Influence of heat-treatment temperature on crystal structure, morphology and electrochemical properties of LiV3O8 prepared by hydrothermal reaction

The LiV3O8 samples with different morphologies have been successfully prepared by a mixed hydrothermal-sol-solid-state route via the reaction of vanadium pentoxide(V2O5) and lithium hydrate(LiOH) at 200 degrees C in basic medium and subsequent gelation at 100 degrees C and thermal treatment at 300-550 degrees C. The crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), specific surface area measurements and scanning electron microscopy (SEM). Their electrochemical properties were investigated by means of constant charge/discharge cycling measurement. The results indicated that the calcination temperature has a significant effect on the crystal structure, morphology, and specific surface area of the LiV3O8 samples, which consequently affects their electrochemical performance such as the initial capacity and the cycleability. The sample heat-treated at 300 degrees C shows the morphology of irregular blocks with low degree of crystallinity and high specific surface area, exhibiting high initial discharge capacity of 277.7 mAh g(-1) but a fast capacity fade. In contrast, the samples annealed at higher temperature with perfectly uniform rod-like morphology show much better cycle performance. (C) 2007 Elsevier B.V. All rights reserved.