A Green Electrochemical Process to Recover Co and Li from Spent LiCoO2-Based Batteries in Molten Salts

In this paper, we developed an efficient and environment-friendly approach, the molten-salt-electrolysis (MSE), to recover lithium and cobalt from spent LiCoO2-based lithium-ion batteries (LIBs). Unlike the conventional ways that employ strong acid lixiviants and reducing agents, the spent LiCoO2 was electrochemically reduced to either CoO or Co under controlled potentials at the cathode, releasing Li2O into molten salts where the Li2O combined with CO2 generated at the carbon anode to produce Li2CO3. After electrolysis, CoO/Co and Li2CO3 were leached out from the molten salts in water, and the recovery rates of Li and Co were high up to 85% and 99%, respectively. In addition, the LiCoO2 was regenerated from the recovered CoO and Li2CO3, exhibiting excellent electrochemical performances as a cathode in a LIB. Overall, the MSE route employs electrons as the reducing agent and molten salt as a solvent to recycle spent LIBs, which could be a simple, comprehensive, and green process for recycling various cathode materials.