报告人: Teng Li  Associate Professor

Department of Mechanical Engineering,Maryland NanoCenter

University of Maryland Energy Research Center

University of Maryland, College Park, Maryland, USA

 

Advanced energy storage technology is a crucial component in integrating renewable energy sources, whose success holds promise to revolutionize facets of our daily life through high performance batteries for personal devices and electric cars. Development of next-generation high performance batteries relies on the new choice of electrode materials and structures. For example, silicon anode can provide the highest theoretical charging capacity for lithium-ion battery, more than 10 times

higher than widely used carbon anodes. However, significant challenge exists before the success application of silicon-based anodes for lithium-ion battery. During operation cycling, the insertion and extraction of Li ions lead to a volume change up to 400% in charged silicon anodes. Such a huge volume change results in substantial stress in the anodes, which in turn causes the anode pulverization and eventually leads to capacity fading and failure of the battery. Similar challenge exists in designing high performance electrode in sodium-ion battery for grid-scale energy storage technology. Recent studies reveal that novel nanostructure designs of anodes can allow the anodes to accommodate the huge volume change during charging/discharging cycling without fracture. To this end, our research aims to shed light on the fundamental understanding of stress generation and failure mechanisms of such nanostructured electrodes in high-performance batteries. In this talk, I will discuss three novel designs of nanostructured anodes: 1) beaded silicon on a carbon nanotube string as anodes for lithium-ion batteries, 2) tin film coated on a natural wood nanofiber as anodes in sodium-ion batteries for low-cost and green grid-scale energy storage and 3) tin nanoparticles coated with oxide nano-glue as anodes in sodium-ion batteries.

 

Teng Li received his Ph.D. degree in Engineering Science from Harvard University in 2006, after earlier study in Princeton University and Tsinghua University in China. He is currently an Associate Professor of Mechanical Engineering and the Keystone Professor in the Clark School of Engineering at the University of Maryland, College Park, US. He is also an affiliated faculty of Maryland NanoCenter and University of Maryland Energy Research Center. His research interests include mechanics of flexible electronics and nanoelectronics, mechanics of low dimensional carbon nanomaterials, and mechanics of energy systems. Among his awards includes US National Committee of Theoretical and Applied Mechanics Fellowship in 2012, E. Robert Kent Outstanding Teaching Award in 2012, University of Maryland GRB Research Award in 2009 and RASA Research Award in 2014, Ralph E. Powe Jr. Faculty Award in 2007. He has been a member of the Technical Committee of Integrated Structures in ASME Applied Mechanics Division since 2006 and served as the Chair of the Committee during 2008-2012. He currently serves as the Associate Editor of Extreme Mechanics Letters and a member of the Editorial Board of International Journal of Computational Materials Science and Engineering. He is the co-founder (with Zhigang Suo) of iMechanica.org, the world’s largest online community of mechanics with 60,000+ registered users as of June 2014.