嘉宾介绍
肖鹏昊
戴尔豪斯大学物理与大气科学系助理教授
Dr. Penghao Xiao is an assistant professor in the Department of Physics and Atmospheric Science at Dalhousie University in Halifax, Canada. His research focuses on simulation of materials from first principles, with a particular interest on the kinetic processes that dictates materials’ synthesis, performance, and degradation. Before joining Dalhousie in 2021, Dr. Xiao obtained his Ph.D. from the University of Texas at Austin under the supervision of Dr. Graeme Henkelman. He did his postdoc trainings at Lawrence Berkeley National Laboratory with Dr. Gerbrand Ceder, and then at Lawrence Livermore National Laboratory with Dr. Brandon Wood.
内容抢先读
Atomic-scale processes under electric fields or applied voltage are challenging to observe directly but can be explored through first-principles simulations. In this talk, I will highlight our recent advances in modeling such processes with millisecond timescale resolution, enabling direct comparison with experiments.Three case studies will be presented. First, we show that electric fields can drive dislocation motion in ZnS by lowering migration barriers, as revealed by DFT calculations incorporating field effects. Second, in LiNiO₂—a high-energy-density Li-ion battery cathode—we reproduce the first-cycle irreversible capacity loss and reveal a shift in the rate-limiting step from Li diffusion to phase transition near full charge. Surface densification during cycling suppresses phase nucleation, severely hindering delithiation below 25% Li, consistent with experiments. Third, we develop a method to search for saddle points under constant voltage, allowing the electron count to adjust dynamically. Using this, we compare two charge transfer pathways in the oxygen evolution reaction on RuO₂.These examples demonstrate how field- and voltage-aware atomistic simulations can reveal hidden mechanisms in materials behavior, offering predictive insights into energy-related processes such as plastic deformation, battery degradation, and electrocatalysis.
讲座信息
时间：2025年6月20日（周五）10:00—11:00地点：清华大学汽研所301