Synthesis and charge-discharge characteristics of polycrystalline LiNi1-xCoxO2 (0≤x≤0.5) as a cathode material for lithium rechargeable batteries

The synthesis and electrochemical characteristics of LNi1-xCOxO2 (0less than or equal to x less than or equal to 0.5) used as the promising cathode materials for lithium rechargeable batteries were investigated. The LiNi1-xCoxO2 was prepared by a soft chemistry route in which citric acid was used as the chelating agent to make the sol-gel precursor, then was calcined in oxygen atmosphere at the calcination temperature of 800degreesC for 12 h. Polycrystalline LiNi1-xCoxO2 possesses a hexagonal lattice of the alpha-NaFeO2 type characterized by using X-ray diffraction. The discharge capacity of LiNi0.8Co0.2O2 was 169.1 mAh/g with the efficiency of 90.5% in the first cycle and 162.1 mAh/g with only 4% capacity fading in the 10(th) cycle at 0.2 C rate over a potential range of 3.0-4.2 V.