Berlin 2015 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

MM 10: Functional materials II: Battery Materials

MM 10.4: Vortrag

Montag, 16. März 2015, 12:30–12:45, TC 010

A Mn3O4@MWCNT composite as anode material for Li-ion batteries — •Alexander Ottmann¹, Philip Schneider¹, Elisa Thauer¹, Maik Scholz², Marcel Haft², Markus Gellesch², Franziska Hammerath², Bernd Büchner², Silke Hampel², and Rüdiger Klingeler¹ — ¹Kirchhoff-Institute for Physics, Heidelberg University, Germany — ²Leibniz Institute for Solid State and Materials Research (IFW), Dresden, Germany

Mn₃O₄ nano-sized particles have been incorporated into the inner hollow cavities of multi-walled carbon nanotubes (MWCNT) via a solution-based approach. The resulting composite material with about 40 wt% of incorporated Mn₃O₄ has been used for electrochemical half-cell studies against Li⁰/Li⁺ by means of cyclic voltammetry and galvanostatic cycling with potential limitation (GCPL). For electrode preparation, no additional carbon black has been used. Cyclic voltammetry shows well-performing working electrodes. The redox peaks during the first half-cycle indicate formation of MnO and subsequently its reversible conversion reaction to metallic Mn. This is confirmed, e.g., by our magnetic studies. In addition, the electrochemical data reveal the formation of a solid electrolyte interface (SEI) and reversible lithium de/-intercalation into the MWCNT. The GCPL data confirm complete conversion of Mn₃O₄ to MnO during the first half-cycle and full accessibility of the theoretical capacity of the MnO + 2Li⁺ + 2e⁻ <=> Li₂O + Mn conversion reaction (703 mAhg⁻¹). The composite material reaches a maximum discharge capacity of 461 mAhg⁻¹ at a current of 100 mAg⁻¹ and maintains 97 % of it in the 30^th cycle.