Structural, XPS and impedance analysis of LixCoVO4 (x = 0.8, 1.0, 1.2)

Lithium cobalt vanadate LixCoVO4 (x = 0.8; 1.0; 1.2) has been prepared by a solid state reaction method. The XRD analysis confirms the formation of the sample. A new peak has been observed for Li1.0CoVO4 and for Li1.2CoVO4 indicating the formation of a new phase. The XPS analysis indicates the reduction in the oxidation of vanadium and oxygen with the addition of Li in LixCoVO4 (x = 0.8, 1.0, 1.2). The impedance analysis gives the conductivity value as 2.46 × 10− 5, 6.16 × 10− 5, 9 × 10− 5 Ω− 1 cm− 1 for LixCoVO4 (x = 0.8; 1.0; 1.2), all at 623 K. The similarity in the bulk activation energy (Ea) and the activation enthalpy for migration of ions (Eω) indicate that the conduction in Li1.2CoVO4 has been due to hopping mechanism.