Doctoral Dissertations

Abstract

"Solid oxide fuel cells (SOFCs) are electrochemical devices which can convert chemical energy to electrical energy with efficiencies up to 60%. In order for SOFCs to be favorable energy conversion devices, the power obtained from a unit volume should be improved. This corresponds to minimized resistances from SOFC components (composite electrodes and electrolyte). Stability of the generated power is another important issue. Degradation of SOFCs with time due to microstructural processes or chemical reactions that occur at operating conditions; and due to reduction/oxidation cycles caused by the changes in the anode has been an important obstacle that has prevented the widespread commercial use of SOFCs. In this dissertation, the electrochemical properties of SOFC electrodes prepared by an infiltration technique were investigated. The long-term behavior and redox stability of the electrodes were evaluated individually and in the form of complete SOFCs. Interpretation of impedance spectra was used extensively to gain some fundamental understanding of the electrochemical properties of the electrodes along with voltammetry. Microstructural characterization was performed by electron microscopy techniques. LSM-YSZ cathodes prepared by polymeric LSM precursor infiltration resulted in cathode polarization resistance of 0.022 Ohm.cm² at 800 °C, which then increased to 0.035 Ohm.cm² and remained stable at this value for 100 hours. SOFCs with Ni-YSZ anodes and LSM-YSZ cathodes prepared by infiltration yielded total electrode polarizations of 0.080 Ohm.cm² at 800 °C. The electrode polarization resistances showed no degradation with time or upon redox cycling"--Abstract, page iv.

Advisor(s)

Dogan, Fatih

Committee Member(s)

Huebner, Wayne
Hilmas, Greg
OKeefe, Matt
Xing, Yangchuan

Department(s)

Materials Science and Engineering

Degree Name

Ph. D. in Materials Science and Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2013

Journal article titles appearing in thesis/dissertation

  • Efficient Cathodes for Solid Oxide Fuel Cells Prepared by Polymeric Precursor Infiltration
  • Redox Stable Solid Oxide Fuel Cells with Ni-YSZ Cermet Anodes Prepared by Polymeric Precursor Infiltration
  • Optimization of Redox Stable Ni-YSZ Anodes for SOFCs by Two-Step Infiltration
  • Stability and Performance of Solid Oxide Fuel Cells with Nanocomposite Electrodes
  • Solid Oxide Fuel Cells with Symmetrical Pt-YSZ Electrodes Prepared by YSZ Infiltration
  • Microstructure and Electrical Properties of Infiltrated Ni-YSZ Cermets
  • Redox Cycling of Electrolyte Supported SOFCs with Co-sintered Ni-YSZ Anodes

Pagination

xii, 139 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2013 Aligul Buyukaksoy, All rights reserved.

Document Type

Dissertation - Open Access

File Type

text

Language

English

Library of Congress Subject Headings

Solid oxide fuel cells -- Computer simulation
Solid oxide fuel cells -- Reliability
Solid oxide fuel cells -- Stability
Doped semiconductors -- Computer simulation
Voltammetry -- Computer simulation
Fuel cells -- Electrodes -- Computer simulation
Oxidation-reduction reaction
Polymeric composites

Thesis Number

T 10311

Electronic OCLC #

853501608

Share

 
COinS