High-Temperature Electrochemistry and Functionalized Surfaces

The Molten Carbonate Fuel Cell (MCFC) is one of the most mature and efficient fuel cell technologies. The MCFC operates at high temperatures (580 up to 650°C), therefore, in contrast to low-temperature fuel cells, not only H₂ but also H₂+CO gas mixtures, natural or biogas can be used without noble metal catalyst. However, highly corrosive molten alkali carbonate electrolyte promotes degradation of the MCFC-components and limits their lifetime currently to approximately five years. Further lifetime extension is essential for a wide application of the technology and requires substantial efforts on the development of novel materials.

The research of the working group “Materials MCFC”, newly-founded in frame of the Fraunhofer Attract Program, is concentrated on addressing the following problems:

• Decreasing the solubility of matrix and cathode materials and reducing the particles growth in the carbonate melt with different additions
• Investigation of the wetting behavior of molten carbonates depending on their temperature and composition
• Quantitative understanding of molten electrolyte interaction with ceramic/metallic materials during the MCFC-operation

Resolving these problems will contribute not only to extending MCFC lifetime, but also to further development of materials for high-temperature thermal and electrochemical energy storage systems, whose performance critically depends on the interaction between corrosive melt and ceramic/metallic materials.

 

Services Offered

 

• Development of novel materials for systems with molten electrolytes
• Immersion tests of the powders in electrolyte melts
• Preparation and degradation tests of lab-scale cathode-, anode-half cells and stacks
• In-situ electrochemical impedance spectroscopy of the half-cells and stacks

 

Special Equipment

 

• High throughput test rigs for the characterization of:
  • Cathode and anode half-cells
  • Lab-scale MCFC-Stacks
  • Materials creep behavior
• Electrochemical impedance spectroscopy measurement stations