Abstract
Spontaneously formed passivation layers, such as oxides on the aluminum surface, can enable many important applications by blocking the diffusion of the reacting species. A passivation layer, often called “solid electrolyte interphase”, also covers the lithiated graphite, lithiated silicon, and lithium metal electrodes in battery cells due to spontaneous electrolyte reduction reactions. This passivation layer must have “selective” transport properties: blocking electrons from attacking the electrolytes, while allowing Li+ ion to pass through so the electrochemical reactions can continue. Despite the importance, their structure-property relationship is largely unknown due to their nanometer thickness.
Using reactive molecular dynamics and density functional theory calculations, the transport and mechanical properties can be predicted and the chemical and structural evolution of these passivation layers can be tracked. Several important examples will be discussed in this talk.
For the oxides formed on solid and liquid aluminum, it is more ductile and stretchable than the crystalline Al2O3. When it is embedded inside casting aluminum, the breaking point is at the Al/oxide interface, serving as fatigue cracking nucleation sites.  
For the SEI in Li-ion batteries, the fracture and delamination of the SEI on Si electrode are simulated, leading to design criteria for mechanically stable coated Si nanostructures and battery operating guidelines to mitigate capacity loss due to trapped Li and coating delamination. 

Short Bio
Dr. Yue Qi is an associate professor in the Chemical Engineering and Materials Science Department at Michigan State University. She received 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 Ph.D. study. After her Ph.D., she spent 12 years working at the Chemical Sciences and Materials Systems Lab, General Motors R&D Center. At GM, she developed multi-scale models starting from atomistic level 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 fundamental research on various topics and TMS Young Leader Professional Development Award. She transitioned from industry to academia in 2013 and quickly built the “Materials Simulation for Clean Energy” Lab at MSU. Recently, she received the 2017 TMS Brimacombe Medalist Award.