A molecular review on weakly solvating electrolytes for lithium batteries

Abstract

Carbonate-based electrolytes have significantly advanced the practical applications of lithium batteries (LBs) in various fields. However, commercial carbonate-based electrolytes exhibit sluggish desolvation behavior, resulting in poor performance of LBs under fast-charging and low-temperature conditions. In contrast, weakly solvating electrolytes (WSEs) have demonstrated rapid desolvation due to relatively weak Li⁺–solvent interactions. This review summarizes the recent progress of molecular design strategies for WSEs. First, the origins and characteristics of WSEs are analyzed. The dielectric constant (ε) and donor number (DN) of solvents affect the interactions among Li⁺, solvents, and anions, which are critical for the formation of WSEs. Both theoretical calculations and experimental characterizations are introduced to afford qualitative or quantitative WSE investigation. The solvent molecule design strategies for WSEs are summarized, including increasing steric hindrance, reducing the number of donor atoms, and reducing the negative charge on donor atoms. Finally, insightful perspectives are proposed to advance the development of WSEs in practical LBs.