BATTERY SEPARATOR AND PREPARATION METHOD THEREFOR, AND BATTERY

The present application provides a battery separator and a preparation method therefor, and a battery. The battery separator provided by the present application comprises a base film and a coating coated on one or both sides of the base film, wherein the coating comprises: fluorine-free polymer resin particles and ceramic particles; wherein the fluorine-free polymer resin particles have a primary particle morphology or a secondary agglomerate morphology, and the fluorine-free polymer resin particles in spherical form are dispersed within the ceramic particles, and a coating surface density ρ, a coating thickness h, an average radius r of fluorine-free polymer resin particles, a volume Vi occupied by fluorine-free polymer resin particles in the coating, a number N0 of fluorine-free polymer resin particles, a density ρ of fluorine-free polymer resin, and a coating density pi of pure ceramic coating satisfy the following relationship. The battery separator provided by the present application has a coating with good bonding property, high consistency, high stability, and good heat resistance.