In Situ Self‐Assembly of Core–Shell Multimetal Prussian Blue Analogues for High‐Performance Sodium‐Ion Batteries

Abstract Metal–organic frameworks (MOFs), such as Prussian blue and its analogues (PB and PBAs) with open frameworks have attracted tremendous attentions as cathode materials for sodium‐ion batteries, owing to their simple method of synthesis and high theoretical specific capacity. In this study, core–shell‐structured PBAs are prepared by an in situ self‐assembly method. Owing to the advantages of both constituents, the as‐prepared core–shell PBAs show excellent rate and cycling electrochemical properties through a dual‐level‐controlled charge–discharge depth mechanism. It delivers a specific capacity of 104.3 mAh g −1 at 0.1 C, as well as a remarkably enhanced cycle performance, giving 88.3 % of its initial capacity over 1000 cycles at 300 mA g −1 . In particular, the coating strategy described herein could be extended to other MOF materials, leading to wider application in energy storage.