| Abstract: |
Samaria-doped ceria (SDC) has become a promising material for the fabrication of high-performance, intermediate-temperature solid oxide fuel cells (SOFCs). While typical SOFC materials, such as yttria-stabilized zirconia (YSZ), require high temperatures ( > 800°C) to exhibit suitable ionic conductivity for cell performance, SDC displays similar ionic conductivities at lower temperatures (600°C 650°C). This decrease in operating temperature results in substantially more flexibility in material choices for the overall fuel cell system. For example, robust and inexpensive stainless steel materials can be used for interconnect and cell support systems at this temperature. A manufacturing technique that facilitates the use of metal supports for SOFCs is atmospheric plasma spraying (APS). In addition to reducing cell costs through the use of metallic support materials, the APS technique has the potential to reduce SOFC fabrication costs through mass production because of the rapid and easy-to-automate nature of the process. Currently, little work has been reported on both the fabrication of SDC coatings using conventional APS processes and the in-flight behaviour of SDC in the plasma during coating application. Therefore, the purpose of this study is to examine the characteristics of SDC coatings fabricated using various APS parameters and to relate these coating properties to the in-flight particle characteristics. The overall objective is to determine suitable APS parameters for the fabrication of high-performance SOFC layers containing SDC.
In this study, the in-flight characteristics, such as particle velocity and surface temperature, of spray-dried SDC agglomerates were analyzed at various plasma spray conditions using the DPV-2000 in-flight particle sensor manufactured by Tecnar Automation. Coatings of SDC were applied on stainless steel substrates using a range of spray conditions, and their resulting microstructures and deposition efficiencies were analyzed. The implication of these results on the potential for SOFC fabrication is discussed.
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