A NEW FORM OF VANADIUM-OXIDE FOR USE AS A CATHODE MATERIAL IN LITHIUMBATTERIES

A new form of vanadium oxide, (Na2O)(0.23)V2O5, is synthesised by prec ipitation of sol and removing water. Its performance as a cathode mate rial is studied by chronopotentiometry and cyclic voltammetry. A capac ity of more than 220 mA h g(-1) can be obtained in 12 cycles when the voltage is from 3.8 to 1.8 V. Its capacity and cyclability are satisfa ctory in comparison with other forms of vanadium oxide and synthesis i s relatively easy. X-ray diffraction (XRD) studies show that (Na2O)(0. 23)V2O5 is quasi-tetragonal crystal after heating at a temperature bel ow 250 degrees C. The crystallites of (Na2O)(0.23)V2O5 are in platelet form, and their dimensions are less than 2 mu m. Thermogravimetric an alysis (TGA) and differential scanning calorimetry (DSC) studies found that the sol-precipitate, (Na2O)(0.23)V2O5. xH(2)O, can lose water at 200 degrees C. (C) 1998 Elsevier Science S.A. All rights reserved.