Materials Science Research Lecture
***Refreshments at 3:45pm in Noyes lobby
Abstract:
This talk will examine the history and promise of a highly desirable lithium-ion battery cathode material system that exhibits both extremely high initial energy densities along with well-documented voltage and lithium inventory stability issues. The lithium-rich/manganese-rich (LMR) class of battery materials has been under investigation for over 25 years and while there has been incremental progress in improving stability and performance, there has been a persistent lack of agreement around the actual structural nature of the material and the source of its unusual functionality and instability. As produced, the material exhibits a dual-phase composition (consisting of segregated nano-domains, or a biphasic solid solution with a crystalline superstructure, depending on synthetic route) and undergoes a significant crystallographic reorganization when delithiated for the first time. Subsequent use typically shows very high specific capacity values (up to 300 mAh/g) but this comes with a rapid collapse in operational potential as the material transforms from the initial layered structure into a spinel structure during electrochemical cycling. A new approach to stymieing this undesirable transition will be disclosed: utilizing an ultra-rapid quench step that locks in an unusually entropic crystallographic state over several length scale. LMR frozen in this non-equilibrium condition is substantially more functional and stable than identical material processed without quenching. Various results exploring this effect will be discussed, and practical implications of this finding will be explored with a pathway to commercialization in mind.
More about the Speaker:
Jay is a material scientist with over 25 years of technical, business, and academic experience. His career has been focused on understanding and developing electrochemical materials and systems with a focus on lithium-ion batteries, energy policy, and innovation theory. He is a professor in the Materials Science and Engineering & Engineering and Public Policy departments, and holds the Trustee Chair in Energy, at Carnegie Mellon University, where he also served for 6 years as the director of the Wilton E. Scott Institute for Energy innovation.
Whitacre developed a novel aqueous battery chemistry that was manufactured and sold by Aquion Energy, a company he founded in 2008 that produced and shipped over 30 MWh of energy storage worldwide. More recently he founded Stratus Materials, a company focused on commercializing next-generation cathode materials for electric vehicle batteries. Earlier in his career, he was a Senior Member of the Technical Staff at the Jet Propulsion Laboratory/Caltech, where he worked as an energy materials technologist, system engineer, and a mission cognizant engineer.
Jay has numerous honors to his name including the 2014 Caltech/Resnick Sustainability Institute Resonate Award, the 2015 Lemelson-MIT Prize for Innovation, the 2017 Leigh Ann Conn Prize for Renewable Energy (bestowed by the University of Louisville), and is a Fellow of the National Academy of Inventors. He has advised over 25 Ph.D. students, authored or co-authored over 135 peer review papers and is an inventor on over 40 patents. Jay holds a BA in Physics from Oberlin College in 1994 as well and Ph.D. in Materials Science and Engineering from the University of Michigan.