Improvement of La0.8Sr0.2MnO3-δ Cathode Material for Solid Oxide Fuel Cells by Addition of YFe0.5Co0.5O3

The high efficiency of solid oxide fuel cells with La0.8Sr0.2MnO3-delta (LSM) cathodes working in the range of 800-1000 degrees C, rapidly decreases below 800 degrees C. The goal of this study is to improve the properties of LSM cathodes working in the range of 500-800 degrees C by the addition of YFe0.5Co0.5O3 (YFC). Monophasic YFC is synthesized and sintered at 950 degrees C. Composite cathodes are prepared on Ce0.8Sm0.2O1.9 electrolyte disks using pastes containing YFC and LSM powders mixed in 0:1, 1:19, and 1:1 weight ratios denoted LSM, LSM1, and LSM1, respectively. X-ray diffraction patterns of tested composites reveal the presence of pure perovskite phases in samples sintered at 950 degrees C and the presence of Sr4Fe4O11, YMnO3, and La0.775Sr0.225MnO3.047 phases in samples sintered at 1100 degrees C. Electrochemical impedance spectroscopy reveals that polarization resistance increases from LSM1, by LSM, to LSM2. Differences in polarization resistance increase with decreasing operating temperatures because activation energy rises in the same order and equals to 1.33, 1.34, and 1.58 eV for LSM1, LSM, and LSM2, respectively. The lower polarization resistance of LSM1 electrodes is caused by the lower resistance associated with the charge transfer process.

Automated summary

This study aims to improve the performance of LSM cathodes in the low temperature range by adding YFC. The research found that the polarization resistance of the electrode increases with decreasing operating temperatures, and the LSM1 electrode has the lowest polarization resistance.