Stable interfaces constructed by concentrated ether electrolytes to render robust lithium metal batteries

Lithium metal batteries (LMBs) are highly considered as promising candidates for next-generation energy storage systems. However, routine electrolytes cannot tolerate the high potential at cathodes and low potential at anodes simultaneously, leading to severe interfacial reactions. Herein, a highly concentrated electrolyte (HCE) region trapped in porous carbon coating layer is adopted to form a stable and highly conductive solid electrolyte interphase (SEI) on Li metal surface. The protected Li metal anode can potentially match the high-voltage cathode in ester electrolytes. Synergistically, this ingenious design promises high-voltage-resistant interfaces at cathodes and stable SEI with abundance of inorganic components at anodes simultaneously in high-voltage LMBs. The feasibility of this interface-regulation strategy is demonstrated in Li | LiFePO₄ batteries, realizing a lifespan twice as long as the routine cells, with a huge capacity retention enhancement from 46.4% to 88.7% after 100 cycles. This contribution proof-of-concepts the emerging principles on the formation and regulation of stable electrode/electrolyte interfaces in the cathode and anode simultaneously towards the next-generation high-energy–density batteries.