Details
| Original language | English |
|---|---|
| Article number | 054505 |
| Journal | Journal of the Electrochemical Society |
| Volume | 170 |
| Issue number | 5 |
| Publication status | Published - 17 May 2023 |
Abstract
This work analyses the water transport and ionic losses in bipolar membranes at water electrolysis cells conditions. In common bipolar setups, water is split at the bipolar interface between the anion exchange membrane (AEM) and the cation exchange membrane (CEM). Accordingly, ions (protons and hydroxide ions) are transported to the electrodes, carrying the water out of both membranes via electro-osmotic drag. These outfluxes plus the required water amount for the splitting process have to be compensated by water diffusion towards the bipolar interface. The effect of water transport on the polarisation behaviour is additionally shown. Mayerhöfer et al. [ACS Appl. Energy Mater., 3, 9635 (2020)] and Oener et al.[ACS Energy Lett., 6, 1 (2021)] decreased polarization losses and increased the current density range by reducing either the AEM or the CEM thickness, respectively. Our model validates these improvements by calculating the limiting current density caused by dehydration of the membranes. Further analysis shows that thinner AEM thicknesses decrease membrane voltage losses more than thinner CEM due to lower ionic conductivities and faster dehydration of AEMs. Thin CEMs on the other hand, are more efficient at increasing the limiting current density.
ASJC Scopus subject areas
- Materials Science(all)
- Electronic, Optical and Magnetic Materials
- Energy(all)
- Renewable Energy, Sustainability and the Environment
- Physics and Astronomy(all)
- Condensed Matter Physics
- Materials Science(all)
- Surfaces, Coatings and Films
- Chemistry(all)
- Electrochemistry
- Materials Science(all)
- Materials Chemistry
Sustainable Development Goals
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In: Journal of the Electrochemical Society, Vol. 170, No. 5, 054505, 17.05.2023.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Modelling Water Transport Limitations and Ionic Voltage Losses in Bipolar Membrane Water Electrolysis
AU - Weiland, Oskar
AU - Trinke, Patrick
AU - Bensmann, Boris
AU - Hanke-Rauschenbach, Richard
N1 - Funding Information: We thank Ricarda Weiland for her comments, which greatly improved the quality of the manuscript in the final stages of writing. In addition, we gratefully acknowledge the financial support by the Federal Ministry of Education and Research in the framework of ReveAl (project number 03SF0662A).
PY - 2023/5/17
Y1 - 2023/5/17
N2 - This work analyses the water transport and ionic losses in bipolar membranes at water electrolysis cells conditions. In common bipolar setups, water is split at the bipolar interface between the anion exchange membrane (AEM) and the cation exchange membrane (CEM). Accordingly, ions (protons and hydroxide ions) are transported to the electrodes, carrying the water out of both membranes via electro-osmotic drag. These outfluxes plus the required water amount for the splitting process have to be compensated by water diffusion towards the bipolar interface. The effect of water transport on the polarisation behaviour is additionally shown. Mayerhöfer et al. [ACS Appl. Energy Mater., 3, 9635 (2020)] and Oener et al.[ACS Energy Lett., 6, 1 (2021)] decreased polarization losses and increased the current density range by reducing either the AEM or the CEM thickness, respectively. Our model validates these improvements by calculating the limiting current density caused by dehydration of the membranes. Further analysis shows that thinner AEM thicknesses decrease membrane voltage losses more than thinner CEM due to lower ionic conductivities and faster dehydration of AEMs. Thin CEMs on the other hand, are more efficient at increasing the limiting current density.
AB - This work analyses the water transport and ionic losses in bipolar membranes at water electrolysis cells conditions. In common bipolar setups, water is split at the bipolar interface between the anion exchange membrane (AEM) and the cation exchange membrane (CEM). Accordingly, ions (protons and hydroxide ions) are transported to the electrodes, carrying the water out of both membranes via electro-osmotic drag. These outfluxes plus the required water amount for the splitting process have to be compensated by water diffusion towards the bipolar interface. The effect of water transport on the polarisation behaviour is additionally shown. Mayerhöfer et al. [ACS Appl. Energy Mater., 3, 9635 (2020)] and Oener et al.[ACS Energy Lett., 6, 1 (2021)] decreased polarization losses and increased the current density range by reducing either the AEM or the CEM thickness, respectively. Our model validates these improvements by calculating the limiting current density caused by dehydration of the membranes. Further analysis shows that thinner AEM thicknesses decrease membrane voltage losses more than thinner CEM due to lower ionic conductivities and faster dehydration of AEMs. Thin CEMs on the other hand, are more efficient at increasing the limiting current density.
UR - http://www.scopus.com/inward/record.url?scp=85159724375&partnerID=8YFLogxK
U2 - 10.1149/1945-7111/acd02c
DO - 10.1149/1945-7111/acd02c
M3 - Article
AN - SCOPUS:85159724375
VL - 170
JO - Journal of the Electrochemical Society
JF - Journal of the Electrochemical Society
SN - 0013-4651
IS - 5
M1 - 054505
ER -