Membrane Reinforcement Strategy Using Robust Nanofibers for Durable and Safe AEM Water Electrolysis

Anion exchange membrane (AEM) water electrolysis offers a sustainable route to green hydrogen but is limited by low ionic conductivity, excessive swelling, and mechanical instability under high-pressure conditions. Here, a reinforced composite membrane (RCM) comprising Fumion FAA-3 (FuMa-Tech) ionomer infiltrated into an electrospun polytetrafluoroethylene (PTFE) nanofiber (NF) network is reported. The porous PTFE NF scaffold enhances dimensional stability and structural integrity, mitigating swelling-induced degradation while preserving efficient hydroxide-ion transport. Embedded PTFE fibers also serve as physical barriers at the electrode interface, reducing gas crossover and minimizing short-circuit risk. The resulting PTFE/FAA RCM, with a thickness of ≈50 µm, exhibits an initial current density of 2.9 A cm^-2 at 2.0 V and maintains stable operation for over 1000 h under 1 m KOH at 70 °C. Mechanical testing confirms significant improvements in tensile strength and elongation at break compared to pure ionomer films. Electrochemical impedance spectroscopy demonstrates reduced charge transfer and ohmic resistances, correlating with enhanced ionic pathways and membrane robustness. These findings underscore the potential of NF-reinforced composite architectures to overcome key AEM limitations, enabling durable, high-performance water electrolysis systems and advancing the commercialization of cost-effective, safe hydrogen production.