(524b) Two-Zone Displacement Chromatography Method for the Recovery of High-Purity Li, Co, Ni, and Mn from Mixtures Derived from Lithium-Ion Battery Cathode Materials

The market share of electric vehicles (EVs) has increased rapidly in recent years, driven by the need to reduce carbon dioxide emissions associated with conventional vehicles powered by fossil fuels. The worldwide sales of EVs have increased from 0.54 million units in 2015 to 10.5 million units in 2022, and are projected to reach 56 million units in 2040. Lithium (Li), cobalt (Co), nickel (Ni), and manganese (Mn) are four essential elements used in the cathode materials of the lithium-ion batteries (LIBs) employed to power EVs. Currently, Li, Co, Mn, and Ni oxides are first obtained from mineral ores or brines, purified to battery-grade precursors, and then used to make LIBs. At the end of their life, up to 12 years, waste LIBs are mostly landfilled. If the present life cycle of LIBs remains unchanged, Co and Li will be mostly depleted by 2045.

In this study, we developed a two-zone displacement chromatography purification method to recover individual battery-grade Li, Co, Ni, and Mn from the cathode materials of waste LIBs. An efficient model-based approach was used to develop the displacement chromatography process. The constant-pattern design method based on the intrinsic parameters was developed to generate the operating parameters for columns with various diameters and lengths. A first zone was designed to separate the multi-component mixture into individual battery-grade components, with a yield of 80%. The collected binary mixed bands from the first zone were further separated in a second zone. The residual mixed bands from the second zone were recycled to its feed to increase the yields of high-purity (>99.5%) products to over 99%. Experiments using different feedstocks, presaturants, and displacers, were carried out for further testing of the versatile design method. The total productivity of the high-purity products reached 20 kg of pure (>99.5%) metal ions per m³ of sorbent per day, with overall yields of 99% for the two-zone displacement method.