Ba 0.5 Sr 0.5 Zn 0.2 Fe 0.8 O 3−δ Perovskite Oxide as a Novel Cathode for Intermediate‐Temperature Solid‐Oxide Fuel Cells

A cobalt‐free perovskite oxide, Ba 0.5 Sr 0.5 Zn 0.2 Fe 0.8 O 3−δ (BSZF), was investigated as a novel cathode material for intermediate‐temperature solid‐oxide fuel cells (IT‐SOFCs). Room‐temperature nonstoichiometry of BSZF was as high as 0.412, which was favorable for oxygen–reduction reaction. At 700°C, the polarization resistances were as low as 0.22 and 0.13 Ω·cm 2 , respectively, for pure and impregnated BSZF cathodes under open‐circuit conditions, suggesting that oxygen‐deficient BSZF was a promising cathode candidate for IT‐SOFCs.