International Journal of Hydrogen Energy, Vol.43, No.27, 12368-12376, 2018
Performance and durability of an anode-supported solid oxide fuel cell with a PdO/ZrO2 engineered (La0.8Sr0.2)(0.95)MnO3-delta-(Y2O3)(0.08)(ZrO2)(0.92) composite cathode
PdO/ZrO2 co-infiltrated (La0.8Sr0.2)(0.95)MnO3-delta-((Y2O3)(0.08)(ZrO2)(0.92) (LSM-YSZ) composite cathode (PdO/ZrO2+LSM-YSZ), which adsorbs more oxygen than equal amount of PdO/ZrO2 and LSM-YSZ, is developed and used in Ni-YSZ anode-supported cells with YSZ electrolyte. The cells are investigated firstly at temperatures between 650 and 750 degrees C with H-2 as the fuel and air as the oxidant and then polarized at 750 degrees C under 400 mA cm(-2) for up to 235 h. The initial peak power density of the cell is in the range of 438-1207 mW cm(-2) at temperatures from 650 to 750 degrees C, corresponding to polarization resistance from 1.04 to 0.35 Omega cm(2). This result demonstrates a significant performance improvement over the cells with other kinds of LSM based cathode. The cell voltage at 750 degrees C under 400 mA cm(-2) decreases from initial 0.951 to 0.89 V after 170 h of current polarization and remains essentially stable to the end of current polarization. It is identified that the self-limited growth of PdO particles is responsible for the cell voltage decrease by reducing the length of triple phase boundary affecting the high frequency steps involved in oxygen reduction reaction in the cathode. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.
Keywords:Solid oxide fuel cell;Cell performance durability;Electrochemical impedance;Distribution of relaxation time;Palladium oxide particles growth