Cr-based alloy used as interconnect in solid oxide fuel cells

The status of Cr-based alloy used as interconnect in solid oxide fuel cell (SOFC) was mainly reviewed in this paper. Cr-based alloy is one of the most important materials in SOFC because of its high oxidation resistance, corrosion resistance and electrical conductivity. At cathode of SOFC, it is easy to form the oxidation scale. Simultaneously, the diffusion and volatilization of Cr may lead to the poisoning of cathode. It has been indicated that the formation of Cr2O3 scale would be restrained by the addition of lanthanon such as Y, La, Ce and Zr. However, at anode, the performances of Cr-based alloys are better than that of an cathode. Comparing to the Al2O3, NiO, MgO and TiO2, Cr2O3-based scale is of good general performances such as high temperature resistance (1100°C), the similar thermal expansion coefficient(TEC)(9.6×10-6 K-1) to YSZ electrolyte (10.8×10-6 K-1) and high electrical conductivity. Presently, the oxide dispersion strengthened (ODS) alloys domain the trends of Cr-based alloys used in SOFC, in which the most representative material is Cr5Fe1Y2O3, with the TEC (9-10)×10-6 K-1(1000°C) and high oxidation resistance.