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Processing and Characterization of Bi 2 O 3 and Sm 2 O 3 Codoped CeO 2 Electrolyte for Intermediate‐Temperature Solid Oxide Fuel Cell
Author(s) -
Zhao Wenguang,
An Shengli,
Ma Liang
Publication year - 2011
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2010.04270.x
Subject(s) - sintering , electrolyte , materials science , conductivity , ionic conductivity , solid oxide fuel cell , microcrystalline , oxide , chemical engineering , ceramic , analytical chemistry (journal) , phase (matter) , fast ion conductor , polarization (electrochemistry) , mineralogy , chemistry , crystallography , composite material , metallurgy , chromatography , electrode , organic chemistry , engineering
A series of ceria‐based solid solution electrolyte, Bi 2 O 3 and Sm 2 O 3 codoped CeO 2 (Sm 0.2− x Bi x Ce 0.8 O 1.9 , x =0, 0.05, 0.10, 0.15, 0.20), were synthesized via a Pechini‐type gel route. The phase composition was analyzed by the X‐ray diffraction. Present study shows that Sm 0.2− x Bi x Ce 0.8 O 1.9 is exceedingly stable as a cubic phase in all temperature range. Starting from the Sm 0.2− x Bi x Ce 0.8 O 1.9 powder with specific surface area of 23.057 m 2 /g and using bismuth oxide as sintering aid, the sintering behavior investigation demonstrates that the Sm 0.2− x Bi x Ce 0.8 O 1.9 green compacts can be densified to nearly theoretical density at 1300°C for 3 h. The very low sintering temperature prevents excessive grain growth during the heating, which is crucial for obtaining microcrystalline ceramics. In the temperature range of 500°–800°C, AC impedance spectra indicate that the Sm 0.2− x Bi x Ce 0.8 O 1.9 has much higher ionic conductivity than SDC (Sm 0.2 Ce 0.8 O 1.9 ), and that the highest conductivity value is 3.982 S/m at 750°C. The increased conductivity implies that the effect of cell volume and polarization, associated with Bi 3+ , played an important role in the anion transport of the materials.