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Title: Substitution induced B-cation ordering in solid oxide fuel cell ceramics : (La{sub 0.8}Sr{sub 0.2})(M{sub 0.9}Ni{sub 0.1})O{sub 3} (M = Mn, Cr).

Abstract

No abstract prepared.

Authors:
; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
EE
OSTI Identifier:
927503
Report Number(s):
ANL/CMT/JA-58498
Journal ID: ISSN 0025-5408; MRBUAC; TRN: US200811%%241
DOE Contract Number:
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Mater. Res. Bull.; Journal Volume: 42; Journal Issue: 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
30 DIRECT ENERGY CONVERSION; CERAMICS; SOLID OXIDE FUEL CELLS; ANL

Citation Formats

Vaughey, J. T., Mawdsley, J. R., Krause, T. R., and Chemical Engineering. Substitution induced B-cation ordering in solid oxide fuel cell ceramics : (La{sub 0.8}Sr{sub 0.2})(M{sub 0.9}Ni{sub 0.1})O{sub 3} (M = Mn, Cr).. United States: N. p., 2007. Web. doi:10.1016/j.materresbull.2007.08.025.
Vaughey, J. T., Mawdsley, J. R., Krause, T. R., & Chemical Engineering. Substitution induced B-cation ordering in solid oxide fuel cell ceramics : (La{sub 0.8}Sr{sub 0.2})(M{sub 0.9}Ni{sub 0.1})O{sub 3} (M = Mn, Cr).. United States. doi:10.1016/j.materresbull.2007.08.025.
Vaughey, J. T., Mawdsley, J. R., Krause, T. R., and Chemical Engineering. Mon . "Substitution induced B-cation ordering in solid oxide fuel cell ceramics : (La{sub 0.8}Sr{sub 0.2})(M{sub 0.9}Ni{sub 0.1})O{sub 3} (M = Mn, Cr).". United States. doi:10.1016/j.materresbull.2007.08.025.
@article{osti_927503,
title = {Substitution induced B-cation ordering in solid oxide fuel cell ceramics : (La{sub 0.8}Sr{sub 0.2})(M{sub 0.9}Ni{sub 0.1})O{sub 3} (M = Mn, Cr).},
author = {Vaughey, J. T. and Mawdsley, J. R. and Krause, T. R. and Chemical Engineering},
abstractNote = {No abstract prepared.},
doi = {10.1016/j.materresbull.2007.08.025},
journal = {Mater. Res. Bull.},
number = 2007,
volume = 42,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}
  • Perovskites are important materials in a number of important technological applications, including solid oxide fuel cells, catalysis, and giant magneto-resistance materials. For many of these purposes, a mixture of B-cations can be used to tune the desired properties, e.g., oxygen reduction, ionic conductivity. For a solid oxide fuel cell, two particular ceramic components are of critical importance and have been extensively studied, the cathode (La{sub 0.8}Sr{sub 0.2})MnO{sub 3-x} and the interconnect material (La{sub 0.8}Sr{sub 0.2})CrO{sub 3}. In this study, we examined the mixed B-cation perovskites (La{sub 0.8}Sr{sub 0.2})(M{sub 0.9}Ni{sub 0.1})O{sub 3} (M = Mn, Cr). All materials were synthesized usingmore » the glycine-nitrate method, followed by air annealing. The structures were determined using powder neutron diffraction methods. Refinement of the data showed that even at this low concentration, the compounds have monoclinic symmetry (P2{sub 1}/n) and that the nickel had a strong preference for the smaller of the two octahedral sites. This small amount of nickel substituted on the B-site resulted in a symmetry reduction when compared to the unsubstituted (LaSr)MnO{sub 3} or (LaSr)CrO{sub 3} materials. Although this structural type has been seen previously in heavily substituted perovskites, these materials show that even at this low level of substitution a segregation of the metals in a manner similar to the double perovskites A{sub 2}BB'O{sub 6-x} can be detected. This may have implications involving material stresses on cycling that may result as the temperature is raised or lowered through this crystallographic transition.« less
  • Solid oxide fuel cells (SOFCs) with thin (La0.9Sr0.1)0.98Ga0.8Mg0.2O3-δ (LSGM) electrolytes are primary candidates for achieving high (> 1 W cm-2) power density at intermediate (< 650 °C) temperatures. Although high power density LSGM-electrolyte SOFCs have been reported, it is still necessary to develop a fabrication process suitable for large-scale manufacturing and to minimize the amount of LSGM used. Here we show that SOFCs made with a novel processing method and a Sr0.8La0.2TiO3-α (SLT) oxide support can achieve high power density at intermediate temperature. The SLT support is advantageous, especially compared to LSGM supports, because of its low materials cost, electronicmore » conductivity, and good mechanical strength. The novel process is to first co-fire the ceramic layers – porous SLT support, porous LSGM layer, and dense LSGM layer – followed by infiltration of nano-scale Ni into the porous layers. Low polarization resistance of 0.188 Ωcm2 was achieved at 650 °C for a cell with an optimized anode functional layer (AFL) and an (La,Sr)(Fe,Co)O3 cathode. Maximum power density reached 1.12 W cm-2 at 650 °C, limited primarily by cathode polarization and ohmic resistances, so there is considerable potential to further improve the power density.« less
  • Polycrystalline samples of La{sub 0.8}Ca{sub 0.2}Fe{sub 0.8}Ni{sub 0.2}O{sub 3-{delta}} (LCFN) with perovskite type structure have been prepared by combustion, freeze drying, citrate-gel process and liquid mix method. The analysis of X-ray powder diffraction indicated that the samples were single phase and crystallized in an orthorhombic (space group, Pnma no. 62) structure. Transmission electron microscopy (TEM) analysis on the synthesized powder at 600 {sup o}C by liquid mix method showed clusters of 150 nm formed by nanoparticles of 20 nm. Electrochemical performance of LCFN cathodes, which are used for intermediate temperature solid oxide fuel cells, were investigated. The polarization resistance wasmore » studied using two different electrolytes: Y-doped zirconia (YSZ) and Sm-doped ceria (SDC). The dc four-probe measurement exhibits a total electrical conductivity, over 100 S cm{sup -1} at T {>=} 600 {sup o}C, pointing out that strontium can be substituted for the cheaper calcium cation without destroying the electrochemical properties. Experimental results indicate that nanoparticles have more advantages in terms of smaller particle size and better electrochemical performance.« less
  • The structure of the (La{sub 0.9}Sr{sub 0.1})(Fe{sub 0.8}Mg{sub 0.2})O{sub 3-y} oxide is investigated using neutron diffraction at temperatures of 10, 295, 500, 700, and 1000 K. The results of the structure refinement are in good agreement with the experimental data on the electrical conductivity and confirm the inference that the oxidation state of iron cations is higher than 3+ and that the structure of the compound is antiferromagnetically ordered at temperatures below 500 K.
  • A binder system containing polyurethane precursors was used to in situ foam (direct foam) a (La{sub 0.6}Sr{sub 0.4}){sub 0.98} (Co{sub 0.2} Fe{sub 0.8}) O{sub 3-{ delta}} (LSCF) composition for solid oxide fuel cell (SOFC) cathode applications. The relation between in situ foaming parameters on the final microstructure and electrochemical properties was characterized by microscopy and electrochemical impedance spectroscopy (EIS), respectively. The optimal porous cathode architecture was formed with a 70 vol% solids loading within a polymer precursor composition with a volume ratio of 8:4:1 (isocyanate: PEG: surfactant) in a terpineol-based ink vehicle. The resultant microstructure displayed a broad pore sizemore » distribution with highly elongated pore structure.« less