Abstract Ionically crosslinked acid/base blend membranes of PBI-OO and a sulfonated polysulfone can be covalently crosslinked through aromatic sulfone groups, which form in a thermally induced Friedel-Crafts reaction. Here we systematically compare a series of blend membranes before and after curing. Even though the cured membranes have a lower phosphoric acid uptake even at increased doping time and temperature, they have an improved conductivity and therefore fuel cell performance than the ionically crosslinked membranes. For example, a covalently crosslinked blend membrane containing 5% of the acid component (c-BM 1) reached a conductivity of 260 mS/cm at 160 °C and a relative humidity of 5%, even though the PA uptake was just 266 wt%. In the fuel cell (H 2 , air, 160 °C), this membrane yielded a peak power density of 452 mW cm −2 , about 100 mW cm −2 above that of the commercial meta-PBI membrane. In a long term stability test, the ionically crosslinked membrane uc-BM 1 already failed within 100 h, while the cured c-BM 1 membrane was much more stable. A cured membrane with less PA and higher amount of the acid blend component (c-BM 3) gave a stable performance for over 1000 h, proving that thermally induced sulfone crosslinking strongly increases the stability.

中文翻译：

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用于高温聚合物电解质燃料电池的磷酸掺杂交联聚苯并咪唑（PBI-OO）共混膜

摘要 PBI-OO 和磺化聚砜的离子交联酸/碱混合膜可以通过芳族砜基团共价交联，芳族砜基团在热诱导的弗瑞德-克来福特反应中形成。在这里，我们系统地比较了一系列固化前后的混合膜。尽管固化膜即使在增加掺杂时间和温度下也具有较低的磷酸吸收，但与离子交联膜相比，它们具有改进的电导率并因此具有改进的燃料电池性能。例如，含有 5% 酸组分 (c-BM 1) 的共价交联混合膜在 160 °C 和 5% 的相对湿度下达到了 260 mS/cm 的电导率，即使 PA 吸收量仅为 266 wt% %。在燃料电池（H 2 ，空气，160 °C）中，该膜产生了 452 mW cm -2 的峰值功率密度，比商用meta-PBI膜高约100 mW cm -2 。在长期稳定性测试中，离子交联膜 uc-BM 1 已在 100 小时内失效，而固化的 c-BM 1 膜要稳定得多。具有较少 PA 和较高量酸共混组分 (c-BM 3) 的固化膜在超过 1000 小时内具有稳定的性能，证明热诱导的砜交联大大提高了稳定性。