Semi-continuous pilot-scale validation of an integrated pyro–hydrometallurgical process for lithium-ion battery black mass recycling

An integrated pyro–hydrometallurgical recycling process was validated at semi-continuous pilot scale for the treatment of nickel–manganese–cobalt (NMC) lithium-ion battery black mass derived from end-of-life electric vehicle batteries. A total of 40 kg of real black mass was processed through a flowsheet combining electrolyte hydrolysis, carbothermic reduction, aqueous leaching, and selective separation stages for lithium, cobalt, and nickel recovery. Lithium was recovered as lithium carbonate through combined electrolyte treatment and carbothermic processing, while cobalt was selectively extracted using a tailored deep eutectic solvent route and nickel was recovered via dimethylglyoxime precipitation. Pilot-scale operation achieved 92.45% total lithium recovery (Li 2 CO 3 -equivalent) with 95.53% purity, 80.8% cobalt recovery as oxide with 94.7% purity, and 82.98% nickel recovery with a final purity of 98.35%. Compared with laboratory-scale benchmarks, lithium and cobalt recoveries improved at pilot scale, evidencing increased process robustness and operational stability, whereas nickel precipitation was identified as the main optimization target for further scale-up. The results provide experimentally validated data supporting the transition of integrated lithium-ion battery recycling routes from laboratory research towards industrial implementation.