Full-Component Pyrolysis Coupled with Reduction of Cathode Material for Recovery of Spent LiNixCoyMnzO₂ Lithium-Ion Batteries

Abstract

Wide application of NCM (LiNixCoyMnzO2) lithium-ion batteries (LIBs) for electric vehicles indicates their high scrap amount in the near future. Thus, spent NCM LIBs must be recycled from the economic and environment viewpoint. In this context, a novel process was developed to achieve efficient extraction of valuable metals and harmless treatment of organics in NCM LIBs through full-component pyrolysis. Organic substances, such as a separator and a binder, were recovered in the form of pyrolytic oil and gas, whereas the cathode material was simultaneously dissociated and reduced, realizing the subsequent extraction of valuable metals by acid leaching without a reducing agent. The leaching efficiencies of lithium, nickel, cobalt, and manganese were over 99.5% under optimum conditions: a pyrolysis temperature of 450 °C, a pyrolysis time of 60 min, and a nitrogen flow rate of 100 mL/min. In addition, the reduction mechanism of the cathode material was investigated by experimental design and analysis of pyrolytic gas.