Structural and electrochemical characteristics of Li-4/Ti-3(5)/O-3(4) as an anode material for rechargeable lithium batteries

Li4/3Ti5/3O4 is a good anode material for rechargeable lithium batteries. T his material exhibits characteristic properties, including very flat discha rge and charge curves and an infinitesimal structural change during dischar ge and charge. In this study the structural behaviour was confirmed by the Rietveld analysis of X-ray diffraction patterns: in situ UV-visible spectro scopy of Li4/3Ti5/3O4 during discharge was also performed to observe the el ectronic structure change induced by lithium insertion. The Rietveld analys is clearly showed that no structural change could be detected during the li thium insertion and extraction processes. The UV-vis. spectroscopy revealed that the insertion of lithium into Li4/3Ti5/3O4 results in the formation o f a new phase with the same lattice constant. These results indicate that t he insertion and extraction of lithium into and from Li4/3Ti5/3O4 proceed v ia two-phase reactions, while the lattice parameter is the same as that of Li4/3Ti5/3O4 with lithium insertion.