Joining and sealing of anode-supported planar SOFC stacks using glass and glass ceramics

摘要

Fuel cells are power converters to convert the chemical energy of fuels into electrical power directly and more efficiently than traditional electrical power generators. Solid oxide fuel cells (SOFCs) with an electrolyte made of yttria-stabilised zirconia (YSZ) operate at 800°C - 1000°C and have several advantages for stationary power conversion. At Forschungszentrum Julich a programme has been started to develop an anode-supported SOFC with a thin electrolyte (thickness 20 μm) in order to achieve larger cell areas and to decrease the operation temperature. Stacking of cells is necessary to obtain a voltage which is useful for technical applications. With the stack assembly sealings between fuel and oxidant as well as electrical contacts between the electrodes and the interconnect plate are necessary. For the sealing of SOFC stacks several joints between the electrolyte/anode unit, the metallic bipolar plates and to the manifold have to be made. Developments and solutions for these sealings made of glass and glass ceramic materials are presented as well as the assembly of SOFC stacks with up to 10 cells.