Evaluation and optimization of SrCo0.9Ta0.1O3−δ perovskite as cathode for solid oxide fuel cells

The SrCo0.9Ta0.1O3-δ (SCT) perovskite-type oxide is synthesized by the conventional solid state reaction method and examined as an alternative cathode for intermediate temperature solid oxide fuel cells (IT-SOFCs). The electrical conductivity of SCT sample reaches 250–152 S cm−1 in the temperature range 600–800 °C. SCT exhibits good chemical compatibility with the intermediate-temperature electrolyte material Sm0.2Ce0.8O1.9 (SDC). The average thermal expansion coefficient of SCT is 21.4 × 10−6 K−1. The cathode area specific resistance (ASR) of SCT is only 0.095 Ω cm2 at 750 °C and it decreases to 0.068 Ω cm2 when SDC is added to form a SCT-SDC composite cathode. The results indicate that the SCT can be a promising alternative cathode material for IT-SOFCs.