Strategy of the Development of Cr-tolerant Cathodes of Solid Oxide Fuel Cells

Abstract

The significant development of solid oxide fuel cells (SOFCs) operating in the intermediate temperature range of 600-800oC enable the use of cheap alloys as metallic interconnects. However, at the SOFC operating temperatures, the volatile Cr species are generated over the chromia scale, poisoning the cathodes such as (La,Sr)MnO3 (LSM) and (La,Sr)(Co,Fe)O3 (LSCF) and leading to the rapid degradation of the cell performance. Thus, the development of Cr-tolerant SOFC cathode is important for the SOFCs with metallic interconnect. In this work, a strategy based on our systematic studies of the Cr deposition process under SOFC operating conditions is proposed. Based on this strategy, Mn- and Sr-free materials are developed as Cr- tolerant cathodes. Initial results show that Mn and Sr-free materials such as La(Ni,Fe)O3 and (La,Ba)(Co,Fe)O3 have very stable performance and Cr deposition at La(Ni,Fe)O3 and (La,Ba) (Co,Fe)O3 cathodes is substantially retarded as compared to that on LSM and LSCF cathodes.