Selective and sustainable recovery of lithium from black mass via microwave and green leaching techniques

The growing demand for lithium-ion batteries (LIBs) has intensified the need for efficient and sustainable recycling processes to recover critical metals such as lithium, cobalt, Ni, and Mn from spent batteries. This study presents a novel microwave-assisted pyrometallurgical-hydrometallurgical approach for the selective and high-yield recovery of Li and from industrial black mass (BM). The process integrates microwave-induced carbothermic reduction with a two-step leaching strategy, water leaching for Li₂CO₃ recovery and deep eutectic solvent (DES)-based leaching for Co, Ni, and Mn extraction. Advanced characterization techniques (SEM/EDS, ICP, XRD) confirmed the selective separation of metals. In the optimized version, the proposed process allowed up to 85% Li efficiency. A sustainability assessment using the ESCAPE index demonstrated the environmental advantages of this method over conventional acid-based hydrometallurgy. This scalable and eco-friendly process offers a suitable pathway for Li recovering from spent LIBs, aligning with circular economy principles and future industrial implementation.