Elucidating the Solvating Power of Solvents for Designing High-Performance Electrolytes in Lithium Batteries

The advancement of electrolytes is crucial for driving the progress of lithium (Li) batteries. Electrolyte performance is largely determined by its solvation structure, which is influenced by the solvating power of the solvents. Thus, a quantitative descriptor for the solvating power of solvents is highly required to rationally design high-performance electrolytes. However, a unified quantitative descriptor for the solvating power of solvents has not been established. This review summarizes the developed quantitative descriptors of solvating power, categorizing them into three types based on the intrinsic properties of solvents, the interaction strength between probes and solvents, and the bulk properties of electrolytes. The physicochemical significance and explorations in guiding the electrolyte design of these quantitative descriptors are discussed in detail. Moreover, strategies for regulating the solvating power of the solvents are presented. Finally, an outlook on investigating the solvating power of solvents and guiding the rational design of high-performance electrolytes is proposed.