The Effect of Cell Compression and Cathode Pressure on Hydrogen Crossover in PEM Water Electrolysis

authored by: Agate Martin, Patrick Trinke, Markus St hler, Andrea St hler, Fabian Scheepers, Boris Bensmann, Marcelo Carmo, Werner Lehnert, Richard Hanke-Rauschenbach
Abstract: Hydrogen crossover poses a crucial issue for polymer electrolyte membrane (PEM) water electrolysers in terms of safe operation and efficiency losses, especially at increased hydrogen pressures. Besides the impact of external operating conditions, the structural properties of the materials also influence the mass transport within the cell. In this study, we provide an analysis of the effect of elevated cathode pressures (up to 15 bar) in addition to increased compression of the membrane electrode assembly on hydrogen crossover and the cell performance, using thin Nafion 212 membranes and current densities up to 3.6 A cm-2. It is shown that a higher compression leads to increased mass transport overpotentials, although the overall cell performance is improved due to the decreased ohmic losses. The mass transport limitations also become visible in enhanced anodic hydrogen contents with increasing compression at high current densities. Moreover, increases in cathode pressure are amplifying the compression effect on hydrogen crossover and mass transport losses. The results indicate that the cell voltage should not be the only criterion for optimizing the system design, but that the material design has to be considered for the reduction of hydrogen crossover in PEM water electrolysis.
Organisation(s): Section Electrical Energy Storage Systems
External Organisation(s): Forschungszentrum Jülich
Queen's University Kingston
RWTH Aachen University
Type: Article
Journal: Journal of the Electrochemical Society
Volume: 169
ISSN: 0013-4651
Publication date: 05.01.2022
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Surfaces, Coatings and Films, Electrochemistry, Materials Chemistry
Sustainable Development Goals: SDG 7 - Affordable and Clean Energy
Electronic version(s): https://doi.org/10.1149/1945-7111/ac4459 (Access: Open)