Localized high-concentration electrolyte enabled by a novel ester diluent for lithium metal batteries.

To achieve stable Li anode cycling with a high-voltage cathode and high efficiency, a novel ester diluent-based localized high-concentration electrolyte (LHCE) was successfully applied. The oxidation resistance of the high-concentration electrolyte is retained after dilution. More than 99.5% Coulombic efficiency is achieved in Li||Cu cells owing to the optimized physical properties, and the robust SEI film enables superior long-term operation with a high-voltage cathode. This strategy verifies the effectiveness of developing ester diluents for LHCEs applied in lithium metal batteries.