Structure and properties of layered-perovskite LaBa1−xCo2O5+δ (x = 0-0.15) as intermediate-temperature cathode material

Phase structure, structure stability, electrical properties and catalytic activity for oxygen reduction reaction of the Ba-deficient layered-perovskite oxides LaBa1−xCo2O5+δ (LB1−xCO, x = 0.00-0.15) have been studied to determine their viability as cathode material of intermediate-temperature solid oxide fuel cells (IT-SOFCs). LB1−xCO had tetragonal layered-perovskite structure when calcined at 850 °C-1050 °C in air but transformed into cubic structure at higher temperatures. The LB1−xCO oxide exhibited lower electrical conductivities and decreased area-specific resistances (ASRs) on the Ce0.9Gd0.1O1.95 (GDC) electrolyte with higher Ba-deficiency content. Among the samples, the LB0.90CO (x = 0.10) oxide exhibited the best electrochemical performance with ASR values of 0.118 Ω cm2 at 600 °C and 0.023 Ω cm2 at 700 °C respectively, ∼40% lower than the results of the parent oxide (x = 0), demonstrating its promising application as cathode materials of IT-SOFCs.