Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Article
  • Published:

Revisiting metal fluorides as lithium-ion battery cathodes

Nature Materials volume 20, pages 841–850 (2021)Cite this article

Subjects

Abstract

Metal fluorides, promising lithium-ion battery cathode materials, have been classified as conversion materials due to the reconstructive phase transitions widely presumed to occur upon lithiation. We challenge this view by studying FeF3 using X-ray total scattering and electron diffraction techniques that measure structure over multiple length scales coupled with density functional theory calculations, and by revisiting prior experimental studies of FeF2 and CuF2. Metal fluoride lithiation is instead dominated by diffusion-controlled displacement mechanisms, and a clear topological relationship between the metal fluoride F− sublattices and that of LiF is established. Initial lithiation of FeF3 forms FeF2 on the particle’s surface, along with a cation-ordered and stacking-disordered phase, A-LixFeyF3, which is structurally related to α-/β-LiMn2+Fe3+F6 and which topotactically transforms to B- and then C-LixFeyF3, before forming LiF and Fe. Lithiation of FeF2 and CuF2 results in a buffer phase between FeF2/CuF2 and LiF. The resulting principles will aid future developments of a wider range of isomorphic metal fluorides.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Electrochemical performance and crystal structures.
Fig. 2: X-ray diffraction and PDF analyses of m-FeF3.
Fig. 3: ED analyses of the partially discharged m-FeF3 ‘Li 0.25’ sample.
Fig. 4: Stacking disorder in A-LixFeyF3.
Fig. 5: X-ray diffraction and PDF of n-FeF3 and illustrated reaction pathways for FeFx.
Fig. 6: Formation of interfacial intermediate upon lithiation of FeF2.

Similar content being viewed by others

Data availability

The authors declare that all data supporting the findings of this study are included within the paper and its Supplementary Information files. Source data are available from the corresponding authors upon reasonable request.

References

  1. Cabana, J., Monconduit, L., Larcher, D. & Palacín, M. R. Beyond intercalation-based Li-ion batteries: the state of the art and challenges of electrode materials reacting through conversion reactions. Adv. Mater. 22, E170–E192 (2010).

    Article  CAS  Google Scholar 

  2. Amatucci, G. G. & Pereira, N. Fluoride based electrode materials for advanced energy storage devices. J. Fluor. Chem. 128, 243–262 (2007).

    Article  CAS  Google Scholar 

  3. Grenier, A. et al. Solid fluoride electrolytes and their composite with carbon: issues and challenges for rechargeable solid state fluoride-ion batteries. J. Phys. Chem. C 121, 24962–24970 (2017).

    Article  CAS  Google Scholar 

  4. Thieu, D. T. et al. CuF2 as reversible cathode for fluoride ion batteries. Adv. Funct. Mater. 27, 1701051 (2017).

    Article  CAS  Google Scholar 

  5. Zhang, L., Anji Reddy, M. & Fichtner, M. Development of tysonite-type fluoride conducting thin film electrolytes for fluoride ion batteries. Solid State Ion. 272, 39–44 (2015).

    Article  CAS  Google Scholar 

  6. Anji Reddy, M. & Fichtner, M. Batteries based on fluoride shuttle. J. Mater. Chem. 21, 17059–17062 (2011).

    Article  CAS  Google Scholar 

  7. Gschwind, F. et al. Fluoride ion batteries: theoretical performance, safety, toxicity, and a combinatorial screening of new electrodes. J. Fluor. Chem. 182, 76–90 (2016).

    Article  CAS  Google Scholar 

  8. Davis, V. K. et al. Room-temperature cycling of metal fluoride electrodes: liquid electrolytes for high-energy fluoride ion cells. Science 362, 1144–1148 (2018).

    Article  CAS  Google Scholar 

  9. Reddy, M. A. & Fichtner, M. in Advanced Fluoride-Based Materials for Energy Conversion (ed. Groult, H.) 51–76 (Elsevier, 2015).

  10. Yamakawa, N., Jiang, M., Key, B. & Grey, C. P. Identifying the local structures formed during lithiation of the conversion material, iron fluoride, in a Li ion battery: a solid-state NMR, X-ray diffraction, and pair distribution function analysis study. J. Am. Chem. Soc. 131, 10525–10536 (2009).

    Article  CAS  Google Scholar 

  11. Zhang, W. et al. In situ electrochemical XAFS studies on an iron fluoride high-capacity cathode material for rechargeable lithium batteries. J. Phys. Chem. C 117, 11498–11505 (2013).

    Article  CAS  Google Scholar 

  12. Kim, S.-W., Seo, D.-H., Gwon, H., Kim, J. & Kang, K. Fabrication of FeF3 nanoflowers on CNT branches and their application to high power lithium rechargeable batteries. Adv. Mater. 22, 5260–5264 (2010).

    Article  CAS  Google Scholar 

  13. Tan, H. J. et al. Electrochemical cycling and lithium insertion in nanostructured FeF3 cathodes. J. Electrochem. Soc. 161, A445–A449 (2014).

    Article  CAS  Google Scholar 

  14. Badway, F., Cosandey, F., Pereira, N. & Amatucci, G. G. Carbon metal fluoride nanocomposites. J. Electrochem. Soc. 150, A1318–A1327 (2003).

    Article  CAS  Google Scholar 

  15. Li, L. et al. Origins of large voltage hysteresis in high-energy-density metal fluoride lithium-ion battery conversion electrodes. J. Am. Chem. Soc. 138, 2838–2848 (2016).

    Article  CAS  Google Scholar 

  16. Liu, P., Vajo, J. J., Wang, J. S., Li, W. & Liu, J. Thermodynamics and kinetics of the Li/FeF3 reaction by electrochemical analysis. J. Phys. Chem. C 116, 6467–6473 (2012).

    Article  CAS  Google Scholar 

  17. Li, L. et al. Visualization of electrochemically driven solid-state phase transformations using operando hard X-ray spectro-imaging. Nat. Commun. 6, 6883 (2015).

    Article  CAS  Google Scholar 

  18. Zhou, M., Zhao, L., Kitajou, A., Okada, S. & Yamaki, J.-I. Mechanism on exothermic heat of FeF3 cathode in Li-ion batteries. J. Power Sources 203, 103–108 (2012).

    Article  CAS  Google Scholar 

  19. Badway, F., Pereira, N., Cosandey, F. & Amatucci, G. G. Carbon-metal fluoride nanocomposites: structure and electrochemistry of FeF3: C. J. Electrochem. Soc. 150, A1209–A1218 (2003).

    Article  CAS  Google Scholar 

  20. Geddes, H. S., Blade, H., McCabe, J. F., Hughes, L. P. & Goodwin, A. L. Structural characterisation of amorphous solid dispersions via metropolis matrix factorisation of pair distribution function data. Chem. Commun. 55, 13346–13349 (2019).

    Article  CAS  Google Scholar 

  21. West, A. R. & Bruce, P. G. Tetragonal-packed crystal structures. Acta Crystallogr. B 38, 1891–1896 (1982).

    Article  Google Scholar 

  22. Yu, H. C. et al. Designing the next generation high capacity battery electrodes. Energy Environ. Sci. 7, 1760–1768 (2014).

    Article  CAS  Google Scholar 

  23. Müller, U. Symmetry Relationships between Crystal Structures: Applications of Crystallographic Group Theory in Crystal Chemistry (Oxford Univ. Press, 2013).

  24. Oszlanyi, G. & Suto, A. Ab initio structure solution by charge flipping. Acta Crystallogr. A 60, 134–141 (2004).

    Article  CAS  Google Scholar 

  25. Rauch, E. et al. Automatic crystal orientation and phase mapping in TEM by precession diffraction. Microsc. Anal. 22, S5–S8 (2008).

    Google Scholar 

  26. Courbion, G., Jacoboni, C. & de Pape, R. The dimorphism of LiMnFeF6: a new kind of cationic order in the structural type Na2SiF6. J. Solid State Chem. 45, 127–134 (1982).

    Article  CAS  Google Scholar 

  27. Doe, R. E., Persson, K. A., Meng, Y. S. & Ceder, G. First-principles investigation of the Li−Fe−F phase diagram and equilibrium and nonequilibrium conversion reactions of iron fluorides with lithium. Chem. Mater. 20, 5274–5283 (2008).

    Article  CAS  Google Scholar 

  28. Goodenough, J. B. & Park, K.-S. The Li-ion rechargeable battery: a perspective. J. Am. Chem. Soc. 135, 1167–1176 (2013).

    Article  CAS  Google Scholar 

  29. Tawa, S., Matsumoto, K. & Hagiwara, R. Reaction pathways of iron trifluoride investigated by operation at 363 K using an ionic liquid electrolyte. J. Electrochem. Soc. 166, A2105–A2110 (2019).

    Article  CAS  Google Scholar 

  30. van der Ven, A., Garikipati, K., Kim, S. & Wagemaker, M. The role of coherency strains on phase stability in LixFePO4: needle crystallites minimize coherency strain and overpotential. J. Electrochem. Soc. 156, A949 (2009).

    Article  CAS  Google Scholar 

  31. Karki, K. et al. Revisiting conversion reaction mechanisms in lithium batteries: lithiation-driven topotactic transformation in FeF2. J. Am. Chem. Soc. 140, 17915–17922 (2018).

    Article  CAS  Google Scholar 

  32. Xiao, A. W. et al. Understanding the conversion mechanism and performance of monodisperse FeF2 nanocrystal cathodes. Nat. Mater. 19, 644–654 (2020).

    Article  CAS  Google Scholar 

  33. Wang, F. et al. Conversion reaction mechanisms in lithium ion batteries: study of the binary metal fluoride electrodes. J. Am. Chem. Soc. 133, 18828–18836 (2011).

    Article  CAS  Google Scholar 

  34. Jain, A. et al. Commentary: the materials project: a materials genome approach to accelerating materials innovation. APL Mater. 1, 011002 (2013).

    Article  CAS  Google Scholar 

  35. Wang, F. et al. Tracking lithium transport and electrochemical reactions in nanoparticles. Nat. Commun. 3, 1201 (2012).

    Article  CAS  Google Scholar 

  36. Wang, F. et al. Ternary metal fluorides as high-energy cathodes with low cycling hysteresis. Nat. Commun. 6, 6668 (2015).

    Article  CAS  Google Scholar 

  37. Cosandey, F., Al-Sharab, J. F., Badway, F., Amatucci, G. G. & Stadelmann, P. EELS spectroscopy of iron fluorides and FeFx/C nanocomposite electrodes used in Li-ion batteries. Microsc. Microanal. 13, 87–95 (2007).

    Article  CAS  Google Scholar 

  38. Sun, Y. et al. In situ chemical synthesis of lithium fluoride/metal nanocomposite for high capacity prelithiation of cathodes. Nano Lett. 16, 1497–1501 (2016).

    Article  CAS  Google Scholar 

  39. Hori, H. & Okada, S. Reconversion reaction of LiF/Fe composite thin film cathodes for lithium-ion battery. Electrochemistry 83, 909–913 (2015).

    Article  CAS  Google Scholar 

  40. Li, T., Chen, Z. X., Ai, X. P., Cao, Y. L. & Yang, H. X. LiF/Fe nanocomposite as a lithium-rich and high capacity conversion cathode material for Li-ion batteries. J. Power Sources 217, 54–58 (2012).

    Article  CAS  Google Scholar 

  41. Hua, X. et al. Comprehensive study of the CuF2 conversion reaction mechanism in a lithium ion battery. J. Phys. Chem. C 118, 15169–15184 (2014).

    Article  CAS  Google Scholar 

  42. Huang, Q. et al. Fading mechanisms and voltage hysteresis in FeF2–NiF2 solid solution cathodes for lithium and lithium-ion batteries. Small 15, 1804670 (2019).

    Article  CAS  Google Scholar 

  43. Pereira, N., Badway, F., Wartelsky, M., Gunn, S. & Amatucci, G. G. Iron oxyfluorides as high capacity cathode materials for lithium batteries. J. Electrochem. Soc. 156, A407 (2009).

    Article  CAS  Google Scholar 

  44. Hammersley, A. FIT2D V9.129 Reference Manual V3.1 ESRF Internal Report 98HA01T (ESRF, 1998).

  45. Basham, M. et al. Data Analysis WorkbeNch (DAWN). J. Synchrotron Radiat. 22, 853–858 (2015).

    Article  Google Scholar 

  46. Qiu, X., Thompson, J. W. & Billinge, S. L. J. PDFgetX2: a GUI-driven program to obtain the pair distribution function from X-ray powder diffraction data. Appl. Crystallogr. 37, 678 (2004).

    Article  CAS  Google Scholar 

  47. Toby, B. H. & von Dreele, R. B. GSAS-II: the genesis of a modern open-source all purpose crystallography software package. J. Appl. Crystallogr. 46, 544–549 (2013).

    Article  CAS  Google Scholar 

  48. Farrow, C. L. et al. PDFfit2 and PDFgui: computer programs for studying nanostructure in crystals. J. Phys. Condens. Matter 19, 335219 (2007).

    Article  CAS  Google Scholar 

  49. Proffen, T. & Neder, R. B. DISCUS, a program for diffuse scattering and defect structure simulations – update. J. Appl. Crystallogr. 32, 838–839 (1999).

    Article  CAS  Google Scholar 

  50. Treacy, M. M. J., Newsam, J. M. & Deem, M. W. A general recursion method for calculating diffracted intensities from crystals containing planar faults. Proc. Math. Phys. Eng. Sci. 433, 499–520 (1991).

    Google Scholar 

  51. Pickard, C. J. & Needs, R. J. High-pressure phases of silane. Phys. Rev. Lett. 97, 045504 (2006).

    Article  CAS  Google Scholar 

  52. Pickard, C. J. & Needs, R. J. Ab initio random structure searching. J. Phys. Condens. Matter 23, 053201 (2011).

    Article  CAS  Google Scholar 

  53. Clark, S. J. et al. First principles methods using CASTEP. Z. Kristallogr. Cryst. Mater. 220, 567–570 (2005).

    Article  CAS  Google Scholar 

  54. Lee, D. D. & Seung, H. S. Learning the parts of objects by non-negative matrix factorization. Nature 401, 788–791 (1999).

    Article  CAS  Google Scholar 

  55. Egami, T. & Billinge, S. J. L. Underneath the Bragg Peaks Structural Analysis of Complex Materials (Pergamon, 2012).

Download references

Acknowledgements

X.H. is supported by funding from the Engineering and Physical Sciences Research Council (EPSRC) Doctoral Prize, Adolphe Merkle and the Swiss National Science Foundation (Program NRP70 no. 153990) and European Commission via Marie Skłodowska-Curie actions (MSCA) (grant 798169). A.S.E. acknowledges financial support from the Royal Society. E.C.-M. acknowledges funding from the European Commission via MSCA (grant 747449) and RTI2018-094550-A-l00 from the Ministerio de Ciencia e Innovación. H.S.G. is supported by EPSRC via Industrial Cooperative Awards in Science and Technology studentship. Z.L. is supported by the Faraday Institution (grant number FIRG017). C.J.P. is supported by the Royal Society through a Royal Society Wolfson Research Merit award and by EPSRC grant EP/P022596/1. A.L.G. acknowledges funding from the European Research Council (grant 788144). This research was supported as part of the North Eastern Center for Chemical Energy Storage, an Energy Frontier Research Center funded by the US Department of Energy, Office of Science, and Office of Basic Energy Sciences under award number DE-SC0001294. Work done at Argonne and use of the Advanced Photon Source, an Office of Science User Facility operated for the US Department of Energy Office of Science by Argonne National Laboratory, was supported by the US Department of Energy under contract no. DE-AC02-06CH11357. Work done at Diamond Light Source was under proposal EE17315-1. We thank G. Ceder and other North Eastern Center for Chemical Energy Storage members for many stimulating discussions concerning fluoride-based conversion reactions and on the origins of structural hysteresis. We also acknowledge help from S. Dutton, T. Dean, A. Docker, M. Leskes and D. Keeble.

Author information

Authors and Affiliations

  1. Department of Chemistry, University of Cambridge, Cambridge, UK

    Xiao Hua, Elizabeth Castillo-Martínez, Rosa Robert, Wei Meng & Clare P. Grey

  2. Adolphe Merkle Institute, Fribourg, Switzerland

    Xiao Hua & Ullrich Steiner

  3. Inorganic Chemistry Laboratory, University of Oxford, Oxford, UK

    Xiao Hua, Harry S. Geddes & Andrew L. Goodwin

  4. Department of Materials Science and Metallurgy, University of Cambridge, Cambridge, UK

    Alexander S. Eggeman, Ziheng Lu, Chris J. Pickard & Paul A. Midgley

  5. Department of Materials, University of Manchester, Manchester, UK

    Alexander S. Eggeman

  6. Departamento Química Inorgánica, Universidad Complutense de Madrid, Madrid, Spain

    Elizabeth Castillo-Martínez

  7. Advanced Institute for Materials Research, Tohoku University, Sendai, Japan

    Chris J. Pickard

  8. X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, IL, USA

    Kamila M. Wiaderek

  9. Energy Storage Research Group, Department of Materials Science and Engineering, Rutgers University, North Brunswick, NJ, USA

    Nathalie Pereira & Glenn G. Amatucci

  10. Department of Chemistry, SUNY Stony Brook, Stony Brook, NY, USA

    Karena W. Chapman

Authors
  1. Xiao Hua
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Alexander S. Eggeman
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Elizabeth Castillo-Martínez
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Rosa Robert
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Harry S. Geddes
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Ziheng Lu
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. Chris J. Pickard
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. Wei Meng
    View author publications

    You can also search for this author in PubMed Google Scholar

  9. Kamila M. Wiaderek
    View author publications

    You can also search for this author in PubMed Google Scholar

  10. Nathalie Pereira
    View author publications

    You can also search for this author in PubMed Google Scholar

  11. Glenn G. Amatucci
    View author publications

    You can also search for this author in PubMed Google Scholar

  12. Paul A. Midgley
    View author publications

    You can also search for this author in PubMed Google Scholar

  13. Karena W. Chapman
    View author publications

    You can also search for this author in PubMed Google Scholar

  14. Ullrich Steiner
    View author publications

    You can also search for this author in PubMed Google Scholar

  15. Andrew L. Goodwin
    View author publications

    You can also search for this author in PubMed Google Scholar

  16. Clare P. Grey
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

X.H., E.C.-M. and R.R. planned the project with C.P.G.; E.C.-M. and R.R. prepared the pristine materials with help from N.P. and G.G.A.; X.H., E.C.-M., R.R. and W.M. performed the electrochemistry tests and prepared samples for ex situ characterization; E.C.-M. and R.R. performed high-resolution X-ray diffraction measurements; A.S.E. acquired and analysed the TEM data with support from P.A.M.; E.C.-M. performed the magnetic measurements and analysed the data; X.H., R.R. and K.M.W. acquired PDF data with support from U.S. and K.W.C.; X.H. performed analyses of the electrochemistry, X-ray diffraction and PDF data; Z.L. and C.J.P. performed the DFT calculations; X.H., H.S.G. and A.L.G. performed the NMF analysis; X.H. and C.P.G. wrote the manuscript with input from all the coauthors.

Corresponding authors

Correspondence to Xiao Hua or Clare P. Grey.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Materials thanks Gleb Yushin and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Extended data

Extended Data Fig. 1 NMR, XRD and PDF results of n-FeF3 in the first cycle.

a) Galvanostatic profile of n-FeF3’s first cycle with distinct reaction processes indicated by different colour backgrounds. The 6Li MAS NMR chemical shifts (red) from our previous study10 are labelled at their respective state of charge with the main phase identification indicated. Black squares mark the states of charge where ex situ X-ray total scattering experiments were performed to acquire b) XRD and c) PDF patterns. Green, blue and pink dotted lines indicate unique Bragg or PDF features from FeF3, LixFeyF3 and FeF2, respectively. The red arrow highlights a drastic decrease in the samples’ particle sizes upon charge. The evolution of the phase mole fractions obtained from the PDF refinement is shown in d) with the deduced step-by-step mechanism diagram indicated on the left, which echoes with the simplified scheme shown in Fig. 5d.

Extended Data Fig. 2 Li-Fe-F phase diagram.

The reference phases in the phase diagram are labelled and indicated by light blue circles so as to show the positions of A- and B-LixFeyF3, whose Fe concentration is off-stoichiometric. The reaction pathways associated with the FeF3 and FeF2 systems are respectively marked by using green and pink dashed arrows. Each reaction process is also labelled with its respective roman numeral used to label the equations in the manuscript.

Supplementary information

Supplementary Information

Supplementary Sections 1–11, Figs. 1–24 and Tables 1 and 2.

Supplementary Video 1

NMF analysis of the discharged FeF2.

Supplementary Video 2

NMF analysis of the discharged CuF2.

Computational Data 1

DFT calculation data.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hua, X., Eggeman, A.S., Castillo-Martínez, E. et al. Revisiting metal fluorides as lithium-ion battery cathodes. Nat. Mater. 20, 841–850 (2021). https://doi.org/10.1038/s41563-020-00893-1

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41563-020-00893-1

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing