通过溶液流延成膜法制备了具有不同离子交换容量(IEC)的全氟磺酸(PFSA)离子交换膜,并测试了其吸水率、电导率、钒离子(Ⅴ(Ⅳ))透过率和选择性系数。研究发现,具有高IEC值的PFSA离子交换膜具有相对较低的Ⅴ(Ⅳ)离子透过率和较高的质子电导率。其中IEC值为1.10mmol/g的PFSA离子交换膜对Ⅴ(Ⅳ)离子具有最高的选择性,其选择性系数为Nafion 117膜的2.97倍。
Perfluorosulfonated acid (PFSA) ion exchange membranes, with different ion exchange capacities (IECs), were prepared by a solution-casting method for vanadium redox flow battery applications. Water uptake, proton conductivity, vanadium ion permeability and selectivity of the PFSA ion exchange membranes were investigated. It is found that membranes with higher IEC values have relatively lower vanadium ion permeability and higher proton conductivity. The highest selectivity of the membranes being characterized was achieved from the PFSA ion exchange membrane with 1.10 mmol/g, which was 2.97 times higher than that of Nafion 117 membrane.