Materials selection for solid oxide fuel cells

The materials selection and materials development for solid oxide fuel cells (SOFCs) is driven by the operating conditions and the type of application. Therefore several different types of SOFCs are currently under development and can be classified according to different operating temperature regimes, the unit size raging from a few kilowatts to megawatts as well as stationary or mobile applications. SOFC stacks consist of various components which have to be adjusted and optimized in terms of thermal expansion, chemical interaction at their interfaces, electronic and ionic conductivity and electrochemical performance. Besides the fuel cells, interconnecting plates, contact layers and sealings have to be developed in planar SOFC stack designs. This contribution reviews the current situation in SOFC materials development, gives examples of materials solutions achieved and summarizes the challenges still to be solved.