Resource Recovery of Spent Lithium-Ion Battery Cathode Materials by a Supercritical Carbon Dioxide System

Yuanpeng Fu; Xianshu Dong; Burçak Ebin

doi:10.3390/molecules29071638

Resource Recovery of Spent Lithium-Ion Battery Cathode Materials by a Supercritical Carbon Dioxide System

Molecules. 2024 Apr 5;29(7):1638. doi: 10.3390/molecules29071638.

Authors

Yuanpeng Fu^{1

2

3}, Xianshu Dong¹, Burçak Ebin³

Affiliations

¹ School of Mining Engineering, Taiyuan University of Technology, Taiyuan 030024, China.
² Key Laboratory of Coal Processing and Efficient Utilization, China University of Mining and Technology, Ministry of Education, Xuzhou 221116, China.
³ Department of Chemistry and Chemical Engineering, Nuclear Chemistry and Industrial Material Recycling, Chalmers University of Technology, 412 96 Gothenburg, Sweden.

Abstract

The increasing global market size of high-energy storage devices due to the boom in electric vehicles and portable electronics has caused the battery industry to produce a lot of waste lithium-ion batteries. The liberation and de-agglomeration of cathode material are the necessary procedures to improve the recycling derived from spent lithium-ion batteries, as well as enabling the direct recycling pathway. In this study, the supercritical (SC) CO₂ was innovatively adapted to enable the recycling of spent lithium-ion batteries (LIBs) based on facilitating the interaction with a binder and dimethyl sulfoxide (DMSO) co-solvent. The results show that the optimum experimental conditions to liberate the cathode particles are processing at a temperature of 70 °C and 80 bar pressure for a duration of 20 min. During the treatment, polyvinylidene fluoride (PVDF) was dissolved in the SC fluid system and collected in the dimethyl sulfoxide (DMSO), as detected by the Fourier Transform Infrared Spectrometer (FTIR). The liberation yield of the cathode from the current collector reaches 96.7% under optimal conditions and thus, the cathode particles are dispersed into smaller fragments. Afterwards, PVDF can be precipitated and reused. In addition, there is no hydrogen fluoride (HF) gas emission due to binder decomposition in the suggested process. The proposed SC-CO₂ and co-solvent system effectively separate the PVDF from Li-ion battery electrodes. Thus, this approach is promising as an alternative pre-treatment method due to its efficiency, relatively low energy consumption, and environmental benign features.

Keywords: cathode material; dimethyl sulfoxide; liberation; lithium-ion batteries; supercritical CO2.

Grants and funding

This work was supported by the Swedish Energy Agency Battery Fund Program (Project No: P2019-90078), and the Fundamental Research Program of Shanxi Province (202103021223045), Shanxi Scholarship Council of China (2022-062) and Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi (2021L064).