MICROPOROUS MEMBRANE OF POLYETHYLENE-BASED COMPOSITE MATERIAL WITH ADHESION UNDER HOT PRESSING

The present invention relates to a microporous membrane of polyethylene-based composite material with adhesion under hot pressing, which utilises ethylene-propylene rubber and polyisobutene rubber with medium molecular weights to modify high density polyethylene with a high degree of crystallisation, and utilises an ester of an aliphatic dicarboxylic acid with a flash point higher than 210°C as the process solvent and pore-forming agent for the membrane, to obtain the membrane with the property of adhesion under hot pressing; the membrane is hot-pressed with a positive electrode sheet so these adhere together, and the heat shrinkage of the membrane is inhibited thereby; the composite material membrane has high strength, resistance to high temperature, and can be used in lithium ion power batteries with a high degree of safety and a long cycle life.