The re-synthesis of LiCoO₂ from spent lithium ion batteries separated by vacuum-assisted heat-treating method

The LiCoO₂ is re-synthesized from spent lithium ion batteries by a simple process combined with vacuum-assisted heat-treating and solid state reaction at 750°C. The batteries can be fully discharged in 1wt.% NaCl solution without the leakage of case. The results show that the product after two times of heat-treatment mainly contains of Co₃O₄. The re-synthesized LiCoO₂ shows a reversible capacity of 106.8 mAh g^-1 and almost no capacity degradation after 20 charge/discharge cycles. The relative low reversible capacity is ascribed to the large particle size of the raw material Co₃O₄, which can be optimized by adjusting the ball-milling parameters to ensure the fully mixture of the Co₃O₄ and Li₂CO₃.