Preparation and Electrochemical Properties of LiNi1/3Co1/3- Mn1/3O2/C Composite Cathode Materials for Lithium-Ion Battery

Layered LiNi1/3Co1/3Mn1/3O2 was synthesized by a co-precipitation method, and a series of LiNi1/3Co1/3Mn1/3O2/C composites were prepared by Citric acid (CA) on the surface of LiNi1/3Co1/3Mn1/3O2. The bare sample and the composites were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The electrochemical properties of the composites were investigated with a galvanostatic charge-discharge test and AC impedance techniques. XRD measurements show that the carbon coating does not alter the crystal structure of the LiNi1/3Co1/3Mn1/3O2. The 5.0wt% C-coated LiNi1/3Co1/3Mn1/3O2 exhibits a good electrochemical performance, whose first discharge capacity is 174.2 mAh/g at 0.1 C rate and in the voltage range of 2.8 similar to 4.6V, much higher than 156.7 mAh/g of the bare sample.