APPLICATIONS OF TECHNOLOGY:

• Planar solid oxide fuel cells
  
• Planar gas separation devices
  
• Planar membrane reactors

ADVANTAGES:

• Produces high-quality thin films with no warping or cracking
  
• Solid oxide fuel cells fabricated with this method show exceptional performance at reduced temperatures
  
• Minimal or no compressive loads required for sintering
  
• A wide variety of conductors can be deposited with minimal or no alteration of fabrication equipment
  
• Requires only small amounts of bilayer fabrication material, making it suitable for expensive conductors

ABSTRACT:

Craig Jacobson, Lutgard DeJonghe, and Steven Visco have invented an improved colloidal deposition technique whereby high-quality films of a wide variety of ionic and mixed ionic-electronic conductors can be deposited on highly-porous electrode substrates. They have discovered that in order to fabricate large area, flat, bilayered plates, it is necessary to have exceptionally good homogeneity of substrate and film, as well as similar (well matched) sintering rates and total shrinkage to avoid warping of the bilayer during firing. The electrolyte is applied by aerosol spraying (as opposed to reverse slip casting.) This allows for improved control and uniformity of the green or pre-sintered density and film thickness. Bilayers can be freely sintered to a high degree of flatness with minimal or no compressive load. Thin-film solid oxide fuel cells (SOFCs) fabricated using these techniques have demonstrated exceptional performance at reduced temperatures relative to conventional thick-film SOFCs.

STATUS:

• U.S. Patent #6,458,170. Available for licensing

REFERENCE NUMBER: IB-1305

FOR MORE INFORMATION PLEASE SEE:

• V. E. J. van Dieten and Schoonman J., "Thin film techniques for solid oxide fuel cells", Soid State Ionics, 1-2, 57, 141-145, 1997.
• S. de Souza, Visco S. J., L. C. De Jonghe, "Reduced-Temperature Solid Oxide Fuel Cell Based on YSZ Thin-Film Electrolyte", journal of the electrochemicl society, 144, 3, 1997.

SEE THESE OTHER BERKELEY LAB TECHNOLOGIES IN THIS FIELD:

• Fail-Safe, Inexpensive Electrochemical Device Stack Design, IB-1658A
• High Quality, Dense Thin Films Using Metal/Metal Alloy Additives, IB-1654
• Improved Electrode-Electrode Structures for Solid State Electrochemical Device, IB-1405
• Inexpensive Production of High Density Thin Ceramic Films on Rigid or Porous Substrates, IB-1302
• Low Cost Fabrication of Thin-Film Ceramic Membranes for Nonshrinking Substrates, IB-1304
• Metal Current Collector Protected by Oxide Film, IB-1656
• Novel Support Structure for Ceramic Electrochemical Devices, IB-1418
• Support for Planar Solid State Electrochemical Devices, IB-1790
• Surface Additives for Enhanced Electrode Performance, IB-1406