Entropy‐Driven Design of Stable High‐Performance Sodium‐Ion Battery Cathodes

ABSTRACT Sodium‐ion batteries (SIBs) are emerging as a viable and cost‐effective alternative to lithium‐ion batteries, benefiting from sodium's high terrestrial abundance. However, their practical application is limited by rapid capacity fading stemming from structural instability during cycling and intrinsically sluggish Na + diffusion kinetics. High‐entropy materials (HEMs), through configurational entropy maximization and multi‐cation synergy, provide a promising strategy to stabilize structures and enhance the energy of SIB cathodes. This review focuses on the structural and chemical principles of key SIB cathodes—layered oxides and Prussian blue analogs—and critically evaluates high‐entropy engineering strategies to performance enhancement. Mechanistic insights into entropy‐driven performance enhancement are analyzed alongside current challenges and future research directions. The high‐entropy strategy offers significant flexibility in cathode design, potentially overcoming conventional material limitations and accelerating commercialization. Although in its nascent stages, requiring extensive fundamental investigation, this analysis aims to guide the development of next‐generation entropy‐stabilized cathodes and advance SIB technologies.