Mechanistic Understanding of Oxygen Electrodes in Rechargeable Multivalent Metal-Oxygen Batteries

Abstract

Rechargeable multivalent metal-O2 batteries (Mg−O2, Zn−O2 and Al−O2 etc.) are promising next-generation battery technologies for electric automobiles and large-scale energy storage owing to their high energy density, low cost, and sustainability. To realize the full potentials of these systems, an in-depth mechanistic understanding of the underlying chemistries is crucial for rational development. However, compared with the intensively studied Li−O2 batteries, reaction mechanisms of multivalent metal-O2 batteries are much less understood. Here, we discuss the current status of mechanistic understanding of oxygen reduction and evolution reactions in rechargeable multivalent metal-O2 batteries. We discuss the key open questions and future research directions of multivalent metal-O2 batteries using examples and experiences from Li−O2 batteries, which could guide and inspire the development of multivalent metal-O2 batteries.