Mechanism of Cr deposition and its application in the development of Cr-tolerant cathodes of solid oxide fuel cells

It is well known that at solid oxide fuel cells (SOFCs) operating temperatures, volatile Cr species are generated over the chromia scale of chromia-forming alloy interconnect, poisoning the cathodes such as (La,Sr)MnO3 (LSM) and (La,Sr)(Co,Fe)O3 (LSCF) and causing the rapid degradation of the cell performance. Thus, SOFCs based on the chromia-forming alloy interconnect require the development of cathode not only with high electrochemical activity but also with the high Cr-tolerance. In the last 7–8 years, we studied, in detail, the interaction between the Cr–Fe alloys and SOFC cathodes. In this paper, the mechanism of Cr deposition at LSM and LSCF cathodes is briefly reviewed. Based on the reaction mechanism, a strategy to develop Cr-tolerant cathodes for SOFCs is proposed.