Mechanically durable and highly proton-conductive proton exchange membrane (PEM) is a crucial component for PEM fuel cell (PEMFC). Herein, we report a facile method to fabricate poly(tetrafluoroethylene) (PTFE)-reinforced composite membrane based on sulfonated poly(fluorenyl biphenyl) indole ionomer (PTFE-SPFBI). The resultant reinforced membrane exhibits an ultra-thin and dense structure, leading to a reduced swelling ratio, exceptional mechanical durability (with over 200 % elongation at break), and high chemical stability, primarily attributed to the presence of PTFE support. The ultra-thin nature of the PTFE-SPFBI membrane, coupled with its superior proton conductivity, significantly contributes to its performance in fuel cells, achieving a maximum power density of 778 mW cm⁻². Notably, this reinforced membrane exhibits remarkable endurance in open-circuit voltage (OCV) test, demonstrating its ability to sustain operation for more than 500 h at 90 °C and 30 % relative humidity. Overall, our work introduces a straightforward and promising approach for the fabrication of high-performance pore-filling PEMs using hydrocarbon ionomers, emphasizing enhanced durability and proton conductivity.

机械耐用且高质子传导性的质子交换膜 (PEM) 是质子交换膜燃料电池 (PEMFC) 的关键组件。在此，我们报告了一种基于磺化聚（芴基联苯）吲哚离聚物（PTFE-SPFBI）制造聚四氟乙烯（PTFE）增强复合膜的简便方法。所得的增强膜具有超薄而致密的结构，从而降低了溶胀率，具有出色的机械耐久性（断裂伸长率超过 200%）和高化学稳定性，这主要归功于 PTFE 支撑的存在。PTFE-SPFBI膜的超薄特性，加上其卓越的质子传导性，极大地提高了其在燃料电池中的性能，实现了778 mW cm ^-2的最大功率密度。值得注意的是，这种增强膜在开路电压（OCV）测试中表现出卓越的耐久性，证明其能够在 90°C 和 30% 相对湿度下维持运行超过 500 小时。总的来说，我们的工作介绍了一种简单且有前途的方法，用于使用碳氢化合物离聚物制造高性能孔隙填充质子交换膜，强调增强的耐用性和质子传导性。