Abstract High‐voltage lithium metal batteries (LMBs) have garnered significant attention for their high energy density, but struggle with high‐rate capability and wide‐temperature operation. Balancing high‐temperature interfacial stability with rapid low‐temperature/high‐rate desolvation kinetics remains challenging. This study introduces a polyanion‐synergized weakly solvating electrolyte strategy. Using fluoroethylene carbonate (FEC) and ethyl methyl carbonate (EMC) as weakly solvating solvents, a ternary anion system (PF 6 − /TFSI − /BOB − ) modulates the solvation structure. This results in an anion‐enhanced solvation structure enriched with contact ion pairs (CIPs) and ion aggregates (AGGs), which significantly reduces the Li⁺ desolvation energy barrier and enhances Li + transport kinetics. Moreover, the electrolyte constructs a stable electrode/electrolyte interphase (EEI) enriched with inorganic components such as LiF, Li 2 S, Li 2 SO x , Li 3 N, and Li x BO y , providing excellent mechanical and thermal stability. Additionally, LiBOB neutralizes harmful HF, further enhancing electrolyte stability. As a result, the Li||NCM811 battery demonstrates excellent cycling stability across a wide temperature range of ‐10‐60 °C at a high cutoff voltage of 4.6 V and achieves stable charge/discharge performance at a high rate of 5C. A 2.7 Ah pouch cell (359 Wh kg −1 ) also shows excellent cycling stability. This work provides novel perspectives on high‐voltage electrolyte engineering and propels LMBs toward expanded practical applications.
Li et al. (Thu,) studied this question.