For NYSS APS information, contact:
Bruce White

Phase Evolution and Interfaces in Nanomaterials for Energy Storage

Dong Su

Center for Functional Nanomaterials, Brookhaven National Laboratory and
Department of Materials Science and Engineering, Stony Brook University

For energy-related materials, the understanding of property-structure relationship is based on the knowledge of their structure, interfaces and phase evolution. Advanced (scanning) transmission electron microscopy ((S)TEM) techniques have been applied to investigate the structure as well as their functions of the energy-related materials, with the help of combined electrochemical and theoretical approaches. In the first part of this talk, I will discuss my recent work on TEM characterization of the conversion oxide compounds for lithium/sodium ion batteries.  While our ex situ TEM study reveal the structural change in the real cell probe local structural and chemical information at a spatial resolution of nanoscale., in situ TEM study can help us to understand the process of lithiation/sodiation. In the cases of rocksalt-structure oxide(NiO)[1-2] and spinel oxides(Fe3O4 and Co3O4)[3-4] compounds, we have investigated the dynamical process of the redox reaction in real time. The role of reaction pathways is highlighted which is supposed to affect the batteries' kinetic properties. In the second part of the talk, I will discuss the strain coupling of highly uniform PtPb/Pt core/shell nanoplates [5], which may help to optimize the Pt-O bond strength and therefore boost their activity and stability for oxygen reduction reaction (ORR).

[1] Transitions from Near-Surface to Interior Redox upon Lithiation in Conversion Electrode Materials, Kai He, et. al, Nano Letters, 15, 1444, (2015)

[2] Sodiation Kinetics of Metal Oxide Conversion Electrodes: a Comparative Study with Lithiation, Kai He, et. al, Nano Letters, 15, 5755, (2015)

[3] Visualizing Non-Equilibrium Lithiation of Spinel Oxide via In Situ Transmission Electron Microscopy, Kai He, et al., Nature Communications, 7:11441 doi: 10.1038/ncomms11441, (2016)

[4] Kinetic Phase Evolution of Spinel Cobalt Oxide during Lithiation, Jing Li, et al., ACS Nano,  10, 9577-9585, (2016)

[5] Biaxially strained PtPb/Pt core/shell nanoplate boosts oxygen reduction catalysis, Bu et al., Science, 354, 1410-1414(2016)

For program, contact one of the organizers: For local information, contact:
Dr. Hao Zeng – haozeng@buffalo.edu
Dr. Peihong Zhang – pzhang3@buffalo.edu
Dr. Uttam Singisetti - uttamsin@buffalo.edu
Ms. Tracy Gasinsky - tracygas@buffalo.edu
Phone: 716-645-3629
Department of Physics, Buffalo, NY