Electrochemical properties of B-site Ni doped layered perovskite cathodes for IT-SOFCs

Offering fast oxygen reduction kinetics and high electrical conductivities relative to those of ABO3-type perovskite oxides, layered perovskite cathode materials have received considerable attention for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this study, we have investigated the effects of Ni substitution for the Co site in SmBa0.5Sr0.5Co2O5+δ in terms of structural characteristics, electrical properties, and electrochemical performance of SmBa0.5Sr0.5Co2−xNixO5+δ (x = 0, 0.1, and 0.2) in relation to its application as an IT-SOFC cathode material. At the given temperature, the electrical conductivities of SmBa0.5Sr0.5Co2−xNixO5+δ (x = 0, 0.1, and 0.2) decrease with increasing Ni content. For x = 0.1, the lowest ASR value, 0.125 Ω cm2, and the highest single cell performance, 1.78 W cm−2 at 600 °C, are obtained.