COATED SEPARATOR WITH HIGH HEAT RESISTANCE AND HIGH PEEL STRENGTH AND PREPARATION METHOD THEREOF

The present invention discloses a coated separator with high heat resistance and high peel strength and a preparation method thereof. The coated separator comprises a polyolefin base membrane, and a surface of the polyolefin base membrane is coated with a ceramic coating layer. The ceramic coating layer is prepared from the following raw materials in parts by weight: 30-50 parts of ceramic powder, 0.5-2 parts of a dispersant, 3-7 parts of a prefabricated binder, 0.1-0.5 parts of a wetting agent, and 20-30 parts of high-purity water. The prefabricated binder is a mixture of modified acrylic resin and poly alpha-methyl cyanoacrylate; the modified acrylic resin is mainly prepared from 2-aminopyrimidine, vanillin, an acrylic monomer, acrylic ester, o-bromoacetophenone, and dimethyl azodiisobutyrate through multi-step reactions. Compared with the existing coated separator, the coated separator prepared in the present invention has a thinner coating layer which can be as thin as 2 µm, and has more excellent heat shrinkage resistance and good heat resistance, and due to the peel strength of the coating layer, the battery life and safety performance of a battery separator are greatly improved.