全钒液流电池用SPEEK/PES共混膜的制备

Preparation of SPEEK/PES Blend Membranes for Vanadium Redox Flow Battery

通过将PES掺入高磺化度的SPEEK进行共混改性,采用流延法制备了一系列不同PES含量的SPEEK/PES共混膜,获得了SPEEK/PES共混膜的离子交换容、含水率、质子电导率等参数,特别测定了在全钒液流电池工作条件下钒(Ⅳ)离子渗透率。综合考察发现,当磺化温度为45℃,磺化时间控制为4 h,得到SPEEK的DS为55%,掺入10%的PES,此时共混膜的电导率为0.08 S/cm,钒(Ⅳ)离子渗透率为0.38×10-6cm2/min,对钒(Ⅳ)离子选择性为Nafion膜的5倍,含水率为35%,共混膜综合性能最好,基本满足全钒液流电池(VRB)的使用需求。

A series of SPEEK/PES blend membrane with different PES content were prepared by blending modification of SPEEK and PES with the casting method and characterized by many methods. These key parameters were firstly obtained and reported, such as the ion exchange capacity （ IEC）, water uptake, proton conductivity of the membranes and vanadium （IV） ion permeability in SPEEK membranes with different degrees of sulfonation （DS）. The best result was obtained when the sulfonation temperature was 45 %, the sulfonation time was 4h, the DS of SPEEK was 55%, and the content of PES was 10%. Among the membrane, the proton conductivity was 0. 08 S/cm, vanadium （IV） ion permeability was 0.38 10^ -6 cm2/min, the selectivity of the membrane was 5 times of Nation, and the water uptake was 35%. SPEEK/ PES blend membrane can basically meet the vanadium redox flow battery （VRB） demands in combination property.