Solvent treatment has been proved to be a very simple and effective method to prepare high-performance porous membranes for flow batteries. However, the initial morphology and the properties of membrane materials will exert pivotal effects on the resultant performance of porous membranes. In this paper, according to comparing the differences in the morphology and performance of untreated and treated porous poly(ether sulfone) (PES) membranes with different porous structures, the influence of the initial morphology of membranes was clarified in detail. Moreover, the differences in the morphology and performance of untreated and treated porous poly (vinylidene fluoride) (PVDF), polusulfone (PSF) and poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) membranes were also investigated. By comparing various properties of PES, PVDF, PSF and PVDF-HFP polymers, the importance and criteria for selecting proper membrane materials when using the solvent treatment method were clarified. Furthermore, the VFB assembled with the resultant membrane could achieve an energy efficiency of 82.93% at 80 mA cm(-2), which could be comparable to that of the commercial Nafion 115. Therefore, this article is beneficial for designing high-performance porous membranes for flow batteries.