Stability of double perovskite cathodes under high humidity for solid oxide fuel cells

Solid Oxide Fuel Cells (SOFCs) can directly convert a wide variety of fuels to electricity efficiently. They can also be run in reverse as Solid Oxide Electrolysis Cells (SOECs) to produce hydrogen (and carbon-containing fuels) from electrolysis of water (and carbon dioxide). However, the kinetics of oxygen reduction reaction (ORR) on the cathode is often hindered by various contaminants, which may react with the cathode to form insulating phases and degrade fuel cell performance. The stability and performance of the cathode in moisture is critical to the cell performance as SOFCs and SOECs. Several state-of-the-art cathode materials are investigated in a high moisture environment to uncover their performance and degradation mechanism. First, powders of electrode materials were analyzed for any degradation before and after long-term moisture exposure using XRD to probe the bulk and Raman Spectroscopy to probe the surface. SEM was also used to characterize any morphological changes during the exposure. Second, electrochemical impedance spectroscopy (EIS) was used to monitor the long-term performance of symmetric cells under various conditions. Finally, current-voltage relationships of symmetric cells were acquired under typical operating conditions for SOFCs and SOECs to determine the polarization resistance, stability and durability of the cathode materials.

Level thesis:degree_level

Masters

Department dc:contributor.department

Materials Science and Engineering

Grantor dc:publisher

Georgia Institute of Technology

Year dc:date.issued

2019

Author dc:creator

• Liu, Yuchen

Advisor dc:contributor.advisor

• Liu, Meilin

Committee members dc:contributor.committeemember

• Singh, Preet M.
• Alamgir, Faisal M.

• Solid oxide fuel cells
• Solid oxide electrolysis cells
• Water vapor
• Electrochemical impedance spectroscopy
• Cathode
• Double perovskite

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/1853/62707

OAI identifier oai:identifier

oai:repository.gatech.edu:1853/62707