Sulfolane?Graphite Incompatibility and Its Mitigation in Li?ion Batteries

The non-flammability and high oxidation stability of sulfolane (SL) make it an excellent electrolyte candidate for lithium-ion batteries (LIBs). However, its incompatibility with graphitic anode prevents the realization these advantages. To understand how this arises on molecular level so that can be suppressed, we combined theoretical calculation experimental characterization reveal primary Li+ solvation sheath in SL is depleted fluorine source. Upon reduction, such fluorine-poor generates insoluble dimer poor electronic insulation, hence leading to slow but sustained parasitic reactions. When content Li+-SL increased via salt concentration, a LiF-rich interphase graphite formed. This new understanding failure mechanism SL-based great significance unlocking many possible solvent candidates high-voltage cathode materials next-generation LIBs.