474724 High Performance LT-SOFC Based on a Strontium Iron Cobalt Molybdenum Oxide Based Ceramic Anode Support

Monday, November 14, 2016: 1:00 PM
Powell (Hilton San Francisco Union Square)
Ke-Ji Pan, Colin Gore, Lei Wang, Luis Correa, Thomas Langdo and Bryan Blackburn, Redox Power Systems, College Park, MD

High Performance LT-SOFC Based on a Strontium Iron Cobalt Molybdenum Oxide Based Ceramic Anode Support

Ke-Ji Pan, Colin Gore, Lei Wang, Luis Correa, Thomas Langdo, and Bryan Blackburn

Redox Power Systems, LLC

College Park, MD 20742

Abstract

Solid Oxide Fuel Cells (SOFCs) consisting of a ceramic anode have several advantages when compared to a traditional Ni-cermet based anode. The main advantages include better red-ox cycling stability and chemical stability with the use of hydrocarbon fuels. However, ceramic materials, such as Nb or La doped SrTiO3, are much less conductive than Ni. Furthermore, such materials usually display appreciable conductivity only after a high temperature reduction step, thus practically limiting their use to higher operating temperatures. Unfortunately, the catalytic activity of ceramic anodes is not typically as good as Ni. At low operating temperatures fuel oxidation kinetics are hindered and must be improved through the infiltration of catalysts. In addition, ceramic anode-supported SOFCs have more fabrication difficulties than Ni-cermet cells, such as the potential for chemical reactions between cell components, thermal mismatch, and shrinkage mismatch. Therefore, until now there have been very few reports of ceramic anode-supported LT-SOFCs.

In this work, we have successfully synthesized new strontium, iron, cobalt, molybdenum oxide ceramic anode materials with different compositions (SFCM#1-#5) and fabricated anode-supported SOFCs using GDC as the electrolyte. SFCM displays a conductivity greater than 30 S*cm-1 between 450 ¡ãC to 650 ¡ãC without the need for a high temperature reduction step, as shown in Figure 1. Button cells have been fabricated and demonstrated a power density greater than 0.4 W/cm2 at 500 ¡ãC and have shown good stability in H2/CH4 mixtures for several hundred hours. We have scaled up the size of the cells to greater than 5 cm by 5 cm (Figure 2) and will discuss additional performance results and future challenges as we work towards integrating the ceramic anode cells into an LT-SOFC stack.

Figure 1. Conductivities of various SFCM compositions in 10% H2 / 90% N2

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Figure 2. Scaled-up SFCM ceramic anode SOFC.

Key Words: LT-SOFC, ceramic anode, high performance, long term stability


Extended Abstract: File Not Uploaded
See more of this Session: Solid Oxide Fuel Cells (SOFC) and Electrolyzers
See more of this Group/Topical: Transport and Energy Processes