Constructing better electrode–electrolyte interphases in sodium‐ion battery cathodes

Abstract Sodium‐ion batteries (SIBs) represent a promising alternative to lithium‐ion systems for energy storage, owing to sodium's natural abundance and low cost. However, their widespread adoption is hindered by issues with electrode–electrolyte interphases (EEIs). The larger ionic radius of Na + creates original challenges of interfacial incompatibility during its insertion and extraction, posing critical issues for electrochemical performance in SIBs. Therefore, a systematic summary of recent research is necessary to illuminate the rational design strategies for stable EEIs. Here, the configuration characteristics of cathode materials for SIBs, accompanied by the associated issues, have been studied. The key factors that determine EEIs have been identified within a framework that reveals the specific mechanisms and outcomes between the crystal structure and surface chemistry of cathodes. Recent works on EEIs are classified and summarized into three categories: electrolyte engineering, auxiliary component engineering, and electrode engineering. Based on the critical assessment, several significant perspectives on future research directions and challenges are proposed. This review aims to offer valuable insights into developing better EEIs, acknowledging their pivotal role in practical SIBs cathode technology. image