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 LiCoO ₂ 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.