Cobalt recovery from spent Li-ion batteries using lactic acid as dissolution agent

Abstract

The effective recovery of cobalt from spent cathode materials is a critical issue and becomes a necessary assignment for the waste treatment of spent lithium-ion batteries (LIBs) in concern with waste to wealth. The dissolution process encompasses an organic acid leaching followed by recovery of pure Co oxalate. The use of lactic acid effectively improves the leaching of spent LiCoO2 materials with ascorbic acid. The leaching efficiencies of 99% for Li and 98% for Co were achieved under the optimal condition of 0.5 mol/L lactic acid and 0.02 mol/L ascorbic acid, solid/liquid ratio of 2 g/L, leaching time of 360 min and temperature of 90 °C. Based on the kinetic analysis, the enhancement leaching process is mainly on the concentration of dissolution reagent. Compared to other organic acids used previously, lactic acid showed better dissolution behavior.

Keywords

• Spent Li-ion batteries
• Cathode recycling
• Lactic acid
• Kinetic analysis