Recent progress in oxygen electrodes for protonic ceramic electrochemical cells

Protonic ceramic electrochemical cells, a promising technology for energy conversion and storage, have garnered significant interest in recent years owing to their superior low-temperature (< 600 °C) performance relative to solid oxide electrochemical cells. However, the sluggish kinetics of oxygen electrodes have impeded further advancements. Despite considerable research efforts, the development of practically applicable oxygen electrodes remains challenging. We herein review the recent research focusing on the fundamental understanding and development of oxygen electrode materials. Furthermore, we provide a range of material design strategies for enhancing the catalytic activity of oxygen electrodes along with a concise overview of potential derivative applications. Finally, the perspectives and potential directions for the development of oxygen electrodes for high-performance protonic ceramic electrochemical cells are presented.