Chloride ion batteries-excellent candidates for new energy storage batteries following lithium-ion batteries

Because of the safety issues of lithium ion batteries (LIBs) and considering the cost, they are unable to meet the growing demand for energy storage. Therefore, finding alternatives to LIBs has become a hot topic. As is well known, halogens (fluorine, chlorine, bromine, iodine) have high theoretical specific capacity, especially after breakthroughs have been made in the research of room temperature fluorine ion batteries, indicating the direction for the study of halide-ion batteries. Chlorine also has the advantages of high content, low cost, and safety, making it a potential “next-generation” electrochemical storage device. In this review, the charging and discharging principles of traditional chloride ion batteries (CIBs) are described, and the progress, principles, and existing problems of traditional CIBs, solid-state CIBs, and aqueous CIBs are elaborated from the perspectives of positive and negative electrode materials, electrolyte systems, and charging and discharging states. The application prospect and development direction of aqueous CIBs are prospected.