Connecting Polymer Microstructure to Ion and Proton Conductivity

Connecting Polymer Microstructure to Ion-and Proton Conductivity art

Overview: In typical polymer-salt electrolyte systems, the ions move in concert with the polymer dynamics. The Winey group has applied their new understanding of ionomer morphologies to pioneer an alternative strategy for ion conductivity in polymers based on the design concepts of sequestering the ions into percolated aggregates and dissociating ion mobility from polymer mobility. For example, her group has demonstrated that the double gyroid morphology has higher ion conductivity than hexagonally-packed cylinders or layered morphologies by accessing these distinct morphologies in the same polymer as a function of temperature. This finding highlights the importance of continuous conductive domains. The Winey has also applied these concepts to proton conductivity in hydrated acid-containing polymers. First in a layered morphology and more recently in various non-periodic co-continuous morphologies, the group has reported proton conductivities in fluorine-free polymers that are comparable or superior to widely used fluorinated polymers when hydrated. They have also collaborated with molecular dynamics simulation experts to reveal interconnections between polymer microstructures, nanoscale morphologies, and conductivity. Finally, given the strong thermodynamic driving forces for the self-assembly of ionic and acid groups in these polymers, the group has developed solvent-based and thermal processing routes to manipulate the morphologies and thereby establish robust structure-property relationships that further understanding.

  1. E. B. Trigg, T. W. Gaines, M. Maréchal, D. E. Moed, P. Rannou, K. B. Wagener, M. J. Stevens, K. I. Winey*, Nature Materials, 17, 725-731, 2018. “Self-assembled highly ordered acid layers in precisely sulfonated polyethylene produce efficient proton transport.” https://doi.org/10.1038/s41563-018-0097-2; 64 citations
  2. Yan JACS cover 2020
    Lu Yan, C. Rank, S. Mecking, K. I. Winey*, Journal of the American Chemical Society, 142, 857-866, 2020. “Gyroid and other ordered morphologies in single-ion conducting polymers and their impact on ion conductivity.”
    https://pubs.acs.org/doi/full/10.1021/jacs.9b09701; 6 citations
  3. B. A. Paren, B. A. Thurston, A. Kanthawar, W. J. Neary, A. Kendrick, M. Maréchal, J. G. Kennemur, M. J. Stevens,* A. L. Frischknecht,* K. I. Winey*, Chemistry of Materials, 33, 6041-6051, 2021. “Fluorine-free precise polymer electrolyte for efficient proton transport: Experiments and simulations.” https://doi.org/10.1021/acs.chemmater.1c01443  
  4. M. Win, K. I. Winey*, A. L. Frischknecht*, Macromolecules, 56, 9905-9913, 2023. “Morphology−Diffusivity Relationships in Fluorine-Free Random Terpolymers for Proton-Exchange Membranes.” https://doi.org/10.1021/acs.macromol.3c01707
  5. Chemistry of Materials October 2024 cover
    Daniel L. Vigil, Benjamin T. Ferko, Anne Saumer, Stefan Mecking, Mark J. Stevens*, Karen I. Winey*, Amalie L. Frischknecht*, Chemistry of Materials, 36, 9970-9979, 2024. “Partial solvation of lithium ions enhances conductivity in a nanophase-separated polymer electrolyte.” https://doi.org/10.1021/acs.chemmater.4c02398
  6. Sol Mi Oh, Victoria S. Lee, William F. Drayer, Max S. Win, Lindsay F. Jones, Courtney M. Leo, Justin G. Kennemur, Amalie L. Frischknecht*, Karen I. Winey*, JACS Au, 5, 2641–2653, 2025. “Effect of sulfonation level on the percolated morphology and proton conductivity of hydrated fluorine-free copolymers: Experiments and simulations” https://doi.org/10.1021/jacsau.5c00218