Abstract In this study, a super acid with impressive hygroscopicity, 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethanesulfonyl)imide (MPTI), is exploited to improve the proton conductivity of PEMs at low humidity. Importantly, MPTI can deliquesce into an aqueous solution by capturing moisture from air at a considerable rate. Investigation of the hygroscopicity of MPTI and the corresponding mechanism by molecular dynamics simulation show a total interaction energy between MPTI and water of −368.13 kJ mol−1, which greatly exceeds those of model derivatives with other typical hygroscopic groups. To apply MPTI in PEMs and prevent leakage, MPTI is incorporated into a semi-interpenetrating polymer network via in situ polymerization, and Nafion-based composite membranes are fabricated. The water uptake of the obtained hybrid membranes is substantially increased by up to 66.61% at 40% RH and 90.04% at 95% RH. This optimization of the water environment facilitates the dissociation of protons and the formation of hydrogen bond networks for high-speed proton conduction. As a result, the proton conductivity of the membranes increases by up to two orders of magnitude at low humidity. Notably, this composite membrane enhanced the performance of a single fuel cell at 60% RH by 41.9%.

中文翻译：

---

基于三氟甲磺酰亚胺的吸湿性半互穿聚合物网络在低湿度下增强基于全氟磺酸的质子交换膜的质子传导性

摘要 在这项研究中，一种具有显着吸湿性的超强酸 1-[3-(甲基丙烯酰氧基)丙基磺酰基]-1-(三氟甲磺酰基)亚胺 (MPTI) 被用于提高低湿度下 PEM 的质子传导性。重要的是，MPTI 可以通过以相当大的速度从空气中捕获水分而潮解成水溶液。通过分子动力学模拟研究 MPTI 的吸湿性和相应机制，表明 MPTI 与水之间的总相互作用能为 -368.13 kJ mol-1，大大超过了具有其他典型吸湿基团的模型衍生物。为了在 PEM 中应用 MPTI 并防止泄漏，通过原位聚合将 MPTI 结合到半互穿聚合物网络中，并制造了基于 Nafion 的复合膜。所得混合膜的吸水率在 40% RH 和 95% RH 下显着增加了 66.61% 和 90.04%。这种水环境的优化促进了质子的解离和高速质子传导的氢键网络的形成。结果，在低湿度下，膜的质子传导率增加了两个数量级。值得注意的是，这种复合膜将单个燃料电池在 60% RH 下的性能提高了 41.9%。