全钒液流电池用磺化聚芴醚酮质子交换膜的制备及性能  

Preparation and properties of sulfonated poly(fluorenyl ether ketone) proton exchange membranes for vanadium redox flow battery

作　　者：叶洲麟 熊雷 林起浪[1] 陈栋阳[1] YE Zhoulin;XIONG Lei;LIN Qilang;CHEN Dongyang(School of Materials Science and Engineering,Fuzhou University,Fuzhou 350116,Fujian,China)

机构地区：[1]福州大学材料科学与工程学院,福建福州350116

出　　处：《精细化工》2024年第2期348-357,380,共11页Fine Chemicals

基　　金：国家自然科学基金项目(51873037);福建省自然科学基金项目(2020J01475)。

摘　　要：首先,将9,9-二(3,5-二甲基-4-羟基苯基)芴(DMBHF)、9,9-双(4-羟苯基)芴(BHF)和4,4’-二氟二苯甲酮(DFB)在高温下缩聚,得到聚芴醚酮(PFEK-x)(x=30、40、50,x为DMBHF含量,以DFB的物质的量计,下同);接着,利用溴代反应将PFEK-x的甲基功能化为溴甲基;然后,通过4-羟基苯磺酸钠的SN2亲核取代制得具有不同离子交换容量的磺化聚芴醚酮(SPFEK-x);最后,通过溶液浇铸法成膜并酸化,制得新型低成本质子交换膜(PEMs)。采用^(1)HNMR、FTIR、TGA对其进行了表征,并对其性能进行了测试。结果表明,SPFEK-40膜具有较高的质子传导率及离子选择性、较低的钒离子渗透率及面电阻,综合性能优异。以SPFEK-40膜组装的全钒液流电池(VRFB)在电流密度为80 m A/cm^(2)时的能量效率为88.2%,高于以Nafion 212膜组装的VRFB的84.8%。此外,以SPFEK-40膜组装的VRFB在30次循环后放电容量保持率为84.3%,远高于以Nafion 212膜组装的VRFB(66.1%)。该合成路线的原料来源广泛,价格低廉,不涉及危险的磺化反应,易于工业放大。制得的SPFEK-x均具有良好的机械性能和氧化稳定性。Poly(fluorenyl ether ketone)s(PFEK-x)were firstly synthesized from high-temperature polycondensation of 9,9-bis(3,5-dimethyl-4-hydroxyphenyl)fluorene(DMBHF),9,9-bis(4-hydroxyphenyl)fluorene(BHF)and 4,4'-difluorophenone(DFB),herein,x=30,40,50,and refers to the content of DMBHF(based on the amount of substance of DFB,the same below).The PFEK-x obtained were then brominated by bromination of the methyl groups and then reacted with sodium 4-hydroxybenzenesulfonate to yield sulfonated poly(fluorenyl ether ketone)s(SPFEK-x)with different ion exchange capacities.Finally,novel and low-cost proton exchange membranes(PEMs)were prepared by solution-casting SPFEK-x into membranes and acidification.The samples were characterized by ^(1)HNMR,FTIR and TGA,followed by analysis on their properties.The results showed that SPFEK-40 membrane exhibited excellent comprehensive performances,such as high proton conductivity and icon selectivity,low VO^(2+)permeability,and low surface resistance.The energy efficiency of vanadium redox flow battery(VRFB)assembled with SPFEK-40 membrane reached 88.2%at a current density of 80 mA/cm^(2),higher than that of the VRFB assembled with Nafion 212(84.8%).In addition,the discharge capacity retention ratio of the VRFB assembled with SPFEK-40 membrane after 30 cycles was 84.3%,which was much higher than that of the VRFB assembled with Nafion 212(66.1%).Moreover,the synthetic route could be scaled-up easily since it was based on inexpensive raw materials without dangerous sulfonation reactions. The SPFEK-x membranes also displayed good mechanical properties and oxidation stability.

关 键 词：全钒液流电池 质子交换膜 聚芴醚酮 质子传导率 能量效率 功能材料 

分 类 号：TM912[电气工程—电力电子与电力传动] TB383.2[一般工业技术—材料科学与工程]