報告人：Yue Qi

報告題目：From Atoms to Devices — Multiscale Modeling the Interfaces in Solid-State Batteries

報告時間：2025年6月23日（周一）上午9：30  

報告地點：物理與電子工程學院428會議室  

主辦單位：物理與電子工程學院、科學技術研究院  

報告人簡介：

Dr. Yue Qi is the Joan Wernig Sorensen Professor of Engineering at Brown University and serves as the Deputy Director of the Initiative for Sustainable Energy (ISE). She earned her B.S. in Materials Science and Engineering and Computer Science from Tsinghua University, followed by her Ph.D. from Caltech. For 12 years, she worked at General Motors R&D, developing multi-scale models to solve engineering challenges related to lightweight materials, fuel cells, and batteries. In 2013, she transitioned to academia, initially joining Michigan State University before moving to Brown University. Dr. Qi’s research focuses on multi-scale and multi-physics simulations, which are key to designing materials and interfaces critical to energy-efficient technologies. She has been recognized with several research awards, including the Feynman Prize in Nanotechnology and the Brimacombe Medal from the Minerals, Metals & Materials Society (TMS). In addition to her research, Dr. Qi is a strong advocate for diversity in STEM. She served as the inaugural Associate Dean for Inclusion and Diversity at Michigan State University and received Brown's Dean’s Award for Impact in DEI.

報告摘要：

The rapid advancement of fast Li-ion conductors has brought interface resistance and stability during cycling to the forefront of challenges for all-solid-state Li-ion batteries. This talk will delve into multiscale modeling of the interfaces, where charge transfer reactions occur and electrochemistry, physics, and solid mechanics intersect. The electrochemical effects were captured using a density functional theory (DFT)-informed band-alignment model that predicts the potential distribution within a solid-state battery. This model provides key insights into the potential drop, electrostatic dipole, and space-charge layer at the electrode/solid-electrolyte interface, reconciling previously conflicting experimental observations. Another critical challenge for high-energy-density solid-state batteries with Li-metal electrodes is the growth of soft Li dendrites within hard solid electrolytes. A DFT-informed phase-field method was developed to explain experimentally observed intergranular dendrite growth. It revealed that trapped electrons at grain boundaries and surfaces likely play a key role in reducing Li-ion mobility and nucleating metallic Li. Based on these findings, a new dendrite-resistance criterion has been proposed. Achieving a stable stripping process poses an even greater challenge than plating, as stripping removes Li atoms from the surface. To address this, we capture the mechanisms occurring across multiple length and time scales—such as interface interactions, vacancy hopping, and plastic deformation—by integrating DFT simulations, kinetic Monte Carlo methods, and continuum finite element models. By leveraging the self-affine nature of multiscale contacts, we predict the steady-state contact area as a function of stripping current density, interface wettability, and stack pressure. These modeling advancements will be integrated into a comprehensive framework to guide the design and development of next-generation all-solid-state Li-ion batteries.