Diaphragm, preparation method thereof and lithium ion battery containing diaphragm

The invention provides a diaphragm, a preparation method thereof and a lithium ion battery containing the diaphragm. The diaphragm comprises a framework part and a filling material filled in the framework part, the material of the framework part is poly-p-phenylene terephthamide fibers, and the filling material comprises ultra-high molecular weight polyethylene; the mass ratio of the poly-p-phenylene terephthamide fibers to the ultra-high molecular weight polyethylene is (0.5-3): 1. According to the diaphragm disclosed by the invention, the thermal stability and compatibility of the diaphragm are greatly improved through combination of a specific material and a specific structure. 本发明提供了一种隔膜、其制备方法和含其的锂离子电池。本发明的隔膜包括骨架部和填充在骨架部中的填充材料，所述骨架部的材料为聚对苯二甲酰对苯二胺纤维，所述填充材料包括超高分子量聚乙烯；所述聚对苯二甲酰对苯二胺纤维与所述超高分子量聚乙烯的质量比为(0.5~3)：1。本发明的隔膜通过特定材料和特定结构的结合，大大提高了隔膜的热稳定性和相容性。