Tuning Pr0.5Ba0·5FeO3-δ cathode to enhanced stability and activity via Ca-doping for symmetrical solid oxide fuel cells

The advancement of symmetrical solid oxide fuel cells (SSOFCs) is hindered by the significant challenge of finding electrode materials that exhibit both high activity and superior stability. In this work, Ca-doped Pr0.5Ba0·5FeO3-δ (Pr0.5Ba0·1Ca0·4FeO3-δ, Ca–PBF) is investigated as an electrode material for SSOFCs. The catalytic activity for oxygen reduction and fuel oxidation is greatly enhanced by the introduction of Ca into the Ba-site, leading to improved efficiency in oxygen diffusion. At 700 °C in air, the cathode polarization resistance decreases from 0.95 to 0.53 Ω cm2 and the anode polarization resistance decreases from 2.42 to 1.23 Ω cm2 when exposed to wet H2. With enhanced catalytic activity, the symmetrical cell with Ca–PBF exhibits a peak power density of 480 mW cm−2 at 700 °C in wet H2. More importantly, the symmetrical cell with Ca–PBF demonstrates stable performance for 100 h in wet H2. The results demonstrate that Ca–PBF has great potential as an electrode material for SSOFC and can be one of the candidates for practical applications.