Search for dissertations about: "ceramic electrolyte"

Showing result 1 - 5 of 11 swedish dissertations containing the words ceramic electrolyte.

  2. 1. Point defects and ion conduction in solid oxides: a first-principles case study of La2Zr2O7

    Author : Joakim Nyman; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; proton; self compensation; hydrogen economy; DFT; La2Zr2O7; acceptor doping; lanthanum zirconate; oxygen vacancy; SOFC; pyrochlore; point defect; trapping; computational methods; solid oxide; charge compensation; first principles; ion conduction; solid oxide fuel cell; ceramic electrolyte; defect cluster; fuel cell; hydrogen;

    Abstract : In the endeavor to attain a clean environment and sustainable energy consumption, the notion of a future hydrogen economy stands out as one of the grandest visions. Striving for this vision, a critical task lies in optimizing the performance of the fuel-cell devices responsible for extracting electric power from the energy stored in hydrogen molecules. READ MORE

  4. 2. Proton conductivity of lanthanum and barium zirconate: Microscale aspects on first-principles basis

    Author : Joakim Nyman; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; first principles; trapping; conductivity; grain boundary; segregation; pyrochlore; space charge; solid oxide fuel cell; depletion; electrolyte; La2Zr2O7; oxygen vacancy; BaZrO3; proton; DFT; point defect; perovskite; acceptor;

    Abstract : Fuel cells are devices which convert chemical energy into electrical energy cleanly and efficiently. Development of fuel cells compatible with hydrocarbon fuels would make more efficient use of present fossil and renewable fuels, and also enable progress towards a future hydrogen economy. READ MORE

  5. 3. Advanced Functional Materials for Intermediate-Temperature Ceramic Fuel Cells

    Author : Zhan Gao; Bill Bergman; Mogens Mogensen; Ceramics; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : Low to intermediate-temperature solid oxide fuel cell (SOFC, 500 oC-700 oC) based on doped ceria (DCO) electrolyte has attracted much attention during the last decade. However, DCO suffers from electronic conduction caused byreduction of Ce (IV) to Ce (III) at high temperatures and low oxygen partial pressures and has a high grain-boundary resistivity. READ MORE

  6. 4. Development and characterization of functional composite materials for advanced energy conversion technologies

    Author : Liangdong Fan; Bin Zhu; Torsten Fransson; Mahmut D. MAT; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Low temperature ceramic fuel cell; Ceria-carbonate composite; Electrolysis; Transition metal oxide; Symmetrical fuel cells; All-nanocomposite fuel cell; Electrolyte-free fuel cell; Solar cell; ion conductor and semiconductor; SRA - Energy; SRA - Energi;

    Abstract : The solid oxide fuel cell (SOFC) is a potential high efficient electrochemical device for vehicles, auxiliary power units and large-scale stationary power plants combined heat and power application. The main challenges of this technology for market acceptance are associated with cost and lifetime due to the high temperature (700-1000 oC) operation and complex cell structure, i. READ MORE

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

    Author : Junfu Bu; Pär Jönsson; Zhe Zhao; Christopher Knee; KTH; []
    Keywords : 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.;

    Abstract : 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. READ MORE