Composite separator, preparation method thereof and secondary battery containing the composite separator

Abstract

Provided are a composite separator, which includes: a first base film, a second base film, and a coating disposes between the first base film and the second base film, a peel force between the first base film and the coating is equal to or higher than 10 N/mm; and/or a peel force between the second base film and the coating is equal to or higher than 10 N/mm. By configuring the composite separator of the present application as a structure of first base film-coating-second base film, the mechanical strength of the composite separator can be effectively maintained, the peeling performance can be ensured, thereby effectively increasing the heat resistance, reducing the influence of thermal effects on the composite separator, and ensuring the safety of the battery over an extended period of use.

Dependencies are inferred from the claim text.