Separation of nickel from cobalt and manganese in lithium ion batteries using deep eutectic solvents

• Published in: Green chemistry : an international journal and green chemistry resource : GC Vol. 24; no. 12; pp. 4877 - 4886
• Main Authors: Thompson, Dana L, Pateli, Ioanna M, Lei, Chunhong, Jarvis, Abbey, Abbott, Andrew P, Hartley, Jennifer M
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 20.06.2022
• Subjects: Batteries; Chemical precipitation; Cobalt; Electric vehicles; Electrode materials; Green chemistry; Lithium; Lithium-ion batteries; Manganese; Manganese oxides; Nickel; Oxalates; Oxalic acid; Rechargeable batteries; Solvents
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/d2gc00606e

A cornerstone of the decarbonisation agenda is the use of lithium ion batteries, particularly for electric vehicles. It is essential that effective recycling protocols are developed and this includes the ability to selectively digest and recover components of the cathode materials, most commonly including manganese, cobalt and nickel. This study shows a method by which nickel oxide can be efficiently separated from cobalt and manganese oxides using an oxalic acid-based deep eutectic solvent. The subsequent addition of water to the pregnant solution enables the co-precipitation of cobalt and manganese oxalates. This permits a route to the reformulation of the active materials from high cobalt and manganese content to high nickel content. Cobalt and manganese were selectively leached from LiNMC using an oxalic acid : choline chloride deep eutectic solvent, resulting in a nickel-enriched solid residue.