Entropy‐Driven Electrolytes for Sodium‐Ion Batteries: From Liquid to Solid‐State Systems

Abstract Sodium‐ion batteries (SIBs) are emerging as promising candidates for large‐scale energy storage, yet their commercialization is hindered by severe challenges related to the electrolyte, including limited ionic conductivity, poor interfacial stability, and inferior low‐temperature properties. The entropy‐driven chemistry strategy, which enhances configurational reaction and multicomponent entropy, provides an efficient thermodynamic pathway to overcome these drawbacks. This review highlights the progress of entropy‐driven strategies in SIB electrolytes, systematically connecting the solvation structure modulation at the molecular level to ion migration mechanisms and temperature‐adaptive behavior from a macroscopic view. Specifically, an in‐depth discussion on how entropy governs solvent composition and electrochemical reactions of liquid electrolytes is provided, including desolvation behavior of Na⁺, ionic conductivity, and low‐temperature activity. In addition, the ion migration behaviors resulting from the energy overlap of disordered ion transmission pathways and active sites are analyzed comprehensively. Finally, the research directions are prospected toward the commercial application of SIBs in the future, focusing on the integration of entropy‐driven chemistry with rational designs of electrode materials and electrolytes.