Recent progress of Prussian blue analogues as cathode materials for metal ion secondary batteries

With the rapid development of new energy and the high proportion of new energy connected to the grid, energy storage has become the leading technology driving significant adjustments in the global energy landscape. Electrochemical energy storage, as the most popular and promising energy storage method, has received extensive attention. Currently, the most widely used energy storage method is metal-ion secondary batteries, whose performance mainly depends on the cathode material. Prussian blue analogues (PBAs) have a unique open framework structures that allow quick and reversible insertion/extraction of metal ions such as Na+, K+, Zn-2+,Zn- Li+ etc., thus attracting widespread attention. The advantages of simple synthesis process, abundant resources, and low cost also distinguish it from its counterparts. Unfortunately, the crystal water and structural defects in the PBAs lattice that is generated during the synthesis process, as well as the low Na content, significantly affect their electrochemical performance. This paper focuses on PBAs' synthesis methods, crystal structure, modification strategies, and their potential applications as cathode materials for various metal ion secondary batteries and looks forward to their future development direction.