In situ-polymerized electrolytes via molecular engineering: Synergistic anion trapping and interfacial stabilization...

Conventional polymer electrolytes face significant challenges due to their inherent low ionic conductivity and poor interfacial stability. In this work, we develop an innovative in-situ polymerized multifunctional electrolyte system that simultaneously addresses solvation structure regulation and interfacial ion transport optimization. The designed electrolyte demonstrates three key advancements. On one side, lithium difluoro(oxalato)borate (LiDFOB) serves as a dual-functional initiator, concurrently inducing 1,3-dioxolane (DOL) polymerization to stabilize the electrolyte matrix while forming a protective LiF/LiBFₓ-rich interphase at electrode surfaces. Besides, the in-situ formed poly-DOL network effectively modulates solvation structures through strong anion immobilization, thereby promoting Li⁺ conduction and improving the ionic conductivity to 3.6 × 10^-4 S cm^-1. Attribute to the above merits, the synergistic effects of this design electrolyte enable unprecedented electrochemical stability, with Li/Li symmetric cells achieving stable cycling for over 1000 h at room temperature and exceeding 1500 h at 60 °C while maintaining minimal polarization. This work provides a groundbreaking approach to designing advanced electrolytes through molecular engineering, paving the way for long-cycling and high-energy-density lithium metal batteries.