Material and fabrication challenges in the development of monolithic solid oxide fuel cells

The authors discuss material properties, material requirements, and fabrication issues in the development of the monolithic solid oxide fuel cell (MSOFC). The MSOFC is composed of a honeycomb of very small cells, each 1 to 2 mm in diameter. The walls of the honeycomb are formed from thin (25 to 100 μm) ceramic layers of four cell components. The MSOFC imposes stringent requirements for stability, conductivity, compatibility, and thermal properties of the constituent materials at the operating temperature of about 1000°C. Successful fabrication of an MSOFC depends on incorporating the materials into a self-supporting structure at a higher sintering temperature. A fabrication scheme for the MSOFC must incorporate each material in such a way that conditions at each fabrication step will not destroy desired material characteristics of any of the component layers. Materials development for the cathode, anode, electrolyte, and interconnect is discussed, and the tape casting and tape calendering fabrication processes are examined