High-performance fluorine-doped cobalt-free oxide as a potential cathode material for solid oxide fuel cells

Abstract The potential utilization of the cobalt-free fluorine-doped LaBa0.5Sr0.5Fe2O5.875-δF0.125 oxide as a solid oxide fuel cell (SOFC) cathode candidate is investigated and assessed. The polarization resistance of the LaBa0.5Sr0.5Fe2O5.875-δF0.125 cathode is 0.089 Ω cm2 at 750 °C, and meanwhile, a larger power density of the electrolyte-supported single cell with the LaBa0.5Sr0.5Fe2O5.875-δF0.125 cathode is 511 mWcm−2. In addition, the electrode still possesses a better stability after 120 h operation. Combining with the oxygen reduction kinetics research and the corresponding distribution of relaxation time analysis, rate-determining steps are further defined. Current research results indicate that the LaBa0.5Sr0.5Fe2O5.875-δF0.125 sample is an attractive cathode for SOFCs.