Process Development for Nanostructured Functional Layers by Liquid Injection Plasma Spraying for Solid Oxide Fuel Cells

Development and progress to produce nanostructured solid oxide fuel cells by liquid injection plasma spraying is presented. Two different ways to create nanostructured functional layers by plasma spray are discussed. Firstly in suspension plasma spraying (SPS) nanopowders are injected into the plasma in a solvent. The second method presented is solution precursor plasma spraying (SPPS) that injects liquid precursors into the plasma flame. Metallographic cross sections and SEM images of fractured coatings show the differences in microstructure of these coating techniques. SPPS has its advantages in high stoichiometric flexibility and high porosity. SPS produces dense layers most appropriate for thin electrolytes and also highly porous coatings with a high specific surface area. The deposition efficiency (DE) of different injection techniques shows that impulse of injected droplets has a great influence. Both techniques have tremendous potential for high performance SOFCs.