全钒液流电池用非氟离子膜的制备与改性

发布时间：2018-04-19 19:50

本文选题：全钒液流电池 + 质子交换膜　；参考：《深圳大学》2015年硕士论文

【摘要】：在大力发展可再生能源的背景下,储能技术也在飞速发展。全钒液流电池作为一种具有潜力的储能系统,具有低成本、长寿命、可深度充放电和设计灵活等特点,在太阳能和风力发电的储能设备、后备电源、电网的削峰填谷等方面有望得到应用。作为全钒液流电池重要的部件之一,质子交换膜直接影响着电池的成本、性能和寿命。目前广泛使用的质子交换膜为全氟结构的Nafion膜,但由于其价格昂贵、钒离子渗透率高,制约了全钒液流电池的发展。因而寻找价格合适、离子选择性高且寿命较长的非氟离子膜就成为研究的热点。本论文以低成本的非氟型磺化聚芳醚酮和磺化聚醚醚酮为研究对象,进行合理设计或改性,制备出几种特别适用于全钒液流电池的高选择性离子膜,并提出了可能的作用机制。通过双酚芴、磺化二氟酮钠、二氟二苯砜和具有刚性苯环结构的B3单体的缩聚反应合成了支化度为8%的聚芳醚酮聚合物(HSPAEK)。HSPAEK具有良好的溶解性,HSPAEK膜透明、具有柔韧性。SEM和EDX图显示其表面和断面都是致密均匀的。HSPAEK膜具有低溶胀率、适中的吸水率和质子电导率。除此之外,HSPAEK膜还具有很低的VO~(2+)渗透率,因而具有较好的离子选择性和较长的自放电时间。装入全钒液流电池中,HSPAEK膜具有较高的库仑效率和容量保持率,说明HSPAEK膜具有较好的化学稳定性,因而在全钒液流电池中具有一定应用潜力。通过在SPEEK膜内掺杂三种纳米无机氧化物(Al_2O_3、SiO_2和TiO_2)制备了SPEEK基复合膜,考察了纳米无机氧化物的质量分数(2.5%、5%、7.5%、10%)对复合膜的结构与性能的影响。通过SEM观察发现,复合膜体相致密且掺杂物分布较为均匀。无机纳米氧化物(Al_2O_3、SiO_2和TiO_2)的质量掺杂比例为5%的三种膜(S/A-5%、S/S-5%、S/T-5%)性能最好。S/A-5%、S/S-5%、S/T-5%膜相比于纯SPEEK膜,具有更好的热稳定性、机械强度和化学稳定性。与Nafion 117和纯SPEEK膜相比,复合膜具有较低的VO~(2+)渗透率。由于S/A-5%、S/S-5%、S/T-5%具有较高的离子选择性(低VO~(2+)渗透率与适中的质子电导率),与Nafion117和纯SPEEK膜相比,复合膜具有较高的能量效率。在200圈的循环寿命测试后,S/A-5%的容量保持率为53.3%,S/S-5%为50.8%,S/T-5%为39.5%,都高于Nafion 117的24.7%,显示出复合膜的较高稳定性。通过聚多巴胺(PDA)对纳米SiO_2进行表面包覆修饰,得到了表面带氨基的SiO_2纳米粒子,通过TEM观察发现PDA-SiO_2表面可以看到一层2-3 nm的包覆层。PDA-SiO_2作为填料掺入SPEEK膜中,复合膜的能量效率较SPEEK膜有所提高,但寿命相比于S/S-5%复合膜反而降低了。
[Abstract]:In the context of the development of renewable energy, energy storage technology is also developing rapidly. As a potential energy storage system, all vanadium liquid flow battery has the characteristics of low cost, long life, deep charge and discharge, flexible design, etc., in solar and wind energy storage equipment, backup power, It is expected that the peak cutting and valley filling of power grid will be applied. As one of the important components of vanadium liquid flow battery, proton exchange membrane directly affects the cost, performance and lifetime of the battery. The widely used proton exchange membrane is Nafion membrane with perfluorine structure, but the development of vanadium liquid flow battery is restricted because of its high price and high vanadium ion permeability. Therefore, it has become a hot topic to find non-fluorine ion membranes with high ion selectivity and long lifetime. In this paper, the low cost non fluorinated sulfonated poly (aryl ether ketone) and sulfonated polyether ether ketone (sulfonated polyether ether ketone) were studied, and several kinds of high selective ion membranes were prepared, which are especially suitable for all vanadium liquid flow batteries, and the possible mechanism was put forward. Through the condensation reaction of bisphenol fluorene, sodium difluorone sulfonate, difluorodiphenyl sulfone and B _ 3 monomer with rigid benzene ring structure, the branched polyaryl ether ketone polymer (HSPAEK). HSPAEK has good solubility and transparency. Its surface and section are compact and uniform. HSPAEK film has low swelling rate, moderate water absorption and proton conductivity. In addition, HSPAEK film also has low VO~(2) permeability, so it has better ion selectivity and longer self-discharge time. HSPAEK film has high Coulomb efficiency and capacity retention in vanadium liquid flow battery, which indicates that HSPAEK film has good chemical stability, so it has certain application potential in all vanadium liquid flow battery. SPEEK based composite membranes were prepared by doping Al2O3SiO2 and TiO2 into SPEEK films. The effect of the mass fraction of nano-inorganic oxides on the structure and properties of the composite membranes was investigated. The results of SEM show that the composite films are compact and the dopants are uniformly distributed. The three kinds of films with a mass doping ratio of 5% to 5% of the inorganic nano-oxide Al2O3SiO _ 2 have a better thermal stability, mechanical strength, and chemical stability than the pure SPEEK films. Compared with Nafion 117 and pure SPEEK membranes, the composite membranes have lower VO~(2) permeability. Because of the high ion selectivity (low VO~(2) permeability and moderate proton conductivity, the composite membranes have higher energy efficiency than Nafion117 and pure SPEEK membranes. After 200 cycles of cycle life test, the capacity retention rate of S- / A-5% is 53.3%, and the S- / S-5% is 50.8% and ST-5% is 39.5%, which is higher than that of Nafion 117 (24.7%), which shows the high stability of the composite membrane. SiO_2 nanoparticles with amino groups on the surface of SiO_2 were prepared by surface coating of PDAs. By TEM observation, a 2-3 nm coating layer. PDA-SiO2 was found to be doped into the SPEEK film. The energy efficiency of the composite membrane is higher than that of the SPEEK membrane, but the lifetime of the composite membrane is lower than that of the S / S-5% composite membrane.
【学位授予单位】：深圳大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TM912;TQ425.236

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