MSE Seminar Series

Friday, April 9, 2021 @11:40am
*Remote course - Zoom link will be provided

Miaofang Chi, PhD,
Sr. Staff Scientist, Center for Nanophase Materials Sciences,
Oak Ridge National Laboraratory

presents

Beyond structural and chemical imaging in a TEM -- new opportunities for understanding interfaces in energy materials

ABSTRACT:
Electron microscopy has enabled imaging and chemical analysis of materials at the single atom level. Substantial contributions to energy materials research have been made in the past decade, especially to the investigation of interfaces, which often act as the bottleneck in next generation energy systems. Many critical interfacial questions, however, still remain, which require knowledge not only of atomic-scale structure and chemistry, but also of electrons and their dynamic evolutions under operation conditions. Recent developments in scanning transmission electron microscopy (STEM), including atomic-scale in situ imaging, four-dimensional (4D)-STEM, and monochromated EELS have opened up unprecedented opportunities.  In this presentation, I will introduce these capabilities and highlight examples demonstrating how these capabilities allow us to (1) reveal the origin of high interfacial resistance and of the unexpected dendrite growth in all-solid-state batteries; (2) understand charge transfer phenomena in heterogenous catalysts; and (3) directly observe anionic electrons in electrides for the first time. Perspectives for the future advancement of these new STEM techniques for research into emerging energy materials will also be provided.


BIOGRAPHY:
Miaofang Chi is a senior staff scientist at the Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National Laboratory (ORNL). Her research is focused on understanding interfacial ion transport and charge transfer in energy materials. She received her Ph.D. in Materials Science and Engineering from University of California, Davis in 2008. Her primary research interests lie in advancing and applying novel electron microscopy techniques in energy and nanotechnology research, especially in developing a better understanding of interfacial charge transfer behavior in energy storage and nanoelectronics systems. She was awarded the Burton Metal by the Microscopy Society of America (2016). She received the ORNL Director’s Award for Outstanding Individual Accomplishment in Science and Technology (2015) and the ORNL’s Early Career Research Award (2015). Miaofang is the author and co-author of more than 150 peer-reviewed journal articles. She was named to the Clarivate’s 2018 and 2020 list of Highly Cited Researchers.