Optimization of the pendant chain length in partially fluorinated aromatic anion exchange membranes for alkaline fuel cells
Optimization of the pendant chain length in partially fluorinated aromatic anion exchange membranes for alkaline fuel cells
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DOI：
10.1039/c8ta04310h
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发表时间：
2018-08-07
影响因子：
11.9
通讯作者：
Miyatake, Kenji
中科院分区：
文献类型：
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作者：
Mahmoud, Ahmed Mohamed Ahmed;Miyatake, Kenji
为了获得稳定的阴离子交换膜，我们研究了脂肪族侧链对含铵基团的部分氟化芳香族共聚物（QPAF）性能的影响。成功地合成了一系列具有不同间隙脂肪族侧链长度（x = 2-6）的新型QPAF膜（QPAF-Cx）。具有丙烯侧链和离子交换容量（IEC = 1.24 meq.g（-1））的QPAF-C3显示出平衡的性质，具有最高的氢氧根离子电导率（在80 ℃下在水中为99 mS cm（-1））和相对低的吸水率，基于良好发展的相分离形态。此外，QPAF-C3膜表现出优异的碱性稳定性，以在80 ℃下在1 M KOH中1000 h后保持高离子电导率（98%剩余）和高机械性能。QPAF-C3膜甚至在4 M和8 M KOH中在80 ° C下也显示出合理的稳定性。在燃料电池操作中，QPAF-C3膜表现出比我们以前的QPAF-C1（138 mW cm（-2））、QPAF-C1 B（167 mW cm（-2））和Tokuyama A-201（122 mW cm（-2））膜更高的功率密度（224 mW cm（-2））。在62 h的耐久性测试中，QPAF-C3保持其初始电压的69%，具有轻微的结构退化。
For robust anion exchange membranes, we have investigated the effect of aliphatic side chains on the properties of partially fluorinated aromatic copolymers (QPAFs) with ammonium groups. A new series of QPAF membranes with various interstitial aliphatic side chain lengths (QPAF-Cx) where x = 2-6 were successfully synthesized. QPAF-C3 with a propylene side chain and ion exchange capacity (IEC = 1.24 meq.g(-1)) showed balanced properties with the highest hydroxide ion conductivity (99 mS cm(-1) at 80 degrees C in water) and relatively low water uptake, based on a well-developed phase separated morphology. Moreover, the QPAF-C3 membrane exhibited excellent alkaline stability to maintain high ion conductivity (98% remaining) and high mechanical properties after 1000 h in 1 M KOH at 80 degrees C. The QPAF-C3 membrane also revealed reasonable stability even in 4 M and 8 M KOH at 80 degrees C. In fuel cell operation, the QPAF-C3 membrane exhibited a higher power density (224 mW cm(-2)) than those of our previous QPAF-C1 (138 mW cm(-2)), QPAF-C1B (167 mW cm(-2)), and Tokuyama A-201 (122 mW cm(-2)) membranes. In the durability test for 62 h, QPAF-C3 maintained 69% of its initial voltage with minor structural degradation.