Oxygen Reduction at LSM-YSZ Cathodes Deposited on Anode-Supported Microtubular Solid Oxide Fuel Cells

Three-electrode methods were employed to evaluate the electrochemical activity of the oxygen reduction reaction (ORR) at lanthanum strontium manganite (LSM)-yttria stabilized zirconia (YSZ) composite cathodes deposited on the outer surface of microtubular, anode-supported, solid oxide fuel cells (mu SOFCs). The performance of these cathodes, deposited on the highly curved, electrophoretically deposited, thin YSZ electrolyte layers in the microtubular configuration, was compared against LSM-YSZ cathodes, deposited similarly and having the same microstructure, on 1 mm thick YSZ layers in standard SOFC planar cells. While the EIS response of the high and low frequency arcs for LSM-YSZ in the two-cell geometries differed somewhat, the total polarization resistance (R-P) and the ORR activation energy (similar to 125 kJ/mol) were similar. It was also demonstrated that LSM-YSZ cathode performance in the mu SOFC system can be further enhanced when the cell is sintered at 1150 vs 1100 degrees C.