Characterisation of mass transport in mesh-type flow-field based polymer electrolyte membrane water electrolysers by neutron imaging

Journal article

Flow-fields are essential for effective mass transport in polymer electrolyte membrane water electrolysers (PEMWEs). However, conventional flow-fields often face challenges in achieving reactant homogeneity across the full area of the electrode. This study explores the mass transport characteristics of PEMWEs using a mesh-type flow-field, analysed through neutron imaging and electrochemical impedance spectroscopy. The mesh-type design demonstrates superior cell performance and lower mass transport resistance compared to the conventional parallel design under the conditions tested. Neutron imaging results show that the mesh-type flow-field achieves a more uniform water distribution across the active area, as indicated by significantly lower standard deviations in water thickness. In contrast, the parallel design experiences a more rapid decline in the fraction of water remaining in the flow-field area (indicating a significant build-up of gas bubbles and heterogeneity of available reactant water). This uniformity in water distribution, along with efficient gas transport, facilitates more effective electrochemical reactions, resulting in a ~5 % reduction in cell potential at a current density of 1000 mA cm⁻² compared to the parallel design. These findings highlight the advantages of the mesh-type flowfield in addressing mass transport challenges, positioning it as a promising solution for a wide range of PEMWE applications.

Authors: Wu, Y; Wen, Y; Malone, I; Tengattini, A; Helfen, L

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Journal of Power Sources
• Volume: 648
• Article number: 237396
• Publication date: 2025-05-21
• Acceptance date: 2025-05-14
• DOI: 10.1016/j.jpowsour.2025.237396
• EISSN: 1873-2755
• ISSN: 0378-7753
• Language: English
• Keywords: polymer electrolyte membrane water electrolysers; mesh-type flow-field; mass transport; neutron imaging