Regensburg 2013 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 9: Functional Materials - Battery Materials II
MM 9.4: Vortrag
Montag, 11. März 2013, 12:30–12:45, H26
Electrochemical investigation and analytical TEM on sputter deposited V2O5 thin film electrodes — •Tobias Gallasch, Frank Berkemeier, and Guido Schmitz — Institut für Materialphysik, Westfälische Wilhelms-Universität, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany
Thin film electrodes (10 nm - 200 nm) of Vanadium Pentoxide (V2O5) are prepared by ion beam sputtering. Cyclic voltammetry as well as chrono-potentiometric measurements demonstrate that the films reach the theoretical capacity for lithium storage of 400 mAh/g and that they can be operated in a wide current range (charge/discharge rates between C/44 and 77 C). Furthermore, the Li+ diffusion coefficient is determined by cyclic voltammetry and compared to results of the concentration dependent GITT technique.
In contrast to electrochemical studies on bulk material, the sputter-deposited thin films of this work provide a well-defined geometry. Therefore, fundamental processes, such as Li transport and cyclic aging can be studied in detail via analytical TEM an HR-TEM. Additionally, in this work, we are in particular studying the charge/discharge process via the EELS technique, which is sensitive on smallest changes in composition and can help to locally determine the lithium concentration within the V2O5 thin films.
Thus, we present a combination of fundamental electrochemical methods with high resolution and analytical TEM, to obtain detailed information about structural changes within the electrode material during the intercalation and deintercalation reaction.