Perspective and control of cation interdiffusion and interface reactions in solid oxide fuel cells (SOFCs)

The occurrence of cation interdiffusion during sintering and operation of Solid Oxide Fuel Cells (SOFCs) is inevitable, due to high temperatures and chemical potential gradients. Cation interdiffusion may be followed by solid state reaction, resulting into the formation of secondary phases. Understanding of the factors that trigger the occurrence of cation interdiffusion and interface reactions is crucial towards controlling their occurrences. Here, we have discussed the phenomena associated with cation interdiffusion in solid oxide fuel cells. We have established that cation interdiffusion and interface reactions occur both during the high temperature sintering and during SOFC operations. Case examples where cation interdiffusion and subsequent interface reactions form secondary phases are discussed. The various methods that can be used to minimize or control the occurrence of cation interdiffusion are discussed: the use of diffusion barriers, fabrication of strontium free cathode materials, lowering the sintering temperature and the SOFC operating temperature.

Automated summary

The occurrence of cation interdiffusion in solid oxide fuel cells (SOFCs) during sintering and operation is inevitable due to high temperatures and chemical potential gradients. This can lead to the formation of secondary phases through solid state reactions. Understanding the factors that trigger cation interdiffusion and interface reactions is crucial for controlling their occurrences. Various methods, such as the use of diffusion barriers, strontium-free cathode materials, and lower sintering and operating temperatures, can be used to minimize or control cation interdiffusion.