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Deep eutectic solvents for cathode recycling of Li-ion batteries


As the consumption of lithium-ion batteries (LIBs) for the transportation and consumer electronic sectors continues to grow, so does the pile of battery waste, with no successful recycling model, as exists for the lead–acid battery. Here, we exhibit a method to recycle LIBs using deep eutectic solvents to extract valuable metals from various chemistries, including lithium cobalt (iii) oxide and lithium nickel manganese cobalt oxide. For the metal extraction from lithium cobalt (iii) oxide, leaching efficiencies of ≥90% were obtained for both cobalt and lithium. It was also found that other battery components, such as aluminium foil and polyvinylidene fluoride binder, can be recovered separately. Deep eutectic solvents could provide a green alternative to conventional methods of LIB recycling and reclaiming strategically important metals, which remain crucial to meet the demand of the exponentially increasing LIB production.

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Fig. 1: Battery recycling schematic.
Fig. 2: Extraction of cobalt using ChCl:EG DES.
Fig. 3: Characterization of precipitate from leaching cobalt ions from the DES.
Fig. 4: Recyclability of the DES.
Fig. 5: Leaching efficiency of NMC powder dissolved in the DES at 180 °C.

Data availability

The data that support the plots and tables within this paper and its Supplementary Information files, as well as the other findings of this study, are available from the corresponding author upon reasonable request.


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The authors thank A. Kabbani and A. Puthirath for useful discussion, and L. Alexander for assistance with the NMC dissolution experiments. M.K.T. acknowledges the National Science Foundation for continued support and funding. This study is based on work supported by the National Science Foundation Graduate Research Fellowship Program under grant number 1450681. Any opinions, findings, conclusions or recommendations expressed are those of the authors and do not necessarily reflect the views of the National Science Foundation.

Author information




M.-T.F.R. conceived of the experimental design. M.K.T. performed the experiments and, alongside M.-T.F.R., co-wrote the paper and analysed the data. K.K. assisted in figure creation, as well as XPS and electrochemical experimentation and analysis. P.M.A. and G.B. conceived of and contributed to the overall project planning.

Corresponding authors

Correspondence to Ganguli Babu or Pulickel M. Ajayan.

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Supplementary Information

Supplementary Discussion, Supplementary Tables 1–3, Supplementary Figures 1–6, Supplementary References

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Tran, M.K., Rodrigues, MT.F., Kato, K. et al. Deep eutectic solvents for cathode recycling of Li-ion batteries. Nat Energy 4, 339–345 (2019).

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