Abstract
In recent years, alkaline exchange membrane water electrolysis (AEM-WE) has attracted a lot of attention for its potential cost reduction compared to traditional electrolysis systems. Despite this promise, challenges related to efficiency and stability must be effectively addressed to fully realise the potential of AEM-WE. This paper presents a comprehensive investigation of an AEM-WE single-cell including electrochemical impedance spectroscopy (EIS) in conjunction with the equivalent circuit model (ECM). For the first time distribution of relaxation times (DRT) analysis is performed on an AEM-WE cell, employing a reversible hydrogen electrode (RHE) as a reference electrode. Half-cell EIS measurements and subsequent DRT spectra are presented, clearly indicating anodic and cathodic half-cell reactions. The DRT analysis reveals five distinct loss mechanisms in the AEM-WE system. These include the hydrogen evolution reaction, the oxygen evolution reaction, and ionic transport losses occurring within the catalyst layers. Through a systematic variation of the operating parameters we successfully allocate DRT peaks to their respective physicochemical origins. The findings contribute valuable insights into the electrochemical processes within the AEM-WE single-cell, offering a better understanding of the underlying mechanisms and facilitating the target-oriented development of enhanced membrane electrode assemblies.
Original language | English |
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Article number | 234455 |
Journal | Journal of Power Sources |
Volume | 605 |
DOIs | |
Publication status | Published - 15 Jun 2024 |
Keywords
- Anion exchange membrane electrolysis
- Distribution of relaxation times
- Electrochemical impedance spectroscopy
- Reference electrode
ASJC Scopus subject areas
- Renewable Energy, Sustainability and the Environment
- Energy Engineering and Power Technology
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering