PREPARATION AND ELECTROCHEMICAL CHARACTERISTICS OF NEW MNO2-V2O5 SYSTEMS AS POSITIVE MATERIALS FOR RECHARGEABLE LITHIUM BATTERIES

New binary oxides, MnO2.xV2O5 (x = 0-0.3), which were formed by heating mixtures of Mn(NO3)2.6H2O and NH4VO3 at various V/Mn atomic ratios and at different temperatures in air, have been characterized by X-ray diffraction method, X-ray photoelectron spectroscopy and infrared spectroscopy. The amount of Li+ ions inserted into the crystal lattice of the oxide increased with increasing x-value in MnO2.xV2O5, and reached ca 1 Li/mole of the oxide with x = 0.6. Furthermore, the thermodynamic and kinetic studies showed that the standard free energy for the lithium insertion, DELTA-G1, is -265 kJ mol-1 in the range of n = 0-1 in LinMnO2.xV2O5 at 25-degrees-C and that the chemical diffusion coefficients of lithium in the oxide matrices are in the range from 10(-9) to 10(-12) cm2 s-1 at 25-degrees-C and increased with increasing V2O5 content in the mixed oxides.