报告内容简介

Secondary ion batteries, especially, lithium ion battery (LIB), play an important role in our daily life such as portable devices, electric car and station storage devices. For next generation batteries, we would like to improve their energy density, cycling stability, and safety issues which demand us to develop new electrode materials. My research focuses on the study of the reaction mechanism of the conversion compounds for secondary ion batteries.

In this talk, I would like to show our efforts of using advanced (scanning-) transmission electron microscopy ((S)TEM) to study the redox reactions of the electrode materials for secondary ion batteries. With/Combining different TEM techniques (including in situ TEM and diffraction, HAADF-STEM, and STEM-electron energy-loss spectroscopy (EELS)), researchers are able to probe local structural and chemical information of electrode materials, at a new era of resolution. Therefore, knowledge about the reaction dynamics and kinetics can be retrieved at different states of charging (discharging). I will introduce the background knowledge of battery and TEM, and then show the cases on the conversion compounds for lithium/sodium ion batteries, for examples, in the cases of ion flourides used for cathode, we investigated the structural and chemical ordering at nanoscale and revealed some unexpected phenomenon. In case of NiO, the role of reaction pathways from near-surface redox to interior redox is highlighted which is supposed to affect the rate capability.

报告人

Dong Su obtained his Ph.D in condensed matter physics from Nanjing University in 2003. He did his Postdoc in EPFL (Switzerland), University of Illinois at Urbana-Champaign, and Arizona State University from 2004-2007. Since 2008, he was senior scientist and is now staff scientist in Center for functional Nanomaterials at Brookhaven National Laboratory. Up to 2015, he has co-authored >170 papers in the peer-reviewed journals with totally citation > 5000 times. More than 60 papers have been published in high impact journals (defined by DOE Basic Energy Science office). He delivered many invited lectures at the conferences or seminars in Universities, including No. 507 Brookhaven Lecture.