Atomically dispersed multi-site catalysts: bifunctional oxygen electrocatalysts boost flexible zinc-air battery performance

The development of efficient bifunctional catalysts for the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) during charge-discharge cycling is crucial to the advancement of flexible zinc-air batteries (FZABs). Atomically dispersed multi-site catalysts have garnered extensive attention in the development of FZABs owing to their well-defined structures, high atomic utilization, and remarkable activity. However, the flexibility of the battery facilitates bending and deformation, exacerbating the agglomeration of atomically dispersed multi-site catalysts. Simultaneously, the loading method of the catalyst at the cathode presents a hindrance to the commercialization of FZABs. Herein, we present a comprehensive overview of atomically dispersed multi-site catalysts exhibiting diverse dispersion site structures and exceptional activity for bifunctional oxygen electrocatalysis and emphasize their potential for industrial applications. Manipulation strategies are summarized to enhance the bifunctional activity of atomically dispersed multi-site catalysts, including the utilization of highly electronegative ligands, design principles for polymetallic centers, and exploration of atomic clusters. Ultimately, the comprehensive summary presents the potential applications and associated challenges of atomically dispersed multi-site catalysts in the cathode region of rechargeable FZABs, with the aim of providing valuable insights for future commercialization. Based on the advancements in atomically dispersed multi-site catalysts for FZABs, this review discusses the design methodologies to regulate the performance of bifunctional oxygen electrocatalysts from the electronic and geometric structures.