Electrochemical lithium intercalation in Li2Ti3O7-ramsdellite structure

Electrochemical lithium intercalation has been carried out in the Ramsdellite-type structure of Li2Ti3O7. The intercalation of 2.24 lithium ions at a very low potential in this compound leads to the formation of a new phase Li4.24Ti3O7. From powder X-ray diffraction we deduce that the structure of Li4.24Ti3O7 is closely related to the parent Ramsdellite. Both the large reversibility and the relatively high specific capacity (235 Ah Kg−1) make this compound a promising material as the negative electrode for secondary lithium cells.