Porous poly (ether sulfone) membranes with tunable morphology: Fabrication and their application for vanadium flow battery

Poly (ether sulfone) (PES) porous membranes with tunable morphology are prepared via phase inversion method and first investigated in vanadium flow battery (VFB) application. The morphology of PES membranes is adjusted via introducing hydrophilic poly (vinyl pyrrolidone) (PVP) in PES cast solutions. The effect of PVP (content, molecular weight) on the membranes morphology as well as their performance in VFB is studied in detail. The results show that: the addition of PVP in cast solutions could induce membranes with more porous structures and bigger pore size distribution. Therefore under VFB operating condition, the membranes show lower area resistance and higher ions permeability. As a result, the VFBs fabricated with the membranes show relatively higher voltage efficiency and lower coulombic efficiency. Thus the membranes with controlled performance in VFB can be realized via adjusting their morphology. This paper provides an effective way to optimize fabrication parameters of porous membranes for VFB application.

► PES porous membranes with tunable morphology were fabricated for VFB application.
► The morphology of PES membranes can be easily tuned via addition of PVP in solutions.
► The membranes performance in VFB can be optimized via adjusting their morphology.
► PES porous membranes show very good prospective usages in VFB.