State-of-the-art high-temperature polymer electrolyte membrane fuel cells enabled by the phosphoric acid-doped polybenzimidazole material platform are promising for long-haul transport, but suffer from low output power, low Pt utilization, and rapid phosphoric acid loss under harsh/dynamic operating conditions. Here, we report a multifunctional phosphonated ionomeric binder (PFPA-PIM-SBI), derived from polymers of intrinsic microporosity, that addresses the above issues. Covalently bonded pentafluorophenyl phosphonic acid groups enhance proton conductivity, and the highly contorted molecular configuration of PFPA-PIM-SBI could prevent the undesirable adsorption of phenyl groups on the Pt catalyst, while frustrated polymer chain packing affords high microporosity for fast mass transport of gases and products. They combine to contribute to high-performing H₂/O₂ fuel cells, with a high Pt utilization of around 50%, a peak power density of >1000 mW cm⁻² at 240 °C and a high Pt mass-specific peak power density of 6.4 W mg_Pt⁻¹ at an ultralow Pt loading of 0.07 mg cm⁻². We disclose that the atypical phosphoric acid wettability of PFPA-PIM-SBI can prevent the migration of phosphoric acids to the electrode and the subsequent loss, accompanied by the inhibition of anhydride formation, enabling long-lifetime fuel cells at ultralow Pt loadings or under accelerated stress tests.

中文翻译：

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用于高功率、低铂负载和耐用高温燃料电池的电极粘合剂设计

由磷酸掺杂聚苯并咪唑材料平台实现的最先进的高温聚合物电解质膜燃料电池有望用于长途运输，但在运输过程中存在输出功率低、Pt利用率低以及磷酸快速损失的问题。恶劣/动态的操作条件。在这里，我们报告了一种多功能磷酸化离聚物粘合剂（PFPA-PIM-SBI），它源自固有微孔聚合物，可以解决上述问题。共价键合的五氟苯基膦酸基团增强了质子传导性，PFPA-PIM-SBI 的高度扭曲的分子构型可以防止苯基在 Pt 催化剂上的不良吸附，而受阻的聚合物链堆积提供了高微孔率，可实现气体和气体的快速传质。产品。它们共同构成了高性能 H ₂ /O ₂燃料电池，具有约 50% 的高 Pt 利用率、240 °C 时 >1000 mW cm ^-2的峰值功率密度以及高 Pt 质量比峰值功率在 0.07 mg cm ^-2的超低 Pt 负载量下，密度为 6.4 W mg _Pt ^-1。我们发现，PFPA-PIM-SBI 的非典型磷酸润湿性可以防止磷酸迁移到电极和随后的损失，同时抑制酸酐的形成，从而使燃料电池在超低 Pt 负载或加速条件下具有长寿命压力测试。