Self-Compartmented Electrolyte Design for Stable Cycling of Lithium Metal Batteries under Extreme Conditions

Electrolyte is the key component dictating lithium battery performance, especially under extreme conditions such as fast cycling and low temperatures. However, conventional electrolyte design principles, which generally rely on a homogeneous mixture of solvents, salts, and functional additives, fail to simultaneously meet the requirements for both anodic/cathodic interfacial stability and bulk ion-transport kinetics in lithium metal batteries. Herein, we present a self-compartmented electrolyte design methodology. Lithium 4,5-dicyano-2-(trifluoromethyl)imidazol-1-ide (LiTDI), featuring the ability to selectively self-assemble on the cathode/electrolyte interface, compartmented the electrolyte into a heterogonous one. Close to the cathode side, LiTDI could induce an interfacial high-concentration region, where the anion-rich solvation structure facilitates the formation of a stable cathode-electrolyte interphase (CEI). In the bulk, the electrolyte maintains a low concentration with low viscosity, ensuring fast ion transport and superior rate performance. Li||NCM811 cells achieve over 500 stable cycles with 80.3% capacity retention and deliver 169.3 mAh g^-1 at a 10C discharge rate. Under low-temperature conditions (-20 °C), the cells maintained outstanding stability over 700 cycles at 0.5C charge/discharge, achieving capacity retention of 96.6% and an average Coulombic efficiency of 99.2%. This work provides a new electrolyte design paradigm, addressing the critical challenges of LMBs for high-voltage and low-temperature applications.