Rhombohedral-structured LiVO2 prepared by a novel two-step method and its electrochemical properties

Abstract

Layered LiVO2 was prepared as a cathode material for lithium ion batteries by a novel two-step reduction method. The structure and morphology of the material were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The specific capacity of the material reached 201.7 mAh g-1 when charged and discharged at a rate of 0.2 C in the voltage range of 1.0-4.5 V. The retention ratio of discharge capacity was 65% after 30 cycles. The charge-transfer resistance calculated by fitting the experimental electrochemical impedance data to the equivalent circuit model was 81.65 O. From this, the lithium ion diffusion coefficient was calculated to be 2.72×10-11 cm s-1, indicating that this material exhibits excellent ionic and electronic conductivity.