High-entropy liquid electrolytes in rechargeable batteries: Merits and challenges

The growing severity of environmental challenges has accelerated advancements in renewable energy technologies, highlighting the critical need for efficient energy storage solutions. Rechargeable batteries, as primary short-term energy storage devices, have seen significant progress. Among emerging optimization strategies, high-entropy electrolytes have garnered attention for their superior ionic conductivity and ability to broaden batteries’ operational temperature ranges. Rooted in the thermodynamic concept of entropy, high-entropy materials, originally exemplified by high-entropy alloys, have demonstrated enhanced structural stability and advanced electrochemical performance through the synergistic integration of multiple components. High-entropy liquid electrolytes, both aqueous and non-aqueous, offer unique opportunities for entropy manipulation due to their inherently disordered structures. However, their complex compositions present challenges, as minor changes in formulation can lead to significant performance variations. This review introduces the fundamentals of entropy tuning, surveys recent advances in high-entropy liquid electrolytes, and analyzes the interplay between entropy and electrochemical behavior. Finally, it discusses design strategies and future perspectives for the practical implementation of high-entropy liquid electrolytes in next-generation energy storage systems.