From powder properties to fuel cell performance – A holistic approach for SOFC cathode development

This paper provides a short overview on the different aspects of SOFC materials, especially of new cathode materials, ranging from considerations of material properties to long-term phenomena after cell operation. Special emphasis is laid on the reproducible manufacturing of cathode microstructures, which has to be optimised for each individual composition or powder quality. If this is not performed a comparison of various cathode materials can be misleading. The microstructure can be tailored by varying the sintering conditions, which results in different particle sizes. Besides the improvement of power density, the long-term stability of cathodes is discussed in more detail. For (La,Sr)(Co,Fe)O3 (LSCF) cathodes, the predominant factor determining voltage losses during cell operation is the temperature. The mechanism responsible for voltage deterioration is a slow decomposition of the LSCF perovskite due to partial de-mixing of strontium.