US Patent 10147974 Battery separator membrane and battery employing same

A battery comprises an ion-conducting polymeric composition comprising a copolymer of styrene and vinylbenzyl-Rs, where Rs is a positively charged cyclic amine group. The ion-conducting polymeric composition can be in the form of a membrane. The ion-conducting polymeric composition can comprise a terpolymer of styrene, vinylbenzyl-Rs and vinylbenzyl-Rx, in which Rs is a positively charged cyclic amine group, Rx is at least one constituent selected from the group consisting of Cl, OH, and a reaction product between an OH or a Cl and a species other than a cyclic amine or a simple amine, the total weight of the vinylbenzyl-Rx groups is greater than 1% of the total weight of the membrane, and the total weight of the vinylbenzyl-Rs groups is 15% or more of the total weight of the membrane.