Layered YSZ/SCSZ/YSZ Electrolytes for Intermediate Temperature SOFC Part I: Design and Manufacturing

Journal Article · Sun Jan 01 00:00:00 EST 2012 · Fuel Cells

OSTI ID:1050952

Orlovskaya, Nina ^[1]; Klimov, Mikhail ^[2]; Huang, Xinyu ^[3]; Cullen, David A ^[1]; Graule, Thomas ^[4]; Kuebler, Jakob ^[4]

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1. ORNL
2. University of Central Florida
3. University of South Carolina
4. EMPA, Laboratory for High Performance Ceramics, Duebendorf, Switzerland

(Sc2O3)0.1(CeO2)0.01(ZrO2)0.89 (SCSZ) ceramic electrolyte has superior ionic conductivity in the intermediate temperature range (700 800 C), but it does not exhibit good phase and chemical stability in comparison with 8 mol% Y2O3 ZrO2 (YSZ). To maintain high ionic conductivity and improve the stability in the whole electrolyte, layered structures with YSZ outer layers and SCSZ inner layers were designed. Because of a mismatch of coefficients of thermal expansion and Young's moduli of SCSZ and YSZ phases, upon cooling of the electrolytes after sintering, thermal residual stresses will arise, leading to a possible strengthening of the layered composite and, therefore, an increase in the reliability of the electrolyte. Laminated electrolytes with three, four, and six layers design were manufactured using tape-casting, lamination, and sintering techniques. After sintering, while the thickness of YSZ outer layers remained constant at 30 m, the thickness of the SCSZ inner layer varied from 30 m for a Y SC Y three-layered electrolyte, 60 m for a Y 2SC Y four-layered electrolyte, and 120 m for a Y 4SC Y six-layered electrolyte. The microstructure, crystal structure, impurities present, and the density of the sintered electrolytes were characterized by scanning and transmission electron microscopy, X-ray and neutron diffraction, secondary ion mass spectroscopy, and water immersion techniques.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Shared Research Equipment Collaborative Research Center
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 1050952
• Journal Information: Fuel Cells, Vol. 12, Issue 5; ISSN 1615-6846
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
CERAMICS
CRYSTAL STRUCTURE
DESIGN
ELECTROLYTES
IMPURITIES
IONIC CONDUCTIVITY
MANUFACTURING
MASS SPECTROSCOPY
MICROSTRUCTURE
NEUTRON DIFFRACTION
RELIABILITY
RESIDUAL STRESSES
SINTERING
SOLID OXIDE FUEL CELLS
STABILITY
THERMAL EXPANSION
THICKNESS
TRANSMISSION ELECTRON MICROSCOPY
WATER