Decomposition of Deep Eutectic Solvent Aids Metals Extraction in Lithium-Ion Batteries Recycling

The application of deep eutectic solvents (DESs) to dissolve metal oxides in lithium-ion batteries (LIBs) recycling represents a green technological alternative to the mineral acids employed in hydrometallurgical recycling processes. However, DESs are much more expensive than mineral acids and must be reused to ensure economic feasibility of LIB recycling. To evaluate DES reusability, the role of the choline chloride-ethylene glycol DES decomposition products on metal oxides dissolution was investigated. The temperatures generally applied to carry on this DES leaching induced the formation of decomposition products that ultimately improved the ability to dissolve LIB metal oxides. The characterization of DES decomposition products revealed that the improved metal dissolution was mainly determined by the formation of Cl-3(-), which was proposed to play a pivotal role in the oxidative dissolution of LIB metal oxides.

Automated summary

The application of deep eutectic solvents (DESs) in lithium-ion battery (LIB) recycling as a green technological alternative to mineral acids has been investigated. The reusability of DESs was evaluated through the study on the decomposition products of choline chloride-ethylene glycol DES and their effect on metal oxides dissolution. The formation of Cl-3(-) was found to play a crucial role in the improved ability of DES to dissolve LIB metal oxides.