锂离子电池用PVDF/P(MMA-co-DMAEMA)共混隔膜的制备与性能  

Preparation and characterization of PVDF/P(MMA-co-DMAEMA) separators for lithium battery

作　　者：刘卫东[1,2] 李浩[1] 姚之侃[1] 王婷[1] 朱宝库[1] 朱利平[1] 

机构地区：[1]浙江大学高分子科学与工程学系,教育部高分子合成与功能构造重点实验室,浙江杭州310027 [2]浙江师范大学化学与生命科学学院,浙江金华321004

出　　处：《功能材料》2012年第11期1364-1368,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(U1134002;20974094);国家重点基础研究发展计划(973计划)资助项目(2009CB623402)

摘　　要：首先合成了甲基丙烯酸甲酯(MMA)与甲基丙烯酸-N,N-二甲胺乙酯的共聚物P(MMA-co-DMAE-MA),与聚偏氟乙烯(PVDF)共混经溶液相转化法制备了PVDF/P(MMA-co-DMAEMA)隔膜。研究发现,相对于纯PVDF隔膜,共混隔膜的孔隙率增加,结晶度降低,电解液吸收稳定性显著提高。共混隔膜具有"活性"隔膜的性质,隔膜-电解液组成的电解质体系表现出凝胶电解质特征,隔膜中PVDF/P(MMA-co-DMAE-MA)质量比为10/1时,隔膜吸液率在420%以上,活化后凝胶电解质膜离子电导率可达到1.8×10-3S/cm。研究结果表明,采用溶液相转化法制备PVDF/P(MMA-co-DMAEMA)共混隔膜,是一种制备凝胶锂离子电池用高性能活性隔膜的有效方法。Lithium ion conducting membranes based on porous separators are the key materials for high performance lithium ion batteries.The amphiphilic copolymers of poly（methyl methacrylate-co-dimethylaminoethyl methacrylate）（P（MMA-co-DMAEMA）） were synthesized through a conventional radical polymerization.Using these copolymers as additives in casting solutions,the PVDF/P（MMA-co-DMAEMA） porous blend membranes were prepared following a typical non-solvent induced phase separation（NIPS） process.Compared with pure PVDF separator with comparable porous structure,the adoption of P（MMA-co-DMAEMA） could not only decrease the crystallinity,but also enhance the stability of entrapped liquid electrolyte.Such modified PVDF membrane should be named as ＂active separator＂,which can exhibit the characteristic of gel electrolyte by absorbing lithium salt liquid electrolyte.For separators with PVDF/P（MMA-co-DMAEMA） mass ratio in 10∶1,the liquid electrolyte uptake reached above 420wt% and ion conductivity of the membrane was 1.8× 10-3S/cm,which was acceptable for high voltage lithium ion batteries.These results primarily indicate the potential of the prepared blend separator in real application in safe and high performance lithium ion batteries.

关 键 词：锂离子电池 隔膜 聚偏氟乙烯 共混 电导率 

分 类 号：TM911.3[电气工程—电力电子与电力传动]