NU 2000-063

Inventors

Scott A. Barnett*

Jiang Liu

Short Description

New design and method for fabrication of a hydrocarbon fuel cell that accomplishes direct oxidation of fuels without carbon deposition

Abstract

Northwestern researchers have devised a new solid oxide fuel cell construct that combines the advantages of conventional tubular structures with planar stacking designs. The integrated solid oxide fuel cell (ISOFC) is well-suited for hydrogen or direct hydrocarbon oxidation. While current tubular cell stack designs minimize seal and manifold problems, they still exhibit poor cell-to-volume efficiency resulting in significant ohmic losses. Planar cell stack configurations, on the other hand, provide greater power-to-volume ratios but are mechanically less robust and require excellent seals. The ISOFC developed in this invention incorporates the advantages of planar as well as tubular designs in a stacked fuel cell. The integrated configuration has a flattened tube with a seal-less cell design that eliminates interconnects which ultimately results in reduced electrical losses and provides greater overall stack performance. The ISOFC incorporates an improved partially-stabilized zirconia (PSZ) support composition exhibiting excellent porosity and mechanical properties, low leakage current, improved anode and cathode compositions, and simple screen printing patterning fabrication. Researchers have initiated product development and testing. A demonstrative ISOFC unit has been constructed and successfully operated at 700¬8C employing air and humidified hydrogen fuel. Processing and materials optimizations to utilize hydrocarbon fuels such as methane and ethane have also been accomplished.

Applications

• Power generation
• Clean and alternative energy

Advantages

• Greater power densities at lower operating temperatures
• No carbon deposition
• Fewer seals and reduced electrical losses
• Optimal mechanical properties
• Greater overall cell-to-volume efficiency
• Straightforward fabrication process
• Scalable unit manufacturing

IP Status

Issued US patents 6,479,178 and 7,709,124. International patent application has been filed.