Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published December 7, 2018 | Supplemental Material
Journal Article Open

Room-temperature cycling of metal fluoride electrodes: Liquid electrolytes for high-energy fluoride ion cells


Fluoride ion batteries are potential "next-generation" electrochemical storage devices that offer high energy density. At present, such batteries are limited to operation at high temperatures because suitable fluoride ion–conducting electrolytes are known only in the solid state. We report a liquid fluoride ion–conducting electrolyte with high ionic conductivity, wide operating voltage, and robust chemical stability based on dry tetraalkylammonium fluoride salts in ether solvents. Pairing this liquid electrolyte with a copper–lanthanum trifluoride (Cu@LaF_3) core-shell cathode, we demonstrate reversible fluorination and defluorination reactions in a fluoride ion electrochemical cell cycled at room temperature. Fluoride ion–mediated electrochemistry offers a pathway toward developing capacities beyond that of lithium ion technology.

Additional Information

© 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works http://www.sciencemag.org/about/science-licenses-journal-article-reuse. This is an article distributed under the terms of the Science Journals Default License. Received for publication March 28, 2018. Resubmitted August 6, 2018. Accepted for publication October 31, 2018. This work is dedicated to the memory of Nebojša Momčilović. The research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with NASA. V.K.D. thanks the NSF Graduate Research Fellowship Program for support under grant NSF-DGE-1650116. T.F.M. acknowledges NSF under DMREF award NSF-CHE-1335486. M.A.W. acknowledges the Resnick Sustainability Institute. This research used computational resources from the Oak Ridge Leadership Computing Facility at the Oak Ridge National Laboratory, which is supported by the Office of Science of the U.S. Department of Energy (DOE) under contract DE-AC05-00OR22725. This research also used resources of the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility supported by the DOE Office of Science under contract DE-AC02-05CH11231. STEM/EELS work at the Molecular Foundry was supported by the DOE Office of Science, Office of Basic Energy Sciences, under contract DE-AC02-05CH11231. We acknowledge support from the Beckman Institute of the California Institute of Technology to the Molecular Materials Research Center. Author contributions: The project was conceptualized by S.C.J. and supervised by K.O., C.J.B., R.H.G., and S.C.J.; fluoride salt synthesis procedures were developed and performed by V.K.D., C.M.B., N.M., I.M.D., and N.G.N.; salt characterization, analysis and solvent screening was performed by V.K.D., C.M.B., and N.M.; ionic conductivity and voltage window studies were performed by V.K.D. and K.J.B.; PFG-SE NMR experiments and analysis was carried out by W.J.W. and V.K.D.; computational studies were performed by B.M.S. and M.A.W. under the supervision of T.F.M.; electrochemical cells were built and tested by Q.X., N.H.C., and K.O.; cathode materials were synthesized by R.K.M.; TEM, EDS, and pXRD was performed by Q.X.; EELS was performed by S.A., D.R., and M.A.; V.K.D. and A.H. performed XPS measurements; V.K.D. made all figures in the main paper and in the supplement; and the manuscript was written by V.K.D. with input from S.C.J. and all authors. Two patent applications have been filed by Caltech and Honda Motor Co. Ltd.: US 15/228,876 (inventors: S.C.J., V.K.D., C.M.B., N.M., B.M.S., M.A.W., T.F.M., R.H.G., C.J.B., and K.O.) and US 15/844,079 (inventors: N.H.C., K.O., R.K.M., Q.X., C.J.B., S.C.J., I.M.D., and Hongjin Tan). Data and materials availability: Force-field parameters and example inputs for the MD simulations performed are available for download (data S1). All other data are available in the manuscript or the supplementary materials. All authors declare that they have no competing interests.

Attached Files

Supplemental Material - aat7070_Data-S1.zip

Supplemental Material - aat7070_Davis_SM.pdf


Files (3.9 MB)
Name Size Download all
1.4 MB Preview Download
2.5 MB Preview Download

Additional details

August 19, 2023
October 19, 2023