Structural and electrical studies of LiMnVO4 cathode material for rechargeable lithium batteries

Abstract

The lithium manganese vanadate (LiMnVO4) cathode material was synthesized by using sol–gel method. The thermal behavior of the material has been examined by thermogravimetric and differential thermal analysis. The structure of LiMnVO4 compound was studied by the Rietveld refined X-ray diffraction technique. Raman spectra showed that the local environment including VO4 tetrahedra and LiO6 octahedra as vibrational local units. X-ray photoelectron spectroscopy studies of synthesized LiMnVO4 powder indicate that the oxidation states of manganese and vanadate are +2 and +5, respectively. The ionic conductivity of the sample is found to be 2.7 × 10−5 Scm−1 at 300 °C. The temperature dependent conductivity was conformed from the Arrhenius relation and the activation energy is found to be 0.3 eV. Dielectric spectra showed the decrease in dielectric constant with increase in frequency. Dielectric loss spectra reveal that dc conduction contribution predominates in the compound.