Anchored Fluoro-Shielded Solvation for Lithium Metal Batteries

Polyvinylidene fluoride (PVDF)-based polymer electrolytes are promising candidates for solid-state lithium metal batteries owing to their favorable overall electrochemical properties. However, conventional PVDF-based polymer electrolytes suffer from uneven solvation distribution, discontinuous ion-transport pathways, and unstable electrode/electrolyte interfaces caused by residual solvents and porous PVDF frameworks. Herein, we report an anchored fluoro-shielded solvation strategy to construct a high-performance PVDF-based polymer electrolyte. By integrating polyanionic anchoring sites with fluorinated shielding segments, the optimized electrolyte enables spatially distributed anion-rich solvation pathways, homogeneous Li⁺ transport, and robust LiF-rich solid electrolyte interphase (SEI). The polymer electrolyte delivers a high ionic conductivity of 1.26×10^-3 S cm^-1, a Li⁺ transference number of 0.69, an oxidative onset potential of 5.27 V, and a critical current density of 6.4 mA cm^-2. Spectroscopic and interfacial analyses reveal that the anchored fluoro-shielded solvation structure promotes LiF-rich SEI formation and suppresses solvent decomposition. Consequently, Li||LiNi_0.8Co_0.1Mn_0.1O₂ batteries retain 80.2% capacity after 2000 cycles under high-voltage and high-rate conditions of 4.5 V and 5 C. This work highlights anchored fluoro-shielded solvation as an effective molecular design principle for advanced polymer electrolytes toward practical high-voltage and high-rate solid-state Li metal batteries.