Phase Evolution and Interfaces in Electrode Materials for Energy Storage

Dong Su Center for Functional Nanomaterials, Brookhaven National Laboratory and Department of Materials Science and Engineering, Stony Brook University Advanced (scanning) transmission electron microscopy ((S)TEM) techniques have been intensively applied to study the materials for energy storage.  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 resolution of nanoscale. This talk will cover my recent work on using in-situ and analytical TEM to characterize the conversion-reaction oxide material (Fe₃O₄) for electrode of lithium ion batteries(Fe₃O₄)[1-2], and Pt based nanocatalysts for fuel cell[3,4]. The dynamical process of the redox reaction of Fe₃O₄ revealed by in-situ TEM may help us to understand how reaction pathways affect the batteries’ kinetic properties. Strain coupling at interfaces is highlighted for its crucial roles in determining both the rate of electrochemical reaction and the catalytic activity. Reference: [1] Visualizing Non-Equilibrium Lithiation of Spinel Oxide via In Situ Transmission Electron Microscopy, He, et al., Nature Communications, 7,11441 (2016) [2] Strain Coupling of Conversion-type Fe₃O₄ Thin Film for Lithium Ion Battery, Hwang, et al.  Angewandte Chemie, 56,7813, (2017) [3] Biaxially strained PtPb/Pt core/shell nanoplate boosts oxygen reduction catalysis, Bu et al., Science, 354, 1410(2016) [4] Ordered Pt₃Co Intermetallic Nanoparticles Derived from Metal-organic Frameworks for Oxygen Reduction, Wang et al. Nano Lett, 18, 4163(2018)   Dr. Dong Su is currently a staff scientist in Center for Functional Nanomaterials at Bookhaven National Laboratory and an adjunct professor in the Department of Materials Science and Engineering at Stony Brook University.  He got his B.S. in 1998 from Nanjing university. He got his Ph.D  in condensed matter physics in 2003, from Nanjing university and Institute of Physics, CAS (advisors: Prof. Yening Wang, and Prof. Kehsin Kuo).  After doing postdoc in EPFL, Switzerland, University of Illinois at Urbana-Champaign, and Arizona State University, he joined Brookhaven National Laboratory in 2008 as an assistant scientist. He has been through the rank and was promoted to scientist with continuing appointment in 2015.   Dr. Dong Su has published more than 290 papers in peer-reviewed journals with citation >15,000(Google). His work have been highlighted multiple times in Department of Energy(DOE) website, including one of the 40 research milestones in DOE 40^th anniversary. He has been a reviewer for DOE, NSF, and ACS grants and journals of Nature, Nature Materials, Nature Communications, Science Advances, PRL, JACS, etc, an organizer of symposium in national conferences and workshops. He has given more than 30 invited talks in international conference and university seminars.