Aliphatic/aromatic polyimide lonomers as a proton conductive membrane for fuel cell applications
Aliphatic/aromatic polyimide lonomers as a proton conductive membrane for fuel cell applications
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DOI：
10.1021/ja0571491
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发表时间：
2006-02-08
影响因子：
15
通讯作者：
Watanabe, M
中科院分区：
文献类型：
--
作者：
Asano, N;Aoki, M;Watanabe, M
为了生产一种用于燃料电池的质子导电和耐用的聚合物电解质膜，合成了一系列在主链和侧链上都含有脂肪基团的磺化聚酰亚胺离聚体。通过典型缩聚反应得到了离子交换容量为1.78 ~ 2.33 mequiv/g的聚酰亚胺离聚体1，其薄膜具有透明、延展性和柔韧性。在100℃以下，1的质子电导率略低于全氟化离聚体（Nafion），但在更高温度和100%相对湿度下相当。在140℃下，1的最高电导率为0.18 S cm(-1)，具有高IEC和支链化学结构的单体1在不牺牲膜稳定性的情况下表现出更好的质子导电行为。微观分析表明，更小（< 5 nm）和分散良好的亲水结构域有助于更好的质子导电性能。在干湿条件下，1的氢透性和氧透性都比Nafion低1-2个数量级。燃料电池由1层膜制成，在80℃和0.2 A/cm(2)的条件下工作，提供60%或90% RH的H-2和空气。lonomer 1膜表现出与Nafion相当的性能，并且在5000小时内没有明显的降解。
To produce a proton conductive and durable polymer electrolyte membrane for fuel cell applications, a series of sulfonated polyimide ionomers containing aliphatic groups both in the main and in the side chains have been synthesized. The title polyimide ionomers 1 with the ion exchange capacity of 1.78-2.33 mequiv/g were obtained by a typical polycondensation reaction as transparent, ductile, and flexible membranes. The proton conductivity of 1 was slightly lower than that of the perfluorinated ionomer (Nafion) below 100 degrees C, but comparable at higher temperature and 100% RH. The highest conductivity of 0.18 S cm(-1) was obtained for 1 at 140 degrees C. lonomer 1 with high IEC and branched chemical structure exhibited improved proton conducting behavior without sacrificing membrane stability. Microscopic analyses revealed that smaller (< 5 nm) and well-dispersed hydrophilic domains contribute to better proton conducting properties. Hydrogen and oxygen permeability of 1 was 1-2 orders of magnitude lower than that of Nafion under both dry and wet conditions. Fuel cell was fabricated with 1 membrane and operated at 80 degrees C and 0.2 A/cm(2) supplying H-2 and air both at 60% or 90% RH. lonomer 1 membrane showed comparable performance to Nafion and was durable for 5000 h without distinct degradation.