Solvation‐Regulated PVDF Solid Polymer Electrolytes Enabled by Borates for Dendrite‐Resistant Lithium Metal Batteries

Despite their mechanical robustness and high‐voltage stability, poly(vinylidene fluoride) (PVDF) solid polymer electrolytes are hindered by sluggish Li + transport, stemming from anion‐dominated conduction and residual solvent‐induced interfacial degradation. This study addresses these issues by introducing zinc borate (ZB) as a filler into the PVDF electrolyte and preparing the composite electrolyte PVZB, thereby reconstructing the lithium‐ion solvation structure and stabilizing the electrode interface, elevating the Li + transference number to 0.49, and boosting room‐temperature ionic conductivity to 3.3 × 10 −4 S cm −1 . Crucially, a rich inorganic solid electrolyte interphase enables stable cycling of Li/PVZB/Li cells for 3000 h at 0.1 mA cm −2 . NCM811/PVZB/Li cells deliver 78.5% capacity retention after 400 cycles at 4.3 V with excellent Coulombic efficiency (99.2%).