Development of Porous Metal-supported Solid Oxide Fuel Cells

Abstract

<p>The introduction of metal supported cells may be a key innovation in the development of solid oxide fuel cell (SOFC) technology. The objective of this study was to develop a process of co-firing the ceramic layers of a solid oxide fuel cell attached to their porous metal support. This is a major departure from the traditional fuel cell architecture where the support layer is a ceramic composite made of YSZ and NiO.</p> <p>The problems to be eliminated during the fabrication process include the warping, cracking and delamination of the cell during the co-sintering process.</p> <p>In this study, the porous metal layer was produced by the freeze tape casting process. During co-sintering, it is necessary to match the relative shrinkage between the metal and ceramic layers. Different parameters which can influence the relative shrinkage were explored, including the heating rate, sintering temperature, sintering time, cell thickness, solid loading of the green tapes, applications of wet and dry hydrogen in the sintering atmosphere, as well as a change of the electrolyte material. Specifically, GDC was tested as an alternative electrolyte to YSZ.</p> <p>Since the porous metal substrate is exposed to air during fuel cell operation, it must be protected from oxidation. Therefore, the pack cementation method was used to apply a layer of aluminum onto the metal substrate. Variables such as temperature and exposure time of the coating materials were investigated in this thesis.</p>