Recovery of Al, Co, Cu, Fe, Mn, and Ni from spent LIBs after Li selective separation by COOL‐Process – Part 2: Solvent Extraction from Sulphate Leaching Solution

Abstract

The market for lithium‐ion batteries (LIB) is experiencing substantial growth, what is owed to electromobility and the growing demand for cordless devices. Securing the raw material base for LIB is mandatory to achieve the objectives of EU commission's Green Deal. This implies not only sufficient access to lithium but also the accompanying metals, above all Co, Ni, Mn. After preceding recovery of Li2CO3 by the COOL‐Process and subsequent acid digestion of the Li‐free black mass, value metals, such as Co, Cu, Ni, and Mn were recovered by counter‐current solvent extraction. Fe (98.5 ± 0.65 %), Co/Mn (99.8 ± 0.78 %; 99.9 ± 1.11 %), Al (99.7 ± 1.07 %) and Cu/Ni (97.8 ± 1.46 %; 98.6 ± 1.32 %) were selectively extracted with high discriminatory power using cationic exchangers and solvating extractants such as D2EHPA and TBP, respectively. This way, a complete, holistic recycling process for LIB is at hand that allows for recovering housing material, lithium and the accompanying metals almost quantitatively.

Reaction–Diffusion Coupling Facilitates the Sequential Precipitation of Metal Ions from Battery Feedstock Solutions

“…We note that the recovery rate of our method is lower than some reported methods, − partially due to the lower NaOH concentration compared to the metal-salt-containing feedstock. However, the selective precipitation of Mn was achieved without requiring organic solvents, heating, or specialty chemicals. , …”

“…However, the selective precipitation of Mn was achieved without requiring organic solvents, heating, or specialty chemicals. 15,53 Systematic Optimization of Control Parameters. To optimize the separation efficiency, we investigated the role of multiple parameters, namely, the concentration of the precipitating agent, the gel-to-feedstock volume ratio, and the size of the reactor.…”

“…In this context, recycling spent batteries and electronics has emerged as a viable option for recovering critical materials. − Currently, separating these components from feedstocks relies on adsorbents that bind to specific metal ions, membranes that selectively interact with the target species, and/or toxic solvents that require special treatment for safe disposal. − These methods have demonstrated success in some applications but are beset by technical challenges, including the ineffective separation of ions of similar chemistries, the scaling and fouling of membranes, the degradation of adsorbents, the contributions to high carbon dioxide emissions, and the high energy input required for sustaining the driving forces of separation. One widely used and relatively mild approach is selective precipitation; − a feedstock solution is mixed with a precipitating agent, and the insoluble products are recovered.…”

The COOL Process: A Holistic Approach Towards Lithium Recycling

“…15 Flowsheet of the COOL process with respect to primary resources. The solid silicate residues from the leaching step can be used to produce geopolymers separation of the Mn/Co and Ni/Cu mixtures still have to be carried out [45] (Figure 15). Thereby it could be shown successfully that the COOL process allows a holistic valorization of the black mass by using a minimum of chemicals as well as energy (Figure 16).…”

The COOL process – a holistic approach towards Lithium recycling

“…By increasing the pH of the aqueous phase to 6.0, Al is separated by precipitation of Al(OH) 3 , leaving a Ni/Cu mixture after ltration. Further investigations on the separation of the Mn/Co and Ni/Cu mixtures still have to be carried out [41].…”