Dipole–dipole interactions for inhibiting solvent co-intercalation into a graphite anode to extend the horizon of electrolyte design

Abstract

Developing advanced electrolytes is indispensable for next-generation lithium-ion batteries (LIBs). Yet the strong solvating interaction between Li⁺ and various solvents often leads to sluggish desolvation and solvent co-intercalation into graphite electrodes, thus limiting the scope of electrolyte design. Here, we present a mechanism of dipole–dipole interactions to facilitate desolvation and inhibit co-intercalation through deliberately tuning the interactions among Li⁺, solvents and non-coordinating molecules (non-solvents). Specifically, the non-solvents counteract electrostatic attractions to tame the affinity between Li⁺ and solvents without altering the primary solvation structure at medium Li salt concentration. Consequently, the weakened Li⁺-solvent strength enables facile desolvation and thus superior electrochemical compatibility with graphite anodes for various solvents including DME (1,2-dimethoxyethane), DMSO (dimethyl sulfoxide), TMP (trimethyl phosphate), PC (propylene carbonate) and DEC (diethyl carbonate). We believe that the strategy of dipole–dipole interactions can extend the horizon of electrolyte design towards achieving advanced LIBs.