Metallization of bacterial cellulose for electrical and electronic device manufacture

• US 7,803,477 B2
• Filed: 08/19/2005
• Issued: 09/28/2010
• Est. Priority Date: 12/14/2001
• Status: Expired due to Fees

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Evans, Barbara R., O'Neill, Hugh M., Woodward, Jonathan, Jansen, Valerie Malyvanh
• Primary Examiner(s): Alejandro; Raymond
• Application Number:
  US11/207,431
• Publication Number:
  US 20050287420A1
• Time in Patent Office: 1,866 Days
• Field of Search: 429/40, 429/44, 429/2, 429/42, 502/101, 502/300, 502/326
• US Class Current: 429/535
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8817 Treatment of supports before application of the catalytic active composition coated porous composites H01M8/0245
• CPC Class Codes: H01M 4/8842 Coating using a catalyst salt precursor in solution followed by evaporation and reduction of the precursor
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: H01M 4/96 Carbon-based electrodes
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

A method for the deposition of metals in bacterial cellulose and for the employment of the metallized bacterial cellulose in the construction of fuel cells and other electronic devices is disclosed. The method for impregnating bacterial cellulose with a metal comprises placing a bacterial cellulose matrix in a solution of a metal salt such that the metal salt is reduced to metallic form and the metal precipitates in or on the matrix. The method for the construction of a fuel cell comprises placing a hydrated bacterial cellulose support structure in a solution of a metal salt such that the metal precipitates in or on the support structure, inserting contact wires into two pieces of the metal impregnated support structure, placing the two pieces of metal impregnated support structure on opposite sides of a layer of hydrated bacterial cellulose, and dehydrating the three layer structure to create a fuel cell.

Claims

1. A method for forming a fuel cell electrode, the method comprising:

providing an electrode support structure comprising bacterial cellulose; and

placing the electrode support structure in an acidic solution of a metal salt for a time period such that the metal salt is reduced to metallic form and the metal precipitates in or on the bacterial cellulose,

wherein the metal salt is selected from coordination compounds including a platinum metal group complex ion, and mixtures thereof wherein the electrode support structure comprises hydrated bacterial cellulose, and the method further comprises dehydrating the electrode support structure after the metal precipitates in or on the electrode support structure to form the fuel cell electrode.

2. The method of claim 1 wherein:

the metal salt is a coordination compound including a palladium complex ion.

3. The method of claim 1 further comprising:

simultaneously contacting the electrode support structure with a reductant fluid when the electrode support structure is placed in the solution of the metal salt.

4. The method of claim 3 wherein:

the reductant fluid includes hydrogen gas.

5. The method of claim 1 further comprising:

dividing the fuel cell electrode into an anode and a cathode.

6. The method of claim 1 wherein:

the solution includes a second metal salt such that the second metal salt is reduced to metallic form and the second metal precipitates in or on the electrode support structure.

7. The method of claim 1 further comprising:

placing an electrically conductive contact in the electrode support structure before dehydrating the electrode support structure.

8. The method of claim 1 wherein:

the reduction of the metal salt to metallic form is carried out by reducing ends of cellulose chains of the bacterial cellulose.