Novel Surface-Functionalized Powders for Solid Oxide Fuel Cells

Statement of the Problem or Situation that is Being Addressed - Solid oxide fuel cells (SOFCs) offer exceptional promise for electrical power generation with reduced carbon footprint, but SOFC reliability must be improved for the technology to be widely commercialized. Strontium based ceramic cathodes e.g. lanthanum strontium iron cobalt oxide (LSFC) enable good performance, but cathode degradation occurs during operation at elevated temperatures, and contributes to degradation of long-term SOFC performance. Statement of How this Problem is Being Addressed Reliability of SOFC cathodes has been improved by infiltrating a coating into to the cathode after fabrication of the SOFC stack. Many experts believe that this approach suppresses Sr migration to the cathode surface. This approach, however, adds to processing complexity and cost. Sonatas approach is to precisely form a Sr impervious barrier on the LSMF particles prior to sintering. Statement of What will be done in Phase I - In Phase I, Sonata will demonstrate an ultra-high precision ALD process to deposit gadolinium doped ceria (GDC) on the surface of LSFC powder particles prior to sintering; GDC thickness will be 1-5 nm. This core-shell structure is expected to reduce deleterious Sr diffusion during SOFC operation, while maintaining cathode sintering properties. Sonata will collaborate with FuelCell Energy and University of South Carolina to demonstrate feasibility and performance of the cathodes fabricated using this improved constituent powder. Sonata will also perform a detailed cost analysis of the proposed cathode powder production process. Commercial Applications and Other Benefits GDC-LSMF core shell cathode powders are expected to dramatically increase SOFC reliability, which will multiply the demand and applications of the technology, and leverage the expanding supply of natural gas and other fuels in the U.S. Once the technology is established, other thermal barrier applications may benefit from this technology, particularly for use in engines and turbines, leading to increased efficiency. Key Words SOFC, cathode, LSCF, GDC, ALD, core-shell Summary for Members of Congress Solid oxide fuel cells, SOFCs, are ultraclean electrical power generators that utilize natural gas and other fuels. This SBIR project is investigating how to dramatically increase their reliability by using advanced, cost effective technology. This low cost technology will result in widespread adoption of cleaner power sources and increase the U.S. manufacturing base.