Recovery of LiCoO2 and graphite from spent lithium-ion batteries by molten-salt electrolysis

The recovery of spent lithium-ion batteries has not only economic value but also ecological benefits. In this paper, molten-salt electrolysis was employed to recover spent LiCoO₂ batteries, in which NaCl-Na₂CO₃ melts were used as the electrolyte, the graphite rod and the mixtures of the spent LiCoO₂ cathode and anode were used as the anode and cathode, respectively. During the electrolysis, the LiCoO₂ was electrochemically reduced to Co, and Li⁺ and O^2- entered into the molten salt. The O^2- was discharged at the anode to generate CO₂ and formed Li₂CO₃. After electrolysis, the cathodic products were separated by magnetic separation to obtain Co and graphite, and Li₂CO₃ was recovered by water leaching. The recovery efficiencies of Li, Co, and graphite reached 99.3%, 98.1%, and 83.6%, respectively. Overall, this paper provides a simple and efficient electrochemical method for the simultaneous recovery of the cathode and the anode of spent LiCoO₂ batteries.