拉伸率对聚乙烯隔膜性能的影响  

Effect of stretching ratio on the performance of polyethylene separators

作　　者：王欣 陈红辉 吴一帆 喻鹏[1] WANG Xin;CHEN Hong-hui;WU Yi-fan;YU Peng(College of Chemistry and Materials Science,Hunan Agricultural University,Changsha,Hunan 410128,China;Hunan Chinaly New Material Co.,Ltd.,Changde,Hunan 415000,China)

机构地区：[1]湖南农业大学化学与材料科学学院,湖南长沙410128 [2]湖南中锂新材料有限公司,湖南常德415000

出　　处：《电池》2021年第4期338-341,共4页Battery Bimonthly

基　　金：湖南省大学生创新创业训练计划项目(S202010537021)。

摘　　要：在5.5%~7.0%设置不同纵向和横向拉伸率组合,研究拉伸率对湿法双向拉伸聚乙烯隔膜抗拉强度、透气性、热收缩性和孔径形貌等性能的影响,并进行电池性能测试,以获得综合性能最优的参数。纵向和横向拉伸率越大,隔膜的抗拉强度、透气性越好,但热收缩性却越差,其中横向6.0%、纵向6.5%且极差率大于0.5%时,隔膜材料的纵向、横向抗拉强度分别为165 MPa、160 MPa,热收缩率低于2%、孔隙率均匀完整。使用该隔膜的电池,在电流为0.2 C、0.5 C、1.0 C、2.0 C和5.0 C时的放电比容量分别为158 mAh/g、152 mAh/g、144 mAh/g、134 mAh/g和121 mAh/g,具有相对较高的放电比容量和较好的倍率性能。Different longitudinal and transverse stretching ratio combinations were set between 5.5% and 7.0%to study the effects of tensile rate on the tensile strength,air permeability,thermal shrinkage,pore morphology and other properties of wet biaxially stretched polyethylene separators.The battery performance test was carried out to obtain the optimum parameters.The tensile strength and permeability of the separators were better with the increase of longitudinal and transverse tensile ratio,but the thermal shrinkage of the separators was worse.When the tensile ratio was 6.0% in the transverse direction and 6.5% in the longitudinal direction,the range ratio was more than 0.5%,the longitudinal and transverse tensile strength of the diaphragm materials was 165 MPa and 160 MPa,respectively,thermal shrinkage was less than 2% and the porosity was uniform and complete.When the current was 0.2 C,0.5 C,1.0 C,2.0 C and 5.0 C,the specific discharge capacity of the battery using the separator was 158 mAh/g,152 mAh/g,144 mAh/g,134 mAh/g and 121 mAh/g,respectively,which had relatively high specific discharge capacity and good rate capability.

关 键 词：拉伸率 聚乙烯隔膜 双向拉伸 锂离子电池 抗拉强度 透气性 热收缩性 

分 类 号：TM912.9[电气工程—电力电子与电力传动]