Recycling of valuable metals from spent cathode material by organic pyrolysis combined with in-situ thermal reduction

Guangwen Zhang; Zimeng Liu; Xue Yuan; Yaqun He; Neng Wei; Haifeng Wang; Bo Zhang

doi:10.1016/j.jhazmat.2022.128374

Recycling of valuable metals from spent cathode material by organic pyrolysis combined with in-situ thermal reduction

J Hazard Mater. 2022 May 15:430:128374. doi: 10.1016/j.jhazmat.2022.128374. Epub 2022 Jan 29.

Authors

Guangwen Zhang¹, Zimeng Liu², Xue Yuan³, Yaqun He⁴, Neng Wei³, Haifeng Wang³, Bo Zhang⁵

Affiliations

¹ School of Environment Science and Spatial Informatics, China University of Mining and Technology, No.1 Daxue Road, Xuzhou, Jiangsu 221116, China; Key Laboratory of Solid Waste Treatment and Resource Recycle, Ministry of Education, Southwest University of Science and Technology, No.59 Qinglong Road, Mianyang, Sichuan 621010, China. Electronic address: gwzhang@cumt.edu.cn.
² School of Environment Science and Spatial Informatics, China University of Mining and Technology, No.1 Daxue Road, Xuzhou, Jiangsu 221116, China.
³ School of Chemical Engineering and Technology, China University of Mining and Technology, No.1 Daxue Road, Xuzhou, Jiangsu 221116, China.
⁴ School of Chemical Engineering and Technology, China University of Mining and Technology, No.1 Daxue Road, Xuzhou, Jiangsu 221116, China. Electronic address: yqhe@cumt.edu.cn.
⁵ Key Laboratory of Coal Processing and Efficient Utilization of Ministry of Education, China University of Mining and Technology, No. 1 Daxue Road, Xuzhou, Jiangsu 221116, China.

PMID: 35150992
DOI: 10.1016/j.jhazmat.2022.128374

Abstract

From the perspective of environmental protection and resource recovery, recycling of spent lithium-ion batteries is a meaningful process. In this study, the removal of organics, liberatioin of electrode material, and reduction of high valence transition metal, as the key points in recycling efficiency of valuable metals, have been firstly achieved simultaneously by low temperature heat treatment recycling process. Pyrolysis characteristics of organics, phase transition behavior of spent cathode material and the thermal reduction mechanism were evaluated in the meantime. Results demonstrate that organics can be removed and the liberation of electrode materials can be improved by pyrolysis. High-valence transition metals in cathode materials are synchronously reduced to CoO, NiO, MnO, Ni, and Co based on the reducing action of organics, aluminum foil and conductive additives. At the same time, Li element exists in the form of Li₂CO₃, LiF and aluminum-lithium compound that can be recycled by water-leaching in the water impact crushing process while transition metals can be recycled by acid leaching without reducing agents. 81.26% of Li can be recycled from water-leaching process while the comprehensive recovery rate of Ni, Co, Mn is 92.04%, 93.01%, 92.21%, respectively. This study may provide an environmentally-friendly recycling flowchart of spent lithium-ion batteries.

Keywords: Heating treatment; Organic removal; Spent lithium-ion batteries; Thermal reduction; Valuable metal recycling.