CA1142220A - Cadium compound additive for cells using divalent silver oxide - Google Patents
Cadium compound additive for cells using divalent silver oxideInfo
- Publication number
- CA1142220A CA1142220A CA000387244A CA387244A CA1142220A CA 1142220 A CA1142220 A CA 1142220A CA 000387244 A CA000387244 A CA 000387244A CA 387244 A CA387244 A CA 387244A CA 1142220 A CA1142220 A CA 1142220A
- Authority
- CA
- Canada
- Prior art keywords
- silver oxide
- oxide
- cell
- electrolyte
- divalent silver
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Abstract
CADMIUM COMPOUND ADDITIVE FOR
CELLS USING DIVALENT SILVER
OXIDE ELECTRODES
ABSTRACT OF THE INVENTION
An alkaline silver oxide cell having a negative electrode, an alkaline electrolyte and a positive electrode comprising a major amount of divalent silver oxide and wherein a minor amount of a cadmium compound, such as cadmium oxide, Is incorporated into the electrolyte and/or positive electrode to improve the chemical stability of the divalent silver oxide in contact with the alkaline electrolyte.
S P E C I F I C A T I O N
1.
CELLS USING DIVALENT SILVER
OXIDE ELECTRODES
ABSTRACT OF THE INVENTION
An alkaline silver oxide cell having a negative electrode, an alkaline electrolyte and a positive electrode comprising a major amount of divalent silver oxide and wherein a minor amount of a cadmium compound, such as cadmium oxide, Is incorporated into the electrolyte and/or positive electrode to improve the chemical stability of the divalent silver oxide in contact with the alkaline electrolyte.
S P E C I F I C A T I O N
1.
Description
ll~Z~ZO
FIELD OF THE I~VENTION
The invention relates to a silver oxide alkaline cell employing a divalent silver oxide containing positive electrode and wherein a minor amount of a cadmiu~ compound, such as cadmium oxide, is incorporated into the positive electrode and/or the electrolyte so as to improve the chemical stability of the divalent silver oxide in contact with the alkaline electrolyte. In addition, the cadmium compound c n be em~loyed as an overbalance depolarizer in a divalent silver oxide/zinc/alkaline cell so as to substantially prevent hydrogen gassing from the cathode upon complete discharge of the cell~
BACKGROUND OF THE I~VENTION
The battery has become a primary power source for many portable electronic devices such as radios, hearing aids, watches, calculators and the like. In order to maintain the overall electronic device as compact as possible the electronic devices are u~ually designed with cavities to accommodate~iniature cells as their source of power. The ca~ities are usually made so that a cell can be snugly positionet therein thus making electronic contact with appropriate terminals within the device. A major potential problem in the use of a high energy density cell such as a divalent silver oxide/zinc/alkaline cell, is that if the cell bulges, it usually becomes wedged within the cavity of the device which sometimes can result in damage to the device. In addition, when the cell bulges it may disturb the seal wheseupon the electrolyte might escape to cause damage to the device andlor oxygen from the atmosphere may enter which could cause wasteful corrosion of the anode.
FIELD OF THE I~VENTION
The invention relates to a silver oxide alkaline cell employing a divalent silver oxide containing positive electrode and wherein a minor amount of a cadmiu~ compound, such as cadmium oxide, is incorporated into the positive electrode and/or the electrolyte so as to improve the chemical stability of the divalent silver oxide in contact with the alkaline electrolyte. In addition, the cadmium compound c n be em~loyed as an overbalance depolarizer in a divalent silver oxide/zinc/alkaline cell so as to substantially prevent hydrogen gassing from the cathode upon complete discharge of the cell~
BACKGROUND OF THE I~VENTION
The battery has become a primary power source for many portable electronic devices such as radios, hearing aids, watches, calculators and the like. In order to maintain the overall electronic device as compact as possible the electronic devices are u~ually designed with cavities to accommodate~iniature cells as their source of power. The ca~ities are usually made so that a cell can be snugly positionet therein thus making electronic contact with appropriate terminals within the device. A major potential problem in the use of a high energy density cell such as a divalent silver oxide/zinc/alkaline cell, is that if the cell bulges, it usually becomes wedged within the cavity of the device which sometimes can result in damage to the device. In addition, when the cell bulges it may disturb the seal wheseupon the electrolyte might escape to cause damage to the device andlor oxygen from the atmosphere may enter which could cause wasteful corrosion of the anode.
2.
1142fi 2n On the Dther hand, lf the ~eal of the cell is m2intained, high $nternal g~s pressure may develop which coult cause not only bulging of the cel} but even pos~ible disassembly of the cell.
Although divalent cilver oxide is a good hi8h ca?acity positive active material when used in alkaline cells, it is rather unstable when in contact wieh an aqueous alkaline elec-trolyte. Specifically, divalene 6ilver oxide is a highly oxi-dizing material nd as 6uch it i6 capable of decomposing the water in an aqueous al~aline electrolyte there~y yielding oxy-gen gas, In ddition, divalent ~ilver oxide will liberate oxy-gcn when lt decomposes to form monovalent ~ilver oxide when in contact with the queous alkaline electrolyte. Divalent silver oxide can also attack cellulosic materials in the cell, such as the separator, to form carbonate ion at the expense of even more electrolyte. These are undesirable processes because they lead to bulging of the cell, deterioration of its parts and loss of ~ervice.
U. S. Patent 3,853,623 discloses one approach to ~tabilize divalent ~ilver oxide in silver oxide/zinc/ alkaline cell through the use of gold ions incorporated inro the alkaline clec roly~e on the posi~ive ~ide of .he cell's separaror or gold oxide added ta the positive active material of ~he cell.
Canadian a~lication ~erial no. 323,519 discloses an alkaline ~ilver oxide cell employing divalent 6ilver oxide-containing electrode wherein an alu~-lnum additive i~ incorporated in the cell to improve the ~hemical ctability of the divalent silver oxide when in contact f~ ~0~
~."
'~ i 11426 ` ll~Z22C) with the cell's alkaline electrolyte.
It is an object of the present invention to provide a divalent silver oxide cell thAt will minimize internal gas pressure buildup so as to effectively eliminate distortion of the cell's housing.
It is another object of the present invention to provide a divalent silver oxide cell wherein a cadmium compound, such as cadmium oxide, is incorporated into the cell's electrolyte and/or the positive electrode so as to effectively control gas pressure builtup within the cell and thereby effectively eliminate distortion of the cell's housing.
It is another ob;ect of the present invention to incorporate a cadmium compound, such as cadmium oxide.in a divalent silver oxide cell to chemically stabilize the divalent silver oxide when in contact with the cell's aqueous electrolyte.
It is another object of the present invention to incorporate a cadmium compound, such as cadmium oxide, in a divalent silver oxide/zinc cell as an overbalance depolarizer to effectively prevent hydrogen gassing from the cathode upon complete discharge of the cell.
The foregoing and additional objects will become more fully apparent from th~ following description.
SUMMARY OF THE I~VENTION
The invention relates to a silver oxide cell having a negative electrode, An aqueous alkaline electrolyte, a positive electrode comprising a major portion of divalent -~ 11426 ~422;~:~
, silver oxide and a separator between said negative and positive electrodes,the im~rovement comprising the incorporation of a minor amount of a cadmium compound, such as ca~mium oxide, into the positi~e electrode and/or into the electrolyte of the cell to ~mprove the stability of the divalent silver oxide-containing electrode in contact with the aqueous alkaline electrolyte.
As used herein, a positive electrode or a silver electrode shall mean an electrode wherein the active cathode material is divalent silver oxide (AgO) or an electrode wherein the major active material is divalent silver oxide in conjunction with an amount below 50% by weight of novalent silver oxide CAg20) and/or some other electro-chemically active positive material.
The cadmium compound, such as cadmium oxide, may be added in the solid positive electrode andlor dissol~ed in the electrolyte. The ca~mium compound added to the positive electrode may be either admixed with the divalent silver oxide or incorporated within the divalent silver oxide crystallites themselves through coprecipitation or absorption dur$ng synthesis. Admixture of the cadmium compound and d$valent silver oxide material has the advantage of greater flexibility in the choice of the divalent silver oxide material with regard to particle size, purity and the like.
The minor amount of the cadmium compound additive for use in the positive electrode of this invention to improve the stability of the divalent silver oxide when ~ Z 2~ 11426 in contact with ~he cell's aqueous alkaline electrolyte should be between about 0.01 and about 5 per cent based on the dry weight of the divalent silver oxide in the positive electrode and prefèrably between about 0.1 and about 0.3 weight Per cent based on the try weight of the divalent silver oxide in the positive electrote. An amount of the cadmium compound less than, for example, about O.Olweight per cent, would not provide sufficient material to effectively improve the stability of the divalent silver oxide material when in contact with the aqueous alkaline electrolyte. An amount of the cadmium compound more than, for example, about 5 weight per cent added to the positive electrode would not further improve the stability of the divalent silver oxide when in contact with the aqueous alkaline electrolyte.
The cadmium compound to be added to the electrolyte in accordance with this invention should be added in an amount between about 0.0001 per cent and up to saturation of the csdmium compound in the electrolyte. For example, when using a 33 per cent potassium hydroxide solution, the upper limit would be about 0.00125 per cent based on the weight of the electroly~e. An amount of the cadmium oxide less than, for example, about 0.0001 per cent would not provide sufficient material to effectively improve the stability of the divalent silver oxide material when in contact with the aqueous alkaline electrolyte.
In addition to its use as a stabilizing agent, cadmium oxide may also be used in larger amounts ranging 6.
, ' ' ~ ','.:; ' . ' 1~4Z~:20 fr~m a~out 5 per cent to about 25 per cent by weight of the dry constituçnts of the positive electrode, as an overbalance depolarizer in a divalent silver oxide cell. An overbalance depolarizer is that part of the positive electrote in excess of the stoichiometric amount neeted to balance the negati~e electrode. Its purpose is to augment the positive electrode capacity sufficiently to prevent hydrogen gassing from the cathode upon complete discharge of the cell (anode-limited), Like divalent ~ilver oxide, a cadmium compound, such as cadmium oxide, has limited solubility in alkaline environments, discharges at a potential positive to hydrogen, and its volumetric energy density is sufficiently high so as not to impair the over-all energy density of the silver oxide/anode system. As an overbalance substitute for divalent silver oxide, its advantages are that it iæ far less costly and imparts chemical stability to the divalent silver oxide material when in contact with aqueous alkaline electrolyteO
It is al90 within the scope o~ this invention to additionally dd zinc oxide or aluminate ions to the elec-trolyte, and/or zinc oxide or aluminum oxide to the positiveelectrode. The zinc oxide and aluminate ions can be added to the electrolyte in a range between about 0.5 and about 5 per cent based on the weight of the electrolyte. When incorporatet in the positive electrode, the zinc oxide and aluminum oxide can be added in an amount between about 0.5 and about 5 and about 0.001 and about 0.1 weight per cent, respectively, baset on the dry weight of the divalent silver ll~ZZZC~
oxide in the positive electrode. Zinc oxide has been found to be more desirable than aluminum oxide. Unexpectedly, the combination of cadmium oxide in the positive electrode and zinc oxide or aluminate ions in the electrolyte produced a synergistic effect on the stability of divalent silver oxite in contact with the a~ueous alkaline electrolyte.
It is also within the scope of this invention tO
additionally add a minor amount of a stabilizer, a flow agent ant/or a lubricat~ng agent to the active positive mix to further alter the physical characteristics of the active po~itive mix for molding purposes to produce various size and type electrodes. Examples of some of these additives are ethylene bis-stearamide, ~inc stearate, lead stearate, calcium 8tearate and the like.
The silver oxide electrodes of this in~ention may , be employet in an aqueous cell system using an anode such as zinc, cadmium, in~ium or the li~e. The electrode couple so selectet can be employed with a compatible electrolyte and preferably an alkaline electrolyte. Examples of sultable electrolytes include aqueous solutions of alkaline earth metal hytroxides, 8uch as strontium hydroxide and alkali metal hytroxides, exemplified by sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide and cesium hydroxide. Com~atible mixtures of the preceding may be utilized. Preferably, the electrode of this invention should be porous so that the walls of the pores and interstices of the electrode can become wetted by the electrolyte.
EXAMPLE I
Several lots of test cells were produced each using a divalent silver oxide-containing posieive pellet having a density of 90 grams per cubic inch, a negative electrode of zinc, and a 33z KOH electrolyte. The positive electrode was positioned in a cathote collector cup with a zinc screen disposet between ehe inner surface of the cup and the positive pellet as disclosed in U. S. Patent No.
1142fi 2n On the Dther hand, lf the ~eal of the cell is m2intained, high $nternal g~s pressure may develop which coult cause not only bulging of the cel} but even pos~ible disassembly of the cell.
Although divalent cilver oxide is a good hi8h ca?acity positive active material when used in alkaline cells, it is rather unstable when in contact wieh an aqueous alkaline elec-trolyte. Specifically, divalene 6ilver oxide is a highly oxi-dizing material nd as 6uch it i6 capable of decomposing the water in an aqueous al~aline electrolyte there~y yielding oxy-gen gas, In ddition, divalent ~ilver oxide will liberate oxy-gcn when lt decomposes to form monovalent ~ilver oxide when in contact with the queous alkaline electrolyte. Divalent silver oxide can also attack cellulosic materials in the cell, such as the separator, to form carbonate ion at the expense of even more electrolyte. These are undesirable processes because they lead to bulging of the cell, deterioration of its parts and loss of ~ervice.
U. S. Patent 3,853,623 discloses one approach to ~tabilize divalent ~ilver oxide in silver oxide/zinc/ alkaline cell through the use of gold ions incorporated inro the alkaline clec roly~e on the posi~ive ~ide of .he cell's separaror or gold oxide added ta the positive active material of ~he cell.
Canadian a~lication ~erial no. 323,519 discloses an alkaline ~ilver oxide cell employing divalent 6ilver oxide-containing electrode wherein an alu~-lnum additive i~ incorporated in the cell to improve the ~hemical ctability of the divalent silver oxide when in contact f~ ~0~
~."
'~ i 11426 ` ll~Z22C) with the cell's alkaline electrolyte.
It is an object of the present invention to provide a divalent silver oxide cell thAt will minimize internal gas pressure buildup so as to effectively eliminate distortion of the cell's housing.
It is another object of the present invention to provide a divalent silver oxide cell wherein a cadmium compound, such as cadmium oxide, is incorporated into the cell's electrolyte and/or the positive electrode so as to effectively control gas pressure builtup within the cell and thereby effectively eliminate distortion of the cell's housing.
It is another ob;ect of the present invention to incorporate a cadmium compound, such as cadmium oxide.in a divalent silver oxide cell to chemically stabilize the divalent silver oxide when in contact with the cell's aqueous electrolyte.
It is another object of the present invention to incorporate a cadmium compound, such as cadmium oxide, in a divalent silver oxide/zinc cell as an overbalance depolarizer to effectively prevent hydrogen gassing from the cathode upon complete discharge of the cell.
The foregoing and additional objects will become more fully apparent from th~ following description.
SUMMARY OF THE I~VENTION
The invention relates to a silver oxide cell having a negative electrode, An aqueous alkaline electrolyte, a positive electrode comprising a major portion of divalent -~ 11426 ~422;~:~
, silver oxide and a separator between said negative and positive electrodes,the im~rovement comprising the incorporation of a minor amount of a cadmium compound, such as ca~mium oxide, into the positi~e electrode and/or into the electrolyte of the cell to ~mprove the stability of the divalent silver oxide-containing electrode in contact with the aqueous alkaline electrolyte.
As used herein, a positive electrode or a silver electrode shall mean an electrode wherein the active cathode material is divalent silver oxide (AgO) or an electrode wherein the major active material is divalent silver oxide in conjunction with an amount below 50% by weight of novalent silver oxide CAg20) and/or some other electro-chemically active positive material.
The cadmium compound, such as cadmium oxide, may be added in the solid positive electrode andlor dissol~ed in the electrolyte. The ca~mium compound added to the positive electrode may be either admixed with the divalent silver oxide or incorporated within the divalent silver oxide crystallites themselves through coprecipitation or absorption dur$ng synthesis. Admixture of the cadmium compound and d$valent silver oxide material has the advantage of greater flexibility in the choice of the divalent silver oxide material with regard to particle size, purity and the like.
The minor amount of the cadmium compound additive for use in the positive electrode of this invention to improve the stability of the divalent silver oxide when ~ Z 2~ 11426 in contact with ~he cell's aqueous alkaline electrolyte should be between about 0.01 and about 5 per cent based on the dry weight of the divalent silver oxide in the positive electrode and prefèrably between about 0.1 and about 0.3 weight Per cent based on the try weight of the divalent silver oxide in the positive electrote. An amount of the cadmium compound less than, for example, about O.Olweight per cent, would not provide sufficient material to effectively improve the stability of the divalent silver oxide material when in contact with the aqueous alkaline electrolyte. An amount of the cadmium compound more than, for example, about 5 weight per cent added to the positive electrode would not further improve the stability of the divalent silver oxide when in contact with the aqueous alkaline electrolyte.
The cadmium compound to be added to the electrolyte in accordance with this invention should be added in an amount between about 0.0001 per cent and up to saturation of the csdmium compound in the electrolyte. For example, when using a 33 per cent potassium hydroxide solution, the upper limit would be about 0.00125 per cent based on the weight of the electroly~e. An amount of the cadmium oxide less than, for example, about 0.0001 per cent would not provide sufficient material to effectively improve the stability of the divalent silver oxide material when in contact with the aqueous alkaline electrolyte.
In addition to its use as a stabilizing agent, cadmium oxide may also be used in larger amounts ranging 6.
, ' ' ~ ','.:; ' . ' 1~4Z~:20 fr~m a~out 5 per cent to about 25 per cent by weight of the dry constituçnts of the positive electrode, as an overbalance depolarizer in a divalent silver oxide cell. An overbalance depolarizer is that part of the positive electrote in excess of the stoichiometric amount neeted to balance the negati~e electrode. Its purpose is to augment the positive electrode capacity sufficiently to prevent hydrogen gassing from the cathode upon complete discharge of the cell (anode-limited), Like divalent ~ilver oxide, a cadmium compound, such as cadmium oxide, has limited solubility in alkaline environments, discharges at a potential positive to hydrogen, and its volumetric energy density is sufficiently high so as not to impair the over-all energy density of the silver oxide/anode system. As an overbalance substitute for divalent silver oxide, its advantages are that it iæ far less costly and imparts chemical stability to the divalent silver oxide material when in contact with aqueous alkaline electrolyteO
It is al90 within the scope o~ this invention to additionally dd zinc oxide or aluminate ions to the elec-trolyte, and/or zinc oxide or aluminum oxide to the positiveelectrode. The zinc oxide and aluminate ions can be added to the electrolyte in a range between about 0.5 and about 5 per cent based on the weight of the electrolyte. When incorporatet in the positive electrode, the zinc oxide and aluminum oxide can be added in an amount between about 0.5 and about 5 and about 0.001 and about 0.1 weight per cent, respectively, baset on the dry weight of the divalent silver ll~ZZZC~
oxide in the positive electrode. Zinc oxide has been found to be more desirable than aluminum oxide. Unexpectedly, the combination of cadmium oxide in the positive electrode and zinc oxide or aluminate ions in the electrolyte produced a synergistic effect on the stability of divalent silver oxite in contact with the a~ueous alkaline electrolyte.
It is also within the scope of this invention tO
additionally add a minor amount of a stabilizer, a flow agent ant/or a lubricat~ng agent to the active positive mix to further alter the physical characteristics of the active po~itive mix for molding purposes to produce various size and type electrodes. Examples of some of these additives are ethylene bis-stearamide, ~inc stearate, lead stearate, calcium 8tearate and the like.
The silver oxide electrodes of this in~ention may , be employet in an aqueous cell system using an anode such as zinc, cadmium, in~ium or the li~e. The electrode couple so selectet can be employed with a compatible electrolyte and preferably an alkaline electrolyte. Examples of sultable electrolytes include aqueous solutions of alkaline earth metal hytroxides, 8uch as strontium hydroxide and alkali metal hytroxides, exemplified by sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide and cesium hydroxide. Com~atible mixtures of the preceding may be utilized. Preferably, the electrode of this invention should be porous so that the walls of the pores and interstices of the electrode can become wetted by the electrolyte.
EXAMPLE I
Several lots of test cells were produced each using a divalent silver oxide-containing posieive pellet having a density of 90 grams per cubic inch, a negative electrode of zinc, and a 33z KOH electrolyte. The positive electrode was positioned in a cathote collector cup with a zinc screen disposet between ehe inner surface of the cup and the positive pellet as disclosed in U. S. Patent No.
3,920,478. Next a dual separator consisting of a cellulosic barrier film and an absorbent layer, having a gold layer on that side adjacent the cathode, was disposed on top of the positive pellet followed by the zinc electrode, An anode cup containing the zinc electrode was then placed over the cathode Sup and sealed thereto in a conventional manner.
The exact constituents of the positive electrode ant any attitives to the electrolyte are shown in Table 1.
The cells were stored for three month~ under various temperature conditions. Thereafter the cells were mea~ured for any bulging ant the results obtained for each test lot were veraged and are shown in Table 2 along w~th the maximum cell bulge observed in each lot. In addition, the service life to a 1.3 volt cutoff was observed and is also shown in Table 2, . .
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llf~22ZO
The resulta of the data shown in Table 2 illu~trate that using the teachings of this invention, a cadmium compound additive with or without zinc oxide and aluminum addi~ives can be offectively used to stabilize divalent silver oxide when in contact with an aqueous a~kaline electrolyte ~o as to reduce cell bulging, Aa also illustrated, the combination of a cadmium com-pound in the po~itive olectrode and zinc oxide or aluminate ions in the eloctrolyte produced a synergistic effect on the stability of divalent silver oxide in contact with aqueous alkaline electrolyte.
That ia, the addition of both a cadmium compound in the positive clectrode and zinc oxide or aluminate ions to the elqctrolyte reduced bulge more than the composite of either material acting alone. This i9 ~hown fo~ example by comparing te-t Lot 23 with Lots 16, 17, and 19 for ZnO addition to the electrolyte, and by comparing Lot 22 with Lot~ 16, 18, and 19 for aluminate addition to the electrolyte.
EXAMPLE II
.
Several test lots of cells were produced as described in Example I except that the cathode and electrolyte compositions employed are as shown in Table 3. The reoults of the data shown in Table 3 illu~trate the benefits as expressed above in Example I in that the cadmium compound additive reduces cell bulging. Both Example I
and Example ~T ~how that the addition of the cadmium compound by admixture give~ slightly better bulge control than by coprecipitation.
14.
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The exact constituents of the positive electrode ant any attitives to the electrolyte are shown in Table 1.
The cells were stored for three month~ under various temperature conditions. Thereafter the cells were mea~ured for any bulging ant the results obtained for each test lot were veraged and are shown in Table 2 along w~th the maximum cell bulge observed in each lot. In addition, the service life to a 1.3 volt cutoff was observed and is also shown in Table 2, . .
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. ~ ~i o ,~ o ~ C
, U~ o Y~ o U~ U~ o ~ U~ o o o o~
_l ~ ~ ~o o ~ X o C`J
~ 3 o , _, o _, o ,, , ~ -~ ~ C
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: ~ ~ _, o ~ ( O r~
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. ~ O U~ ~ O ~ O. ~ ~ O. In ~ e :: ~ : ~ ~_ O O O ~, 0, 0 0 ~1 0 0 0 0~
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.
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13 .
llf~22ZO
The resulta of the data shown in Table 2 illu~trate that using the teachings of this invention, a cadmium compound additive with or without zinc oxide and aluminum addi~ives can be offectively used to stabilize divalent silver oxide when in contact with an aqueous a~kaline electrolyte ~o as to reduce cell bulging, Aa also illustrated, the combination of a cadmium com-pound in the po~itive olectrode and zinc oxide or aluminate ions in the eloctrolyte produced a synergistic effect on the stability of divalent silver oxide in contact with aqueous alkaline electrolyte.
That ia, the addition of both a cadmium compound in the positive clectrode and zinc oxide or aluminate ions to the elqctrolyte reduced bulge more than the composite of either material acting alone. This i9 ~hown fo~ example by comparing te-t Lot 23 with Lots 16, 17, and 19 for ZnO addition to the electrolyte, and by comparing Lot 22 with Lot~ 16, 18, and 19 for aluminate addition to the electrolyte.
EXAMPLE II
.
Several test lots of cells were produced as described in Example I except that the cathode and electrolyte compositions employed are as shown in Table 3. The reoults of the data shown in Table 3 illu~trate the benefits as expressed above in Example I in that the cadmium compound additive reduces cell bulging. Both Example I
and Example ~T ~how that the addition of the cadmium compound by admixture give~ slightly better bulge control than by coprecipitation.
14.
.
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.
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Claims
1. A silver oxide cell having a negative electrode, an aqueous alkaline electrolyte, a positive electrode comprising a major portion of divalent silver oxide and a separator between said negative electrode and the positive electrode, the improvement comprising the addition of cadmium oxide into the positive electrode in an amount between about 5 and about 25 per cent based on the weight of the dry constituents of the positive electrode and wherein the aqueous alkaline electrolyte contains a minor amount of zinc oxide or aluminate ions, 16.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000387244A CA1142220A (en) | 1979-02-28 | 1981-10-02 | Cadium compound additive for cells using divalent silver oxide |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA322,622A CA1128121A (en) | 1978-03-30 | 1979-02-28 | Cadium compound additive for cells using divalent silver oxide |
| CA000387244A CA1142220A (en) | 1979-02-28 | 1981-10-02 | Cadium compound additive for cells using divalent silver oxide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1142220A true CA1142220A (en) | 1983-03-01 |
Family
ID=25668886
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000387244A Expired CA1142220A (en) | 1979-02-28 | 1981-10-02 | Cadium compound additive for cells using divalent silver oxide |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1142220A (en) |
-
1981
- 1981-10-02 CA CA000387244A patent/CA1142220A/en not_active Expired
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