Perovskite-based nanocomposites as high- performance air electrodes for protonic ceramic cells

Hydrogen (H2) is regarded as an important energy carrier to achieve a clean and sustainable future. In particular, protonic ceramic cells (PCCs) as promising energy conversion technol-ogies have received rapidly increasing attention for the pro-duction and use of H2, showing higher energy efficiencies at reduced temperatures than oxygen-ion-conducting counter-parts. Nevertheless, the sluggish kinetics of air electrodes for oxygen reduction/evolution reactions has become one of the main obstacles to achieving high-efficiency PCCs. Therefore, the key point to realizing the commercialization of PCCs is the development of high-performance air electrodes. Particularly, perovskite-based nanocomposites received increasing interests as high-efficiency air electrodes for PCCs recently due to the synergistic effect and strong interaction between various phases with different functionalities at nanoscale. Herein, the advances of this area in 2020-2022 are mainly reviewed by highlighting the superiorities, design strategies, and remaining challenges of perovskite-based nanocomposites as air elec-trodes for PCCs at reduced temperatures.