质子交换膜对钒氧化还原液流电池性能的影响

采用溶液接枝聚合法制备了一种新型的质子交换膜PVDF-g-PSSA, 测定了PVDF-g-PSSA膜、Nafion 117 膜和PE01均相膜的离子交换能力和电导率, 并分别研究了以这3种膜为隔膜的钒电池的电化学性能. 实验结果表明, PVDF-g-PSSA膜具有优良的质子电导率和离子交换能力, 室温下其离子交换能力和质子电导率分别为1.13 mmol/g和3.22×10-2 S/cm, 在不同的充放电电流密度下, 以PVDF-g-PSSA膜为隔膜的钒电池的库仑效率和能量效率明显高于Nafion 117膜和PE01均相膜为隔膜的钒电池; PVDF-g-PSSA膜阻钒离子的渗透性能与PE01均相膜基本一致, 都明显优于Nafion 117膜的阻钒离子渗透能力.

Effects of Proton Exchange Membranes on Performance of Vanadium Redox Flow Battery

The poly(vinylidene fluoride)-graft-poly(styrene sulfonic acid) (PVDF-g-PSSA) membrane was prepared by a solution-grafting method for vanadium redox flow battery (VRB)as the separator. The ion exchange capacity (IEC), conductivity of PVDF-g-PSSA, Nafion 117 and PE01 homogeneous membranes were investigated contrastively. The electrochemical performance of VRB with PVDF-g-PSSA, Nafion 117 and PE01 homogeneous membranes as the separator, respectively, was studied. The results show that PVDF-g-PSSA membrane possessed a high conductivity and excellent IEC with a value 3.22×10-2 S/cm and 1.13 mmol/g respectively, at room temperature. PVDF-g-PSSA membrane showed dramatically lower vanadium ion permeability compared to Nafion 117, its coulombic efficiency and energy efficiency of VRB with PVDF-g-PSSA as the separator being higher notablely than that of VRB with Nafion 117 and PE01 homogeneous membranes as the separator.