锂离子电池用陶瓷聚烯烃复合隔膜

A Polyolefin /Ceramic Composite Membrane for Lithium Ion Batteries

为改善聚烯烃微孔膜的耐热安全性,研究了用于锂离子电池的陶瓷聚烯烃复合隔膜ZrO2/SiO2/PP(聚丙烯)。复合膜具有高度多孔性和良好液体电解液湿润性。由于高的毛细吸附作用,通过吸附液态电解液,膜很易传导锂离子。膜中ZrO2/SiO2的两性特征,将电解液中的酸性HF(氟化氢)消耗掉,而HF作为现在锂离子电池所用电解液中的杂质是不可避免的。复合膜作为隔膜制备的碳/正极材料锂离子电池不仅具有优良的容量保持性、高温安全性,也显示良好的倍率放电性。

A polyolefin/ceramic composite membrane,ZrO2/SiO2/PP （PP：polypropylene）,was prepared as the separator for Li-ion batteries in order to replace the traditional microporous polyolefin membrane.The polyolefin/ceramic composite membrane has high porosity,and can be well wetted by the liquid electrolyte.The ion conductivity of membrane is easily achieved by absorbing the liquid electrolyte due to the high capillary effect.The amphoteric character of ZrO2/SiO2 can scavenge acidic hydrogen fluoride,which is inevitably present in the LiPF6-based electrolytes used currently in the Li-ion batteries.With the polyolefin/ ceramic composite membrane as a separator,the graphite/cathode cell exhibits good capacity retention.It is also found that the Li-ion cell fabricated in this manner not only has stable capacity retention,better high temperature performance,but also shows good high-rate performance.