A new form of vanadium oxide for use as a cathode material in lithium batteries

A new form of vanadium oxide, (Na2O)(0.23)V2O5, is synthesised by precipitation of sol and removing water. Its performance as a cathode material is studied by chronopotentiometry and cyclic voltammetry. A capacity 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 satisfactory in comparison with other forms of vanadium oxide and synthesis is relatively easy. X-ray diffraction (XRD) studies show that (Na2O)(0.23)V2O5 is quasi-tetragonal crystal after heating at a temperature below 250 degrees C. The crystallites of (Na2O)(0.23)V2O5 are in platelet form, and their dimensions are less than 2 mu m. Thermogravimetric analysis (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.