Polymer electrolyte membrane (PEM) water electrolysis represents, in combination with renewable energy, progressive technology of hydrogen production. However, material-related issues still represent an obstacle in improvement of energy efficiency of the process. Porous transport layer (PTL) made usually of Ti, acting as a current collector and distributor of the water-gas flow, is a crucial part of the PEM water electrolysers. In this work, we investigate the impact of sintered Ti PTL structures on both the cathode and anode on the internal resistance of a single cell by means of voltage loss analysis. Less conventional and rarely applied porous transport electrode design favourable for high current density operation is used for the study. While activation and Ohmic resistance-related voltage losses were comparable for PTLs with different bulk porosities and pore opening diameters, mass transfer losses significantly increased when a less porous PTL was used on the anode. While the majority of mass transfer-related losses comes from the anode, it was proven that use of less porous cathode PTL mitigates these losses, pointing out a suitable combination of PTLs for improved performance.

聚合物电解质膜（PEM）水电解结合可再生能源，代表了制氢技术的进步。然而，与材料相关的问题仍然是提高工艺能效的障碍。通常由 Ti 制成的多孔传输层 (PTL) 作为水气流的集电器和分配器，是 PEM 水电解槽的关键部分。在这项工作中，我们通过电压损失分析研究了阴极和阳极上的烧结钛 PTL 结构对单电池内阻的影响。该研究使用了不那么传统且很少应用的多孔传输电极设计，有利于高电流密度操作。虽然活化和欧姆电阻相关的电压损失对于具有不同体积孔隙率和孔径的 PTL 是可比的，但当在阳极上使用较少孔隙的 PTL 时，传质损失显着增加。虽然大部分与传质相关的损失来自阳极，但事实证明，使用孔隙较少的阴极 PTL 可以减轻这些损失，指出 PTL 的合适组合可以提高性能。