无机复合锂离子电池隔膜的制备及性能研究  

Preparation and Performance of Inorganic Composite Separators for Lithium-ion Battery

作　　者：胡志宇[1] 李利平[1] 周建军[1] 李林[1] 

机构地区：[1]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1288-1293,共6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项目

摘　　要：用氧化铝(Al2O3)、硫酸钡(Ba SO4)、锆钛酸铅(PZT)、二氧化钛(Ti O2)、气相二氧化硅R202(RSi O2)、A380(ASi O2)和沉淀相二氧化硅(PSSi O2)7种无机纳米材料制备成分散液,在单向拉伸聚丙烯(PP)隔膜表面单面涂覆制备了复合隔膜.对复合隔膜的形貌、透气性及热稳定性进行了研究,并通过线性扫描曲线和不同倍率下电池充放电循环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.结果表明,7种复合隔膜与空白PP隔膜相比,在140℃下的热收缩率均减小1倍以上,表明其中无机纳米材料对PP隔膜的热收缩性能有很大改善.电池循环性能研究表明,这几种复合隔膜电池循环性能都有不同程度的提高,且在较高倍率下依旧可以发挥优势(ASi O2涂层复合隔膜除外).ASi O2涂层复合隔膜电池在2 C高倍率放电时容量快速衰减,其原因可能是ASi O2过大的比表面积增加了锂离子迁移的阻力.Seven kinds of polypropylene （PP） composite separators were prepared by coating PP separators with inorganic particles such as aluminum oxide （A1203 ）, barium sulfate （BaSO4 ）, lead zirconate titanate （PZT） , titanium dioxide （TiO2 ） , fumed silica R202 （ Rsio2 ） , A380 （ Asio2 ） and precipitated silica （ PSsio2 ）. The morphology study showed that uniform coating layers were formed on the PP separators. Compared with the bare PP separator,the permeability of the composite separators decreased a little,while the thermal stability improved greatly. The effects of coating layer on the electrochemical stability of the electrolyte were also investigated by linear sweep voltammetry （LSV） and it was found that the coating material didn＇ t deteriorated the performance of the electrolyte. The cycling performance of the cells showed that the capacity of cells increased by more than 20 mAh/g for almost all kinds of composite separators and could retain the advantage at a high discharge rates of 2 C （except for Asio=）. However, for the cells with Asio2 composite separators, the capacity decayed very rapidly at the rate of 2 C. We attributed the rapid capacity decay to the too large specific surface area and lots of silicon hydroxyls on the surface of Asio2 ,which increased the transport resistance of the lithium ion.

关 键 词：锂离子电池 无机涂层 复合隔膜 

分 类 号：TM912[电气工程—电力电子与电力传动]