Ceria based solid electrolytes, properties

In the 20 century, many kind of conducting ion species from monovalent to tetravalent ions have been discovered as well as a large number of host crystal lattices. Although some binary rare earth oxides for solid electrolytes have also been investigated, their ion conducting properties were, unfortunately, not enough except the ceria-based materials. 

Mogensen, M., Sammes, N. M., and Tompsett, G. A. (2000). Physical, chemical and electrochemical properties of pure and doped ceria. Solid State Ionics 129 63-94. Godickemeier, M., and Gauckler, L. J. (1998). Engineering of solid oxide fuel cells with ceria-based electrolytes. J Electrochem. Soc. 145 414—421. 

When ceria oxides are used in anode materials in eombination with zireonia-based electrolytes, the calcination temperatures should be set as low as possible to prevent the formation of ceria-zirconia solid solutions which have a lower oxide ion conductivity. The detailed properties of those solid solutions are discussed in section 3.7 concerning the ehemieal stability of SOFC materials. 

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