Water vapor effects on the sintering of solid oxide electrolytes
Poster Number
35
Format
Poster Presentation
Faculty Mentor Name
Tien Roehling
Faculty Mentor Department
Engineering and Computer Science
Abstract/Artist Statement
Water vapor effects on the sintering of solid oxide electrolytes Presenter: S. Stefan Soezeri Advisor: Tien Tran Roehling Department of Mechanical Engineering In solid oxide fuel cells (SOFCs), the electrolyte is often a dense, fluorite-structured metal oxide, such as zirconium oxide or cerium oxide. In comparison to these conventional materials, which require operating temperatures in the range of 800-1000 °C, bismuth oxide has demonstrated enhanced oxygen conductivity at intermediate temperatures (500-700 °C). To manufacture these metal oxide electrolytes, the ceramic powders are compressed and then bonded by a solid state technique, called sintering. Densification during sintering mainly occurs by surface and volume diffusion, and to a lesser extent, by evaporation-condensation. In this study, the effect of water vapor on bismuth oxide sintering is investigated. An experimental apparatus was designed in order to allow sintering in a tube furnace to occur in air, or under flowing water vapor at 1 atm. The preliminary results demonstrate a clear enhancement in densification in the presence of water vapor. The increase in densification rates observed may be due to the formation of high vapor pressure metal oxyhydroxides, which can increase the contribution of evaporation condensation to densification. Although a facile and inexpensive solution, sintering in water vapor-containing atmospheres can effectively improve the efficiency SOFC electrolyte fabrication.
Location
DeRosa University Center, Ballroom
Start Date
25-4-2015 10:00 AM
End Date
25-4-2015 12:00 PM
Water vapor effects on the sintering of solid oxide electrolytes
DeRosa University Center, Ballroom
Water vapor effects on the sintering of solid oxide electrolytes Presenter: S. Stefan Soezeri Advisor: Tien Tran Roehling Department of Mechanical Engineering In solid oxide fuel cells (SOFCs), the electrolyte is often a dense, fluorite-structured metal oxide, such as zirconium oxide or cerium oxide. In comparison to these conventional materials, which require operating temperatures in the range of 800-1000 °C, bismuth oxide has demonstrated enhanced oxygen conductivity at intermediate temperatures (500-700 °C). To manufacture these metal oxide electrolytes, the ceramic powders are compressed and then bonded by a solid state technique, called sintering. Densification during sintering mainly occurs by surface and volume diffusion, and to a lesser extent, by evaporation-condensation. In this study, the effect of water vapor on bismuth oxide sintering is investigated. An experimental apparatus was designed in order to allow sintering in a tube furnace to occur in air, or under flowing water vapor at 1 atm. The preliminary results demonstrate a clear enhancement in densification in the presence of water vapor. The increase in densification rates observed may be due to the formation of high vapor pressure metal oxyhydroxides, which can increase the contribution of evaporation condensation to densification. Although a facile and inexpensive solution, sintering in water vapor-containing atmospheres can effectively improve the efficiency SOFC electrolyte fabrication.