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.