A Comprehensive Review of Cathode Materials for Advanced Aqueous Zinc-Ion Batteries

As lithium-ion batteries (LIBs), which have recently been applied as large-scale energy storage systems, reveal safety, economic, and environmental concerns, the need for the development of rechargeable batteries is increasing. In this context, aqueous zinc-ion batteries (AZIBs), which use an aqueous electrolyte instead of an organic electrolyte to increase stability and high efficiency, can be an alternative to overcome the disadvantages of LIBs. In addition, the advantages of economic feasibility, excellent properties of Zn metal, high safety, and easy manufacturing process are drawing more attention to the development of AZIBs. Therefore, in this review, we account for the energy storage mechanism of AZIBs, such as insertion/extraction of Zn²⁺ ion, coinsertion/extraction with H⁺ and Zn²⁺ ions, and chemical conversion, and we explain various kinds of cathode materials that are used in AZIBs. Furthermore, several strategies that can increase the electrochemical performance of AZIB cathode materials and the future research challenges of AZIBs are suggested.