一种用于锂离子电池的无机复合隔膜

Inorganic composite membrane as the separator of lithium ion battery

为了替代传统的聚烯烃微孔膜,对用于锂离子电池的Al2O3/SiO2/PAN(聚丙烯腈)复合隔膜进行了研究。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,膜极易传导锂离子。膜中Al2O3/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,也显示出良好的倍率放电性和耐过充电保护性能。

The Al2O3/SiO2/PAN composite membrane was prepared as the separator for Li-ion batteries in order to replace the traditional microporous polyolefin membrane. The composite membrane has high porosity, and can be well wetted by the liquid electrolyte. The ion conductivity of the membrane is easily achieved by absorbing the liquid electrolyte due to the high capillary effect. The amphoteric character of Al2 O3/SiO2 can scavenge acidic hydrogen fluoride, which is inevitably present in the LiPF6-based electrolytes used currently in the Li-ion batteries. With the composite membrane as a separator, the graphite/cathode cell exhibited a good capacity retention. It is also found that the Li-ion cell fabricated in this manner not only has stable capacity retention and high temperature safety , but also shows good high-rate performance and overcharge proof performance.