Oxidation behavior and interface diffusion of porous metal supported SOFCs with all plasma sprayed functional layers in air at 65OoC

metal supported solid oxide fuel cells (PMS-SOFCs) are regarded as a promising choice for power generation. 430 L steel is a popular choice for SOFC support due to its acceptable electrical performance and stability while offering very-low cost. In this study, we investigate the oxidation kinetics of 430 L porous support and interface between anode and support of plasma sprayed PMS-SOFCs in air at 650 degrees C. The effect of exposure time on the microstructure and phase is studied. The metal support has a mass gain of similar to 1% after 500 h exposure because a continuous Cr2O3 scale formed. The element diffusion across the interface of anode and support is characterized. Thin and continuous scales are found at the interface and hinder the diffusion of Cr. The thickness of oxide scale and Cr diffusion distance is less than 1 pm after 500 h oxidation. In general, the oxidation at 650 degrees C is found to be acceptable. Moreover, a decrease of maximum power density from 0.47 to 0.40 W cm(-2) at 650 C is found after 500 h oxidation, indicating that sacrificing 16% of initial power density could acquire a continuous Cr2O3 scale. The increase of ohmic and polarization resistance should be the reason to the cell performance degradation.

Automated summary

In this study, the oxidation kinetics of 430L porous support in PMS-SOFCs was investigated, showing a 1% mass gain after 500 hours of exposure at 650 degrees C due to the formation of a continuous Cr2O3 scale. Diffusion of elements across the interface of the anode and support was hindered by thin and continuous scales, with less than 1 µm thickness after 500 hours of oxidation. The decrease in maximum power density after 500 hours of oxidation was attributed to the formation of a continuous Cr2O3 scale and an increase in ohmic and polarization resistance.