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

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.