Abstract:

Spent NCM523 was regenerated by a green method which is simple, feasible, and innovative. A low-eutectic mixture (LiNO₃-LiOH) was used as the lithium salt for regeneration in an air atmosphere. The regenerated product was characterized by X-ray diffraction, inductively coupled plasma spectroscopy, and scanning electron microscopy. The composition and crystal structure confirmed that the spent cathode was restored to its original state. Moreover, electrochemical results show that under the condition 300 ℃/3 h～850 ℃/4 h, the specific capacity of the regenerated material reached 161.2 mA·h/g(0.1 C, 2.8～4. 25 V) in the first discharge, and the coulomb efficiency was 87.8%. After 100 cycles at 1 C, the specific discharge capacity was 133.6 mA·h/g, confirming the high electrochemical performance of the rejuvenated material. The rate and recycling performance were much improved from those of untreated cathode materials and were similar to those of commercial anode materials. This research can promote the industrialization of cathode material recovery and provides a unique idea for the green recovery of other cathode materials such as LiMn₂O₄ and LiFePO₄. This method has good application prospects in lithium battery recovery.

Key words: spent lithium ion battery, anode material, eutectic, regenerate, lithium nickel cobalt manganese oxide