简介: |
Integrating material properties and microstructures
into battery failure modeling
Yue Qi
Abstract
Most lithium ion battery electrodes experience volume changes associated with Li concentration changes within the host particles during charging and discharging. Electrode failure, in the form of fracture or decrepitation, can occur as a result of repeated volume changes. Besides the volume change many electrode materials change their elastic properties, fracture energies, bonding natures upon lithiation. However, previous electrode mechanics model have always assumed constant materials properties. Recently, based on first principle calculations, we found graphite is stiffened and silicon is softened with increasing Li concentration, and the change can be as much as three fold. A mathematical model of diffusion induced stress and fracture tendency in battery electrodes has been developed to include varying material properties. Our results underscore the importance of integrating the material properties into Li-ion battery failure modeling.
Bio:
Dr. Yue Qi is a Staff Research Scientist working on computational materials sciences at Chemical Sciences and Materials Systems Lab, General Motors R&D Center, Warren, MI. She completed her B.S. degrees on Materials Science and Computer Science at Tsinghua University, China in 1996. She received her PhD in Materials Science from California Institute of Technology in 2001, then joined GM as a Sr. Research Scientist. Her research interest is using multi-scale modeling to bridge chemistry and mechanics, in the areas of light weight materials, coatings, fuel cells and Li-ion batteries. For her previous work, she received 2009 GM Campbell awards for “Multi-scale Modeling of High-temperature Deformation in Aluminum” and “Fundamentals of Interfacial Tribology”, 2006 GM Campbell Award for “Advances in Nano-scale Plasticity”, and was the corecipient of 1999 Feynman Prize in Nanotechnology for Theoretical Work with Dr. T. Cagin and Prof. W. A. Goddard III (PhD advisor). Her recent research topic is on “integration of material properties into Li-ion battery failure modeling”.
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