陶瓷涂层隔膜改性锂离子电池隔膜

Ceramic Coated Diaphragm Modified Lithium Ion Battery Diaphragm

以聚乙烯(PE)湿法膜为基体,在其两侧均匀涂覆氧化铝(Al2O3)颗粒,得到一种复合涂层PE锂离子电池隔膜。对复合隔膜的形貌、透气性、吸液率和热稳定性进行了研究,结果表明:Al2O3涂层均匀涂布于PE膜表面,在105℃下放置1h,复合PE膜没有出现较大的热收缩,同PE非涂覆膜相比具有优越的热稳定性能,可以有效提高锂离子电池的热安全性能。并且混合颗粒具有较高的比表面积,使得涂覆膜对电解液的吸液率高。以Al_2O_3复合PE膜做为隔膜组装电池并进行分析表明,隔膜的离子电导率升高,并且可以显著提高长期充放电循环时电池容量保持率。

Coating separators were prepared by coating both sides of porous polyethylene（ PE） membranes with aluminum oxide（ Al2O3）. The morphology study showed that uniform coating layers were formed on the PE separators. Compared with the PE separator,the thermal stability of the composite separators was improved greatly. Meanwhile,a higher amount of electrolyte solution is expected to be retained by the composite separator. By using the Al2O3 coated PE separator,lithium-ion cells were assembled and AC impedance spectroscopy was used to characterize the impedance. The cycling performance of cells was evaluated,and were proven to be having better capacity retention than the cells prepared with polyolefin membrane.