Proton conducting oxides: A review of materials and applications for renewable energy conversion and storage

Recent developments in proton conducting oxides (PCOs) present a promise of economic and sustainable energy conversion and storage devices such as protonic ceramic fuel cells, protonic ceramic electrolysis cells, gas purification, syn-gas membrane, and ammonia synthesis. This review provides a comprehensive overview of the development and recent trends in electrochemical cells based on the PCOs. Various protonic electrochemical cells are described here with basic working principles and critical parameters affecting the performance. Also, the electrochemical properties and recent progress on the PCO materials are reviewed and discussed. The overview of PCOs provides guidelines for the scientific-based rational design of PCO materials for the efficient protonic energy conversion and storage applications in academic and industrial fields.