Li-based batteries are ubiquitous in modern-day energy supply systems. However, the volatile and flammable nature of the electrolytes remains a safety challenge. Here, we report that anchored solvent molecules can increase the ionic conductivity of the electrolyte without undermining its non-flammability. Specifically, we developed a liquid-state polymer electrolyte composed of LiFSI salts, dimethoxyethane (DME) solvents, and polysiloxane tethered with ion-solvating moieties. DME coordinates with both the salt and the polymer, while, together with the salt, they synergistically plasticize the polymer to increase the ionic conductivity. The resulting non-flammable polymer electrolyte has a room-temperature ionic conductivity of 1.6 mS/cm and a wide operation window of 25°C–100°C. Benefiting from its liquid nature, our electrolyte can pair with commercially available electrodes without further cell engineering. Our work extends the ionic conductivity range of polymer electrolytes and shows a promising design pathway for next-generation safe and manufacturable electrolytes.

锂电池在现代能源供应系统中无处不在。然而，电解质的挥发性和易燃性仍然是一个安全挑战。在这里，我们报告锚定的溶剂分子可以增加电解质的离子电导率而不破坏其不可燃性。具体而言，我们开发了一种由 LiFSI 盐、二甲氧基乙烷 (DME) 溶剂和聚硅氧烷与离子溶剂化部分连接而成的液态聚合物电解质。DME 与盐和聚合物配位，同时与盐一起协同增塑聚合物以提高离子电导率。所得不可燃聚合物电解质的室温离子电导率为 1.6 mS/cm，工作范围为 25°C–100°C。得益于其液体性质，我们的电解质无需进一步的电池工程即可与市售电极配对。我们的工作扩展了聚合物电解质的离子电导率范围，并为下一代安全且可制造的电解质展示了一条有前途的设计途径。