Efficient reduction of spent cathode materials via in-situ thermal reduction by defect-rich petroleum coke

• Published in: Separation and purification technology Vol. 334; p. 126029
• Main Authors: Cao, Ning, Zhang, Yang, He, Zhengqiu, Dong, Zhiliang, Bi, Xinze, Kong, Shuoshuo, Wang, Luhai, He, Shengbao, Hu, Han, Wu, Mingbo
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 14.04.2024
• Subjects: Carbon defect; Cathode materials; Petroleum coke; Reduction roasting; Spent lithium-ion battery; Spent lithium-ion battery; Reduction roasting; Carbon defect; Cathode materials; Petroleum coke
• ISSN: 1383-5866; 1873-3794
• DOI: 10.1016/j.seppur.2023.126029

[Display omitted] •Defect-rich PC is firstly used as the adjuvant for thermal reduction of S-NCM.•Insoluble Ni, Co, MnO and soluble Li2CO3 are formed in situ by only 5.8% PC.•High value-added utilization of roasting by-products—CO2 is realized.•The reducibility mechanism of PC to S-NCM is explored by DFT calculations. Based on the dual attributes of environmental risk and resource value of spent Lithium-ion batteries (LIBs), low-cost and high-efficiency recovery methods of valuable metals from spent LIBs have been widely studied. Here, a strategy to efficiently recover valuable metals from spent cathode materials using defect-rich petroleum coke (PC) is proposed. The results show that only 5.8 % PC is required to reduce the spent cathode materials at 700 °C for 60 min, which shows strong reducibility. Meanwhile, thermodynamic and DFT calculations explore the mechanism of strong reducibility of defect-rich PC in the recovery of spent cathode materials. Based on the strong reduction effect of PC and the synergistic effect of gas–solid reaction and solid–solid reaction, the spent cathode materials are converted to soluble Li2CO3 as well as insoluble Ni, Co and MnO. The CO2 produced in the PC-assisted roasting process can participate in the Boudoureau reaction and the formation of Li2CO3 in situ, accelerating the efficient reduction of spent cathode materials and realizing the high value-added utilization of the roasting byproducts—CO2. The regenerated cathode materials show excellent electrochemical properties. This closed‐loop recovery process uses PC instead of expensive graphite, with a profit of around 6.67 $∙kg−1 cell, which reduces the cost.