Towards a More Sustainable Leaching Process for Li-Ion Battery Cathode Material Recycling: Mechanochemical Leaching of LiCoO2 Using Citric Acid

Abstract

Lithium-ion batteries (LIBs) require critical resources for cathode active materials production, including elements such as cobalt, nickel, and lithium. Therefore, their recycling from spent LIBs is a priority for European countries. Current recycling technologies mainly consist of hydrometallurgical processes that require large amounts of inorganic acids, reducing agents, and other chemicals for a selective recovery. In the present paper, an innovative and efficient process of Li and Co leaching from LiCoO₂ (LCO) cathode materials, which allows reducing the consumption of chemicals, is proposed. The combination of two bio-based organic acids, namely, citric acid (H₃Cit) and ascorbic acid (AsAc), enables complete recovery of Li and Co in just 1 h through mechanochemical leaching using ball milling. By using a relative molar ratio of H₃Cit:AsAc:LCO (1:0.5:1), this innovative approach offers an optimized leaching process. This method holds promise for significantly reducing the carbon footprint of future lithium-ion battery recycling efforts.