Last modified: 2014-10-08
Abstract
Long-term performance stability is one of the most critical issues in the development of high temperature solid oxide fuel cells (SOFCs) technologies. One of the main factors which influence the durability of SOFCs is the degradation of electrochemical activities of electrodes by the contaminants such as volatile chromium, boron and sulfur species in the air streams either due to the use of metallic interconnect and glass sealants or from the environmental air. For example, for SOFCs using chromia-forming alloy as metallic interconnect, volatile Cr species are generated over the chromia scale, poisoning the SOFC cathodes such as (La,Sr)MnO3 (LSM) and (La,Sr)(Co,Fe)O3 (LSCF) and causing a rapid degradation of the fuel cell performance [1,2]. In addition to chromium deposition and poisoning, the presence of volatile boron from borosilicate based sealants and sulfur species from environmental air can also significantly deteriorate the electrocatalytic activity of SOFC’s cathode and decrease the cell power density [3-7]. Thus, a fundamental understanding of the interaction between the common contaminants such as chromium, boron, sulfur and SOFC cathodes is essential for the development of SOFCs with high performance and high durability and stability.
In this presentation, the latest progress in the understanding of the mechanism and kinetics of the contaminant deposition and poisoning at the SOFC cathodes will be briefly reviewed. In particular, the challenges and future development of more contaminant tolerant cathodes will be discussed.Keywords
References
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