The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics

A. Wachter-Welzl, J. Kirowitz, Richard Wagner, S. Smetaczek, G. C. Brunauer, M. Bonta, D. Rettenwander, S. Taibl, A. Limbeck, G. Amthauer, J. Fleig

Research output: Contribution to journalArticleResearchpeer-review

Abstract

All-solid state batteries have the ability to bring us closer to a zero-emission society. Such battery systems, however, require a powerful solid Li-ion conductor with high stability and exceptionally high Li-ion conductivity. Cubic Li7La3Zr2O12 (LLZO) garnets are attractive candidates combining high ionic conductivity and thermal as well as electrochemical stability. Since the cubic LLZO polymorph is not stable at room temperature, supervalent cations, such as Al3+, are needed to stabilize the highly conductive phase. However, strong variations in conductivity values were reported even for very similar Al contents, which is critical for future battery applications. Therefore, the overall performance of 44 samples with nominally identical composition (Li6.40Al0.20La3Zr2O12), sintered at two different temperatures (1150 °C and 1230 °C, respectively) was analysed by electrochemical impedance spectroscopy. The aim of this work is to elucidate the origin of the strong variations in conductivity reported in literature. This study shows that the effective conductivities of the LLZO samples vary between 2 × 10−5 and 8 × 10−4 S cm−1, which cannot be attributed to obvious differences in sample preparation. Furthermore, the stepwise reduction of the sample volume and repeated measuring of the impedance revealed conductivity variations even within a single sample. Finally, preliminary chemical analysis by laser ablation (LA) – inductively coupled plasma (ICP) – mass spectrometry (MS) identified Al inhomogeneities in LLZO, which may be responsible for conductivity variations of nominally equal samples.

Original languageEnglish
Pages (from-to)203-208
Number of pages6
JournalSolid State Ionics
Volume319
DOIs
Publication statusPublished - 1 Jun 2018

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ceramics
Ions
Inductively coupled plasma mass spectrometry
conductivity
Garnets
Laser ablation
Ionic conductivity
Polymorphism
Chemical analysis
Electrochemical impedance spectroscopy
electric batteries
Cations
Positive ions
Temperature
impedance
inductively coupled plasma mass spectrometry
chemical analysis
garnets
ion currents
laser ablation

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Cite this

Wachter-Welzl, A., Kirowitz, J., Wagner, R., Smetaczek, S., Brunauer, G. C., Bonta, M., ... Fleig, J. (2018). The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics. Solid State Ionics, 319, 203-208. https://doi.org/10.1016/j.ssi.2018.01.036

The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics. / Wachter-Welzl, A.; Kirowitz, J.; Wagner, Richard; Smetaczek, S.; Brunauer, G. C.; Bonta, M.; Rettenwander, D.; Taibl, S.; Limbeck, A.; Amthauer, G.; Fleig, J.

In: Solid State Ionics, Vol. 319, 01.06.2018, p. 203-208.

Research output: Contribution to journalArticleResearchpeer-review

Wachter-Welzl, A, Kirowitz, J, Wagner, R, Smetaczek, S, Brunauer, GC, Bonta, M, Rettenwander, D, Taibl, S, Limbeck, A, Amthauer, G & Fleig, J 2018, 'The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics' Solid State Ionics, vol. 319, pp. 203-208. https://doi.org/10.1016/j.ssi.2018.01.036
Wachter-Welzl A, Kirowitz J, Wagner R, Smetaczek S, Brunauer GC, Bonta M et al. The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics. Solid State Ionics. 2018 Jun 1;319:203-208. https://doi.org/10.1016/j.ssi.2018.01.036
Wachter-Welzl, A. ; Kirowitz, J. ; Wagner, Richard ; Smetaczek, S. ; Brunauer, G. C. ; Bonta, M. ; Rettenwander, D. ; Taibl, S. ; Limbeck, A. ; Amthauer, G. ; Fleig, J. / The origin of conductivity variations in Al-stabilized Li7La3Zr2O12 ceramics. In: Solid State Ionics. 2018 ; Vol. 319. pp. 203-208.
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