Asymmetric Bipolar Membrane for High Current Density Electrodialysis Operation with Exceptional Stability
Bipolar membranes (BPMs) enable isolated acidic/alkaline regions in electrochemical devices, facilitating optimized environments for electrochemical separations and catalysis. For economic viability, BPMs must attain stable, high current density operation with low overpotentials in a freestanding configuration. We report an asymmetric, graphene oxide (GrOx)-catalyzed BPM capable of freestanding electrodialysis operation at 1 A cm–2 with overpotentials <250 mV. Use of a thin anion-exchange layer improves water transport while maintaining near unity Faradaic efficiency for acid and base generation. Voltage stability exceeding 1100 h with an average drift of 70 μV/h at 80 mA cm–2 and 100 h with an average drift of −300 μV/h at 500 mA cm–2 and implementation in an electrodialysis stack demonstrate real-world applicability. Continuum modeling reveals that water dissociation in GrOx BPMs is both catalyzed and electric-field enhanced, where low pKa moieties on GrOx enhance local electric fields and high pKa moieties serve as active sites for surface-catalyzed water dissociation. These results establish commercially viable BPM electrodialysis and provide fundamental insight to advance design of next-generation devices.
Authors
- Lily Shiau
- Shane Ardo (ORCID: https://orcid.org/0000-0001-7162-6826)
- Justin C. Bui (ORCID: https://orcid.org/0000-0003-4525-957X)
- T. Nathan Stovall (ORCID: https://orcid.org/0000-0001-5808-5877)
- Adam Z. Weber (ORCID: https://orcid.org/0000-0002-7749-1624)
- Ahmet Kusoglu (ORCID: https://orcid.org/0000-0002-2761-1050)
- Chengxiang Xiang (ORCID: https://orcid.org/0000-0002-1698-6754)
- Harry Albert Atwater (ORCID: https://orcid.org/0000-0001-9435-0201)
- Éowyn Lucas (ORCID: https://orcid.org/0000-0002-8743-5722)
- Alexis T. Bell (ORCID: https://orcid.org/0000-0002-5738-4645)
- Kaiwen Wang (ORCID: https://orcid.org/0000-0002-1046-4525)
- Monica Hwang
- Emily Dunn
- Ellis Spickermann
Institutions
- California Institute of Technology (US)
- Lawrence Berkeley National Laboratory (US)
- University of California, Irvine (US)
- Department of Physics, Mathematics and Informatics (BY)
- Division of Materials Science and Engineering (AU)
- Irvine University (US)
- University of California, Berkeley (US)
Publication Details
- Journal
- ACS Energy Letters
- Published
- 2024-10-28
- DOI
- https://doi.org/10.1021/acsenergylett.4c01662
- Citations
- 23
- Primary Topic
- Membrane-based Ion Separation Techniques
- Type
- article
- Field-Weighted Citation Impact
- 3.87
Funders
- U.S. Department of Energy
- Advanced Research Projects Agency - Energy
- Office of Science
- Advanced Research Projects Agency
- National Defense Science and Engineering Graduate
- Basic Energy Sciences
- Army Research Office