A Porous Skeleton-Supported Organic/Inorganic Composite Membrane for High-Efficiency Alkaline Water Electrolysis

Hydrogen energy is a truly renewable and clean energy source. Alkaline water electrolysis (AWE) is the most promising technology for green hydrogen production currently. In the AWE process, the critical part of an alkaline electrolyzer is the membrane, which acts to conduct hydroxide ions and block gases. However, developing low area resistance, high bubble point pressure and highly stable membrane for high-performance AWE is still a challenge. Herein, porous skeleton-supported composite membranes via the blade-coating method for advanced AWE are prepared. The porous composite membranes, besides having hydrophilic surface, also show ultra-low area resistance (≈0.15 Ω cm²), ultra-high bubble point pressure (≈27 bar) and excellent mechanical properties (tensile stress, ≈14 MPa). By using commercial catalysts, the composite membranes exhibit a current density of up to 1.9 A cm⁻² at the voltage of 2 V in 30 wt% KOH solution at 80 °C and achieve ultra-high H₂ purity (up to 99.996%) when applied in AWE. Notably, the composite membrane can operate for more than 1600 h without performance attenuation, demonstrating excellent stability. This study opens up the feasibility of preparing high-performance AWE membranes for large-scale hydrogen production.