Niobium-doped strontium titanates as SOFC anodes

Peter Blennow Tullmar, Kent Kammer Hansen, L. Reine Wallenberg, Mogens Bjerg Mogensen

    Research output: Contribution to journalConference articleResearch

    Abstract

    Sr-vacancy compensated Nb-doped SrTiO(3) with the nominal composition Sr(0.94)Ti(0.9)Nb(0.1)O(3) has been evaluated as part of a solid oxide fuel cell (SOFC) anode material in terms of redox stability, electrical conductivity, as well as electrochemical properties. Sr(0.94)Ti(0.9)Nb(0.1)O(3) has been synthesized with a recently developed modified glycine-nitrate process. The synthesized powders have been calcined and sintered in air or in 9% H(2) / N(2) between 800 - 1400 degrees C. After calcination the samples were single phase Nb-doped strontium titanate with grain sizes of less than 100 nm in diameter on average. The phase purity, defect structure, and microstructure of the materials have been analyzed with SEM, XRD, and TGA. The electrical conductivity of the Nb-doped titanate decreased with increasing temperature and showed a phonon scattering conduction mechanism with sigma > 120 S/cm at 1000 degrees C (in 9% H(2) / N(2)). The electrochemical properties of Sr(0.94)Ti(0.9)Nb(0.1)O(3) and a composite electrode of Sr(0.94)Ti(0.9)Nb(0.1)O(3)/YSZ have been investigated by using a symmetrical cell configuration. The tests indicated that the electrodes were redox stable and showed a potential ability of the Nb-doped titanates to be used as a part of a SOFC anode. However, the catalytic activity of the materials was not sufficient and it needs to be improved if titanate based materials are to be realized as constituents in SOFC anodes.
    Original languageEnglish
    JournalCeramic Engineering and Science Proceedings
    Volume28
    Issue number4
    Pages (from-to)203-214
    ISSN0196-6219
    Publication statusPublished - 2008
    Event31st International Conference on Advanced Ceramics and Composites: Advances in Solid Oxide Fuel Cells 3 - Daytona Beach, FL, United States
    Duration: 21 Jan 200726 Jan 2007
    Conference number: 31

    Conference

    Conference31st International Conference on Advanced Ceramics and Composites
    Number31
    CountryUnited States
    CityDaytona Beach, FL
    Period21/01/200726/01/2007

    Bibliographical note

    Change template to: Article in proceedings
    host pub. title: Advances in Solid Oxide Fuels Cells III
    isbn: 978-0-470-19635-9

    Keywords

    • Solid Oxide Fuel Cells
    • Fuel Cells and hydrogen

    Cite this

    Blennow Tullmar, P., Kammer Hansen, K., Wallenberg, L. R., & Mogensen, M. B. (2008). Niobium-doped strontium titanates as SOFC anodes. Ceramic Engineering and Science Proceedings, 28(4), 203-214.