Nanofiltration membranes for vanadium flow battery application

Exploring advanced membranes for vanadium flow battery (VFB) application is the vital tasks for its further development. In order to solve this problem, nanofiltration (NF) membranes with tunable porous structure were first studied for VFB application. Because the NF membrane could separate vanadium ions and hydrogen ions by their difference in size, charge density as well as transporting speed in electrolyte, the NF membranes are quite capable as the next generation separators for VFBs. In our work, NF membranes with different materials (as PSF, PEEK, PES and PAN) and unique structure (as connected pores, closed posed) were prepared through normal phase inversion method. The membrane structure was well controlled with several kinds of minerals (like silica, titanium) and macromolecule additives (like PEG, PVP). The results show that the NF membrane is quite promising as the next generation separator of VFB batteries.