Understanding electrical under- and overshoots in proton exchange membrane water electrolysis cells

verfasst von

Christoph Immerz, Boris Bensmann, Patrick Trinke, Michel Suermann, Richard Hanke-Rauschenbach

Abstract

Ability of dynamic operation seems to be an important feature of proton exchange membrane water electrolyzers (PEMWE) to become a relevant part of the future energy system. However, only few fundamental analyzes of the dynamic behavior on short time scales are available in the literature. Therefore, this contribution aims to give insights into the most fundamental transient behavior of a PEMWE cell by an experimental analysis on the laboratory scale and a model based description of the ongoing phenomena. Experimental voltage and current controlled load step are carried out and analyzed by methods adapted from fuel cell characterization. The experimental analysis revealed that load steps are a combination of an instantaneous characteristic followed by dynamics of higher order dependent on activation, mass transfer and temperature effects. Potentiostatic downward steps to very low cell voltages can lead to current density reversal phenomena with highly negative peak current densities. By means of a simple prototype model analysis, these reversal processes are analyzed and the consequences of the phenomena are estimated. The simulation results indicate that a reversal of the cell current density can be attributed to a change of capacitive rather than faradaic currents, meaning that internal electrolysis processes are not involved.

Organisationseinheit(en)

Institut für Elektrische Energiesysteme
Fachgebiet Elektrische Energiespeichersysteme

Typ

Artikel

Journal

Journal of the Electrochemical Society

Band

166

Seiten

F1200-F1208

ISSN

0013-4651

Publikationsdatum

05.11.2019

Publikationsstatus

Veröffentlicht

Peer-reviewed

Ja

ASJC Scopus Sachgebiete

Elektronische, optische und magnetische Materialien, Erneuerbare Energien, Nachhaltigkeit und Umwelt, Oberflächen, Beschichtungen und Folien, Elektrochemie, Werkstoffchemie

Ziele für nachhaltige Entwicklung

SDG 7 – Erschwingliche und saubere Energie

Elektronische Version(en)

https://www.repo.uni-hannover.de/bitstream/123456789/10312/1/Immerz_2019_J._Electrochem._Soc._166_F1200.pdf (Zugang: Offen)
https://doi.org/10.1149/2.0881914jes (Zugang: Geschlossen)