自交联型磺化聚醚醚酮质子交换膜的合成

以含3,3'-二烯丙基双酚 A 结构单元的聚醚醚酮为基膜材料, 通过自由基加成反应在取代基上引入磺酸基团, 合成侧链型磺化聚醚醚酮(SPEEK)质子交换膜. 用傅里叶变换红外(FTIR)光谱、 核磁共振氢谱(¹H NMR)、 热重分析(TG)和扫描电子显微镜(SEM)等方法对 SPEEK 的结构进行表征. 实验结果表明, 巯基丙磺酸被接枝在聚醚醚酮侧基上, SPEEK 膜具有明显的亲水疏水微相分离形貌, 磺酸基团相互聚集形成离子通道. SPEEK 膜离子交换容量为 2.12 mmol/g, 钒离子渗透率为 1.54×10^-6 cm²/min, 低于Nafion117 膜的钒离子渗透率, 阻钒能力优于 Nafion117 膜. 以 SPEEK-4 膜组装电池的自放电时间约为130 h, 长于 Nafion117 膜的 66 h. 电池充放电循环 50 次, SPEEK-4 膜的库仑效率、 电压效率和能量效率没有明显降低, 显示出良好的稳定性.

Preparation and Performance of the Self-crosslinking Sulfonated Poly(ether ether ketone) Proton Exchange Membrane†

Side chain type, sulfonated poly(ether ether ketone)(SPEEK) was prepared via free radical addition reaction using PEEK containning 3,3'-diallyl bisphenol A structural unit and 3-mercaptopropane-sulphonate. The structure and morphology of SPEEK membrane were characterized by Fourier transform infrared spectroscopy(FTIR), ¹H NMR, TGA and SEM. The SPEEK has high hydrophilic/hydrophobic phase separation. Water uptake, mechanical property, proton conductivity, VO²⁺ permeability and single cell performances were investigated in order to understand the relationship between morphology and property of the membranes. The vanadium ion VO²⁺ permeability through the SPFEK-4 membrane(IEC=2.12 mmol/g) is 1.54×10^-6 cm²/min, which is lower than that of Nafion membrane(6.04×10^-6 cm²/min). Tests of SPPEK-4 in vanadium redox batteries(VRB) demonstrate a comparable Columbic efficiency(CE) and energy efficiency(EE) to that of Nafion117 at 50 mA/cm², and the SPPEK-4 membrane exhibits stable performance in cell over 50 charge-discharge cycles.