On the synthesis conditions for tailoring lithium composition in ramsdellite phases: Application for Li-ion batteries

TiO2 with the ramsdelitte-type (R) structure has a potential use as negative electrode for Li-ion battery due to its high theoretical capacity (335 mAh g(-1)), a weak irreversible loss during the first cycle and a low polarization. However due to its metastability, TiO2 (R) has been rarely reported. In the present work we report on the carbothermal synthesis of some LixTiO2 delithiated R phases (0 < x < 0.57), from TiO2 to Li2Ti3O7, with ramsdellite-type structure. The variation of the synthesis parameters such as wt% of carbonaceous additive and reductive gas flow has conducted to the formation of poor lithiated LixTiO2 phases and Li2TiO3 as additional phase. Their ratio was found to be strongly dependent on the amount of car_bonaceous precursor. These new LixTiO2(R)/Li2TiO3 composites (with (0 <= x <= 0.57)) were characterized by chemical analysis, X-ray diffraction and thermogravimetric analysis and finally by electrochemical tests. High capacities as well as good cycleability have been reached. (C) 2012 Elsevier B.V. All rights reserved.