Visualization of TiO2 Reduction Behavior in Molten Salt Electrolysis


An in situ observation technique of the TiO2 interfacial behavior in molten LiCl-KCl electrolysis was developed. The variation of the thin TiO2 electrode surface were tracked through the high-speed digital microscopy synchronized with the electrochemical measurement. Two characteristic interfacial behaviors were discovered: physical breakage of the titanium oxide and Li(l) spreading on electrode surface. These electrochemically induced interfacial behaviors affect the current-time curves due to the heterogeneity of the titanium oxide film shape.

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

Fig. 1
Fig. 2
Fig. 3
Fig. 4


  1. 1.

    G. Z. Chen, D. J. Fray and T. W. Farthing: Nature, 2000, vol. 407, pp. 361–64.

    CAS  Article  Google Scholar 

  2. 2.

    K. Ono, and R. O. Suzuki: JOM, 2002, vol. 54, pp. 59–61.

    CAS  Article  Google Scholar 

  3. 3.

    R. O. Suzuki, and S. Inoue, Metall. Mater. Trans. B, 2003, vol. 34, pp. 277–85.

    CAS  Article  Google Scholar 

  4. 4.

    R. O. Suzuki, H. Noguchi, H. Hada, S. Natsui, and T. Kikuchi: Mater. Trans., 2017, vol. 58, pp. 341–349.

    CAS  Article  Google Scholar 

  5. 5.

    H. Noguchi, S. Natsui, T. Kikuchi, and R. O. Suzuki: Electrochem., 2018, vol. 86, pp. 82–87.

    CAS  Article  Google Scholar 

  6. 6.

    J. M. Hur, S. C. Lee, S. M. Jeong, and C. S. Seo: Chem. Lett., 2007, vol.36, pp.1028-29.

    CAS  Article  Google Scholar 

  7. 7.

    M. W. Lee, E. Y. Choi, S. C. Jeon, J. Lee, S. B. Park, S. Paek, M. F. Simpson, S. M. Jeong: Electrochem. Commun., 2016, vol. 72, pp.23-26.

    CAS  Article  Google Scholar 

  8. 8.

    Y. Sakamura: J. Electrochem. Soc., 2010, vol. 157, pp. E135–E139.

    CAS  Article  Google Scholar 

  9. 9.

    Y. Katayama and B. Friedrich: Electrochem. Soc. Proc., 2004, vol. 2004, pp. 1046-51.

    Google Scholar 

  10. 10.

    S. Natsui, T. Sudo, T. Kikuchi, and R. O. Suzuki: Electrochem. Commun., 2017, vol.81, pp. 43-47.

    CAS  Article  Google Scholar 

  11. 11.

    T. Takenaka, S. Akimura, and T. Morishige: Electrochem., 2018, vol. 86, pp. 179-83.

    CAS  Article  Google Scholar 

  12. 12.

    W. Xiao, X. Jin, Y. Deng, D. Wang, and G. Z. Chen: J. Electroanal. Chem., 2010, vol. 639(1-2), pp. 130-140.

    CAS  Article  Google Scholar 

  13. 13.

    W. Xiao, X. Jin, Y. Deng, D. Wang, X. Hu, and G. Z. Chen: ChemPhysChem, 2006, vol. 7(8), 1750-1758.

    CAS  Article  Google Scholar 

  14. 14.

    Y. Deng, D. Wang, W. Xiao, X. Jin, X. Hu, and G. Z. Chen: The J. Phys. Chem. B, 2005, vol. 109(29), 14043-14051.

    CAS  Article  Google Scholar 

  15. 15.

    S. Natsui, T. Sudo, T. Kaneko, K. Tonya, D. Nakajima, T. Kikuchi, and R. O. Suzuki: Sci. Rep., 2018, vol. 8, pp. 13114.

    Article  Google Scholar 

  16. 16.

    Y. Sakamura, M. Kurata, and T. Inoue: J. Electrochem. Soc., 2006 vol. 153, pp. D31-D39.

    CAS  Article  Google Scholar 

  17. 17.

    H. Kuma, K. Ito, and M. Kawakami: Tetsu-to-Hagane, 1990, vol. 76, pp. 1656-63.

    CAS  Article  Google Scholar 

  18. 18.

    P. Lai, M. Hu, Z. Qu, L. Gao, C. Bai, T. Wang, S. Zhang, and G. Qiu, Metall. Mater. Trans. B, 2018, vol. 49, pp. 3403-3412.

    Article  Google Scholar 

  19. 19.

    K. S. Mohandas, and D. J. Fray: Trans. Indian Inst. Met., 2004, vol. 57, pp. 579-92.

    CAS  Google Scholar 

  20. 20.

    R. C. DeVries, and R. Roy: Am. Ceram. Soc. Bull., 1954, vol. 33, pp. 370-72.

    CAS  Google Scholar 

Download references

This work was made possible by the financial support from the Grant-in-Aid for Scientific Research (KAKENHI Grant No. 18K14036), the Iketani Science and Technology Foundation (Grant No. 0291073-A), Tanikawa Fund Promotion of Thermal Technology, and Amano Institute of Technology.

Author information



Corresponding author

Correspondence to Shungo Natsui.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Manuscript submitted May 12, 2019.

Electronic supplementary material

Below is the link to the electronic supplementary material.

Supplementary material 1 (AVI 71287 kb)

Supplementary material 2 (AVI 75494 kb)

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Natsui, S., Sudo, T., Shibuya, R. et al. Visualization of TiO2 Reduction Behavior in Molten Salt Electrolysis. Metall Mater Trans B 51, 11–15 (2020).

Download citation