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.

Local electronic structure variation resulting in Li ‘filament’ formation within solid electrolytes

Abstract

Solid electrolytes hold great promise for enabling the use of Li metal anodes. The main problem is that during cycling, Li can infiltrate along grain boundaries and cause short circuits, resulting in potentially catastrophic battery failure. At present, this phenomenon is not well understood. Here, through electron microscopy measurements on a representative system, Li7La3Zr2O12, we discover that Li infiltration in solid oxide electrolytes is strongly associated with local electronic band structure. About half of the Li7La3Zr2O12 grain boundaries were found to have a reduced bandgap, around 1–3 eV, making them potential channels for leakage current. Instead of combining with electrons at the cathode, Li+ ions are hence prematurely reduced by electrons at grain boundaries, forming local Li filaments. The eventual interconnection of these filaments results in a short circuit. Our discovery reveals that the grain-boundary electronic conductivity must be a primary concern for optimization in future solid-state battery design.

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

Relevant articles

Open Access articles citing this article.

Access options

Buy article

Get time limited or full article access on ReadCube.

$32.00

All prices are NET prices.

Fig. 1: Atomic and electronic structure difference at the grain bulk and GBs of pristine LLZO.
Fig. 2: The d.c. cycling test of LLZO and microscopy images of LLZO after dendrite penetration.
Fig. 3: In situ TEM observation of the LLZO GB during biasing.
Fig. 4: The structure and chemistry evolution at the grain bulk and GB during biasing.
Fig. 5: Schematic illustrations.

Data availability

The data that support the findings of this study are available from the corresponding authors upon reasonable request.

References

  1. Lin, D., Liu, Y. & Cui, Y. Reviving the lithium metal anode for high-energy batteries. Nat. Nanotechnol. 12, 194–206 (2017).

    CAS  Article  Google Scholar 

  2. Xu, W. et al. Lithium metal anodes for rechargeable batteries. Energy Environ. Sci. 7, 513–537 (2014).

    CAS  Article  Google Scholar 

  3. Albertus, P., Babinec, S., Litzelman, S. & Newman, A. Status and challenges in enabling the lithium metal electrode for high-energy and low-cost rechargeable batteries. Nat. Energy 3, 16–21 (2018).

    CAS  Article  Google Scholar 

  4. Han, F. et al. High electronic conductivity as the origin of lithium dendrite formation within solid electrolytes. Nat. Energy 4, 187–196 (2019).

    CAS  Article  Google Scholar 

  5. Porz, L. et al. Mechanism of lithium metal penetration through inorganic solid electrolytes. Adv. Energy Mater. 7, 1701003 (2017).

    Article  Google Scholar 

  6. Ren, Y., Shen, Y., Lin, Y. & Nan, C. W. Direct observation of lithium dendrites inside garnet-type lithium-ion solid electrolyte. Electrochem. Commun. 57, 27–30 (2015).

    CAS  Article  Google Scholar 

  7. Aguesse, F. et al. Investigating the dendritic growth during full cell cycling of garnet electrolyte in direct contact with Li metal. ACS Appl. Mater. Interfaces 9, 3808–3816 (2017).

    CAS  Article  Google Scholar 

  8. Cheng, E. J., Sharafi, A. & Sakamoto, J. Intergranular Li metal propagation through polycrystalline Li6.25Al0.25La3Zr2O12 ceramic electrolyte. Electrochim. Acta 223, 85–91 (2017).

    CAS  Article  Google Scholar 

  9. Sharafi, A., Meyer, H. M., Nanda, J., Wolfenstine, J. & Sakamoto, J. Characterizing the Li–Li7La3Zr2O12 interface stability and kinetics as a function of temperature and current density. J. Power Sources 302, 135–139 (2016).

    CAS  Article  Google Scholar 

  10. Ma, C. et al. Interfacial stability of Li metal–solid electrolyte elucidated via in situ electron microscopy. Nano Lett. 16, 7030–7036 (2016).

    CAS  Article  Google Scholar 

  11. Cheng, L. et al. The origin of high electrolyte–electrode interfacial resistances in lithium cells containing garnet type solid electrolytes. Phys. Chem. Chem. Phys. 16, 18294–18300 (2014).

    CAS  Article  Google Scholar 

  12. Zhu, Y., He, X. & Mo, Y. First principles study on electrochemical and chemical stability of solid electrolyte–electrode interfaces in all-solid-state Li-ion batteries. J. Mater. Chem. A 4, 3253–3266 (2016).

    CAS  Article  Google Scholar 

  13. Hofstetter, K., Samson, A. J., Narayanan, S. & Thangadurai, V. Present understanding of the stability of Li-stuffed garnets with moisture, carbon dioxide, and metallic lithium. J. Power Sources 390, 297–312 (2018).

    CAS  Article  Google Scholar 

  14. Li, Y. et al. Garnet electrolyte with an ultralow interfacial resistance for Li-metal batteries. J. Am. Chem. Soc. 140, 6448–6455 (2018).

    CAS  Article  Google Scholar 

  15. Yu, S. et al. Elastic properties of the solid electrolyte Li7La3Zr2O12 (LLZO). Chem. Mater. 28, 197–206 (2016).

    CAS  Article  Google Scholar 

  16. Ni, J. E., Case, E. D., Sakamoto, J. S., Rangasamy, E. & Wolfenstine, J. B. Room temperature elastic moduli and Vickers hardness of hot-pressed LLZO cubic garnet. J. Mater. Sci. 47, 7978–7985 (2012).

    CAS  Article  Google Scholar 

  17. Shen, F., Dixit, M. B., Xiao, X. & Hatzell, K. B. Effect of pore connectivity on Li dendrite propagation within LLZO electrolytes observed with synchrotron X-ray tomography. ACS Energy Lett. 3, 1056–1061 (2018).

    CAS  Article  Google Scholar 

  18. Suzuki, Y. et al. Transparent cubic garnet-type solid electrolyte of Al2O3-doped Li7La3Zr2O12. Solid State Ion. 278, 172–176 (2015).

    CAS  Article  Google Scholar 

  19. Sudo, R. et al. Interface behavior between garnet-type lithium-conducting solid electrolyte and lithium metal. Solid State Ion. 262, 151–154 (2014).

    CAS  Article  Google Scholar 

  20. Duan, H., Zheng, H., Zhou, Y., Xu, B. & Liu, H. Stability of garnet-type Li ion conductors: an overview. Solid State Ion. 318, 45–53 (2018).

    CAS  Article  Google Scholar 

  21. Yang, C. et al. Continuous plating/stripping behavior of solid-state lithium metal anode in a 3D ion-conductive framework. Proc. Natl Acad. Sci. USA 115, 3770–3775 (2018).

    CAS  Article  Google Scholar 

  22. Wu, B. et al. The role of the solid electrolyte interphase layer in preventing Li dendrite growth in solid-state batteries. Energy Environ. Sci. 11, 1803–1810 (2018).

    CAS  Article  Google Scholar 

  23. Fu, K. K. et al. Toward garnet electrolyte–based Li metal batteries: an ultrathin, highly effective, artificial solid-state electrolyte/metallic Li interface. Sci. Adv. 3, e1601659 (2017).

    Article  Google Scholar 

  24. Sharafi, A. et al. Surface chemistry mechanism of ultra-low interfacial resistance in the solid-state electrolyte Li7La3Zr2O12. Chem. Mater. 29, 7961–7968 (2017).

    CAS  Article  Google Scholar 

  25. Tsai, C. L. et al. Li7La3Zr2O12 interface modification for Li dendrite prevention. ACS Appl. Mater. Interfaces 8, 10617–10626 (2016).

    CAS  Article  Google Scholar 

  26. Wu, B. et al. The role of the solid electrolyte interphase layer in preventing Li dendrite growth in solid-state batteries. Energy Environ. Sci. 11, 1803–1810 (2018).

    CAS  Article  Google Scholar 

  27. Tian, H. K., Liu, Z., Ji, Y., Chen, L. Q. & Qi, Y. Interfacial electronic properties dictate Li dendrite growth in solid electrolytes. Chem. Mater. 31, 7351–7359 (2019).

    CAS  Article  Google Scholar 

  28. Yu, S. & Siegel, D. J. Grain boundary contributions to Li-ion transport in the solid electrolyte Li7La3Zr2O12 (LLZO). Chem. Mater. 29, 9639–9647 (2017).

    CAS  Article  Google Scholar 

  29. Hachtel, J. A., Lupini, A. R. & Idrobo, J. C. Exploring the capabilities of monochromated electron energy loss spectroscopy in the infrared regime. Sci. Rep. 8, 5637 (2018).

    Article  Google Scholar 

  30. Zhan, W. et al. Nanoscale mapping of optical band gaps using monochromated electron energy loss spectroscopy. Nanotechnology 28, 105703 (2017).

    CAS  Article  Google Scholar 

  31. Tizei, L. H. G. et al. Exciton mapping at subwavelength scales in two-dimensional materials. Phys. Rev. Lett. 114, 107601 (2015).

    Article  Google Scholar 

  32. Thompson, T. et al. Electrochemical window of the Li-ion solid electrolyte Li7La3Zr2O12. ACS Energy Lett. 2, 462–468 (2017).

    CAS  Article  Google Scholar 

  33. Bean, J. J. et al. Atomic structure and electronic properties of MgO grain boundaries in tunnelling magnetoresistive devices. Sci. Rep. 7, 45594 (2017).

    CAS  Article  Google Scholar 

  34. Chisholm, M. F. et al. Electronic structure of a grain-boundary model in SrTiO3. Phys. Rev. B 60, 2416–2424 (1999).

    Article  Google Scholar 

  35. Guhl, H. et al. Structural and electronic properties of Σ7 grain boundaries in α-Al2O3. Acta Mater. 99, 16–28 (2015).

    CAS  Article  Google Scholar 

  36. Rangasamy, E., Wolfenstine, J. & Sakamoto, J. The role of Al and Li concentration on the formation of cubic garnet solid electrolyte of nominal composition Li7La3Zr2O12. Solid State Ion. 206, 28–32 (2012).

    CAS  Article  Google Scholar 

  37. Knauth, P. Inorganic solid Li ion conductors: an overview. Solid State Ion. 180, 911–916 (2009).

    CAS  Article  Google Scholar 

  38. Ma, C. et al. Atomic-scale origin of the large grain-boundary resistance in perovskite Li-ion-conducting solid electrolytes. Energy Environ. Sci. 7, 1638–1642 (2014).

    CAS  Article  Google Scholar 

  39. Lazar, S., Botton, G. A., Wu, M.-Y., Tichelaar, F. D. & Zandbergen, H. W. Materials science applications of HREELS in near edge structure analysis and low-energy loss spectroscopy. Ultramicroscopy 96, 535–546 (2003).

    CAS  Article  Google Scholar 

  40. Park, J. & Yang, M. Determination of complex dielectric functions at HfO2/Si interface by using STEM-VEELS. Micron 40, 365–369 (2009).

    CAS  Article  Google Scholar 

Download references

Acknowledgements

This work was initiated as part of a project supported by the US Department of Energy (DOE), Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division. Technique developments and M.C.’s efforts on analysis and manuscript preparation were supported by DOE Basic Energy Sciences early career award no. ERKCZ55. Microscopy was conducted at Oak Ridge National Laboratory’s Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. A.S. and J.S. acknowledge support from the DOE Advanced Battery Material Research programme grant no. DE-EE00006821. Y.C. acknowledges computing resources made available through the VirtuES project, funded by Laboratory Directed Research and Development programme and Compute and Data Environment for Science (CADES). C.M. acknowledges support from the National Key R&D Program of China (2018YFA0209600, 2017YFA0208300), the National Natural Science Foundation of China (51802302) and the Fundamental Research Funds for the Central Universities (WK2060190085, WK3430000006). M.C. thanks R. Erni at ETH Zurich for the valuable discussions on valence-EELS analysis. Part of the research was conducted using instrumentation within ORNL’s Materials Characterization Core provided by UT-Batelle under contract no. DE-AC05-00OR22725 with the DOE.

Author information

Authors and Affiliations

Authors

Contributions

M.C. conceived the study. X.L. performed the TEM, EELS, SEM and EDX. R.G.-M., A.S. and J.S. performed the LLZO synthesis, electrochemical measurements and electron backscatter diffraction. A.R.L., J.C.I. and M.C. performed the valence-EELS experiments and carried out the related analysis. C.W. and F.H. performed SEM characterizations. Y.C. performed density functional theory calculations. M.C., C.W., C.M., Y.C. and J.S. interpreted the results. C.M. and X.L. wrote the manuscript. All authors contributed to the discussion of the results and the manuscript editing.

Corresponding authors

Correspondence to Cheng Ma, Jeff Sakamoto or Miaofang Chi.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Materials thanks the anonymous reviewers 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.

Supplementary information

Supplementary Information

Supplementary Figs. 1–9.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Liu, X., Garcia-Mendez, R., Lupini, A.R. et al. Local electronic structure variation resulting in Li ‘filament’ formation within solid electrolytes. Nat. Mater. 20, 1485–1490 (2021). https://doi.org/10.1038/s41563-021-01019-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41563-021-01019-x

Further reading

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