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Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries


High-energy density, improved safety, temperature resilience and sustainability are desirable properties for lithium-battery electrolytes, yet these metrics are rarely achieved simultaneously. Inspired by the compositions of clean fire-extinguishing agents, we demonstrate inherently safe liquefied gas electrolytes based on 1,1,1,2-tetrafluoroethane and pentafluoroethane that maintain >3 mS cm−1 ionic conductivity from −78 to +80 °C. As a result of beneficial solvation chemistry and a fluorine-rich environment, lithium cycling at >99% Coulombic efficiency for over 200 cycles at 3 mA cm−2 and 3 mAh cm−2 was demonstrated in addition to stable cycling of Li/NMC622 full batteries from −60 to +55 °C. In addition, we demonstrate a one-step solvent-recycling process based on the vapour pressure difference at different temperatures of the liquefied gas electrolytes, which promises sustainable operation at scale. This work provides a route to sustainable, temperature-resilient lithium-metal batteries with fire-extinguishing properties that maintain state-of-the-art electrochemical performance.

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Fig. 1: Design of LGEs.
Fig. 2: Properties of LGEs.
Fig. 3: Bulk structure and MD simulation results of the formulated electrolytes.
Fig. 4: Electrochemical performance of Li-metal anode and Li/NMC622 cells in different electrolytes.
Fig. 5: Visualization of Li morphology and SEI.
Fig. 6: SEI information obtained by XPS measurements with electrolytes.
Fig. 7: Recycling concept and demonstration of LGEs.

Data availability

All the data generated in this study are included in the Article and its Supplementary Information. Source data are provided with this paper.

Code availability

The MD simulation code is available in Supplementary Data 1.


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Y. Yin and Y.S.M. thank C. Rustomji from South 8 Technologies for the fruitful discussions. The experimental part of the work performed at UCSD was supported by Sustainable Power and Energy Center (SPEC) and Zable endowed chair fund for energy technologies. The molecular modelling performed at ARL was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Vehicle Technology Office of the U.S. DOE through Applied Battery Research for Transportation (ABRT) program via interagency agreement 89243319SEE000004 supporting contract No. DE-SC0012704. The cryo-FIB and SEM were developed and performed in part at the San Diego Nanotechnology Infrastructure (SDNI) of UCSD, a member of the National Nanotechnology Coordinated Infrastructure, which is supported by the National Science Foundation (Grant ECCS-1542148). Y. Yin thanks I. C. Tran for their help regarding XPS experiments performed at the University of California Irvine Materials Research Institute (IMRI) using instrumentation funded in part by the National Science Foundation Major Research Instrumentation Program (grant CHE-1338173). The authors acknowledge the use of Raman instrumentation supported by NSF through the UC San Diego Materials Research Science and Engineering Center (UCSD MRSEC), grant number DMR-2011924. We appreciate the supply of 20 μm lithium foils from Applied Materials.

Author information

Authors and Affiliations



Y. Yin, Y. Yang and Y.S.M. formulated the electrolytes and designed the experiments. Y.S.M., M.M. and Y. Yang conceived the recycling process. Y. Yin and Y. Yang designed and performed the demonstration experiments. Y.S.M. and Y. Yang supervised the project. Y. Yin and Y. Yang conducted the electrochemical experiments. Y. Yin, D.C. and A.L. performed the flame-extinguishing tests with some guidance from Z.C. Raman spectroscopy was performed by Y. Yin based on cells designed by D.M.D. The force field was developed by O.B., who also carried out the MD simulations. D.C. performed the cryo-FIB. W.L. and Y. Yin performed the XPS characterization and analysis. J.H. performed the DFT calculations. G.R. and A.L. helped with control experiments. B.L. performed the cryo-TEM. Y. Yin, Y. Yang, D.C., O.B. and M.M. prepared the manuscript with input from all co-authors. All authors have given approval to the final version of the manuscript.

Corresponding authors

Correspondence to Yangyuchen Yang, Oleg Borodin or Y. Shirley Meng.

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Competing interests

Y. Yin, Y. Yang, M.M. and Y.S.M. declare that this work has been filed as US Provisional Patent Application No. 63/268,910. The remaining authors declare no competing interests. Y.S.M. is a member of the scientific advisory board for South 8 Technologies.

Peer review

Peer review information

Nature Energy thanks Jinkui Feng, Jang-Kyo Kim and Matthew McDowell for their contribution to the peer review of this work.

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Supplementary information

Supplementary Information

Supplementary Figs. 1–32, Notes 1–6 and Tables 1–4.

Supplementary Video 1

Fire-douse test of air to check the fire-extinguishing effect.

Supplementary Video 2

Fire-douse test of CO2 to check the fire-extinguishing effect.

Supplementary Video 3

Fire-douse test of TFE to check the fire-extinguishing effect.

Supplementary Video 4

Fire-douse test of PFE to check the fire-extinguishing effect.

Supplementary Video 5

Fire-douse test of Me2O to check the fire-extinguishing effect.

Supplementary Video 6

Fire-douse test of 1 M LiFSI-Me2O-TFE-PFE to check the fire-extinguishing effect.

Supplementary Video 7

Gas-venting test of cycled Li/NMC622 after 100 cycles and then charged at 4.05 V to check the fire-extinguishing effect of cycled electrolytes inside the cell.

Supplementary Data 1

MD simulation code and the associated force-field files needed to perform MD simulations.

Supplementary Data 2

Source data for Supplementary Fig. 23a.

Source data

Source Data Fig. 4

Source data for main text figure 4

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Yin, Y., Yang, Y., Cheng, D. et al. Fire-extinguishing, recyclable liquefied gas electrolytes for temperature-resilient lithium-metal batteries. Nat Energy 7, 548–559 (2022).

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