Structural and Electrochemical Study of Vanadium‐Doped TiO2 Ramsdellite with Superior Lithium Storage Properties for Lithium‐Ion Batteries |
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| Authors: | Dr Juan Carlos Pérez‐Flores Dr Markus Hoelzel Dr Flaviano García‐Alvarado Dr Alois Kuhn |
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| Institution: | 1. Departamento de Química y Bioquímica, Facultad de Farmacia, Universidad CEU San Pablo, Boadilla del Monte, Madrid, Spain), Fax: (+34)?913510475;2. Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universit?t München, Garching, Germany |
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| Abstract: | Titanium‐oxide‐based materials are considered attractive and safe alternatives to carbonaceous anodes in Li‐ion batteries. In particular, the ramsdellite form TiO2(R) is known for its superior lithium‐storage ability as the bulk material when compared with other titanates. In this work, we prepared V‐doped lithium titanate ramsdellites with the formula Li0.5Ti1?xVxO2 (0≤x≤0.5) by a conventional solid‐state reaction. The lithium‐free Ti1?xVxO2 compounds, in which the ramsdellite framework remains virtually unaltered, are easily obtained by a simple aqueous oxidation/ion‐extraction process. Neutron powder diffraction is used to locate the Li channel site in Li0.5Ti1?xVxO2 compounds and to follow the lithium extraction by difference‐Fourier maps. Previously delithiated Ti1?xVxO2 ramsdellites are able to insert up to 0.8 Li+ per transition‐metal atom. The initial gravimetric capacities of 270 mAh g?1 with good cycle stability under constant current discharge conditions are among the highest reported for bulk TiO2‐related intercalation compounds for the threshold of one e? per formula unit. |
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| Keywords: | electrodes lithium-ion batteries oxides ramsdellite titanates |
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