Sökning: "Protonic conductivity"

Visar resultat 1 - 5 av 6 avhandlingar innehållade orden Protonic conductivity.

  1. 1. Proton conductivity in acceptor-doped lanthanide based pyrochlore oxides

    Detta är en avhandling från Göteborg : Chalmers University of Technology

    Författare :Karinh Eurenius; Göteborgs universitet.; Gothenburg University.; [2009]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Pyrochlore; Rietveld refinement; Proton conductivity; Electrical impedance spectroscopy; Concentration Cell Electromotive Force Method.;

    Sammanfattning : A high interest in developing new materials for SOFC applications in the temperature range of approximately 200–500 C has been growing lately. The lower activation energies for proton (H+) mobility can give higher conductivity in this temperature range. LÄS MER

  2. 2. Functional Oxide Materials exhibiting Ionic Conductivity for Future Energy Conversion Needs

    Detta är en avhandling från Göteborg : Chalmers University of Technology

    Författare :FRANCIS GACHAO KINYANJUI; [2013]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; neutron diffraction; perovskites; oxygen deficient perovskites; BaSnO3; Rietveld refinements; BaZrO3; in-situ cells; proton conduction; deuteron position; Ba3In2ZrO8;

    Sammanfattning : Fuel cells are electrochemical devices that transform the chemical energy in hydrogen and oxygen into electrical energy at high efficiencies and produce only water vapour emissions. Materials with the perovskite or fluorite structure types are commonly employed as the ion conducting ceramic electrolyte membranes in intermediate and high temperature fuel cells. LÄS MER

  3. 3. Exploratory Study of Novel Materials Used for Intermediate Temperature Solid Oxide Fuel Cell (IT-SOFC) Electrolytes

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Junfu Bu; KTH.; [2014]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hafnium oxide; Solid oxide fuel cells SOFCs ; Electrolyte; Electrochemical impedance spectroscopy; Solid state reaction method; Solid state reactive sintering SSRS ; Ionic conductivity; oxygen ion conductivity; Protonic conductivity; Composite electrolyte.;

    Sammanfattning : Currently, yttria-stabilized zirconia (YSZ) is still the dominant electrolyte material in commercial SOFC applications. But it has severe drawbacks due to its high operating temperatures. In present work, two electrolyte materials: Hf0.69Y0. LÄS MER

  4. 4. Proton Conducting Ceramics; Synthesis, Characterization and Sample Cell Environments

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :FRANCIS GACHAO KINYANJUI; [2012]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; perovskites; neutron diffraction; Rietveld refinements; BaSnO3; in-situ cell; deuteron position; proton conduction; BaZrO3;

    Sammanfattning : Acceptor doped Perovskite ceramics have been shown to exhibit high levels of protonic conduction in humid atmospheres. However significant grain boundary resistance and long sintering times required to achieve sufficient grain size growth has hindered their widespread application as electrolyzers, fuel cells and gas separation membranes. LÄS MER

  5. 5. Hydrogen in oxides: a density-functional study of thermodynamic and kinetic aspects

    Detta är en avhandling från Stockholm : KTH Royal Institute of Technology

    Författare :Mårten Björketun; [2007]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; proton conduction; La$_2$Zr$_2$O$_7$; protonation; kinetic Monte Carlo; density functional theory.; BaZrO$_3$; hydrogen oxide systems; electronic structure;

    Sammanfattning : Many solid oxides, especially those possessing a perovskite structure, exhibit significant proton conductivity when being acceptor doped and placed in hydrogen-containing atmospheres. Consequently, they have attracted attention foruse as solid membranes in electrochemical devices such as gas sensors, steam electrolyzers and fuel cells. LÄS MER