(711c) Development of a Closed-Loop Process for Separation and Recovery of Li and Co from LiCoO2

Lithium-ion batteries (LiBs) power most of the modern world. The use of LiBs has expanded from portable electronics to electric vehicles, homes, and even to the electrical grid. However, the recycling of LiBs presents new challenges to the battery industry. In this work, we introduce a novel closed-loop process to extract Li and Co metals from lithium cobalt oxide (LiCoO₂) using oxalic acid. During the digestion process, Co precipitates as cobalt oxalate dihydrate (CoC₂O₄·2H₂O), and Li remains in the solution as lithium oxalate (Li₂C₂O₄) which provides an efficient separation. The cobalt oxalate is converted back to cobalt oxide by calcination, whereas the Li can be precipitated in the form of carbonate or phosphate from the aqueous oxalate phase. The remaining oxalate in the filtrate after Li precipitation can be recycled using an acid cation-exchange resin process. The used resins can also be recycled, providing a sustainable process for regenerating the oxalic acid. The ability to recover oxalate provides both an economic and environmental advantage compared with other mineral acid (H₂SO₄, HCl, etc.) processes. This presentation will describe the experimental and mechanistic details of the extraction and separation of Li and Co metals and the recovery of oxalic acid. In addition, a techno-economic analysis will be presented comparing our closed-loop oxalic acid process with other conventional hydrometallurgical processes.