Current Interrupt Technique to Fully Characterize PEMWE Cells

verfasst von

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.

Organisationseinheit(en)

Fachgebiet Elektrische Energiespeichersysteme

Externe Organisation(en)

Siemens AG

Typ

Artikel

Journal

Journal of the Electrochemical Society

Band

171

Anzahl der Seiten

12

ISSN

0013-4651

Publikationsdatum

18.03.2024

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Physik der kondensierten Materie, Oberflächen, Beschichtungen und Folien, Elektrochemie, Werkstoffchemie

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://doi.org/10.1149/1945-7111/ad3057 (Zugang: Offen)