Optimizing membrane thickness for vanadium redox flow batteries

摘要: Abstract Two important intrinsic properties of proton exchange membranes for vanadium redox flow battery (VRFB) operation are conductivity and permeability. These characteristics thickness-normalized quantities depend on fundamental material parameters. However, the operational criteria in these devices membrane resistance crossover flux, both which thickness. Herein, we explore influence thickness ion capacity (IEC)-optimized sulfonated fluorinated poly(arylene ether) (SFPAE) their VRFB performance including charge/discharge behavior, charge depth, coulombic efficiency, voltage energy efficiency cell polarization. IEC-optimized SFPAE with three different thicknesses (28 μm, 45 μm 80 μm) were prepared tested this study. It was found that combined effects ohmic loss electrolyte VRFB, governed by thickness, resulted an optimal under conditions tested. Thicker observed to cause higher while thinner yielded larger had negative impacts performance. The maximum power densities VRFBs assembled 28 μm, 80 μm 267 mW cm−2, 311 mW cm−2 253 mW cm−2 respectively, much than N212 membrane, 204 mW cm−2. results supported our previous observation superior regard data also indicated there is optimum a given set through can be significantly improved keeping constant.