Highly enhanced electrochemical performance of PrBa0.92Co2O5+δ cathode by introducing Ba cationic-deficiency

An A-site Ba cation-deficient layered-perovskite oxide PrBa0.92Co2O5+δ (PB0.92CO) was evaluated as a new cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). PB0.92CO is chemically stable with Ce0.9Gd0.1O1.95 (GDC) electrolyte at temperatures up to 1100 °C. PB0.92CO has conductivities of 580–195 S cm−1 at temperatures of 200–800 °C in air. Area specific resistances (ASR) of PB0.92CO cathode on the GDC electrolyte layer range from 0.093 Ω cm2 at 600 °C to 0.0068 Ω cm2 at 800 °C with an activation energy of 1.05 eV. These ASR values are much lower than the results of the parent PrBaCo2O5+δ (PBCO) cathode, cation-doped PBCO cathodes and the PBCO-based composite cathodes. The preliminary results have demonstrated that PB0.92CO has excellent electrochemical performances at temperatures of 600 °C–800 °C and is a very promising cathode material for IT-SOFCs. ► PB0.92CO is chemically stable with Ce0.9Gd0.1O1.95 electrolyte at temperatures up to 1100 °C. ► PB0.92CO has conductivities of 580–195 S cm−1 at 200–800 °C in air. ► ASR of PB0.92CO cathode ranges from 0.093 Ω cm2 at 600 °C to 0.0068 Ω cm2 at 800 °C.