Presenter: Dr. Akihiro Kushima

Research Scientist, Department of Nuclear Science and Engineering,  Massachusetts Institute of Technology

Abstract: "Seeing is believing." In situ transmission electron microscopy (TEM) enables us to "see" dynamic processes of atomic scale phenomena in real time. For example, it is now possible to  observe  the  change  in  the  atomic  structure  of  the  Li-­‐ion  battery  electrode  materials during the charge/discharge  cycles. A single nanowire  battery was created inside TEM in the experiment,  and the change in the morphology  was recorded  as the nanowire reacted with  Li  ions.  Various  materials  were  tested  and  their  response  to  the  Li  insertion  was compared.  The  observation   provides  rich  information   of  the  reaction  mechanism  and possible solutions to improve the device performance. Li-­‐ion  battery  is  already  a  widely  commercialized  energy  storage  technology,  but  nano-­‐engineered electrodes are demonstrated to further improve the function such as, capacity, cycle-­‐lifetime,  and rate performance.  In such nano-­‐structured  electrodes, insights obtained from in situ TEM experiments can be directly linked to their performance and contribute to developing novel electrode materials. Nanotechnology is an inextricable part of our modern everyday life, and nano-­‐characterization technique such as in situ TEM is a powerful tool to understand   the  materials   from   atomic   scales   and  contribute   to  advancement   of  the technology. Atoms are small, but observing, understanding, and utilizing their behavior may lead to technological breakthroughs making huge impacts on our society.  

Bio: Dr. Akihiro Kushima is a Research Scientist in the Department of Nuclear Science and Engineering at Massachusetts Institute of Technology (MIT). His research interest is to understand the fundamental materials properties through combination of in situ electron microscopy   and   atomistic   simulations   with   particular   emphasis   on   energy   storage materials. Dr. Kushima completed his Ph.D. and undergraduate studies in the Department of Engineering Physics and Mechanics at Kyoto University, Japan in 2007. Prior to his current position,  he conducted  postdoctoral  studies  at MIT (2007-­‐2010) and University  of Pennsylvania (2010-­‐2012). He started his research career as a theorist in the field of computational  materials  science  specialized  in ab initio  quantum  mechanics  simulations. During  his  appointment  at  University  of  Pennsylvania,  he  studied  in  situ  transmission electron microscopy  (TEM) technique to understand  the atomic scale reaction mechanism of Li-­‐ion battery electrode materials under the battery operation. His research areas include Li-­‐ion/air  battery,  nano-­‐materials,  solid-­‐liquid  interfacial  reaction,  and developing  in situ TEM techniques.