TITLE: "Characterization of lithium battery materials"

SPEAKER: Professor Guy Ouvrard,^*

TIME: Thursday Oct. 28, 2004 at 4 PM

PLACE: George P. Williams, Jr. Lecture Hall, (Olin 101)

^*Visit sponsored jointly with the Department of Chemistry

Lithium batteries play an increasing role in energy storage. Even with the commercial adoption of lithium-ion batteries, an intense effort is needed to improve existing systems and to develop new ones such as lithium-polymer batteries. A large part of the research effort is devoted to developing a better understanding of the electrode materials. During the battery cycling, corresponding to lithium insertion and deinsertion, these materials experience structural changes and charge transfer processes. In parallel to electrochemical characterization, these changes can be studied by different techniques: X-ray and neutron diffraction, X-ray absorption spectroscopy (XAS), X-ray photoelectron spectroscopy (XPS), NMR, Mössbauer, etc. Band structure calculations have proven to be a more precise way of characterizing the charge transfer process.

In this presentation, after a general view of the lithium batteries and the objectives of the present research in this field, some examples will be shown. We will demonstrate how XAS is important to analyze the structural changes in some negative electrodes. We will also show how the charge transfer process in positive and negative electrodes can be precisely determined by an appropriate combination of band structure calculations and various spectroscopies (XAS, EELS and XPS).

100 Olin Physical Laboratory, 7507 Reynolda Station Wake Forest University Winston-Salem, NC 27109-7507 Phone: (336) 758-5337, FAX: (336) 758-6142 E-mail: wfuphys@wfu.edu	Quick Links Academics Research People Colloquia Info Physics