Search for dissertations about: "Oxygen ion conductivity"

Showing result 1 - 5 of 21 swedish dissertations containing the words Oxygen ion conductivity.

2. 1. Cation Conduction and Coordination in Carbonyl-Containing Compounds : Li+ Transport in Alternative Polymer Electrolyte Host Materials

   Author : Therese Eriksson; Daniel Brandell; Jonas Mindemark; Claudio Gerbaldi; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Solid polymer electrolytes; Lithium ion batteries; Ion transport; Polyester; Polycarbonate; Polyketone; Ion coordination; Kemi med inriktning mot materialkemi; Chemistry with specialization in Materials Chemistry;

   Abstract : The field of solid polymer electrolytes (SPEs) used to create safer lithium-ion batteries has been dominated by polyethylene oxide (PEO) since the discovery of its ion-conducting properties in the 1970s. In this thesis, as an alternative, the ion coordination and conduction properties of SPEs based on polyketones, polyesters and polycarbonates are investigated. READ MORE

4. 2. 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

5. 3. Ionic transport of α-alumina below 1000°C : an in-situ impedance spectrosocpy study

   Author : Johan Öijerholm; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; α-alumina; in-situ impedance spectroscopy; molecular dynamics; spark plasma sintering; conductivity; microstructure; Materialvetenskap; Materials science; Teknisk materialvetenskap;

   Abstract : Ionic conductivity of metal oxides is critical for the function of a broad range of different components, such as electrolytes in solid oxide fuel cells and alloys designed for high temperature applications. In both cases the ionic conductivity can be studied by in situ impedance spectroscopy, which is also able to reveal information on the dielectric properties of the metal oxides, and in some cases the influence of their microstructure. READ MORE

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

   Author : FRANCIS GACHAO KINYANJUI; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE

7. 5. Acceptor-Doped BaZrO3 Perovskite: Synthesis, Structure and Proton Conductivity

   Author : Istaq Ahmed; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Impedance spectroscopy; Perovskite; Neutron diffraction; Rietveld refinement; BaZrO3.; Proton conductor;

   Abstract : Acceptor-doped perovskite oxides exhibit significant proton conductivity in hydrogen containing atmospheres. Therefore, they have potential for use as separator materials for various electrochemical devices including gas sensors, electrolysers and fuel cells. READ MORE