METALLIC SUBSTRATE SUPPORTED THIN-FILM SOFC FOR REDUCED OPERATING TEMPERATURE

摘要

In order to reduce production costs and improve long-term stability second-generation planar solid oxide fuel cells to be operated at reduced operating temperature below 800 ℃ are currently under development world-wide. Lower operating temperature allows for cheaper materials for interconnects and peripheral high-temperature components and promises reduced degradation and thus a longer lifetime of SOFC stacks. Operation at an intermediate temperature regime of 650 - 800℃ requires progress in reducing specific cell resistance. A general approach in this respect is the move from a self-supporting electrolyte to a supported cell technology with thin-film concepts, mostly on the basis of anode-supported cell structures. DLR Stuttgart has developed its own planar thin-film concept of a metallic substrate supported SOFC, the so-called "spray concept", which is based on plasma spray technology for the manufacture of the entire cell. Main advantages of the metallic substrate support are the high mechanical strength and the ability of rapid thermal cycling. The latter is a very important aspect for the development of a SOFC technology for application in the automotive industry as on-board Auxiliary Power Unit (APU). This paper describes the current status of the development of the DLR spray concept aiming at high-performance SOFC stacks for stationary and mobile application including scale-up aspects of the fabrication technology, the stack technology, recent developments with materials and components as well as the electrochemical performance.