Wolfgang Schafbauer

Tape Casting as a Multi Purpose Shaping Technology for Different Applications in Energy Issues

Tape casting is widely used in industrial scale for production of multilayer ceramic capacitors or substrates for different applications. In 2009, it was successfully introduced as standard shaping technology for 3 (BSCF) are shown. The entire scope from the preparation of the used powders, the different manufacturing steps and their optimization potential up to the final tape-cast product will be discussed. The influence of the use of pore forming agents, heat treatment or other parameters during processing will be described in detail. Finally, the option of sequential tape casting of different materials for graded structures as a future step in shaping technology will be presented for different applications.

Development of High Power Density Solid Oxide Fuel Cells (SOFCs) for Long-Term Operation

Solid oxide fuel cells (SOFCs) enable environmentally friendly energy to be produced with high efficiency. The market entry of SOFC systems depends on the functionality of the components and on the costs. The SOFC has not yet reached market maturity. This presentation focuses on the possibilities for manufacturing SOFCs with high power outputs and long-term durability by using manufacturing technologies feasible in industry. For the past 15 years, FZ Jülich has been developing large-size so-called anode-supported SOFCs (up to 200 x 200 mm²) with reproducibly high power output (> 2 A/cm² at 800°C). Novel technologies for high-capacity manufacturing such as tape casting and roller coating have been introduced. Additionally, newly developed thin-film techniques have led to power outputs of more than 3 A/cm² at 800°C and more than 1.5 A/cm² below 700°C. These high power densities open up new possibilities for the operation of SOFCs at low temperatures to ensure low degradation and therefore long lifetimes.

Influence of Processing Parameters on the Manufacturing of Anode-Supported Solid Oxide Fuel Cells by Different Wet Chemical Routes

Anode-supported solid oxide fuel cells (SOFC) are manufactured at Forschungszentrum Jülich by different wet chemical powder processes and subsequent sintering at high temperatures. Recently, the warm pressing of Coat-Mix powders has been replaced by tape casting as the shaping technology for the NiO/8YSZ-containing substrate in order to decrease the demand for raw materials due to lower substrate thickness and in order to increase reproducibility and fabrication capacities (scalable process). Different processing routes for the substrates require the adjustment of process parameters for further coating with functional layers. Therefore, mainly thermal treatment steps have to be adapted to the properties of the new substrate types in order to obtain high-performance cells with minimum curvature (for stack assembly). In this presentation, the influence of selected process parameters during cell manufacturing will be characterized with respect to the resulting physical parameters such as slurry viscosity, green tape thickness, relative density, substrate strength, electrical conductivity, and shrinkage of the different newly developed substrate types. The influencing factors during manufacturing and the resulting characteristics will be presented and possible applications for the various substrates identified.

Development of Thin-Film Manufacturing Technologies for Solid Oxide Fuel Cells and Gas Separation Membranes

The development of solid oxide fuel cells (SOFCs) and gas separation membranes for fossil (fuel?) power plants has previously suffered from cost issues like the manufacturing of the core components including i) the ceramic fuel cell and ii) the ceramic membrane, and from insufficient power density (current density or flow rate) on the stack, module or system level. Forschungszentrum Julich has been working on SOFC development for 20 years, and on membrane development for 6 years. Both energy-related applications are based on similar materials systems, similar micro-structural features (porous-dense, coarse-fine), comparable application parameters (e.g. high temperature) and are manufactured with similar technologies. In the past the focus laid mostly on basic materials research and proving the functionality of the membranes or fuel cells. Meanwhile, one key topic has been the application of low-cost thin-film high-throughput manufacturing technologies. This includes the fabrication of the supports (mostly...