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 technologies have received rapidly increasing attention for the production and use of H₂, showing higher energy efficiencies at reduced temperatures than oxygen-ion-conducting counterparts. 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 electrodes for PCCs at reduced temperatures.