Sulfonation of Poly(phenylene oxide) Anion Exchange Membrane for All Vanadium Flow Redox Battery

摘要

To develop a low cost non-fluorinated membrane for vanadium redox flow battery (VRFB), severalcommercial ion exchange membranes (IEM) were compared in terms of primary properties such as ionexchange capacity (IEC), vanadium ion permeability (P) and water transfer (WT) and chemicalstability, and an anion exchange membrane (AEM) DF-a (based on Poly(phenylene oxide) polymers)was sulfonated into amphoteric ion exchange membranes (DF-a1 and DF-a2) to restrain WT. Effects ofsulfonation on morphologies, selective proton conductivity (σ), WT and chemical stability ofmembranes were investigated. The results showed that sulfonation can improve IEC, σ, Selectivity andchemical stability of the AEM (DF-a). Due to Donnan effect, DF-a2 had a more dramatic reduction inWT and self discharge in VRFB than DF-a. Cell test showed that the membrane DF-a2 had highercoulombic efficiency (CE) and energy efficiency (EE) than DF-a and DF-a1, possessing a betterpotential application in VRFB.