全钒液流电池用杂环聚芳醚的设计及其两性膜的结构与性能关系研究

All-vanadium redox flow battery (VRB) is a kind of high efficient energy storage equipment. The ion exchange membrane is one of key components of VRB batteries, whose properties determine the use life and energy efficiency of VRB to some degree. Nowadays, the membrane materials for VRB applications are insufficient, and single anion exchange membrane or cation exchange membrane can not entirely meet the requirements of VRB applications, which limit the commercial applications of VRB. Based on the design of molecular structure, poly(phthalazinone ether)s containing methyl moieties membrane materials will be synthesized. The bromination of methyl groups will be studied to prepare poly(phthalazinone ether)s containing bromomethyl moieties. Blend baes membranes will be prepared from poly(phthalazinone ether)s containing bromomethyl moieties and sulfonated poly(phthalazinone ether)s by casting solution, then the base membranes will be quaternized and acidized successively to obtain poly(phthalazinone ether)s amphoteric ion exchange membranes containing both quaternary ammonium groups and sulfuric acid groups. The control mechanism of poly(phthalazinone ether)s amphoteric ion exchange membranes microstructure will be studied. The relationship between main chain structure of membrane material, kinds and content of ion groups, morphology of ion exchange membranes and properties of amphoteric ion exchange membranes will be investigated. The relationship between structure of membrane material, morphology of amphoteric ion exchange membranes and VRB single cell properties of membranes will be understood, which has very important theoretical and practical application value on the design and preparation of novel ion exchange membranes for VRB applications with high selectivity, high conductivity and high chemical stability.

全钒液流电池是一种高效电能储存装置。离子交换膜是全钒液流电池的关键部件之一，其性能决定了全钒液流电池的使用寿命和能量效率。目前，全钒液流电池用膜材料仍较少，而且单一的阳离子交换膜或阴离子交换膜较难完全满足其使用需求，限制了全钒液流电池的商业化推广应用。本项目从分子结构设计出发，合成系列含甲基杂萘联苯共聚芳醚，研究其甲基单溴化反应，制备含溴甲基杂萘联苯共聚芳醚；以含溴甲基杂萘联苯共聚芳醚和磺化杂萘联苯聚芳醚为膜材料，采用溶液法制备共混基膜，经季铵化、酸化，制备既含有季铵基团又含有磺酸基团的杂环聚芳醚两性离子交换膜。研究杂环聚芳醚两性膜微观结构的调控机制；研究膜材料主链结构和离子基团的种类、数量以及膜的微观结构等与两性膜性能的关系；揭示膜材料结构、两性膜微观结构与全钒液流电池性能的关系，对新型高选择性、高离子传导率、高稳定性全钒液流电池用离子交换膜的设计及制备具有重要的理论意义和实际应用价值。

本项目从分子结构设计出发，合成了系列含甲基杂萘联苯共聚芳醚，研究其甲基单溴化反应，优化工艺条件，制备了含溴甲基杂萘联苯共聚芳醚，通过调节含甲基杂萘联苯共聚芳醚的甲基含量实现了含溴甲基杂萘联苯聚芳醚溴甲基含量的控制；以含溴甲基杂萘联苯共聚芳醚和磺化杂萘联苯聚芳醚为膜材料，采用溶液法制备了杂萘联苯聚芳醚共混基膜，对基膜的结构进行了表征，EDX能谱表明基膜中S和Br元素分布均匀，说明含溴甲基杂萘联苯共聚芳醚和磺化杂萘联苯聚芳醚具有较好的相容性。经过对基膜进行季铵化、酸化处理，制备了既含有季铵基团又含有磺酸基团的杂萘联苯聚芳醚两性离子交换膜。考察了含溴甲基杂萘联苯共聚芳醚与磺化杂萘联苯聚芳醚共混比例、基团含量、溶剂蒸发温度、溶剂蒸发时间、季铵化反应温度等对两性离子交换膜结构和性能的影响。研究了杂萘联苯聚芳醚两性膜微观结构的调控机制；研究了膜材料链结构和离子基团的种类、数量以及膜的微观结构等与两性膜性能的关系；考察了含溴甲基杂萘联苯共聚芳醚与磺化杂萘联苯聚芳醚共混比例、基团含量、制膜工艺条件等对所组装钒电池单电池性能的影响，揭示了膜材料结构、两性膜微观结构与全钒液流电池性能的关系。随着含溴甲基杂萘联苯共聚芳醚中溴甲基含量增加或磺化杂萘联苯聚芳醚的磺酸基含量增加，两性离子交换膜的面电阻降低，离子传导性提高，但是稳定性略有下降。杂萘联苯聚芳醚两性离子交换膜组装钒电池的库伦效率高于Nafion115膜，能量效率可以达到90.6%，水迁移远低于Nafion115膜，表现出较好的稳定性和电池性能。杂萘联苯聚芳醚两性离子交换膜在一定程度上改善了单一型离子交换膜的性能，对新型高选择性、高离子传导率、高稳定性全钒液流电池用离子交换膜的设计及制备具有重要的理论意义。