title: Structural and Electrochemical Study of Vanadium-Doped TiO2 Ramsdellite with Superior Lithium Storage Properties for Lithium-Ion Batteries.
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 Li0.5 Ti1-x Vx O2 (0≤x≤0.5) by a conventional solid-state reaction. The lithium-free Ti1-x Vx O2 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 Li0.5 Ti1-x Vx O2 compounds and to follow the lithium extraction by difference-Fourier maps. Previously delithiated Ti1-x Vx O2 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.
authors.affiliation: Departamento de Química y Bioquímica, Facultad de Farmacia, Universidad CEU San Pablo, 28668, Boadilla del Monte, Madrid, Spain), Fax: (+34) 913510475.
authors.forename: Juan Carlos
authors.initials: JC
authors.lastname: Pérez-Flores
authors.affiliation: Forschungsneutronenquelle Heinz Maier-Leibnitz (FRM II), Technische Universität München, Lichtenbergstr. 1, 85747, Garching, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Hoelzel
authors.affiliation: Departamento de Química y Bioquímica, Facultad de Farmacia, Universidad CEU San Pablo, 28668, Boadilla del Monte, Madrid, Spain), Fax: (+34) 913510475.
authors.forename: Flaviano
authors.initials: F
authors.lastname: García-Alvarado
authors.affiliation: Departamento de Química y Bioquímica, Facultad de Farmacia, Universidad CEU San Pablo, 28668, Boadilla del Monte, Madrid, Spain), Fax: (+34) 913510475. akuhn@ceu.es.
authors.forename: Alois
authors.identifier: http://orcid.org/0000-0002-4670-1473
authors.initials: A
authors.lastname: Kuhn
keywords: electrodes; lithium-ion batteries; oxides; ramsdellite; titanates