Abstract
Solvent extraction of lithium (Li) from acidic leachates of spent batteries black mass (BM) over nickel (Ni), manganese (Mn), and cobalt (Co) can allow easy integration of Li recycling into conventional hydrometallurgical flowsheets, eliminating the need for thermal pretreatment of BM. In this study, a ternary organic phase consisting of iron (Fe3+), tributyl phosphate (TBP), and 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (P507) to selectively extract Li+ over Ni2+, Mn2+, and Co2+ has been developed. The extraction, scrubbing, stripping, and regeneration conditions were optimized, and McCabe–Thiele diagrams were constructed. An increasing P507/Fe (optimum 1.5–1.7) mole ratio was found to enhance Li release during water stripping but suppressed extraction. FTIR spectroscopy confirmed the stability of Fe3+ in the organic phase during water stripping. The Fe3+ preloaded solvent gave > 90% Li (7.7 g/L initially) extraction at an organic/aqueous phase ratio of 7 in four stages. After six cycles, the Li extraction efficiency was maintained, showing excellent selectivity, reducing NMC metal ions from 7.6–64 g/L to only 0–0.05 g/L in purified strip solution. The developed solvent system facilitates water stripping, eliminating the need for acids and alkalis, and allows easy integration in established chloride-based battery recycling processes, enabling early Li recovery from the leachate.
Data availability
The datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.
References
Saleem, U., Joshi, B. & Bandyopadhyay, S. Hydrometallurgical routes to close the loop of electric vehicle (EV) lithium-ion batteries (LIBs) value chain: A review. J. Sustain. Metall. 9(3), 950–971 (2023).
Ma, X. et al. The evolution of lithium-ion battery recycling. Nat. Rev. Clean Technol. 1(1), 75–94 (2025).
Saleem, U., Joshi, B. & Bandyopadhyay, S. Hydrometallurgical routes to close the loop of electric vehicle (EV) lithium-ion batteries (LIBs) value chain: A review. J. Sustain. Metall. https://doi.org/10.1007/s40831-023-00718 (2023).
Rinne, M., Lappalainen, H. & Lundström, M. Evaluating the possibilities and limitations of the pyrometallurgical recycling of waste Li-ion batteries using simulation and life cycle assessment. Green Chem. 27(9), 2522–2537 (2025).
Makuza, B. et al. Dry grinding-carbonated ultrasound-assisted water leaching of carbothermally reduced lithium-ion battery black mass towards enhanced selective extraction of lithium and recovery of high-value metals. Resour. Conserv. Recycl. 174, 105784 (2021).
Chen, H. et al. Selective leaching of Li from spent LiNi0.8Co0.1Mn0.1O2 cathode material by sulfation roast with NaHSO4‧H2O and water leach. Hydrometallurgy 210, 105865 (2022).
Xiao, J. et al. Novel targetedly extracting lithium: An environmental-friendly controlled chlorinating technology and mechanism of spent lithium ion batteries recovery. J. Hazard. Mater. 404, 123947 (2021).
Saleem, U. et al. Influence of pre-treatment of black mass from spent electric vehicle batteries on lithium recovery. Chem. Eng. J. Adv. 22, 100757 (2025).
Saleem, U. et al. Direct lithium extraction (DLE) methods and their potential in Li-ion battery recycling. Sep. Purif. Technol. 361, 131315 (2025).
Wesselborg, T., Virolainen, S. & Sainio, T. Recovery of lithium from leach solutions of battery waste using direct solvent extraction with TBP and FeCl3. Hydrometallurgy 202, 105593 (2021).
Shi, D. et al. Lithium extraction from low-grade salt lake brine with ultrahigh Mg/Li ratio using TBP–kerosene–FeCl3 system. Sep. Purif. Technol. 211, 303–309 (2019).
Zhou, Z. et al. Recovery of lithium from salt-lake brines using solvent extraction with TBP as extractant and FeCl3 as co-extraction agent. Hydrometallurgy 191, 105244 (2020).
Li, H. et al. An environmentally friendly lithium extraction system utilizing Cyanex 272 as iron-fixed reagent. Desalination 602, 118574 (2025).
Xiang, W. et al. Lithium recovery from salt lake brine by counter-current extraction using tributyl phosphate/FeCl3 in methyl isobutyl ketone. Hydrometallurgy 171, 27–32 (2017).
Duan, W. et al. Selective extraction of lithium from high magnesium/lithium ratio brines with a TBP–FeCl3–P204–kerosene extraction system. Sep. Purif. Technol. 328, 125066 (2024).
Su, H. et al. Recovery of lithium from salt lake brine using a mixed ternary solvent extraction system consisting of TBP, FeCl3 and P507. Hydrometallurgy 197, 105487 (2020).
Su, H. et al. Combining selective extraction and easy stripping of lithium using a ternary synergistic solvent extraction system through regulation of Fe3+ coordination. ACS Sustain. Chem. Eng. 8(4), 1971–1979 (2020).
Su, H. et al. Extraction relationship of Li+ and H+ using tributyl phosphate in the presence of Fe(III). Sep. Sci. Technol. 55(9), 1677–1685 (2020).
Balázs Illés, I. & Kékesi, T. Extraction of pure Co, Ni, Mn, and Fe compounds from spent Li-ion batteries by reductive leaching and combined oxidative precipitation in chloride media. Miner. Eng. 201, 108169 (2023).
Partinen, J. et al. The impact of chlorides on NMC leaching in hydrometallurgical battery recycling. Miner. Eng. 202, 108244 (2023).
Peris Sastre, J. P. et al. Resynthesis of cathode active material from heterogenous leachate composition produced by electric vehicle (EV) battery recycling stream. J. Clean. Prod. 429, 139343 (2023).
Zhang, L. et al. Lithium recovery from effluent of spent lithium battery recycling process using solvent extraction. J. Hazard. Mater. 398, 122840 (2020).
Guo, Y., Huang, J. & Feng, J. K. Solvent extraction separation and recovery of valuable metals from ternary cathode materials of spent lithium ion batteries. J. Environ. Manage 394, 127585 (2025).
Li, H. et al. Developing a green lithium extraction process: Insights into the TBP-P507 system and its industrial potential. J. Solid State Chem. 350, 125499 (2025).
Binnemans, K. & Jones, P. T. The twelve principles of circular hydrometallurgy. J. Sustain. Metall. 9(1), 1–25 (2023).
Farahbakhsh, J. et al. Direct lithium extraction: A new paradigm for lithium production and resource utilization. Desalination 575, 117249 (2024).
Wang, L. et al. A sustainable approach for advanced removal of iron from CFA sulfuric acid leach liquor by solvent extraction with P507. Sep. Purif. Technol. 251, 117371 (2020).
Kia, A. K. et al. Solvent extraction of lithium from brines with high magnesium/lithium ratios: Investigation on parameter interactions. Environ. Sci. Pollut. Res. 31(39), 52523–52539 (2024).
Saleem, U. et al. Recovery of lithium from oxalic acid leachate produced from black mass of spent electric vehicle Li-ion batteries. Chem. Eng. J. Adv. 20, 100648 (2024).
Nguyen, V. T. et al. Conversion of lithium chloride into lithium hydroxide by solvent extraction. J. Sustain. Metall. 9(1), 107–122 (2023).
Hyder, A. G. et al. Lithium recovery and conversion from wastewater produced by recycling of Li-ion batteries via two-stage electrodialysis. ACS Sustain. Chem. Eng. 13(12), 4651–4660 (2025).
Sun, Y. et al. Preparation of Li2CO3 by gas-liquid reactive crystallization of LiOH and CO2. Cryst. Res. Technol. 47(4), 437–442 (2012).
Acknowledgements
The authors would like to acknowledge Dr. Dag Øistein Eriksen from University of Oslo for supplying 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (P507).
Funding
Open access funding provided by NTNU Norwegian University of Science and Technology (incl St. Olavs Hospital - Trondheim University Hospital). The authors thank the EU’s Horizon Europe programme Revitalise (Grant agreement ID: 101137585) for funding. The work carried out is a part of the HolE-LIB project funded by NTNU Sustainability.
Author information
Authors and Affiliations
Contributions
Usman Saleem: Writing—original draft, Methodology, Investigation. Vanja Buvik: Writing—original draft, Supervision, Conceptualization. Hanna K. Knuutila: Writing—original draft, Supervision, Funding acquisition, Conceptualization. Sulalit Bandyopadhyay: Writing—original draft, Supervision, Funding acquisition, Conceptualization.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Additional information
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
About this article
Cite this article
Saleem, U., Buvik, V., Bandyopadhyay, S. et al. Selective extraction of lithium from acidic chloride leachates of spent batteries. Sci Rep (2026). https://doi.org/10.1038/s41598-026-43332-y
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41598-026-43332-y
