Lithium Intercalation into Nanocrystalline Brookite TiO[sub 2]

Lithium intercalation in phase-pure nanocrystalline brookite is demonstrated for the first time. Galvanostatic studies show that per formula unit can be intercalated into this phase in initial discharge. Ex situ X-ray diffraction studies on the electrodes at different levels of lithium intercalation show that the structure is stable toward lithium intercalation and deintercation. In the initial charge, an irreversible capacity loss is observed. However, on further cycling, the phase shows excellent cycling behavior. A reversible capacity of is observed even after 40 cycles.