全钒液流电池用PVDF基离子交换膜

PVDF based ion exchange membrane for all vanadium redox flow battery

制备了3种聚偏氟乙烯(PVDF)基离子交换膜,比较了面电阻、离子交换容量(IEC)、含水率和钒离子渗透速率。PVDF与丙烯磺酸钠(SAS)共混制备的PVDF-SAS膜的面电阻最小,为1.2Ω.cm2,IEC达到1.16 mmol/g。FT-IR分析表明:这种膜在制备过程中,SAS的C C键在长时间高温后发生了聚合反应,与PVDF形成了互穿网络结构。自放电实验表明:所制备的膜在开路状态下,钒离子渗透速率小于8.8×10-3V/h。

Three kinds of polyvinylidene fluoride （PVDF） based ion exchange membranes were prepared, their area resistance,ion exchange capacity（IEC）, water content and vanadium ion permeability ratio were compared. The PVDF-sodium allylsulfonate （SAS） membrane prepared with a homogeneous solution of PVDF and SAS had the lowest area resistance of 1.2 Ω2-cm2,its IEC was 1.16 mmol/g. FT-IR analysis showed that the C =C bond of SAS polymerized after long time under high temperature and formed inter network structure with PVDF during the processes of the membranes formation. Self-discharge test showed that the vanadium ions permeation rate of the prepared membrane was below 8.8 x 10-3 V/h at open circuit condition.