A facile and efficient recovery method of valuable metals from spent lithium-ion batteries via simultaneous leaching and separation strategy

Abstract

Traditional hydrometallurgical recycling methods present challenges including complex processes, significant metal loss, and high costs. To address these issues, this work introduces a facile and efficient recycling method for spent ternary cathode materials, which combines acid leaching and oxidation as well as ammonia leaching. Firstly, careful control of the phosphoric acid concentration and sodium persulfate dosage allows for the selective leaching of Li and Ni in the process of acid leaching and oxidation, and thus their leaching efficiencies can reach as high as 99.3 % and 97.2 % respectively. Meanwhile, Co and Mn can be separated in the form of Co₃O₄ and MnO₂ remaining in the waste residues. Secondly, based on the stability difference of complexes formed by cobalt and manganese with ammonia, Co can be selectively leached from waste residue through ammonia leaching, with the leaching efficiency reaching 93.2 %, while Mn is separated via reacting with CO₃²⁻ in the solution to form MnCO₃. Moreover, the mechanisms of selectively leaching Li and Ni during acid leaching and oxidation processes are revealed using characterization techniques such as XRD, ICP, SEM-EDS, and thermodynamic analysis. Finally, economic analysis shows that the benefits of this approach in terms of battery reuse are considerable, and there are clear advantages in terms of process simplification and operational safety. Compared to traditional hydrometallurgical recovery methods, which typically involve sequential separation after metal leaching, the proposed method achieves simultaneous leaching and separation of metals, thereby simplifying the recovery process and reducing metal losses.