Regensburg 2016 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 61: Functional materials IV: Batteries III
MM 61.4: Talk
Thursday, March 10, 2016, 16:30–16:45, H52
LiMn2O4 as a thin-film battery electrode material — •Juliane Mürter, Susann Nowak, and Guido Schmitz — Institute of Materials Science, University of Stuttgart, Heisenbergstr. 3, 70569 Stuttgart, Germany
LiMn2O4 is a highly investigated cathode material for Li-ion batteries due to its low cost, low toxicity, and high voltage of over 4 V vs. Li. In this study, the material is deposited by ion-beam sputtering, with thicknesses ranging from 55 nm to 300 nm. Different post-deposition treatments are performed and the influence on capacity, cycle stability, and rate capability is studied. Excellent cycling stability over 500 cycles with almost no loss in capacity is achieved. X-ray diffraction (XRD) is used to determine the crystal structure. The electrochemical performance is investigated using chronopotentiometry (CP) as well as cyclic voltametry (CV).
Owing to the thin film geometry, the CV scan rate can be varied over 5 orders of magnitude presenting a consistent variation of peak current and overpotential. Using this data, experimental values are compared to kinetic models to determine the Li diffusion coefficient and the transfer coefficient through the surface.