Enhancements of dissociation of electrode materials in spent lithium-ion batteries by low-temperature heating pretreatment

• Published in: Process safety and environmental protection 2023-02, Vol.170, p.908-920
• Main Authors: Jiang, Si-qi, Nie, Chun-chen, Shi, Shun-xiang, Zhao, Yong-qiang, Li, Xiang-guang, Deng, Chao-zhu, Yang, Lu, Zhang, Ling, Zhu, Xiang-nan
• Format: Article
• Language: English
• Subjects: Efficient dissociation; Low-energy drive; Low-temperature heating; PVDF removal; Spent lithium-ion batteries
• ISSN: 0957-5820; 1744-3598
• DOI: 10.1016/j.psep.2022.12.061

The recycling of spent lithium-ion batteries (LIBs) is considered one of the prominent areas of interest in the global community owing to its economic interests and environmental protection. The existence of binder in batteries makes it difficult in the dissociation of electrode material from the fluid collector. This has prompted the need to develop an innovative means of dissociation. In this study, low-temperature heating with low-energy consumption is proposed to enhance the efficiency of dissociation. To determine the ideal heating temperature, the pyrolysis properties of electrode materials and binders were examined by the TG. The dissociation characteristics were analyzed by the grade of the collector (copper, aluminum) and the size composition of crushed electrode material. The surface morphology and element distribution of electrode material and the fluid collection were examined using SEM-EDS. The heating results shows that 500 ºC is the efficient low-temperature which is only slightly higher than the decomposition temperature of the PVDF. The SEM examination reveals that the electrode material's looser structure following heating makes it simpler for the electrode material to fall off of fluid-collecting surfaces, which intensifies dissociation. After heating, the crushing products of the anode and the cathode with size of − 0.074 mm increased by 5.94 % and 38.88 % respectively, the grade of the copper anode and the aluminum cathode in + 2 mm increased by 5.55 % and 38.92 % respectively.