基于多孔PVDF接枝单离子传导聚合物的增强型、抗渗漏凝胶电解质

项目名称： 基于多孔PVDF接枝单离子传导聚合物的增强型、抗渗漏凝胶电解质

项目编号： No.51203055

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 有机高分子材料学科

项目作者： 王晓恩

作者单位： 华中科技大学

项目金额： 25万元

中文摘要： 如何同时提高离子电导率和力学强度是高性能锂离子电池聚合物电解质制备的关键。本项目拟设计一种结构新颖、离子电导率与力学性能兼优的高性能凝胶电解质。首先合成单离子传导型丙烯酸酯类聚合物单体，通过原子转移自由基聚合反应将聚合物单体接枝到聚偏氟乙烯(PVDF)主链上,并采用相反转法制备具有单离子传导功能的多孔膜。然后将含山梨醇缩醛(DBS)类凝胶因子和锂盐的聚乙二醇二甲醚溶液浸渍到多孔膜中,原位凝胶化形成离子传导相。其中，单离子传导的多孔膜既能实现对凝胶电解质的力学增强，又能有效提高离子迁移数。凝胶相的存在使凝胶电解质既能保持类似液态电解质的高电导率，又能消除溶剂渗漏。本项目将系统研究PVDF接枝率、接枝侧链聚合度等对聚合物基体孔形貌和力学性能的影响，以及DBS凝胶因子存在下电解质的凝胶化行为与离子传导特性，为制备具有高电导率、高离子迁移数和高强度的聚合物电解质材料提供新的设计思路和研究方法。

中文关键词： 聚合物电解质；离子电导率；锂离子电池；聚偏氟乙烯；电解液泄漏

英文摘要： It is essential to improve the ionic conductivity together with mechanical properties for high performance polymer electrolytes of lithium ion batteries. In this project,a novel method is developed to prepare high performance gel polymer electrolytes with high ionic conductivity and improved mechanical properties. First,acrylate-based single-ion conductive polymers are synthesized and designed to graft onto the main chain of poly(vinylidene fluoride)(PVDF) by atom transfer radical polymerization. Then,the porous membrane based on the modified PVDF is prepared by phase inversion, and subsequently the poly(ethylene glycol) dimethyl ether solution with lithium slats and gelators is impregnented into the micropores of polymer membrane to form ion conductive gel phase by in-situ gelation. In the gel polymer electrolyte, the porous membrane can improve the mechanical properties and the ion transference number. Meanwhile, the formation of gel phase can eliminate solvents leakage and maintain liquid-like transport behaviors resulting in high ionic conductivity. The influences of grafting degree, polymerization degree of the side chain on the structure and the mechanical properties of modified PVDF membranes will be investigated. The gelation behaviors and the ion transport mechanism of the novel gel polymer electrolyte

英文关键词： polymer electrolyte；ionic conductivity；lithium ion batteries；PVDF；electrolyte leakage