A cobalt-free Sm _0.5Sr _0.5FeO _3-δ- BaZr _0.1Ce _0.7Y _0.2O _3-δ composite cathode for proton-conducting solid oxide fuel cells

A cobalt-free Sm _0.5Sr _0.5FeO _3-δ- BaZr _0.1Ce _0.7Y _0.2O _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 ₂O) 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.