A novel Nafion-g-PSBMA membrane prepared by grafting zwitterionic SBMA onto Nafion via SI-ATRP for vanadium redox flow battery application

A novel N115-g-PSBMA membrane containing zwitterionic groups was successfully prepared by grafting the zwitterionic SBMA (sulfobetaine methacrylate) onto Nafion 115 (N115) via SI-ATRP (surface-initiated atom transfer radical polymerization) technique. The N115-g-PSBMA membrane has shown higher hydrophilicity , lower vanadium permeability, higher coulombic efficiency and energy efficiency than that of commercial N115 membrane for VRB (vanadium redox flow battery) application. At the current density of 40–80 mA cm −2 , the average energy efficiency of the VRB with N115-g-PSBMA membrane has reached up to 87.3%, which is 2.6% higher than that of the VRB with N115 membrane at the same current densities. The method is expected to present a new direction to prepare novel separators with both excellent performances and low cost for VRB application.