Synthesis and characteristics of La{sub 1{minus}x}Sr{sub x}MnO{sub 3} ceramics for cathode materials of SOFC

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:242503

Zhong-Tai, Z; Lin, O; Zi-Long, T ^[1]

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1. Tsinghua Univ., Beijing (China). Dept. of Materials Science and Engineering

The fine powders of cathode materials with composition La{sub 1{minus}x}Sr{sub x}MnO{sub 3} (x = 0--0.6) for solid oxide fuel cells (SOFC) were prepared by the buffer solution method. TG-DTA was applied to study the formation of perovskite oxide and the sintering behavior of strontium-doped lanthanum manganite powders. The crystal structure and morphology of La{sub 1{minus}x}Sr{sub x}MnO{sub 3} were observed by XRD, SEM and TEM. The high-temperature electrical conductivity was measured by the four-probe method. It was indicated that the formation temperature of perovskite-type La{sub 1{minus}x}Sr{sub x}MnO{sub 3} decreased with the increase of Sr content. The La{sub 1{minus}x}Sr{sub x}MnO{sub 3} display three lattice types at room temperature: orthorhombic (0{<=}x{<=}0.15), hexagonal (0.15 {<=} x {<=} 0.45) and cubic (x{>=}0.45). As x increased, the primary cell volume of La{sub 1{minus}x}Sr{sub x}MnO{sub 3} decreased, and an abrupt decline was found around the phase-transformation point. Results showed that the electrical conductivity of La{sub 1{minus}x}Sr{sub x}MnO{sub 3} was influenced remarkably by the content of Sr, the peak value of 200s/cm was located at x = 0.5 (at 1,273 K in air).

• OSTI ID: 242503
• Report Number(s): CONF-950683--; ISBN 1-56677-095-5
• Country of Publication: United States
• Language: English

Related Subjects

30 DIRECT ENERGY CONVERSION
36 MATERIALS SCIENCE
ACTIVATION ENERGY
CATHODES
CRYSTAL STRUCTURE
DIFFERENTIAL THERMAL ANALYSIS
ELECTRIC CONDUCTIVITY
LANTHANUM OXIDES
MANGANESE OXIDES
SCANNING ELECTRON MICROSCOPY
SOLID ELECTROLYTE FUEL CELLS
STRONTIUM OXIDES
SYNTHESIS
THERMAL GRAVIMETRIC ANALYSIS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION