Preparation of Li7P2S8I Solid Electrolyte and Its Application in All-Solid-State Lithium-Ion Batteries with Graphite Anode

  • Tokoharu Yamamoto
  • Nguyen Huu Huy PhucEmail author
  • Hiroyuki Muto
  • Atsunori MatsudaEmail author
Original Article - Energy and Sustainability


A Li7P2S8I solid electrolyte was prepared by the reaction between raw materials in an ethyl propionate medium and drying of the precursor. The obtained sample was characterized by X-ray diffraction (XRD), cyclic voltammetry, DC polarization test and AC impedance measurements. The formation of Li7P2S8I was confirmed from the results of XRD. Cyclic voltammetry and the DC polarization test indicated that the obtained Li7P2S8I was stable at low potential versus Li/Li+ and against Li metal. The all-solid-state lithium-ion battery was fabricated by using Li–In, Li7P2S8I solid electrolyte and a graphite composite that was prepared by mixing graphite, Li7P2S8I solid electrolyte and vapor grown carbon fiber with a vortex mixer. It was observed that the electrode materials were homogeneously mixed from the scanning electron microscopy image of the composite prepared by using the vortex mixer. The fabricated half-cell was characterized by the charge–discharge test. The Li7P2S8I solid electrolyte is suitable for use with a graphite anode because the charge–discharge test exhibited an initial discharge capacity of 372 mA h g−1 and high reversibility of capacity.

Graphical Abstract


Solid electrolyte Green synthesis Graphite anode All-solid-state 



This study was supported by the Advanced Low Carbon Technology Specially Promoted Research for Innovative Next Generation Batteries (JST-ALCA-SPRING) program of the Japan Science and Technology Agency. We thank Edanz Group ( for editing a draft of this manuscript.


  1. 1.
    Bachman, J.C., Muy, S., Grimaud, A., Chang, H.H., Pour, N., Lux, S.F., Paschos, O., Maglia, F., Lupart, S., Lamp, P., Giordano, L., Shao-Horn, Y.: Inorganic solid-state electrolytes for lithium batteries: mechanisms and properties governing ion conduction. Chem. Rev. 116, 140–162 (2016)CrossRefGoogle Scholar
  2. 2.
    Kato, Y., Hori, S., Saito, T., Suzuki, K., Hirayama, M., Mitsui, A., Yonemura, M., Iba, H., Kanno, R.: High-power all-solid-state batteries using sulfide superionic conductors. Nat. Energy 1, 16030 (2016)CrossRefGoogle Scholar
  3. 3.
    Kennedy, J.H., Yang, Y.: Glass-forming region and structure in SiS2–Li2S–LiX (X = Br, I). J. Solid State Chem. 69, 252–257 (1987)CrossRefGoogle Scholar
  4. 4.
    Rangasamy, E., Liu, Z., Gobet, M., Pilar, K., Sahu, G., Zhou, W., Wu, H., Greenbaum, S., Liang, C.: An iodide-based Li7P2S8I superionic conductor. J. Am. Chem. Soc. 137, 1384–1387 (2015)CrossRefGoogle Scholar
  5. 5.
    Suyama, M., Kato, A., Sakuda, A., Hayashi, A., Tatsumisago, M.: Lithium dissolution/deposition behavior with Li3PS4–LiI electrolyte for all-solid-state batteries operating at high temperatures. Electrochem. Acta 286, 158–162 (2018)CrossRefGoogle Scholar
  6. 6.
    Phuc, N.H.H., Morikawa, K., Totani, M., Muto, H., Matsuda, A.: Synthesis of plate-like Li3PS4 solid electrolyte via liquid-phase shaking for all-solid-state lithium batteries. Ionics 23, 2061–2067 (2017)CrossRefGoogle Scholar
  7. 7.
    Takada, K., Inada, T., Kajiyama, A., Sasaki, H., Kondo, S., Watanabe, M., Murayama, M., Kanno, R.: Solid-state lithium battery with graphite anode. Solid State Ion. 158, 269–274 (2003)CrossRefGoogle Scholar
  8. 8.
    Phuc, N.H.H., Hirahara, E., Morikawa, K., Muto, H., Matsuda, A.: One-pot liquid phase synthesis of (100 − x) Li3PS4–xLiI solid electrolytes. J. Power Source 365, 7–11 (2017)CrossRefGoogle Scholar
  9. 9.
    Ito, S., Nakakita, M., Aihara, Y., Uehara, T., Machida, N.: A synthesis of crystalline Li7P3S11 solid electrolyte from 1,2-dimethoxyethane solvent. J. Power Source 271, 342–345 (2014)CrossRefGoogle Scholar
  10. 10.
    Liu, Z., Fu, W., Payzant, E.A., Yu, X., Wu, Z., Dudney, N.J., Kiggans, J., Hong, K., Rondinone, A.J., Liang, C.: Anomalous high ionic conductivity of nanoporous β-Li3PS4. J. Am. Chem. Soc. 135, 975–978 (2013)CrossRefGoogle Scholar
  11. 11.
    Phuc, N.H.H., Yamamoto, T., Muto, H., Matsuda, A.: Fast synthesis of Li2S–P2S5–LiI solid electrolyte precursors. Inorg. Chem. Front. 4, 1660–1664 (2017)CrossRefGoogle Scholar
  12. 12.
    Wang, H., Hood, Z.D., Xia, Y., Liang, C.: Fabrication of ultrathin solid electrolyte membranes of β-Li3PS4 nanoflakes by evaporation-induced self-assembly for all-solid-state batteries. J. Mater. Chem. A 4, 8091–8096 (2016)CrossRefGoogle Scholar
  13. 13.
    Phuc, N.H.H., Morikawa, K., Totani, M., Muto, H., Matsuda, A.: Preparation of Li3PS4 solid electrolyte using ethyl acetate as synthetic medium. Solid State Ion. 288, 240–243 (2016)CrossRefGoogle Scholar
  14. 14.
    Wang, Y., Liu, Z., Zhu, X., Tang, Y., Huang, F.: Highly lithium-ion conductive thio-LISICON thin film processed by low-temperature solution method. J. Power Sources 224, 225–229 (2013)CrossRefGoogle Scholar
  15. 15.
    Zhu, Y., He, X., Mo, Y.: Origin of outstanding stability in the lithium solid electrolyte materials: insights from thermodynamic analyses based on first principles calculations. ACS Appl. Mater. Interfaces 7, 23685–23693 (2015)CrossRefGoogle Scholar
  16. 16.
    Swamy, T., Chen, X., Chiang, Y.-M.: Electrochemical redox behavior of Li ion conducting sulfide solid electrolytes. Chem. Mater. 31, 707–713 (2019)CrossRefGoogle Scholar

Copyright information

© The Korean Institute of Metals and Materials 2019

Authors and Affiliations

  1. 1.Department of Electrical and Electronic Information EngineeringToyohashi University of TechnologyToyohashiJapan

Personalised recommendations