Electrochemical Performance of Cathode LiVOPO4 Doped with Mo and W

Molybdenum (Mo) and tungsten (W) substituted LiV0.99X0.01OPO4 (X = Mo and W) compounds were synthesized by impregnation method. The structures of samples were characterized by X-ray diffraction, and their electrochemical properties were studied by using charge-discharge in galavanostatic mode versus Li+/Li. The electrical conductivity of the samples was estimated by using impedance spectroscopy measurement with 2 point probe method at room temperature. Phosphates of composition LiV0.99X0.01OPO4 with 1% Mo and W content in the structure exhibits high intercalation potential of 3.95 V versus Li/Li+. It was found that the electrical conductivity of Mo and W substituted samples at room temperature was improved to 4.8. x 10(-6) and 1.5 x 10(-5) S.cm(-1), respectively. Discharge capacity was also observed for the W doped sample with good retention performance up to 20 cycles at high current density of C/5 (0.4 mA.cm(-2)).