Structural effects of anion exchange composite membranes in non-aqueous redox flow batteries

The coulombic efficiency (CE) and energy efficiency (EE) of the RFBs with charged-porous composite membranes were 90.7% and 76.2%, respectively; the CE and EE values were 79.0% and 68.7% for the non-aqueous Fe-Ni RFBs with thin-layered composite membranes, at a current density of 0.5 mA cm-2, which are higher than those obtained with a commercial FAP450 membrane. These results indicate that controlled porosity in an anion-exchange material on a chemically and dimensionally stable porous membrane contribute to the successful application of RFBs in energy storage systems.