Co/Fe oxide and Ce0.8Gd0.2O2-delta composite interlayer for solid oxide electrolysis cell

A composite interlayer comprised of gadolinia doped ceria (GDC) and Co/Fe oxide was prepared and investigated for solid oxide electrolysis cell with yttrium stabilized zirconia (YSZ) electrolyte and La0.6Sr0.4Co0.2Fe0.8O3-delta(LSCF) anode. The interlayer was constructed of a base layer of GDC and a top layer of discrete Co3O4/FeCo2O4 particles. The presence of the GDC layer drastically alleviated the undesired reactions between LSCF and YSZ, and the presence of Co/Fe oxide led to further performance improvement. At 800 degrees C and 45% humidity, the cell with 70% Co/Fe-GDC interlayer achieved 0.98 A/cm(2) at 1.18 V, 14% higher than the cell without Co/Fe oxide. Electrochemical impedance spectroscopy (EIS) revealed that with higher Co/Fe content, both the ohmic resistance and the polarization resistance of the cell were reduced. It is suggested that Co/Fe oxide can react with the Sr species segregated from LSCF and Sr1-x(Co,Fe)O3-delta, a compound with high catalytic activity and electronic conductivity. The Sr-capturing ability of Co/Fe oxide in combination with the Sr-blocking ability of GDC layer can effectively suppress the undesired reaction between LSCF and YSZ, and consequently improve the cell performance. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved

Co-synthesized Y-stabilized Bi2O3 and Sr-substituted LaMnO3 composite anode for high performance solid oxide electrolysis cell

In this study we report a nano-composite anode comprised of Y-stabilized Bi2O3 (YSB) and Sr-substituted LaMnO3 (LSM) for solid oxide electrolysis cell (SOEC). The composite powder with primary particle size ranging from 20 to 80 nm is co-synthesized via a simple citric-nitrate combustion method. X-ray diffraction examination confirms cubic fluorite YSB and rhombohedral perovskite LSM as the main phases in the composite. Temperature programmed O-2 desorption identifies remarkable low temperature desorption at 330 degrees C. Similarly, temperature programmed H-2 reduction reveals strong reduction at 385 degrees C. The facile oxygen evolution on YSB-LSM may result from the increased amount of oxygen vacancies and improved oxygen ion mobility. A cell employing YSB-LSM composite anode achieves current density of -1.52 A cm(-2) at 800 degrees C and 1.28 V, 50% higher than conventional LSM-YSZ cell. Impedance results and analysis of distribution of relaxation times indicate that the rate-determining anode processes are effectively accelerated on YSB-LSM. The activation energy for oxygen evolution reaction on YSB-LSM is reduced to 0.65 eV, notably lower than on LSM-YSZ (1.29 eV). The high performance of YSB-LSM composite anode is attributed to the fast ion decorporation on YSB, the facile O-2 formation on LSM, and the abundant phase boundaries that facilitate the two processes. (C) 2016 Elsevier B.V. All rights reserved

Ce0.7Bi0.3O1.85-(La0.8Sr0.2)(0.9)MnO3-Y0.16Zr0.84O1.(92) ternary cathodes for low temperature solid oxide fuel cells

The ternary cathodes of Ce0.7Bi0.3O1.85-(La0.8Sr0.2)(0.9)MnO3-Y0.16Zr0.84O1.92 (BDC-LSM-YSZ) are fabricated through infiltration for low temperature solid oxide fuel cells. The infiltrated BDC particles are 10-20 nm in size and cover on LSM and YSZ particles. The 10 wt% and 20 wt% BDC-LSM-YSZ samples show a large peak for the desorption of surface oxygen species and a large peak for the evolution of lattice oxygen, reflecting their good redox property. 0.1BDC-LSM-YSZ cell and 0.2BDC-LSM-YSZ cell give the power density at 0.6 V of 387.8 and 521.7 mWcm(-2) at 600 degrees C, which is 3.7 and 4.9 times higher than that of LSM-YSZ cell, respectively. 0.1BDC-LSM-YSZ cell and 0.2BDC-LSM-YSZ cell exhibit low ohmic resistance and low total polarization resistance. The DRT analysis reveals that charge transfer reaction and surface diffusion are greatly accelerated on the BDC-LSM-YSZ cathodes. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved

Activity and Stability of (Pr1-xNdx)(2)NiO4 as Cathodes for Solid Oxide Fuel Cells

Single phase (Pr1-xNdx)(2)NiO4 cathode powders (x = 0, 0.25, 0.50, 0.75, and 1.0) were synthesized via a glycine-nitrate combustion and high temperature calcination. Anode supported cells were used to investigate the cathode property. A reproducible performance, within 9% for each cathode composition, was observed providing a wealth of data for quantitative studies. Area specific resistance analysis and i-V measurements between 650 and 850 degrees C showed a decrease in the cell performance with increasing Nd content. Impedance spectrum analysis suggests that the decline in performance results from an increase in electrode polarization. While Pr2NiO4 cells showed significant performance degradation of 6.40%/1,000 hours, the degradation rate for (Pr0.75Nd0.25)(2)NiO4 cells was reduced by an order of magnitude (0.56%/1,000 hours) with a 7% lower power output. Likewise, the cathodes with a higher Nd content showed further improvement in performance stability with a marginal degradation rate of 0.06%/1,000 hours. (C) The Author(s) 2016. Published by ECS. All rights reserved