Regensburg 2013 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 15: Poster Session

MM 15.31: Poster

Montag, 11. März 2013, 18:00–20:00, Poster E

High-Performance LFP Thin Film Electrodes — •Frank Berkemeier, Mathias Köhler, Lea Lüken, and Guido Schmitz — Universität Münster, Institut für Materialphysik, Wilhelm-Klemm Str. 10, D-48149 Münster

Thin films of lithium iron phosphate (LFP) are prepared by reactive ion beam sputtering, with a thickness between 50 and 500 nm. The structure and morphology of the layers is investigated by X-ray diffraction measurements and transmission electron microscopy, while their electrochemical properties are characterized by means of cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and the galvanostatic intermittent titration technique (GITT). It is observed that the electrochemical performance of the layers strongly depends on the preparation conditions during sputtering. Thus, using optimum deposition conditions, a reversible capacity of 104 mAh g⁻¹ is found, and a cycling stability at 1 C rate which allows to perform more than 1700 cycles before observing a capacity loss of only 20%. In addition, the lithium diffusivity is measured by EIS and GITT, and is found to be in the range of 10⁻¹³ cm²s⁻¹. This quite high diffusivity value is attributed to the strong texture of the deposited LFP films.