A novel carbon-coated LiCoO₂ as cathode material for lithium ion battery

Using a commercially available LiCoO₂ as starting material, a surface-modified cathode material was obtained by coating it with a nano layer of amorphous carbon. The carbon-coated LiCoO₂ was characterized by X-ray diffraction analysis, scanning electronic microscopy, transmission electronic microscopy, electrochemical impedance spectroscopy and measurement of charge/discharge behavior. Results show that the carbon-coated LiCoO₂ displays marked lower charge transfer resistance, higher lithium ion diffusion coefficient and much better rate capability than the original LiCoO₂. It also indicates promising application of lithium ion batteries in the areas requiring charge and discharge at high rate.