One promising approach to reduce the cost of fuel cell systems is to develop hydroxide exchange membrane fuel cells (HEMFCs), which open up the possibility of platinum-group-metal-free catalysts and low-cost bipolar plates. However, scalable alkaline polyelectrolytes (hydroxide exchange membranes and hydroxide exchange ionomers), a key component of HEMFCs, with desired properties are currently unavailable, which presents a major barrier to the development of HEMFCs. Here we show hydroxide exchange membranes and hydroxide exchange ionomers based on poly(aryl piperidinium) (PAP) that simultaneously possess adequate ionic conductivity, chemical stability, mechanical robustness, gas separation and selective solubility. These properties originate from the combination of the piperidinium cation and the rigid ether-bond-free aryl backbone. A low-Pt membrane electrode assembly with a Ag-based cathode using PAP materials showed an excellent peak power density of 920 mW cm⁻² and operated stably at a constant current density of 500 mA cm⁻² for 300 h with H₂/CO₂-free air at 95 °C.

降低燃料电池系统成本的一种有前途的方法是开发氢氧化物交换膜燃料电池（HEMFC），这开辟了不含铂族金属的催化剂和低成本双极板的可能性。但是，目前尚无法获得具有所需性能的可伸缩的碱性聚电解质（氢氧化物交换膜和氢氧化物交换离聚物），这是HEMFC的关键组成部分，这对HEMFC的开发构成了主要障碍。在这里，我们显示了基于聚（芳基哌啶）（PAP）的氢氧化物交换膜和氢氧化物交换离聚物，它们同时具有足够的离子电导率，化学稳定性，机械强度，气体分离和选择性溶解度。这些性质源自哌啶阳离子和刚性无醚键芳基骨架的组合。^-2，并在95°C下使用不含H ₂ / CO _2的空气在500 mA cm ^-2的恒定电流密度下稳定运行300 h 。