The Ionic Diffusion Model for the Solid Oxide Cathode and Its Verification by the Electrolysis of Ta₂O₅ in Molten CaCl₂

Authors

Hua-lin CHEN, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
Zhi-yong WANG, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;
Xian-bo JIN, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;Follow
George Z. Chen, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, China;Department of Chemical and Environmental Engineering, and Energy and Sustainability Research Division, Faculty of Engineering, University of Nottingham, Nottingham NG7 2RD, UK;

Corresponding Author

Xian-bo JIN(xbjin@whu.edu.cn)

Abstract

The deoxidation speed of a solid oxide cathode in molten CaCl₂ can be estimated by the PRS steady diffusion model of O^2-, which correlates the deoxidation speed with the precursor porosity, P, the metal-to-oxide molar volume ratio, R, and the cathode volume shrinkage S. The PRS model indicates that the porosity of the oxide cathode has important influence on the deoxidation speed, and provides a very simple equation for the prediction of the optimal cathode porosity. For the electrolysis of Ta₂O₅, the porosity of the cathode is better to be within 50%. The model and its predictions has been well verified by the electrolysis of solid Ta₂O₅ in molten CaCl₂, suggesting the great significance of the PRS model for the high speed and high current efficiency electrolysis of solid compound cathode in molten salts.

Graphical Abstract

DOI Link

https://doi.org/10.13208/j.electrochem.130886

Publication Date

2014-06-28

Online Available Date

2013-11-11

Revised Date

2013-11-06

Received Date

2013-09-02

Recommended Citation

Hua-lin CHEN, Zhi-yong WANG, Xian-bo JIN, George Z. Chen. The Ionic Diffusion Model for the Solid Oxide Cathode and Its Verification by the Electrolysis of Ta₂O₅ in Molten CaCl₂[J]. Journal of Electrochemistry, 2014 , 20(3): 266-271.
DOI: 10.13208/j.electrochem.130886
Available at: https://jelectrochem.xmu.edu.cn/journal/vol20/iss3/8