US4585711A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrogen electrode for a fuel cell
Assignee: Comsat Corp
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Filing: 1983-12-15
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Granted: 1986-04-29
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Expires: 2003-12-15
Abstract
Abstract A hydrogen electrode and the method of making the electrodes usable in a fuel cell comprising a perforated nickel foil current collector, the back side of which is sealed with a semi-permeable membrane of polytetrafluoroethylene (PTFE) with a thickness of 50 μm and a pore diameter of 0.2 μm. The front side is sealed with an electrocatalytic layer of about 25 μm thickness. The electrocatalytic layer contains 75%, by weight, catalyst (carbon particles coated with a layer of catalyzing platinum) with a platinum loading of 0.25-0.6 mg/cm 2 . The platinum-covered carbon black is dispersed and embedded as individual but touching granules in strands of PTFE composing 25% of the layer. The porosity of the layer is 80% with a mean volume pore diameter of 10 μm. The strands are obtained by roll compaction of granular PTFE.
Inventors
- 👤 Hariharan Vaidyanathan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:24
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108; Y10T29/49115
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
64 words
An electrode, comprising: a perforated conductive foil for collecting current; a semi-permeable layer of polytetrafluoroethylene (PTFE) bonded to one side of said foil for wet-proofing said one side and having an average volume pore diameter of 0.1-0.3 μm; and an electrocatalytic layer bonded to the other side of said foil comprising granules of carbon coated with platinum dispersed in a matrix of filamentary PTFE.
Claim 2
Dependent Claim
64 words
An electrode, comprising: a perforated conductive foil for collecting current; a semi-permeable layer of polytetrafluoroethylene (PTFE) bonded to one side of said foil for wet-proofing said one side and having an average volume pore diameter of 0.1-0.3 μm; and an electrocatalytic layer bonded to the other side of said foil comprising granules of carbon coated with platinum dispersed in a matrix of filamentary PTFE.
Claim 3
Dependent Claim
12 words
An electrode as recited in claim 1, wherein said foil comprises nickel.
Claim 4
Dependent Claim
16 words
An electrode as recited in claim 2, wherein said nickel foil is an extruded nickel foil.
Claim 5
Dependent Claim
17 words
An electrode as recited in claim 1, wherein said semi-permeable layer having a thickness of 25-75 μm.
Claim 6
Dependent Claim
27 words
An electrode as recited in claim 1, wherein said electrocatalytic layer having a thickness of 12-40 μm and a medium volume pore diameter of about 10-15 μm.
Claim 7
Dependent Claim
32 words
An electrode as recited in claim 1, wherein the weight ratio of platinum-coated carbon to PTFE is between 67:33 and 77:23 and the loading of platinum is about 0.25-0.6 mg/cm 2 .
Claim 8
Dependent Claim
43 words
An electrode as recited in claim 6, wherein: said foil is an extruded nickel foil; said semi-permeable layer has a thickness of 15-75 μm; and said electrocatalytic layer has a thickness of 12-40 m and a medium volume pore diameter of 10-15 μm.
Claim 9
Dependent Claim
110 words
A process for fabricating an electrode, comprising the steps of: blending a mixture of granular polytetrafluoroethylene (PTFE), granular carbon coated with platinum, a bulking agent and a lubricant; rolling said blended mixture to a thin layer; drying said layer for removing said bulking agent and lubricant, and for reducing the thickness of said layer; bonding said dried layer to one side of a conductive grid, said grid acting as a current collector and said bonded dried layer acting as an electrocatalytic layer; bonding a microporous layer of PTFE to the other side of said conductive grid, said microporous layer acting as a wet-proofing layer; and sintering said bonded dried layer.
Claim 10
Dependent Claim
110 words
A process for fabricating an electrode, comprising the steps of: blending a mixture of granular polytetrafluoroethylene (PTFE), granular carbon coated with platinum, a bulking agent and a lubricant; rolling said blended mixture to a thin layer; drying said layer for removing said bulking agent and lubricant, and for reducing the thickness of said layer; bonding said dried layer to one side of a conductive grid, said grid acting as a current collector and said bonded dried layer acting as an electrocatalytic layer; bonding a microporous layer of PTFE to the other side of said conductive grid, said microporous layer acting as a wet-proofing layer; and sintering said bonded dried layer.
Claim 11
Dependent Claim
34 words
A process as recited in claim 8, wherein: the granular PTFE has an average diameter of 250-750 μm; and said mixture has a weight ratio of platinum-coated carbon to PTFE between 67:33 and 77:23.
Claim 12
Dependent Claim
21 words
A process as recited in claim 9, wherein the weight ratio of the platinum to carbon is between 1:9 and 1:19.
Claim 13
Dependent Claim
43 words
A process as recited in claim 10, wherein two said bonding steps comprise the steps of: laminating said dried layer on said one side of said grid; laminating said microporous layer on said other side of said grid; and pressing said laminated grid.
Claim 14
Dependent Claim
17 words
A process as recited in claim 11, wherein said conductive grid is an extruded foil of nickel.
Claim 15
Dependent Claim
43 words
A process as recited in claim 9, wherein two said bonding steps comprise the steps of: laminating said dried layer on said one side of said grid; laminating said microporous layer on said other side of said grid; and pressing said laminated grid.
Claim 16
Dependent Claim
17 words
A process as recited in claim 9, wherein said conductive grid is an extruded foil of nickel.
Claim 17
Dependent Claim
21 words
A process as recited in claim 8, wherein the weight ratio of the platinum to carbon is between 1:9 and 1:19.
Claim 18
Dependent Claim
28 words
A process as recited in claim 8 wherein said sintering step comprises heating for approximately ten minutes at a temperature of substantially 330° C. in a nitrogen environment.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1989-04-28 | 1989-10-28 | 1990-04-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-04-28 | 1993-10-28 | 1994-04-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-04-28 | 1997-10-28 | 1998-04-29 | $7700.00 | Window Closed / Lapsed |