High-performance perovskite Ba 0.5 Sr 0.5 Co 0.8 Fe 0 .1 Zn 0.1 O 3 − δ –La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3 − δ composite cathode

A new composite oxide, Ba0.5Sr0.5Co0.8Fe0.1Zn0.1O3−δ–La0.6Sr0.4Co0.2Fe0.8O3−δ, was investigated as a cathode material for intermediate-temperature solid-oxide fuel cells. The area-specific polarization resistance of the Ba0.5Sr0.5Co0.8Fe0.1Zn0.1O3−δ–La0.6Sr0.4Co0.2Fe0.8O3−δ composite cathode was extracted from the impedance spectrum of a symmetric cell employing two composite cathodes. Its value of 0.078Ωcm2 at 600°C is ~64% lower than that of a Ba0.5Sr0.5Co0.8Fe0.1Zn0.1O3−δ cathode (0.215Ωcm2) and one order of magnitude lower than that of a La0.6Sr0.4Co0.2Fe0.8O3−δ cathode (1.06Ωcm2). Furthermore, it was determined that this composite cathode could maintain its long-term stability without microstructural change.