Selective recovery of Ni, Co, and Li from spent NCA lithium-ion batteries: 3D macroporous bio-based adsorbent and innovative leaching-adsorption strategy

Journal article, 2025

The increasing reliance on lithium-ion batteries (LIBs) has raised significant concerns regarding the disposal of spent batteries, particularly regarding the recovery of critical metals such as nickel (Ni), cobalt (Co), and lithium (Li). This study presents a novel hydrometallurgical strategy integrating selective leaching and bio-based adsorption for the efficient recovery of Ni, Co, and Li from LiNiCoAlO2 (NCA) cathode material, which contains aluminum (Al) impurities that are challenging to separate. A reagent-optimized leaching process using a stoichiometric H2SO4-H2O2 system enabled the efficient extraction of 98.4 % Li, 99.5 % Co, 99.1 % Ni, and 91.5 % Al under mild conditions. Subsequently, a novel 3D macroporous xanthate-functionalized wood flour (WT) adsorbent derived from waste biomass. At pH 5.5, WT enabled highly selective adsorption of Ni and Co (both >99 %), while Al was removed via pH-controlled precipitation and Li remained in solution, allowing for complete downstream recovery. Furthermore, the adsorbed Co and Ni ions were easily desorbed using a weak acid, facilitating adsorbent regeneration. Lithium in the leachate was subsequently recovered as high-purity Li2CO3 (99.2 %) through Na2CO3 precipitation. Mechanistic insights were obtained through FTIR, SEM, XPS, and XRD. This environmentally friendly, bio-based approach offers a cost-effective and scalable strategy for critical metal recovery, minimizing reagent consumption and secondary waste generation, thereby contributing to sustainable battery recycling and resource conservation.