Phase transition in the spinel Li4Ti5O12 induced by lithium insertion
2003; Elsevier BV; Volume: 119-121; Linguagem: Inglês
10.1016/s0378-7753(03)00186-1
ISSN1873-2755
AutoresPierre Kubiak, Aurélie Garcia, M. Womes, Laurent Aldon, J. Olivier‐Fourcade, Pierre‐Emmanuel Lippens, J.‐C. Jumas,
Tópico(s)Advanced Condensed Matter Physics
ResumoThe spinel Li4Ti5O12, a stable phase of the Li2O–TiO2 system, allows to insert three Li atoms per formula unit at a potential of 1.5 V on the basis of a spinel ↔ NaCl phase transition. This mechanism leads to a reduction of three Ti(IV) atoms out of five, corresponding to a theoretical capacity of 175 mAh/g. The influence of structural defaults on the spinel → NaCl phase transition and its reversibility during charge/discharge cycles have been studied. Solid solutions formed from chemical insertion of lithium or substitutions Ti/V, Ti/Mn, Ti/Fe modify the cation distribution on the crystallographic sites (tetrahedral 8a, octahedral 16d, space group Fd3m) and influence the electrochemical performances. A structural analysis by X-ray and neutron diffraction, X-ray absorption, 57Fe Mössbauer spectroscopy and first principle calculations have allowed to establish a relationship between the structure and the electrochemical properties.
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