Preparation of TiO2-coated LiCo1/3Ni1/3Mn1/3O2 by electrostatic self-assembly method and its properties

A precursor of TiO2-LiCo1/3Ni1/3Mn1/3O2 was prepared by electrostatic self-assembly method. The final product was obtained by heating the precursor at 400-450 degrees C for 4-6 h in air. X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical tests were used to examine the structural, morphology, elementary valence, and electrochemical characteristics. XRD indicated that the TiO2-coated material can be indexed by alpha-NaFeO2 layered structure, which belongs to hexagonal-type space group R3m. XPS results confirmed the existence of TiO2 compound on the surface of the coated sample. The SEM image showed that the material had spherically porous morphology with the uniform size about 6 mu m. The initial charge-discharge capacity of the TiO2-coated LiCo1/3Ni1/3Mn1/3O2 material was 168.8/160.0 mAh/g. After 60 cycles, the discharge capacity of the TiO2-coated LiCo1/3Ni1/3Mn1/3O2 sample was 147.0 mAh/g, and the coulombic efficiency was 94.0%. Compared with the uncoated sample, the electrochemical performance of TiO2-coated LiCo1/3Ni1/3Mn1/3O2 was improved.