EP0051435A1
Expired / Lapsed
EP
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Three-layer laminated matrix electrode
Assignee: Eltech Systems Corp
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Filing: 1981-10-28
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Granted: —
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Expires: 2001-10-28
Abstract
Abstract The present disclosure is directed to an improved fibrillated, matrix-type active layer; laminated electrodes containing it which possess improved strength and durability and are capable of operation at high current density with enhanced resistance to mechanical failure, a process for producing such improved active layers and laminates. The process for producing these electrode active layers is characterized by alternately or simultaneously producing two components; combining the components; shear blending (fibrillating) the mixture; drying; chopping to a fine powder form, and rolling into a self-sustaining, coherent sheet form. Alternatively, the active layer can be formed by wet deposition of the powder on a filter paper or like medium. The term "matrix" as used herein means that the active carbon particles are present within an unsintered network of carbon blacklPTFE (fibrillated) material. This three-layer laminated electrode includes a porous, coherent, hydrophobic polytetrafluoroethylene (PTFE)-containing backing (wetproofing) layer, with or without carbon black therein, in contact with the nonworking surface of a "matrix" active layer containing catalyzed or uncatalyzed active carbon particles present within an unsintered network of fibrillated carbon black-PTFE and an electroconductive current distributor laminated to the working surface of said active layer, and to a process for making said laminate.
Inventors
- 👤 Frank Solomon
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-02 21:00
CPC Classifications
C; C25; C25B; C25B11/00
Claims Analysis
Total Claims: 46
Claim 1
Independent Claim
26 words
An electrode active layer comprising active carbon particles, characterized in that the carbon particles are present within an unsintered network or matrix of fibrillated carbon black/polytetrafluoroethylene.
Claim 2
Dependent Claim
26 words
An electrode active layer comprising active carbon particles, characterized in that the carbon particles are present within an unsintered network or matrix of fibrillated carbon black/polytetrafluoroethylene.
Claim 3
Dependent Claim
15 words
An active layer as claimed in claim 1, wherein the active carbon particles contain silver.
Claim 4
Dependent Claim
17 words
An active layer as claimed in claim 1 or 2, wherein the active carbon particles contain platinum.
Claim 5
Dependent Claim
26 words
An active layer as claimed in claim 1, 2 or 3, wherein the active carbon particles range in size from about 1 to about 30 microns.
Claim 6
Dependent Claim
28 words
An active layer as claimed in any of claims 1 to 4, wherein the carbon black comprises particles which range in size from about 50 to 3000 angstroms.
Claim 7
Dependent Claim
27 words
An active layer as claimed in claim 5, wherein the carbon black particles have a surface area ranging from about 25 to about 300 m 2 /g.
Claim 8
Dependent Claim
18 words
An active layer as claimed in any of claims 1 to 6, which contains a pore-forming bulking agent.
Claim 9
Dependent Claim
36 words
An active layer as claimed in any of claims 1 to 7, wherein the unsintered network contains by weight about 25 to about 35 parts of polytetrafluoroethylene and about 75 to 65 parts of carbon black.
Claim 10
Dependent Claim
36 words
An active layer as claimed in any of claims 1 to 8, wherein the concentration of active carbon ranges from about 40 to about 80 weight %; based on the total weight of the active layer.
Claim 11
Independent Claim
75 words
A method of preparing a matrix active layer comprising active carbon particles, for an electrode, characterized in that carbon black particles are intimately mixed with an aqueous dispersion of polytetrafluoroethylene particles, the resultant PTFE carbon black particulate component is mixed with active carbon particles to form an intimate mixture, the mixture is fibrillated and then formed into an active layer containing active carbon particles present within an unsintered network or matrix of fibrillated carbon black/polytetrafluoroethylene.
Claim 12
Independent Claim
75 words
A method of preparing a matrix active layer comprising active carbon particles, for an electrode, characterized in that carbon black particles are intimately mixed with an aqueous dispersion of polytetrafluoroethylene particles, the resultant PTFE carbon black particulate component is mixed with active carbon particles to form an intimate mixture, the mixture is fibrillated and then formed into an active layer containing active carbon particles present within an unsintered network or matrix of fibrillated carbon black/polytetrafluoroethylene.
Claim 13
Dependent Claim
38 words
A method as claimed in claim 10, wherein the carbon black particles have a particle size ranging from about 50 to about 3000 angstroms and a surface area ranging from about 25 to about 300 m 2 /g.
Claim 14
Dependent Claim
17 words
A method as claimed in claim 10 or 11, wherein the carbon black is an acetylene black.
Claim 15
Dependent Claim
17 words
A method as claimed in claim 10, 11 or 12, wherein the active carbon particles contain silver.
Claim 16
Dependent Claim
18 words
A method as claimed in claim 10, 11, 12 or 13, wherein the active carbon particles contain platinum.
Claim 17
Independent Claim
26 words
A method as claimed in any of claims 10 to 14, wherein the active carbon particles range in size from about 1 to about 30 microns.
Claim 18
Independent Claim
33 words
A method as claimed in any of claims 10 to 15, wherein the PTFE/carbon black component is heated at a. temperature of about 250° to about 325°C before being combined with active carbon.
Claim 19
Independent Claim
52 words
A method as claimed in any of claims 10 to 16, wherein the PTFE/carbon black component contains from about 65 to about 75 weight parts of carbon black and from about 35 to about 25 weight parts of polytetrafluoroethylene per 100 total weight parts of carbon black and polytetrafluoroethylene in the component.
Claim 20
Independent Claim
29 words
A method as claimed in any of claims 10 to 17, wherein the total mix contains from about 25 to about 50 weight % of a pore-forming bulking agent.
Claim 21
Dependent Claim
58 words
A laminated electrode including an active layer comprising active carbon particles, characterized in that the active carbon particles are present within an unsintered network or matrix of fibrillated carbon black/ polytetrafluoroethylene and the active layer is laminated on its working surface to a current distibutor and on its opposite surface to a porous coherent hydrophobic polytetrafluoroethylene-containing wet-proofing layer.
Claim 22
Dependent Claim
58 words
A laminated electrode including an active layer comprising active carbon particles, characterized in that the active carbon particles are present within an unsintered network or matrix of fibrillated carbon black/ polytetrafluoroethylene and the active layer is laminated on its working surface to a current distibutor and on its opposite surface to a porous coherent hydrophobic polytetrafluoroethylene-containing wet-proofing layer.
Claim 23
Dependent Claim
17 words
An electrode as claimed in claim 19, wherein the active carbon particles contain a precious metal catalyst.
Claim 24
Dependent Claim
14 words
An electrode as claimed in claim 20, wherein the precious metal catalyst is silver.
Claim 25
Dependent Claim
16 words
An electrode as claimed in claim 20 or 21, wherein the precious metal catalyst is platinum.
Claim 26
Dependent Claim
26 words
An electrode as claimed in any of claims 19 to 22, wherein the active carbon particles range in size from about 1 to about 30 microns.
Claim 27
Dependent Claim
35 words
An electrode as claimed in any of claims 19 to 23 wherein the-unsintered network contains.from about 25 to about 35 weight parts of polytetrafluoroethylene and about 75 to about 65 weight parts of carbon black.
Claim 28
Dependent Claim
20 words
An electrode as claimed in any of claims 19 to 24, wherein the active layer contains a pore-forming bulking agent.
Claim 29
Dependent Claim
26 words
An electrode as claimed in any of claims 19 to 25, wherein the carbon black particles range in size from about 50 to about 3000 angstroms.
Claim 30
Dependent Claim
30 words
An electrode as claimed in any of claims 19 to 26 wherein the carbon black particles have a surface area ranging from about 25 to about 300 m 2 /g.
Claim 31
Dependent Claim
35 words
An electrode as claimed in any of claims 19 to 27, wherein the concentration of active carbon ranges from about 40 to about 80 weight %, based on the total weight of the active layer.
Claim 32
Dependent Claim
76 words
A laminated oxygen cathode, characterized by having an active layer comprising active carbon particles having less than about 4 weight % ash, a B.E.T. surface area of about 500 m 2 /g or higher and a particle size of about 1 to 30 microns present within an unsintered network or matrix of fibrillated carbon black-polytetrafluoroethylene laminated on its working surface to a current distributor and-on its opposite surface to a porous coherent hydrophobic polytetrafluoroethylene-containing wetproofing layer.
Claim 33
Dependent Claim
76 words
A laminated oxygen cathode, characterized by having an active layer comprising active carbon particles having less than about 4 weight % ash, a B.E.T. surface area of about 500 m 2 /g or higher and a particle size of about 1 to 30 microns present within an unsintered network or matrix of fibrillated carbon black-polytetrafluoroethylene laminated on its working surface to a current distributor and-on its opposite surface to a porous coherent hydrophobic polytetrafluoroethylene-containing wetproofing layer.
Claim 34
Dependent Claim
18 words
An oxygen cathode as claimed in claim 29, wherein the active carbon particles contain a precious metal catalyst.
Claim 35
Dependent Claim
15 words
An oxygen cathode as claimed in claim 30, wherein the precious metal catalyst is platinum.
Claim 36
Dependent Claim
17 words
An oxygen cathode as claimed in claim 30 or 31, wherein the precious metal catalyst is silver.
Claim 37
Independent Claim
85 words
A method of preparing a laminated electrode comprising carbon black, characterized in that carbon black particles are intimately mixed with an aqueous dispersion of polytetrafluoroethylene particles the resultant intimate mixture is combined with active carbon particles to form a matrixing mixture, the latter mixture is fibrillated and formed into an active layer containing carbon particles and the working surface of the active layer is laminated to a current distributor on one surface and, on the opposite surface, to a porous coherent hydrophobic polytetrafluoroethylene-containing wetproofing layer.
Claim 38
Independent Claim
85 words
A method of preparing a laminated electrode comprising carbon black, characterized in that carbon black particles are intimately mixed with an aqueous dispersion of polytetrafluoroethylene particles the resultant intimate mixture is combined with active carbon particles to form a matrixing mixture, the latter mixture is fibrillated and formed into an active layer containing carbon particles and the working surface of the active layer is laminated to a current distributor on one surface and, on the opposite surface, to a porous coherent hydrophobic polytetrafluoroethylene-containing wetproofing layer.
Claim 39
Dependent Claim
39 words
A method as claimed in claim 33, wherein the carbon black particles have a particle size ranging from about 50 to about 3000 angstroms and a surface area ranging from about 25 to about 300 square meters per gram.
Claim 40
Dependent Claim
15 words
A method as claimed in claim 34, wherein the carbon black is an acetylene black.
Claim 41
Independent Claim
18 words
A method as claimed in any of claims 33 to 35, wherein the active carbon particles contain silver.
Claim 42
Independent Claim
18 words
A method as claimed in any of claims 33 to 36, wherein the active carbon particles contain platinum.
Claim 43
Independent Claim
26 words
A method as claimed in any of claims 33 to 37, wherein the active carbon particles range in size from about 1 to about 30 microns.
Claim 44
Independent Claim
35 words
A method as claimed in any of claims 33 to 38, wherein the PTFE/carbon black component is heat treated at a temperature of about 250° to 325 0 C before being combined with active carbon.
Claim 45
Independent Claim
52 words
A method as claimed in any of claims 33 to 39, wherein the PTFE/carbon black component contains from about 65 to about 75 weight parts of carbon black and from about 35 to about 25 weight parts of polytetrafluoroethylene per 100 total weight parts of carbon black and polytetrafluoroethylene in the component.
Claim 46
Independent Claim
29 words
A method as claimed in any of claims 33 to 40, wherein the total mix contains from about 25 to about 50 weight % of a pore-forming bulking agent.
References Cited (Backward Citations)
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