Recent Advances to the Development of Low-Temperature Solid Oxide Fuel Cells

While existing solid oxide fuel cell (SOFC) technology has demonstrated much higher energy efficiency with minimal pollutant emission than the conventional technologies, the costs of the current SOFC systems are still prohibitive for broad commercialization. To be economically competitive, both the cost of materials and the cost of fabrication must be dramatically reduced. One effective approach to cost reduction is to reduce the operating temperature; many cell components, including interconnect, heat exchangers, and other structural or balance-of-plant components, can be fabricated from much less expensive materials when the operating temperature is sufficiently low. However, the interfacial polarization resistances increase rapidly as the operating temperature is reduced. This paper will address the critical issues in creating electrodes and interfaces of minimal polarization resistance in order to minimize internal electrochemical losses at low temperatures. In particular, design, fabrication, and characterization of composite electrodes consisting of silver and bismuth oxide will be discussed. Another approach to cost reduction is to reduce the cost of fabrication. Dense electrolyte films supported on porous anodes fabricated by screen-printing and dry press will be presented.