A cobalt-free Sm0.5Sr0.5FeO3−δ–BaZr0.1Ce0.7Y0.2O3−δ composite cathode for proton-conducting solid oxide fuel cells

Abstract A cobalt-free Sm 0.5 Sr 0.5 FeO 3− δ –BaZr 0.1 Ce 0.7 Y 0.2 O 3− δ (SSF–BZCY) was developed as a composite cathode material for proton-conducting solid oxide fuel cells (H-SOFC) based on proton-conducting electrolyte of stable BZCY. The button cells of Ni-BZCY/BZCY/SSF–BZCY were fabricated and tested from 550 to 700 °C with humidified H 2 (～3% H 2 O) as a fuel and ambient oxygen as oxidant. An open-circuit potential of 1.024 V, maximum power density of 341 mW cm −2 , and a low electrode polarization resistance of 0.1 Ω cm 2 were achieved at 700 °C. The experimental results indicated that the SSF–BZCY composite cathode is a good candidate for cathode material.