REDUCED MERCURY CONTAINING ZINC ALKALINE CELLS

• US 3,847,669 A
• Filed: 08/03/1973
• Issued: 11/12/1974
• Est. Priority Date: 10/01/1971
• Status: Expired due to Term

• Current Assignee: Eveready Battery Company Incorporated (Energizer Holdings, Inc.)
• Original Assignee: Sam C. Paterniti
• Inventors: Paterniti, Sam C.
• Primary Examiner(s): McCarthy, Helen M.
• Assistant Examiner(s): Le Fevour, C. F.
• Application Number:
  US05/385,309
• Time in Patent Office: 466 Days
• Field of Search: 136/30,102,107,125-130,153,154
• US Class Current: 429/206
• CPC Class Codes: H01M 4/38 of elements or alloys
• CPC Class Codes: H01M 4/628 Inhibitors, e.g. gassing inhibitors, corrosion inhibitors
• CPC Class Codes: H01M 6/06 Dry cells, i.e. cells wherein the electrolyte is rendered non-fluid

Abstract

The proportion of mercury needed in alkaline zinc-manganese dioxide cells to provide adequate shelf life is reduced by incorporating in such cells an ethylene oxide polymer.

Claims

1. A GALVANIC CELL HAVING A ZINC ANODE, A MANGANESE DIOXIDE CATHODE AND AN ALKALINE ELECTROLYTE, SAID ZINC ANODE CONTAINING LESS THAN 8 PERCENT MERCURY BASED ON THE WEIGHT OF THE ZINC ANODE, SAID CELL ALSO CONTAINING AN ETHYLENE OXIDE POLYMER SELECTED FROM THE GROUP CONSISTING OF DIETHYLENE GLYCOL, TRIETHYLENE GLYCOL, POLYETHYLENE GLYCOL HAVING AN AVERAGE MOLECULAR WEIGHT OF FROM ABOUT 190 TO ABOUT 7,000, C4 AND LOWER ALKYL ETHERS THEREOF AND C4 AND LOWER ALKANOATE ESTERS THEREOF, SAID ETHYLENE OXIDE POLYMER AND SAID MERCURY IN COMBINATION PROVIDING AN IMPROVED STORAGE STABILITY UNDER COMPARABLE CONDITIONS FOR SAID CELL AS PROVIDED BY A CELL OTHERWISE IDENTICAL BUT CONTAINING THE SAME QUANTITY OF MERCURY IN THE ABSENCE OF SAID ETHYLENE OXIDE POLYMER.

2. the cell of claim 1 wherein the alkaline electrolyte is aqueous potassium hydroxide.

3. The cell of claim 2 wherein the ethylene oxide polymer is present in the cell in an amount greater than about 0.01 weight per cent, based on weight of said zinc.

4. The cell of claim 2 wherein the ethylene oxide polymer is present in the cell in an amount greater than about 0.1 weight per cent, based on weight of said zinc.

5. The cell of claim 3 wherein the ethylene oxide polymer is present in an amount of from about 0.01 to about 1 weight per cent based on weight of said zinc.

6. The cell of claim 4 wherein the ethylene oxide polymer is present in an amount of from about 0.1 to about 1 weight per cent, based on weight of said zinc.

7. The cell of claim 2 wherein the ethylene oxide polymer is polyethylene glycol or methoxy polyethylene glycol having an average molecular weight of from about 300 to about 700.