Citrate-gel-combustion synthesis of LiCoVO4 as novel high-voltage cathode material for Li-ion batteries

A new method by combining Chimie Douce method with sol-gel route and using citrate as complex reagent was introduced for preparing inverse spinel LiCoVO4 as novel high-voltage cathode material for Li-ion batteries. Investigations were conducted by XRD, DSC, TG, IR, Raman, SEM, EDAX and electrochemical techniques. The results of XRD and thermal analysis show that the high crystalline LiCoVO4 with high phase purity are formed at 450°C. The results of IR and Raman show the band located at up to 820 cm-1 corresponding to the stretching vibration mode with the A1 symmetry, whereas the band situated at up to 335 cm-1 corresponding to the bending mode of the VO4 tetrahedron with E symmetry. The SEM and EDAX results show that the average diameter of the original particles is 300 nm and the distributions of particle diameter and elements are even. Electrochemical measurement shows that the initial charge capacity is l60 mAh&middotg-1 with the platform voltage of 4.8 V and its discharge capacity is 152 mAh&middotg-1.