Single-atom catalyst cathodes for lithium-oxygen batteries: a review

Recently, single-atom catalysts (SACs) have been found to be promising candidates for oxygen electrocatalysis in rechargeable lithium-oxygen batteries (LOBs) owing to their high oxygen electrocatalytic activity and high stability, which originates from their unique coordination environments and electronic properties. As a new type of catalyst for LOBs, the advancements have never been reviewed and discussed comprehensively. Herein, breakthroughs in the design of various types of SACs as cathode catalysts for LOBs are summarized, including Co-based, Ru-based, and other types of SACs. Moreover, considerable emphasis is placed on the correlations between the structural feature of the SAC active sites and the electrocatalytic performance of LOBs. Finally, an overview and challenges of SACs for practical LOBs are also provided. This review provides an intensive understanding of SACs for designing efficient oxygen electrocatalysis and offers useful guidelines for the development of SACs in the field of LOBs.