Ag-doped BaCo0.4Fe0.4Zr0.1Y0.1O3-δ as a promising cathode material for proton-conducting solid oxide fuel cells

Proton-conducting solid oxide fuel cells (H-SOFCs) demonstrate substantial potential for intermediate-to-low temperature operation due to the lower migration activation energy of protons (H + ) compared to oxygen ions (O 2− ). To address the critical role of cathode materials in determining cell performance, this study employs an A-site silver (Ag) doping strategy in perovskite oxide. BaCo 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BCFZY), Ba 0.95 Ag 0.05 Co 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BACFZY) and Ba 0.9 Ag 0.1 Co 0.4 Fe 0.4 Zr 0.1 Y 0.1 O 3-δ (BACFZY-1) materials are all prepared using the sol-gel synthesis method. The investigation into the structure and element distribution of the synthesized materials reveals that BACFZY remains in a pure perovskite phase, with all elements evenly dispersed throughout. Ag-doped BACFZY surpasses BCFZY with greater electrical conductivity and thermal expansion compatibility. Moreover, the incorporation of Ag in BACFZY cathode facilitate the oxygen adsorption, leading to lower impedance and superior output performance with maximum peak power density of 1160 mW cm −2 at 650 °C. Meanwhile, The BACFZY cell maintained stable operation for 100 h. The aforementioned experimental findings indicate that the BACFZY material is a promising cathode for H-SOFC.