The National Energy Technology Laboratory's Solid Oxide Fuel Cell Experimental Laboratory (SOFCEL) characterizes the performance and operation of single cells and small stacks. The laboratory is equipped with several test stands capable of evaluating solid oxide fuel cells (SOFC) at pressurized conditions and temperatures up to 1000°C. NETL's onsite researchers support the Solid State Energy Conversion Alliance (SECA) Program with advanced models and simulations that can predict detailed thermal, fluid, solid-mechanic, and electrochemical phenomena for fuel cell analysis and design.

The research portfolio includes basic and applied research to assess the effects of contaminants on SOFC cell degradation and performance, and to developing durable high temperature and sulfur-tolerant anode materials. This type of research is important in order to apply SECA-developed technology to future coal-based power systems.

Solid-mechanic phenomena (stress-strain) within the fuel cell are significant for materials evaluation. Therefore, SOFCEL researchers also work closely with internal and external sensors developers to overcome challenges such as high temperature environments, hydrogen-containing explosive gases, small flow channels, and limited ability to access cells and components. Research objectives are to apply sensors on the electrolyte, anodes, cathodes, and on stack hardware seals and interconnects to measure temperature, strain, and heat flux.

SOFCEL researchers also have developed expertise to investigate the dynamic performance of high temperature fuel cells. The researchers have developed new dynamic modeling tools and performed basic experimental studies to examine the effects of load change on cell behavior. Such work has identified, for example, how sudden large load loss (such as in an emergency stop) can induce unique operating modes such as reverse current conditions.

Recent research efforts have also examined the use of micro-electro-mechanical-systems (MEMS) for fuel cell applications. Models have been developed and components have been fabricated to evaluate the potential of MEMS technology to improve the flow and energy management of fuel cells.

Other work has investigated the effects of current collection geometry on cell performance, and has showed how sufficient density of collection contact points is required to avoid cell performance degradation.

Finally, SOFCEL researchers are supporting U.S. industry through a collaboration to develop guidelines and standards for fuel cell testing. Industry has recognized this as a need to more efficiently communicate test results and make the results more relevant to the ongoing need to improve the reliability and durability of SOFC technology.

SOFCEL technical specifications include:

• Button cell testing
• 10cm x 10cm cell testing
• Low and high temperature fuel cell technology
• Pressure capable to 90 psig
• Temperature to 1000^o C
• Current-interrupt and spectral impedance analysis
• Models for cell steady state and dynamic performance prediction at both the button cell and full cell level using:
  • H₂ and CO electrochemistry
  • Contact resistance for cell components
  • Species diffusion in flow channels and porous media
  • Water-gas shift reaction
  • Internal reforming
  • ANSYS FEA analysis

For more information contact Randall Gemmen