Enhancing the Oxygen Reaction Kinetics through Compositing BaCoO3-δ with Triple Conductor BaCo0.4Fe0.4Zr0.1Y0.1O3−δ for Proton-Conducting Solid Oxide Fuel Cells

Proton conduction fuel cells (PCFCs) are emerging as a promising technology for the conversion of chemical and waste heat energy into electrical energy. However, its commercial application is often hindered by the low activity of the oxygen reduction reaction at low temperatures. In this study, a composite material consisting of BaCo0.4Fe0.4Zr0.1Y0.1O3−δ (BCFZY) and BaCoO3−δ (BCO) was synthesized to achieve a synergistic combination of proton/oxygen ion/electron triple conduction with oxygen ion/electron double conduction at a specific ratio. The utilization of the composite material led to an enhancement in conductivity and remarkable improvement in both bulk diffusion coefficient (Dchem) and the surface exchange coefficient (kchem) across all temperature ranges, effectively amplifying oxygen reaction kinetics. Furthermore, the BCFZY-BCO electrode demonstrated a remarkable enhancement in peak power density, increasing from 820 mW cm–2 to an impressive 1161 mW cm–2 at 650 °C. The integration of BCFZY and BCO presents an effective strategy for PCFCs, significantly improving overall cell performance and oxygen reaction kinetics through the synergistic effects of the composite materials.