Anion exchange membranes consisting of poly-vinylpyridine- and poly-vinylbenzylchloride- for Cr/Fe Redox batteries

For application in Cr/Fe redox batteries a fouling-resistant anion exchange membrane was developed by quaternizing a 4-vinylpyridine-co-styrene copolymer with poly (vinylbenzyl chloride). One reaction generates fixed cations at the branching points of the network. Membranes with a Cl-minus permselectivity equal or bigger than 70% (0.5N/1.0 N KCI) and a specific area resistance equal or smaller than 1 Omega-qcm in Fe Cl2,/FeCl3/HCI electrolytes were synthesized. The low resistance is stable for at least 10 high 3 hours.