Novel advanced solid oxide fuel cells based on ceria-halide salt composite electrolytes

Novel ceria-salt composite ceramic electrolytes developed recently have demonstrated an enormous potential on developing advanced intermediate temperature (IT, 400 - 800degreesC) solid oxide fuel cell (ITSOFCs) technology for both tractionary and stationary power applications. These new materials and related TISOFC technology are changing the strategy of the SOFC R & D, and accelerating the SOFC commercialization., This paper especially reports several types of the ITSOFCs based on the ceria-halide composite electrolytes. Among various halide salts the alkaline/alkaline earth chloride and fluoride fuel cells showed the best performance. It has been achieved this far that these fuel cells reached a power density between 200-600 mWcm(-2) at a current density of 400-1000 mAcm(-2) in the IT region. These excellent ITSOFC performances demonstrated a very advanced SOFC technology for intermediate temperatures. Both proton and oxygen ionic conduction may exist in these new oxide-salt composite ceramic electrolytes since, during the fuel cell operation, water was observed at both anode and cathodes but in most cases, water was formed more at the anode side. This mixed proton and oxygen ion conducting materials open a new subject for both fundamental and applied research.