功能性COF-Br-SO3Li材料的制备及锂离子传导性能研究OA

Covalent organic frameworks(COFs),owing to their structural designability,excellent thermal and chemical stability and ordered pore channels,exhibit great potential as matrix materials for solid-state electrolytes.However,existing sulfonic acid-functionalized COF-based solid-state electrolyte materials possess relatively simple structures,which limit their further performance enhancement.COF-Br containing bromine anchoring sites was synthesized via a solvothermal method.Through a Williamson ether synthesis reaction,sulfonic acid functional groups were successfully introduced,leading to the preparation of the functional COF-Br-SO3Li material.By compositing COF-Br-SO3Li with polyethylene oxide(PEO),a novel composite solid-state electrolyte film was obtained.Characterization results from XRD,FT-IR and TGA confirm that the prepared COFs possess good crystallinity,porosity and thermal stability.Electrochemical measurements demonstrate that at 30℃,the lithium-ion conductivity of the COF-Br-SO3Li solid-state electrolyte reaches 2.5×10-5 S/cm,with an activation energy of 0.25 eV,an electrochemical stability window extending up to 5.2 V and a lithium-ion transference number of 0.65.During the lithium symmetric cell cycling test(500 h),the solid-state electrolyte exhibits excellent interfacial stability and outstanding capability to suppress lithium dendrite growth.