Solid oxide fuel cells (SOFCs) show significant promise as highly efficient, fuel flexible, solid-state energy conversion devices, but they are complex material systems that require high temperature and gas separation for optimal operation. This also makes SOFCs difficult to pinpoint how they degrade, whether because of the intrinsic nature of the materials chosen or because of contaminants in the fuel or oxidant stream.
Operando and in situ x-ray absorption spectroscopy (XAS) provide element-specific information on the chemical phenomena responsible for performance deficiencies, such as poisoning, new phase formation, or transient surface species. Both the local and electronic structure of transition metal and rare earth cations can be studied via synchrotron facilities available at national laboratories, including the National Synchrotron Light Source (retired 2014) and Light Source II at Brookhaven National Laboratory and the Advanced Photon Source at Argonne National Laboratories. Additionally, low energy soft x-rays from those facilities can be used to study surface phenomena or low atomic number elements like oxygen and sulfur. This project is focused on developing in situ and operando x-ray techniques for the challenging experimental conditions necessary for solid oxide fuel cell operation. In complement with other x-ray characterization techniques, such as diffraction and photoelectron spectroscopy, x-ray characterization is aimed at fundamentally understanding degradation phenomena and using that information to rationally design novel and higher performing materials.