Ca- and Ni-Doped Pr0.5Ba0.5FeO3−δ as a Highly Active and Robust Cathode for High-Temperature Solid Oxide Fuel Cell

In general, La1–xSrxMnO3 (LSM) has been commonly used as a cathode for the commercial high-temperature solid oxide fuel cell (SOFC), but it is better to develop a cathode with higher and longer performance at high temperature (>900 °C). In this regard, Fe-based mixed ionic electronic conductors can be considered as one of the potential candidates for the replacement of LSM in terms of excellent catalytic activity. However, they suffer from performance degradation due to the coarsening of particles during high-temperature fabrication and operation. Herein, Ca- and Ni-doped Pr0.5Ba0.5FeO3−δ (PBF) is studied, where Ca doping on Ba improves the electronic/ionic conductivity and Ni doping on Fe further enhances the thermal stability. The optimal composition of Pr0.5Ba0.3Ca0.2Fe0.7Ni0.3O3−δ (PBCFNi30) cathode shows a very low cathodic polarization resistance of 0.061 Ω cm2 with a small degradation rate of 0.086 × 10–3 Ω cm2/h at 850 °C. Therefore, PBCFNi30 can be considered as a promising cathode for commercial high-temperature SOFC.