High total proton conductivity in large-grained yttrium-doped barium zirconate

Yoshihiro Yamazaki, Raul Hernandez-Sanchez, Sossina M. Haile

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266 Citations (Scopus)

Abstract

Barium zirconate has attracted particular attention among candidate proton conducting electrolyte materials for fuel cells and other electrochemical applications because of its chemical stability, mechanical robustness, and high bulk proton conductivity. Development of electrochemical devices based on this material, however, has been hampered by the high resistance of grain boundaries, and, due to limited grain growth during sintering, the high number density of such boundaries. Here, we demonstrate a fabrication protocol based on the sol - gel synthesis of nanocrystalline precursor materials and reactive sintering that results in large-grained, polycrystalline BaZr 0.8Y 0.2C 3-δ of total high conductivity, ∼ 1 × 10 -2 Scm -1 at 450 °C. The detrimental role of grain boundaries in these materials is confirmed via a comparison of the conductivities of polycrystalline samples with different grain sizes. Specifically, two samples with grain sizes differing by a factor of 2.3 display essentially identical grain interior conductivities, whereas the total grain boundary conductivities differ by a factor of 2.5-3.2, depending on the temperature (with the larger-grained material displaying higher conductivity).

Original languageEnglish
Pages (from-to)2755-2762
Number of pages8
JournalChemistry of Materials
Volume21
Issue number13
DOIs
Publication statusPublished - Jul 14 2009
Externally publishedYes

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All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Chemical Engineering(all)
  • Materials Chemistry

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