The effect of co-dopant addition on the properties of Ln0.2Ce0.8O2−δ (Ln = Gd, Sm, La) solid-state electrolyte
- 作者：E.Yu. Pikalova ; V.I. Maragou ; A.N. Demina ; A.K. Demin ; P.E. Tsiakaras
- 关键词：Doped ceria ; Electrical conductivity ; Thermal expansion coefficient ; Co-dopant
- 刊名：Journal of Power Sources
- 出版年：2008
- 期刊代码：58_03787753
- 类别：ce
- 出版时间：1 July 2008
- 卷：181
- 期：2
- 页码：199-206
- 文件大小：458 K
摘要
The present work aims at the investigation of Ln0.2Ce0.8O2−<i>δi> (where Ln = Sm, La, Gd) structural and electrical properties when in the Ln sub-lattice, Ba2+ and Sr2+ with ionic radii 1.42 and 1.26 Å, respectively, are introduced. The conductivity measurements were held both in air and in H2 + 3%H2O atmosphere using the 4-probe dc technique at the temperature range of 600–900 °C. Among all the samples, the highest value of electrical conductivity is obtained in the case of (Sm0.75Sr0.2Ba0.05)0.2Ce0.8O2−<i>δi>, both in air and in hydrogen atmosphere. In the case of H2 + 3%H2O the conductivity of the co-doped compounds increases in comparison with air. Moreover, the dependence of conductivity on the oxygen partial pressure, measured at the ion:none; color:black" href="/science?_ob=MathURL&_method=retrieve&_udi=B6TH1-4RTM2YM-9&_mathId=mml1&_user=1067359&_cdi=5269&_rdoc=3&_acct=C000058823&_version=1&_userid=2795313&md5=7e0444abd34494875a4a66b8641be66e" title="Click to view the MathML source" alt="Click to view the MathML source"><i>Pi>O2 range of 0.21–10−22 atm, showed that the electrolytic area of alkaline-earth metals doped Ln0.2Ce0.8O2−<i>δi> is considerably enhanced, as predicted by the theory. Finally, by comparing the thermal expansion coefficients of the different materials (TEC), the thermo-mechanical compatibility between the co-doped and the other cell components was also investigated.