Hydrothermal Synthesis and Electrochemical Performance of Al-doped VO₂(B) as Cathode Materials for Lithium-Ion Battery

摘要

Al-doped VO2(B) nanobelts have been successfully synthesized via the hydrothermal method using V2O5, C6H12O6·H2O and Al(NO3)3·9H2O as reactants. XRD, FESEM, EDS and XPS were introduced to characterize the phase, morphology, compositions and chemical state of the samples. Electrochemical properties of the samples were studied by charge/discharge tests, electrochemical impedance spectra (EIS) and cyclic voltammetry (CV). The result showed that the length and width of the nanobelts were increased significantly after doping Al3+. When the doping molar ratio of Al to V was 1/6.9, the product was flower like particles which composed of nanobelts and exhibited the best cycling performance. The initial discharge capacity was 282 mAh g?1 and maintained 202 mAh g?1 after 50 cycles at the density of 32.4 mA g?1. The retention rate of capacity was 71.6%, which was better than that of the undoped sample (61%). The enhanced electrochemical performance was attributed to its higher total conductivity and better structure stability.