Ni is widely used as cathode material in molten carbonate fuel cells. Under the extreme conditions the cathode material undergoes dissolution. Addition of LiCoO₂ on the surface of the Ni cathode is known to reduce the precipitation of Ni in the bath [1]. It is also reported that cerium oxide layers reduce nickel oxide dissolution, and catalyse the Li incorporation into the nickel oxide cathode [2]. Therefore there is a strong interest in the electrodeposition of Co/CeO₂ composites for protection of cathodes in MCFC fuel cells.

The application of ultrasound in electrochemistry has become increasingly popular in the past decade, especially in the field of materials science because of its potential in the production of nanomaterials, metals, and metal / oxide composites with superior quality, hardness, and homogeneity [3].

In this context the applicability of the electrochemical quartz crystal microbalance technique (EQCM) in a sonic field created by an ultrasound probe is first time demonstrated for the electrocodeposition of cobalt and nanoscaled cerium oxide particles. For comparison nickel was electrocodeposited with cerium oxide as well. EQCM is based on the measurement of the change in resonance frequency Δf of a thin single-crystalline quartz disc coated with keyhole-shaped gold electrodes on each side in parallel to the electrodeposition. One of the Au electrodes is in contact with the electrolyte and serves as the working electrode. From Δf, mass changes at its surface and therefore deposition rate can be measured with a very high sensitivity.

[1] T. Brenscheidt, F. Nitschke, O. Söllner, and H. Wendt, Electrochim. Acta, 46, 783 (2001)

[2] J. Hoffmann, C.-Y. Yuh and A. Godula Jopek, in Handbook of Fuels Cells, Fundamentals and applications, ed. W. Vielstich, H.A. Gasteiger, Arnold Lamm, Vol. 4, p. 921ff, 2003 John Willey & Sons

[3] R. G. Cornpton, J. C. Eklund, F. Marken: Electroanal., 9, 509 (1997).

• Legal notice:
  

  Copyright (c) Pielaszek Research, all rights reserved.
  The above materials, including auxiliary resources, are subject to Publisher's copyright and the Author(s) intellectual rights. Without limiting Author(s) rights under respective Copyright Transfer Agreement, no part of the above documents may be reproduced without the express written permission of Pielaszek Research, the Publisher. Express permission from the Author(s) is required to use the above materials for academic purposes, such as lectures or scientific presentations.
  In every case, proper references including Author(s) name(s) and URL of this webpage: https://science24.com/paper/11709 must be provided.

1. Doping and structural features of the apatite-type lanthanum silicate in the La2O3–SiO2–Al2O3 and La2O3–SiO2–Fe2O3 systems