The progress of cathode materials in aqueous zinc-ion batteries

Rechargeable aqueous zinc-ion batteries (AZIBs), a promising energy storage device in the large-scale energy storage market, have attracted extensive attention in recent years due to their high safety, low cost, environmental friendliness, and excellent electrochemical performance. Despite the rapid development of AZIBs technology, challenges such as insufficient energy density and limited cycling life still exist, which hinders the practical application of AZIBs. Due to the critical role that cathode materials play in the electrochemical performance of AZIBs, it is necessary to summarize the progress of cathode materials for AZIBs. In this review, the Zn2+ storage mechanisms of the cathode materials are analyzed. Subsequently, the representative cathode materials are introduced, and their structures and electrochemical performances are compared. The existing problems and improvement strategies of these cathode materials are summarized in detail. Finally, the future challenges and promising prospects for cathode materials are proposed. This review will guide researchers and manufacturers, benefiting them in designing advanced AZIBs for grid-scale energy storage.