Highly Conductive and Supertough PVDF‐Based Electrolytes with Self‐Defective Fillers for Solid‐State Lithium Metal Batteries

Abstract Advanced PVDF‐based electrolytes with ceramic‐like ion migration behavior, near‐separator‐level toughness, and excellent oxidation resistance are critical for the practical implementation of solid‐state lithium‐metal batteries (SSLMBs). However, the superior ion conductivity, robust mechanical property, and wide electrochemical stability usually cannot be achieved simultaneously. Herein, the self‐defective silicon (Si) fillers with silicon/silicon oxide (Si/SiO x ,0<x≤2) heterogeneous interfaces are doped into the PVDF matrix to construct the highly conductive and supertough PVDF‐based electrolytes. Results reveal that the self‐defective Si will spontaneously participate in the Li + ‐solvation state and convert all solvation structure into the Li + ‐[solvent] x ‐[anion] y (x≤y) configuration. The anion‐rich Li + coordination environment not only accelerate Li + diffusion rate but also promotes the formation of the anion‐dominated bilayer interphase. Meanwhile, the strong Lewis acid‐base interaction of PVDF/SiO x interface effectively suppresses phase separation initiated by uneven solvent evaporation. Benefiting from the modified Li + transport environment and phase regulation, the obtained electrolytes exhibit impressive comprehensive properties, including ionic conductivity of 0.44 mS cm −1 , tensile strength of 16.5 Mpa, and voltage window of 5.07 V. Besides, the Li||Li symmetrical batteries present outstanding cycling under the current density of 0.1 mA cm −2 (>6200 h), and the LFP||Li batteries exhibit remarkable fast‐charging behavior at 10 C with the capacity retention of 82.29%.