Thermal Expansion Studies on Cathode and Interconnect Oxides*

The thermal expansion of both the cathode and interconnect of the high temperature solid oxide fuel cell is reviewed. The influence of dopants such as Al, Mg and Sr are discussed. Data are presented which suggest that Sr doped LaCrO 3 matches the thermal expansion of zirconia best, but this composition is more susceptible to expansion upon reduction than Mg doped LaCrO 3 . Data also show that Sr doped LaMnO 3 has too high of a thermal expansion coefficient and that to make a structurally sound cathode, alternate compositions need to be considered.