Composite bodies used as separators in electrochemical cells

Abstract

A composite comprises at least one first layer which includes a composite comprising (a) from 1 to 99% by weight of a solid (I) with a primary particle size of from 5 nm to 100 μm or a mixture made from at least two solids, (b) from 99 to 1% by weight of a polymeric binder (II) obtainable by polymerizing b1) from 5 to 100% by weight, based on the binder (II), of a condensation product III made from at least one compound IV which is capable of reacting with a carboxylic acid or with a sulfonic acid or with a derivative or with a mixture of two or more of these, and at least one mol per mole of compound IV of a carboxylic or sulfonic acid V which has at least one functional group capable of free-radical polymerization, or of a derivative of these or of a mixture of two or more of these and b2) from 0 to 95% by weight, based on the binder (II), of another compound VII with an average molecular weight (number average) of at least 5000 having polyether segments in a main or side chain, where the at least one layer has been applied to at least one second layer comprising at least one conventional separator.

Dependencies are inferred from the claim text.