A cleaner energy future largely depends on the development of safer, cheaper, and more sustainable battery technologies. Lithium-ion batteries (LIBs) dominate the market as the most widely used battery technology, but their high costs, safety risks, and dependence on centralized supply chains have driven demand for alternative technologies. Due to their open framework structure, which permits ion intercalation of multiple charge carriers, such as Na, K, Zn, Mg, Ca and Al, Prussian blue analogues (PBAs) have been proposed as cathode materials for next generation rechargeable batteries. Because of their tunable structure they can be used in both aqueous and non-aqueous battery systems and therefore can accommodate various battery chemistries. Nonetheless, there are still several drawbacks for PBAs that could be competed in the future developments of PBAs such as crystal defects, crystal water, low conductivity, and structural collapse due to the Jahn–Teller effect. This review article explores these challenges and discusses strategies to address and resolve them, proposing solutions for their control through synthesis methods, managing key factors during synthesis, post-synthesis modifications, crystal enhancement via doping, and surface modification. Furthermore, some of the strengths and weaknesses encountered when employing these materials in other M-ion batteries (M = Na, K, Mg, Zn, Ca, Al) are also presented. Linking fundamental material science to applied research, and focusing on the possible role for PBAs as sources of energy storage in a safe, cheap and environmentally- friendly manner particularly at the grid-scale and stationary levels. Finally, it identifies significant areas of need for research that would improve its commercial maturity and indicates the world energy storage technology that could be potentially affected by PBAs.
