Development of Practical Size Anode-Supported Solid Oxide Fuel Cells with Multilayer Anode Structures

Abstract

We have developed anode-supported solid oxide fuel cells (SOFCs) using and scandia-alumina–stabilized zirconia (SASZ) for the cathode and electrolyte, respectively, and employing a mixture of NiO and SASZ for the anode. Anode-supported SOFCs were fabricated using two types of NiO powder with different sintering characteristics to control the anode structure. The cells with anodes made from fine NiO powder provide high power performance, while those with anodes made from coarse NiO powder show good gas diffusion characteristics. Combining the merits of these anodes, we successfully fabricated a cell that simultaneously exhibits high power generation characteristics and smooth gas diffusion through the anode substrate. Moreover, by controlling the cell construction, we minimized the cell warpage. The single cell stack performance when using a metallic alloy manifold showed that the power increased with reduced cell warpage. We fabricated 60, 100, and cells and obtained high electric power from a single cell stack, which was nearly proportional to the cell size. These cells exhibited an electrical conversion efficiency of 53% lower heating value (LHV) when using hydrogen as a fuel. A long-term stability test was also successfully performed over .