Abstract

Abstract Aqueous sodium‐ion batteries (ASIBs) are a compelling option for energy storage systems due to their high ionic conductivity, excellent cycle stability, high safety, low cost, and environmental friendliness. However, ASIBs present challenges because of low energy density and lack of suitable cathode materials, which limit their practical deployment. Prussian blue analogues (PBAs) are metal‐organic coordination materials that have open frameworks, making sodium ions easier to insert and extract. Their excellent stability and high specific capacity in aqueous electrolytes make them an attractive choice for ASIBs cathode materials. In this review, the research progress on PBAs as cathodes for ASIBs is discussed. Their crystal structure and sodium storage mechanism are elucidated, and strategies to improve the performance of PBAs are summarized in depth at the material level. New insights are put forward aiming to provide ideas for improving cycling performance, avoiding electrode dissolution, and improving energy density of PBAs for ASIBs. In addition, the performance and current issues of full cells are summarized and discussed to evaluate the commercialization potential of ASIBs, providing an outlook on research directions in the development of high‐performance aqueous batteries in grid‐scale applications.