US4925746A
Expired / Lapsed
US
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Device for recombing hydrogen and oxygen released in lead-acid storage batteries
Assignee: Zentralna Laboratoria Po Electrochimicheski Iztochnici Na Tok
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Filing: 1988-04-20
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Granted: 1990-05-15
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Expires: 2008-04-20
Abstract
Abstract A device for recombining hydrogen and oxygen released in maintenance-free ad-acid storage batteries as well as their electrochemical conversion is composed of electrodes employed in a stack enveloped in a sheath of microporous material with the individual electrodes also being separated by such material. The device may be employed in sealed storage batteries when connected through a diode to the negative pole of a cell of the battery. A stack of electrodes may be divided in two parts, one part connected through a diode to the negative pole and the other part connected through a diode and a resistor to the positive pole, at which time the device is immersed partially in the electrolyte of the cell. The electrodes contains a catalyst from a combination of tungsten carbide and the active or activate carbon and a polymeric binder on a support grid of lead or lead alloy, the catalyst/binder mixture having been pressed onto the support grid or forming two layers situated at the surfaces of the electrode. Between these two catalytic layers a third layer composed of carbon black and binder, and containing the support grid, is situated.
Inventors
- 👤 Dechko Pavlov
- 👤 Todor V. Donchev
- 👤 Ivan P. Nikolov
- 👤 Veneta I. Nikolova
- 👤 Geno P. Papazov
- 👤 Konstantin M. Petrov
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:19
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/52; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
223 words
A device for rendering a lead-acid storage battery maintenance-free and suitable for sealing by recombining and electrochemically converting hydrogen and oxygen released in each battery cell having a positive and a negative pole, said device comprising an electrode stack of catalytically active electrodes enveloped in a microporous sheath; said electrodes each comprising a catalyst selected from the group consisting of tungsten carbide, a mixture of tungsten carbide and active carbon, and a mixture of tungsten carbide and activated carbon; said electrodes each further comprising a binder and a mixture of catalyst and binder being pressed onto a support grid; said support grid comprising an element selected from the group consisting of lead and lead alloy; each electrode being separated from an adjacent electrode in said stack by a microporous sheet material; said electrode stack being divided in two parts, one part being connected by means of a diode to the negative pole and the other part being connected by means of a diode and a resistor to the positive pole; said electrode stack being partially immersed in electrolyte; the potential of the part of the stack connected to the negative pole being kept between 0.3 and 0.5 V and the potential of the part of the stack connected to the positive pole being kept between 0.1 and 0.3 V versus a hydrogen electrode.
Claim 2
Independent Claim
223 words
A device for rendering a lead-acid storage battery maintenance-free and suitable for sealing by recombining and electrochemically converting hydrogen and oxygen released in each battery cell having a positive and a negative pole, said device comprising an electrode stack of catalytically active electrodes enveloped in a microporous sheath; said electrodes each comprising a catalyst selected from the group consisting of tungsten carbide, a mixture of tungsten carbide and active carbon, and a mixture of tungsten carbide and activated carbon; said electrodes each further comprising a binder and a mixture of catalyst and binder being pressed onto a support grid; said support grid comprising an element selected from the group consisting of lead and lead alloy; each electrode being separated from an adjacent electrode in said stack by a microporous sheet material; said electrode stack being divided in two parts, one part being connected by means of a diode to the negative pole and the other part being connected by means of a diode and a resistor to the positive pole; said electrode stack being partially immersed in electrolyte; the potential of the part of the stack connected to the negative pole being kept between 0.3 and 0.5 V and the potential of the part of the stack connected to the positive pole being kept between 0.1 and 0.3 V versus a hydrogen electrode.
Claim 3
Independent Claim
178 words
A device for rendering a lead-acid storage battery maintenance-free and suitable for sealing by recombining and electrochemically converting hydrogen and oxygen released in each battery cell having a positive and a negative pole, said device comprising an electrode stack of catalytically active electrodes enveloped in a microporous sheath; said electrodes each comprising a catalyst selected from the group consisting of tungsten carbide, a mixture of tungsten carbide and active carbon, and a mixture of tungsten carbide and activated carbon; said electrodes each further comprising a binder and a mixture of catalyst and binder being pressed onto a support grid; said support grid comprising an element selected from the group consisting of lead and lead alloy; each electrode being separated from an adjacent electrode in said stack by a microporous sheet material; said electrodes in said stack being connected to one another; said electrode stack being connected by means of a diode to the negative pole; said electrode stack being partially immersed in electrolyte; the potential of the device being kept at 0.3 ±0.2 V versus a hydrogen electrode.
Claim 4
Independent Claim
178 words
A device for rendering a lead-acid storage battery maintenance-free and suitable for sealing by recombining and electrochemically converting hydrogen and oxygen released in each battery cell having a positive and a negative pole, said device comprising an electrode stack of catalytically active electrodes enveloped in a microporous sheath; said electrodes each comprising a catalyst selected from the group consisting of tungsten carbide, a mixture of tungsten carbide and active carbon, and a mixture of tungsten carbide and activated carbon; said electrodes each further comprising a binder and a mixture of catalyst and binder being pressed onto a support grid; said support grid comprising an element selected from the group consisting of lead and lead alloy; each electrode being separated from an adjacent electrode in said stack by a microporous sheet material; said electrodes in said stack being connected to one another; said electrode stack being connected by means of a diode to the negative pole; said electrode stack being partially immersed in electrolyte; the potential of the device being kept at 0.3 ±0.2 V versus a hydrogen electrode.
Claim 5
Dependent Claim
49 words
A device as claimed in claim 1 or 2 wherein the catalytically active electrode comprises carbon activated by an element selected from the group consisting of a metal-chelate compound and its product of thermal treatment in a non-oxygen containing medium at a temperature of from 300° to 1000° C.
Claim 6
Dependent Claim
21 words
A device as claimed in claim 3, wherein the metal-chelate compound is selected from the group consisting of annulene and porphyrin.
Claim 7
Dependent Claim
24 words
A device as claimed in claim 3, wherein the metal-chelate compound has been applied in an amount up to 20% by weight of carbon.
Claim 8
Dependent Claim
27 words
A device as claimed in claim 1 or 2, wherein the binder comprises an element selected from the group consisting of polytetrafluorethylene, polytrifluorethylene, polyethylene, polyisobutylene, and polypropylene.
Claim 9
Dependent Claim
26 words
A device as claimed in claim 1 or 2, wherein the binder comprises an element selected from the group consisting of carbon black and activated carbon.
Claim 10
Dependent Claim
22 words
A device as claimed in claim 1 or 2, wherein the binder constitutes from 5 to 60% by weight of said mixture.
Claim 11
Dependent Claim
45 words
A device as claimed in claim 1 or 2, wherein the catalyst and binder are homogeneously distributed in the electrode, the catalyst/binder mixture being pressed onto the grid at preferably 50° to 400° C. in the amount of from 0.01 to 1 g/cm 2 .
Claim 12
Dependent Claim
77 words
A device as claimed in claim 9, wherein the catalyst/binder mixture is distributed in two layers in amount from 0.01 to 1.0 g catalyst/cm 2 ; the two layers are situated at the two electrode surfaces; and a third layer is disposed between the two layers, said third layer comprising 5 to 60% carbon black and polymeric binder, this three-layer electrode being formed by pressing the three layers at a temperature preferably from 50° to 400° C.
Claim 13
Dependent Claim
30 words
A device as claimed in claim 1 or 2, wherein the microporous sheath is formed of an element selected from the group consisting of polyvinylchloride, polyethylene, polypropylene and latex-formaldehyde resin.
References Cited (Backward Citations)
US3790410A
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JPS4925574A
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JPS4933817A
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US4172808A
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JPS5415140A
Cited
US4810598A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-05-14 | 1993-11-13 | 1994-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-05-14 | 1997-11-13 | 1998-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-05-14 | 2001-11-13 | 2002-05-15 | $7700.00 | Window Closed / Lapsed |