Electrostatic Self-Adsorption Stabilized Ultra-Thin Composite Membrane Enabling High-Performance Alkaline Water Electrolysis

Developing high-performance, ultra-thin membranes for alkaline water electrolysis (AWE) remains challenging due to organic-inorganic phase separation under harsh conditions. Here, an ultrathin (≈120 µm) polyether sulfone/zirconia (PES/ZrO 2 ) composite membrane is designed via interfacial engineering using a titanate coupling agent (CHOPT). The modified ZrO 2 exhibits opposite Zeta potential to PES, enabling electrostatic self-adsorption that strengthens with alkalinity, ensuring durable nanoparticle anchoring. Incorporating a PPS mesh further enhances mechanical stability. The optimized membrane achieves exceptional performance: ultra-low area resistance (0.09 Ω cm 2 ), high bubble point pressure (4.55 bar), and excellent hydrophilicity. In 30 wt% KOH at 80 °C, the membrane enables electrolyzer operation at 1.82–1.88 V (1.0 A cm −2 ) with 150-hour stability. Additionally, theoretical calculations and molecular dynamics simulations provide insights into the mechanisms behind the membrane's outstanding performance. This work provides a scalable strategy for durable, high-efficiency AWE membranes, addressing critical challenges in green hydrogen production.