EP0051440A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Chlor-alkali cell with non-bleeding 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 This disclosure is directed to a non-bleeding gas electrode for operation under the rigors of high current density and to the active layer thereof. This active layer is comprised of 60 to 90 weight percent high surface area, electroconductive carbon (with or without catalyst thereon), 10 to 40 weight percent particulate polytetrafluoroethylene (PTFE) and has pores sufficiently large to relieve internal hydrodynamic pressures thus preventing liquid being forced through the electrode wetproofing layer to the air side thereof. In addition such electrodes include a PTFE-containing wetproofing or backing layer secured on one side to said active layer and on the other side to a current distributor. The pores in both the active layer and the backing layer are controlled to relieve hydrodynamic pressures by coordinating the particle size of the pore former used to establish the pores in both said layers such that the repellancy of the backing layer to hot alkali exceeds the internal liquid pressures in the active layer Of particular significance is the fact that the present electrode is non-bleeding when operated on air and preserves its low voltage at high current density over extended time periods without bleeding.
Inventors
- 👤 Frank Solomon
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 22:50
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; H01M4/8878; H01M4/8882; H01M4/8885; C; C25; C25B; C25B11/00; C25B11/04; H01M4/96; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y10; Y10T; Y10T428/00; Y10T428/31504; Y10T428/3154
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
40 words
A.-non-bleeding gas electrode, characterized by a hydrophobic polytetrafluoroethylene-containing porous backing layer, an active layer containing high surface area carbon particles and a current distributor, the active layer having pores sufficiently large to relieve internal liquid pressure in the active layer.
Claim 2
Dependent Claim
40 words
A.-non-bleeding gas electrode, characterized by a hydrophobic polytetrafluoroethylene-containing porous backing layer, an active layer containing high surface area carbon particles and a current distributor, the active layer having pores sufficiently large to relieve internal liquid pressure in the active layer.
Claim 3
Dependent Claim
16 words
An electrode as claimed in claim 1, wherein the carbon particles contain a precious metal catalyst.
Claim 4
Dependent Claim
17 words
An electrode as claimed in claim 1 or 2, wherein the carbon particles are active carbon particles.
Claim 5
Dependent Claim
17 words
An electrode as claimed in claim 1 or 2, wherein the carbon particles are carbon black particles.
Claim 6
Dependent Claim
17 words
An electrode as claimed in any of claims 1 to 4, wherein the active layer contains polytetrafluoroethylene.
Claim 7
Dependent Claim
14 words
An electrode as claimed in any of claims 1 to 5, which is sintered.
Claim 8
Dependent Claim
32 words
An electrode as claimed in any of claims 1 to 6, wherein.the average size of the pores in the active layer is in the range from about 1 to about 40 microns.
Claim 9
Dependent Claim
33 words
An electrode as claimed in any of claims 1 to 7, wherein the average size of the pores in the backing layer is in the range from about 1 to about 40 microns.
Claim 10
Dependent Claim
34 words
An electrode as claimed in any of claims 1 to 8, wherein the average size of the active layer pores is at least as large as the average size of the backing layer pores.
Claim 11
Dependent Claim
27 words
An electrode as claimed in claim 9, wherein the average size of the active layer pores is larger than the average size of the backing layer pores.
Claim 12
Dependent Claim
25 words
An electrode as claimed in any of claims 1 to 10, wherein the active layer is located between the backing layer and the current distributor.
Claim 13
Dependent Claim
81 words
. 12. An electrode precursor, . characterized by comprising a hydrophobic backing layer containing polytetrafluoroethylene and a pore former, an active layer containing high surface area carbon particles and a pore former and a current distributor, wherein the average particle size of the active layer pore former is in the range from about 1 to about 40 microns and is sufficiently large to relieve internal liquid pressure generated in the active layer during use thereof after removal of the pore formers.
Claim 14
Dependent Claim
81 words
. 12. An electrode precursor, . characterized by comprising a hydrophobic backing layer containing polytetrafluoroethylene and a pore former, an active layer containing high surface area carbon particles and a pore former and a current distributor, wherein the average particle size of the active layer pore former is in the range from about 1 to about 40 microns and is sufficiently large to relieve internal liquid pressure generated in the active layer during use thereof after removal of the pore formers.
Claim 15
Dependent Claim
21 words
An electrode precursor as claimed in claim 12, wherein the active and backing layer pore formers comprise a soluble pore former.
Claim 16
Dependent Claim
15 words
An electrode as claimed in claim 13, wherein the soluble pore former is sodium carbonate.
Claim 17
Dependent Claim
21 words
An electrode precursor as claimed in claim 12, wherein the active and backing layer pore formers comprise a volatile pore former.
Claim 18
Dependent Claim
16 words
An electrode precursor as claimed in claim 15, wherein the volatile pore former is ammonium benzoate.
Claim 19
Dependent Claim
21 words
An electrode precursor as claimed in any of claims 12 to 16, wherein the high surface area carbon is carbon black.
Claim 20
Dependent Claim
21 words
An electrode precursor as claimed in any of claims 12 to 16, wherein the high surface area carbon is active carbon.
Claim 21
Dependent Claim
23 words
An electrode precursor as claimed in any of claims 12 to 18, wherein the high surface area carbon contains a precious metal catalyst.
Claim 22
Dependent Claim
19 words
An electrode precursor as claimed in any of claims 12 to 19, wherein the active layer additionally contains polytetrafluoroethylene,
Claim 23
Dependent Claim
15 words
An electrode precursor as claimed in any of claims 12 to 20, which is sintered.
Claim 24
Dependent Claim
26 words
An electrode precursor as claimed in any pf claims 12 to 21, wherein the active layer is located between the backing layer and the current distributor.
Claim 25
Independent Claim
97 words
A method of making a non-bleeding electrode, characterized in that a backing layer containing polytetrafluoroethylene and a pore former is prepared and assembled with an active layer and a current distributor, the resulting assembly is consolidated and the active and backing layer pore formers is/are removed, wherein the active layer contains high surface area carbon particles and a pore former, the average particle size of the active layer pore former being in the range from about 1 to about 40 microns and being sufficiently large to relieve internal liquid pressure generated in the active layer during use.
Claim 26
Independent Claim
97 words
A method of making a non-bleeding electrode, characterized in that a backing layer containing polytetrafluoroethylene and a pore former is prepared and assembled with an active layer and a current distributor, the resulting assembly is consolidated and the active and backing layer pore formers is/are removed, wherein the active layer contains high surface area carbon particles and a pore former, the average particle size of the active layer pore former being in the range from about 1 to about 40 microns and being sufficiently large to relieve internal liquid pressure generated in the active layer during use.
Claim 27
Dependent Claim
21 words
A method as claimed in claim 23, wherein the active layer is assembled between the backing layer and the current distributor.
Claim 28
Dependent Claim
29 words
A method as claimed in claim 23 or 24, wherein the average size of the backing layer pores is in the range from about 1 to about 40 microns.
Claim 29
Dependent Claim
30 words
A method as claimed in claim 25, wherein the average size of the active layer pores is at least as large as the average size of the backing layer pores.
Claim 30
Dependent Claim
27 words
A method as claimed in claim 26, wherein the average size of the active layer pores is larger than the average size of the backing layer pores.
Claim 31
Independent Claim
21 words
A method as claimed in any of claims 23 to 27, wherein the active and backing layer pore formers is/are soluble.
Claim 32
Dependent Claim
14 words
A method as claimed in claim 28, wherein the pore former is sodium carbonate.
Claim 33
Independent Claim
21 words
A method as claimed in any of claims 23 to 27, wherein the active and backing layer pore formers is/are volatile.
Claim 34
Dependent Claim
15 words
A method as claimed in claim 30, wherein the volatile pore former is ammonium benzoate.
Claim 35
Independent Claim
24 words
A method as claimed in any of claims 23 to 31, in which the consolidated assembly is sintered after removal of the pore former(s).
Claim 36
Independent Claim
18 words
A method as claimed in any of claims 23 to 32, wherein the active layer additionally contains polytetrafluoroethylene.
References Cited (Backward Citations)
GB2018501A
Cited
GB2025114A
Cited
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