Fluorination‐Decoupling MOFs for Enhanced Solvation Dynamics and Interface Stability in Lithium Metal Batteries

Abstract Persistent interfacial instability remains a critical bottleneck for solid‐state lithium metal batteries, necessitating electrolyte designs that simultaneously regulate bulk transport and interfacial reactions. A fluorination‐decoupling strategy is proposed by integrating fluorinated metal–organic frameworks (MOFs) with Lewis‐acidic sites into PVDF‐HFP quasi‐solid‐state electrolytes to tailor Li ⁺ solvation dynamics and induce robust interfacial protection. Experimental results confirmed that the electron‑withdrawing and sterically bulky fluorinated moieties disrupted the metal–oxygen coordination environment and enhanced the Lewis acidity of the MOF. These modifications limited anion mobility, promoted ion‑pair dissociation, and weakened Li ⁺ coordination. Moreover, preferential interactions with fluorosilane facilitated the formation of a solid electrolyte interphase rich in LiF without compromising bulk conductivity (1.16 × 10 ⁻³ S cm ⁻¹ at 30 °C). These mechanistic insights translated into outstanding cycling stability: Li||Li symmetric cells operated stably for over 2200 h at 0.2 mA cm ⁻² , while Li||LiFePO ₄ and Li||NCM811 retained 93.5% and 70.0% capacity after 2000 and 450 cycles at 20C and 5C, respectively. This study provides a new avenue to tailor Li ⁺ solvation and improves interfacial stability in solid‐state electrolytes by precise control of fluorine–framework interactions.