Interfacially Assembled\nAnion Exchange Membranes for\nWater Electrolysis

High-performance and durable anion exchange membranes\n(AEMs) are\ncritical for realizing economical green hydrogen production through\nalkaline water electrolysis (AWE) or AEM water electrosysis (AEMWE).\nHowever, existing AEMs require sophisticated fabrication protocols\nand exhibit unsatisfactory electrochemical performance and long-term\ndurability. Here we report an AEM fabricated via a one-pot, in situ\ninterfacial Menshutkin reaction, which assembles a highly cross-linked\npolymer containing high-density quaternary ammoniums and nanovoids\ninside a reinforcing porous support. This structure endows the membrane\nwith high anion-conducting ability, water uptake (but low swelling),\nand mechanical and thermochemical robustness. Consequently, the assembled\nmembrane achieves excellent AWE (0.97 A cm<sup>–2</sup> at\n1.8 V) and AEMWE (5.23 A cm<sup>–2</sup> at 1.8 V) performance\nat 5 wt % KOH and 80 °C, significantly exceeding that of commercial\nand previously developed membranes, and excellent long-term durability.\nOur approach provides an effective method for fabricating AEMs for\nvarious energy and environmental applications.