Hybrid microwave synthesis and characterization of the compounds in the Li-Ti-O system

Hybrid microwave synthesis has been applied for preparation of Li4Ti5O12, Li2Ti3O7, LiTiO3 and LiTiO2 for the first time. Stepwise heating was used for avoiding the instantaneous release of gas by-product and obtaining well-shaped samples. The samples were characterized by powder X-ray diffraction, energy-dispersive X-ray analysis and scanning electron microscopy. The obtained samples have relatively uniform particle sizes. The electrochemical performance of Li4Ti5O12 and Li2Ti3O7 were investigated. The first discharge capacity of Li4Ti5O12 was 150 mAh g(-1) and 141 mAh g(-1) after 27 cycles and a very flat discharge and charge curve of Li4Ti5O12 was shown at about 1.56 V. Similarly, Li2Ti3O7 exhibits good cycle performance. The initial discharge capacity is 118 mAh g(-1) and 30th cycle is still 112 mAh g-1. (C) 2007 Elsevier B.V. All rights reserved.