Abstract: A lithium ion battery separator consists of a PE micro-porous substrate A and a micro-porous coating B which is located on the substrate A and formed of mixing pre-crosslinked rubber particles and ceramic fine powder composite materials. The separator has characteristics of good compressible elasticity, thermal shutdown, low heat shrinkage, high temperature membrane rupture resistance and so on.

Abstract: The present invention relates to a composite nano microporous diaphragm for use in lithium ion cells using polyolefin modified with post-crosslinked rubber and manufacturing method thereof. The microporous diaphragm at least comprises a nano microporous diaphragm A layer with a chemical gel content of more than 20%, the microscopic structure thereof is designed to be the rubber material that has been evenly dispersed and has subjected to a post-crosslinking treatment in polyolefin nano microfiber matrix, forming a nano microporous diaphragm of rubber-plastic composite. The nano microporous diaphragm with high strength, thermal cutoff, high temperature resistance, as well as good liquid absorption and swelling and compression elasticity can be applied to lithium ion power cells with high safety and long cycling life.