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Preparation and Characterization of Samaria‐Doped Ceria Electrolyte Materials for Solid Oxide Fuel Cells
Author(s) -
Fu YenPei,
Wen ShawBing,
Lu ChiHua
Publication year - 2008
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.1551-2916.2007.01923.x
Subject(s) - materials science , crystallite , coprecipitation , ceramic , ionic conductivity , solid oxide fuel cell , grain size , analytical chemistry (journal) , microstructure , mineralogy , solid solution , dopant , oxide , doping , electrolyte , chemical engineering , composite material , metallurgy , chemistry , chromatography , engineering , electrode , optoelectronics
The microstructure, thermal expansion, mechanical property, and ionic conductivity of samaria‐doped ceria (SDC) prepared by coprecipitation were investigated in this paper. The results revealed that the average particle size ranged from 10.9±0.4 to 13.5±0.5 nm, crystallite dimension varied from 8.6±0.3 to 10.7±0.4 nm, and the specific surface area distribution ranged from 62.6±1.8 to 76.7±2.2 m 2 /g for SDC powders prepared by coprecipitation. The dependence of lattice parameter, a, versus dopant concentration, x , of Sm 3+ ion shows that these solid solutions obey Vegard's rule as a ( x )=5.4089+0.10743 x for Ce 1− x Sm x O 2−1/2 x . For SDC ceramics sintered at 1500°C for 5 h, the bulk density was over 95% of the theoretical density; the maximum ionic conductivity, σ 800°C =(22.3±1.14) × 10 −3 S/cm with minimum activation energy, E a =0.89±0.02 eV, was found in the Ce 0.80 Sm 0.20 O 1.90 ceramic. A dense Ce 0.8 Sm 0.2 O 1.9 ceramic with a grain size distribution of 0.5–4 μm can be obtained by controlling the soaking time at 1500°C. When the soaking time was increased, the microhardness of Ce 0.8 Sm 0.2 O 1.9 ceramic increased, the toughness slightly decreased, which was related to grain growth with the soaking time.