A novel cobalt-free layered GdBaFe2O5+δ cathode for proton conducting solid oxide fuel cells

While cobalt-containing perovskite-type cathode materials facilitate the activation of oxygen reduction, they also suffer from problems like poor chemical stability in CO2 and high thermal expansion coefficients. In this research, a cobalt-free layered GdBaFe2O5+δ (GBF) perovskite was developed as a cathode material for protonic ceramic membrane fuel cells (PCMFCs) based on proton conducting electrolyte of stable BaZr0.1Ce0.7Y0.2O3−δ (BZCY7). The button cells of Ni–BZCY7|BZCY7|GBF were fabricated and characterized using complex impedance technique from 600 to 700 °C. An open-circuit potential of 1.007 V, maximum power density of 417 mW cm−2, and a low electrode polarization resistance of 0.18 Ω cm2 were achieved at 700 °C. The results indicate that layered GBF perovskite is a good candidate for cobalt-free cathode material, while the developed Ni–BZCY7|BZCY7|GBF cell is a promising functional material system for solid oxide fuel cells.