锂离子电池有机/聚丙烯复合隔膜研究  

Investigation on the Organic/Polypropylene Composite Separators for Lithium-ion Battery

作　　者：李剑思[1] 王晶[2] 陈春海[1] 党国栋[1] 周建军[2] 李林[2] 

机构地区：[1]吉林大学化学学院麦克德尔米德实验室,长春130012 [2]北京师范大学化学学院能量储存与转换北京市重点实验室,北京100875

出　　处：《高分子学报》2015年第11期1294-1298,共5页Acta Polymerica Sinica

基　　金：国家自然科学基金(基金号21434003);中央高校基本科研业务费专项资金资助

摘　　要：以单向拉伸的PP隔膜为基膜,PVDF、PTFE、PEK-C、PES和PPSU等多种具有耐高温性能的聚合物为涂层材料,制备了有机/PP复合隔膜.对复合隔膜的形貌、透气性及热稳定性进行了研究,并考察了复合隔膜对电解液的电化学稳定性和电池循环性能的影响.研究发现,有机复合隔膜的透气性能略有降低,但热收缩性能有了明显的改善.电化学性能表明,复合隔膜在锂离子电池工作的电化学窗口性能稳定.电池循环性能发现,采用有机复合隔膜电池的放电容量普遍增加,倍率放电性能也优于使用PP隔膜的电池.Organic/PP composite separators were prepared by coating polymers （PVDF, PTFE, PEK-C, PES and PPSU） , which are of high temperature resistance, onto uniaxially stretched PP separators. The porous coating layers of PVDF,PEK-C,PES and PPSU were obtained by phase inversion method. And PTFE coating layer were formed by coating a suspension of PTFE nanoparticles. It could be found by SEM that pores were formed in the inter-particle area when the PTFE deposited on surface of the bare PP separator. The permeability and thermal stability of the composite separators were studied. It could be found that although the permeability of the organic composite separators decreased slightly, the thermal shrinkage properties could improve obviously, which meant that organic coating layers were helpful for improving the thermal stability of the composite separators. Linear sweep voltammetry was measured and showed that the composite separators were stable in the electrochemical window for lithium-ion batteries. The organic/PP composite separators were also used to assemble cells and evaluated by the charge and discharge performance. Cycle performance showed that the cells with composite separators had higher discharge capacity and better rate discharge performance than those ceils with bare PP separator. We attributed the improvement of discharge capacity and rate discharge performance to the better wetting ability of the electrolyte to the composite separators.

关 键 词：有机复合隔膜 锂离子电池 聚丙烯隔膜 

分 类 号：TQ317[化学工程—高聚物工业] TM912[电气工程—电力电子与电力传动]