Influence Mechanism of Phase Change on Leaching of Metal Elements from Ternary Lithium-Ion Battery Waste in Citric Acid

Li, Ni and Co elements in ternary lithium-ion batteries are rare metal resources in China, and recycling these metal elements has a great environmental and economic significance. In this work, a clean selective leaching method for Li, Ni, Co and Mn elements from ternary lithium-ion battery waste was proposed. The mixed positive and negative electrode powders were activated by anaerobic roasting at different temperatures and times. Then, the roasted samples were leached in citric acid under the same conditions. Under suitable roasting conditions, the leaching efficiencies of Li, Ni, Co and Mn are 99.93%, 95.25%, 97.22% and 99.94%. The leaching efficiency of Cu is < 1%, which realizes the selective leaching of metal elements in the ternary lithium-ion battery waste. Moreover, the promoting mechanism of anaerobic roasting on leaching of metal elements in spent lithium-ion batteries was discussed from the view of material structure and phase composition.