A composite electrolyte for an SOFC consisting of a ceria sheet and a zirconia film deposited by sol-gel method

Conference · Wed Jul 01 04:00:00 EDT 1998

OSTI ID:20019141

Chiba, Reiichi; Yoshimura, Fumikatsu; Yamaki, Junichi

The authors investigated a composite electrolyte for solid oxide fuel cells prepared by coating a ceria sheet (Ce{sub 0.8}Gd{sub 0.2}O{sub 2{minus}d} or GDC) with a scandia alumina doped zirconia (0.850ZrO{sub 2}-0.110Sc{sub 2}O{sub 3}-0.04Al{sub 2}O{sub 3}) film by the sol-gel method. The sol-gel film annealed at 1,200 C was examined by X-ray diffraction analysis and found to be in a cubic phase at room temperature. The ionic conductivity of this film is comparable to that of bulk sintered at 1,620 C. Scanning electron microscope observations revealed that the film forms a good interface with the electrolyte of the ceria sheet, even though the annealing temperature is as low as 1,200 C. They fabricated a single cell consisting of a composite electrolyte, a La{sub 0.8}Sr{sub 0.2}MnO{sub 3} cathode and a Ni-YSZ anode. The composite electrolyte consisted of zirconia film about one micron thick deposited by the sol-gel method and a 0.2 mm thick ceria sheet. A cell operated with moist H{sub 2} and O{sub 2} gas exhibited an open circuit voltage of 1.00 V at 800 C. This value is much closer to the value of 1.13 V expected from the Nernst equation than the value of 0.76 V for a cell with a ceria sheet but without the sol-gel film.

• Research Organization: NTT Integrated Information and Energy System Labs., Tokai, Ibaraki (JP)
• OSTI ID: 20019141
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ANODES
CATHODES
CERIUM OXIDES
COMPOSITE MATERIALS
CRYSTAL STRUCTURE
DOPED MATERIALS
EXPERIMENTAL DATA
FABRICATION
GADOLINIUM OXIDES
IONIC CONDUCTIVITY
SOLID ELECTROLYTE FUEL CELLS
SOLID ELECTROLYTES
ZIRCONIUM OXIDES