Three‐Dimensional Electrodes for Oxygen Electrocatalysis

Abstract Rechargeable metal‐air batteries have drawn extensive attention because of their remarkably high theoretical energy output and the ultra‐stable voltage platform but are restricted by the sluggish kinetics of oxygen reduction/evolution reactions at the cathode. To resolve this issue, great efforts have been made in focusing the three‐dimensional (3D) electrodes, which can provide adequate hierarchical channels and ensure the gas penetration of the air electrodes. Therefore, it is necessary to give a timely updates of 3D electrodes. In this review, we present the fundamentals and recent progress of 3D electrodes in oxygen reduction/evolution reactions, mainly including the 3D electrode design, the electrocatalysis in oxygen reduction, oxygen evolution and the bi‐functional activity of the two reactions. Besides, metal‐air batteries facilitated with 3D electrodes are also fully discussed, including the mechanisms based on the aqueous and organic electrolytes. At the end, the existing challenges and perspectives of 3D electrodes are proposed for further development of the metal‐air batteries and auxiliary generative ideas for the renewable energy development.