Can Prussian Blue Analogues be Holy Grail for Advancing Post-Lithium Batteries?

The recent classification of lithium as a critical raw material surged the research and development (R&D) of post-lithium batteries (PLBs). The larger cation charge carriers of these PLBs consequently entailed extensive materials R&D for battery components, especially cathode. Prussian Blue (PB) and its analogues (PBAs) have emerged as promising cathode materials for PLBs due to their desirable characteristics, including a three-dimensional open framework structure that facilitates fast ion diffusion for both monovalent (Li⁺, Na⁺, K⁺) and multivalent (Mg²⁺, Ca²⁺, Zn²⁺, Al³⁺) ions, stable framework structures, electrochemical tunability, availability of widely used precursors, and ease of synthesis. Our comprehensive review reveals that several challenges are yet to be addressed in employing PBAs as cathode materials for PLBs, viz., vacancies, crystal water, side reactions, and conductivity issues. This review paper provides an exhaustive survey of material development, including the mitigation strategies of the challenges in employing PBAs as cathode materials for advancing PLBs (i. e., sodium-ion batteries (SIBs), potassium-ion batteries (KIBs), magnesium-ion batteries (MIBs), calcium-ion batteries (CIBs), zinc-ion batteries (ZIBs), aluminum-ion batteries (AIBs)) towards commercialization.