Electrolyte engineering is critical for developing Li metal batteries. While recent works improved Li metal cyclability, a methodology for rational electrolyte design remains lacking. Herein, we propose a design strategy for electrolytes that enable anode-free Li metal batteries with single-solvent single-salt formations at standard concentrations. Rational incorporation of –CF₂– units yields fluorinated 1,4-dimethoxylbutane as the electrolyte solvent. Paired with 1 M lithium bis(fluorosulfonyl)imide, this electrolyte possesses unique Li–F binding and high anion/solvent ratio in the solvation sheath, leading to excellent compatibility with both Li metal anodes (Coulombic efficiency ~ 99.52% and fast activation within five cycles) and high-voltage cathodes (~6 V stability). Fifty-μm-thick Li|NMC batteries retain 90% capacity after 420 cycles with an average Coulombic efficiency of 99.98%. Industrial anode-free pouch cells achieve ~325 Wh kg⁻¹ single-cell energy density and 80% capacity retention after 100 cycles. Our design concept for electrolytes provides a promising path to high-energy, long-cycling Li metal batteries.

电解质工程对于开发锂金属电池至关重要。尽管最近的工作改善了锂金属的可循环性，但仍缺乏合理的电解质设计方法。本文中，我们提出了一种电解液的设计策略，该电解液可以使无阳极锂金属​​电池在标准浓度下具有单溶剂单盐形成。合理合并–CF ₂–单位产生氟化的1,4-二甲氧基丁烷作为电解质溶剂。与1 M双（氟磺酰基）酰亚胺锂配对使用时，该电解质具有独特的Li–F结合力和溶剂化鞘中的高阴离子/溶剂比，从而与两个Li金属阳极均具有出色的相容性（库仑效率〜99.52％，并在5个电极内可快速活化）周期）和高压阴极（约6 V稳定性）。厚度为50μm的Li | NMC电池在420个循环后仍保持90％的容量，平均库仑效率为99.98％。工业无阳极袋式电池在100个循环后达到约325 Wh kg ^-1的单电池能量密度和80％的容量保持率。我们的电解质设计理念为高能量，长循环锂金属电池提供了一条有希望的途径。