Study On Nafion Amphoteric Membrane For Vanadium Flow Battery Prepared By Atom Transfer Radical Polymerization

The vanadium redox flow battery?VRB?as an excellent energy storage method can effectively cooperate with new energy sources with large fluctuations in energy output.At present,the key material for VRB's performance constraints is the ion exchange membrane.Reducing the cost of the membrane and improving the performance of the membrane have a strong practical interest in the development of VRB.In this study,atom transfer radical polymerization?ATRP?was used to modify Nafion membrane with the most widely using in VRB.A kind of zwitterionic betaine monomer,methacryloylethyl sulfobetaine,was grafted on Nafion115 and Nafion212 membrane surfaces using heterogeneous surface atom transfer radical polymerization?SI-ATRP?.The Nafion membrane was characterized by Fourier transform infrared spectroscopy,scanning electron microscopy,energy dispersive spectroscopy,X-ray photoelectron spectroscopy and thermogravimetry,and tested for its physicochemical and electrochemical properties.Experiments show that both Nafion115 and Nafion212 membrane grafted with PSBMA exhibit excellent vanadium resistance.In the VRB test,the energy efficiency reached 87.3%and 87.7%,respectively,2.6%and 5.8%higher than Nafion 115/212membrane.It is proved that the grafting of SBMA on membrane surface can effectively improve the VRB performance of commercial Nafion membrane.The Nafion membrane was dissolved and the homogeneous solution ATRP reaction was used to graft methacryloylethyl sulfobetaine,Sodium p-styrenesulfonate and 2-?Methacryloyloxy?ethyl trimethylammonium chloride respectively.Three modify resins was characterized by Fourier transform infrared spectroscopy.One or both of these three resins were blended with Nafion resin,dissolved and cast into a film,obtain Nafion-gPSBMA and Nafion resin blended N-SBMA film,Nafion-g-PNaSS?x?,Nafion-g-PMETAC?y?and Nafion?z?resin blended M_x:y-z%film,characterized microscopic morphology of film Surface by scanning electron microscopy.Experiments showed that the Nafion-g-PSBMA resin accounted for 20%of the N-SBMA 20%film performance is optimal.This paper also studied the effects of different blending ratio and blending proportion of Nafion-g-PNaSS resin and Nafion-g-PMETAC resin on the performance of M_x:y-z%film.Its physicochemical and electrochemical properties were tested and compared with recast Nafion membranes of the same thickness.The experiment showed that the M_1:1-10%film which best ratio of the two modified resins was 1:1and best proportion of resins was 10%had the highest ion selectivity and the best battery performance.Finally,the advantages and disadvantages of various energy storage methods were analyzed and compared,and the preparation costs of Nafion-g-PSBMA film,N-SBMA 20%film,and M_1:1-10%film were estimated.Provide some reference opinions for the industrial production of the three kind of membrane.