Skip to main content

Dramatic reduction in the densification temperature of garnet-type solid electrolytes


Cubic garnet Li7La3Zr2O12 (LLZO) and similar compositions of fast ion-conducting solid-state electrolytes have shown great potential for the development of high-energy-density solid-state Li-ion batteries. Although these materials have shown unprecedented ionic conductivities and chemical stability, these materials require high processing temperatures for synthesis. For many of the common compositions of LLZO, temperatures above 1000 °C are required to form the cubic garnet phase and to achieve high conductivities. Therefore, lowering the processing temperatures of these materials is of great interest for the purposes of scalability and fabrication. It has been reported that a Bi co-dopant not only stabilizes the cubic garnet phase but also lowers the densification temperature. In this study, Li6La3ZrBiO12 (LLZBO) was prepared by a rapid-induction hot-pressing technique and characterized using a variety of techniques, including X-ray diffraction, scanning electron microscopy, and Raman spectroscopy. We demonstrate the ability to synthesize phase-pure LLZBO with higher relative densities (~ 94%) than can be achieved by pressure-less sintering methods, at pressing temperatures of only 850 °C. The ionic conductivity was measured to be 0.1 mS cm−1, which is comparable to the best reported conductivities of high-density LLZO. This demonstrates the ability to fabricate dense, phase-pure, and high-conductivity LLZBO at temperatures significantly lower than other garnet compositions, which will prove useful for scalability and reducing reactivity with cathodes during densification.

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7


  1. Murugan R, Thangadurai V, Weppner W (2007) Fast lithium ion conduction in garnet-type Li7La3Zr2O12. Angew Chem Int Ed 46(41):7778–7781.

    Article  CAS  Google Scholar 

  2. Thangadurai V, Narayanan S, Pinzaru D (2014) Garnet-type solid-state fast Li ion conductors for Li batteries: critical review. Chem Soc Rev 43(13):4714–4727.

    Article  CAS  PubMed  Google Scholar 

  3. Thompson T, Sharafi A, Johannes MD et al (2015) A tale of two sites: on defining the carrier concentration in garnet-based ionic conductors for advanced Li batteries. Adv Energy Mater 5(11):1500096.

    Article  CAS  Google Scholar 

  4. Tarascon J-M, Armand M (2001) Issues and challenges facing rechargeable lithium batteries. Nature 414(6861):359–367.

    Article  CAS  PubMed  Google Scholar 

  5. Goodenough JB, Kim Y (2010) Challenges for rechargeable Li batteries . Chem Mater 22(3):587–603.

    Article  CAS  Google Scholar 

  6. Allen JL, Wolfenstine J, Rangasamy E, Sakamoto J (2012) Effect of substitution (Ta, Al, Ga) on the conductivity of Li7La3Zr2O12. J Power Sources 206:315–319.

    Article  CAS  Google Scholar 

  7. Miara LJ, Ong SP, Mo Y, Richards WD, Park Y, Lee JM, Lee HS, Ceder G (2013) Effect of Rb and Ta doping on the ionic conductivity and stability of the garnet Li7 + 2x − y(La3 − xRbx)(Zr2 − yTay)O12 (0 ≤ x ≤ 0.375, 0 ≤ y ≤ 1) superionic conductor: a first principles investigation. Chem Mater 25(15):3048–3055.

    Article  CAS  Google Scholar 

  8. Rangasamy E, Wolfenstine J, Allen J, Sakamoto J (2013) The effect of 24c-site (A) cation substitution on the tetragonal–cubic phase transition in Li7 − xLa3 − xAxZr2O12 garnet-based ceramic electrolyte. J Power Sources 230:261–266.

    Article  CAS  Google Scholar 

  9. Thompson T, Wolfenstine J, Allen JL et al (2014) Tetragonal vs. cubic phase stability in Al—free Ta doped Li7La3Zr2O12 (LLZO). J Mater Chem A 2(33):13431–13436.

    Article  CAS  Google Scholar 

  10. Xia Y, Ma L, Lu H, Wang XP, Gao YX, Liu W, Zhuang Z, Guo LJ, Fang QF (2015) Preparation and enhancement of ionic conductivity in Al-added garnet-like Li6.8La3Zr1.8Bi0.2O12 lithium ionic electrolyte. Front Mater Sci 9(4):366–372.

    Article  Google Scholar 

  11. Teng S, Tan J, Tiwari A (2014) Recent developments in garnet based solid state electrolytes for thin film batteries. Curr Opin Solid State Mater Sci 18(1):29–38.

    Article  CAS  Google Scholar 

  12. Murugan R, Weppner W, Schmid-Beurmann P, Thangadurai V (2007) Structure and lithium ion conductivity of bismuth containing lithium garnets Li5La3Bi2O12 and Li6SrLa2Bi2O12. Mater Sci Eng B 143(1-3):14–20.

    Article  CAS  Google Scholar 

  13. Gao YX, Wang XP, Wang WG, Zhuang Z, Zhang DM, Fang QF (2010) Synthesis, ionic conductivity, and chemical compatibility of garnet-like lithium ionic conductor Li5La3Bi2O12. Solid State Ionics 181(31-32):1415–1419.

    Article  CAS  Google Scholar 

  14. Peng H, Xiao L, Cao Y, Luan X (2015) Synthesis and ionic conductivity of Li6La3BiSnO12 with cubic garnet-type structure via solid-state reaction. J Cent South Univ 22(8):2883–2886.

    Article  CAS  Google Scholar 

  15. Peng H, Zhang Y, Li L, Feng L (2017) Effect of quenching method on Li ion conductivity of Li5La3Bi2O12 solid state electrolyte. Solid State Ionics 304:71–74.

    Article  CAS  Google Scholar 

  16. Wagner R, Rettenwander D, Redhammer GJ et al (2016) Synthesis, crystal structure, and stability of cubic Li7 − xLa3Zr2 − xBixO12. Inorg Chem 55(23):12211–12219.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  17. Schwanz DKW (2016) Solution based processing of garnet type oxides for optimized lithium-ion transport. Dissertation, Purdue University

  18. Schwanz DK, Marinero-Caceres EE (2016) Solid-state electrolytes and batteries made therefrom, and methods of making solid-state electrolytes. In: Google Pat. Accessed 28 Jan 2018

  19. David IN, Thompson T, Wolfenstine J et al (2015) Microstructure and Li-ion conductivity of hot-pressed cubic Li7La3Zr2O12. J Am Ceram Soc 98(4):1209–1214.

    Article  CAS  Google Scholar 

  20. Kim Y, Jo H, Allen JL et al (2016) The effect of relative density on the mechanical properties of hot-pressed cubic Li7La3Zr2O12. J Am Ceram Soc 99(4):1367–1374.

    Article  CAS  Google Scholar 

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

    Article  CAS  Google Scholar 

  22. Caslavsky JL, Viechnicki DJ (1980) Melting behaviour and metastability of yttrium aluminium garnet (YAG) and YAlO3 determined by optical differential thermal analysis. J Mater Sci 15(7):1709–1718.

    Article  CAS  Google Scholar 

  23. Xiao Q, Derby JJ (1994) Heat transfer and interface inversion during the Czochralski growth of yttrium aluminum garnet and gadolinium gallium garnet. J Cryst Growth 139(1-2):147–157.

    Article  CAS  Google Scholar 

  24. Huggins RA (2002) Simple method to determine electronic and ionic components of the conductivity in mixed conductors a review. Ionics 8(3-4):300–313.

    Article  CAS  Google Scholar 

  25. Irvine JTS, Sinclair DC, West AR (1990) Electroceramics: characterization by impedance spectroscopy. Adv Mater 2(3):132–138.

    Article  CAS  Google Scholar 

  26. Wolfenstine J, Ratchford J, Rangasamy E et al (2012) Synthesis and high Li-ion conductivity of Ga-stabilized cubic Li7La3Zr2O12. Mater Chem Phys 134(2-3):571–575.

    Article  CAS  Google Scholar 

  27. Thompson T, Yu S, Williams L, Schmidt RD, Garcia-Mendez R, Wolfenstine J, Allen JL, Kioupakis E, Siegel DJ, Sakamoto J (2017) Electrochemical window of the Li-ion solid electrolyte Li7La3Zr2O12. ACS Energy Lett 2(2):462–468.

    Article  CAS  Google Scholar 

Download references


This work was supported by the Ford Motor Company Alliance Program.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Jeff Sakamoto.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Wang, M., Sakamoto, J. Dramatic reduction in the densification temperature of garnet-type solid electrolytes. Ionics 24, 1861–1868 (2018).

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:


  • Solid-state electrolyte
  • Hot-pressing
  • Low densification temperature
  • Garnet