Preparation of LiCoO2 films from spent lithium-ion batteries by a combined recycling process

A new process is described for recovering and regenerating lithium cobalt oxide from spent lithium-ion batteries (LIBs) by a combination of dismantling, detachment with N-methylpyrrolidone (NMP), acid leaching and re-synthesis of LiCoO2 from the leach liquor as a cathode active material. The leach liquor, obtained from spent LIBs by using a nitric acid leaching solution, is used as electrolyte to regenerate LiCoO2 crystals on nickel plate at constant current in a single synthetic step using electrochemical deposition technology. The crystal structure and surface morphology of regenerated LiCoO2 were determined by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. LiCoO2 phase with preferred (104) orientation was electro-deposited on nickel substrate at current density 1 mA cm− 2 for 20 h, and found to have good characteristics as a cathode active material in terms of charge and discharge capacity, and cycling performance. The particle size and layer thickness of the regenerated LiCoO2 crystalline powder were 0.5 μm and 0.2 mm, respectively. The initial charge and discharge capacity were 130.8 and 127.2 mAh g− 1, respectively. After 30 cycles, the capacity had decreased by less than 4% compared with the first cycle. This process involves simple equipment and could be feasible for recycling LIBs in large scale.