Advanced ionomer materials for electrochemical separations

Advanced ionomer materials for electrochemical separations

Christopher G. Arges

Research Engineer

CASE Senior Scientist Affiliate

Argonne National Laboratory

University of Chicago

 Abstract

Chemical separations account for 10-15% of the overall U.S. energy use. Achieving ambitious decarbonization goals by the middle of the century necessitate electrified chemical processes such as electrochemically mediated separations. Furthermore, the transition to clean energy requires securing critical mineral and material (CMM) supply chains. Extracting CMMs from mining effluents and recycled energy technology components will require breakthroughs in the selectivity and performance of separations technologies. This talk commences with a broad overview of various mechanisms for achieving selective ion separations in electrochemical platforms. Polymeric ion-exchange membranes, a type of ionomer material, are a key component in the separation unit and their molecular design governs partitioning behavior and diffusion coefficients. Our group has leveraged nanofabrication, advanced metrology, molecular dynamics simulations, and machine learning to measure and predict activity coefficients in ionomer materials. The activity coefficients influence partitioning behavior and affect ionic conductivity. The latter half of the talk connects insights from model thin film studies to observations in organic acid separations using electrodialysis and electrodeionization units. The talk concludes with examples of pH-assisted electrochemical separations using bipolar membranes in membrane capacitive deionization units. The examples include selective copper and phosphate recovery from model wastewater solutions and selective capture of lithium from geothermal brines while concurrently producing lithium hydroxide – which is the desired feedstock in the manufacture of lithium-ion batteries.

Biography

Chris Arges is a Research Engineer at Argonne National Laboratory and a CASE Senior Scientist Affiliate in the Pritzker School of Molecular Engineering at the University of Chicago. He was formerly a Professor in Chemical Engineering at Penn State and Louisiana State University. Chris’s research interests are at the intersection of polymer science and electrochemical engineering. Chris earned his B.S. in Chemical Engineering at the University of Illinois at Urbana-Champaign and a PhD in Chemical Engineering at the Illinois Institute of Technology. He was postdoctoral scholar at the Pritzker School of Molecular Engineering at the University of Chicago. Chris is the recipient of the NSF CAREER Award, the Electrochemical Society-Toyota Young Investigator Fellowship, and the 3M Non-Tenured Faculty Award.