Title Existence of superstructures due to large amounts of Fe vacancies in the $LiFePO_{4}$-type frameworkExistence of superstructures due to large amounts of Fe vacancies in the $LiFePO_{4}$-type framework Author Hamelet, S. Casas-Cabanas, M. Dupont, L. Davoisne, C. Tarascon, J. M. Masquelier, C. Faculty/Department Faculty of Sciences. Physics Research group Electron microscopy for materials research (EMAT) Publication type article Publication 2011Washington, D.C., 2011 Subject Physics Chemistry Source (journal) Chemistry of materials / American Chemical Society. - Washington, D.C. Volume/pages 23(2011):1, p. 32-38 ISSN 0897-4756 ISI 000285726900007 Carrier E Target language English (eng) Full text (Publishers DOI) Affiliation University of Antwerp Abstract LiFePO4 has been under intense scrutiny over the past decade because it stands as an attractive positive electrode material for the next generation of Li-ion batteries to power electric vehicles and hybrid electric vehicles, hence the importance of its thermal behavior. The reactivity of LiFePO4 with air at moderate temperatures is shown to be dependent on its particle size. For nanosized materials, a progressive displacement of Fe from the core structure leading to a composite made of nanosize Fe2O3 and highly defective, oxidized LixFeyPO4 compositions, among which the "ideal" formula LiFe2/3PO4. Herein we report, from both temperature-controlled X-ray diffraction and electronic diffraction microscopy, that these off-stoichiometry olivine-type compounds show a defect ordering resulting in the formation of a superstructure. Such a finding shows striking similarities with the temperature-driven oxidation of fayalite Fe2SiO4 (another olivine) to structurally defective laihunite, reported in the literature three decades ago. E-info http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000285726900007&DestLinkType=RelatedRecords&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000285726900007&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000285726900007&DestLinkType=CitingArticles&DestApp=ALL_WOS&UsrCustomerID=ef845e08c439e550330acc77c7d2d848 Handle