Low concentration electrolytes for rechargeable batteries: A Review

Abstract

Low concentration electrolytes (LCEs) show various advantages, such as lower cost, better wettability, wider temperature operation, and greater variety of salt species options, which have inspired numerous research interests for a series of rechargeable batteries. Recent years have witnessed numerous successes in LCEs designs, but LCEs are still in an early development stage with insufficient scientific cognition and dissatisfactory electrochemical performances. It is therefore essential to understand more about the LCEs chemistry and gain more insight into design principles if practical applications of LCEs are expected. This review outlines the current knowledge on the LCEs designs and applications for different battery systems. The solvation/desolvation behaviors of the LCEs and the interfacial structures of the electrodes are discussed with focus on the structure-function correlations. The critical issues for the applications of LCEs are highlighted and perspectives for potential strategies to accelerate the further development of LCEs with a higher level of functionality are provided. This review will spark new endeavor to build better LCEs toward practical applications for rechargeable batteries.