Advanced Membranes for Electrochemical Technologies

John Karnes | 21-ERD-013

Project Overview

Polyelectrolyte ion exchange membranes enable a class of electrochemical technologies where either (1) the spontaneous transfer of ions results in a usable electrical current or (2) application of an electrical potential drives an ionic current across the membrane. Proton exchange membranes (PEMs) are the industry standard, but the low pH operating environment necessitates platinum-group metal (PGM) electrodes and components. Anion exchange membranes (AEMs), which facilitate the transport hydroxide anions, are an appealing alternative. The high pH operating environment allows for the use of earth-abundant electrode and catalyst materials, reducing capital expense. However, the Technology Readiness Level (TRL) of AEM-based devices lags behind PEM technology: The AEM itself is the performance and operational lifetime bottleneck.

Our hybrid computational/experimental team used computer simulations to test polymer design ideas while standing up electrochemical test rigs and membrane synthesis capabilities in parallel. We successfully synthesized bespoke AEMs by an approach that allows for chemical crosslinking after casting and partial hydration of the membrane. This approach results in a mechanically and operationally robust membrane that resists excess water uptake. Our proof-of-principle work was demonstrated with water electrolyzers, showing order-of-magnitude improvements to operational lifetime. The team's work will continue in several new projects, including a multi-institution, externally-funded project that targets ethylene-generating CO2 electrolyzers.

Mission Impact

This work benefits Lawrence Livermore National Laboratory's ( LLNL) mission in two ways. In the first, this project represents an investment in a promising, but stalled, technology that addresses DOE's energy and environmental security missions. The reduced capital expense of AEM-based electrochemical technologies [versus industry-standard PEMs] makes widespread adoption more feasible. Secondly, the focused investigation of polyelectrolyte degradation allowed us to develop experimental and computational accelerated aging and characterization methods that are readily extensible to aging studies of programmatic materials. The particle-based simulations and methods developed in this work complement the continuum-based approach that guides most programmatic simulations and will enhance our fundamental understanding of aging nuclear weapons systems when implemented and adapted for materials of interest.

Publications, Presentations, and Patents

Karnes, John. J, and Ilan Benjamin. 2021. "Deconstructing the Local Intermolecular Ordering and Dynamics of Liquid Chloroform and Bromoform." The Journal of Physical Chemistry B 125 (14): 3629-37.

Barnett, Adam, John J. Karnes, Jibao Lu, Dale R. Major, James S. Oakdale, Kyle N. Grew, Joshua P. McClure, and Valeria Molinero. 2022. "Exponential Water Uptake in Ionomer Membranes Results from Polymer Plasticization." Macromolecules 55 (15): 6762-74.

Barnett, Adam, John J. Karnes, Auston L. Clemens, James S. Oakdale, and Valeria Molinero. 2023. "Post-Hydration Crosslinking of Ion Exchange Membranes to Control Water Content." The Journal of Physical Chemistry C 127 (11): 5613-21.

Clemens, Auston L., Buddhinie S. Jayathilake, John J. Karnes, Johanna J. Schwartz, Sarah E. Baker, Eric B. Duoss, and James S. Oakdale. 2023. "Tuning Alkaline Anion Exchange Membranes through Crosslinking: A Review of Synthetic Strategies and Property Relationships." Polymers 15 (6): 1534.

Auston L. Clemens, Megan Ellis, James S. Oakdale, Nikola A. Dudukovic, Sarah E. Baker, Eric B. Duoss "High Resolution 3D Printed Anion Exchange Membranes Expanding the Design Space of Electrochemical Reactors" (Poster Presentation, 2021 MRS Fall Meeting and Exhibit. Boston, MA, 6-8 December 2021).

Auston L. Clemens, Buddhinie S. Jayathilake, John J. Karnes, Sarah E. Baker, Eric B. Duoss, and James S. Oakdale "Crosslinking of Anion Exchange Membranes" (PowerPoint Presentation, Polymers for Fuel Cells, Energy Storage, and Conversion, Napa, CA,15-18 May 2022).

John J. Karnes, Adam Barnett, James S. Oakdale, Auston L. Clemens, Jackson K. Elowitt, and Valeria Molinero, "Simulating Water Uptake in Anion Exchange Membranes" (PowerPoint Presentation. American Chemical Society: Polymers for Fuel Cells, Energy Storage and Conversion, Napa, CA, 18 May 2022).

Jackson K. Elowitt, Adam Barnett, John J. Karnes, James S. Oakdale, and Valeria Molinero, "Effect of Chemical Degradation on the Structure and Water Uptake of Anion Exchange Membranes" (Poster Presentation, American Conference on Theoretical Chemistry 2022, Tahoe, CA, 25-28 July 2022).

Auston L. Clemens, Maira Ceron, Magi Yassa, Thomas Ferron, Adam Barnett, Joshua A. Hammons, Buddhinie S. Jayathilake, Valeria Molinero, John J. Karnes, and James S. Oakdale, "UV-Controlled Nitrene Crosslinking in Poly(phenylene oxide) Anion Exchange Membranes" (Poster Presentation, 243rd ECS Meeting, Boston, MA, 29 May 2023).

Ignacio J. Bombau, Jackson K. Elowitt, Shakkira Erimban, Matias H. Factorovich, Damian Scherlis, John J. Karnes, and Valeria Molinero, "Anion Exchange Membranes: The Effect of Degradation on Water Uptake, Structure and Mechanical Properties" (Poster Presentation, Gordon Research Conference: Chemistry and Physics of Liquids - Structural, Dynamic and Reactive Properties in the Liquid Phase, Holderness, NH, 2-3 August 2023).

John J. Karnes, Adam Barnett, Auston L. Clemens, Thomas J. Ferron, Magi Mettry-Yassa, Maira R. Ceron-Hernandez, Joshua A. Hammons, James S. Oakdale, Valeria Molinero,"Design, Testing, and Analysis of Ion Exchange Membranes by Molecular Simulation" (PowerPoint Presentation, American Chemical Society Fall 2023, San Francisco, CA, 17 August 2023).