高性能PVDF/SiO_2@HPA复合膜在全钒液流电池中的应用

The high Performance PVDF/SiO_2@HPA Composite Membrane for All Vanadium Redox Flow Battery Application

以聚偏氟乙烯(PVDF)多孔膜为基质,采用原位凝胶溶胶合成二氧化硅负载磷钨酸(Si O2@HPA)纳米粒子的方法对多孔膜进行修饰。分别用扫描电子显微镜、电化学工作站、充放电测试仪等仪器对膜的结构、电化学性能进行表征。结果表明:与空白的PVDF相比,经过纳米粒子修饰的复合膜的钒离子选择性得到明显提高。在不同的电流密度下,修饰后的复合膜的充放电效率都高于未修饰PVDF多孔膜,并且在40m A·cm-2的电流密度下,复合膜的能量效率提高了17.6%。在80 m A·cm-2的电流密度下,用PVDF/Si O2@HPA组装的电池在100圈的循环测试中保持较好的稳定性。

Polyvinylidene fluoride （PVDF） porous membrane was prepared by immersion phase inversion method and filled with SiO2@ phosphotungstic acid （HPA） nanoparticles synthesized by in-situ gel sol methods. The structure and electrochemical properties of the membranes were characterized by scanning electron microscope, electrochemical workstation, charge and discharge device, etc. The results show that, compared with the pristine PVDF membrane, the vanadium ion selectivity of the porous membranes modified by nanoparticles are obviously improved. In addition, the charge-discharge efficiency of PVDF/SiO2@HPA composite membranes is superior to the pristine PVDF porous membrane under the different current density and its energy efficiency （EE=77.8 %） increase by 17.6 % compared with the pristine PVDF porous membrane （EE=66.1%）, Meanwhile, the PVDF/SiO2@HPA composite membranes exhibited a good stability in the 100 circle cycle.