Polyvinylidene fluoride (PVDF) porous membrane was prepared by immersion phase inversion method and filled with SiO2@ phosphotungstic acid (HPA) nanoparticles synthesized by in-situ gel sol methods. The structure and electrochemical properties of the membranes were characterized by scanning electron microscope, electrochemical workstation, charge and discharge device, etc. The results show that, compared with the pristine PVDF membrane, the vanadium ion selectivity of the porous membranes modified by nanoparticles are obviously improved. In addition, the charge-discharge efficiency of PVDF/SiO...