APPLICATIONS OF TECHNOLOGY:

• Tubular solid oxide fuel cells
  
• Ceramic membrane fabrication
  
• Electrolytic separation

ADVANTAGES:

• Produces high quality films on non-shrinking substrates
  
• Scalable for low cost industrial production
  
• Minimum number of processing steps
  
• Enables sintering at lower temperatures by increasing the green (pre-sintered) density of the film

ABSTRACT:

Certain fuel cell manufacturing specifications require deposition of a thin ceramic membrane onto a substrate that doesn't shrink over it's lifetime. Pre-firing the substrate improves substrate reliability and may lower its cost. This requires a film that has minimal volume change during drying and sintering. Craig Jacobson, Steven Visco, and Lutgard DeJonghe have discovered that by systematically adjusting the concentration of suspended particles and current density /voltage used in electrophoretic deposition (EPD), they can produce high density green (pre-sintered) films that can be dried and sintered onto a non-shrinking substrate without cracking or delaminating. This method has the potential for large-scale, cost-effective production.

The Berkeley Lab method has a combination of characteristics that make it preferable to other methods of applying films to non-shrinking substrates. Unlike electrochemical vapor deposition, which is inherently a capital intensive batch process, the Berkeley Lab method is inexpensive and scalable. In contrast to films produced using colloidal deposition, the green films fabricated with the Berkeley Lab EPD method are highly dense and only shrink minimally during sintering, thus eliminating cracking and delamination. Conventional EPD methods produce films with lower green densities leading to cracking during drying and/or sintering due to the large volume change of the film relative to the non-shrinking substrate.

STATUS:

• U.S. Patent #6,887,361
• available for exclusive or non-exclusive licensing within all fields of use with the following exception: only available for non-exclusive licensing within the field of use covering preparation of industrial gases and organic chemicals produced through electrolytic separation by means of a membrane.

REFERENCE NUMBER: IB-1304

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
• Metal Current Collector Protected by Oxide Film, IB-1656
• Method for Making Flat, High Performance Thin Membrane Structures on Porous Substances, IB-1305
• 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