Hydrothermal synthesis and properties of ceria solid electrolytes

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

OSTI ID:20019135

Greenblatt, M; Huang, W; Shuk, P

The structure, thermal expansion coefficients and ionic/electronic conductivity of (Ce{sub 1{minus}x}Sm{sub x}){sub 1{minus}y}(Tb/Pr){sub y}O{sub (2{minus}x/2)+{delta}} (x = 0--0.30; y = 0--0.10) and Ce{sub 1{minus}x}Ca{sub x}O{sub 2{minus}x} (x = 0--0.17) solid electrolytes prepared hydrothermally were investigated. The uniformly small particle size (7--68 nm) of the hydrothermally prepared materials allows sintering of the samples into highly dense ceramic pellets at 1400 C, a significantly lower temperature, compared to that at 1600--1650 C required for samples prepared by solid state techniques. The maximum ionic conductivity in Ce{sub 1{minus}x}(Sm/Ca){sub x}O{sub 2{minus}{delta}} was found at x = 0.17 for the Sm ({sigma}{sub 600 C} = 5.7 x 10{sup {minus}3} S/cm). In (Ce{sub 0.83}Sm{sub 0.17}){sub 1{minus}y}(Tb/Pr){sub y}O{sub 1.815+{delta}} the maximum conductivity was found at y = 0.10 for the Pr and Tb substituted ceria ({sigma}{sub 600 C} = 7.6 x 10{sup {minus}3} S/cm, E{sub a} = 0.55 eV and {sigma}{sub 600 C} = 10{sup {minus}2} S/cm, E{sub a} = 0.72 eV respectively) with electronic contribution to total conductivity around 20--30%. When the Tb or Pr substitution in Ce{sub 0.83}Sm{sub 0.17}O{sub 1.915} is reduced, the conductivity becomes more ionic, and is purely ionic at 2%. However the conductivity at this lower level doping is not significantly lower.

• Research Organization: Rutgers, The State Univ. of New Jersey, Piscataway, NJ (US)
• OSTI ID: 20019135
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
CALCIUM OXIDES
CERIUM OXIDES
CRYSTAL STRUCTURE
DOPED MATERIALS
EXPERIMENTAL DATA
IONIC CONDUCTIVITY
PRASEODYMIUM OXIDES
SAMARIUM OXIDES
SOLID ELECTROLYTE FUEL CELLS
SOLID ELECTROLYTES
TERBIUM OXIDES
THERMAL EXPANSION