高离子电导率聚离子液体基自修复固态电解质的制备  

Preparation of Poly(ionic liquid)-Based Solid Electrolytes with High Ionic Conductivity and Self-Healing Behavior

作　　者：李磊[1] 刘港 牛艳华[1] 李光宪[1] Lei Li;Gang Liu;Yanhua Niu;Guangxian Li(College of Polymer Science and Engineering,State Key Laboratory of Polymer Materials Engineering of China,Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学高分子科学与工程学院高分子材料工程国家重点实验室(四川大学),四川成都610065

出　　处：《高分子材料科学与工程》2023年第7期113-122,共10页Polymer Materials Science & Engineering

基　　金：国家自然科学基金资助项目(52073184)。

摘　　要：采用可逆加成-断裂链转移(RAFT)聚合法成功合成了高分子量、窄分布的聚[1-(4-乙烯基苄基)-3-甲基咪唑双三氟甲烷磺酰亚胺](P[VBMIM][TFSI]),并将其与双三氟甲烷磺酰亚胺锂(LiTFSI)共混,通过溶液浇筑法制备了固态聚合物电解质(SPEs)。首先通过力学性能、流变学、热分析和电化学测试研究了P[VBMIM][TFSI]本体结构与性能的关系。随相对分子质量增加,P[VBMIM][TFSI]缠结程度逐渐加深,拉伸强度大幅度提升,而离子电导率与热降解温度变化不大。进一步对固态聚合物电解质进行更深入的电化学测试和分析。结果表明,SPEs在30℃时离子电导率最高可达到4.06×10^(-4) S/cm,锂离子迁移数为0.34,电化学窗口达到了4.5V。通过光学显微镜观察其自修复性,SPEs在室温时20min便可平复表面划痕,且具备良好的弹性,可以在5min内几乎完全回复拉伸长度。Poly[1-(4-vinylbenzyl)-3-methylimidazolium bis(trifluoromethanesulfonyl)imide](P[VBMIM][TFSI])with high molecular weight and narrow-molecular-weight distribution was successfully synthesized by reversible addition-fragmentation chain-transfer(RAFT)polymerization and blended with lithium bis(trifluoromethanesulfonyl)imide(LiTFSI)to prepare solid polymer electrolytes(SPEs)by solution casting method.The relationship between the structure and properties of P[VBMIM][TFSI]was investigated by mechanical property tests,rheological tests,thermal analysis and electrochemical tests.With increasing molecular weight,the degree of P[VBMIM][TFSF]entanglement gradually deepens and the tensile strength increases significantly,while the ionic conductivity and thermal degradation temperature do not change much.In-depth electrochemical testing and analysis for the SPEs show that excellent electrochemical properties have been obtained,for example,a maximum ionic conductivity of 4.06×10^(−4) S/cmat 30℃,a lithium-ion transference number of 0.34,and an electrochemical window of 4.5 V are reached.The self-healing properties were observed by optical microscopy.SPEs can smooth out surface scratches in 20 min at room temperature and have good elasticity to almost completely return to the tensile length within 5 min.

关 键 词：可逆加成-断裂链转移 聚离子液体 缠结 固态聚合物电解质 离子电导率 

分 类 号：TM912[电气工程—电力电子与电力传动]