不同制造方法锂离子电池隔膜微孔结构与性能关系  

Microporous Structure and Mechanical Behavior of Lithium-Ion Battery Separators Manufactured by Different Processes

作　　者：丁磊[1] 杨锋[1] 吴桐[1] 曹亚[1] 蔡燎原[1] 向明[1] Lei Ding;Feng Yang;Tong Wu;Ya Cao;Liaoyuan Cai;Ming Xiang(State Key Laboratory of Polymer Materials Engineering,Polymer Research Institute of Sichuan University,Chengdu 610065,China)

机构地区：[1]四川大学高分子研究所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》2021年第1期118-127,共10页Polymer Materials Science & Engineering

摘　　要：文中选取目前商业化最成熟的干法单拉、干法双拉及湿法工艺制造的3种锂离子电池隔膜,通过对比3种隔膜在受到不同形式应力时的响应与破坏行为,探讨了不同制造方法制备的锂离子电池隔膜微孔结构与性能的关系。扫描电子显微镜,二维广角X射线衍射以及力学性能实验表明,干法单拉隔膜在挤出过程中的高口模拉伸比赋予隔膜强烈的各向异性,因此机械方向拉伸强度远大于其他方向,其穿刺强度最低;但干法单拉隔膜厚度方向排状片晶结构起到了支撑作用,为隔膜提供了优异的抗压缩性能。而经历过双向拉伸的2种隔膜(干法双拉和湿法)各向异性减弱,因而其穿刺强度更高。同时双向拉伸会造成隔膜厚度方向多层堆叠结构,导致厚度方向支撑或连接结构减少,从而降低隔膜的抗压缩强度,增强隔膜分层趋势。但由于湿法工艺超高的拉伸倍率导致最终隔膜的抗压缩强度最低,隔膜的分层趋势最强。Three most commonly used commercial polymer separators were selected to investigate the relationship between microstructure and performance of lithium-ion battery separators.The mechanical behavior and failure modes of separators under all probable loading conditions were compared.The scanning electron microscopy,two-dimensional wide-angle X-ray diffraction,and various performance tests show that the separator prepared by the dry process with uniaxial stretching has high anisotropy.Consequently,the tensile strength varies greatly in different directions,the puncture strength is also the lowest.But the parallel arranged lamellae on the cross-section act as support structure for the separator,causing better compression resistance and weak delamination trends.While the separators produced by the dry process with biaxial stretching and wet process have comparable strength levels when stretched in different directions and higher puncture strength.But the biaxial stretching leads to the stacked multilayer structure with poor connection or support structure along the thickness direction,causing a weaker compression resistance but stronger delamination trend.

关 键 词：锂离子电池隔膜 干法单向拉伸工艺 干法双向拉伸工艺 湿法工艺 压缩性能 穿刺强度 

分 类 号：TM912[电气工程—电力电子与电力传动]