Battery separators, coated battery separators, batteries, and related methods

Abstract

A new or improved microporous monolayer, bilayer, trilayer, or multilayer membrane, separator membrane, separator, or coated separator is disclosed. The membrane is preferably made up of at least one resin or polymer and at least one additive. The additive may comprise at least one material that improves adhesion of the microporous membrane to a coating, including a polyaramid-containing coating and a PCS coating, or to a different material such as a metallic surface, including an electrode surface. Improvements in adhesion are based on comparisons to similar microporous membranes without the at least one additive. In some preferred embodiments, the at least one additive may comprise, consist of, or consist essentially of a functionalized polymer or the combination of a functionalized polymer and an elastomer. In some embodiments, the functional group of the functionalized polymer may be maleic anhydride (MAH). Also disclosed is a battery separator or coated separator comprising the new or improved microporous membrane. The battery separator may comprise the microporous membrane coated with a polyaramid-containing coating. Also disclosed is a new or improved separator, composite, battery, secondary lithium ion battery, and/or vehicle or device comprising the separator, composite, or battery.