Thermophysical Properties of Materials for Solid Oxide Fuel Cells (SOFC)

The data of heat capacity, thermal conductivity, and thermal expansion behavior for materials in solid oxide fuel cells (SOFCs) are reviewed. Most of the SOFC materials are complex metal oxides and their thermal conductivities are generally low, that causes a large temperature distribution during the operation. Since the SOFC consists of metal oxides and composites, a good thermal expansion matching is the most important point in order to fabricate durable cells and stacks. The electrolytes and interconnects are exposed in a large gradient of oxygen partial pressure at a high temperature, and isothermal expansion is observed for rare earth substituted ceria and alkaline earth substituted lanthanum chromites. Although the isothermal expansion in lanthanum chromites can be alleviated by substituting the transition metals, it can not in rare earth substituted ceria. 解　説