Preparation of thin films using the tape-casting process for use in the solid oxide fuel cell

Solid oxide fuel cells (SOFCs) produce electricity by electrochemically combining hydrogen and oxygen to give water. They operate at high temperatures (typically 1000 °C) allowing natural gas (hydrogen source) to be reformed in the cell rather than in an external reformer, reducing cost. Comparison with current electrical power generation systems, show SOFCs to have increased efficiencies, reduced NO_x and SO_x emissions and improved reliability promising a viable future alternative for electricity production. Thin ceramic films to less than 200 µm are necessary for reduced all resistance. Tape casting is one method for production of thin ceramic (or metallic) films. In this paper, tape casting was used to produce both dense and porous thin films of 8-mol% Yttria stabilised Zirconia (YSZ). The films were fired both separately and together in a monolithic multi-layered block in order to determine the feasibility of using this method for the production of all components of the SOFC. The effects of organic content, addition of pore-forming agents and firing temperature on the microstructure of the films were investigated. Each individual layer produced was between 40–60 µum thick, with the highest density being>97% and the highest porosity obtained at 30% (produced by addition of a pore former). No de-lamination was observed upon heating the multi-layers.