CA1038030A - Silver-ii-oxide for galvanic elements - Google Patents
Silver-ii-oxide for galvanic elementsInfo
- Publication number
- CA1038030A CA1038030A CA230,100A CA230100A CA1038030A CA 1038030 A CA1038030 A CA 1038030A CA 230100 A CA230100 A CA 230100A CA 1038030 A CA1038030 A CA 1038030A
- Authority
- CA
- Canada
- Prior art keywords
- oxidant
- silver
- solution
- oxide
- added
- 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
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- H01M4/00—Electrodes
- H01M4/02—Electrodes composed of, or comprising, active material
- H01M4/36—Selection of substances as active materials, active masses, active liquids
- H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
- H01M4/54—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides of silver
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G5/00—Compounds of silver
-
- C—CHEMISTRY; METALLURGY
- C30—CRYSTAL GROWTH
- C30B—SINGLE-CRYSTAL GROWTH; UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL; PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; APPARATUS THEREFOR
- C30B7/00—Single-crystal growth from solutions using solvents which are liquid at normal temperature, e.g. aqueous solutions
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Inorganic Chemistry (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Crystallography & Structural Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- General Chemical & Material Sciences (AREA)
- Battery Electrode And Active Subsutance (AREA)
- Crystals, And After-Treatments Of Crystals (AREA)
- Agricultural Chemicals And Associated Chemicals (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Silver-II-oxide for use in galvanic elements is produced by adding an oxidant to a metallic silver powder suspension in an alkaline solution.
An exceptionally stable material results.
Silver-II-oxide for use in galvanic elements is produced by adding an oxidant to a metallic silver powder suspension in an alkaline solution.
An exceptionally stable material results.
Description
~038~30 : ' This invention relates to a process for producing silver-II-oxide for galvanic elements, and particularly for silver-II-oxide zinc primary elements.
In order that such silver-II-oxlde z:inc prlmary elements shall have long llfe~ as is desirable if they are to be used to power watches, the silver-II-oxide must have high ~bermodynamic stability in order to achieve long sh~lf life.
The thermodynamic decomposition of silver-II-oxide in alkaline solution takes place in accordance with the equation
In order that such silver-II-oxlde z:inc prlmary elements shall have long llfe~ as is desirable if they are to be used to power watches, the silver-II-oxide must have high ~bermodynamic stability in order to achieve long sh~lf life.
The thermodynamic decomposition of silver-II-oxide in alkaline solution takes place in accordance with the equation
2 AgO ~Ag20 + 1/2 0~
It is customary to produce silver-II-oxide destined for use in such primary elements by anodic oxidation of silver salts in an alkaline medium~ or by electrolysis of a ~i:lver nitrate solution followed by washing and cook:ing, or by the action of ozone upon silver powder. Production by ozone treatment is comparatively costly, demanding of resources, and time consuming.
~(~!3803~
Moreover, by use of these known processes one normally obtains products which exhibit high internal disc~arge. T~is is believedtto be attributable to inadequate electro-chemical stabilit~ o the silver powder. This high internal discharge rate is particularly undesirable for ~atch batteries since it causes the hermetically sealed cell to become distended.
The present invention attempts to produce a silver-II-oxide having comparatively low internal discharge, a comparatively low decomposition rate, and a silver-II-oxide cell having extended shelf life.
The silver-II-oxide thus pro~ided is preferably monoclinic crystalline silver-II-oxide.
It is another object to provide an improved electrode mass capable o sustaining high load currents.
~ccording to the present invention, thore is providocl a procoss for producing silvor~ oxlde eor galvanic olemonts, the improvemont which comprises adding an oxidant to an alkaline solution containing undissolved metallic silver powder, thereby oxidizlng the powder to silver-II-oxide, the oxidant being potassium peroxidisulate.
Preferably, the treatment takes place in caustic soda solution.
The foregoing oxidizing agent is particularly characterized b~ a high resulting level of oxidation and by convenience of usage.
.~
~03~03~
To practice the process of the invention, silver powder is suspend-~*do in an alkaline medium, such as an aqueous NaO~ solution or KOH solution.
The solution is heated to speed up the reaction, for example to the range of about 50 to 95& . After reaching a predetermined temperature~ the oxidant is added, preferably in incremental portions, the total quantity being such that it provides at least complete transformation of the silver powder to silver-II-oxide. Preferably an excess of oxidant is used. Up to twdce the minimum quantity of oxidant necessary to achieve complete transformation may be uti-lized. As an example, 28 grams of the above mentioned oxidant would be the minimunlquant~y for the transformation of 10 grams of silver powder.
ample:
In 1.5 liters o~ ~queous solution containlng 150 grams o~ sodium hydroxide, 65 grams o~ silver powder arc suspended with continuous stirring.
The silver powder has a density of approximately 1.6 grams per cubic centi-meter. Its grain size distribution is: 52% under 10 microns; 33% 10 microns to 30 microns, 15~ above 30 microns.
; The liquid is then heated to about 85 C. Upon reaching this temper-ature, a total of 200 grams of potassium peroxidisulfate (K2S208) in portions of about 40 grams each is added at intervals of, for example3 one hour. After addition of the final portion of oxidant, stirring is continued for three hours. The product is then filtered; washed to free it of alkali substances, dried ~t a temperature of approximately 80 C and reduced to particle form.
The foregoing yields approximately 73 grams of silver-II-oxide with more than 95% content of pure silver-II-oxide. The silver oxide producedils characterized by high thermodynamic stability~ low internal discharge and con-sequent long shelf life. The rate of gas evolution of these products in 18%
NaOH is below one microliter per gram-hour at room temperature. This stability is attributable to the fact that the process embodying the invention produces single crystals of exceptionally regular shape and monoclinic form.
g~38030 While not wishing to be bound by this, it is believed that the monoclinic crystalline structure is particularly advantageous for use in an electrode mass because it is capable of bearing high current loads. Large surface area and low internal resistance are conductive to this.
Instead of step-by-step addition of the oxidant as described in the specific example above, it i9 also possible to use continuous addition, as for example by drop-by-drop introduction.
The oxidant, of which a specific example is provided above, must be active in alkaline media, inasmuch as the AgO is a basic oxide. Only those oxidants are suitable which have a higher reduction potential than the Ag20/
AgO system.
A particu:l.ar advantage of the invention, as comparcd wLth convont-ional processes, such as those using ozone to oxidize ~gO, is the low cost of the technique~
It is customary to produce silver-II-oxide destined for use in such primary elements by anodic oxidation of silver salts in an alkaline medium~ or by electrolysis of a ~i:lver nitrate solution followed by washing and cook:ing, or by the action of ozone upon silver powder. Production by ozone treatment is comparatively costly, demanding of resources, and time consuming.
~(~!3803~
Moreover, by use of these known processes one normally obtains products which exhibit high internal disc~arge. T~is is believedtto be attributable to inadequate electro-chemical stabilit~ o the silver powder. This high internal discharge rate is particularly undesirable for ~atch batteries since it causes the hermetically sealed cell to become distended.
The present invention attempts to produce a silver-II-oxide having comparatively low internal discharge, a comparatively low decomposition rate, and a silver-II-oxide cell having extended shelf life.
The silver-II-oxide thus pro~ided is preferably monoclinic crystalline silver-II-oxide.
It is another object to provide an improved electrode mass capable o sustaining high load currents.
~ccording to the present invention, thore is providocl a procoss for producing silvor~ oxlde eor galvanic olemonts, the improvemont which comprises adding an oxidant to an alkaline solution containing undissolved metallic silver powder, thereby oxidizlng the powder to silver-II-oxide, the oxidant being potassium peroxidisulate.
Preferably, the treatment takes place in caustic soda solution.
The foregoing oxidizing agent is particularly characterized b~ a high resulting level of oxidation and by convenience of usage.
.~
~03~03~
To practice the process of the invention, silver powder is suspend-~*do in an alkaline medium, such as an aqueous NaO~ solution or KOH solution.
The solution is heated to speed up the reaction, for example to the range of about 50 to 95& . After reaching a predetermined temperature~ the oxidant is added, preferably in incremental portions, the total quantity being such that it provides at least complete transformation of the silver powder to silver-II-oxide. Preferably an excess of oxidant is used. Up to twdce the minimum quantity of oxidant necessary to achieve complete transformation may be uti-lized. As an example, 28 grams of the above mentioned oxidant would be the minimunlquant~y for the transformation of 10 grams of silver powder.
ample:
In 1.5 liters o~ ~queous solution containlng 150 grams o~ sodium hydroxide, 65 grams o~ silver powder arc suspended with continuous stirring.
The silver powder has a density of approximately 1.6 grams per cubic centi-meter. Its grain size distribution is: 52% under 10 microns; 33% 10 microns to 30 microns, 15~ above 30 microns.
; The liquid is then heated to about 85 C. Upon reaching this temper-ature, a total of 200 grams of potassium peroxidisulfate (K2S208) in portions of about 40 grams each is added at intervals of, for example3 one hour. After addition of the final portion of oxidant, stirring is continued for three hours. The product is then filtered; washed to free it of alkali substances, dried ~t a temperature of approximately 80 C and reduced to particle form.
The foregoing yields approximately 73 grams of silver-II-oxide with more than 95% content of pure silver-II-oxide. The silver oxide producedils characterized by high thermodynamic stability~ low internal discharge and con-sequent long shelf life. The rate of gas evolution of these products in 18%
NaOH is below one microliter per gram-hour at room temperature. This stability is attributable to the fact that the process embodying the invention produces single crystals of exceptionally regular shape and monoclinic form.
g~38030 While not wishing to be bound by this, it is believed that the monoclinic crystalline structure is particularly advantageous for use in an electrode mass because it is capable of bearing high current loads. Large surface area and low internal resistance are conductive to this.
Instead of step-by-step addition of the oxidant as described in the specific example above, it i9 also possible to use continuous addition, as for example by drop-by-drop introduction.
The oxidant, of which a specific example is provided above, must be active in alkaline media, inasmuch as the AgO is a basic oxide. Only those oxidants are suitable which have a higher reduction potential than the Ag20/
AgO system.
A particu:l.ar advantage of the invention, as comparcd wLth convont-ional processes, such as those using ozone to oxidize ~gO, is the low cost of the technique~
Claims (11)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. In a process for producing silver-II-oxide for galvanic elements, the improvement which comprises adding an oxidant to an alkaline solution containing undissolved metallic silver powder, thereby oxidizing the powder to silver-II-oxide, the oxidant being potassium peroxidisulfate.
2. The process of claim 1 further comprising forming a suspension of the powder in the solution before the oxidant is added.
3. The process of claim 1 wherein the solution is an aqueous solution of sodium hydroxide.
4. The process of claim 1 further comprising heating the solution to approximately 50° to 95° C during the addition of oxidant.
5. The process of claim 1 wherein the solution is heated to a temperature of about 85° C before the addition of oxidant.
6. The process of claim 1 wherein the oxidant is added in incremental portions.
7. The process of claim 1 wherein a quantity of oxidant is added in excess of that sufficient to oxidize all the silver powder.
8. The process of claim 1 further comprising filtering the solids from the solution, washing them to remove alkaline substances, and drying them.
9. The process of claim 7 wherein up to two times the quantity necessary to oxidize all the silver powder is added.
10. The process of claim 8 further comprising reducing the dried material to particle form.
11. The process of claim 10 further comprising incorporating the material reduced to particle form into a galvanic element.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE2430910A DE2430910C3 (en) | 1974-06-27 | 1974-06-27 | Process for the production of silver (H) oxide for galvanic elements |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1038030A true CA1038030A (en) | 1978-09-05 |
Family
ID=5919121
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA230,100A Expired CA1038030A (en) | 1974-06-27 | 1975-06-25 | Silver-ii-oxide for galvanic elements |
Country Status (14)
| Country | Link |
|---|---|
| US (1) | US4003757A (en) |
| JP (1) | JPS5813498B2 (en) |
| AT (1) | AT342130B (en) |
| BE (1) | BE826309A (en) |
| CA (1) | CA1038030A (en) |
| CH (1) | CH593210A5 (en) |
| DE (1) | DE2430910C3 (en) |
| DK (1) | DK143267C (en) |
| FR (1) | FR2276267A1 (en) |
| GB (1) | GB1456476A (en) |
| IT (1) | IT1037858B (en) |
| NL (1) | NL7506758A (en) |
| SE (1) | SE398226B (en) |
| SU (1) | SU689611A3 (en) |
Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2702145C3 (en) * | 1976-02-09 | 1981-06-04 | Union Carbide Corp., 10017 New York, N.Y. | Process for the production of a doped α-alumina single crystal oriented in the r-plane and having a circular cross-section |
| DE2732082C3 (en) * | 1976-07-16 | 1985-01-03 | Hitachi Maxell, Ltd., Ibaraki, Osaka | Galvanic silver (II) oxide cell and process for their manufacture |
| JPS53113797A (en) * | 1977-03-16 | 1978-10-04 | Hitachi Maxell Ltd | Production of silver(ii) oxide for cell |
| GB2003455B (en) * | 1977-08-19 | 1982-02-24 | Matsushita Electric Industrial Co Ltd | Divalent silver oxide for use in primary cells and manufacturing method thereof |
| US4755266A (en) * | 1986-07-11 | 1988-07-05 | The Dow Chemical Company | Process for silver cathode activation |
| US4913781A (en) * | 1987-09-18 | 1990-04-03 | Gould Inc. | Microporous elemental silver and method |
| US4913782A (en) * | 1987-09-18 | 1990-04-03 | Gould Inc. | Microporous elemental silver article and method |
| US4851310A (en) * | 1987-09-18 | 1989-07-25 | Gould Inc. | Microporous elemental silver article and method |
| US5389469A (en) * | 1993-06-14 | 1995-02-14 | Rayovac Corporation | AgO battery, and material |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2528891A (en) * | 1945-03-26 | 1950-11-07 | Herbert E Lawson | Primary battery depolarizer and method of making the same |
| US2670273A (en) * | 1947-04-10 | 1954-02-23 | John E Munn | Conversion of metals into metal oxides and hydroxides |
| US2758014A (en) * | 1953-04-23 | 1956-08-07 | Glidden Co | Catalytic process for preparing cuprous oxide from mixed copper oxides |
-
1974
- 1974-06-27 DE DE2430910A patent/DE2430910C3/en not_active Expired
-
1975
- 1975-02-03 AT AT78475A patent/AT342130B/en not_active IP Right Cessation
- 1975-03-05 BE BE154018A patent/BE826309A/en not_active IP Right Cessation
- 1975-03-25 CH CH379675A patent/CH593210A5/xx not_active IP Right Cessation
- 1975-03-26 FR FR7509480A patent/FR2276267A1/en active Granted
- 1975-03-27 SE SE7503628A patent/SE398226B/en unknown
- 1975-04-09 DK DK153175A patent/DK143267C/en not_active IP Right Cessation
- 1975-04-11 SU SU752121997A patent/SU689611A3/en active
- 1975-05-05 IT IT23018/75A patent/IT1037858B/en active
- 1975-05-22 GB GB2232175A patent/GB1456476A/en not_active Expired
- 1975-06-06 NL NL7506758A patent/NL7506758A/en not_active Application Discontinuation
- 1975-06-23 US US05/589,562 patent/US4003757A/en not_active Expired - Lifetime
- 1975-06-24 JP JP50078598A patent/JPS5813498B2/en not_active Expired
- 1975-06-25 CA CA230,100A patent/CA1038030A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| SE398226B (en) | 1977-12-12 |
| DK143267C (en) | 1981-11-30 |
| CH593210A5 (en) | 1977-11-30 |
| DK153175A (en) | 1975-12-28 |
| DK143267B (en) | 1981-08-03 |
| BE826309A (en) | 1975-06-30 |
| FR2276267A1 (en) | 1976-01-23 |
| AT342130B (en) | 1978-03-10 |
| AU8039175A (en) | 1976-10-28 |
| FR2276267B1 (en) | 1981-05-22 |
| GB1456476A (en) | 1976-11-24 |
| JPS5813498B2 (en) | 1983-03-14 |
| NL7506758A (en) | 1975-12-30 |
| JPS5118994A (en) | 1976-02-14 |
| IT1037858B (en) | 1979-11-20 |
| DE2430910A1 (en) | 1976-01-15 |
| DE2430910B2 (en) | 1980-05-08 |
| SU689611A3 (en) | 1979-09-30 |
| DE2430910C3 (en) | 1981-01-08 |
| SE7503628L (en) | 1975-12-29 |
| ATA78475A (en) | 1977-07-15 |
| US4003757A (en) | 1977-01-18 |
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