Recent progress on cathode materials for protonic ceramic fuel cells

Protonic ceramic fuel cells (PCFCs) have recently garnered significant interest due to their high efficiency and low emissions operating in the intermediate temperature range (400−700 °C). However, due to the lack of efficient key cell materials, especially cathode materials with triple-conducting (O²⁻/H⁺/e⁻) characteristics, the practical application of PCFCs lags behind other energy conversion technologies. Over the past decade, considerable efforts have been devoted to the development of efficient triple-conducting cathode materials, leading to a remarkable progress in PCFCs performance. This review provides a comprehensive summary of the development of cathode materials in PCFCs, including the reaction mechanism, essential cathode material features, regulation strategies, and recent advancements. Challenges and research perspectives in this field are also presented. The focus is on harnessing the fundamental principles of compositional engineering and advanced technologies to provide valuable guidance for the design and development of novel cathode materials for high-performance PCFCs and related fields.