Poly(vinylbenzyl chloride-glycidyl methacrylate)/polyethylene composite anion exchange membranes for vanadium redox battery application

Anion exchange membranes for a vanadium redox flow battery (VRB) were prepared by pore-filling on a PE substrate with the copolymerization of vinylbenzyl chloride (VBC) and glycidyl methacrylate (GMA). The ion exchange capacity, water uptake and weight gain ratio were increased with a similar tendency up to 65% of GMA content, indicating that the monomer improved the pore-filling degree and membrane properties. The vanadium ion permeability and open-circuit voltage were also investigated. The permeability of the VG65 membrane was only 1.23 × 10-7 cm2 min?1 compared to 17.9 × 10-7 cm2 min-1 for Nafion 117 and 1.8 × 10?7 cm2 min-1 for AMV. Consequently, a VRB single cell using the prepared membrane showed higher energy efficiency (over 80%) of up to 100 cycles compared to the commercial membranes, Nafion 117 (ca. 58%) and AMV (ca. 70%).