Patent ID: 7893117

Claim:
An ion-conducting, sulfonated and crosslinked copolymer comprising: a first monomer comprising an aromatic diol; a second monomer comprising two groups, each group capable of reacting with hydroxy groups of the first monomer and each group independently selected from a nitro group and a halogen group; a third monomer comprising one of the first monomer or the second monomer wherein a hydrogen atom attached to a benzene ring is substituted with —SO 3 Y, where Y is selected from hydrogen (H), lithium (Li), sodium (Na), potassium (K) or trialkyl ammonium of the form HNR 3 where R is an alkyl group having from 1 to 5 carbon atoms; and a fourth monomer comprising at least three groups independently selected from a hydroxy group, a nitro group, and a halogen group.