Date(s) - 12/02/2019
9:35 am - 10:25 am
New Engineering Building – Room 201
Gary Koenig, Ph.D.
University of Virginia
“Fabrication and Characterization of Thick Battery Electrodes”
Lithium-ion batteries have become very successful in the consumer electronics industry; however, improvements are still needed with regards to cost and performance for greater market penetration into larger scale applications such as electric vehicles and stationary energy storage. While much progress has been made historically with regards to materials chemistry for improving battery performance, factors such as the distribution of the active material particles within the battery electrode and optimizing cell geometry also are significant factors.
Our group has focused its efforts on synthesizing battery active material particles with controllable morphologies and trying to understand how their organization within battery electrodes impacts electrochemical properties. Most lithium-ion battery electrodes, including those in commercial cells, are comprised of composites containing both electroactive materials and inactive carbon conductive additives and binders. Eliminating the inactive components would result in increases in energy density at the cell level. Also, thicker electrodes will result in higher cell energy density. Our group has been investigating the properties of thick electrodes comprised of only electroactive materials. Such electrodes have very high energy density, but also have relatively low electronic conductivity and longer ion diffusion pathways. Thus, they serve as a unique system to study transport properties through porous thin films. This presentation will discuss recent progress in understanding the limitations of these thick porous electrodes. In particular, probing the in situlocation where lithiation/delithiation occurs during electrochemical charge/discharge using neutron imaging of batteries fabricated with these thick electrodes will be described. Neutron imaging provides insights into the charge/discharge processes for different electrode processing conditions and operational current densities. Experimental results will be compared to an electrochemical model and potential improvements to both will be discussed.
Prof. Gary Koenig completed a B.S. in Chemical Engineering at The Ohio State University in 2004, and then received a Ph.D. in Chemical Engineering from the University of Wisconsin-Madison in 2009 with advisor Nicholas Abbott. The Ph.D. thesis involved the study of the interactions of colloidal particles in structured solvents. After graduate school, Dr. Koenig worked as a Postdoctoral Associate at the Department of Energy’s Argonne National Laboratory in the Chemical Sciences and Engineering Division under the supervision of Dr. Ilias Belharouak in the group of Dr. Khalil Amine. The postdoctoral project was the development of a new lithium-ion battery cathode material with an internal concentration gradient at the particle level. In 2012, Dr. Koenig began an appointment as an Assistant Professor at University of Virginia in the Department of Chemical Engineering, being promoted to Associate Professor in 2018. Research interests include the synthesis and characterization of battery electrode active materials and the impacts of particle morphology and organization on electrode properties.