Current Interrupt Technique to Fully Characterize PEMWE Cells

authored by: Tobias Krenz, Torben Gottschalk, Lennard Helmers, Patrick Trinke, Boris Bensmann, Richard Hanke-Rauschenbach
Abstract: It is common practice to characterize cells in polymer electrolyte membrane water electrolysis (PEMWE) using electrochemical impedance spectroscopy (EIS) and Tafel analysis, which require special equipment and operation procedures. Additionally, these techniques are not suitable for large industrial size cells with very low impedances. We present a simpler approach based on a novel evaluation of the current interrupt (CI) technique. The CI technique utilizes the voltage response after an instantaneous drop of electric current to identify the ohmic resistance R _Ω, charge transfer resistance R _ct and double-layer capacity C _dl in a simplified equivalent circuit (EC) of the cell. A direct link to results of typical EIS and Tafel analysis can be defined by using the improved CI method which considers a non-linear activation resistance instead of a constant charge transfer resistance. Thereby, access to equivalent information as the established standard method is granted, while being applicable to all cell and stack sizes without requiring special equipment (e.g. impedance spectrometer). The agreement with experimental data is significantly improved over the assumption of a constant charge transfer coefficient. Consistency of the proposed interpretation with explicit EIS and Tafel analysis is demonstrated and options for industrial application of the evaluation scheme are discussed.
Organisation(s): Section Electrical Energy Storage Systems
External Organisation(s): Siemens AG
Type: Article
Journal: Journal of the Electrochemical Society
Volume: 171
No. of pages: 12
ISSN: 0013-4651
Publication date: 18.03.2024
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Renewable Energy, Sustainability and the Environment, Condensed Matter Physics, 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/ad3057 (Access: Open)