Three layer laminate

• US 4,456,521 A
• Filed: 04/19/1983
• Issued: 06/26/1984
• Est. Priority Date: 10/31/1980
• Status: Expired due to Fees

• Current Assignee: Eltech Systems Corporation (Industrie De Nora S.p.A)
• Original Assignee: Diamond Shamrock Corp (Valero Energy Corporation)
• Inventors: Solomon, Frank, Grun, Charles
• Primary Examiner(s): Niebling, John F.
• Application Number:
  US06/486,468
• Time in Patent Office: 434 Days
• Field of Search: 429/42, 204/292, 204/294
• US Class Current: 204/292
• CPC Class Codes: C25B 11/04 characterised by the material
• CPC Class Codes: C25B 11/043 Carbon, e.g. diamond or graphene
• CPC Class Codes: H01M 4/8821 Wet proofing
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: H01M 4/926 on carbon or graphite
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The disclosure is directed to preparing three-layer laminated electrodes suitable for use as oxygen (air) cathodes in chlor-alkali and other electrochemical cells, fuel cells and in other electrochemical applications.

This three-layer laminate includes an active layer or sheet containing from about 60 to about 85 wt. % active carbon, the remainder being unsintered, fibrillated polytetrafluoroethylene in intimate admixture with said active carbon, said active layer laminated on its working surface to a current distributor and on its opposite surface to a porous, coherent, hydrophobic polytetrafluoroethylene-containing wetproofing layer.

Claims

1. In a laminated oxygen cathode comprising an active layer or sheet laminated on its working surface to a current distributor and on its opposite surface to a polytetrafluoroethylene-containing wetproofing layer, the improvement comprising said active layer or sheet being formed from a fibrillated mixture of unsintered polytetrafluoroethylene and active carbon particles surface area of at least about 1000 m² /g or more and a particle size of about 1 to about 30 microns.

2. An oxygen cathode as in claim 1 wherein said active carbon contains a precious metal catalyst.

3. An oxygen cathode as in claim 2 wherein said precious metal is platinum.