Enhanced performance in SOFC cathodes via B‐site co‐dopant switching in PBSCF0.25 and PBSFC0.25 layered perovskites

Abstract Two cathodes, PrBa 0.5 Sr 0.5 Fe 1.75 Co 0.25 O 5+ δ (PBSFC0.25) and PrBa 0.5 Sr 0.5 Co 1.75 Fe 0.25 O 5+ δ (PBSCF0.25), were synthesized by a wet chemistry route through complexing agent's process. Thermogravimetric analysis and differential thermal analysis were done for the uncalcined powders to observe the thermal behavior. Pure single‐phase structures of the compounds were obtained after a final sintering temperature of 1100°C for 5 h. Samples were crystallized in the orthorhombic structure in the space group (Pmmm). Scanning electron microscope and EDS analysis show the crystalline composites with excellent porosity percentages. The porosity was higher in PBSFC2.5 than PBSCF0.25. Conductivities of two cathodes were examined in air environment from 500 to 800°C with an interval of 50°C. It has found that PBSFC0.25 is higher in conductivity of 3.0068 S/cm with less polarization resistance of 0.05 Ω than PBSCF0.25 with conductivity of 2.306 S/cm and polarization resistance of 0.066 Ω. PBSFC0.25 has shown a reasonable enhancement in performance of 0.699 W/cm 2 at 800°C, higher than PBSCF0.25 (0.608 W/cm 2 ) at the same temperature. Even at 600°C, the power density of PBSFC0.25 was 0.245 W/cm 2 , higher than the PBSFC0.25, which was found to be 0.220 W/cm 2 . Thereby, PBSFC2.5 is recommended to be a good candidate for air electrode at the intermediate range temperature.