Self-Assembled Triple-Conducting Nanocomposite as a Superior Protonic Ceramic Fuel Cell Cathode

Protonic ceramic fuel cells (PCFCs) have attracted more attention than solid oxide fuel cells based on oxygen-ion-conducting electrolytes that operate at intermediate temperatures due to the lower activation energy for proton conduction than for oxygen ions in oxide electrolytes. However, the practical application of PCFC technology is hindered by the lack of suitable cathode materials. Here, we report our rationally designed triple conducting nanocomposite cathode BaCo_0.7(Ce_0.8Y_0.2)_0.3O₃-_δ with sufficient oxygen ion-proton-electron transfer capability for PCFCs. This work develops the highly active and stable cathode material and simultaneously measures the specific values of oxygen ion, proton, and electron conductivity of the cathode material. This work also highlights the design strategy of perovskite-based electrocatalysts for other energy conversion and storage systems such as water splitting, metal-air batteries, and dye-sensitized solar cells.