated and cobalt-coated Sanergy HT samples. The copper iron coating had no negative effects on corrosion protection and decreased chromium evaporation by about 80%. An Area Specific Resistance (ASR) of 10 mΩcm2 was reached after 1000 h of exposure. Scanning Electron Microscopy revealed well adherent oxide layers comprised of an inner chromia layer and an outer spinel oxide layer.
Remark	https://doi.org/10.1016/j.jpowsour.2015.06.139 Link

ID=442

Effect of Firing Temperature on the Kinetics of Oxygen Reduction in La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) Cathodes for Solid Oxide Fuel Cells

Author	Brage Braathen Kjeldby
Source	dissertation Time of Publication: 2015
Remark	Norwegian University of Science and Technology, Department of Materials Science and Engineering Link

ID=436

The Effect of Ni Doping on the Performance and Electronic Structure of LSCF Cathodes Used for IT-SOFCs

Authors	Alessandro Longo, Leonarda F. Liotta, Dipanjan Banerjee, Valeria La Parola, Fabrizio Puleo, Chiara Cavallari, Christoph J. Sahle, Marco Moretti Sala, and Antonino Martorana
Source	J. Phys. Chem.: C Time of Publication: 2017
Abstract	We investigated the effect of nickel doping on the electronic structure and performance of nanostructured La0.6Sr0.4Co0.2Fe0.8–0.03Ni0.03O3−δ prepared by the one-pot sol–gel method. The commercial undoped La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCF0.8) was used as reference. Moreover, for comparison, Ni (3 mol %) was deposited by wetness impregnation over the La0.6Sr0.4Co0.2Fe0.8O3−δ. We show by in situ X-ray absorption spectroscopy at 900 °C under air flow that nickel enters the B perovskite site of the material and favors the stabilization of the cobalt oxidation state, as evidenced by the delay in the decrease of the average Co valence with respect to undoped samples. Our results are further supported by in situ X-ray Raman spectroscopy (XRS) that allowed us to monitor the temperature evolution of the O K-edge. XRS evidences that nickel-doped LSCF shows unmodified O2p-TM3d density of states, which proves that the Co oxidation state is preserved. Electrochemical impedance spectroscopy measurements were carried out over half-cell systems consisting of LSCF-based materials deposited onto a Ce0.8Gd0.2O2−δ electrolyte. The improvement of the electrochemical performances of the Ni-doped La0.6Sr0.4Co0.2Fe0.8–0.03Ni0.03O3−δ sample with respect to a reference Ni-impregnated LSCF is attributed to the stabilization of the TM-O6 structural units, which were recently proposed as the functional units for oxygen reduction.
Remark	DOI: 10.1021/acs.jpcc.7b07626 Link

ID=435

Protonic Conductors for Intermediate Temperature Fuel Cell Electrolytes: Superprotonic CsH2PO4 Stabilization and in-Doped SnP2O7 Structure Study

Author	Heber Jair Martinez Salinas
Source	Dissertation Time of Publication: 2017
Remark	The University of Texas at El Paso Link

ID=434

Optimisation of growth parameters to obtain epitaxial Y-doped BaZrO3 proton conducting thin films

Authors
Source	Volume: 314, Pages: 9–16 Time of Publication: 2018
Abstract	We hereby report developments on the fabrication and characterization of epitaxial thin films of proton conducting Y-doped BaZrO3 (BZY) by pulsed laser deposition (PLD) on different single crystal substrates (MgO, GdScO3, SrTiO3, NdGaO3, LaAlO3 and sapphire) using Ni-free and 1% Ni-containing targets. Pure, high crystal quality epitaxial films of BZY are obtained on MgO and on perovskite-type substrates, despite the large lattice mismatch. The deposition conditions influence the morphology, cell parameters and chemical composition of the film, the oxygen partial pressure during film growth being the most determining. Film characterization was carried out using X-ray diffraction, transmission electron and atomic force microscopies, wavelength dispersive X-ray spectroscopy and angle-resolved X-ray photoelectron spectroscopy. All films show a slight tetragonal distortion that is not directly related to the substrate-induced strain. The proton conductivity of the films depends on deposition conditions and film thickness, and for the optimised conditions its total conductivity is slightly higher than the bulk conductivity of the target material (3 mS/cm at 600 °C, in wet 5% H2/Ar). The conductivities are, however, more than one order of magnitude lower than the highest reported in literature and possible reasoning is elucidated in terms of local and extended defects in the films.
Keywords	BaZrO3; Thin film; Electrolyte; Proton conductivity; SOFC; PC-SOFC
Remark	https://doi.org/10.1016/j.ssi.2017.11.002 Link

ID=432

Microstructural engineering and use of efficient poison resistant Au-doped Ni-GDC ultrathin anodes in methane-fed solid oxide fuel cells

Authors
Source	International Journal of Hydrogen Energy Volume: 43, Issue: 2, Pages: 885–893 Time of Publication: 2018
Abstract	Ultrathin porous solid oxide fuel cell (SOFC) anodes consisting of nickel-gadolinia-doped-ceria (Ni-GDC) cermets with a unique porous micro-columnar architecture with intimate contact between the GDC and the Ni phases were made by magnetron sputtering at an oblique deposition angle and characterised in detail by a variety of methods prior to use in hydrogen or methane-fuelled SOFCs. These Ni-GDC anodes exhibited excellent transport properties, were robust under thermal cycling and resistant to delamination from the underlying yttria-stabilised zirconia electrolyte. Similarly prepared Au-doped Ni-GDC anodes exhibited the same morphology, porosity and durability. The gold associated exclusively with the Ni component in which it was present as a surface alloy. Strikingly, whatever their treatment, a substantial amount of Ce3+ persisted in the anodes, even after operation at 800 °C under fuel cell conditions. With hydrogen as fuel, the un-doped and Au-doped Ni-GDC anodes exhibited identical electrochemical performances, comparable to that of much thicker commercial state-of-the-art Ni-GDC anodes. However, under steam reforming conditions with CH4/H2O mixtures the behaviour of the Au-doped Ni-GDC anodes were far superior, exhibiting retention of good power density and dramatically improved resistance to deactivation by carbon deposition. Thus two distinct beneficial effects contributed to overall performance: persistence of Ce3+ in the working anodes could induce a strong metal-support interaction with Ni that enhanced the catalytic oxidation of methane, while formation of a Nisingle bondAu surface alloy that inhibited carbonisation and poisoning of the active nickel surface.
Keywords	SOFC; Ultrathin film anodes; Magnetron sputtering; Gadolinia doped ceria; Carbon-tolerant; Gold doping
Remark	https://doi.org/10.1016/j.ijhydene.2017.11.020 Link

ID=429

Three-dimensional printed yttria-stabilized zirconia self-supported electrolytes for solid oxide fuel cell applications

Authors
Source	Journal of the European Ceramic Society Time of Publication: 2017
Abstract	Additive manufacturing represents a revolution due to its unique capabilities for freeform fabrication of near net shapes with strong reduction of waste material and capital cost. These unfair advantages are especially relevant for expensive and energy-demanding manufacturing processes of advanced ceramics such as Yttria-stabilized Zirconia, the state-of-the-art electrolyte in Solid Oxide Fuel Cell applications. In this study, self-supported electrolytes of yttria-stabilized zirconia have been printed by using a stereolithography three-dimensional printer. Printed electrolytes and complete cells fabricated with cathode and anode layers of lanthanum strontium manganite- and nickel oxide-yttria-stabilized zirconia composites, respectively, were electrochemical characterized showing full functionality. In addition, more complex configurations of the electrolyte have been printed yielding an increase of the performance entirely based on geometrical aspects. Complementary, a numerical model has been developed and validated as predictive tool for designing more advanced configurations that will enable highly performing and fully customized devices in the next future.
Keywords	Solid oxide fuel cell, 3D printing, Stereolithography, Yttria-stabilized zirconia, Electrolyte
Remark	Available online 15 November 2017, https://doi.org/10.1016/j.jeurceramsoc.2017.11.033 Link

ID=428

Characteristics of LaCo0.4Ni0.6-xCuxO3-δ ceramics as a cathode material for intermediate-temperature solid oxide fuel cells

Authors	Yi-XinLiu, Sea-Fue Wang,Yung-Fu Hsu, Hung-Wei Kai, Piotr Jasinski
Source	Journal of the European Ceramic Society Time of Publication: 2017
Abstract	In this study, the effects of Cu-ion substitution on the densification, microstructure, and physical properties of LaCo0.4Ni0.6-xCuxO3-δ ceramics were investigated. The results indicate that doping with Cu ions not only enhances the densification but also promotes the grain growth of LaCo0.4Ni0.6-xCuxO3-δ ceramics. The Cu substitution at x ≤ 0.2 can suppress the formation of La4Ni3O10, while the excess Cu triggers the formation of La2CuO4.032 phase. The p-type conduction of LaCo0.4Ni0.6O3-δ ceramic was significantly raised by Cu substitution because the acceptor doping () triggered the formation of hole carriers; this effect was maximized in the case of LaCo0.4Ni0.4Cu0.2O3-δ composition (1480 S cm−1 at 500 °C). Thermogravimetric data revealed a slight weight increase of 0.29% for LaCo0.4Ni0.4Cu0.2O3-δ compact up to 871 °C; this is due to the incorporation of oxygen that creates metal vacancies and additional carriers, partially compensating the conductivity loss due to the spin-disorder scattering. As the temperature of the LaCo0.4Ni0.4Cu0.2O3-δ compacts rose above 871 °C, significant weight loss with temperature was observed because of the release of lattice oxygen to the ambient air as a result of Co (IV) thermal reduction accompanied by the formation of oxygen vacancies. A solid oxide fuel cell (SOFC) single cell with Sm0.2Ce0.8O2-δ (electrolyte) and LaCo0.4Ni0.4Cu0.2O3-δ (cathode) was built and characterized. The Ohmic (0.256 Ω cm2) and polarization (0.434 Ω cm2) resistances of the single cell at 700 °C were determined; and the maximum power density was 0.535 W cm−2. These results show that LaCo0.4Ni0.4Cu0.2O3-δ is a very promising cathode material for SOFC applications.
Keywords	Solid oxide fuel cells, Cell performance, Impedance Cathode
Remark	Available online 8 November 2017, https://doi.org/10.1016/j.jeurceramsoc.2017.11.019 Link

ID=426

Analysis of potential materials for single component fuel cells

Authors	Monica Lin, Ashgar Imran, and Peter Lund
Source	FUNCTIONAL NANOSTRUCTURES PROCEEDINGS Time of Publication: 2017
Abstract	The following paper summarizes the results of systematic analysis on single component fuel cell. This recent technology in the solid oxide fuel cell field consists of a unique layer in place of the conventional three-layers structure. The single layer is a mixture of ionic and semi-conductor material. Surprisingly, the expected short circuit has not shown up. On the contrary, the performance is even higher, as reported in literature [1]. This work aims to compare different combinations of materials in terms of performance. La0.6Sr0.4Co0.2Fe0.8O3-δ(LSCF), LiNi0.8Co0.15Al0.05O2 (NCAL), La0.8Sr0.2CoO3(LSC), LiNiZn oxide (LNZ) and a new kind of material, CuFe2O4 are analysed as semi-conductor material. As ionic conductor, CeO2/Gd (GDC) is mainly tilised. Also, CeO2/Sm (SDC) and CeO2/Sm/Ca SCDC are considered too.
Remark	Link

ID=424

High-temperature properties of (La,Ca)(Fe,Mg,Mo)O3-δ perovskites as prospective electrode materials for symmetrical SOFC

Authors	S.Ya.Istomin, A.V.Morozov, M.M.Abdullayev, M.BatukbJ.Hadermann, S.M.Kazakov, A.V.Sobolev, I.A.Presniakov, E.V.Antipov
Source	Journal of Solid State Chemistry Volume: 258, Pages: 1-10 Time of Publication: 2018
Abstract	La1−yCayFe0.5+x(Mg,Mo)0.5−xO3-δ oxides with the orthorhombic GdFeO3-type perovskite structure have been synthesized at 1573 K. Transmission electron microscopy study for selected samples shows the coexistence of domains of perovskite phases with ordered and disordered B-cations. Mössbauer spectroscopy studies performed at 300 K and 573 K show that while compositions with low Ca-content (La0.55Ca0.45Fe0.5Mg0.2625Mo0.2375O3-δ and La0.5Ca0.5Fe0.6Mg0.175Mo0.225O3-δ) are nearly oxygen stoichiometric, La0.2Ca0.8Fe0.5Mg0.2625Mo0.2375O3-δ is oxygen deficient with δ ≈ 0.15. Oxides are stable in reducing atmosphere (Ar/H2, 8%) at 1173 K for 12 h. No additional phases have been observed at XRPD patterns of all studied perovskites and Ce1−xGdxO2−x/2 electrolyte mixtures treated at 1173–1373K, while Fe-rich compositions (x≥0.1) react with Zr1−xYxO2−x/2 electrolyte above 1273 K. Dilatometry studies reveal that all samples show rather low thermal expansion coefficients (TECs) in air of 11.4–12.7 ppm K−1. In reducing atmosphere their TECs were found to increase up to 12.1–15.4 ppm K−1 due to chemical expansion effect. High-temperature electrical conductivity measurements in air and Ar/H2 atmosphere show that the highest conductivity is observed for Fe- and Ca-rich compositions. Moderate values of electrical conductivity and TEC together with stability towards chemical interaction with typical SOFC electrolytes make novel Fe-containing perovskites promising electrode materials for symmetrical solid oxide fuel cell.
Keywords	Symmetrical solid oxide fuel cell, Perovskites, Crystal structure, High-temperature electrical conductivity
Remark	https://doi.org/10.1016/j.jssc.2017.10.005 Link

ID=420

Performance and stability in H2S of SrFe0.75Mo0.25O3-δ as electrode in proton ceramic fuel cells

Authors	S.Wachowski, M.Polfus, T.Norby
Source	Journal of the European Ceramic Society Volume: 38, Issue: 1, Pages: 163-171 Time of Publication: 2018
Abstract	The H2S-tolerance of SrFe0.75Mo0.25O3-δ (SFM) electrodes has been investigated in symmetric proton ceramic fuel cells (PCFC) with BaZr0.8Ce0.1Y0.1O3-δ (BZCY81) electrolyte. The ionic conductivity of the electrolyte under wet reducing conditions was found to be insignificantly affected in the presence of up to 5000 ppm H2S. The fuel cell exhibited an OCV of about 0.9 V at 700 °C, which dropped to about 0.6 V and 0.4 V upon exposure to 500 and 5000 ppm H2S, respectively, on the fuel side. Post characterization of the fuel cell revealed significant degradation of the anode in terms of microstructure and chemical composition due to formation of sulfides such as SrS, MoS2 and Fe3S4. Nevertheless, the fuel cell was still functional due to the sufficient electronic conductivity of some of these sulfides.
Keywords	Proton ceramic fuel cells (PCFC), Sulfur tolerance, H2S, Strontium ferrite, Barium zirconate
Remark	https://doi.org/10.1016/j.jeurceramsoc.2017.08.020 Link

ID=413

Advanced low-temperature ceramic nanocomposite fuel cells using ultra high ionic conductivity electrolytes synthesized through freeze-dried method and solid-route

Authors
Source	Materials Today Energy Volume: 5, Pages: 338-346 Time of Publication: 2017
Abstract	Low ionic conductivity and slow reaction kinetics often limit the performance of a ceramic nanocomposite fuel cell (CNFC). Here, we report a novel synthesis method, freeze-dried method, to achieve a record high ionic conductivity for nanocomposite electrolytes (>0.5 S/cm) based on Ce0.85Sm0.15O2 (SDC) and a eutectic mixture of Na2CO3, Li2CO3, K2CO3 (NLK). The highest ionic conductivity (0.55 S/cm) was reached by increasing the carbonate content of the electrolyte to 35 wt%. For the sake of comparison, the nanocomposite electrolytes were also prepared through solid-route. Composite anodes and cathodes for complete fuels were prepared from NiO and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF), respectively using both solid-route and freeze-dried nanocomposite electrolytes. Complete fuel cells manufactured from these nanocomposite materials produced ∼1.1 W/cm2 at 550 °C. The EIS measurements revealed low ohmic losses (0.18 Ω cm2) and even lower charge transfer resistance (0.05 Ω cm2). In addition, it was found that the open-circuit-voltage (OCV) of the CNFCs improved from 1.1 V to 1.2 V when a mixture of air and CO2 was supplied as compared to the case when only air was supplied at the cathode. Finally, high temperature X-ray diffraction (HT-XRD) revealed stable structures of SDC, NiO and LSCF up to 600 °C, which shows the thermal stability of these fuel cell materials.
Keywords	Fuel cells, Ceramic, Nanocomposite, Carbonate, Ionic conductivity, Perovskite
Remark	https://doi.org/10.1016/j.mtener.2017.07.017 Link

ID=411

High performance novel gadolinium doped ceria/yttria stabilized zirconia/nickel layered and hybrid thin film anodes for application in solid oxide fuel cells

Authors
Source	Journal of Power Sources Volume: 363, Pages: 251-259 Time of Publication: 2017
Abstract	Magnetron sputtering under oblique angle deposition was used to produce Ni-containing ultra thin film anodes comprising alternating layers of gadolinium doped ceria (GDC) and yttria stabilized zirconia (YSZ) of either 200 nm or 1000 nm thickness. The evolution of film structure from initial deposition, through calcination and final reduction was examined by XRD, SEM, TEM and TOF-SIMS. After subsequent fuel cell usage, the porous columnar architecture of the two-component layered thin film anodes was maintained and their resistance to delamination from the underlying YSZ electrolyte was superior to that of corresponding single component Ni-YSZ and Ni-GDC thin films. Moreover, the fuel cell performance of the 200 nm layered anodes compared favorably with conventional commercially available thick anodes. The observed dependence of fuel cell performance on individual layer thicknesses prompted study of equivalent but more easily fabricated hybrid anodes consisting of simultaneously deposited Ni-GDC and Ni-YSZ, which procedure resulted in exceptionally intimate mixing and interaction of the components. The hybrids exhibited very unusual and favorable IV characteristics, along with exceptionally high power densities at high currents. Their discovery is the principal contribution of the present work.
Keywords	Magnetron sputtering, Oblique angle deposition, Thin film anodes, Layered and hybrid structures, SOFC
Remark	https://doi.org/10.1016/j.jpowsour.2017.07.085 Link

ID=409

Formation of NiO/YSZ functional anode layers of solid oxide fuel cells by magnetron sputtering

Authors	I.V. Ionov, A.A. Solov’ev, A.M. Lebedinskii, A.V. Shipilova, E.A. Smolyanskii, A N. Koval’chuk, A.L. Lauk
Source	Russian Journal of Electrochemistry Volume: 53, Issue: 6, Pages: 670–676 Time of Publication: 2017
Abstract	The decrease in the polarization resistance of the anode of solid-oxide fuel cells (SOFCs) due to the formation of an additional NiO/(ZrO2 + 10 mol % Y2O3) (YSZ) functional layer was studied. NiO/YSZ films with different NiO contents were deposited by reactive magnetron sputtering of Ni and Zr–Y targets. The elemental and phase composition of the films was adjusted by regulating oxygen flow rate during the sputtering. The resulting films were studied by scanning electron microscopy and X-ray diffractometry. Comparative tests of planar SOFCs with a NiO/YSZ anode support, NiO/YSZ functional nanostructured anode layer, YSZ electrolyte, and La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathode were performed. It was shown that the formation of a NiO/YSZ functional nanostructured anode leads to a 15–25% increase in the maximum power density of fuel cells in the working temperature range 500–800°C. The NiO/YSZ nanostructured anode layers lead not only to a reduction of the polarization resistance of the anode, but also to the formation of denser electrolyte films during subsequent magnetron sputtering of electrolyte.
Keywords	SOFC, magnetron sputtering, nanostructured electrode, thin-film anode, polarization resistance
Remark	Link

ID=408

Tailoring the electrode-electrolyte interface of Solid Oxide Fuel Cells (SOFC) by laser micro-patterning to improve their electrochemical performance

Authors	J.A.Cebollero, R.Lahoz, M.A.Laguna-Bercero, A.Larrea
Source	Journal of Power Sources Volume: 360, Pages: 336-344 Time of Publication: 2017
Abstract	Cathode activation polarisation is one of the main contributions to the losses of a Solid Oxide Fuel Cell. To reduce this loss we use a pulsed laser to modify the surface of yttria stabilized zirconia (YSZ) electrolytes to make a corrugated micro-patterning in the mesoscale. The beam of the laser source, 5 ns pulse width and emitting at λ = 532 nm (green region), is computer-controlled to engrave the selected micro-pattern on the electrolyte surface. Several laser scanning procedures and geometries have been tested. Finally, we engrave a square array with 28 μm of lattice parameter and 7 μm in depth on YSZ plates. With these plates we prepare LSM-YSZ/YSZ/LSM-YSZ symmetrical cells (LSM: La1-xSrxMnO3) and determine their activation polarisation by Electrochemical Impedance Spectroscopy (EIS). To get good electrode-electrolyte contact after sintering it is necessary to use pressure-assisted sintering with low loads (about 5 kPa), which do not modify the electrode microstructure. The decrease in polarisation with respect to an unprocessed cell is about 30%. EIS analysis confirms that the reason for this decrease is an improvement in the activation processes at the electrode-electrolyte interface.
Keywords	SOFC, Laser machining, Corrugated surface, Electrode polarisation, Cathode activation, Electrode/electrolyte interface
Remark	https://doi.org/10.1016/j.jpowsour.2017.05.106 Link

ID=406

High conductive (LiNaK)2CO3Ce0.85Sm0.15O2 electrolyte compositions for IT-SOFC applications

Authors	Ieeba Khan, Muhammad Imran Asghar, Peter D.Lund, Suddhasatwa Basu
Source	International Journal of Hydrogen Energy Volume: 42, Issue: 32, Pages: 20904-20909 Time of Publication: 2017
Abstract	Composite electrolytes of lithium, sodium, and potassium carbonate ((LiNaK)2CO3), and samarium doped ceria (SDC) have been synthesized and the carbonate content optimized to study conductivity and its performance in intermediate-temperature solid oxide fuel cell (IT-SOFC). Electrolyte compositions of 20, 25, 30, 35, 45 wt% (LiNaK)2CO3–SDC are fabricated and the physical and electrochemical characterization is carried out using X-ray diffraction, scanning electron microscopy, electrochemical impedance spectroscope, and current–voltage measurements. The ionic conductivity of (LiNaK)2CO3–SDC electrolytes increases with increasing carbonate content. The best ionic conductivity is obtained for 45 wt% (LiNaK)2CO3–SDC composite electrolyte (0.72 S cm−1 at 600 °C) followed by the 35 wt% (LiNaK)2CO3–SDC composite electrolyte (0.55 S cm−1 at 600 °C). The symmetrical cell of the 35 wt% (LiNaK)2CO3–SDC composite electrolyte with lanthanum strontium cobalt ferrite (LSCF) electrode in air gives an area specific resistance of 0.155 Ω cm2 at 500 °C. The maximum power density of the fuel cell using 35 wt% (LiNaK)2CO3–SDC composite electrolyte, composite NiO anode and composite LSCF cathode is found to be 801 mW cm−2 at 550 °C.
Keywords	IT-SOFC, Ternary carbonate–SDC electrolyte, Carbonate loading, Composite electrolytes
Remark	https://doi.org/10.1016/j.ijhydene.2017.05.152 Link

ID=404

Effect of plasma spraying power on LSGM electrolyte of metal-supported solid oxide fuel cells

Authors	Chang-Sing Hwang, Te-Jung Hwang, Chun-Huang Tsai, Chun-Liang Chang, Sheng-Fu Yang, Ming-Hsiu Wu, Cheng-Yun Fu
Source	Ceramics International Volume: 43, Issue: 1, Pages: S591-S597 Time of Publication: 2017
Abstract	Four nickel-iron metal-supported solid oxide fuel cells with a diameter of 2.4 cm and a cathode active area of 1.76 cm2 are fabricated by atmospheric plasma spraying (APS) and heat-treated in air at 850 °C and 500 g cm−2 pressure for 4 h. These cells with the same functional layer materials have electrolyte layers produced by different APS torch powers, but the APS fabrication parameters for other functional layers of these cells are kept the same. XRD data show that there is a LaSrGaO4 impurity phase in the prepared dense LSGM electrolyte produced at 54 kW torch power. According to experimental data on the current-voltage-power and AC impedance measurements at temperatures ranging from 550 to 800 °C, the cell with dense LSGM electrolyte produced at 52 kW torch power has the best power performance and the lowest electrolyte resistance and the corresponding delivered power densities at 0.7 V for 550, 600, 650, 700, 750 and 800 °C temperatures are 0.147, 0.271, 0.426, 0.585, 0.716 and 0.796 W cm−2, respectively.
Keywords	Metal-supported, Solid oxide fuel cell, Atmospheric plasma spraying, LSGM electrolyte
Remark	Link

ID=402

The Effect of Metallic Co-Coating Thickness on Ferritic Stainless Steels Intended for Use as Interconnect Material in Intermediate Temperature Solid Oxide Fuel Cells

Authors	Hannes Falk-Windisch, Julien Claquesin, Jan-Erik Svensson, Jan Froitzheim
Source	Oxidation of Metals Pages: 1–18 Time of Publication: 2017
Abstract	The effect of metallic Co-coating thickness on ferritic stainless steels is investigated. This material is suggested to be used as interconnect material in intermediate temperature solid oxide fuel cells. Uncoated, 200-, 600-, 1000-, and 1500-nm Co-coated Sanergy HT is isothermally exposed for up to 500 h in air at 650 °C. Mass gain is recorded to follow oxidation kinetics, and area-specific resistance (ASR) measurements are conducted on samples exposed for 168 and 500 h. The microstructure of the thermally grown oxide scales is characterized utilizing scanning electron microscopy and energy-dispersive X-ray analysis on broad ion beam-milled cross sections. A clear increase in ASR as a function of Co-coating thickness is observed. However, the increase in ASR, as an effect of a thicker Co-coating, is correlated with thicker (Cr,Fe)2O3 scales formed on these materials and not to an increase in Co spinel top layer thickness.
Keywords	Solid oxide fuel cell, Interconnect, Coating, Area-specific resistance, Corrosion
Remark	DOI 10.1007/s11085-017-9782-9 Link

ID=394

Magnetron-sputtered La0.6Sr0.4Co0.2Fe0.8O3 nanocomposite interlayer for solid oxide fuel cells

Authors	A. A. Solovyev, I. V. Ionov, A. V. Shipilova, A. N. Kovalchuk, M. S. Syrtanov
Source	Journal of Nanoparticle Research Time of Publication: 2017
Abstract	A thin layer of a La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) is deposited between the electrolyte and the La0.6Sr0.4Co0.2Fe0.8O3/Ce0.9Gd0.1O2 (LSCF/CGO) cathode layer of a solid oxide fuel cell (SOFC) by pulsed magnetron sputtering using an oxide target of LSCF. The films were completely dense and well adherent to the substrate. The effects of annealing in temperature range from 200 to 1000 °C on the crystalline structure of the LSCF films have been studied. The films of nominal thickness, 250–500 nm, are crystalline when annealed at temperatures above 600 °C. The crystalline structure, surface topology, and morphology of the films were determined using X-ray diffraction (XRD), atomic force microscopy (AFM), and scanning electron microscopy (SEM), respectively. To study the electrochemical characteristics of the deposited-film, solid oxide fuel cells using 325-nm LSCF films as interlayer between the electrolyte and the cathode have been fabricated. The LSCF interlayer improves the overall performance of the SOFC by increasing the interfacial area between the electrolyte and cathode. The electrolyte-supported cells with the interlayer have 30% greater, overall power output compared to that achieved with the cells without interlayer. The LSCF interlayer could also act as a transition layer that improves adhesion and relieves both thermal stress and lattice strain between the cathode and the electrolyte. Our results demonstrate that pulsed magnetron sputtering provides a low-temperature synthesis route for realizing ultrathin nanocrystalline LSCF film layers for intermediate- or low-temperature solid oxide fuel cells.
Keywords	(La,Sr)(Co,Fe)O3 Magnetron sputtering Nanocomposite Interlayer Solid oxide fuel cells Nanostructured thin films Energy conversion
Remark	DOI: 10.1007/s11051-017-3791-0 Link

ID=392

Status report on high temperature fuel cells in Poland – Recent advances and achievements

Authors	J. Molenda, J. Kupecki, R. Baron, M. Blesznowski, G. Brus, T. Brylewski, M. Bucko, J. Chmielowiec, K. Cwieka, M. Gazda, A. Gil, P. Jasinski, Z. Jaworski, J. Karczewski, M. Kawalec, R. Kluczowski, M. Krauz, F. Krok, B. Lukasik, M. Malys, A. Mazur, A. Miele
Source	International Journal of Hydrogen Energy Volume: 42, Issue: 7, Pages: 4366–4403 Time of Publication: 2017
Abstract	The paper presents recent advances in Poland in the field of high temperature fuel cells. The achievements in the materials development, manufacturing of advanced cells, new fabrication techniques, modified electrodes and electrolytes and applications are presented. The work of the Polish teams active in the field of solid oxide fuel cells (SOFC) and molten carbonate fuel cell (MCFC) is presented and discussed. The review is oriented towards presenting key achievements in the technology at the scale from microstructure up to a complete power system based on electrochemical fuel oxidation. National efforts are covering wide range of aspects both in the fundamental research and the applied research. The review present the areas of (i) novel materials for SOFC including ZrO2-based electrolytes, CeO2-based electrolytes, Bi2O3 based electrolytes and proton conducting electrolytes, (ii) cathode materials including thermal shock resistant composite cathode material and silver-containing composites, (iii) anode materials, (iv) metallic interconnects for SOFC, (v) novel fabrication techniques, (vi) pilot scale SOFC, including electrolyte supported SOFC (ES-SOFC) and anode supported SOFC (AS-SOFC), (vii) metallic supported SOFC (MS-SOFC), (viii) direct carbon SOFC (DC-SOFC), (ix) selected application of SOFC, (x) advances in MCFC and their applications, (xi) advances in numerical methods for simulation and optimization of electrochemical systems.
Keywords	SOFC; MCFC; Experiments; Simulations; Fabrication techniques
Remark	https://doi.org/10.1016/j.ijhydene.2016.12.087 Link

ID=388

Co- and Ce/Co-coated ferritic stainless steel as interconnect material for Intermediate Temperature Solid Oxide Fuel Cells

Authors	Hannes Falk-Windisch, , Julien Claquesin, Mohammad Sattari, Jan-Erik Svensson, Jan Froitzheim
Source	Journal of Power Sources Volume: 343, Pages: 1-10 Time of Publication: 2017
Abstract	Chromium species volatilization, oxide scale growth, and electrical scale resistance were studied at 650 and 750 °C for thin metallic Co- and Ce/Co-coated steels intended to be utilized as the interconnect material in Intermediate Temperature Solid Oxide Fuel Cells (IT-SOFC). Mass gain was recorded to follow oxidation kinetics, chromium evaporation was measured using the denuder technique and Area Specific Resistance (ASR) measurements were carried out on 500 h pre-exposed samples. The microstructure of thermally grown oxide scales was characterized using Scanning Electron Microscopy (SEM), Scanning Transmission Electron Microscopy (STEM), and Energy Dispersive X-Ray Analysis (EDX). The findings of this study show that a decrease in temperature not only leads to thinner oxide scales and less Cr vaporization but also to a significant change in the chemical composition of the oxide scale. Very low ASR values (below 10 mΩ cm2) were measured for both Co- and Ce/Co-coated steel at 650 and 750 °C, indicating that the observed change in the chemical composition of the Co spinel does not have any noticeable influence on the ASR. Instead it is suggested that the Cr2O3 scale is expected to be the main contributor to the ASR, even at temperatures as low as 650 °C.
Keywords	Interconnect; Solid oxide fuel cell; Corrosion; Cr vaporization; Area specific resistance; Coating
Remark	http://dx.doi.org/10.1016/j.jpowsour.2017.01.045 Link

ID=387

Characterization of laser-processed thin ceramic membranes for electrolyte-supported solid oxide fuel cells

Authors
Source	International Journal of Hydrogen Energy Time of Publication: 2017
Abstract	By laser machining we have prepared thin and self-supported yttria stabilized zirconia (YSZ) electrolytes that can be used in electrolyte-supported solid oxide fuel cells for reducing the operation temperature. The membranes, which are supported by thicker areas of the same material, have an active area of ∼20 μm in thickness and up to 8 mm in diameter. Buckling limits the maximum size of the thin areas to below 1 mm, the overall effective active area being formed by multiple thin areas bounded by ribs. Electron Backscattering Diffraction experiments determined that there are not significant strains inside the membranes and that the heat-affected zone is confined to a shallow layer of ∼1–2 μm. The bending strength of the membranes decreases by ∼26% as a result of the surface microcracking produced by the laser machining. The membranes have a roughness of ∼2.5 μm and are coated by a layer of nanoparticles produced by the laser ablation. This coating and small roughness is not detrimental for the cathodic polarization of the cells. Conversely, the cathode polarization resistance decreases ∼5% in the 650–850 °C temperature range.
Keywords	SOFC; Solid electrolytes; Laser machining; Self-supporting ceramic membranes
Remark	http://dx.doi.org/10.1016/j.ijhydene.2016.12.112 Link

ID=385

The structural and electrical properties of samarium doped ceria films formed by e-beam deposition technique

Authors	Darius Virbukas, Giedrius Laukaitis
Source	Solid State Ionics Time of Publication: 2016
Abstract	Sm2O3-doped CeO2 (Sm0.15Ce0.85O1.925, SDC) thin films were formed by e-beam evaporation method. Thin films were formed evaporating micro powders (particle size varied from 0.3 to 0.5 μm). The influence of deposition rate on formed thin film structures and surface morphology were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersion spectrometry (EDS), and atomic force microscopy (AFM). The deposition rate of formed SDC thin films was changed from 2 to 16 Å/s. The electrical properties were investigated as a function of frequency (0.1–106 Hz) at different temperatures (473–873 K). The formed SDC thin ceramic films repeat the crystallographic orientation of the initial powders using different substrates and different deposition rate. It was determined that crystallites size and samarium concentration are decreasing by increasing the deposition rate. The crystallites size decreased from 17.0 nm to 10.4 nm when SDC thin films were deposited on Alloy 600 (Fe-Ni-Cr), and decreased from 13.7 nm to 8.9 nm when were used optical quartz substrate. The best ionic conductivity σtot = 1.66 Sm− 1 at 873 K temperature, activation energy ΔEa = 0.87 eV (σg = 1.66 Sm− 1, σgb = 1.66 Sm− 1) was achieved when 2 Å/s deposition rate was used. The grain size (in the formed SDC thin films) was ~ 83 nm in this case.
Keywords	Electron beam deposition; Samarium doped ceria oxide (SDC); Solid oxide fuel cells (SOFC); Ionic conductivity
Remark	http://dx.doi.org/10.1016/j.ssi.2016.12.003 Link

ID=378

Magnetron-Sputtered YSZ and CGO Electrolytes for SOFC

Authors	A.A. Solovyev, A.V. Shipilova, I.V. Ionov, A.N. Kovalchuk, S.V. Rabotkin, and V.O. Oskirko
Source	Journal of Electronic Materials Volume: 45, Issue: 8, Pages: 3921-3928 Time of Publication: 2016
	Solid oxide fuel cell, CGO, YSZ, bilayer electrolyte, magnetron sputtering, pulse electron-beam treatment
Remark	Link

ID=374

Evaluation of La0.75Sr0.25Cr0.5Mn0.5O3 protective coating on ferritic stainless steel interconnect for SOFC application

Authors	R.K. Lenka, P.K. Patro, Jyothi Sharma, T. Mahata, P.K. Sinha
Source	International Journal of Hydrogen Energy Time of Publication: 2016
Abstract	Ferritic stainless steel (SS) interconnect used for intermediate temperature solid oxide fuel cell has issues associated with the growth of oxide scale on the surface and evaporation of chromium species to the cathode leading to increase in polarization resistance and hence, overall cell resistance. Protective coating is essentially applied over the SS surface to restrict the above phenomena. In the present investigation, strontium doped lanthanum manganese chromite (LSCM) of composition La0.75Sr0.25Cr0.5Mn0.5O3 has been explored as a possible protective coating material on ferritic SS interconnect surface. For this application, fine LSCM powder was synthesized by solution polymerization method. Terpineol based slurry of LSCM was formulated and used for coating on ferritic SS surface by screen printing. LSCM coated ferritic SS was exposed to moist oxygen at 800 °C for 300 h and area specific resistance (ASR) of the coating was found to be as low as 2.0 mΩ cm2 after exposure. Microstructure of LSCM coating and the chromium oxide film was investigated using SEM and EDS. The results indicate that LSCM can form an effective protective coating on ferritic stainless steel for SOFC interconnect application.
Keywords	Interconnect; Protective coating; LSCM; SOFC
Remark	http://dx.doi.org/10.1016/j.ijhydene.2016.08.143 Link

ID=373

Solid oxide carbonate composite fuel cells: Size effect on percolation

Authors
Source	International Journal of Hydrogen Energy Time of Publication: 2016
Abstract	In the studies of solid oxide carbonate composite fuel cell, percolation behaviour of the two phases was investigated as a function of particle size of the oxide phase. The ratio of amount of samarium doped ceria (SDC; Sm0.2Ce0.8O) to Na2CO3 was varied to determine an optimum ionic conductivity as function of oxide particle size. The roles of both phases in the composite electrolyte were investigated. SDC particles were mixed in different amounts of Na2CO3 to obtain composites with carbonate ratios from 1 wt% to 50 wt%. Micro-structural investigations showed that Na2CO3 phase served as the matrix in the micro-structure gluing the oxide particles together. The lowest and the highest carbonate ratios caused low conductivities in the composite as in these samples the 3D connectivity of both phases were disrupted. Low conductivity at both ends of the mixture composition could be interpreted as none of the components of the composite dominated the ionic conductivity. The highest conductivity was obtained at 10 wt% Na2CO3 amount in the composite electrolyte when nano-sized SDC (5–10 nm) oxide powders were used. Two different particle sizes of SDC powders were used to show that the optimum phase ratio, i.e. percolation of both phases, is function of particle size as well. The conductivity in the composite showed percolation behaviour with respect to the two constituent phases.
Keywords	Composite electrolyte; SOFC; Interface; Percolation; Carbonate; Impedance
Remark	http://dx.doi.org/10.1016/j.ijhydene.2016.07.208, in press Link

ID=370

Comparison of characteristics of solid oxide fuel cells with YSZ and CGO film solid electrolytes formed using magnetron sputtering technique

Authors	A. A. Solov’ev, A. V. Shipilova, A. N. Koval’chuk, I. V. Ionov, S. V. Rabotkin
Source	Russian Journal of Electrochemistry Volume: 52, Issue: 7, Pages: 662–668 Time of Publication: 2016
Abstract	The work describes the methods of manufacturing single cells of solid oxide fuel cell (SOFC) with thin–film YSZ and CGO electrolytes and also with the bilayer YSZ/CGO electrolyte. Formation of YSZ and CGO films on the supporting NiO–YSZ anode of SOFC was carried out using the combined electron–ionic–plasma deposition technique. The microstructure and phase composition of the formed coatings are studied and also comparative analysis of electrochemical characteristics of single fuel cells with different electrolytes is performed. It is shown that the maximum power density of 1.35 W/cm2 at the temperature of 800°C is obtained for the cell with bilayer YSZ/CGO electrolyte. However, the highest performance at lower working temperatures (650–700°C) is characteristic for the fuel cell with single–layer CGO electrolyte; its power density is 600–650 mW/cm2.
Keywords	Solid oxide fuel cell, CGO, YSZ, bilayer electrolyte, magnetron sputtering, pulsed electron–beam treatment
Remark	DOI: 10.1134/S102319351607017X Link

ID=365

Leaching effect in gadolinia-doped ceria aqueous suspensions for ceramic processes

Authors	A. Caldarelli, E. Mercadelli, S. Presto, M. Viviani, A. Sanson
Source	Journal of Power Sources Volume: 326, Issue: 15, Pages: 70–77 Time of Publication: 2016
Abstract	Gadolinium doped ceria (CGO) is a commonly used electrolytic material for Solid Oxide Fuel Cells (SOFCs) and for this reason different shaping methods for its deposition are reported in literature. Most of these processes are based on the use of organic-based CGO suspensions, but water-based processes are acquiring increasingly interest for their economical and environmental friendly properties. In this paper we reported how the components of water-based suspension and some unexpected process parameters can deeply affect the functional properties of the final powder. In particular, we observed that CGO powders are strongly affected by ionic leaching induced by furoic acid used as dispersant: the extent of this leaching was related to the dispersant concentration and suspension’s ball-milling-time; the phenomenon was confirmed by ICP-AES analyses on suspensions surnatant. Most importantly, ionic leaching affected the electrical properties of CGO: leached powder showed a higher ionic conductivity as a consequence of a partial removal of Gd ions at the grain boundaries. This work is therefore pointing out that when considering water-based suspensions, it is extremely important to carefully consider all the process parameters, including the organic components of the ceramic suspension, as these could lead to unexpected effects on the properties of the powder, affecting the performance of the final shaped material.
Keywords	Gadolinium doped ceria; Water-based suspensions; Furoic acid; Ionic leaching; Electrical conductivity
Remark	doi:10.1016/j.jpowsour.2016.06.069 Link

ID=361

Synthesis, characterization and performance of robust poison-resistant ultrathin film yttria stabilized zirconia – nickel anodes for application in solid electrolyte fuel cells

Authors
Source	Journal of Power Sources Volume: 324, Pages: 679–686 Time of Publication: 2016
Abstract	We report on the synthesis of undoped ∼5 μm YSZ-Ni porous thin films prepared by reactive pulsed DC magnetron sputtering at an oblique angle of incidence. Pre-calcination of the amorphous unmodified precursor layers followed by reduction produces a film consisting of uniformly distributed tilted columnar aggregates having extensive three-phase boundaries and favorable gas diffusion characteristics. Similarly prepared films doped with 1.2 at.% Au are also porous and contain highly dispersed gold present as Ni-Au alloy particles whose surfaces are strongly enriched with Au. With hydrogen as fuel, the performance of the undoped thin film anodes is comparable to that of 10–20 times thicker typical commercial anodes. With a 1:1 steam/carbon feed, the un-doped anode cell current rapidly falls to zero after 60 h. In striking contrast, the initial performance of the Au-doped anode is much higher and remains unaffected after 170 h. Under deliberately harsh conditions the performance of the Au-doped anodes decreases progressively, almost certainly due to carbon deposition. Even so, the cell maintains some activity after 3 days operation in dramatic contrast with the un-doped anode, which stops working after only three hours of use. The implications and possible practical application of these findings are discussed.
Keywords	Magnetron sputtering; Oblique angle deposition; Thin film anodes; Carbon-tolerant; SOFC
Remark	doi:10.1016/j.jpowsour.2016.05.124 Link

ID=357

Effect of Nd-deficiency on electrochemical properties of NdBaCo2O6−δ cathode for intermediate-temperature solid oxide fuel cells

Authors
Source	International Journal of Hydrogen Energy Volume: 41, Issue: 24, Pages: 10228–10238 Time of Publication: 2016
Abstract	Nd1−xBaCo2O6−δ (N1−xBCO) is evaluated as cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The effects of Nd-deficiency on the crystal structure, thermal expansion behavior, electrical conductivity and electrochemical performance are studied. N1−xBCO oxides crystallize in the orthorhombic symmetry with Pmmm space group. A good chemical compatibility between N1−xBCO and CGO electrolyte is found at 1100 °C in air. Introducing Nd-deficiency promotes the formation of oxygen vacancy, and significantly improves the electrochemical performance of N1−xBCO cathodes. The lowest area specific resistance (ASR) value of 0.043 Ω cm2 is obtained on the N0.96BCO cathode at 700 °C in air. The rate limiting step for electrochemical oxygen reduction reaction (ORR) is charge transfer process at the interface. The power output of the electrolyte supported cell Ni-CGO/CGO/N0.96BCO reaches 0.6 W cm−2 at 700 °C.
Keywords	Solid oxide fuel cell; Double perovskite; Nd-deficiency; Cathode; Electrode reaction
Remark	doi:10.1016/j.ijhydene.2016.04.248 Link

ID=355

Influence of cathode functional layer composition on electrochemical performance of solid oxide fuel cells

Authors
Source	Journal of Solid State Electrochemistry Time of Publication: 2016
Abstract	In this work, anode-supported solid oxide fuel cells (SOFC) were tested with a yttria-stabilized zirconia (YSZ) (8 mol% Y2O3-ZrO2)/gadolinium-doped ceria (GDC) (Ce0.9Gd 0.1O1.95) bilayer electrolyte and two lanthanum strontium cobalt ferrite (LSCF) composition as functional cathode layer: La0.6Sr0.4Co0.8Fe0.2O3-δ (LSCF 1) and La0.60Sr0.40Co0.2Fe0.8O3-δ (LSCF 2). The functional cathode layers were made of 50 % (w/w) LSCF and 50 % (w/w) GDC. Microstructural characterization was performed by scanning electron microscopy and X-ray diffraction. Electrochemical impedance spectroscopy (EIS) and power measurements were performed under oxygen and hydrogen atmospheres. The microscopy studies showed that the LSCF 2 functional layer is more uniform and adherent to the electrolyte and the cathode collector than the LSCF 1 functional layer, which has cracks, chips, and lower adhesion. The use of the LSCF 2 layer allowed an approximately 25-fold reduction in ohmic resistance (0.06 Ω cm−2) compared with the LSCF 1 layer (1.5 Ω cm−2). The power measurements showed a considerable increase in the power cell using LSCF 2 (approximately 420 mW cm−2) compared with the power cell using LSCF 1 (approximately 180 mW cm−2).
Keywords	SOFC, LSCF, Interface, Electrochemical performance, Cathode, Functional layer
Remark	First Online: 20 May 2016. DOI: 10.1007/s10008-016-3241-4 Link

ID=353

Electrochemical Property Assessment of Pr2CuO4 Submicrofiber Cathode for Intermediate-Temperature Solid Oxide Fuel Cells

Authors
Source	Journal of Electrochemical Energy Conversion and Storage Volume: 13, Issue: 1, Pages: 011006 Time of Publication: 2016
Abstract	The Pr2CuO4 (PCO) submicrofiber precursors are prepared by electrospinning technique and the thermo-decomposition procedures are characterized by thermal gravity (TG), X-ray diffraction (XRD), Fourier transform infrared spectoscopy (FT-IR), and scanning electron microscopy (SEM), respectively. The fibrous PCO material was formed by sintering the precursors at 900 °C for 5 hrs. The highly porous PCO submicrofiber cathode forms good contact with the Ce0.9Gd0.1O1.95 (CGO) electrolyte after heat-treated at 900 °C for 2 hrs. The performance of PCO submicrofiber cathode is comparably studied with the powder counterpart at various temperatures. The porous microstructure of the submicrofiber cathode effectively increases the three-phase boundary (TPB), which promotes the surface oxygen diffusion and/or adsorption process on the cathode. The PCO submicrofiber cathode exhibits an area specific resistance (ASR) of 0.38 Ω cm2 at 700 °C in air, which is 30% less than the PCO powder cathode. The charge transfer process is the rate limiting step of the oxygen reduction reaction (ORR) on the submicrofiber cathode. The maximum power densities of the electrolyte-support single cell PCO\|CGO\|NiO-CGO reach 149 and 74.5 mW cm−2 at 800 and 700 °C, respectively. The preliminary results indicate that the PCO submicrofiber can be considered as potential cathode for intermediate temperature solid fuel cells (IT-SOFCs).
Remark	doi: 10.1115/1.4033526 Link

ID=351

Magnetron-Sputtered YSZ and CGO Electrolytes for SOFC

Authors	A. A. Solovyev , A. V. Shipilova, I. V. Ionov, A. N. Kovalchuk, S. V. Rabotkin, V. O. Oskirko
Source	Journal of Electronic Materials Time of Publication: 2016
Abstract	Reactive magnetron sputtering has been used for deposition of yttria-stabilized ZrO2 (YSZ) and gadolinium-doped CeO2 (CGO) layers on NiO-YSZ commercial anodes for solid oxide fuel cells. To increase the deposition rate and improve the quality of the sputtered thin oxide films, asymmetric bipolar pulse magnetron sputtering was applied. Three types of anode-supported cells, with single-layer YSZ or CGO and YSZ/CGO bilayer electrolyte, were prepared and investigated. Optimal thickness of oxide layers was determined experimentally. Based on the electrochemical characteristics of the cells, it is shown that, at lower operating temperatures of 650°C to 700°C, the cells with single-layer CGO electrolyte are most effective. The power density of these fuel cells exceeds that of the cell based on YSZ single-layer electrolyte at the same temperature. Power densities of 650 mW cm−2 and 500 mW cm−2 at 700°C were demonstrated by cells with single-layer YSZ and CGO electrolyte, respectively. Significantly enhanced maximum power density was achieved in a bilayer-electrolyte single cell, as compared with cells with a single electrolyte layer. Maximum power density of 1.25 W cm−2 at 800°C and 1 W cm−2 at 750°C under voltage of 0.7 V were achieved for the YSZ/CGO bilayer electrolyte cell with YSZ and CGO thickness of about 4 μm and 1.5 μm, respectively. This signifies that the YSZ thin film serves as a blocking layer to prevent electrical current leakage in the CGO layer, leading to the overall enhanced performance. This performance is comparable to the state of the art for cells based on YSZ/CGO bilayer electrolyte.
Keywords	Solid oxide fuel cell CGO YSZ bilayer electrolyte magnetron sputtering pulse electron-beam treatment
Remark	Link

ID=350

Characteristics of Cu and Mo-doped Ca3Co4O9−δ cathode materials for use in solid oxide fuel cells

Authors	Sea-Fue Wang, Yung-Fu Hsu, Jing-Han Chang, Soofin Cheng, Hsi-Chuan Lu
Source	Ceramics International Time of Publication: 2016
Abstract	In this study, Cu and Mo ions were doped in Ca3Co4O9−δ to improve the electrical conductivity and electrochemical behavior of Ca3Co4O9−δ ceramic and the performance of a solid oxide fuel cell (SOFC) single cell based on NiO-SDC/SDC/doped Ca3Co4O9−δ-SDC were examined. Cu substitution in the monoclinic Ca3Co4O9−δ ceramic effectively enhanced the densification, slightly increased the grain size, and triggered the formation of some Ca3Co2O6; however, no second phase was found in porous Mo-doped Ca3Co4O9−δ ceramics even when the sintering temperature reached 1050 °C. Substitution of Cu ions caused slight increase in the Co3+ and Co4+ contents and decrease in the Co2+ content; however, doping with Mo ions showed the opposite trend. Doping the Ca3Co4O9−δ ceramic with a small amount of Cu or Mo increased its electrical conductivity. The maximum electrical conductivity measured was 218.8 S cm−1 for the Ca3Co3.9Cu0.1O9−δ ceramic at 800 °C. The Ca3Co3.9Cu0.1O9−δ ceramic with a coefficient of thermal expansion coefficient of 12.1×10−6 K−1 was chosen as the cathode to build SOFC single cells consisting of a 20 μm SDC electrolyte layer. Without optimizing the microstructure of the cathode or hermetically sealing the cell against the gas, a power density of 0.367 Wcm−2 at 750 °C was achieved, demonstrating that Cu-doped Ca3Co4O9−δ can be used as a potential cathode material for IT-SOFCs.
Keywords	Solid oxide fuel cell; Cathode; Impedance; Cell performance
Remark	In Press, doi:10.1016/j.ceramint.2016.04.037 Link

ID=349

Synthesis and characterization of robust, mesoporous electrodes for solid oxide fuel cells

Authors
Source	Journal of Materials Chemistry A Time of Publication: 2016
Abstract	The use of mesoporous electrodes in solid oxide cells would lead to a significant enhancement of the performance due to their high surface area and large number of active sites for electrochemical reactions. However, their application in real devices is still hindered by the potential instability of the mesostructure and morphology at high temperatures required for device fabrication and under severe conditions for high-current, long-term operation. Here we report our findings on the preparation and characterization of mesoporous electrodes based on ceria infiltrated with catalysts: an anode consisting of a Ce0.8Sm0.2O1.9 (SDC) scaffold infiltrated with Ni and a cathode consisting of an SDC scaffold infiltrated with Sm0.5Sr0.5CoO3−δ (SSC). In particular, a doped-zirconia electrolyte supported cell with a mesoporous Ni–SDC anode and a mesoporous SSC–SDC cathode demonstrates an excellent peak power density of 565 mW cm−2 at 750 °C (using humidified hydrogen as the fuel). More importantly, both mesoporous electrodes display remarkable stability, yielding a combined electrode virtual non-degradation for the last 500 hours of the test at a constant current density of 635 mA cm−2 at 750 °C, demonstrating the potential of these mesoporous materials as robust electrodes for solid oxide fuel cells or other high-temperature electrochemical energy storage and conversion devices.
Remark	DOI: 10.1039/C6TA00321D Link

ID=347

Structural study and proton conductivity in BaCe0.7Zr0.25−xYxZn0.05O3 (x = 0.05, 0.1, 0.15, 0.2 & 0.25)

Authors	Ahmed Afif, Nikdalila Radenahmad, Chee Ming Lim, Mohamad Iskandar Petra, Md. Aminul Islam, Seikh Mohammad Habibur Rahman, Sten Eriksson, Abul Kalam Azad
Source	International Journal of Hydrogen Energy Time of Publication: 2016
Abstract	Solid oxide fuel cell (SOFC) has been considered to generate power represented by conductivity. Zinc doped Barium Cerium Zirconium Yttrium oxide (BCZYZn) has been found to offer high protonic conductivity and high stability as being electrolyte for proton-conducting SOFCs. In this study, we report a new series of proton conducting materials, BaCe0.7Zr0.25−xYxZn0.05O3 (x = 0.05, 0.1, 0.15, 0.2 and 0.25). The materials were synthesized by solid state reaction route and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), thermal expansion, particle size and impedance spectroscopy (IS). Rietveld analysis of the XRD data reveal a cubic perovskite structure with Pm-3m space group up to composition x = 0.15. For x = 0.15 and 0.20, the materials have structural phase change to orthorhombic in the Pbnm space group. Scanning electron microscopy images show high density materials. Thermal expansion measurements show that the thermal expansion coefficient is in the range 10.0–11.0 × 10−6/°C. Impedance spectroscopy shows higher ionic conduction under wet condition compared to dry condition. Y content of 25% (BCZYZn25) exhibits highest conductivity of 1.84 × 10−2 S/cm in wet Argon. This study indicated that perovskite electrolyte BCZYZn is promising material for the next generation of intermediate temperature solid oxide fuel cells (IT-SOFCs).
Keywords	Proton conductor; Sinterability; Rietveld refinement; Conductivity; SOFC electrolyte
Remark	In Press, doi:10.1016/j.ijhydene.2016.02.135 Link

ID=337

Synthesis and properties of La0.05Ba0.95Ti1 −xMyO3 (M = Mn, Ce) as anode materials for solid oxide fuel cells

Authors
Source	Solid State Ionics Volume: 283, Pages: 21–29 Time of Publication: 2015
Abstract	Stoichiometric and sub-stoichiometric lanthanum barium titanates (LBT) of perovskite structure type, substituted or not with Mn and/or Ce at the Ti-site, were prepared by sol–gel route with heat treatment in air. All the compounds display a cubic Pm-3m symmetry, which remains stable in reducing atmosphere. Whereas Mn substitution highly promotes the reducibility of the material, the electrical and electrochemical performance of Mn-doped compounds is decreased with respect to non-doped sub-stoichiometric LBT. In contrast, the electrical conductivity and resistance polarization of Ce-substituted LBT are close to those of non-doped LBT and Ce-substituted LBT appears especially efficient in improving the catalytic properties for methane steam reforming and avoiding carbon formation.
Keywords	SOFC; Anode; Perovskite; Barium titanate; Impedance electrochemical spectroscopy; Methane steam reforming
Remark	doi:10.1016/j.ssi.2015.11.005 Link

ID=336

Molybdenum doped Pr0.5Ba0.5MnO3−δ (Mo-PBMO) double perovskite as a potential solid oxide fuel cell anode material

Authors	Yi-Fei Sun, Ya-Qian Zhang, Bin Hua, Yashar Behnamian, Jian Li, Shao-Hua Cui, Jian-Hui Lid, Jing-Li Luo
Source	Journal of Power Sources Volume: 301, Pages: 237–241 Time of Publication: 2016
Abstract	A layered Mo doped Pr0.5Ba0.5MnO3−δ (Mo-PBMO) double perovskite oxide was prepared by a modified sol–gel method and the properties of the fabricated material are characterized by various technologies. The results of X-ray diffraction (XRD), H2-temperature programmed reduction (H2-TPR), NH3-temperature programmed desorption (NH3-TPD), and thermogravimetric analysis (TGA) demonstrate that the treatment in reducing atmosphere at high temperature lead to a significant phase transformation of the material to a single cubic phase as well as with the Mo in multiple oxidized states. Such character leads to the production of large amount of oxygen deficiency with facilitated oxygen diffusion. The electrochemical performance tests of half-cell and single cell SOFCs exhibit the promoted effect of Mo on catalytic activity for the oxidation of H2 and CH4, indicating that Mo-PBMO could serve as an anode material candidate for SOFCs.
Keywords	Mo; Pr0.5Ba0.5MnO3−δ; Double perovskite; Anode; SOFC
Remark	doi:10.1016/j.jpowsour.2015.09.127 Link

ID=334

Effect of Cerium on the Electrical Properties of a Cobalt Conversion Coating for Solid Oxide Fuel Cell Interconnects – A Study Using Impedance Spectroscopy

Authors	Jan Gustav Grolig, Jan Froitzheim, Jan-Erik Svensson
Source	Electrochimica Acta Volume: 184, Pages: 301–307 Time of Publication: 2015
Abstract	Coatings of metallic cobalt, which convert into a cobalt manganese spinel oxide are known to improve the properties of interconnects for solid oxide fuel cells (SOFCs). The addition of cerium to the cobalt coating further improves the corrosion properties of the material. For this study traditional four-point DC measurements at high temperatures were combined with impedance spectroscopy at low temperatures in order to investigate the effect of cerium on the electrical properties of a cobalt conversion coating. It was found that combination-coatings of cerium and cobalt exhibit superior electrical properties compared to pure cobalt coatings. Cerium slows down the growth of chromia and prevents the outward diffusion of iron into the cobalt spinel layer. Both effects are beneficial for the electrical properties of the interconnect. Impedance spectroscopy measurements revealed that even after more than 3000 h of exposure the outer cobalt manganese spinel layer still has a higher electrical conductivity when cerium was present.
Remark	doi:10.1016/j.electacta.2015.10.111 Link

ID=325

Enhanced Carbon Deposition Tolerance of SOFC Anodes Under Triode Operation

Authors	Ioanna Petrakopoulou, Dimitrios Tsiplakides, Stella Balomenou
Source	Topics in Catalysis Volume: 58, Issue: 18, Pages: 1303-1310 Time of Publication: 2015
Abstract	The triode fuel cell design and operation concept was applied as an alternative means for controlling and enhancing the carbon tolerance of state-of-the-art solid oxide fuel cell (SOFC) anodes. The triode cell configuration entails the introduction of a third electrode in addition to the anode and cathode, driven by an auxiliary circuit which is run in electrolytic mode. In this way the cell is forced to operate at controlled potential differences that are inaccessible under standard operation, and thus introduces a controllable variable into fuel cell operation. In the present study, the effectiveness of the triode approach was evaluated for the in situ control of the rate of carbon deposition in commercial multilayer NiO–GDC and NiO–YSZ SOFC anodes. The study involved typical and triode operation of SOFC button cells under CH4 steam reforming conditions, and it was found that the application of a small electrolytic current under triode operation resulted in significantly less carbon built-up on the anode compared to the standard SOFC operation.
Keywords	SOFC Triode fuel cell operation, Anode degradation, Carbon formation, CH4 steam reforming
Remark	Link

ID=324

Development of a Coking-Resistant NiSn Anode for the Direct Methane SOFC

Authors	N. Bogolowski, B. Iwanschitz and J.-F. Drillet
Source	Fuel Cells Volume: 15, Issue: 5, Pages: 711–717
Abstract	The present work reports on the development of a coking-resistant NiSn-based membrane electrode assembly (MEA) for internal CH4 reforming in solid oxide fuel cells (SOFCs). Catalyst powder was prepared in a centrifugal casting oven by melting stoichiometric amounts of Ni and Sn under vacuum. The formation of Ni3Sn2 intermetallic phase was confirmed by XRD analysis. Catalytic activity for CH4 reforming and stability of the NiSn powder were first evaluated in a quartz glass reactor for 4 h at 600–1,000 °C. The main reaction products H2 and CO were detected by gas chromatography while no carbon formation was detected during the experiments. Then, 3YSZ electrolyte-supported MEAs were fabricated with a Ni3Sn2/YSZ anode and LSM/YSZ cathode and characterized under SOFC conditions. The MEA showed an excellent stability under CH4 atmosphere (3% H2O) at 850 °C over more than 650 h. No substantial decrease in cell potential was observed during this period.
Keywords	Anode Material;Intermetallic Phase;Internal Reforming;Methane;Nickel-Tin Alloy;Ni3Sn2;SOFC;Solid Oxide Fuel Cell
Remark	DOI: 10.1002/fuce.201400187 Link

ID=322

Copper Iron Conversion Coating for Solid Oxide Fuel Cell Interconnects

Authors	Jan Gustav Grolig, , Patrik Alnegren, Jan Froitzheim, Jan-Erik Svensson
Source	Journal of Power Sources Volume: 297, Pages: 534–539 Time of Publication: 2015
Abstract	A conversion coating of iron and copper was investigated with the purpose of increasing the performance of Sanergy HT as a potential SOFC interconnect material. Samples were exposed to a simulated cathode atmosphere (air, 3 % H2O) for durations of up to 1000 h at 850 °C. Their performance in terms of corrosion, chromium evaporation and electrical resistance (ASR) was monitored and compared to uncoated and cobalt-coated Sanergy HT samples. The copper iron coating had no negative effects on corrosion protection and decreased chromium evaporation by about 80%. An Area Specific Resistance (ASR) of 10 mΩcm2 was reached after 1000 h of exposure. Scanning Electron Microscopy revealed well adherent oxide layers comprised of an inner chromia layer and an outer spinel oxide layer.
Keywords	Interconnect; Corrosion; Chromium volatilization; Sanergy HT; SOFC; Area specific resistance
Remark	doi:10.1016/j.jpowsour.2015.06.139 Link

ID=318

EuBaCo2O5+δ-Ce0.9Gd0.1O2−δ composite cathodes for intermediate-temperature solid oxide fuel cells: high electrochemical performance and oxygen reduction kinetics

Authors	Zhan Shi, Tian Xia, Fuchang Meng, Jingping Wang, Shengming Wu, Jie Lian, Hui Zhao, Chunbo Xu
Source	Electrochimica Acta Volume: 174, Pages: 608–614 Time of Publication: 2015
Abstract	The characteristics and electrochemical performance of double perovskite EuBaCo2O5+δ (EBCO) have been investigated as a composite cathode for intermediate-temperature solid oxide fuel cells (IT-SOFCs). The thermal expansion coefficients can be effectively reduced in the case of EBCO-Ce0.9Gd0.1O2−δ (CGO) composite cathodes. No chemical reactions between EBCO cathode and CGO electrolyte are observed after sintering at 1000 °C for 24 h. The maximum electrical conductivities of EBCO-CGO materials reach 28-77 S cm−1 with the change of CGO weight ratio from 40 wt. % to 5 wt. %. Among all these components, the EBCO-10 wt. % CGO (EBCO-10CGO) composite cathode gives the lowest area-specific resistance of 0.055 and 0.26 Ω cm2 in air at 700 and 600 °C, respectively. The maximum power density of Ni-CGO anode-supported single cell consisted of the EBCO-10CGO composite cathode and CGO electrolyte achieves 0.81 W cm−2 at 700 °C. These results indicate that the EBCO-10CGO composite materials can be used as a promising cathode candidate for IT-SOFCs. Furthermore, the rate-limiting steps for the oxygen reduction reaction at the EBCO-10CGO composite cathode interface are determined to be the charge transfer and dissociation of adsorbed molecule oxygen processes.
Keywords	Intermediate-temperature solid oxide fuel cells; cathode materials; electrochemical performance; oxygen reduction kinetics
Remark	doi:10.1016/j.electacta.2015.06.059 Link

ID=315

Gd- and Pr-based double perovskite cobaltites as oxygen electrodes for proton ceramic fuel cells and electrolyser cells

Authors
Source	Solid State Ionics Volume: 278, Pages: 120–132 Time of Publication: 2015
Abstract	Double perovskite oxides BaGd0.8La0.2Co2O6−δ (BGLC), BaGdCo1.8Fe0.2O6−δ (BGCF), BaPrCo2O6−δ (BPC) and BaPrCo1.4Fe0.6O6−δ (BPCF) were investigated as oxygen electrodes on mixed conducting BaZr0.7Ce0.2Y0.1O3 (BZCY72) electrolyte using impedance spectroscopy vs temperature, pO2, and pH2O. We propose and have applied a novel approach to extract and parameterise the charge transfer and diffusion impedances of the electrode reactions in a system comprising charge transport of protons, oxide ions, and electrons. Given by the properties of the BZCY72, transport of protons dominates at lower temperatures and high pH2O, oxide ions at higher temperatures, and electron holes increasingly at high temperatures and high pO2. The electrodes showed good performance, with the lowest total apparent polarisation resistance for BGLC/BZCY72 being 0.05 and 10 Ωcm2 at 650 and 350 °C, respectively. The low temperature rate limiting reaction step is a surface related process, involving protonic species, with an activation energy of approximately 50 kJ mol−1 for BGLC/BZCY72. The oxide ion transport taking over at higher temperatures exhibits a higher activation energy typical of SOFC cathodes. Thermogravimetric studies revealed that BGLC exhibits considerable protonation at 300–400 °C, which may be interpreted as hydration with an enthalpy of approximately –50 kJ mol−1. The resulting mixed proton electron conduction may explain its good performance as electrode on BZCY72.
Keywords	PCFC; PCEC; P-MIEC; Proton conductor; Mixed conductivity; Double perovskite
Remark	doi:10.1016/j.ssi.2015.05.014 Link

ID=313

Praseodymium-deficiency Pr0.94BaCo2O6-δ double perovskite: A promising high performance cathode material for intermediate-temperature solid oxide fuel cells

Authors	Fuchang Meng, Tian Xia, Jingping Wang, Zhan Shi, Hui Zhao
Source	Journal of Power Sources Volume: 239, Pages: 741–750 Time of Publication: 2015
Abstract	Praseodymium-deficiency Pr0.94BaCo2O6-δ (P0.94BCO) double perovskite has been evaluated as a cathode material for intermediate-temperature solid oxide fuel cells. X-ray diffraction pattern shows the orthorhombic structure with double lattice parameters from the primitive perovskite cell in Pmmm space group. P0.94BCO has a good chemical compatibility with Ce0.9Gd0.1O1.95 (CGO) electrolyte even at 1000 °C for 24 h. It is observed that the Pr-deficiency can introduce the extra oxygen vacancies in P0.94BCO, further enhancing its electrocatalytic activity for oxygen reduction reaction. P0.94BCO demonstrates the promising cathode performance as evidenced by low polarization are-specific resistance (ASR), e. g. 0.11 Ω cm2 and low cathodic overpotential e. g. −56 mV at a current density of −78 mA cm−2 at 600 °C in air. These features are comparable to those of the benchmark cathode Ba0.5Sr0.5Co0.8Fe0.2O3-δ. The fuel cell CGO-Ni\|CGO\|P0.94BCO presents the attractive peak power density of 1.05 W cm−2 at 600 °C. Furthermore, the oxygen reduction kinetics of P0.94BCO material is also investigated, and the rate-limiting steps for oxygen reduction reaction are determined.
Keywords	Intermediate-temperature solid oxide fuel cell; Cathode material; Double perovskite; Electrochemical performance; Oxygen reduction reaction
Remark	doi:10.1016/j.jpowsour.2015.06.007 Link

ID=312

Reduced long term electrical resistance in Ce/Co-coated ferritic stainless steel for solid oxide fuel cell metallic interconnects

Authors
Source	International Journal of Hydrogen Energy Volume: 40, Issue: 27, Pages: 8579–8585
Abstract	The present study is focused on the influence of selected coatings on a ferritic stainless steel (Sanergy HT™, Sandvik) on the evolution of the area specific resistance (ASR) as a function of time at high temperature. The samples are exposed in humidified air at 850 °C for up to 4200 h. It combines long-term ASR measurements with the thermogravimetric behavior and microstructural analysis of the cross sections by scanning electron microscopy. The results show that uncoated and Co-coated Sanergy HT™ exhibit similar oxidation kinetics and comparable ASRs, while a combined Ce/Co coating improves oxidation resistance and, consequently, reduces the ASR significantly. Other reports have earlier shown that Co- (and Ce/Co)-coated Sanergy HT™ reduces the evaporation of volatile chromium species. Overall, the study indicates that Ce/Co-coatings will render substantially improved performance for ferritic steel interconnects for solid oxide fuel cells.
Keywords	Metallic coating; SOFC; Interconnects; Stainless steel; Conductivity; ASR
Remark	doi:10.1016/j.ijhydene.2015.04.147 Link

ID=310

Triode operation for enhancing the performance of H2S-poisoned SOFCs operated under CH4–H2O mixtures

Authors	Foteini M. Sapountzi, Michail N. Tsampas, Chunhua Zhao, Antoinette Boreave, Laurence Retailleau, Dario Montinaro, Philippe Vernoux
Source	Solid State Ionics Volume: 277, Pages: 65–71 Time of Publication: 2015
Abstract	Performances of Solid Oxide Fuel Cells (SOFCs) were investigated in triode operation mode under methane steam reforming in the presence of H2S. Both the catalytic performances for methane steam reforming and the electrochemical properties for the electrochemical oxidation of hydrogen of a Ni/GDC anode drastically dropped in the presence of 1 ppm H2S. Poisoned catalytic sites are different from those for the hydrogen electrochemical oxidation. Triode operation, i.e. application of moderate negative currents between the anode and an auxiliary electrode, can improve electrochemical properties, as a result of a local production of H2 coming from H2O electrolysis. Some specific triode operations were found to achieve a thermodynamic efficiency close to the unity to avoid any energy overconsumption.
Keywords	SOFC; Triode operation; H2S poisoning; Ni/GDC anode
Remark	doi:10.1016/j.ssi.2015.05.003 Link

ID=309

High-temperature anion and proton conduction in RE3NbO7 (RE = La, Gd, Y, Yb, Lu) compounds

Authors
Source	Journal of the European Ceramic Society Volume: 35, Issue: 11, Pages: 3051–3061 Time of Publication: 2015
Abstract	The oxide-ion and proton conduction properties of RE3NbO7 (RE = La, Gd, Y, Yb, Lu) compounds were investigated. For the bigger rare-earth cation, i.e. La3+, the compound crystallises in a weberite-type structure and the oxide-ion conductivity is low owing to the lack of intrinsic oxygen vacancies. Consequently, the resultant proton incorporation and conductivity in La3NbO7 are also low. For small rare-earth cations, i.e. from Gd3+ to Lu3+ and for RE = Y, materials adopt a fluorite-like structure confirmed from X-ray powder diffraction. In this latter case, materials include intrinsic oxygen vacancies leading to a higher oxygen conductivity. For these compounds, a proton incorporation takes place at low temperature under wet conditions giving rise to proton conductivity. Nevertheless, both oxygen and proton conductivities are low in these materials, which can be explained by the ordering of oxygen vacancies observed by Transmission Electron Microscopy.
Keywords	Protonic ceramic fuel cell; Rare-earth niobate; Combustion synthesis; Fluorite-type structure; Electrical properties
Remark	doi:10.1016/j.jeurceramsoc.2015.04.014 Link

ID=302

Coated stainless steel 441 as interconnect material for solid oxide fuel cells: Evolution of electrical properties

Authors	Jan Gustav Grolig , Jan Froitzheim, Jan-Erik Svensson
Source	Journal of Power Sources Volume: 284, Pages: 321–327 Time of Publication: 2015
Abstract	AISI 441 coated with a double layer coating of 10 nm cerium (inner layer) and 630 nm cobalt was investigated and in addition the uncoated material was exposed for comparison. The main purpose of this investigation was the development of a suitable ASR characterization method. The material was exposed to a simulated cathode atmosphere of air with 3% water at 850 °C and the samples were exposed for up to 1500 h. We compared two methods of ASR measurements, an in-situ method where samples were measured with platinum electrodes for longer exposure times and an ex-situ method where pre-oxidized samples were measured for only very short measurement times. It was found that the ASR of ex-situ characterized samples could be linked to the mass gain and the electrical properties could be linked to the evolving microstructure during the different stages of exposure. Both the degradation of the electric performance and the oxygen uptake (mass gain) followed similar trends. After about 1500 h of exposure an ASR value of about 15 mΩcm2 was reached. The in-situ measured samples suffered from severe corrosion attack during measurement. After only 500 h of exposure already a value of 35 mΩcm2 was obtained.
Keywords	ASR; Interconnect; AISI 441; SOFC; Corrosion; Platinum
Remark	doi:10.1016/j.jpowsour.2015.03.029 Link

ID=299

Structure and conductivity of acceptor doped La2BaZnO5 and Nd2BaZnO5

Authors	Md. Khairul Hoque, Reidar Haugsrud, Christopher S. Knee
Source	Solid State Ionics Volume: 272, Pages: 160–165 Time of Publication: 2015
Abstract	The effect of calcium substitution on the structure and electrical conductivity of Ln2 − xCaxBaZnO5 − δ, Ln = La and Nd, has been studied. Differing trends with respect to dependence of the unit cell volume were observed as a function of Ca substitution. For both series of materials the limit of Ca substitution was estimated to be x ≈ 0.2. The electrical conductivity was studied in the temperature range of 1000–350 °C using electrochemical impedance spectroscopy in argon and oxygen atmospheres and via isotherms between 400 and 1000 °C as function of oxygen pressure and the water vapour pressure. A marked increase in conductivity of approx. two orders of magnitude was explained by the presence of oxygen vacancies in the calcium doped samples. At pO2 < 10− 12 atm the x = 0.15 materials are predominantly oxygen ion conductors, and La1.85Ca0.15BaZnO5 − δ displays a peak conductivity of 0.002 S cm− 1 at 1000 °C. The materials display a rise in conductivity in oxidizing conditions, indicating a significant p-type contribution.
Keywords	Oxide ion conductor; Mixed conductor; Synthesis; Impedance spectroscopy; SOFC
Remark	doi:10.1016/j.ssi.2015.02.001 Link

ID=297

Solid oxide fuel cells with (La,Sr)(Ga,Mg)O3-δ electrolyte film deposited by radio-frequency magnetron sputtering

Authors	Sea-Fue Wang, His-Chuan Lu, Yung-Fu Hsu, Yi-Xuan Hu
Source	Journal of Power Sources Volume: 281, Pages: 258–264 Time of Publication: 2015
Abstract	In this study, solid oxide fuel cells (SOFCs) containing a high quality La0.9Sr0.1Ga0.8Mg0.2O3-δ (LSGM) film deposited on anode supported substrate using RF magnetron sputtering are successfully prepared. The anode substrate is composed of two functional NiO/Sm0.2Ce0.8O2-δ (SDC) composite layers with ratios of 60/40 wt% and 50/50 wt% and a current collector layer of pure NiO. The as-deposited LSGM film appears to be amorphous in nature. After post-annealing at 1000 °C, a uniform and dense polycrystalline film with a composition of La0.87Sr0.13Ga0.85Mg0.15O3-δ and a thickness of 3.8 μm is obtained, which was well adhered to the anode substrate. A composite LSGM/La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) layer, with a ratio of 30/70 wt%, is used as the cathode. The SOFC prepared reveals a good mechanical integrity with no sign of cracking, delamination, or discontinuity among the interfaces. The total cell resistance of a single cell with LSGM electrolyte film declines from 0.60 to 0.10 Ω cm2 as the temperature escalates from 600 to 800 °C and the open circuit voltage (OCV) ranges from 0.85 to 0.95 V. The maximum power density (MPD) of the single cell is reported as 0.65, 1.02, 1.30, 1.42, and 1.38 W cm−2 at 600, 650, 700, 750, and 800 °C, respectively. The good cell performance leads to the conclusion that RF magnetron sputtering is a feasible deposition method for preparing good quality LSGM films in SOFCs.
Keywords	Solid oxide fuel cell; Sputtering; Electrolyte; Doped lanthanum gallate
Remark	doi:10.1016/j.jpowsour.2015.01.185 Link

ID=295

Binder Jetting: A Novel Solid Oxide Fuel-Cell Fabrication Process and Evaluation

Authors	Guha Manogharan, Meshack Kioko, Clovis Linkous
Source	JOM Volume: 67, Issue: 3, Pages: 660-667 Time of Publication: 2015
Abstract	With an ever-growing concern to find a more efficient and less polluting means of producing electricity, fuel cells have constantly been of great interest. Fuel cells electrochemically convert chemical energy directly into electricity and heat without resorting to combustion/mechanical cycling. This article studies the solid oxide fuel cell (SOFC), which is a high-temperature (100°C to 1000°C) ceramic cell made from all solid-state components and can operate under a wide range of fuel sources such as hydrogen, methanol, gasoline, diesel, and gasified coal. Traditionally, SOFCs are fabricated using processes such as tape casting, calendaring, extrusion, and warm pressing for substrate support, followed by screen printing, slurry coating, spray techniques, vapor deposition, and sputter techniques, which have limited control in substrate microstructure. In this article, the feasibility of engineering the porosity and configuration of an SOFC via an additive manufacturing (AM) method known as binder jet printing was explored. The anode, cathode and oxygen ion-conducting electrolyte layers were fabricated through AM sequentially as a complete fuel cell unit. The cell performance was measured in two modes: (I) as an electrolytic oxygen pump and (II) as a galvanic electricity generator using hydrogen gas as the fuel. An analysis on influence of porosity was performed through SEM studies and permeability testing. An additional study on fuel cell material composition was conducted to verify the effects of binder jetting through SEM–EDS. Electrical discharge of the AM fabricated SOFC and nonlinearity of permeability tests show that, with additional work, the porosity of the cell can be modified for optimal performance at operating flow and temperature conditions.
Remark	DOI 10.1007/s11837-015-1296-9 Link

ID=289

Pure and Mn-doped La4SrTi5O17 layered perovskite as potential solid oxide fuel cell material: Structure and anodic performance

Authors
Source	Journal of Power Sources Volume: 274, Pages: 806–815 Time of Publication: 2015
Abstract	Pure and 5% Mn doped layered perovskites La4SrTi5O17, members of the La4Srn-4(Ti,Mn)nO3n+2 series with n = 5, have been synthesized and investigated as anode materials for Solid Oxide Fuel Cells. The use of XRD, neutron and electron diffraction techniques allows clarifying some divergences concerning the structural characterization within the family, not only in air but also in anodic-like N2/H2(97/3) atmosphere. The electrical conductivity of both compounds is very low in air but those values increase by two orders of magnitude in diluted hydrogen. The study of catalytic properties for methane steam reforming as well as in-depth analysis of the SOFC anodic behaviour of both materials are described, for which a microstructure optimization of the electrode allows to demonstrate the potential interest of the lamellar materials upon the classical three-dimensional cubic-like LSTs.
Keywords	SOFC; Anode; Layered perovskite; Titanate; Methane steam reforming; Electrochemical impedance spectroscopy
Remark	doi:10.1016/j.jpowsour.2014.10.131 Link

ID=288

Electrochemical performance and carbon deposition resistance of Ce-doped La0.7Sr0.3Fe0.5Cr0.5O3-δ anode materials for solid oxide fuel cells fed with syngas

Authors	Yi-Fei Sun, Jian-Hui Li, Kart T. Chuang, Jing-Li Luo
Source	Journal of Power Sources Volume: 254, Pages: 483–487 Time of Publication: 2015
Abstract	Ce-doped La0.7Sr0.3Fe0.5Cr0.5O3-δ (Ce-LSFC) perovskite anode catalysts for solid oxide fuel cells are successfully synthesized by a modified combustion method for the first time. The pure perovskite structure without formation of CeO2 is obtained when the content of Ce ≤ 10%. Compared with La0.7Sr0.3Fe0.5Cr0.5O3-δ anode, Ce-LSFC anode not only shows much higher catalytic activity towards the oxidation of syngas with less carbon deposition, but also displays better regeneration from coking. The enhanced performance is attributed to the more available oxygen vacancies in lattice and better oxygen mobility after doping with Ce.
Keywords	SOFC; Ce-doped LSFC; Perovskite
Remark	doi:10.1016/j.jpowsour.2014.10.090 Link

ID=282

Characterization and Modeling of La 1 − x Sr x CoO 3 − δ Solid Oxide Fuel Cell Cathodes Using Nonlinear Electrochemical Impedance Techniques

Author	Timothy James McDonald
Source	Time of Publication: 2014
Remark	Dissertation Link

ID=281

Structural and electrical study of samarium doped cerium oxide thin films prepared by e-beam evaporation

Authors	Darius Virbukas, Mantas Sriubas, Giedrius Laukaitis
Source	Solid State Ionics Time of Publication: 2014
Abstract	Samarium doped cerium oxide (Sm0.15Ce0.85O1.925, SDC) thin films were grown on the Alloy 600 (Fe–Ni–Cr) and optical quartz (SiO2) substrates using e-beam deposition technique. Formed SDC thin films were characterized using different X-ray diffraction (XRD) techniques, scanning electron microscope (SEM), energy-dispersive spectrometry (EDS) and impedance spectroscopy. The deposition rate of formed SDC thin films was changed from 2 Å/s to 16 Å/s. XRD analysis shows that all thin films have a cubic (FCC) structure and repeat the crystallographic orientation of the initial powders evaporated with different deposition rate and on different substrates. The crystallite size increases from 7.7 nm to 10.3 nm and from 7.2 nm to 9.2 nm on Alloy 600 substrate and optical quartz (SiO2) substrate respectively as the thin film deposition rate increases. SEM images indicate a dense and homogeneous structure of all formed SDC thin films. The ionic conductivity depends on thin films density and blocking factor. The best ionic conductivity (σg = 1.34 Sm− 1 and σgb = 2.29 Sm −1 at 873 K temperature, activation energy ΔEg = 0.91 eV and ΔEgb = 0.99 eV) was achieved for SDC thin films formed at 4 Å/s deposition rate. It was found that the highest density (5.25 g/cm3) and the lowest relaxation time in grain (τg = 9.83 × 10− 7 s), and the lowest blocking factor (0.39) is in SDC thin films formed at 4 Å/s deposition rate. The deposition rate influences the stoichiometry of the formed SDC thin ceramic films.
Keywords	Electron beam deposition; Samarium doped ceria oxide (SDC); Solid oxide fuel cells (SOFC); Ionic conductivity
Remark	DOI: 10.1016/j.ssi.2014.09.036 Link

ID=277

Superior electrochemical performance and oxygen reduction kinetics of layered perovskite PrBaxCo2O5+δ (x = 0.90–1.0) oxides as cathode materials for intermediate-temperature solid oxide fuel cells

Authors	Jingping Wang, Fuchang Meng, Tian Xia, Zhan Shi, Jie Lian, Chunbo Xu, Hui Zhao, Jean-Marc Bassat, Jean-Claude Grenier
Source	International Journal of Hydrogen Energy Time of Publication: 2014
Abstract	The layered perovskite PrBaxCo2O5+δ (PBxCO, x = 0.90–1.0) oxides have been synthesized by a solid-state reaction technique, and evaluated as the potential cathode materials for intermediate-temperature solid oxide fuel cells (IT-SOFCs). Room temperature X-ray diffraction patterns show the orthorhombic structures which double the lattice parameters from the perovskite cell parameter as a ≈ ap, b ≈ ap and c ≈ 2ap (ap is the cell parameter of the primitive perovskite) in the Pmmm space group. There is a good chemical compatibility between the PBxCO cathode and the Ce0.9Gd0.1O1.95 (CGO) electrolyte at 1000 °C. The electrical conductivity and thermal expansion coefficient of PBxCO are improved due to the increased amount of electronic holes originated from the Ba-deficiency. The results demonstrate the high electrochemical performance of PBxCO cathodes, as evidenced by the super low polarization resistances (Rp) over the intermediate temperature range. The lowest Rp value, 0.042 Ω cm2, and the cathodic overpotential, −15 mV at a current density of −25 mA cm−2, are obtained in the PrBa0.94Co2O5+δ cathode at 600 °C in air, which thus allow to be used as a highly promising cathode for IT-SOFCs. A CGO electrolyte fuel cell with the PrBa0.94Co2O5+δ cathode presents the attractive peak power density of ∼1.0 W cm−2 at 700 °C. Furthermore, the oxygen reduction kinetics of the PrBa0.94Co2O5+δ cathode is also studied, and the rate-limiting steps for oxygen reduction reaction are determined at different temperatures.
Remark	DOI: 10.1016/j.ijhydene.2014.09.041 Link

ID=276

Organic–Inorganic Hybrid Membranes Based on Sulfonated Poly(ether ether ketone) and Tetrabutylphosphonium Bromide Ionic Liquid for PEM Fuel Cell Applications

Authors	Vijay Shankar Rangasamy, Savitha Thayumanasundaram, Niels de Greef, Jin Won Seo and Jean-Pierre Locquet
Source	European Journal of Inorganic Chemistry Time of Publication: 2014
Abstract	Ionic liquids (ILs), with their inherent ionic conductivity and negligible vapor pressure, can be exploited in proton exchange membrane (PEM) fuel cells for which thermal management is a major problem and the cell operation temperature is limited by the boiling point of water. In this work, sulfonated poly(ether ether ketone) (SPEEK) membranes were modified by the incorporation of tetrabutylphosphonium bromide ([P4 4 4 4]Br) by solvent-casting. Electrochemical impedance spectroscopy (EIS) was used to study the electrical properties of the modified membranes. Simultaneous TGA and FTIR studies were used to evaluate the thermal stability and chemical structure of the modified membranes, respectively. 1H NMR spectroscopy was applied to probe the changes in the chemical environment due to the interaction between the ionic liquid and the polymer. Mechanical properties were studied by dynamic mechanical analysis. The temperature-dependent behavior of the viscosity of the [P4 4 4 4]Br ionic liquid was observed to obey the Vogel–Fulcher–Tammann (VFT) equation, and was correlated to the ion-conducting properties of the IL-doped SPEEK membranes.
Remark	DOI: 10.1002/ejic.201402558 Link

ID=274

A family of oxide ion conductors based on the ferroelectric perovskite Na0.5Bi0.5TiO3

Authors	Ming Li, Martha J. Pietrowski, Roger A. De Souza, Huairuo Zhang, Ian M. Reaney, Stuart N. Cook, John A. Kilner & Derek C. Sinclair
Source	Nature Materials Volume: 13, Pages: 31-35 Time of Publication: 2014
Abstract	Oxide ion conductors find important technical applications in electrochemical devices such as solid-oxide fuel cells (SOFCs), oxygen separation membranes and sensors1, 2, 3, 4, 5, 6, 7, 8, 9. Na0.5Bi0.5TiO3 (NBT) is a well-known lead-free piezoelectric material; however, it is often reported to possess high leakage conductivity that is problematic for its piezo- and ferroelectric applications10, 11, 12, 13, 14, 15. Here we report this high leakage to be oxide ion conduction due to Bi-deficiency and oxygen vacancies induced during materials processing. Mg-doping on the Ti-site increases the ionic conductivity to ~0.01 S cm−1 at 600 °C, improves the electrolyte stability in reducing atmospheres and lowers the sintering temperature. This study not only demonstrates how to adjust the nominal NBT composition for dielectric-based applications, but also, more importantly, gives NBT-based materials an unexpected role as a completely new family of oxide ion conductors with potential applications in intermediate-temperature SOFCs and opens up a new direction to design oxide ion conductors in perovskite oxides.
Remark	doi:10.1038/nmat3782 Link

ID=270

Conductivity and oxygen reduction activity changes in lanthanum strontium manganite upon low-level chromium substitution

Authors	George Tsekouras, Artur Braun
Source	Solid State Ionics Volume: 266, Pages: 19-24 Time of Publication: 2014
Abstract	On the timescale of solid oxide fuel cell (SOFC) system lifetime requirements, the thermodynamically predicted low-level substitution of chromium on the B-site of (La,Sr)MnO3 could be a source of cathode degradation underlying more overt and well-known chromium poisoning mechanisms. To study this phenomenon in isolation, electronic conductivity (σ) and electrochemical oxygen reduction activity of the (La0.8Sr0.2)0.98CrxMn1−xO3 model series (x = 0, 0.02, 0.05 or 0.1) were measured in air between 850 and 650 °C. Depending on the extent of chromium substitution and the measurement temperature, electrochemical impedance spectroscopy (EIS) results could be deconvoluted into a maximum of three contributions reflecting possible limiting processes such as oxide ion transport and dissociative adsorption. Chromium substitution resulted in lowered σ (from 174 S cm− 1 (x = 0) to 89 S cm− 1 (x = 0.1) at 850 °C) and a steady rise in associated activation energy (Ea) (from 0.105 ± 0.001 eV (x = 0) to 0.139 ± 0.001 eV (x = 0.1)). From EIS analyses, ohmic and polarisation resistances increased, whilst Ea for the overall oxygen reduction reaction also increased from 1.39 ± 0.04 eV (x = 0) to 1.48–1.54 ± 0.04 eV upon chromium substitution.
Keywords	Solid oxide fuel cell; Lanthanum strontium manganite; Chromium poisoning; Electronic conductivity; Electrochemical impedance spectroscopy
Remark	Link

ID=269

The effect of calcination temperature on the electrochemical properties of La0.3Sr0.7Fe0.7Cr0.3O3−x (LSFC) perovskite oxide anode of solid oxide fuel cells (SOFCs)

Authors	Yifei Sun, Ning Yan, Jianhui Li, Huayi Wu, Jing-Li Luo, Karl T. Chuang
Source	Sustainable Energy Technologies and Assessments Volume: 8, Pages: 92-98 Time of Publication: 2014
Abstract	A series of perovskite structure anode materials, LSFC, was successfully prepared by a glycine combustion process and further calcined at different temperatures. The electrochemical properties of anodes prepared at various calcination temperatures (1100 °C, 1200 °C and 1300 °C) were investigated. The calcination temperature had no significant influence on the morphology of the material but showed obvious influences on the particle sizes and electrochemical properties of the materials. Higher calcination temperature results in sharper X-ray diffractometer (XRD) diffraction peaks of the materials with larger particle sizes and higher electrical conductivity. However materials calcined at higher temperature had much smaller BET surface area resulting in lower triple phase boundary (TPB). The electrochemical performance test exhibited that LSFC anode material sintered at 1100 °C exhibited the smallest area specific resistance (ASR) value in H2 at operating temperatures from 700 to 900 °C. For proton conducting SOFCs (PC-SOFCs) fed by syngas, the cell with anode calcined at 1100 °C also showed highest power density output of 120 mW/cm2 at 750 °C, which was almost three times higher than that of the cell with anode calcined at 1300 °C.
Keywords	Solid oxide fuel cell; Calcination temperature; Electrochemical properties; Perovskite
Remark	Link

ID=267

MICROWAVE SINTERING OF Sr AND Mg-DOPED LANTHANUM GALLATE (LSGM) SOLID ELECTROLYTES

Authors	Cristian Andronescu, Victor Fruth, Enikoe Volceanov, Rares Scurtu, Cornel Munteanu, Maria Zaharescu
Source	Romanian journal of materials Time of Publication: 2014-01
Abstract	Sr2+ and Mg2+ simultaneously doped lanthanum gallate (LSGM) powders, prepared by a modified Pechini route using polyvinyl alcohol (PVA) as polymeric alcohol, were densified using an activated microwave technique at 2.45 GHz, to develop a dense stable electrolyte for application in intermediate temperatures solid oxide fuel cells (IT-SOFC). Thermal behaviour of precursors was investigated by means of differential thermal analysis combined with thermogravimetric analysis (DTA/TGA). The powders and sintered samples were characterized using scanning electron microscopy and energy dispersive analysis (SEM-EDAX), X-ray diffraction (XRD) and infrared spectroscopy (FT-IR). The thermal expansion coefficient (TEC) and ionic conductivity of the sintered samples were also evaluated. Fine, homogeneous and high density pellets of almost pure LSGM phase were obtained after sintering at 14000C for a short period time in an activated microwave field. Using activated microwave field, due to the volumetric in situ heating, the sintering process is highly specific and instantaneous, leading to a faster kinetics compared to the conventional process (electric oven). With an optimized sintering schedule, a fine grained and dense microstructure of the samples were obtained.
Remark	Link

ID=266

Magnetron formation of Ni/YSZ anodes of solid oxide fuel cells

Authors	A. A. Solov’ev, N. S. Sochugov, I. V. Ionov, A. V. Shipilova, A. N. Koval’chuk
Source	Russian Journal of Electrochemistry Volume: 50, Issue: 7, Pages: 647-655 Time of Publication: 2014
Abstract	Physico-chemical and structural properties of nanocomposite NiO/ZrO2:Y2O3 (NiO/YSZ) films applied using the reactive magnetron deposition technique are studied for application as anodes of solid oxide fuel cells. The effect of oxygen consumption and magnetron power on the discharge parameters is determined to find the optimum conditions of reactive deposition. The conditions for deposition of NiO/YSZ films, under which the deposition rate is maximum (12 μm/h), are found and the volume content of Ni is within the range of 40–50%. Ni-YSZ films reduced in a hydrogen atmosphere at the temperature of 800°C have a nanoporous structure. However, massive nickel agglomerates are formed in the course of reduction on the film surface; their amount grows at an increase in Ni content in the film. Solid oxide fuel cells with YSZ supporting electrolyte and a LaSrMnO3 cathode are manufactured to study electrochemical properties of NiO/YSZ films. It is shown that fuel cells with a nanocomposite NiO/YSZ anode applied using a magnetron sputtering technique have the maximum power density twice higher than in the case of fuel cells with an anode formed using the high-temperature sintering technique owing to a more developed gas-anode-electrolyte three-phase boundary.
Remark	Link

ID=265

Full ceramic micro solid oxide fuel cells: towards more reliable MEMS power generators operating at high temperatures

Authors
Source	Energy Environ. Sci. Time of Publication: 2014
Abstract	Batteries, with a limited capacity, have dominated the power supply of portable devices for decades. Recently, the emergence of new types of highly efficient miniaturized power generators like micro fuel cells has opened up alternatives for continuous operation on the basis of unlimited fuel feeding. This work addresses for the first time the development of a full ceramic micro solid oxide fuel cell fabricated in silicon technology. This full-ceramic device represents a new generation of miniaturized power generators able to operate at high temperatures, and therefore able to work with a hydrocarbon fuel supply. Dense yttria-stabilized zirconia free-standing large-area membranes on micromachined silicon were used as the electrolyte. Thin-film porous electrodes of La0.6Sr0.4CoO3−δ and gadolinia-doped ceria were employed as cathode and anode materials, respectively. The electrochemical performance of all the components was evaluated by partial characterization using symmetrical cells, yielding excellent performance for the electrolyte (area specific resistance of 0.15 Ω cm2 at temperatures as low as 450 °C) and the electrodes (area specific resistance of the cathode and anode below 0.3 Ω cm2 at 700 °C). A micro solid oxide fuel cell with an active area of 2 mm2 and less than 1 micrometer in thickness was characterized under fuel cell conditions, using hydrogen as a fuel and air as an oxidant. A maximum power density of 100 mW cm−2 and 2 mW per single membrane was generated at 750 °C, having an open circuit voltage of 1.05 V. Impedance spectroscopy of the all-ceramic membrane showed a total area-specific resistance of [similar]3.5 Ω cm2.
Remark	DOI: 10.1039/C4EE00748D Link

ID=256

Mesoporous NiO-Samaria Doped Ceria for Low-Temperature Solid Oxide Fuel Cells

Authors	Kim, Jin-Yeop; Kim, Ji Hyeon; Choi, Hyung Wook; Kim, Kyung Hwan; Park, Sang Joon
Source	Journal of Nanoscience and Nanotechnology Volume: 14, Issue: 8, Pages: 6399-6403(5) Time of Publication: 2014
Abstract	In order to prepare anode material for low-temperature solid oxide fuel cells (SOFCs), the mesoporous NiO-SDC was synthesized using a cationic surfactant (cetyltrimethyl-ammonium bromide; CTAB) for obtaining wide triple-phase boundary (TPB). In addition, Ni-SDC anode-supported SOFC single cells with YSZ electrolyte and LSM cathode were fabricated and the performance of single cells was evaluated at 600 °C. The microstructure of NiO-SDC was characterized by XRD, EDX, SEM, and BET, and the results showed that the mesoporous NiO-SDC with 10 nm pores could be obtained. It was found that the surface area and the electrical performance were strongly influenced by the Ni content in Ni-SDC cermets. After calcined at 600 °C, the surface area of NiO-SDC was between 90–117 m2/g at 35–45 Ni wt%, which was sufficiently high for providing large TPB in SOFC anode. The optimum Ni content for cell performance was around 45 wt% and the corresponding MPD was 0.36 W/cm2. Indeed, the mesoporous NiO-SDC cermet may be of interest for use as an anode for low-temperature SOFCs.
Remark	DOI: http://dx.doi.org/10.1166/jnn.2014.8452 Link

ID=255

Oxide ion transport in (Nd2−xZrx)Zr2O7+δ electrolytes by an interstitial mechanism

Authors	A.V. Shlyakhtina, D.A. Belov, A.V. Knotko, M. Avdeev, I.V. Kolbanev, G.A. Vorobieva, O.K. Karyagina, L.G. Shcherbakova
Source	Journal of Alloys and Compounds Volume: 603, Issue: 5, Pages: 274–281 Time of Publication: 2014
Abstract	We have studied the structure and transport properties of ten (Nd2−xZrx)Zr2O7+x/2 (x = 0–1.27) solid solutions, which lie in the ZrO2–Nd2Zr2O7 isomorphous miscibility range. Major attention has been focused on the pyrochlore-like (Nd2−xZrx)Zr2O7+x/2 solid solutions with x = 0–0.78, which are thought to be potential interstitial oxide ion conductors. The X-ray and neutron diffraction results demonstrate that the (Nd2−xZrx)Zr2O7+x/2 (x = 0–1.27) solid solutions undergo an order–disorder (pyrochlore–defect fluorite) structural phase transition. The (Nd2−xZrx)Zr2O7+x/2 (x = 0.2–0.78) have the bulk conductivity, ∼(1.2–4) × 10–3 S/cm at 750 °C, which is two orders of magnitude higher than that of the ordered pyrochlore Nd2Zr2O7. An attempt has been made to determine the interstitial oxygen content of (Nd2−xZrx)Zr2O7+x/2 (x = 0.2; 0.67) in a reducing atmosphere using thermogravimetry and mass spectrometry. It has been shown that no reduction occurs in the NdZrO system, where neodymium has only one oxidation state, 3+.
Keywords	Fuel cells; Ionic conduction; Electrochemical impedance spectroscopy; Neutron diffraction; X-ray diffraction; SEM
Remark	http://dx.doi.org/10.1016/j.jallcom.2014.03.068 Link

ID=254

Application of PVD methods to solid oxide fuel cells

Authors	A.A. Solovyeva, N.S. Sochugov, S.V. Rabotkin, A.V. Shipilova, I.V. Ionov, A.N. Kovalchuk, A.O. Borduleva
Source	Applied Surface Science Time of Publication: 2014
Abstract	In this paper, attention is paid to the application of such a method of vacuum physical vapor deposition (PVD) as magnetron sputtering for fabrication of a solid oxide fuel cell (SOFC) materials and structures. It is shown that the YSZ (yttria-stabilized zirconia) electrolyte and Ni–YSZ anode layers with required thickness, structure and composition can be effectively formed by PVD methods. The influence of parameters of pulsed power magnetron discharge on the deposition rate and the microstructure of the obtained YSZ electrolyte films were investigated. It is shown that the deposition rate of the oxide layers by magnetron sputtering can be significantly increased by using asymmetric bipolar power magnetrons, which creates serious prerequisites for applying this method on the industrial scale. Porous Ni–YSZ anode films were obtained by reactive co-sputtering of Ni and Zr–Y targets and subsequent reduction in the H2 atmosphere at a temperature of 800 °C. The Ni–YSZ films comprised small grains and pores of tens of nanometers.
Keywords	Solid oxide fuel cell; Metal support; Magnetron sputtering; Thin film; YSZ electrolyte; NiO/YSZ anode
Remark	http://dx.doi.org/10.1016/j.apsusc.2014.03.163 Link

ID=253

Proton conduction in oxygen deficient Ba3In1.4Y0.3M0.3ZrO8 (M = Ga3+ or Gd3+) perovskites

Authors	Francis G. Kinyanjui, Stefan T. Norberg, Christopher S. Knee, Sten-G. Eriksson
Source	Journal of Alloys and Compounds Volume: 605, Pages: 56-62 Time of Publication: 2014
Abstract	B -site disordered, oxygen deficient Ba3In1.4Y0.3M 0.3ZrO8 (M = Gd3+ or Ga3+) perovskites of space group View the MathML sourcePm3‾m, were prepared by a solid-state reactive sintering method. Thermogravimetric analysis of the as-prepared samples revealed 79.3% and 55.5% protonation of the available oxygen vacancies by OH groups in the Gd3+ and Ga3+ containing samples, respectively. Conductivity was found to be in the range of 0.3–1.1 × 10−3 S cm−1 (M = Gd3+) and 1.1–4.6 × 10−4 S cm−1 (M = Ga3+) for the temperature interval 300–600 °C in wet Argon. Ba3In1.4Y0.3Ga0.3ZrO8 shows an approximate one order of magnitude increase in conductivity at T > 600 °C under dry oxygen indicating a significant p-type contribution whereas Ba3In1.4Y0.3Gd0.3ZrO8 reveals a smaller enhancement. Ba3In1.4Y0.3Ga0.3ZrO8 displays considerable mixed proton–electronic conduction in the interval 400–800 °C under wet oxidising conditions suggesting possibility of Ga-containing compositions as a cathode materials in a proton conducting fuel cell.
Keywords	Proton conducting electrolyte; Oxygen deficient perovskite; Mixed conductor; Cathode material; Impedance spectroscopy

ID=250

Solid Oxide-Molten Carbonate Nano-composite Fuel Cells: Particle Size Effect

Authors	Shalima Shawuti, Mehmet A. Gulgun
Source	Journal of Power Sources Time of Publication: 2014
Abstract	Varying the amount of specific interface area in the CeO2-Na2CO3 nano-composite fuel cell electrolyte helped reveal the role of interfaces in ionic conductivity. We mixed ceria particles with micrometer or nanometer size distributions to obtain a specific surface area (SSA) in the composite from 47 m2/g to 203 m2/g. Micro-structural investigations of the nano-composite showed that the Na2CO3 phase serves as the glue in the microstructure, while thermal analysis revealed a glass transition-like behavior at 350 °C. High SSA enhanced the ionic conductivity significantly at temperatures below 400 °C. Moreover, the activation energy for the Arrhenius conductivity (σT) of the composites was lower than that of the Na2CO3 phase. This difference in the activation energies is consistent with the calculated dissociation energy of the carbonate phase. The strong dependence of conductivity on the SSA, along with differences in the activation energies, suggests that the oxide surface acted as a dissociation agent for the carbonate phase. A model for the solid composite electrolyte is proposed: in the nano-composite electrolyte, the oxide surface helps Na2CO3 dissociate, so that the "liberated" ions can move more easily in the interaction region around the oxide particles, thus giving rise to high ionic conductivities.
Keywords	composite electrolyte; ionic conductivity; impedance spectroscopy; SOFC; interphase; activation energy
Remark	in press, http://dx.doi.org/10.1016/j.jpowsour.2014.05.010 Link

ID=247

Doped Germanate-Based Apatites as Electrolyte for Use in Solid Oxide Fuel Cells

Authors	S.-F. Wang, Y.-F. Hsu, W.-J. Lin and K. Kobayashi
Source	Fuel Cells Time of Publication: 2014
Abstract	Apatite ceramics, known for their good electrical conductivities, have garnered substantial attention as an alternative electrolyte for solid oxide fuel cells (SOFCs). However, studies focusing on the electrochemical performances of SOFCs with apatities as electrolytes remain rare, partly due to their high sintering temperature. In this study, the effects of Mg2+, Al3+, Ga3+, and Sn4+ dopants on the characteristics of La9.5Ge6O26 ± δ are examined and their potential for use as SOFC electrolytes evaluated. The results indicate that La9.5Ge5.5Al0.5O26 is stabilized into a hexagonal structure, while the La9.5Ge5.5Sn0.5O26.25, La9.5Ge5.5Ga0.5O26, and La9.5Ge5.5Mg0.5O25.75 ceramics reveal triclinic cells accompanied with the second phase La2Sn2O7 or La2GeO5. The study further demonstrates that a high sintering temperature is needed for both the La9.5Ge5.5Mg0.5O25.75 and the La9.5Ge5.5Sn0.5O26.25 ceramics, and the worst electrical conductivity among the examined systems appears in the La9.5Ge5.5Ga0.5O26 ceramic. The La9.5Ge5.5Al0.5O26 ceramic is accordingly selected for cell evaluation due to its ability to reach densification at 1,350 °C, its good electrical conductivity of 0.026 S cm–1 at 800 °C, and its acceptable thermal expansion coefficient of 10.1 × 10–6 K–1. The maximum power densities of the NiO-SDC/La9.5Ge5.5Al0.5O26/LSCF-SDC single cell are found to be respectively 0.22, 0.16, 0.11, and 0.07 W cm–2 at 950, 900, 850, and 800 °C.
Keywords	Apatites; Cell Performance; Electrolyte; Impedance; Solid Oxide Fuel Cell
Remark	Article first published online: 19 FEB 2014 DOI: 10.1002/fuce.201300093 Link

ID=239

Synthesis and characterization of the micro-mesoporous anode materials and testing of the medium temperature solid oxide fuel cell single cells

Author	Kadi Tamm
Source	Time of Publication: 2013
Remark	Dissertation Link

ID=237

Effect of Ni Concentration on Phase Stability, Microstructure and Electrical Properties of BaCe0.8Y0.2O3-δ - Ni Cermet SOFC Anode and its application in proton conducting ITSOFC

Authors	Pooja Sawant, S. Varma, M.R. Gonal, B.N. Wani, Deep Prakash, S.R. Bharadwaj
Source	Electrochimica Acta Time of Publication: 2013
Abstract	In this work we have studied the effect of Ni concentration on phase stability, microstructure and electrical properties of BaCe0.8Y0.2O3-δ (BCY)-Ni cermet SOFC anode. It has been seen that Ni forms composite with BCY without forming any solid solution in both oxidized and reduced state. Also, microstructural analysis reveals the effect of Ni on porosity and triple phase boundaries necessary for electrochemical reactions during cell operation. Electrical conductivity values obtained from dc four probe technique in H2 atmosphere increase with an increase in Ni content. Composites with low vol% of Ni contents i.e. 19% (Ni19) and 26% (Ni26) show predominantly semiconductor-like behaviour whereas higher vol% viz. 35% (Ni35), 45% (Ni45) and 56% (Ni56) composites show electronic conductivity behaviour. This confirms that electronic conduction occurs through metallic Ni phase. Also, anode supported single cell for proton conducting SOFC has been fabricated using Ni35 composition and its current-potential characteristics measured at different temperatures.
Keywords	Cermet; X-ray diffraction; Electrical conductivity; Four probe; Single Cell
Remark	Available online 25 December 2013 Link

ID=236

Cathode compatibility, operation, and stability of LaNbO4-based proton conducting fuel cells

Authors
Source	Solid State Ionics Time of Publication: 2013
Abstract	Cathodes compatible with Ca-doped LaNbO4 (LCNO) and the operation of a complete proton conducting fuel cell based on this electrolyte are presented. The best performing cathode was a 50 vol.% La0.8Sr0.2MnO3 (LSM)–50 vol.% LCNO composite, with an overall area specific resistance (ASR) of ~ 10 Ω cm2 at 800 °C in wet air. Pt and La0.8Sr0.2(Cr0.5Mn0.5)O3-based cathodes exhibit higher ASRs. The performance of a complete Ni–LCNO//LCNO//LSM–LCNO fuel cell shows a high open circuit voltage but with relatively low performance, in agreement with the modest proton conductivity of LaNbO4-based materials and cathode performances. The cell exhibits stable operation with CO2 containing atmosphere on the cathode side, confirming the chemical robustness of LaNbO4-based electrolytes.
Keywords	Proton conducting fuel cells; Manufacturing; Impedance spectroscopy; LaNbO4; Characterization; Cathode performance
Remark	Available online 22 December 2013; Link

ID=233

Porous La 0.6 Sr 0.4 CoO 3-δ thin film cathodes for large area micro solid oxide fuel cell MEMS power generators

Authors
Source	Journal of Power Sources Time of Publication: 2013
Abstract	Porous La0.6Sr0.4CoO3-δ thin films were fabricated by pulsed laser deposition for being used as a cathode for micro solid oxide fuel cell applications as MEMS power generators. Symmetrical La0.6Sr0.4CoO3-δ/yttria-stabilized zirconia/La0.6Sr0.4CoO3-δ free-standing membranes were fabricated using silicon as a substrate. A novel large-area membrane design based on grids of doped-silicon slabs. Thermo-mechanical stability of the tri-layer membranes was ensured in the intermediate range of temperatures up to 700°C. In-plane conductivity of ca. 300 S/cm was measured for the cathode within the whole range of application temperatures. Finally, area specific resistance values below 0.3 Ω·cm2 were measured for the cathode/electrolyte bi-layer at 700°C in the exact final micro solid oxide fuel cell device configuration, thus presenting La0.6Sr0.4CoO3-δ as a good alternative for fabricating reliable micro solid oxide fuel cells for intermediate temperature applications.
Keywords	Micro Solid Oxide Fuel Cell, thin film cathode, self-supported electrolyte
Remark	DOI: 10.1016/j.jpowsour.2013.10.038

ID=228

Nanocrystalline Sm0.5Sr0.5CoO3−δ synthesized using a chelating route for use in IT-SOFC cathodes: microstructure, surface chemistry and electrical conductivity

Authors	Rares Scurtu, Simona Somacescu, Jose Maria Calderon-Moreno, Daniela Culita, Ion Bulimestru, Nelea Popa, Aurelian Gulea, Petre Osiceanu
Source	Journal of Solid State Chemistry Time of Publication: 2013
Abstract	Nanocrystalline Sm0.5Sr0.5CoO3−δ powders were synthesized by a chelating route using different polyfunctional HxAPC acids (APC=aminopolycarboxylate; x= 3, 4, 5). Different homologous aminopolycarboxylic acids, namely nitrilotriacetic (H3nta), ethylenediaminetetraacetic (H4edta), 1,2-cyclohexanediaminetetracetic (H4cdta) and diethylenetriaminepentaacetic (H5dtpa) acid, were used as chelating agents to combine Sm, Sr, Co elements into a perovskite structure. The effects of the chelating agents on the crystalline structure, porosity, surface chemistry and electrical properties were investigated. The electrical properties of the perovskite-type materials emphasized that their conductivities in the temperature range of interest (600–800 °C) depend on the nature of the precursors as well as on the presence of a residual Co oxide phase as shown by XRD and XPS analysis. The surface chemistry and the surface stoichiometries were determined by XPS revealing a complex chemical behavior of Sr that exhibits a peculiar „surface phase” and „bulk phase” chemistry within the detected volume (<10 nm).
Keywords	Cathode; Perovkites; Electrical Conductivity; XPS; IT-SOFC
Remark	Available online 5 November 2013 Link

ID=225

Synthesis and Investigation of Porous Ni–Al Substrates for SolidOxide Fuel Cells

Authors	A. A. Solov’ev, N. S. Sochugov , I. V. Ionov , A. I. Kirdyashkin , V. D. Kitler , A. S. Maznoi , Yu. M. Maksimov , and T. I. Sigfusson
Source	Materials of power engineering and radiationresistant materials Time of Publication: 2013-10
Abstract	Selfpropagating hightemperature synthesis (SHS) is applied for the production of porous supporting Ni–Al bases of solidoxide fuel cells. The effect of synthesis onditions and the composition of source powders on the phase composition, microstructure, gas permeability, corrosion resistance, and other proper ties of obtained Ni–Al samples is investigated. The possibility is shown for the formation of solidoxide fuel cells (SOFCs) on the surface of porous Ni–Al plates. The cells have the structure Ni–ZrO3:Y2O3 anode/ZrO3:Y2O3 electrolyte/La0.8Mn0.2SrO3 cathode and provide a specific power of 400 mW/cm2 at a temperature of 800°C.
Keywords	selfpropagating hightemperature synthesis, Ni–Al, solidoxide fuel cells, ZrO3:Y2O3 electrolyte, magnetron sputtering.
Remark	Link

ID=224

Galliosilicate glasses for viscous sealants in solid oxide fuel cell stacks: Part III: Behavior in air and humidified hydrogen

Authors	T. Jin, M.O. Naylor, J.E. Shelby, S.T. Misture
Source	International Journal of Hydrogen Energy Time of Publication: 2013
Abstract	Optimized boro-galliosilicate glasses were selected to evaluate their viscous sealing performance in both air and humidified hydrogen atmospheres. Selected low-alkali and alkali-free glasses show excellent performance, with viscous behavior maintained for more than 1000 h in wet hydrogen. Candidate sealants were thermally treated at 850 and 750 °C for up to 1000 h in contact with alumina coated 441 stainless steel (Al-SS) and 8 mol% yttria-stabilized zirconia (8YSZ). Each sealant crystallizes appreciably by 1000 h, and their coefficients of thermal expansion range from 10.2 to 11.7 × 10−6 K−1, 100–400 °C. The remnant amorphous phases in most of the partially crystallized sealants show softening points near or below the target operating temperatures, thus enabling viscous sealing. Humidified hydrogen in general increases the rate of crystallization but does not change the crystalline phases formed or interactions with 8YSZ. For the low-alkali GaBA series, wet H2 enhances the interfacial interaction between potassium in the glass phase and the protective alumina coating on the stainless steel.
Keywords	Solid oxide fuel cell; Sealing glass; Galliosilicate; Thermal expansion; Hydrogen
Remark	Available online 25 October 2013 Link

ID=223

Porous La0.6Sr0.4CoO3-δ thin film cathodes for large area micro solid oxide fuel cell MEMS power generators

Authors
Source	Journal of Power Sources Time of Publication: 2013
Abstract	Porous La0.6Sr0.4CoO3-δ thin films were fabricated by pulsed laser deposition for being used as a cathode for micro solid oxide fuel cell applications as MEMS power generators. Symmetrical La0.6Sr0.4CoO3-δ/yttria-stabilized zirconia/La0.6Sr0.4CoO3-δ free-standing membranes were fabricated using silicon as a substrate. A novel large-area membrane design based on grids of doped-silicon slabs. Thermo-mechanical stability of the tri-layer membranes was ensured in the intermediate range of temperatures up to 700°C. In-plane conductivity of ca. 300 S/cm was measured for the cathode within the whole range of application temperatures. Finally, area specific resistance values below 0.3 Ω·cm2 were measured for the cathode/electrolyte bi-layer at 700°C in the exact final micro solid oxide fuel cell device configuration, thus presenting La0.6Sr0.4CoO3-δ as a good alternative for fabricating reliable micro solid oxide fuel cells for intermediate temperature applications.
Remark	Available online 18 October 2013 Link

ID=222

Nano Coated Interconnects for SOFC (NaCoSOFC)

Authors
Source	ECS Transactions Volume: 57, Issue: 1, Pages: 2187-2193 Time of Publication: 2013
Abstract	The NaCoSOFC project is focused on the development of nano coatings for SOFC interconnects. The project is sponsored by the Nordic Top Level Research Initiative and has four project partners: Sandvik Materials Technology which is producing coated interconnects, Chalmers University of Technology and the University of Oslo that characterize samples with respect to e.g. corrosion, Cr evaporation and ASR as well as Topsoe Fuel Cell that is testing the developed interconnects in its stacks. The developed coatings are based on a combination of Co with RE elements and exhibit high corrosion resistance, 10 fold decrease in Cr evaporation and ASR values that are approximately 50% of the uncoated material.
Remark	Link

ID=221

Nano Coated Interconnects for SOFC (NaCoSOFC)

Source

Time of Publication: 2013

ID=220

Application of FIB-TOF-SIMS and FIB-SEM-EDX Methods for the Analysis of Element Mobility in Solid Oxide Fuel Cells

Authors
Source	ECS Transactions Volume: 57, Issue: 1, Pages: 581-587 Time of Publication: 2013
Abstract	The solid oxide fuel cell single cells with porous Pr0.6Sr0.4CoO3-δ and La0.6Sr0.4CoO3-δ (PSCO, LSCO respectively) cathodes on compact Ce0.9Gd0.1O2-δ\|Zr0.85Y0.15O2-δ or Ce0.9Gd0.1O2-δ\|Zr0.85Sc0.15O2-δ bi-layered electrolytes deposited onto Ni-Zr0.85Y0.15O2-δ (Ni-ZYO) or Ni- Ce0.9Gd0.1O2-δ (Ni-CGO) supporting anode were prepared for ion (element) mobility studies. Focused ion beam - time of flight - secondary ion mass spectrometry (FIB-TOF-SIMS) method in addition to FIB-SEM, SEM-EDX and XRD methods has been used for analysis of mass-transfer (interlayer diffusion) of cathode electrode elements, demonstrating that during PSCO and LSCO sintering at 1100°C on to CGO\|ZYO or CGO\|ZScO bilayered electrolyte, noticeable mass-transfer of Sr2+ cations through the partially microporous CGO has been verified using FIB-TOF-SIMS and SEM-EDX methods. The single cells have been additionally studied using cyclic voltammetry, electrochemical impedance and chronoamperometry methods and high power densities have been demonstrated.
Remark	Link

ID=208

Effects of Nb5+, Mo6+, and W6+ dopants on the germanate-based apatites as electrolyte for use in solid oxide fuel cells

Authors	Sea-Fue Wang, Yung-Fu Hsu, Wan-Ju Lin
Source	International Journal of Hydrogen Energy Volume: 38, Issue: 27, Pages: 12015–12023 Time of Publication: 2013-09
Abstract	Rare information is available in the literature on the cell performance of the solid oxide fuel cells (SOFCs) using apatites known for their good electrical conductivity as electrolyte materials. In this study, La9.5Ge5.5Nb0.5O26.5, La9.5Ge5.5Mo0.5O26.75, and La9.5Ge5.5W0.5O26.75 ceramics were prepared and characterized. The results indicated that the La9.5Ge5.5Nb0.5O26.5 and La9.5Ge5.5W0.5O26.75 ceramics reported hexagonal phase, while the La9.5Ge5.5Mo0.5O26.75 ceramic demonstrated triclinic symmetry. Among the apatities evaluated, La9.5Ge5.5Nb0.5O26.5 sintered at 1450 °C showed the best conduction with an electrical conductivity value of 0.045 S/cm at 800 °C. Button cells of NiO–SDC/La9.5Ge5.5Nb0.5O26.5/LSCF–SDC were built and revealed good structural integrity. The total ohmic resistance (R0) and interfacial polarization resistance (RP) of the cell read 0.428 and 0.174 Ω cm2 and 0.871 and 1.164 Ω cm2, respectively at 950 and 800 °C. The maximum power densities (MPD) of the single cell at 950 and 800 °C were respectively 0.363 and 0.095 W cm−2. Without optimizing the anode and cathode as well as hermetic sealing of the cell against the gas, the study found the performance of the single cell with the pure La9.5Ge5.5Nb0.5O26.5 as its electrolyte material superior to those of the SOFC cells with a YSZ electrolyte of comparable thickness shown in the literature.
Keywords	Solid oxide fuel cell; Apatite; Impedance; Cell performance
Remark	Link

ID=202

Metallic Interconnects for Proton Ceramic Fuel Cells. Oxidation behavior and transport properties under simulated fuel cell conditions

Author	Anders Werner Bredvei Skilbred
Source	Time of Publication: 2013-03
Remark	Dissertation for the degree of Philosophiae Doctor Link

ID=191

Characteristics of SrCo1 − xSnxO3 − δ cathode materials for use in solid oxide fuel cells

Authors	Sea-Fue Wang, Yung-Fu Hsu, Chun-Ting Yeh, Chien-Chung Huang, Hsi-Chuan Lu
Source	Solid State Ionics Volume: 227, Pages: 10–16 Time of Publication: 2012-10
Abstract	In this study, introduction of tin ions in the SrCoO3 − δ oxide is attempted to modify its electrochemical behavior for serving as a cathode of intermediate-temperature solid oxide fuel cells (IT-SOFCs). Doping of tin ions appears to stabilize the cubic Pm-3m phase of the SrCo1 − ySnyO3 − δ ceramics but generates SrSnO3 precipitates and inhibits the grain growth as y value rises to a level greater than 10%. Obtained at 550 °C, the maximum electrical conductivity of SrCo0.95Sn0.05O3 − δ reads 545 S cm− 1. Single cells with a structure of NiO–Sm0.2Ce0.8O2 − δ (SDC)/SDC/SrCo0.95Sn0.05O3 − δ–SDC are built and characterized. Though SrCo0.95Sn0.05O3 − δ is regarded as an MIEC (mixed ionic/electronic conductivity material), adding SDC to SrCo0.95Sn0.05O3 − δ guarantees good adhesion to and fine electrical contact with the electrolyte layer, thereby contributing to the reduction in R0 and RP values. The single cell with the SrCo0.95Sn0.05O3 − δ–SDC composite cathode at 700 °C registers respectively an R0 value of 0.044 Ω cm2 and an RP value of 0.109 Ω cm2. In the absence of microstructure optimization and hermetic sealing of cells, a high power density of 0.847 W cm− 2 is reached. SrCo1 − ySnyO3 − δ thus emerges to be a promising cathode material for IT-SOFCs applications.
Keywords	Solid oxide fuel cell; Cathode; Impedance; Cell performance
Remark	Link

ID=186

Effects of the microwave heating on the properties of gadolinium-doped cerium oxide prepared by polyol method

Authors	A. Gondolini, E. Mercadelli, A. Sanson, S. Albonetti, L. Doubova, S. Boldrini
Source	Journal of the European Ceramic Society Volume: 33, Issue: 1, Pages: 67–77 Time of Publication: 2013
Abstract	Gadolinium doped ceria (GDC) has received a lot of attention as possible electrolyte material for Intermediate-Temperature (500–800 °C) Solid Oxide Fuel Cells (IT-SOFC). Microwave heating has been recently considered in combination with precipitation for the production of oxide or non-oxide nano-powders. In this study, crystalline CeO2 powders doped with different amount of gadolinium were successfully prepared by microwave-assisted polyol method under mild conditions and in one single step. The microwave heating was found to strongly influence the morphological properties of the powder especially for low gadolinium content. IR and thermal analyses helped to identify the major reaction path for the formation of the as-observed complex morphologies. Regardless to the morphology, the powders showed good densification behavior and expected electrochemical properties; Ce0.9Gd0.1O1.95 exhibited the highest conductivity.
Keywords	Doped ceria; Microwave processing; Ionic conductivity; Fuel cells; Polyol method
Remark	Link

ID=185

Investigating Reliability on Fuel Cell Model Identification. Part II: An Estimation Method for Stochastic Parameters

Authors	L. Tsikonis, S. Diethelm, H. Seiler, A. Nakajo, J. Van herle, D. Favrat
Source	Fuel Cells Time of Publication: 2012-08
Abstract	An alternative way to process data from polarization measurements for fuel cell model validation is proposed. The method is based on re- and subsampling of I–V data, with which repetitive estimations are obtained for the model parameters. This way statistics such as standard deviations and correlations between the parameters may be experimentally derived. Histograms may also be produced, approximating the probability distributions that they follow. Two experimental case studies are discussed. In the first case, observations are made on the behavior of the parameter values for two mathematical models. As the number of data points (measurement points) employed in the estimation of the parameters increases, parameters with high variances converge to specific values. On the contrary, parameters with small variances diverge linearly. The parameters' histograms do not usually follow normal distributions rather they show a connection between the number of peaks in the graphs and correlations of the parameters. The second case study is an application on a fast degraded SOFC button cell, where the values and the histograms of the parameters are compared before and after degradation.
Keywords	Data Fitting; Design of Experiments; Diagnostics; Fast Degradation; Identification; Parameter Estimation; Polarization Curves; Robust Regression; Solid Oxide Fuel cells; Stein's Paradox
Remark	DOI: 10.1002/fuce.201200031 Link

ID=182

Sr1−xPrxCo0.95Sn0.05O3−δ ceramic as a cathode material for intermediate-temperature solid oxide fuel cells

Authors	Sea-Fue Wang, Yung-Fu Hsu, Hsi-Chuan Lu, Chien-Chung Huang, Chun-Ting Yeh
Source	International Journal of Hydrogen Energy Volume: 37, Issue: 17, Pages: 12548–12556 Time of Publication: 2012-10
Abstract	In this study, the physical properties of the Sr1−xPrxCo0.95Sn0.05O3−δ ceramics were measured and their potential for use as a cathode material of intermediate-temperature solid oxide fuel cells (IT-SOFCs) was evaluated. A cubic phase was retained in all of the Sr1−xPrxCo0.95Sn0.05O3−δ ceramics. Analysis of the temperature-dependent conductivity found the SrCo0.95Sn0.05O3−δ and Sr0.9Pr0.1Co0.95Sn0.05O3−δ ceramics exhibiting semiconductor-like behavior below 550 °C and metal-like behavior above the same temperature. The Sr0.8Pr0.2Co0.95Sn0.05O3−δ and Sr0.7Pr0.3Co0.95Sn0.05O3−δ ceramics, however, reported a metal-like conductivity in the whole temperature range. The electrical conductivities of the Sr0.8Pr0.2Co0.95Sn0.05O3−δ ceramic at 500 °C and 700 °C read respectively 1250 S/cm and 680 S/cm, both of which were superior than those in most of the common perovskites. Single cells with a structure of NiO–Sm0.2Ce0.8O2−δ (SDC)/SDC/Sr0.8Pr0.2Co0.95Sn0.05O3−δ-SDC were built and characterized. Addition of SDC in Sr0.8Pr0.2Co0.95Sn0.05O3−δ emerged to be a crucial factor reducing the ohmic resistance (R0) and polarization resistance (RP) of the cell by facilitating a better adhesion to and electrical contact with the electrolyte layer. The R0 and RP of the cell read respectively 0.068 Ω cm2 and 0.0571 Ω cm2 at 700 °C and 0.298 Ω cm2 and 1.310 Ω cm2 at 550 °C. With no microstructure optimization and hermetic sealing of the cells, maximum power density (MPD) and open circuit voltage (OCV) reached respectively 0.872 W/cm2 and 0.77 V at 700 °C and 0.482 W/cm2 and 0.86 V at 550 °C. It is evident that Sr1−xPrxCo0.95Sn0.05O3−δ is a promising cathode material for IT-SOFCs.
Keywords	Solid oxide fuel cell; Cathode; Impedance; Cell performance
Remark	Link

ID=174

High Power Plasma Sprayed Intermediate Temperature Solid Oxide Fuel Cells with Sm0.5Sr0.5CoO3-δ Cathode

Authors	Chang-sing Hwang , Chun-Huang Tsai, Chun-Liang Chang, Jen-Feng Yu, Sheng-Hui Nien
Source	Procedia Engineering Volume: 36, Pages: 81–87 Time of Publication: 2012-05
Abstract	The cells with porous Ni/Fe(∼10 wt%) metal plate as a supporting substrate, double layers of La0.75Sr0.25Cr0.5Mn0.5 O3-δ (LSCM) and nanostructured Ce0.55La0.45O2-δ/Ni (LDC/Ni) as an anode, LDC as an anode interlayer, La0.8Sr0.2Ga0.8Mg0.2O3-δ (LSGM) as an electrolyte, LSGM/Sm0.5Sr0.5CoO3-δ (SSC) as a cathode interlayer and SSC as a cathode current collector, were prepared by atmospheric plasma spraying (APS) coating processes followed by a heating treatment. The current-voltage-power and AC impedance measurement results show that the prepared cell heat-treated at 850 °C for 3 hours in air with a dead load of 1000 g cm-2 has an attracting performance. The measured maximum output power densities of this cell have reached 0.777, 0.742, 0.659, 0.542, 0.393, and 0.250 W cm-2 at 800, 750, 700, 650, 600, and 550 °C respectively. The measured ohmic and polarization resistances are 0.241, 0.254, 0.282, 0.328, 0.42, 0.62 and 0.055, 0.064, 0.083, 0.128, 0.23, 0.471 Ω cm2 at 800, 750, 700, 650, 600, and 550 °C respectively. After correction of the resistance inside the ProboStat system, the predicted actual maximum power densities that a cell can deliver are 1.95, 1.613, 1.186, 0.823, 0.512, and 0.293 W cm-2 at 800, 750, 700, 650, 600, and 550 °C respectively.
Keywords	Atmospheric plasma spray; solid oxide fuel cells; metal-supported; nanostructured; Sm0.5Sr0.5CoO3-δ
Remark	Link

ID=172

Process and Apparatus of CO2 Energy Source Adopted in Solid Oxide Fuel Cell - CO2 Energy Conversion Cycle

Authors	M. Lee, C. Wang, Y. Chang, W. Kao, T. Lin, J. Chang, R. Yang, L. Lee
Source	Time of Publication: 2012-05
Abstract	A process and apparatus of “Solid Oxide Fuel Cell (SOFC)-CO2 Energy Conversion Cycle (referred to as SOFC-CO2-ECC)” are invented to adopt CO2 as energy sources from waste/stock gas or convert and fix it in the useful compounds. CO2 is converted into CO and O2 via simultaneously catalytic and electrochemical reactions in SOFC for power generation and CO2 cracking. Furthermore, CO is used either as the fuel in SOFC for power generation or starting materials in the chemical reactors to produce CO-derivatives of energy source materials and useful chemical compounds. Hence, SOFC-CO2-ECC is an active or scientific carbon cycle with zero emission of CO2. Thus, the efficacy of environmental protection via solving the problem of CO2 greenhouse effect is achieved, so as to grasp of the “Right of Carbon Emission Trading” issues.
Remark	United States Patent Application 20120115067 Link

ID=169

SrCo1−xSbxO3−δ cathode materials prepared by Pechini method for solid oxide fuel cell applications

Authors	Sea-Fue Wang, Hsi-Chuan Lu, Yung-Fu Hsu, Chien-Chung Huang, Chun-Ting Yeh
Source	Ceramics International Volume: 38, Issue: 7, Pages: 5941–5947 Time of Publication: 2012-09
Abstract	In this study, SrCo1−ySbyO3−δ powders were prepared by a modified Pechini method. According to the study results, the cubic Pm3m phase of the SrCo1−ySbyO3−δ ceramics was obtained as 10% of cobalt ions were substituted by antimony ions. Doping of Sb3+ ions appeared both to stabilize the Pm3m phase of the SrCo1−ySbyO3−δ ceramics and to enhance densification and retard grain growth. The coefficient of thermal expansion of the SrCo1−xSbxO3−δ ceramics increased with the content of the antimony ions, ranging from 10.17 to 15.37 ppm/°C at temperatures lower than the inflection point (ranging from 450 °C to 550 °C) and from 22.16 to 29.29 ppm/°C at higher temperatures. For the SrCo0.98Sb0.02O3−δ ceramic, electrical conductivity reached a maximum of 507 S/cm at 450 °C. The ohmic and polarization resistances of the single cell with the pure SrCo0.98Sb0.02O3−δ cathode at 700 °C read respectively 0.298 Ω cm2 and 0.560 Ω cm2. The single cell with the SrCo0.98Sb0.02O3−δ-SDC composite cathode appeared to reduce the impedances with the R0 and RP at 700 °C reading respectively 0.109 Ω cm2 and 0.127 Ω cm2. Without microstructure optimization and measured at 700 °C, the single cells with the pure SrCo0.98Sb0.02O3−δ cathode and the SrCo0.98Sb0.02O3−δ-SDC composite cathode, demonstrated maximum power densities of 0.100 W/cm2 and 0.487 W/cm2. Apparently, SrCo1−ySbyO3−δ is a potential cathode for use in IT-SOFCs.
Keywords	Solid oxide fuel cell; Cathode; Impedance; Cell performance
Remark	Available online 19 April 2012 Link

ID=166

Preparation and characterization of composite membranes based on sulfonated PEEK and AlPO4 for PEMFCs

Authors	Vijay Shankar Rangasamy, Savitha Thayumanasundaram, Niels De Greef, Jin Won Seo, Jean-Pierre Locquet
Source	Solid State Ionics Volume: 219, Pages: 83–89 Time of Publication: 2012-05
Abstract	Sulfonated poly(ether ether ketone) (PEEK) and their composites are considered one of the most promising alternatives for Nafion, the industry benchmark for electrolytic membranes in proton exchange membrane (PEM) fuel cells. In the present study, PEEK was non-homogeneously sulfonated using concentrated H2SO4 at different temperatures (room temperature, 60 °C, and 80 °C) and time durations (5, 7, 48, and 72 h). Composite membranes of SPEEK with different weight ratios of AlPO4 synthesized by sol–gel were also prepared. Depending on the degree of sulfonation (DS), the Ion Exchange Capacity (IEC) of the membranes varied from 1.06 to 2.9 meq g− 1. XRD results show the increasing amorphous nature of the membranes with increase in IEC and DS value. The water uptake of the membranes also increased with DS. Simultaneous TGA–FTIR measurement of the composite membranes showed better thermal stability compared to pure SPEEK membranes. The water uptake and proton conductivity of the composite SPEEK membranes were found to be lower than that of pure SPEEK membranes, while the composite membranes exhibited a better swelling behavior and mechanical stability than the pure SPEEK samples.
Keywords	Proton exchange membrane (PEM); Composite membranes; Sulfonated poly(etheretherketone) (SPEEK); Proton conductivity; Ion exchange capacity (IEC); Sol–gel
Remark	Link

ID=160

Sandvik Sanergy HT – A potential interconnect material for LaNbO4-based proton ceramic fuel cells

Authors	Anders Werner Bredvei Skilbred, Reidar Haugsrud
Source	Journal of Power Sources Volume: 206, Pages: 70–76 Time of Publication: 2012-05
Abstract	High temperature properties of Sandvik Sanergy HT have been studied to evaluate the alloy's suitability as an interconnect material for LaNbO4 based proton ceramic fuel cells (PCFCs). The thermal expansion behavior of the alloy deviates from LaNbO4 at higher temperatures which may be unfavorable, however the average values for the two materials over the whole temperature region are rather similar. The oxidation kinetics was parabolic and the rate constants were low at temperatures below 1000 °C. Accelerated oxidation was encountered after 300 h at 1000 °C revealing that the material may undergo severe degradation at sufficiently high temperatures. A complex oxide scale containing an inner layer of chromium oxide and an outer layer of various spinel phases containing chromium, manganese and iron was formed at all temperatures. As a consequence of high oxidation resistance and an oxide with relatively high electronic conductivity, the area specific resistance (ASR) of Sandvik Sanergy HT measured at 700 °C proved to be low.
Keywords	Proton ceramic fuel cell; Interconnect; Sandvik Sanergy HT; Oxidation kinetics; Thermal expansion; Area specific resistance
Remark	Link

ID=159

A novel perovskite-based proton conductor for solid oxide fuel cells

Authors	Ramya Hariharan, T.R.S. Prasanna, Prakash Gopalan
Source	Scripta Materialia Volume: 66, Issue: 9, Pages: 658–661 Time of Publication: 2012-05
Abstract	A perovskite-based electrolyte, Ca-substituted YAlO3, has been synthesized by the citrate gel process. The conductivity of Y0.9Ca0.1AlO3-δ has been studied by AC impedance spectroscopy in controlled atmospheres in the temperature range 300–800 °C. The material has been found to be a mixed conductor with dominant p-type electronic conduction at elevated temperatures and a combined protonic conduction below 600 °C in wet conditions. The H/D isotope effect on conductivity confirms the presence of protonic conductivity between 400 and 600 °C.
Keywords	Proton conduction; Electrical properties; Solid electrolyte; Perovskite oxide; Fuel cell materials
Remark	Link

ID=154

Influence of Microwave-Assisted Pechini Method on La0.80Sr0.20Ga0.83Mg0.17O3–δ Ionic Conductivity

Authors
Source	Fuel Cells Volume: 12, Issue: 1, Pages: 54–60 Time of Publication: 2012-02
Abstract	With the aim of investigating the microwave influence on the electrolyte material properties, La0.80Sr0.20Ga0.83Mg0.17O2.815 was prepared by both a conventional and a microwave-assisted sol–gel Pechini method. With respect to the conventional Pechini method (hereafter SGP), the microwave assisted process (hereafter MWA-SGP) guaranteed a faster procedure, reducing the time needed to remove the excess solvents to complete the polyesterification reaction from some days to a few hours. In fact, when a MWA-SGP method was used, powders having higher phase purity were obtained. The sintering process at 1,450 °C of the powders prepared by both methods yielded pellets with similar density values (≥92% of theoretical). Nevertheless, only by microwave-assisted process single-phase products were obtained and no secondary phases such as tetragonal LaSrGaO4 and LaSrGa3O7 were detected. These by-products have been demonstrated to be detrimental for conductivity. Indeed, pellets obtained by MWA-SGP method showed oxygen ionic conductivity values higher (about 30–40%) than those checked for SGP samples, thus demonstrating the important role of the microwave process on reducing time and costs and on improving the electrolyte properties.
Keywords	Ionic Conductivity;IT-SOFC;Microwave Processing;(Sr, Mg)-Doped LaGaO3;Sol–Gel
Remark	Link

ID=148

Fabrication and electrochemical properties of cathode-supported solid oxide fuel cells via slurry spin coating

Authors	Min Chen, Jing-Li Luo, Karl T. Chuang, Alan R. Sanger
Source	Electrochimica Acta Volume: 63, Pages: 277–286 Time of Publication: 2012-02
Abstract	A cathode-supported SOFC consisting of LSM (La0.8Sr0.2MnO3-δ) cathode supporter, LSM-Sm0.2Ce0.8O2-δ (SDC) cathode functional layer (CFL), yttria stabilized zirconia (YSZ)/SDC bi-layered electrolyte and Ni-YSZ anode layer was fabricated by a slurry spin coating technique. The influence of the porosity in both the CFL and cathode supporter on the electrochemical properties of the cells has been investigated. It was found that properly controlling the porosity in the CFL would improve the performance of the cells using O2 in the cathode side (O2-cells), with a maximum power density (MPD) value achieving as high as 0.58 W•cm−2 at 850 °C. However, this improvement is not so evident for the cells using air in the cathode side (air-cells). When increasing the porosity in the cathode-supporter, a significant increase of the power density for the air cells due to the decreasing Rconc,c(concentration polarization to the cell resistance) can be ascertained. In terms of our analysis on various electrochemical parameters, the Ract (activation polarization to the cell resistance) is assumed to be mainly responsible for the impedance arcs measured under the OCV condition, with a negligible Rconc,cvalue being able to be detected in our impedances. In this case, a significant decreasing size of the impedance arcs due to the increasing porosity in the cathode supporter would correspond to a decrease of the Ract values, which was proved to be induced by the decreasingRconc,c.
Keywords	Slurry spin coating; Cathode-supported SOFC; Concentration polarization; Activation polarization; Power density
Remark	Link

ID=142

Evaluation of the electrode/electrolyte contact quality in solid oxide fuel cells

Authors	Jacqueline Amanda Figueiredo dos Santos, Michel Kleitz, Tulio Matencio, Rosana Zacarias Domingues
Source	Electrochimica Acta Volume: 60, Pages: 224–229 Time of Publication: 2012-01
Abstract	Symmetrical cells have been prepared by depositing suspensions with different active powder concentrations (50% and 60% by weight respectively) of lanthanum strontium cobalt iron oxide (La0.6Sr0.4Co0.2Fe0.8O3-δ) on identical yttria stabilized zirconia pellets (LSCF/YSZ/LSCF). Their impedance characteristics are compared to that of a symmetrical cell with platinum electrodes deposited on a similar zirconia pellet (Pt/YSZ/Pt). The LSCF cells show different values of the electrolyte resistance. Referring to the electrolyte resistance obtained with the Pt cell and assuming that this value corresponds to almost perfect electrode/electrolyte contacts, it is possible to estimate the Effective Conducting Area (ECA) of the electrodes. The use of the ECA parameter allows a better comparison of the electrode polarizations.
Keywords	solid oxide fuel cells; porous electrodes; cathode
Remark	Link

ID=139

Effects of (LaSr)(CoFeCu)O3-δ Cathodes on the Characteristics of Intermediate Temperature Solid Oxide Fuel Cells

Authors	Sea-Fue Wang, Chun-Ting Yeh, Yuh-Ruey Wang, Yung-Fu Hsu
Source	Journal of Power Sources Volume: 201, Pages: 18–25 Time of Publication: 2012-03
Abstract	In this study, Cu2+ ions doped La0.6Sr0.4Co0.2Fe0.8O3−δ cathodes are prepared for use in solid oxide fuel cells (SOFCs). The maximum electrical conductivities of the La0.6Sr0.4Co0.2Fe0.7Cu0.1O3−δ (438 S cm−1) and the La0.6Sr0.4Co0.1Fe0.8Cu0.1O3−δ (340 S cm−1) discs are higher than that of the La0.6Sr0.4Co0.2Fe0.8O3−δ disc (LSCF; 81 S cm−1) sintered at 1100 °C. The substitution of Cu2+ over Fe3+ leads to a higher coefficients of thermal expansion (CTE), while the replacement of Co3+ by Cu2+ results in a lower CTE. Single cells with the La0.6Sr0.4Co0.2Fe0.8O3−δ, La0.6Sr0.4Co0.2Fe0.7Cu0.1O3−δ, and La0.6Sr0.4Co0.1Fe0.8Cu0.1O3−δ cathodes operating at 650 °C and 550 °C show similar ohmic resistance (R0) values while the polarization resistance (RP) values of the cells with the La0.6Sr0.4Co0.2Fe0.7Cu0.1O3−δ and a0.6Sr0.4Co0.1Fe0.8Cu0.1O3−δ cathodes are slightly lower than that of the single cell with the La0.6Sr0.4Co0.2Fe0.8O3−δ cathode, indicating that the Cu2+-doped LSCF cathode exhibits a greater electrochemical catalytic activity for oxygen reduction. Maximum power densities of the cells with the La0.6Sr0.4Co0.2Fe0.8O3−δ, La0.6Sr0.4Co0.2Fe0.7Cu0.1O3−δ, and La0.6Sr0.4Co0.1Fe0.8Cu0.1O3−δ cathodes operating at 700 °C read respectively 1.07, 1.15, and 1.24 W cm−2. It is evident that the doping of Cu2+ ions in LSCF is beneficial to the electrochemical performance of the cells.
Keywords	Solid oxide fuel cell; cathode; cathode; impedance; Cell performance
Remark	Link

ID=137

Effect of nano-grain size on the ionic conductivity of spark plasma sintered 8YSZ electrolyte

Authors	K. Rajeswari, M. Buchi Suresh, Dibyendu Chakravarty, Dibakar Das, Roy Johnson
Source	International Journal of Hydrogen Energy Volume: 37, Issue: 1, Pages: 511–517 Time of Publication: 2012-01
Abstract	Densification and micro-structural development of ultra fine 8 mol% yttria stabilized zirconia (8YSZ) nano powder were investigated systematically by varying the SPS sintering temperature at constant applied pressure of 50 MPa. A hundred fold decrease in average grain size ranging from 10 μm to 80 nm is observed on decreasing the SPS sintering temperature from 1200 °C to 1050 °C with >99% of theoretical densities. Impedance measurements on the samples indicated an enhancement in the ionic conductivity at 700 °C from 0.004 S/cm to 0.018 S/cm with decrease in grain size from 10 μm to 0.51 μm and a significant increase in conductivity from 0.018 S/cm to 0.068 S/cm on further reduction of grain size to 80 nm. A significant change in the grain-boundary conductivity is noticed on reducing the grain sizes to nano regime. The diverse microstructure with ultra fine grain size resulting from SPS at 1050 °C could contribute to the enhanced ionic conductivity, which is supported by the activation energy data.
Keywords	Solid oxide fuel cells; Electrolyte; Microstructure; Spark plasma sintering
Remark	Link

ID=134

Post-heat treatment pressure effect on performances of metal-supported solid oxide fuel cells fabricated by atmospheric plasma spraying

Authors	Chun-Huang Tsai, Chang-sing Hwang, Chun-Liang Chang, Jen-Feng Yu, Sheng-Hui Nien
Source	Journal of Power Sources Volume: 197, Pages: 145–153 Time of Publication: 2012-01
Abstract	The nickel metal-supported cells fabricated by atmospheric plasma spraying are post-heat treated in air at 960 °C for 2 h with different pressures. The current–voltage–power and AC impedance measurements show the prepared cell with an applied pressure of 450 g cm−2 in the post-heat treatment has a better electrochemical performance at test temperatures ≥ 650 °C. For test temperatures < 650 °C, the maximum power densities at 450 g cm−2 pressure are about the same as the maximum power densities at 1250 g cm−2 pressure. The SEM micrograph indicates that the cathode including the cathode interlayer and the cathode collector is the most porous region in the cell. AC impedance results show this cathode is the most sensitive part to the applied pressure in the post-heat treatment and the cell with 450 g cm−2 pressure has the smallest low frequency intercept R2 and the polarization resistance Rp at temperatures from 600 to 800 °C. The performance durability test of the cell post-heat treated at 450 g cm−2 pressure shows a degradation rate of 0.0087 mV h−1 or 0.0026 mW h−1 at 300 mA cm−2 constant current density and 750 °C test temperature.
Keywords	Atmospheric plasma spray; Solid oxide fuel cells; Metal-supported; Nanostructured
Remark	Link

ID=124

Lamellar Titanates: A Breakthrough in the Search for New Solid Oxide Fuel Cell Anode Materials Operating on Methane

Authors
Source	Advanced Energy Materials Volume: 1, Issue: 4, Pages: 573–576 Time of Publication: 2011-07
Abstract	Decreasing the dimensionality of the LaxSr1–xTiOmath image family structure from 3D to 2D by increasing the La content greatly enhances the electrochemical performance of the material as an SOFC anode. This is attested to by the strong decrease in the polarization resistance values deduced from the complex impedance spectra (Nyquist plot) recorded at 900 °C in H2/H2O(3%) on a symmetrical cell.
Keywords	Solid oxide fuel cells; Anode materials; Titanate; Methane
Remark	Link

ID=123

An ion-plasma technique for formation of anode-supported thin electrolyte films for IT-SOFC applications

Authors	N.S. Sochugov, A.A. Soloviev, A.V. Shipilova, V.P. Rotshtein
Source	International Journal of Hydrogen Energy Volume: 36, Issue: 9, Pages: 5550-5556 Time of Publication: 2011-05
Abstract	This paper describes a preparation method and structural and electrochemical properties of a thin bilayer anode-electrolyte structure for a solid oxide fuel cell operating at intermediate temperatures (IT-SOFC). Thin anode-supported yttria-stabilized zirconia electrolyte films were prepared by reactive magnetron sputtering of a Zr–Y target in an Ar–O2 atmosphere. Porous anode surfaces of IT-SOFCs were modified by a pulsed low-energy high-current electron beam prior to film deposition; the influence of this pretreatment on the performance of both the deposited films and a single cell was investigated. The optimal conditions of the pulsed electron beam pretreatment were obtained. For the electrolyte thickness about 2.5 μm and the value of gas permeability of the anode/electrolyte structure 1.01 × 10−7 mol m−2 s−1 Pa−1, the maximum power density achieved for a single cell at 800 °C and 650 °C was found to be 620 and 220 mW cm−2 in air, respectively.
Keywords	Solid oxide fuel cell; YSZ electrolyte; Magnetron sputtering; Surface modification of material; Pulsed electron beam treatment; Electrical performance

ID=122

Microwave-assisted synthesis of gadolinia-doped ceria powders for solid oxide fuel cells

Authors	A. Gondolini, E. Mercadelli, A. Sanson, S. Albonetti, L. Doubova and S. Boldrini
Source	Ceramics International Volume: 37, Issue: 4, Pages: 1423-1426 Time of Publication: 2011-05
Abstract	Gadolinia doped ceria (GDC) is an attractive electrolyte material for intermediate temperature solid oxide fuel cells (IT-SOFCs) for its high ionic conductivity at low temperature (500–700 °C). A number of different methods are currently used to prepare nano-sized doped-ceria powder. Among the others, precipitation in solution remains the best method to obtain well-dispersed particles of controlled properties. In this work, nanocrystalline Ce1−xGdxO2−δ (GDC) particles were produced by polyol microwave assisted method in very mild conditions (170 °C, 2 h, 1 atm). The as-synthesized powder showed good sinterability and ionic conductivity comparable to the ones of the corresponding nanometric commercial GDC.
Keywords	GDC; Microwave heating; Polyol method; IT-SOFC

ID=121

Solid oxide fuel cells with Sm0.2Ce0.8O2−δ electrolyte film deposited by novel aerosol deposition method

Authors	Sea-Fue Wang, Yung-Fu Hsu, Chih-Hao Wang and Chin-Ting Yeh
Source	Journal of Power Sources Volume: 196, Issue: 11, Pages: 5064-5069 Time of Publication: 2011-06
Abstract	In this study, dense electrolyte ceramic Sm0.2Ce0.8O2−δ (SDC) thin films are successfully deposited on NiO-SDC anode substrate by aerosol deposition (AD) with oxygen as the carrier gas at the substrate temperature ranging from room temperature to 300 °C. To remove the effect of humidity on the starting powders, this study found that, in depositing SDC films, having the starting powders preheat-treated at 200 °C helped generate a smooth and dense layer, though a lower deposition rate was achieved. At a deposition time of 22 min, SDC films with a uniform thickness of 1.5 μm and grain sizes of ≈67 nm are obtained. SOFC single cells are then built by screen printing a LSCF cathode on the anode-supported substrates with SDC electrolyte. The cross-sectional SEM micrographs exhibit highly dense, granular, and crack-free microstructures. The open circuit voltages (OCV) of the single cells decrease with the rise in temperature, dropping from 0.81 V at 500 °C to 0.59 V at 700 °C. Maximum power densities (MPD) decline with decreasing operating temperature from 0.34 to 0.01 W cm−2 due to the increase of the R0 and RP of the single cells. The electrochemical results testify to the fine quality of SDC films as well as illustrate the electrolyte thickness effect and the effect of mixed ionic and electronic conduction of the SDC electrolyte in the reducing atmosphere.
Keywords

ID=119

Fabrication and Characterization of Anode-Supported BaIn0.3Ti0.7O2.85 Thin Electrolyte for Solid Oxide Fuel Cell

Authors	M. Rieu, P. K. Patro, T. Delahaye*, E. Bouyer
Source	International Journal of Applied Ceramic Technology Article first published online: 28 MAR 2011 Time of Publication: 2011-03
Abstract	BaIn0.3Ti0.7O2.85 (BIT07) is a promising electrolyte for solid oxide fuel cells, due to its chemical compatibility with most of the cathode electrode material such as LSM and Ln2NiO4. The present work is aimed on the fabrication of anode-supported half cells with thin BIT07 electrolyte. For this, Ni-8YSZ cermet was chosen due to its excellent mechanical and electrochemical properties, in addition to its low cost. The NiO–8YSZ anode support was prepared by tape casting, and for this, an organic slurry formulation was optimized. The BIT07 electrolyte thin film was deposited through screen printing on the green anode. The formulation of the ink was optimized, and sintering at 1350°C for 3 h led to a dense electrolyte with controlled thickness varying from 2 to 12 μm. Further, the cermet electrode still had a homogeneous microstructure with well-defined anode/electrolyte interface. The electrode ASR was about 0.5 Ω cm2 and was stable over 500 h at 800°C under H2–3% H2O. The fabrications of half cells were successfully scaled up to 100 mm × 100 mm retaining the dimensional control and without any surface defects.

ID=114

Synthesis and characterization of Ca-substituted YAlO3 by pechini route for solid oxide fuel cells

Authors	Ramya Hariharan, Prakash Gopalan
Source	Solid State Sciences Volume: 13, Issue: 1, Pages: 168-174 Time of Publication: 2011-01
Abstract	The high operating temperature requirement of solid oxide fuel cells demands electrolyte materials stable at temperatures around 800 °C. The perovskite material YAlO3, with yttrium ion on the A-site and the aluminium ion on the B-site is being investigated as an electrolyte for solid oxide fuel cells. This work investigates the structure and electrical conductivity of undoped and Ca-doped YAlO3 compositions that has been synthesized by the Pechini route. The samples have been investigated by X-ray diffraction studies. The electrical conductivity studies have been performed using a.c impedance spectroscopy in the range 200–800 °C in air. The doped YAlO3 of composition x = 0.1 exhibits a total conductivity of about 2.2 mS/cm at 800 °C. The microstructural evaluation of the samples has been conducted by scanning electron microscopy coupled with energy dispersive spectrum analysis.

ID=107

Yttria-stabilized zirconia thin film electrolyte produced by RF sputtering for solid oxide fuel cell applications

Authors	Federico Smeacetto, Milena Salvo, Lakshmi Chandru Ajitdoss, Sergio Perero, Tomasz Moskalewicz, Stefano Boldrini, Lioudmila Doubova and Monica Ferraris
Source	Materials Letters Volume: 64, Issue: 22, Pages: 2450-2453 Time of Publication: 2010-11
Abstract	Thin film (40–600 nm) yttria-stabilized zirconia (YSZ) electrolytes for solid oxide fuel cells (SOFC) were deposited on NiO-YSZ anodes and fused silica substrates by RF sputtering, using low applied power without the use of post deposition annealing heat treatment. YSZ film showed a nanocrystalline structure and consisted of the Zr.85Y.15O1.93 (fcc) phase. The film was dense and the YSZ/anode interface was continuous and crack free. According to preliminary in-plane conductivity measurements (temperature range 550–750 °C) on the YSZ film, the activation energy for ionic conduction was found to be 1.18 ± 0.01 eV.
Keywords	Thin films; Ceramics; Microstructure; Nanomaterials

ID=105

Scandium stabilized zirconium thin films formation by e-beam technique

Authors	Darius Virbukas, Giedrius Laukaitis, Julius Dudonis, Oresta Katkauskė and Darius Milčius
Source	Solid State Ionics Volume: 184, Issue: 1, Pages: 10–13 Time of Publication: 2011-03
Abstract	Scandiumstabilizedzirconium (10ScSZ) thin ceramic films were deposited by e-beam evaporation of (ZrO2)0.90(Sc2O3)0.10 micro powder (particle size 0.5 ÷ 0.7 μm). The influence of deposition rate on formed thinfilms microstructure and electrical properties was studied. 10ScSZ thinfilms were deposited on two types of different substrates: optical quartz (SiO2) and Alloy-600 (Fe–Ni–Cr) substrates. Deposition rate was changed from 2 to 16 Å/s to test its influence on thinfilmformation and its properties. The microstructure of formed 10ScSZ thin ceramic films was studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Electrical parameters of formed thin ceramics were investigated in the frequency range from 0.1 Hz to 1.0 MHz (in temperature range from 473 to 873 K). The ionic conductivity of the deposited electrolyte 10ScSZ thinfilms was determined by impedance spectroscopy. It was determined that the deposition rate (in range from 2 to 16 Å/s) has influence on crystallite size. It increases by increasing the deposition rate from 18.4 to 26.9 nm. The XRD measurements show that the formed 10ScSZ thinfilms do not repeat the crystallographic phase of the initial evaporated powder material—it is changes from rhombohedra (initial powder) to cubic (the formed thinfilms).
Keywords	Scandium stabilized zirconium (ScSZ); Ionic conductivity; Electron beam deposition; Solid oxide fuel cells (SOFC)
Remark	Link

ID=98

Development of an In Situ Surface Deformation and Temperature Measurement Technique for a Solid Oxide Fuel Cell Button Cell

Authors	Huang Guo, Gulfam Iqbal, Bruce S. Kang
Source	International Journal of Applied Ceramic Technology Volume: 7, Issue: 1, January/February, Pages: 55-62 Time of Publication: 2010-01
Abstract	A novel experimental technique is developed to measure the in situ surface deformation and temperature of a solid oxide fuel cell (SOFC) anode surface along with the cell electrochemical performance. The experimental setup consists of a NexTech ProboStat™ SOFC button cell test apparatus integrated with a Sagnac interferometric optical method and an infrared sensor for in situ surface deformation and temperature measurements, respectively. The button cell is fed with hydrogen or simulated coal syngas under SOFC operating conditions. The surface deformation is measured over time to estimate the anode structural degradation. The cell surface transient temperature is also monitored with different applied current densities under hydrogen and simulated coal syngas. The experimental results are useful to validate and develop SOFC structural durability and electrochemical models.

ID=96

Correlation between microstructure and electrical conductivity in composite electrolytes containing Gd-doped ceria and Gd-doped barium cerate

Authors	Mudrika Khandelwal, A. Venkatasubramanian, T.R.S. Prasanna and P. Gopalan
Source	Journal of the European Ceramic Society Volume: 31, Issue: 4, Pages: 559–568 Time of Publication: 2011-04
	Composite; Ceria; Impedance spectroscopy; Electrical conductivity; Fuel cell
Remark	Link

ID=94

The properties of scandium and cerium stabilized zirconium thin films formed by e-beam technique

Authors	Darius Virbukas, Giedrius Laukaitis, Julius Dudonis and Darius Milčius
Source	Solid State Ionics Volume: 188, Issue: 1, Pages: 46–49 Time of Publication: 2011-04
Abstract	Scandium and ceriumstabilizedzirconium (10Sc1CeSZ) thin ceramic films were formed evaporating (ZrO2)0.89(CeO2)0.01(Sc2O3)0.10 micro powder using e-beam evaporation technique. The influence of deposition rate on formedthinfilms electrical properties and microstructure was studied. 10Sc1CeSZ thinfilms were deposited on two types of different substrates: optical quartz (SiO2) and Alloy 600 (Fe–Ni–Cr). Deposition rate was changed from 2 to 16 Å/s to understand its influence on thinfilm formation and other properties. The formed 10Sc1CeSZ thinfilms keep the cubic crystal structure as the initial evaporated powder material but change the main crystallographic peak from (111) to (200) for both types of substrate and used deposition rates. It was determined that the crystallites size increases from 19.0 to 24.9 nm and from 15.6 to 19.9 nm on optical quartz and Alloy 600 respectively by increasing the deposition rate (in range from 2 to 16 Å/s). The thinfilm density decreases by increasing the deposition rate. The ionic conductivity of 10Sc1CeSZ thinfilms was determined by impedance spectroscopy in the frequency range from 0.1 Hz to 1.0 MHz in temperature range from 473 K to 873 K. The best ionic conductivity σtot = 4.91 · 10− 2 Sm− 1 at 873 K temperature and the lowest value of activation energy ΔEa = 0.88 eV were found for 10Sc1CeSZ thinfilmsformed at 4 Å/s deposition rate.
Keywords	Scandium and cerium stabilized zirconium (10Sc1CeSZ); Electron beam deposition; Solid oxide fuel cells (SOFC); Ionic conductivity
Remark	Link

ID=93

Ethanol internal steam reforming in intermediate temperature solid oxide fuel cell

Authors	Stefan Diethelm, Jan Van Herle
Source	Journal of Power Sources Volume: 196, Issue: 17, Pages: 7355–7362 Time of Publication: 2011-09
Abstract	This study investigates the performance of a standard Ni–YSZ anode supported cell under ethanolsteamreforming operating conditions. Therefore, the fuelcell was directly operated with a steam/ethanol mixture (3 to 1 molar). Other gas mixtures were also used for comparison to check the conversion of ethanol and of reformate gases (H2, CO) in the fuelcell. The electrochemical properties of the fuelcell fed with four different fuel compositions were characterized between 710 and 860 °C by I–V and EIS measurements at OCV and under polarization. In order to elucidate the limiting processes, impedance spectra obtained with different gas compositions were compared using the derivative of the real part of the impedance with respect of the natural logarithm of the frequency. Results show that internalsteamreforming of ethanol takes place significantly on Ni–YSZ anode only above 760 °C. Comparisons of results obtained with reformate gas showed that the electrochemical cell performance is dominated by the conversion of hydrogen. The conversion of CO also occurs either directly or indirectly through the water–gas shift reaction but has a significant impact on the electrochemical performance only above 760 °C.
Keywords	SOFC; Ni–YSZ anode; Ethanol; Internal reforming; Coking; Impedance spectroscopy
Remark	Link

ID=91

Proton Conductivity in Mixed B-Site Doped Perovskite Oxide BaZr0.5In0.25Yb0.25O3−delta

Authors	Istaq Ahmed,1,2 Francis G. Kinyanjui,1 Seikh M. H. Rahman,1 Patrick Steegstra,3 Sten G. Eriksson,1 and Elisabet Ahlberg3
Source	J. Electrochem. Soc. Volume: Volume 157, Issue: Issue 12, Pages: B1819-B182 Time of Publication: 2010-12
Abstract	A wet chemical route was used to prepare the oxygen deficient codoped perovskite oxide BaZr0.5In0.25Yb0.25O3−. Analysis of X-ray powder diffraction data showed that the sample belongs to the cubic crystal system with space group Pmm. Dynamic thermogravimetric (TG) analysis confirmed complete filling of oxygen vacancies (V) by protonic defects (OH) during the hydration process. The proton conductivity was investigated by impedance spectroscopy. The bulk and total conductivities of prehydrated BaZr0.5In0.25Yb0.25O3− were found to be 8.5×10−4 and 2.2×10−5 S cm−1, respectively, at 300°C. The total conductivity in the codoped perovskite oxide was higher compared to that of the respective single doped perovskite oxides with the same doping level. The bulk and grain-boundary mobility and diffusion coefficients of protons were calculated at 200°C using impedance and TG data to obtain the conductivity and proton concentration, respectively. The high bulk diffusivity (2.3×10−7 cm2 s−1) was obtained which indicates that the protons are more free to move in the heavily doped matrix compared to the lightly doped systems where trapping of protons occurs.
Keywords	barium compounds, proton exchange membrane fuel cells, thermal analysis, vacancies (crystal), X-ray diffraction, zirconium compounds
Remark	Link

ID=74

Ce0.9Sr0.1VOx (x = 3, 4) as anode materials for H2S-containing CH4 fueled solid oxide fuel cells

Authors	Nemanja Danilovic, Jing-Li Luo, Karl T. Chuang and Alan R. Sanger
Source	Journal of Power Sources Volume: 192, Issue: 2, Pages: 247-257 Time of Publication: 2009

ID=72

Effect of substitution with Cr3+ and addition of Ni on the physical and electrochemical properties of Ce0.9Sr0.1VO3 as a H2S-active anode for solid oxide fuel cells

Authors	N. Danilovic, J.L. Luo, K. T. Chuang and A. R. Sanger
Source	Journal of Power Sources Volume: 194, Issue: 1, Pages: 252-262 Time of Publication: 2009

ID=69

Synthesis and characterization of nanocrystalline Ni–YSZ cermet anode for SOFC

Author	T. Priyatham and Ranjit Bauri
Source	Materials Characterization Volume: 61, Issue: 1, Pages: 54-58 Time of Publication: 2010-01
Abstract	Ni–YSZ cermet anode has been synthesized in one step using a simple and cost effective combustion synthesis process. The processed powder of NiO–YSZ is found to be nanocrystalline with crystallite sizes of 29 and 22 nm for NiO and YSZ respectively by X-ray diffraction and transmission electron microscopy analysis. X-ray diffraction analysis also shows that the precursor salts are converted to highly crystalline phases of NiO and YSZ (8 mol% Y2O3) without any intermediate calcination step and no undesirable phases are present. Comparison with the X-ray diffraction pattern of a commercial YSZ sample shows that the process is also effective in maintaining a close compositional control. The microstructure of the sintered and reduced sample shows a well defined network of pores which is necessary for the effective functioning of the anode. The electrical conductivity as a function of temperature shows metallic behavior.
Keywords	Ni–YSZ anode; Combustion synthesis; Nanocrystalline cermet; Microstructure

ID=63

Ceria and copper/ceria functional coatings for electrochemical applications: Materials preparation and characterization

Authors	J. Melnik, X.Z. Fu, J.L. Luo, A.R. Sanger, K.T. Chuang, Q.M. Yang
Source	Journal of Power Sources Volume: 195, Issue: 8, Pages: 2189-2195 Time of Publication: 2010
Abstract	Following preliminary investigations, two electrodeposition techniques (electrophoretic and electrolytic) were selected and adapted for deposition of doped ceria ceramic and copper/doped ceria composite coatings on Ni substrates (foil and foam). The copper/doped ceria composites have potential value as protective functional coatings for current collectors in electrochemical cells including solid oxide fuel sells (SOFC). The doped ceria ceramic coating has potential application as a porous matrix for anodes of SOFCs operating on syngas, sour gas, or hydrocarbons.
Keywords	Electrodeposition; Coating; Ceramics; Composite; Fuel cell

ID=58

GdBaCo2O5+x layered perovskite as an intermediate temperature solid oxide fuel cell cathode

Authors	Tarancon, A. / Morata, A. / Dezanneau, G. / Skinner, S.J. / Kilner, J.A. / Estrade, S. / Hernandez-Ramirez, F. / Morante, J.R.
Source	as Pages: p.255-263 Time of Publication: 2007

ID=52

Plasma sprayed metal supported YSZ/Ni–LSGM–LSCF ITSOFC with nanostructured anode

Authors	Hwang, C., Tsai, C.H., Lo, C.H., Sun, C.H.
Source	Journal of Power Sources, 180 (1), Pages: p.132-142 Time of Publication: 2008

ID=39

Bismuth ruthenate based pyrochlores for IT-SOFC applications

Authors	Zhong, Zhimin
Source	Electrochemical and Solid-State Letters Volume: 9, Issue: 4, Pages: A215-219 Time of Publication: 2006

ID=23

"Spinel and perovskite functional layers between Plansee metallic interconnect (Cr-5wt%Fe-1wt%Y2O3) and ceramic (La0.85Sr0.15)0.91MnO3 cathode materials for solid oxide fuel cells"

Authors	Y. Larring, T. Norby
Source	J. Electrochem. Soc. Volume: 147 , Issue: 9, Pages: 3251-3256 Time of Publication: 2000
Remark	Disk samples of alloy + LSM layer

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The Role of Strain in Proton Conduction in Multi-Oriented BaZr0.9Y0.1O3−δ Thin Film

A New Electroactive and Stable Electrode Based on Praseodymium Molybdate for Symmetrical SOFCs

Development and characterization of highly stable electrode inks for low-temperature ceramic fuel cells

Effects of Ni-NCAL and Ni–Ag electrodes on the cell performances of low-temperature solid oxide fuel cells with Sm0.2Ce0·8O2-δ electrolyte at various temperatures

Magnetron sputtered LSC-GDC composite cathode interlayer for intermediate-temperature solid oxide fuel cells

Nanostructured La0.75Sr0.25Cr0.5Mn0.5O3–Ce0.8Sm0.2O2 Heterointerfaces as All-Ceramic Functional Layers for Solid Oxide Fuel Cell Applications

Effects of LiNi0.8Co0.15Al0.05O2 electrodes on the conduction mechanism of Sm0.2Ce0.8O2−δ electrolyte and performance of low-temperature solid oxide fuel cells

Efficiencies of cobalt- and copper-based coatings applied by different deposition processes for applications in intermediate-temperature solid oxide fuel cells

On the mechanism of Mn(II)-doping in Scandia stabilized zirconia electrolytes

Impedance spectroscopy study of Au electrodes on Gd-doped CeO2 (GDC) – Molten Li2CO3+Na2CO3 (LNC) composite electrolytes

Advanced metal oxide infiltrated electrodes for boosting the performance of solid oxide cells

High-performance anode-supported solid oxide fuel cells with co-fired Sm0.2Ce0.8O2-δ/La0.8Sr0.2Ga0.8Mg0.2O3−δ/Sm0.2Ce0.8O2-δ sandwiched electrolyte

Synthesis, structure and ionic conductivity of nanocrystalline Ce1−xLaxO2−δ as an electrolyte for intermediate temperature solid oxide fuel cells

Unlocking bulk and surface oxygen transport properties of mixed oxide-ion and electron conducting membranes with combined oxygen permeation cell and oxygen probe method

Electrochemical Performance of SrWO4 Electrolyte for SOFC

Anode-supported solid oxide fuel cells with multilayer LSC/CGO/LSC cathode

Structural and Electrochemical Properties of Scandia Alumina Stabilized Zirconia Thin Films

Preparation of NdBaCo2O5+δ–Ce0.9Gd0.1O1.95 composite cathode by in situ sol-mixing method and its high-temperature electrochemical properties

Microstructure and electrochemical behavior of layered cathodes for molten carbonate fuel cell

Preparation and characterization of (La,Ca,Sr)(Fe,Co)O3-d cathodes for solid oxide fuel cells

The Effect of Thin Functional Electrode Layers on Characteristics of Intermediate Temperature Solid Oxide Fuel Cell

Fused filament fabrication for anode supported SOFC development: Towards advanced, scalable and cost-competitive energetic systems

The performance of intermediate temperature solid oxide fuel cells with sputter deposited La1-xSrxCoO3 interlayer

Comparative investigation on the functional properties of alkaline earth metal (Ca, Ba, Sr) doped Nd2NiO4+δ oxygen electrode material for SOFC applications

Synthesis and processing of SOFC components for the fabrication and characterization of anode supported cells

Increasing the thermal expansion of proton conducting Y-doped BaZrO3 by Sr and Ce substitution

Reversible fuel electrode supported solid oxide cells fabricated by aqueous multilayered tape casting

Strategies to Mitigate the Degradation of Stainless-SteelInterconnects Used in Solid Oxide Fuel Cells

Crystal structures and proton transport properties of Sr2(Ti1-xMx)O4-δ (M = Fe, Al)

Structural characterization and electrical/electrochemical studies of Nd1-xBaxCo1-y(Fe, Ti)y O3-δ (0 ≤ x ≤ 0.3, y = 0, 0.2) materials as cathode for SOFCs application

Effect of the Complexing Agent in the Pechini Method on the Structural and Electrical Properties of an Ionic Conductor of Formula La1−xSrxAlO3−δ (x = 0, 0.05, 0.1, 0.15)

In-situ Ni exsolution from NiTiO3 as potential anode for solid oxide fuel cells

Studying the Effects of Siloxanes on Solid Oxide Fuel Cell Performance

High ionic conductivity dysprosium and tantalum Co-doped bismuth oxide electrolyte for low-temperature SOFCs

A CO2-Tolerant Perovskite Oxide with High Oxide Ion and Electronic Conductivity

Long-term (4 year) degradation behavior of coated stainless steel 441 used for solid oxide fuel cell interconnect applications

Intriguing electrochemistry in low-temperature single layer ceramic fuel cells based on CuFe2O4

Mn-rich SmBaCo0.5Mn1.5O5+δ double perovskite cathode material for SOFCs

Microstructural and compositional optimization of La0.5Ba0.5CoO3−δ — BaZr1−zYzO3−δ (z=0,0.05 and 0.1) nanocomposite cathodes for protonic ceramic fuel cells

Fabrication and encapsulation of micro-SOFCs

Synthesis and Study of (Sr,La)2FeCo0.5Mo0.5O6 − δ Oxides with Double Perovskite Structure

Influence of Lanthanum Doping on Structural and Electrical/Electrochemical Properties of Double Perovskite Sr2CoMoO6 as Anode Materials for Intermediate-Temperature Solid Oxide Fuel Cells

Scheelite type Sr1−xBaxWO4 (x = 0.1, 0.2, 0.3) for possible application in Solid Oxide Fuel Cell electrolytes

Inkjet Printing Functionalization of SOFC LSCF Cathodes

Processing of high performance composite cathodes for protonic ceramic fuel cells by exsolution

Optimization of laser-patterned YSZ-LSM composite cathode-electrolyte interfaces for solid oxide fuel cells

SOFC cathodic layers using wet powder spraying technique with self synthesized nanopowders

Versatile Application of Redox Processes for REBaCoMnO5+δ (RE: La, Pr, Nd, Sm, Gd, and Y) Oxides

Effect of magnetron sputtered anode functional layer on the anode-supported solid oxide fuel cell performance

Effects of calcium doping to oxygen reduction activity on Pr2-xCaxNiMnO6 cathode

Effect of B-site doping on electrical conductivity of YAlO3 based electrolytes for solid oxide fuel cells

Dy doped SrTiO3: A promising anodic material in solid oxide fuel cells

Wide bandgap oxides for low-temperature single-layered nanocomposite fuel cell

An operando calorimeter for high temperature electrochemical cells

A novel anode for solid oxide fuel cells prepared from phase conversion of La0.3Sr0.7Fe0.7Cr0.3O3-δ perovskite under humid hydrogen

Assessment of layered La2-x(Sr,Ba)xCuO4-δ oxides as potential cathode materials for SOFCs

Optimization and Electrochemical Properties of Double Perovskite NdBaCo2O6–δ ·LaBaCo2O5+δ as Cathode Material for Solid Oxide Fuel Cell

Electrochemical and degradation study of Sr0.6Na0.4SiO3-δ

Novel ReBaCo1.5Mn0.5O5+δ (Re: La, Pr, Nd, Sm, Gd and Y) perovskite oxide: influence of manganese doping on the crystal structure, oxygen nonstoichiometry, thermal expansion, transport properties, and application as a cathode material in solid oxide f

High performance ceramic nanocomposite fuel cells utilizing LiNiCuZn-oxide anode based on slurry method

Enhanced Performance of Gadolinia-Doped Ceria Diffusion Barrier Layers Fabricated by Pulsed Laser Deposition for Large-Area Solid Oxide Fuel Cells

Solid oxide fuel cells incorporating doped lanthanum gallate films deposited by radio-frequency magnetron sputtering at various Ar/O2 ratios and annealing conditions

Lanthanum doped strontium titanate - ceria anodes: deconvolution of impedance spectra and relationship with composition and microstructure

Performance evaluation of Mn and Fe doped SrCo 0.9 Nb 0.1 O 3-δ cathode for IT-SOFC application

Does the conductivity of interconnect coatings matter for solid oxide fuel cell applications?

Amorphous-cathode-route towards low temperature SOFC

Co-deficient PrBaCo2−xO6−δ perovskites as cathode materials for intermediate-temperature solid oxide fuel cells: Enhanced electrochemical performance and oxygen reduction kinetics

Deposition of nickel oxide-yttria stabilized zirconia thin films by reactive magnetron sputtering

Solid oxide fuel cells with apatite-type lanthanum silicate-based electrolyte films deposited by radio frequency magnetron sputtering

Electrical conductivity of NiMo–based double perovskites under SOFC anodic conditions

Effect of sintering temperature on the performance of composite La0.6Sr0.4Co0.2Fe0.8O3–Ce0.9Gd0.1O2 cathode for solid oxide fuel cells

Structural and electrochemical characterization of BaCe0.7Zr0.2Y0.05Zn0.05O3 as an electrolyte for SOFC-H

Fabrication and characterization of La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF)-Ce0.9Gd0.1O1.95 (GDC) composite thick film for anode supported solid oxide fuel cells