Understanding the Applications of Material Analytical Techniques in Prussian Blue Analogues for Sodium Ion Batteries

Prussian blue analogues (PBAs) have been regarded as one of commercially viable cathode materials in Na-ion batteries (NIBs) in recent years. However, PBAs commercialization process is still difficult and slow. To promote the development of PBAs, the application progress of material analytical techniques in chemical composition, valence state, and structure for low-cost Fe- and Mn-based PBAs is purposefully summarized considering commercial relevance. Particularly, structural analysis techniques for Fe and Mn-based PBAs have been extended to cover their crystal, electronic, morphological, molecular and electrochemical interface properties. These analytical techniques are powerful tools for elucidating the intrinsic material characteristics of Fe and Mn-based PBAs. More importantly, the elaborations of structure-property relationship and sodium-ion storage mechanism for Fe and Mn-based PBAs are opportunistically integrated into above-mentioned technique analysis. This review is hoped to serve as a manual and help people to rapidly and clearly conduct PBAs researches for accelerating NIBs commercialization.