Doped PrMnO3 Perovskite Oxide as a New Cathode of Solid Oxide Fuel Cells for Low Temperature Operation

Cathodic overpotentials of were studied for a new cathode of solid oxide fuel cell (SOFC). Cathodic overpotentials as well as the electrical conductivity strongly depended on the rare earth cations used for the A sites of perovskite oxide. Strontium doped exhibited the highest electrical conductivity among the examined perovskite oxide containing Mn for B sites. Moreover, overpotentials of Sr‐doped cathode maintained low values in spite of decreasing the operating temperature. Consequently, almost the same power density of SOFC with cathode can be obtained at about 100 K lower operating temperature by using Sr‐doped as the cathode. The overpotentials and electrical conductivity decreased and increased with increasing the amount of Sr dopant in , respectively, and the lowest overpotential was attained at . Comparing with oxide, the reactivity of with is much less than that of and furthermore, the matching of thermal expansion of with was satisfactorily high. Therefore, perovskite oxide of has a great possibility of the cathode materials for decreasing the operating temperature of solid oxide fuel cells.