Abstract
The oxygen reduction mechanism was investigated in carbonate melts of variable composition ranging from the eutectics Li–K, Li–Na to ternary Li–Na–K melts. The effect of pressure on electrode kinetics was also examined. Cyclic voltammetry, convolution voltammetry and electrochemical impedance spectroscopy have shown that oxygen reduction is mass-transfer limited in all melt compositions investigated. It was also found that pressurizing increased the concentration of oxygen electroactive species. To gain information about the reaction mechanism, the impedance spectra have been fitted to four possible equivalents circuits: (i) Randles circuit, (ii) Randles circuit extended by a parallel RC circuit due to film formation, (iii) Gerisher (homogeneous reaction) impedance, and (iv) Modified Randles circuit. The discussion of the results is based on careful analysis of fit quality and meaningfulness of fit parameters.
Similar content being viewed by others
References
A.J. Appleby and S.B. Nicholson, J. Electroanal. Chem. 112 (1980) 71.
K. Yamada, T. Nishina, I. Uchida and J.R. Selman, Electrochim. Acta 38 (1993) 2405.
G.B. Dunks and D. Stelman, Inorg. Chem. 22 (1983) 2168.
R. Makkus, Doctoral thesis, Delft University of Technology, Delft, The Netherlands (1991).
M. Cassir, B. Malinowska, W. Peelen, K. Hemmmes and J.H.W. de Wit, J. Electroanal. Chem. 433 (1997) 195.
I. Uchida, T. Nishina, Y. Mugikura and K. Itaya, J. Electroanal. Chem. 206 (1986) 229.
I. Uchida, Y. Mugikura, T. Nishina and K. Itaya, J. Electroanal. Chem. 206 (1986) 241.
I. Uchida, T. Nishina, Y. Mugikura and K. Itaya, J. Electroanal. Chem. 209 (1986) 125.
K.B. Oldham, J. Electroanal. Chem. 121 (1981) 341.
B.A. Boukamp, 'Equivalent Circuit User' Manual' (University of Twente, 1989).
A.J. Appleby and S. Nicholson, J. Electroanal. Chem. 53 (1974) 105.
A.J. Appleby and S.B. Nicholson, J. Electroanal. Chem. 83 (1977) 309.
B.B. Dave, R.E. White, S. Srinivasan and A.J. Appleby, J. Electrochem. Soc. 138 (1991) 673.
M. Greness and K.B. Oldham, Anal. Chem. 44 (1972) 1121.
T. Nishina, I. Uchida and J.R. Selman, J. Electrochem. Soc. 141 (1994) 1191.
M. Matsumura and J.R. Selman, J. Electrochem. Soc. 139 (1992) 1255.
C-G. Lee, K. Yamada, T. Nishina and I. Uchida, J. Electrochem. Soc. 143 (1996) 2315.
M. Mohamedi, Y. Hisamitsu, Y. Ono, T. Itoh and I. Uchida, J. Electrochem. Soc. 147 (2000) 490.
B.A. Boukamp, J. Electrochem. Soc. 142 (1995) 1885.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Mohamedi, M., Hisamitsu, Y., Ono, Y. et al. Effect of molten carbonate composition on oxygen reduction under pressurized conditions: cyclic voltammetry and equivalent circuit analysis. Journal of Applied Electrochemistry 30, 1397–1404 (2000). https://doi.org/10.1023/A:1026539032082
Issue Date:
DOI: https://doi.org/10.1023/A:1026539032082