Fabrication of Thin-Film SOFC by Plasma Spray Techniques

摘要

Based on the plasma spray technology a concept for a planar thin-film SOFC to be operated at reduced operating temperatures below 800°C has been developed at DLR Stuttgart. In this spray concept the complete multilayer membrane-electrode assembly (MEA) consisting of thin electrolyte and electrode layers each with a thickness of 30 - 50 μm is fabricated in only one process step. By applying special plasma torches the different layers - structured porous electrodes and a dense YSZ or ScSZ electrolyte - are consecutively deposited onto a porous metallic substrate such as a felt structure or a porous plate. Due to this supporting substrate cell sizes up to a dimension of 20 x 20 cm~2 to be assembled in a stack can be produced. The spray process has the potential to be transferred to a mass production process for a cost-effective SOFC production. In the present paper the principle of the spray concept and the features of the applied plasma spray processes are described. The state of development of plasma sprayed thin-film cells of different sizes by means of structural and electrochemical characterisation is reported.