Kevin Schiemann

 

Chrome poisoning of non-manganese containing cathode materials for solid oxide fuel cells (SOFCs)

Schematic structure incl. working principle of SOFCs

In times of progressive industrial globalization and a steady demand for fossil fuels (by continuous shrinkage of their occurrences), resource-efficient alternatives gain much in importance. In direct comparison to ordinary combustion technologies, fuel cell systems (e.g. SOFCs) show higher efficiencies by converting chemical energy directly into electrical energy.Despite continuous improvements in the manufacturing processes, in the materials being used as well as in the cell designs were made, commercialization of most of these fuel cell types remained low. In order to successfully commercialize solid oxide fuel cells (SOFCs), one of the main goals is represented by the provision of better long-term stabilities and thus detailed understanding of arising degradation mechanisms. For this reason the mechanisms of chrome poisoning of cobalt and iron containing cathode materials (LSCF) should be identified and compared to those of traditional LSM cathodes. Therefore appropriate SOFCs have to be produced and characterized electrochemically in presence as well as absence of a chromium source. Besides electrochemical characterizations also microstructural, chemical and crystallographic investigations should be performed to evaluate variations and derive reasons for cathode degradation. In the end it should be possible to formulate recommendations with regard to the optimal cathode composition.