Recycling of waste lithium-ion batteries via a one-step process using a novel deep eutectic solvent

Deep eutectic solvents (DESs) possess excellent solubility and selectivity, making them suitable for extracting valuable metals and serving as a green alternative in the recycling process. This work introduces a low-viscosity DES consisting of dimethylthetin, oxalic acid, and water for the comprehensive recovery of cathode materials from LIBs. Leaching parameters such as ratio (1:1), leaching temperature (60 °C), and reaction time (15 min) for were systematically optimized, resulting in a selective separation efficiency of 99.98 % for lithium ions. Furthermore, in-situ regeneration of the precursor can be achieved during the leaching process. Charge-discharge tests indicate that the initial charge and discharge capacities of the regenerated battery are 166.8 mAh/g and 138.4 mAh/g, respectively. The DES demonstrates stability and can be easily recycled by replenishing the consumed components. This proposed strategy facilitates the reintroduction of nonrenewable resources into the supply chain and reduces the environmental impact of heavy metals, aligning with the principles of a circular economy.