题目： In-situ Characterization of Reaction Mechanisms and Degradation Processes in Energy Conversion and Storage Systems

报告人：Dr. Shen J Dillon
           Assistant Professor
           Department of Materials Science and Engineering
           University of Illinois Urbana-Champaign

时间： 2016年5月6日（周五）  下午14:00-16：00

地点： 李薰楼468室

摘要：Developing new paradigms for energy generation, storage, distribution, and utilization is amongst the most challenging problems facing this generation. Several major visions exist for sustainable energy generation and utilization, including; renewably generated and stored electricity and the conversion of green or renewable energy sources into fuels. System cost and efficiency impose major barriers on alternatives to fossil fuels for electricity generation and transportation. Key to developing energy storage and conversion systems with low cost, long cycle life, high efficiency, and high energy density is the need for fundamental insights into nanoscale processes associated with chemical and electrochemical reactions.  For example, local strain gradients due to lithium insertion can govern mechanical degradation of electrode materials, and interfacial reactions between electrodes and liquid electrolyte can drive capacity fade.  Appropriately characterizing such phenomena requires in-situ and in-operando probes with appropriate spatial and temporal resolution.  Electron microscopy provides high spatial resolution and reasonable temporal resolution, and the introduction of environmental cells enables access to a rich variety of chemical and electrochemical systems.  This talk will describe our contributions to the development of environmental electron microscopy and its application to understanding reaction and degradation processes in electrochemical energy conversion and storage systems. The presentation focuses on our contributions to characterizing local strain effects in high capacity Li-ion anode materials during cycling, deformation in low density nanostructures, and the role of interfaces in extreme environments.