MSE Seminar Series: Azzam Mansour
Friday, April 26, 2013
1:00 p.m.-2:00 p.m.
Room 2110 Chemical and Nuclear Engineering Bldg.
Spectroscopic Investigations of Energy Storage and Conversion Materials
Naval Surface Warfare Center, Carderock Division
Materials and Power Systems Branch
Energy storage and conversion devices are essential from the standpoint of reducing our dependence on foreign oil. Due to their high energy and power densities, lithium-ion batteries are being considered for large scale applications such as in electric vehicles. However, for wide spread applications, lower cost, safer and even higher energy and power density materials are being sought for next generation batteries. We have used X-ray absorption spectroscopy (XAS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) to develop fundamental understanding of (1) the effects of synthesis conditions on the electronic and atomic structure of lithiated transition metal oxides, (2) processes associated with the interfacial instability between active material and electrolyte and (3) relationships between structure and electrochemical performance parameters. Our efforts have focused on investigating the surface chemistry of "AlPO4" coated LiCoO2 as well as low-cost and high capacity LiNi0.5Mn0.5O2 cathode material. In another effort, we have examined the effect of Si substitution on the electronic and local atomic structure of Ga and Ge in thermoelectric (TE) Ba6Ga16Ge30 type I clathrates. In recent studies, Si substitution for Ge in thermoelectric Ba8Ga16Ge30, at the appropriate level, has been shown to improve the thermal to electrical conversion efficiency. Variations in the density of electronic states and local coordination geometry for Ga and Ge as a function of Si content and their influence on TE properties will be presented.
About the Speaker
Dr. Mansour is a member of the Materials and Power Systems Branch of the Carderock Division of the Naval Surface Warfare Center, West Bethesda, MD. Dr. Mansour received his Ph.D. from the Departmental of Physics at North Carolina State University in 1983. Dr. Mansour has extensive experience with applications of synchrotron based X-ray absorption spectroscopy (XAS) and X-ray Photoelectron Spectroscopy (XPS) to a wide range of materials (e.g., electrochemical power sources, thermoelectrics, catalysis, coatings, and nanotechnology). Dr. Mansour co-authored over 90 journal refereed articles, over 45 conference proceedings and over 150 technical presentations and 3-patents. Dr. Mansour is a member of the American Physical Society (APS) and the Electrochemical Society (ECS).