Development of ScSZ electrolyte fabricated by low pressure plasma spray for metal supported SOFCs applications

For develop metal support SOFCs instead of electrolyte or anode support, low pressure plasma spraying is an attractive method which can significantly avoid the oxidation of metal substrate. In this study, both anode and electrolyte was fabricated by LPPS method. To investigate the microstructure of ScSZ, the spraying distance of electrolyte was set to 150,200,250,300,350 mm. The fragile cross microstructure suggests that the typical lamellar structure is replaced by transgranular structure though in a relatively low temperature(<350℃). The apparent porosity of ScSZ coating is 4.75-6.83% using image analysis method. The ionic conductivity of sprayed coating at 250mm spraying distance can reach 0.068 S﹒cm^-1 at 750℃, ~68% standard of bulk material. The average specific surface area of ScSZ coating top surface can reach 6.53 to 8.30 measured by a 3D confocal laser microscope. Finally, test cell based on low pressure plasma sprayed ScSZ electrolyte membranes shows a maximum output power density of 1111.6 mW﹒cm^-2 and an OCV of 1.07V at 750℃.The ohmic resistance of whole cell is 0.1 Ω · cm² and the total resitance of whole cell is 0.15 Ω · cm², suggesting that low pressure plasma spraying is a promising approach for manufacturing of high-performance MS-SOFCs.