Preparation of LiCoO<sub>2</sub> from Cathode Materials of Spent Lithium Ion Batteries

Abstract

Preparation of LiCoO2 cathode materials from spent lithium ion batteries are presented. The processes contain reduction, separation, precipitation, regeneration. The optimum conditions of recovery are: the calcination temperature is 500°C, the volume rate of sulfuric acid and the water reaches 0.375, the hightest leach-ing rate of cobalt is 43.53%. According to the solubility of oxalate, ammonium oxalate is choiced as precipitation agent. The investigation of X-ray diffraction (XRD), scanning electron microscopy (SEM), charge-discharge testes at voltage ranges rate from 2.8V to 4.2V versus Li , 0.2 C rate are performed. The results reveal that the regenerative LiCoO2 is pure phase, initial discharge capacity is 128.63 mAh•g-1, after 50 cycles the discharge capacity is 118.61 mAh•g-1, capacity retention rate is 92.21%. The regenerative LiCoO2 exhibits excellent electrochemical performance and stability. The materials may find promising applications in lithium ion batteries.