A Highly Active Perovskite Cathode for Low‐Temperature Solid Oxide Fuel Cells: BaCo 0.7 Fe 0.22 Sc 0.08 O 3– δ

Low‐temperature solid oxide fuel cells (LT‐SOFCs) have attracted much attention for their long‐term stability, short start‐up time, and economic competitiveness. Development of a high electrochemical active cathode for the oxygen reduction reaction (ORR) is the key to LT‐SOFCs. In this study, a cubic perovskite BaCo 0.7 Fe 0.22 Sc 0.08 O 3– δ (BCFSc) is synthesized and investigated. It exhibits extremely low polarization resistances (e.g., 0.03 Ω cm 2 at 600 °C) in symmetric cell using Ce 0.8 Sm 0.2 O 1.9 (SDC) as the electrolyte, indicating an excellent ORR catalytic activity. A maximum output power density of 1446 mW cm −2 is achieved at 600 °C for a single cell with an anode functional layer, which is much larger than the one without it (1045 mW cm −2 ). The favorable performance enables BCFSc to be a candidate cathode for LT‐SOFCs.