报告人：WANG Chongmin 美国西北太平洋国家实验室首席科学家
Over the last decades, we have witnessed tremendous progress on the development of aberration corrected scanning/transmission electron microscopy. As a result of this development, imaging and spectroscopying of materials at atomic scale appear to be a routine practice. The question now comes to how we extend these methodologies to analyze material process underreaction or operating condition, typically such as real time observation of catalytic process, oxidation/reduction, and charge and mass transport during battery operation. Approaches that are employed to provide in-situ observation of chemical reactions and microstructural evolution include, but are not limited to, the use of differential pumping technologies, the modification of sample holders to enable the application of an external stimulus such as an electromagnetic field or stress, using thin membrane closed cells for experiments involving liquids or gases, and use of liquid with low vapor pressure. In view of these developments, I will in this presentation focus on in-situ techniques that developed for probing into the structural and chemical information of energy storage materials, highlighting direct observation of structural evolution, phase transformation and their correlation with mass and charge transport, providing insights, representatively, as how does active materialfade during the cyclic charging and discharging of a battery, why does metal-air battery reaction product show peculiar morphological features, and how does nanoparticle interact in a liquid. Ultimately, direct in-situ observation provides insight for designing of better materials. In perspective, challenges and possible direction for further development of in-situ S/TEM imaging and spectroscopic methods for both functional and structural materials will also be discussed.
WANG Chongmin received his B.Sc. and M.Sc.in physics from Lanzhou University in China and Ph.D. in Materials Science and Engineering from University of Leeds, UK. He worked at Max-Planck Institute for Metal Research in Stuttgart in Germany as an Alexander von Humboldt Research Fellow, National Institute for Materials Science in Japan, and Lehigh University, focusing on atomic level study of grain boundary structure and chemistry using S/TEM. He is currently a chief scientist at Pacific Northwest National Laboratory and his research interests include the state of the art S/TEM imaging and spectroscopy and their application to materials characterization, especially in situ and operando S/TEM techniques for energy materials. He is one of the pioneers on in-situ TEM technique for rechargeable battery research, which has earned him prestigious honors, including the2016 MRS Innovation in Materials Characterization Award (shared with Frances Ross of IBM T. J. Waterson Research Center and Niels de Jonge of Leibniz Institute for New Materials, Germany); 2017 PNNL Laboratory Director’s Award for Exceptional Scientific Achievement; 2016 Journal of Materials Research(JMR) Paper of the Year Award; 2012 Microscopy Today Innovation Award. He is also the recipient ofR&D100 Award, Rowland Snow Award from the American Ceramic Society, Outstanding Invention Award from Japanese Science and Education Committee, PNNL Exceptional Contribution Awards, PNNL Pathway to Excellence Award (2017 and 2013). He has published 370 journal papers and several book chapters, including 2 in Science, 2 in Nature Nanotechnology, 1 Nature Materials, 1 in Nature Energy, and 4 in Nature Communications, with a total citation of 17000 and an H-index of 65,and delivered 70 invited talks. He is serving as the principal editor of Journal of Materials Research and is a Fellow of Materials Research Society.