Porous Transport Layers for Proton Exchange Membrane Electrolysis Under Extreme Conditions of Current Density, Temperature, and Pressure

Hydrogen produced via water electrolysis powered by renewable electricity or green H 2 offers new decarbonization pathways. Proton exchange membrane water electrolysis (PEMWE) is a promising technology although the current density, temperature, and H 2 pressure of the PEMWE will have to be increased substantially to curtail the cost of green H 2 . Here, a porous transport layer for PEMWE is reported, that enables operation at up to 6 A cm −2 , 90  ° C, and 90 bar H 2 output pressure. It consists of a Ti porous sintered layer (PSL) on a low‐cost Ti mesh (PSL/mesh‐PTL) by diffusion bonding. This novel approach does not require a flow field in the bipolar plate. When using the mesh‐PTL without PSL, the cell potential increases significantly due to mass transport losses reaching ca. 2.5 V at 2 A cm −2 and 90  ° C. On the other hand, the PEMWE with the PSL/mesh‐PTL has the same cell potential but at 6 A cm −2 , thus increasing substantially the operation range of the electrolyzer. Extensive physical characterization and pore network simulation demonstrate that the PSL/mesh‐PTL leads to efficient gas/water management in the PEMWE. Finally, the PSL/mesh‐PTL is validated in an industrial size PEMWE in a container operating at 90 bar H 2 output pressure.