Recovery of Cobalt and Nickel from Hard Alloy Scraps for the Synthesis of Li(Ni 1−x−y Co x Mn y )O 2 Lithium-Ion Battery Cathodes

The increasing demand for lithium-ion batteries (LIBs) has resulted in raising the price of cobalt (Co) and nickel (Ni), which are key components of the cathode materials of LIBs and their deposits in the earth’s crust are limited. This paper aims to recover Co and Ni from hard alloy scraps (HASs) containing a high concentration of Co and Ni for preparing Li(Ni1−x−yCoxMny)O2 [e.g., Li(Ni1/3Co1/3Mn1/3)O2 (NCM-111) and Li(Ni0.6Co0.2Mn0.2)O2 (NCM-622)] cathodes. Without separating Ni and Co through a solvent extraction process, the Co and Ni can be co-precipitated to directly synthesize (Ni1−x−yCoxMny)(OH)2 precursors. In this way, the production costs of NCM-111 and NCM-622 can be reduced by 4538 and 8126 dollars per ton, respectively. The obtained NCM-111 and NCM-622 exhibit initial discharge capacities of 158.1 mAh g−1 and 158.5 mAh g−1, respectively, and their capacity retention rates are 86.8% (NCM-111) and 85.6% (NCM-622) after 100 cycles. Thus, the combined acid leaching and co-precipitation can be used for valorizing HASs as well as other types of waste Ni- and Co-containing waste alloys for the synthesis of NCMs for LIBs. Schematic illustration of the preparation of NCM materials from HASs.