The Distance Between Phosphate‐Based Polyanionic Compounds and Their Practical Application For Sodium‐Ion Batteries

Abstract Sodium‐ion batteries (SIBs) are a viable alternative to meet the requirements of future large‐scale energy storage systems due to the uniform distribution and abundant sodium resources. Among the various cathode materials for SIBs, phosphate‐based polyanionic compounds exhibit excellent sodium‐storage properties, such as high operation voltage, remarkable structural stability, and superior safety. However, their undesirable electronic conductivities and specific capacities limit their application in large‐scale energy storage systems. Herein, the development history and recent progress of phosphate‐based polyanionic cathodes are first overviewed. Subsequently, the effective modification strategies of phosphate‐based polyanionic cathodes are summarized toward high‐performance SIBs, including surface coating, morphological control, ion doping, and electrolyte optimization. Besides, the electrochemical performance, cost, and industrialization analysis of phosphate‐based polyanionic cathodes for SIBs are discussed for accelerating commercialization development. Finally, the future directions of phosphate‐based polyanionic cathodes are comprehensively concluded. It is believed that this review can provide instructive insight into developing practical phosphate‐based polyanionic cathodes for SIBs.