Preparation and electrochemical properties of re-synthesized LiCoO₂ from spent lithium-ion batteries

A new idea for reuse of the cathode materials of lithium-ion batteries (LIBs) is investigated to develop an environmentally friendly process for recycling spent batteries. LiCoO₂ is re-synthesized from spent LIBs by leaching and a sol-gel method calcined at high temperature. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) are employed to study the reactions occurring calcination that are responsible for the weight losses. X-ray diffraction (XRD) and scanning electron microscopy (SEM) are used to determine the structures of the LiCoO₂ powders. It was found that a pure phase of LiCoO₂ can be obtained by the re-synthesis process. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) are used to evaluate the electrochemical properties of the LiCoO₂ powders. The discharge capacity of re-synthesized LiCoO₂ is 137 mAh g^-1 at the 0. 1 C rate, and the capacity retention of the re-synthesized LiCoO₂ is 97. 98% after 20 cycles at the 0. 1 C rate, and 88. 14% after 40 cycles. The results indicate that the re-synthesized LiCoO₂ displays good charge/discharge performance and cycling behavior.