Highly enhanced electrochemical performance of PrBa_(0.92)Co_2O_(5+δ) cathode by introducing Ba cationic-deficiency

摘要

An A-site Ba cation-deficient layered-perovskite oxide PrBa_(0.92)Co_2O_(5+δ) (PB0.92CO) was evaluated as a new cathode material for intermediate-temperature solid oxide fuel cells (IT-SOFCs). PB_(0.92)CO is chemically stable with Ce_(0.9)Gd_(0.1)O_(1.95) (GDC) electrolyte at temper-atures up to 1100 ℃. PB_(0.92)CO has conductivities of 580-195 S cm~1 at temperatures of 200-800 ℃ in air. Area specific resistances (ASR) of PB_(0.92)CO cathode on the GDC electrolyte layer range from 0.093 Ω cm~2 at 600 ℃ to 0.0068 Ω cm~2 at 800 ℃ with an activation energy of 1.05 eV. These ASR values are much lower than the results of the parent PrBa_(0.92)Co_2O_(5+δ) (PBCO) cathode, cation-doped PBCO cathodes and the PBCO-based composite cathodes. The preliminary results have demonstrated that PB_(0.92)CO has excellent electrochemical performances at temperatures of 600 ℃-800 ℃ and is a very promising cathode material for IT-SOFCs.