Tailored Sr-Co-free perovskite oxide as an air electrode for high-performance reversible solid oxide cells

Sr-Co containing perovskite oxides are prospective air electrode candidates for reversible solid oxide cells (RSOCs). However, their efficiencies limited by Sr segregation and the high thermal expansion coefficient (TEC) of Co-based perovskites. Herein, La0.6Ca0.4Fe08Ni0.2O3−δ (LCaFN) is tailored as an Sr-Co-free highperformance RSOCs. Compared with La0.6Sr0.4Fe0.8Ni0.2O3−δ (LSFN) La0.6Sr0.4Co0.2Fe0.8O3−δ (LSCoF), LCaFN has a electrical conductivity (297 S cm−1), TEC compatibility (11.2 × 10−6 K−1) improved chemical stability. Moreover, oxygen reduction reaction (ORR) activity low polarization resistance (0.06 Ω cm2) at 800°C. A single-cell Ni-YSZ/YSZ/gadolinium-doped ceria (GDC)/LCaFN-GDC operated 800°C yields maximum power density 1.08 W cm−2 using H2 fuel. In electrolysis cell (SOEC) mode, can achieve current approximately 1.2 1.3 V 70% humidity The exhibits good reversibility remains stable in continuous SOEC fuel (SOFC) modes. These findings indicate potential application material