Development of ScSZ Electrolyte by Very Low Pressure Plasma Spraying for High-Performance Metal-Supported SOFCs

Very low pressure plasma spraying (VLPPS) is an attractive method for metal-supported solid oxide fuel cells, wherein it can significantly avoid the oxidation of metal substrate. In this study, scandia-stabilized zirconia electrolyte was fabricated by VLPPS. To investigate the microstructure of coatings, the spraying distances were set to 150, 250 and 350 mm. The fractured morphology suggests that, at a relatively low deposition temperature (< 350 degrees C), typical lamellar structure was replaced by trans-granular structure. The apparent porosity of coatings ranges from 4.75 to 6.83%, as per the image analysis method. The ionic conductivity of coating at 250 mm was 0.068 S cm(-1), which was similar to 68% of bulk. The ratio of surface area to projected area of coatings surface could reach 6.53-8.30 measured by a 3D confocal laser microscope. Finally, testing cells showed a maximum output power density of 1112 mW cm(-2) and an OCV of 1.07 V at 750 degrees C. The ohmic resistance of whole cell was 0.1 omega cm(2), and the total resistance was 0.15 omega cm(2). The results suggest that very low pressure plasma spraying is a promising approach for the manufacturing of high-performance MS-SOFCs.