Synthesis of Co_3(OH)_2V_2O_7·1.7H_2O nanosheets and its application in lithium ion batteries

摘要

Cobalt vanadium oxide hydroxide hydrate (Co_3(OH)_2V_2O_7·nH_2O) nanosheets are successfully synthesized by a simple hydrothermal method. The composition of Co_3(OH)_2V_2O_7·nH_2O is studied by thermal gravity (TG) analysis in N_2 atmosphere and subsequent X-ray powder diffraction (XRD) characterization of the sample obtained via annealing Co_3(OH)_2V_2O_7·nH_2O nanosheets in N_2 atmosphere at 800 ℃ for 6h. The results indicate that there are 1.7 water molecules in a Co_3(OH)_2V_2O_7·-nH_2O molecular formula. Electrochemical properties of Co_3(OH)_2V_2O_7·1.7H_2O nanosheets as negative electrode of lithium ion batteries are studied by conventional charge/discharge test, which show an initial capacity of 730 mAh g~(-1) with steady plateau near 0.9 V at a current density of 0.05 mA cm ~(-2).