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MM: Fachverband Metall- und Materialphysik

MM 26: Poster Session

MM 26.33: Poster

Dienstag, 23. März 2010, 14:45–16:30, Poster C

Structural and electrochemical properties of mixed transition metal phospho-olivine systems — •Michaela Memm, Peter Axmann, and Margret Wohlfahrt-Mehrens — Zentrum für Sonnenenergie- und Wasserstoff-Forschung Helmholtzstraße 8 89081 Ulm

lithium iron phosphate LiFePO4 shows a very good cycling stability at a potential of 3.5 V vs. Li/Li+ with a specific capacity of up to 160 mAh/g at room temperature. the potential and other properties of the phospho-olivines can be influenced by substituting other transition metals, such as manganese, cobalt and nickel, for iron. the transition metal phospho olivines can form solid solutions, among which LiFexMn1-xPO4 is a well known system. In this work, we prepared and characterized binary and ternary series of phospho olivines with M = Co, Mn, Fe, Mg. the systems form solid solution series LiCo1-xMxPO4 for M = Fe, Co and LiMgxFeyMn1-x-yPO4. The particle morphology is strongly influenced by M. A two step potential characteristic is observed for the mixed systems LiCo1-xMxPO4 and LiMgxFeyMn1-x-yPO4 with the single steps occurring on potential close to those of the pure end members. Significant potential shifts can be observed depending on the composition. We found high capacity yields for the Mg containing samples