Hydration Equilibrium-controlled Cation-Anion Coordination Competition for Precise Recovery of All Valuable Metals from Spent Lithium-ion Batteries

Abstract

The selective recovery of metals from spent lithium-ion batteries (LIBs), particularly from Ni-based ternary (NCM) cathode materials, is a significant challenge due to their complex elemental composition. Herein, we present a novel, sustainable method that addresses the limitations of traditional techniques, which often rely on extractants or precipitants for metal separation. By precisely controlling temperature and H2O content in deep eutectic solvents (DESs), we achieve efficient and selective recovery of Ni, Li, Co, and Mn, with recovery efficiencies >94% and product purities >97%, all without the need for additional chemicals. Additionally, the used DES can be regenerated by evaporating H2O and replenishing reagents, enhancing both sustainability and cost-effectiveness. A successful scale-up in a 10 L reaction unit validates the industrial feasibility of the process. This work presents a major advancement in the sustainable recycling of spent LIBs, offering a practical and eco-friendly solution for efficient multi-metal separation and resource recovery.