CCS and Power Systems
Advanced Energy Systems - Solid Oxide Fuel Cells
Unraveling the Role of Transport, Electrocatalysis, and Surface Science in the Solid Oxide Fuel Cell Cathode Oxygen Reduction Reaction
Performer: Trustees of Boston University
Project No: FE0009656
Boston University will build on prior Solid State Energy Conversion Alliance support by employing a combination of experimental and computational tools to develop newer cathode and electrocatalyst materials employed in increasing levels of complexity:
- Fabrication of micropatterned cathode thin films and heteroepitaxial thin films (crystalline films grown by deposition on differing crystalline material) of various cathode materials on suitably chosen electrolyte substrates.
- Use total reflection X-ray fluorescence and hard X-ray photoelectron spectroscopy to probe the surface composition and oxidation states and the chemical environment of the surface cations and anions.
- Use point defect models to relate compositional changes to changes in oxygen vacancy concentrations and distribution of oxidation states for multivalent elements such as manganese.
- Experimentally measure surface exchange and diffusion coefficients using the oxygen isotope 18O.
- Use AC impedance spectroscopy on micropatterned electrodes of selected cathode materials, with transport phenomena modeling using MATLAB-SIMULINK and/or COMSOL.
- Use transmission electron microscopy to probe the buried interfaces between the cathode and electrolyte before and after polarizing the interface.
- Use density functional theory to calculate the most facile pathways for the oxygen reduction reaction (ORR) on several cathode material surfaces, while also exploring the rates of the ORR under various experimental conditions.
- Use experimental and theoretical research on thin film cathodes to narrow choice of cathode material and composition.
- Fabricate and test single cells using selected cathode materials. The power density and performance degradation metrics will be used to evaluate cathode material and composition.
- Use polarization loss modeling to deconvolve (i.e., disentangle mixed information) the cathodic concentration and activation polarization values.
- Characterize porous microstructure of the cells to quantify the effective surface area and triple phase boundary length.
- Optimize materials choice and cathode microstructure to demonstrate a 50 percent improvement in performance.