Refreshments served at 2:45 PM
Polymer Membranes for Large-Scale Energy Conversion and Storage
Abstract: New polymer membranes are needed to advance energy storage and conversion technologies for distributed and grid-scale applications. We have recently demonstrated new ion-conducting polymer membranes that have achieved excellent performance and long-lifetime stability in vanadium redox flow batteries, a leading technology candidate for deployment in renewable power networks and grid-scale energy storage systems with sizes ranging from 10s to 100s of megawatts.1,2 By tuning the nanoscopic self-assembly of the ionic domains in the polymers, we are able to increase the cycle life of the device by impeding vanadium ion transport through the membrane while facilitating high conductivity in the electrolyte to maintain the battery current density. For instance, by decreasing the vanadium permeability of the membrane by a factor of two, we have been able to double the lifetime of the device, which provides significant life-cycle cost savings. We have also demonstrated membranes with nearly zero vanadium permeability that show 100 % coulombic efficiency in flow battery charge-discharge cycling tests.3 Currently, we are working on demonstrating these membranes over 100s of charge-discharge cycles.
Anion exchange membranes have the potential to rid fuel cell technology of expensive precious-metal catalysts. Acidic fuel cells with NAFION® membranes require platinum, but anionic membranes that operate at high pH open the door for the use of silver and nickel fuel cell catalysts which would greatly decrease the cost of polymer fuel cell technology. We have developed new anion exchange membrane polymer structures that show exceptional stability under fuel cell conditions and have helped to increase the performance and lifetime of anion exchange membrane fuel cells.4
This talk will show how polymers with new chemical structures can be applied to many different types of batteries and other electrochemical devices. Common design principles and considerations for fabricating new ion exchange membranes for energy processes will be discussed.
1. Kim, S., J. Yan, B. Schwenzer, J. Zhang, L. Li, J. Liu, Z. Yang, M. A. Hickner, “Investigation of Sulfonated Poly(phenylsulfone) Membrane for Vanadium Redox Flow Batteries,” Electrochem. Comm. 2010, 12, 1650–1653.
2. Chen, D., S. Kim, V. Sprenkle, M. A. Hickner, “Composite blend polymer membranes with increased proton selectivity and lifetime for vanadium redox flow batteries,” J. Power Sources 2013, 231, 301-306.
3. Chen D., M. A. Hickner, E. Agar, E. C. Kumbur, “Optimized Anion Exchange Membranes for Vanadium Redox Flow Batteries,” ACS Appl. Mater. Interfaces 2013, 5 (15), 7559–7566.
4. Li, N., Y. Leng, M. A. Hickner, C.-Y. Wang, “Highly Stable, Anion Conductive Comb-shaped Copolymers for Alkaline Fuel Cells,” J. Am. Chem. Soc. 2013, 135 (27), 10124–10133.
Biography: Michael A. Hickner received his Ph.D. in Chemical Engineering from Virginia Tech in 2003. In graduate school he spent time in the fuel cell group at Los Alamos National Laboratory developing novel aromatic proton exchange membranes for both hydrogen and direct methanol fuel cells. Before joining the Department of Materials Science and Engineering at Penn State in 2007, he was a postdoctoral researcher and then staff member at Sandia National Laboratories in Albuquerque, NM. His research group at Penn State is focused on the synthesis and properties of ion-containing polymers, measurement of water-polymer interactions using spectroscopic techniques, and the study of self- and directed assembly of polymeric nanostructures for fast transport. He has ongoing projects in new polymer synthesis, fuel cells, batteries, water treatment membranes, and organic electronic materials. Hickner’s work has been recognized by Young Investigator Awards from ONR and ARO (2008), a 3M Non-tenured Faculty Grant (2009), the Rustum and Della Roy Innovation in Materials Research Award (2013), and a Presidential Early Career Award for Scientists and Engineers from President Obama in 2009. He has seven US and international patents and over 100 peer-reviewed publications since 2001 (H-index of 30) that have been cited more than 5900 times.
Faculty Host: Uday Pal
Student Host: Christa Hoskin