Recent Advances in Perovskite Air Electrode Materials for Protonic Solid Oxide Electrochemical Cells

Abstract

Intermediate-temperature proton-conducting solid oxide cells (P-SOCs) have emerged as a promising technology for power generation and hydrogen production. They have gained significant attention due to their lower operating temperature, higher efficiency, better safety and durability and simplified water management over conventional high-temperature oxygen-conducting solid oxide cells (O-SOCs). However, the performance of P-SOC air electrodes is hindered by the sluggish kinetics of oxygen reduction and evolution reactions, necessitating efficient conductivities of H+, O2−, and e−. Despite critical advancements, the search for optimal air electrode materials remains challenging. This review provides a comprehensive overview of recent advancements in perovskite materials for P-SOC air electrodes, covering from fundamental mechanisms, material development, theoretical modeling, and practical applications. It highlights key progress in reaction kinetics, structure–property relationships, and modification strategies across widely studied perovskite-based systems. Particular emphasis is placed on understanding the correlation between structural characteristics and the electrochemical activity and stability of electrodes, which is essential for the rational design of high-performance, durable P-SOC materials. Additionally, advanced methodologies and mechanistic insights into newly developed air electrode materials are explored, with a focus on the role of theoretical simulations, including artificial intelligence (AI)-driven machine learning (ML) techniques. Finally, perspectives are provided on the future development of high-performance P-SOC air electrodes for industrial applications.