Surface segregation and poisoning in materials for low-temperature SOFCs

Surfaces and interfaces determine the performance and long-term durability of solid-oxide fuel cells (SOFCs). In most cases, the surface chemical composition of the materials used in these electrochemical energy conversion devices shows significant deviations from the bulk chemistry. This might be as a result of surface cation segregation processes, as well as long-term surface poisoning due to external impurities. Both processes have implications for the electrochemical performance of the devices, leading to the degradation of the cell components. In order to suppress this degradation, an effort to lower the operation temperature to 500–800°C has been made. This article provides an overview of present research progress related to surface segregation and poisoning for low-temperature SOFCs.