▎ 摘　　要

A highly ion-selective membrane for vanadium redox flow batteries (VRBs) consisting of sulfonated poly(arylene ether ketone) (SPAEK) and polyoxometalate coupled with a graphene oxide was designed and fabricated. The SPAEK/PW-mGO composite membrane showed an effectively low self-discharge rate and excellent Coulombic efficiency (98.73%) in VRBs.