Synergetic pyrolysis of lithium-ion battery cathodes with polyethylene terephthalate for efficient metal recovery and battery regeneration

Zhe Meng; Jinchuan Dai; Xiao-Ying Lu; Kehua Wu; Yonghong Deng; Jun Wang; Kaimin Shih; Yuanyuan Tang

doi:10.1038/s44172-024-00317-x

Synergetic pyrolysis of lithium-ion battery cathodes with polyethylene terephthalate for efficient metal recovery and battery regeneration

Commun Eng. 2024 Nov 23;3(1):175. doi: 10.1038/s44172-024-00317-x.

Authors

Zhe Meng^#^{1

2}, Jinchuan Dai^#¹, Xiao-Ying Lu³, Kehua Wu³, Yonghong Deng⁴, Jun Wang⁴, Kaimin Shih², Yuanyuan Tang⁵

Affiliations

¹ Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
² Department of Civil Engineering, The University of Hong Kong, Hong Kong SAR, China.
³ Faculty of Science and Technology, Technological and Higher Education Institute of Hong Kong, Hong Kong SAR, China.
⁴ Department of Materials Science and Engineering, Southern University of Science and Technology, Shenzhen, China.
⁵ Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control, School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, China. tangyy@sustech.edu.cn.

^# Contributed equally.

PMID: 39580574
DOI: 10.1038/s44172-024-00317-x

Abstract

Spent LiNi_xCo_yMn_zO₂ (x + y + z = 1) and polyethylene terephthalate are major solid wastes due to the growing Li-ion battery market and widespread plastic usage. Here we propose a synergistic pyrolysis strategy to recover valuable metals by thermally treating LiNi_1/3Co_1/3Mn_1/3O₂ and polyethylene terephthalate. With polyethylene terephthalate assistance, LiNi_1/3Co_1/3Mn_1/3O₂ decomposes at 400 °C, and fully converts to Li₂CO₃, MnO, and Ni-Co alloy at 550 °C within 30 min, using a 1.0:0.3 mass ratio of LiNi_1/3Co_1/3Mn_1/3O₂ to polyethylene terephthalate. Furthermore, density functional theory calculations confirm the preference for O-Li bonding. Surface adsorption and free radical/gaseous reduction reactions explain the role of polyethylene terephthalate in promoting lattice destruction. The complete decomposition facilitates efficient post-treatment, achieving over 99% recovery of Li, Ni, Co, and Mn via water washing. Regenerated LiNi_1/3Co_1/3Mn_1/3O₂ was synthesized by using recovered Li- and transition metal-containing products as feedstocks. This study provided a chemical-free, energy-saving, and scalable recovery strategy while addressing polyethylene terephthalate waste minimization.

Abstract

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