Solid Oxide Fuel Cells

Example of in situ transmission XAS experimental setup at Beamline X23A2 at NSLS.

Example of in situ transmission XAS experimental setup at Beamline X23A2 at NSLS.

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.

Schematic design for an operando fluorescence XAS experiment.

Schematic design for an operando fluorescence XAS experiment.

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.

 

An operando fluorescence XAS experiment in action.

An operando fluorescence XAS experiment in action.

A comparison of the results from both in situ and operando XAS experiments shows how significant and unique the material system's response is when studied under operating conditions. More information is at http://onlinelibrary.wiley.com/doi/10.1002/cssc.201402670/abstract

A comparison of the results from both in situ and operando XAS experiments shows how significant and unique the material system’s response is when studied under operating conditions. More information is at http://onlinelibrary.wiley.com/doi/10.1002/cssc.201402670/abstract

 

 

 

 

 

 

 

 

 

 

 

 

 

Literature:

Operando and In situ X-ray Spectroscopies of Degradation in La0.6Sr0.4Co0.2Fe0.8O3−δ Thin Film Cathodes in Fuel Cells

Enhancing SOFC cathode performance by surface modification through infiltration