Low temperature synthesis and electrochemical behavior of LiV_3O_8 cathode

摘要

LiV_3O_8 cathode has been synthesized by two simple low temperature methods without involving the melting of V_2O_5 and characterized by X-ray diffraction, scanning electron microscopy (SEM), discharge-charge measurements in lithium cells and differential scanning calorimetry (DSC). While the first method involves the heating of the components in H_2 at 500 deg C followed by in N_2 at 600 deg C, the second method involves the dispersion of the components in methanol followed by evaporating the solvent and heating at 500 deg C in N_2 atmosphere. The samples exhibit a high capacity of around 230 mAh g~(-1) at 0.5 mA cm~2 and 25 deg C in a narrow voltage range of 2-3.5 V with excellent cyclability at -30 to 60 deg C. Additionally, the samples exhibit superior safety characteristics compared to the currently used LiCoO_2 cathode as indicated by the absence of exothermic peaks (DSC) up to 450 deg C in the charged state.