SPPEK/WO3 hybrid membrane fabricated via hydrothermal method for vanadium redox flow battery

A SPPEK/WO3 hybrid membrane was fabricated by a hydrothermal method to improve its performance in vanadium redox flow battery (VRB). The morphology of the hybrid membrane revealed that WO3 phase was well formed in the SPPEK matrix. At 50 mA/cm2, the VRB single cell with SPPEK/WO3 membrane presented a lower self-discharge rate (218 h above 0.8 V) and a higher coulombic and energy efficiency (98.07% and 78.06%), ascribed to its higher ionic selectivity (5.81 × 104 min S/cm3), compared with Nafion system. The hybrid membrane exhibited a stable performance during 100 cycles.

► A SPPEK/WO3 membrane was fabricated by hydrothermal method and first investigated in VRB application.
► The introduction of WO3 can improve the ion selectivity.
► The VRB with hybrid membrane exhibited superior performance compared with SPPEK and Nafion membranes.