How can one recycle lithium from spent Li-ion batteries (LIBs) when a pyrometallurgical route is chosen? In a new paper by HiTemp researchers of the KU Leuven Institute for Sustainable Metals and Minerals, a chlorination process was further developed to do just that. As a starting material, we used the slag that is obtained when processing End-of-Life LIBs in a pyrometallurgical (smelting reduction) process. In this work the effect of the chlorinating agent was investigated, as a follow-up of a previous paper on the same process.

With the rapid growth of the electric vehicle (EV) and energy storage system (ESS) markets, the demand for lithium-ion batteries (LIBs) has skyrocketed, highlighting the importance of securing a sustainable supply of lithium. This study explores chlorination roasting as a method for recovering lithium from Li-containing slag, which is a promising alternative lithium source obtained from pyrometallurgical LIB recycling process. We investigate the efficiency of chlorination roasting in producing technical grade (TG) lithium chloride (LiCl) from the slag and quantitatively analyze the impurity behavior during the process.

Different chlorinating agents, including CaCl₂, NaCl, and PVC, are evaluated for their effectiveness in lithium recovery and purity. The results indicate that CaCl₂ is the most effective in achieving high lithium recovery and LiCl purity, at approximately 90%. This offers a promising solution for sustainable lithium production. This research would highlight the importance of developing efficient recycling methods to meet the growing demand for lithium in EV and ESS applications.

Further refining of LiCl

Finally, even in the case a pure LiCl product is obtained from the chlorination roasting process, a further refining process is required to further purify the “technical-grade” LiCl quality (e.g. 90% purity) into battery-grade quality Li products.

This was demonstrated in previous work at KU Leuven, by the SOLVOMET Group in a patented process that allows to process solid technical-grade LiCl into battery-grade LiOH∙H₂O (cf. patent application WO2021228936A1: Method for producing battery grade lithium hydroxide monohydrate: Priority 2020-05-13, Filed 2021-05-12, Published 2021-11-18: https://patents.google.com/patent/WO2021228936A1/en).

References

Chlorination process:

• (Part I) Heo, J., Jones, P.T., Blanpain, B. et al. Chlorination Roasting of Li-Bearing Minerals and Slags: Combined Evaluation of Lithium Recovery Ratio and Lithium Chloride Product Purity. J. Sustain. Metall. (2023). https://doi.org/10.1007/s40831-023-00729-7
• (Part II) Heo, J., Jones, P.T., Guo M., Blanpain, B. Effect of Chlorinating Agents on Lithium Recovery and Product Purity from Lithium-ion Battery (LIB) Recycling Slags via Chlorination Roasting Process. MINERAL PROCESSING AND EXTRACTIVE METALLURGY REVIEW.  https://doi.org/10.1080/08827508.2024.2334943

LiCl to LiOH process:

• Avdibegović D, Nguyen VT, Binnemans K (2022) One-step solvometallurgical process for purification of lithium chloride to battery grade. J Sustain Metall 8:893–899. https://doi.org/10.1007/s40831-022-00540-w
• Nguyen, V.T., Deferm, C., Caytan, W. et al. Conversion of Lithium Chloride into Lithium Hydroxide by Solvent Extraction. J. Sustain. Metall. 9, 107–122 (2023). https://doi.org/10.1007/s40831-022-00629-2

Acknowledgements

The authors gratefully acknowledge the financial support for the KU Leuven C3 project “Solvometallurgy-based Process for Battery-grade Lithium Refining (SOLVOLi)” (3E200922) from Industrieel Onderzoeksfonds (IOF), KU Leuven. This work was partly supported by the Korea Institute of Energy Technology Evaluation and Planning (KETEP) and the Ministry of Trade, Industry & Energy (MOTIE) of the Republic of Korea (20227A10100030).