PEROVSKITE BASED PROTECTIVE COATINGS FOR SOLID OXIDE FUEL CELL METALLIC INTERCONNECTS

Recent improvements in solid oxide fuel cell (SOFC) performance through the use of anode supported (thin electrolyte) cells have allowed the typical operating temperature to be lowered to 800°C or less. At this operating temperature, lower cost Ni or Fe based metallic interconnects become a potential replacement for the brittle and expensive chromite based ceramic interconnects that were used at higher cell operating temperatures. However, the use of metallic interconnects is not without problems, as the alloys contain Cr at levels that lead to the formation of Cr2O3, which has higher electronic conductivity but can also contribute to cell degradation. Coating chromium containing alloys with LaCrO3 based perovskites is explored as a means to decrease contamination effects of Cr vapor species. This study employs magnetron sputtering to deposit LaCrO3 and Ca doped LaCrO3 thin films, which were then subjected to various annealing conditions, including air and a reducing environment, to assess the influence on film properties. Techniques such as scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, and atomic force microscopy were utilized for characterization, alongside area specific resistance measurements after annealing and extended exposure at elevated temperatures.