Title: Synchrotron-based Soft X-ray Spectroscopy for Lithium Ion Battery Research
報告人：劉嘯嵩
時間：2013年2月26日上午10：30-11：30
地點：北京大學深圳研究生院G-205
Xiaosong Liu
Advanced Light Source, Lawrence Berkeley National Laboratory, USA
High performance new materials are essential for renewable energy research and technology. The growing global energy consumption and consequent environmental threats demand us to develop and utilize more efficient approaches to discover such materials, to explore the fundamental properties of materials, and to understand the correlation between material properties and device performances. Synchrotron-based X-ray spectroscopy is one of such incisive experimental tools. It can probe materials’ key electronic structures, which are directly related to the performance of a variety of energy conversion and storage devices such as batteries, catalysis, solar cells, and fuel cells.
In this talk, He will present their recent work on Li-ion battery, in particle for the cathode material such as LiFePO4, as an example to illustrate the capability of soft X-ray spectroscopy. By means of elemental- and orbital-sensitive X-ray absorption (XAS) and X-ray emission (XES) spectroscopies, we are able to depict both key unoccupied and occupied states in electrodes. These key energy states play a decisive role in various practical characteristics of electrodes including Li diffusion, phase transformation, and safety issue. In addition, as a composite mesoscale system, the performance of LIB is not only determined by the fundamental physical and chemical properties of the individual components, but also relies on the morphology, assembly, and heterogeneity of functional units in a battery cell. All these processes are interrelated, and evolve over multiple time and length scales during and even after cycling throughout the lifetime of a battery. Therefore, development ofin situ and in operando characterization techniques to capture these responsive, dynamic, and sequential phenomena is stringent and necessary for battery research.
