Design and Characterization of Nanocomposites Based on Complex Perovskites and Doped Ceria as Advanced Materials for Solid Oxide Fuel Cell Cathodes and Membranes

Abstract

La 0.8 Sr 0.2 Fe 0.6 Ni 0.4 O 3-x -Ce 0.9 Gd 0.1 O 2-x and La 0.8 Sr 0.2 Fe 0.8 Co 0.2 O 3-x -Ce 0.9 Gd 0.1 O 2-x nanocomposites were synthesized via ultrasonic dispersion of nanocrystalline powders of perovskite and fluorite oxides in acetone with addition of a surfactant, followed by drying and sintering at temperatures up to 1200 o C. The evolution of the structure of samples with sintering temperature was studied by XRD and TEM with EDX and compared with the data on conductivity, oxygen isotope exchange, O 2 TPD, H 2 and CH 4 TPR. Preliminary testing of buttonsize cells with cathodes supported on thin YSZ layer covering Ni/YSZ cermet demonstrated a high and stable performance of LSNF -GDC composite promising for the practical application.

Advanced Sintering Techniques in Design of Planar IT SOFC and Supported Oxygen Separation Membranes

“…The increase of oxygen mobility with the amount of GDC phase, and, hence, the length of perovskite-fluorite interface, agrees with suggestion that such an interface provides a path for fast oxygen diffusion due to its specific structure and composition . The values of X v for LFN-GDC composites with a high GDC content are close to those for Sr-containing LSFC-GDC composites known for their very high oxygen mobility (Sadykov et al, 2008). Hence, even composites without Sr and Co in complex perovskites could provide a high bulk oxygen mobility combined with a low reactivity with respect to interaction with YSZ if their composition and sintering procedures are properly optimized.…”

“…Hence, design of thin film SOFC requires also elaboration of nanostructured electrodes compatible with electrolytes from chemical and thermophysical points of view and providing a developed three-phase boundary (TPB). In this respect, broad options are provided by design of nanocomposite mixed ionic-electronic conducting (MIEC) functional layers - Sadykov et al, 2008).…”

Design and characterization of LSM/ScCeSZ nanocomposite as mixed ionic–electronic conducting material for functionally graded cathodes of solid oxide fuel cells

“…La 0.8 Sr 0.2 MnO 3 + x (LSM) and La 0.8 Sr 0.2 Fe 0.6 Ni 0.4 O 3 (LSNF) perovskites were synthesized by Pechini route as described earlier [14,15]. was a commercial product of DKKK (Japan).…”

“…Since performance of composite cathodes strongly depends upon their microstructure, which controls triple-phase boundary (TPB) characteristics [11,13], importance of development of new methods of composite preparation which could allow the tailor-made design of their microstructure is apparent. This paper presents results of research aimed at synthesis of LSMScCeSZ nanocomposite via the ultrasonic treatment of the mixture of perovskite and electrolyte nanopowders in solvents with addition of surfactants, which was earlier successfully applied for perovskitedoped ceria nanocomposite preparation [14][15][16]. The structural, textural, surface and transport characteristics of this nanocomposite were studied by combination of modern methods following earlier described approaches [14][15][16].…”

“…This paper presents results of research aimed at synthesis of LSMScCeSZ nanocomposite via the ultrasonic treatment of the mixture of perovskite and electrolyte nanopowders in solvents with addition of surfactants, which was earlier successfully applied for perovskitedoped ceria nanocomposite preparation [14][15][16]. The structural, textural, surface and transport characteristics of this nanocomposite were studied by combination of modern methods following earlier described approaches [14][15][16]. A special attention was paid to elucidation of the specificity of chemical interaction between perovskite and fluorite phases as well as the effect of perovskite-fluorite interfaces on the oxygen mobility and reactivity.…”