Modification of anion-exchange membranes for vanadium redox flow battery applications

Modification of the Selemion AMV and New Selemion (Type 2) anion-exchange membranes (Asahi Glass, Japan) has improved their water transport properties in the vanadium redox cell. The AMV membrane is sulfonated using concentrated sulfuric acid, while poly(sodium-4-styrenesulfonate) (Aldrich, USA, mol. wt. ≈ 70 000) is incorporated into the New Selemion (Type 2) membrane. A significant reduction in the amount of water transport across the membranes during operation of the vanadium redox battery is achieved.