【作者】 李刚；

【导师】 王瑞林；

【作者基本信息】 四川大学 ， 材料物理与化学， 2023， 硕士

【摘要】 全钒液流电池（VRFB）是一种可重复充放电的大规模储能系统,具备储能量大、安装灵活、施工周期短和寿命长等优点。在全钒液流电池中,隔膜是一个非常重要的组件。隔膜通过将正负极电解液隔开,但允许质子通行,以形成质子交换通路。然而,电池内部的膜材料会因长期使用而损耗,造成电池性能下降。因此,研究人员对膜材料的进行了研究,寻求提升电池性能的方法。磺化聚醚醚酮膜（SPEEK）因低成本、优异的热和电化学稳定性以及良好的机械性能等特点而备受关注。然而,当前SPEEK膜存在质子电导率和钒离子渗透率相互制约,其选择性不高的难点,亟需解决。本论文针对SPEEK膜选择性不高的问题,从侧链接枝、交联和复合三个角度系统地改性磺化聚醚醚酮基材,设计合成并制备了三种新型SPEEK改性膜,同时研究了他们的综合性能及其结构与性能之间的关系。本论文的主要研究内容如下:1、设计并合成了侧链接枝氨基磺酸（SA）的新型磺化聚醚醚酮（SPEEK-SA）材料,制备了一系列不同接枝度的SPEEK-SA材料和膜,并用所制备膜组装了单电池,探索了这些膜材料、膜和电池的物理化学性能。利用FT-IR和¹H NMR化学结构测试验证SA成功接枝SPEEK;与SPEEK基膜相比,所合成的SPEEK-SA系列膜的质子电导率、吸水率和溶胀度均有改善,其中SPEEK-SA-50膜的性能相对最佳。该膜的质子电导率达到0.099 S cm^-1,同时SPEEK-SA-50膜组装的VRFB在80 mA cm^-2电流密度下的库伦效率（CE）和能量效率（EE）分别为95.45%和76.11%。与使用Nafion 212膜和SPEEK基膜的电池相比,SPEEK-SA-50膜组装的单电池在同等测试条件下其EE分别高出9.06%和7.85%。2、以联苯胺双磺酸为交联剂,设计合成并制备了新型交联磺化聚醚醚酮（SPEEK-BDSA）材料和膜,并用所制备膜组装了单电池,研究了这些材料、膜和电池的物理化学性能。利用FT-IR和¹H NMR化学结构测试验证BDSA与SPEEK成功发生交联反应;相比SPEEK基膜,SPEEK-BDSA系列交联膜的质子电导率和阻钒渗透能力均有改善,其中SPEEK-BDSA-30膜的性能相对最佳,其质子电导率为0.088 S cm^-1。在60 mA cm^-2电流密度下,由SPEEK-BDSA-30膜组装的单电池表现出优异的性能,其库伦效率（CE）和能量效率（EE）分别为92.21%和79.12%。与使用Nafion 212膜和SPEEK基膜的电池相比,在相同的测试条件下,使用该膜的电池EE分别高出11.33%和8.58%。3、设计并合成了含氟的柔性聚磷腈衍生物聚[双（2-氟苯氧基）磷腈]（PFPP）材料,将其与SPEEK-BDSA复合制备共混复合膜（SP-B/PFPP）并用所制备膜组装了单电池,研究了材料、膜和电池的物理化学性能。FT-IR、¹H NMR和³¹P NMR结果表明PFPP材料和SP-B/X%PFPP膜成功制备。与SP-B基膜相比,SP-B/PFPP复合膜的吸水率和溶胀度以及钒离子渗透率均有改善。其中,SP-B/1%PFPP复合膜在综合性能方面表现出色,其钒离子渗透率为1.8×10^-6cm²min^-1。利用SP-B/1%PFPP复合膜组装的单电池,在100 mA cm^-2电流密度下,其库伦效率（CE）达到97.87%,能量效率（EE）为77.31%。在相同测试条件下,使用该复合膜的电池EE分别比使用SP-B膜（75.21%）与Nafion 212膜（76.16%）的电池明显提升。更多还原

【Abstract】 The Vanadium Redox Flow Battery（VRFB）is a large-scale energy storage system that possesses multiple advantages,including high energy storage capacity,flexible installation,short construction cycle,and long lifespan.It allows for repeatable charging and discharging and is considered a promising technology for large-scale energy storage.In a VRFB,the membrane is a critical component that separates the positive and negative electrolytes while simultaneously allowing proton exchange through the creation of a proton exchange pathway.However,prolonged use of the membrane material can cause degradation,leading to a decline in battery performance.Consequently,researchers have investigated various membrane materials to enhance battery performance.Sulfonated poly（etheretherketone）（SPEEK）membranes have garnered significant attention due to their low cost,excellent thermal and electrochemical stability,and good mechanical properties.Nevertheless,current SPEEK membranes exhibit low selectivity due to the mutual restriction between proton conductivity and vanadium ion permeability,necessitating urgent solutions.This study addresses the low selectivity issue of SPEEK membranes by systematically modifying the sulfonated poly（etheretherketone）substrate from three perspectives:side chain branching,crosslinking,and composite preparation.Three novel SPEEK-modified membranes were designed and prepared,and their comprehensive performance and the relationship between their structure and performance were analyzed.The main contents of this thesis are as follows:1.A new sulfonated poly（etheretherketone）material modified with side chain-branched amino sulfonic acid（SPEEK-SA）was designed and synthesized.A series of SPEEK-SA materials and membranes with varying degrees of grafting were prepared and assembled into single batterys to explore their physicochemical properties.The chemical structure was confirmed by FT-IR and ¹H NMR tests,indicating successful grafting of SA onto SPEEK.Compared to SPEEK-based membranes,the SPEEK-SA series showed improved proton conductivity,water uptake,and swelling ratio,with SPEEK-SA-50 membrane exhibiting the best performance.The proton conductivity of this membrane reached 0.099 S cm^-1,and the Coulombic efficiency（CE）and energy efficiency（EE）of the VRFB assembled with the SPEEK-SA-50 membrane at a current density of 80 mA cm^-2were 95.45%and 76.11%,respectively.Compared to batterys using Nafion 212 and SPEEK membranes,the single battery assembled with the SPEEK-SA-50 membrane exhibited an EE that was 9.06%and 7.85%higher,respectively,under the same test conditions.2.A novel crosslinked sulfonated poly（etheretherketone）material（SPEEK-BDSA）was designed and synthesized using biphenyl disulfonic acid as the crosslinking agent,and membranes were prepared and assembled into single batterys to investigate their physicochemical properties.The successful crosslinking reaction between BDSA and SPEEK was confirmed by FT-IR and ¹H NMR tests.Compared to SPEEK-based membranes,the SPEEK-BDSA series exhibited improved proton conductivity and vanadium ion blocking ability.Among them,the SPEEK-BDSA-30membrane exhibited the optimal performance,with a proton conductivity of 0.088 S cm^-1.The single battery assembled with the SPEEK-BDSA-30 membrane showed excellent performance at a current density of 60 mA cm^-2,with Coulombic efficiency（CE）and energy efficiency（EE）of 92.21%and 79.12%,respectively.Compared to batterys using Nafion 212 and SPEEK membranes,the EE of the battery using the SPEEK-BDSA-30 membrane was higher by 11.33%and 8.58%,respectively,under the same test conditions.3.A fluorinated flexible polyphthalonitrile derivative,poly[bis（2-fluorophenoxy）phthalonitrile]（PFPP）,was designed and synthesized.A composite membrane was prepared by blending PFPP with the SPEEK-BDSA membrane（SP-B/PFPP）,and subsequently assembled into a single battery to investigate their physicochemical properties.FT-IR,¹H NMR,and ³¹P NMR results confirmed the successful preparation of the PFPP material and SP-B/X%PFPP membrane.Compared to SP-B-based membranes,the SP-B/PFPP composite membrane exhibited improved water uptake,swelling ratio,and vanadium ion permeability.Of them,the SP-B/1%PFPP composite membrane showed the best comprehensive performance,with a vanadium ion permeability of 1.8×10^-6cm²min^-1.The single battery assembled with the SP-B/1%PFPP composite membrane showed excellent performance at a current density of 100 mA cm^-2,with Coulombic efficiency（CE）of 97.87%and energy efficiency（EE）of 77.31%.The EE of the battery using the SP-B/PFPP composite membrane was significantly higher than those using SP-B membrane（75.21%）and Nafion 212 membrane（76.16%）under the same test conditions.更多还原