TEM Study on SOFC Interconnects
EMSL Project ID
10901
Abstract
In recent years, progress in materials and fabrication techniques have allowed for a reduction in solid oxide fuel cell (SOFC) operating temperatures to a range (e.g., 650-800ºC) where oxidation resistance high temperature alloys such as chromia-forming ferritic stainless steels can be considered as replacement materials for the traditional ceramic interconnect materials used in high temperature (900-1000ºC) SOFC stacks. However, even at these reduced temperatures, the SOFC interconnect application remains challenging for these high temperature-oxidation resistant alloys. The chromia scales on the steels can grow to microns or even tens of microns after thousands of hours in the SOFC environment, leading to high electrical resistance which causes unacceptably high degradation rates in stack performance. The chromia forming alloys present another challenge in the evaporation of chromium species from the scale and subsequent deposition of chromium oxides at the cathode/electrolyte interface which, by increasing diffusion and charge transfer resistances at the interface, degrade cell performance. To develop solutions to these challenges and improve performance of the alloy interconnects, there is a need of understanding the degradations occurring on the interconnect surface and their interfaces. For this purpose, TEM is proposed as a requisite tool to interpret structure, microstructure and local chemistry of scales and interfaces.
Project Details
Project type
Exploratory Research
Start Date
2004-08-26
End Date
2007-07-06
Status
Closed
Released Data Link
Team
Principal Investigator