A 3D interconnected functionalized metal organic framework-reinforced solid electrolyte by in-situ polymerization for stable lithium metal battery

Solid-state lithium metal batteries, with high theoretical specific capacity and safety, have received significant attention. However, issues such as uneven lithium-ion flux and lithium dendrites limit their further application. Herein, we designed a composite polymer electrolyte (CPE) prepared by electrospinning a 3D interconnected functionalized Metal Organic Framework (MOF) network loaded with fluorinated-UIO66 (FUIO66) nanoparticles and in-situ polymerization of 1,3-dioxosolane (DOL). This structure improved the conductivity of Li⁺ (3.96 × 10^–4 S cm^-1) and enhanced the resistance of high voltage (4.8 V) by promoting the generation of long-chain polyDOL (PDOL) through the strong Lewis acidity of FUIO66. In addition, the F groups in the micropore strengthened the trapping of bis(trifluoromethanesulfonyl)imide (TFSI^-) as well as the uniform deposited of LiF solid electrolyte interfaces (SEI), which facilitated the efficiency of Li⁺ conduction and limited the formation of Li dendrites. Consequently, the Li/FUIO66/PAN fiber@PDOL (FPF@PDOL)/Li battery showed good stability for 1200 h at 0.2 mA cm^-2, and the capacity retention of the prepared LiFePO₄ and LiCoO₂/Li solid-state batteries reached 91 % after 400 cycles and 82 % after 500 cycles at room temperature. This research provides a new idea for the preparation of solid electrolytes with good ion transport kinetics and interfacial compatibility.