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US4136236A Expired / Lapsed US ⏱️ 0.0 years remaining

Long-life alkaline primary battery

Assignee: Leclanche SA
•
Filing: 1977-04-27
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Granted: 1979-01-23
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Expires: 1997-04-27
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Abstract

Abstract This invention relates to an alkaline primary battery of the type having a negative electrode containing cadmium or amalgamated zinc and a positive electrode containing monovalent silver oxide, mercuric oxide, or mixtures of these oxides with manganese dioxide, the positive electrode having an electrochemically active surface area facing the negative electrode. At positive electrodes, self-discharge can be caused by the solubility of the active material. It is an object of this invention to provide an improved alkaline primary battery designed to reduce this type of self-discharge, without impairing the internal resistance of the battery. To this end, in the alkaline primary battery the improvement comprises at least one electrically conductive, microporous, electrolyte-saturated, optically opaque filter-electrode which covers the entire active surface area of the positive electrode, contains either no monovalent silver oxide nor mercuric oxide or only a substantially smaller amount thereof per unit of volume than the positive electrode, contains electrically conductive material which is not corroded, oxidized, nor dissolved in alkali electrolytes at the given potential of the positive electrode, and is in electrical contact with the positive electrode.

Inventors

  • 👤 Paul Ruetschi

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 10:36
CPC Classifications
H; H01; H01M; H01M6/00; H01M6/04; H01M6/06; H01M4/00; H01M4/02; H01M4/06; Y; Y02; Y02E; Y02E60/00; Y02E60/10

Claims Analysis

Total Claims: 8
Claim 1
Independent Claim 148 words
In an alkaline primary battery of the type having a negative electrode containing cadmium or amalgamated zinc and a positive electrode containing monovalent silver oxide, mercuric oxides or mixtures of these oxides with manganese dioxide, the positive electrode having an electrochemically active surface area facing said negative electrode, said primary battery comprising at least one electrically conductive, microporous, electrolyte saturated, optically opaque filter electrode which covers the entire said electrochemically active surface area of said positive electrode, said filter electrode containing electrically conductive material which is not corroded, oxidized nor dissolved in alkali electrolytes at the given potential of said positive electrode and is in electrical contact with said positive electrode, wherein said filter electrode contains, in addition to said conductive material, a very finely divided, surface-rich second substance which is insoluble in alkali electrolytes and is not attacked or dissolved at the potential of said positive electrode.
Claim 2
Dependent Claim 148 words
In an alkaline primary battery of the type having a negative electrode containing cadmium or amalgamated zinc and a positive electrode containing monovalent silver oxide, mercuric oxides or mixtures of these oxides with manganese dioxide, the positive electrode having an electrochemically active surface area facing said negative electrode, said primary battery comprising at least one electrically conductive, microporous, electrolyte saturated, optically opaque filter electrode which covers the entire said electrochemically active surface area of said positive electrode, said filter electrode containing electrically conductive material which is not corroded, oxidized nor dissolved in alkali electrolytes at the given potential of said positive electrode and is in electrical contact with said positive electrode, wherein said filter electrode contains, in addition to said conductive material, a very finely divided, surface-rich second substance which is insoluble in alkali electrolytes and is not attacked or dissolved at the potential of said positive electrode.
Claim 3
Dependent Claim 15 words
An alkaline primary battery in accordance with claim 1, wherein said substance is carbon black.
Claim 4
Dependent Claim 15 words
An alkaline primary battery in accordance with claim 1, wherein said substance is activated carbon.
Claim 5
Dependent Claim 15 words
An alkaline primary battery in accordance with claim 1, wherein said substance is manganese dioxide.
Claim 6
Dependent Claim 15 words
An alkaline primary battery in accordance with claim 1, wherein said substance is cadmium hydroxide.
Claim 7
Dependent Claim 15 words
An alkaline primary battery in accordance with claim 1, wherein said substance is nickel hydroxide.
Claim 8
Dependent Claim 15 words
An alkaline primary battery in accordance with claim 1, wherein said substance is aluminum oxide.

References Cited (Backward Citations)

US3178314A Cited
US3427203A Cited
US3485672A Cited
US3673000A Cited
US3961985A Cited
US4015055A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-01-22 1982-07-24 1983-01-23 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-01-22 1986-07-24 1987-01-23 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-01-22 1990-07-24 1991-01-23 $7700.00 Window Closed / Lapsed

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