Amphiphilic block copolymer membrane for vanadium redox flow battery
By Wang, Fei; Sylvia, James M.; Jacob, Monsy M. & Peramunage, Dharmasena
Published in Journal of Power Sources
2013
Abstract
An amphiphilic block copolymer comprised of hydrophobic polyaryletherketone (PAEK) and hydrophilic sulfonated polyaryletherketone (SPAEK) blocks has been synthesized and characterized. A membrane prepared from the block copolymer is used as the separator in a single cell vanadium redox flow battery (VRB). The proton conductivity, mechanical property, VO2+ permeability and single VRB cell performance of this block copolymer membrane are investigated and compared to Nafionâ„¢ 117. The block copolymer membrane showed significantly improved vanadium ion selectivity, higher mechanical strength and lower conductivity than Nafionâ„¢ 117. The VRB containing the block copolymer membrane exhibits higher coulombic efficiency and similar energy efficiency compared to a VRB using Nafionâ„¢ 117. The better vanadium ion selectivity of the block copolymer membrane has led to a much smaller capacity loss during 50 charge–discharge cycles for the VRB.