Innovative solid carbonate-ceria composite electrolyte fuel cells

An innovative solid carbonate-oxide composite and related fuel cell technology is reported. The solid carbonate-ceria composite (SCC) electrolytes were found to be highly conductive, with the material conductivity varying from 0.001 to 0.2 S/cm between 400 and 600°C. Fuel cells using these electrolytes reached a power density between 200 and 600 mW/cm2 at a current density of 300–1200 mA/cm2 in the same temperature range. The SCCs were found to possess both oxide-ion (originating from the ceria phase) and proton (from the carbonate phase) conduction. As an all-solid ceramic fuel cell, the SCC can effectively reduce the serious material corrosion problems suffered by molten carbonate fuel cells (MCFCs). On the other hand, the innovative fuel cell technology based on the SCC electrolytes developed in this work is similar to solid oxide fuel cells (SOFCs) and different from the MCFCs based on their ionic transport and fuel cell processes, which facilitates development of a new type of advanced fuel cell technology.