Interface instability of Fe-stabilized Li7La3Zr2O12 versus li metal

Daniel Rettenwander*, Reinhard Wagner, Andreas Reyer, Maximilian Bonta, Lei Cheng, Marca M. Doeff, Andreas Limbeck, Martin Wilkening, Georg Amthauer

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

The interface stability versus Li represents a major challenge in the development of next-generation all-solid-state batteries (ASSB), which take advantage of the inherently safe ceramic electrolytes. Cubic Li7La3Zr2O12 garnets represent the most promising electrolytes for this technology. The high interfacial impedance versus Li is, however, still a bottleneck toward future devices. Herein, we studied the electrochemical performance of Fe3+-stabilized Li7La3Zr2O12 (LLZO:Fe) versus Li metal and found a very high total conductivity of 1.1 mS cm-1 at room temperature but a very high area specific resistance of 1 k cm2. After removing the Li metal electrode we observe a black surface coloration at the interface, which clearly indicates interfacial degradation. Raman- and nanosecond laser-induced breakdown spectroscopy reveals, thereafter, the formation of a 130 μm thick tetragonal LLZO interlayer and a significant Li deficiency of about 1-2 formula units toward the interface. This shows that cubic LLZO:Fe is not stable versus Li metal by forming a thick tetragonal LLZO interlayer causing high interfacial impedance.

Original languageEnglish
Pages (from-to)3780-3785
Number of pages6
JournalThe Journal of Physical Chemistry / C
Volume122
Issue number7
DOIs
Publication statusPublished - 22 Feb 2018

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Physical and Theoretical Chemistry
  • Surfaces, Coatings and Films

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    Rettenwander, D., Wagner, R., Reyer, A., Bonta, M., Cheng, L., Doeff, M. M., ... Amthauer, G. (2018). Interface instability of Fe-stabilized Li7La3Zr2O12 versus li metal. The Journal of Physical Chemistry / C, 122(7), 3780-3785. https://doi.org/10.1021/acs.jpcc.7b12387