On the influence of porous transport layers parameters on the performances of polymer electrolyte membrane water electrolysis cells

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.