Interaction between Crofer 22 APU Current Collector and LSCF Cathode Contacting Layer under Cell Operation

The metal interconnect oxidation and interaction with the cell are issues limiting the performances and the durability of the SOFC stacks. Despite the application of additional surface treatments or protective coatings such problematic are still affecting the system reliability because of hardly avoidable interactions since the operating conditions to which such material are exposed. Beside the high temperatures and oxygen partial pressures one should consider also the presence of a current load which acts locally changing the working conditions and the kinetic aspect of the  oxidation processes. In this work the current density effect has been investigated on Crofer 22 APU in air at 750°C. The same material has been pre-oxidized and coated with a state-of-the-art Co_1.5Mn_1.5O₄ spinel coating to test the effect of such treatments on the interaction with a La_0.6Sr_0.4Co_0.2Fe_0.8O₃ contacting layer simulating the interconnect interface at the cathode compartment. The behavior of such samples has been compared with the results on a working reproduction of a stack cathode compartment.