"Modeling of the Interface and Interphases in Li-ion Batteries"
Prof. Yue Qi, Ph.D.
Department of Chemical Engineering & Materials Science Michigan State University, East Lansing, Michigan
April 11, 2016 at 3:30 P.M., 112 OHR (Oliver H. Raymond Civil Engineering Building)
One of the most significant challenges for current and future lithium ion batteries is the smart structure design at the nanoscale and the control of electron and ion transport at the electrode/electrolyte interface. This issue is further complicated by the existence of ultrathin interphase layers (IL) covering the electrode, forming a complex heterogeneous electrode/IL/electrolyte interface. New computational methods are being developed to critically examine the different pathways of electrons and ions crossing this complex interface, that are critical to charge transfer, degradation mechanisms, and interphase design. The electrochemical reactions responsible for electrolyte degradation are examined using Density functional theory (DFT)-based methods. Examples are rigorous voltage calibration in DFT calculations and estimation of irreversible capacity loss agreeing well with experimental measurements. In order to understand how to design interphase materials with higher ionic conductivity, the dominating diffusing carriers and their diffusion pathways are predicted, as a function of the voltage of the electrode. The chemical-mechanical degradation at the artificial coatings is further investigated by molecular dynamics simulations with ReaxFF. The insights gained from these simulations have enhanced our understanding on battery degradation mechanisms and inspired new designs across various length scales (nano to vehicle applications).
Dr. Yue Qi is an associate professor in the Chemical Engineering and Materials Science Department at Michigan State University. She received her dual-B.S. degrees in Materials Science and Engineering and Computer Sciences from Tsinghua University in 1996 and her Ph.D. in Materials Science from California Institute of Technology in 2001. She was a co-recipient of 1999 Feynman Prize in Nanotechnology for Theoretical Work during her PhD study. After receiving her Ph.D. degree, she spent 12 years working in the Chemical Sciences and Materials Systems Lab, General Motors R&D Center. She led a multi-scale modeling research effort to solve problems related to forming and machining of lightweight alloys, and developing energy materials for batteries and fuel cells. She won three GM Campbell awards for outstanding research on various topics and a TMS Young Leader Professional Development Award.
This seminar is hosted by the students of MRS-UK.