DENDRITE-INHIBITING ADDITIVE FOR BATTERY CELL HAVING ZINC ELECTRODE

• US 3,660,170 A
• Filed: 04/08/1970
• Issued: 05/02/1972
• Est. Priority Date: 04/08/1970
• Status: Expired due to Term

• Current Assignee: Gates Energy Products, Inc. (Schneider Electric SE)
• Original Assignee: Guy Rampel
• Inventors: Rampel, Guy
• Primary Examiner(s): Walton, Donald L.
• Application Number:
  US05/026,607
• Time in Patent Office: 755 Days
• Field of Search: 136/30,154,6 204/55 260/89.7N,88.3R
• US Class Current: 429/347
• CPC Class Codes: H01M 10/24 Alkaline accumulators
• CPC Class Codes: H01M 10/26 Selection of materials as electrolytes
• CPC Class Codes: H01M 4/244 Zinc electrodes
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

To inhibit the formation of overgrowth of excessive dendritic zinc, for example during recharging of a rechargeable electrolytic battery cell, or in electroplating, the electrolyte contains an additive consisting essentially of a cationic high molecular weight organic linear polymer which has a positive ion radical of substituted ammonium which may be one of a large number of related ammonium polymers, preferably quaternary. The quaternary nitrogen in the molecule can be part of a ring which may include the adjacent carbon atom for any two of the nitrogen'"'"''"'"'s four substituent radicals, and the ring may also include ether linkages. The polymer compound is water soluble and is soluble in the electrolyte of the cell to the extent required to be effective for proper charge and discharge operation of the cell. The additive may be dissolved in the electrolyte directly, or may be added as a coating on the separator film, or be an ingredient of the paste-type anode. A preferred embodiment of the invention comprises, as the additive, diallyldimethylammonium hydroxide polymer.

Claims

2. The combination according to claim 1, said positive and negative electrodes and said aqueous liquid together defining a rechargeable battery cell, said negative electrode containing zinc.

3. The combination according to claim 2, said aqueous liquid containing an alkaline electrolyte.

4. The combination according to claim 1, said positive and negative electrodes and said aqueous liquid together defining a zinc electroplating system.

5. The combination according to claim 1, said positive and negative electrodes and said aqueous liquid together defining a rechargeable electrolytic battery cell, said positive electrode comprising a porous plate cathode, said negative electrode comprising a zinc-containing anode, said electrolyte comprising an alkaline metal hydroxide, said dendrite-inhibiting agent being present in said aqueous liquid in an amount from about 0.1 percent to about 10 percent by weight, based on the total weight of zinc in said zinc-containing cathodes.

6. The combination according to claim 3, said positive electrode comprising a porous plate cathode, said negative electrode comprising a zinc-containing anode, said electrolyte containing from 10 percent to about 40 percent of an alkali metal hydroxide, said dendrite-inhibiting agent being present in said electrolyte in an amount from 0.1 percent up to a maximum of about 10 percent and not exceeding the limit of its solubility in said electrolyte.

7. The combination according to claim 2, said negative electrode comprising a pasted-type anode including a current collector, a cohesive body of finely divided rechargeable active zinc-containing material, said dendrite-inhibiting agent being incorporated as a binder in said cohesive body in an amount from about 0.1 to 10.0 percent by weight, based on the quantity of zinc in said negative electrode.

8. The combination according to claim 1, said positive ion of said organic cationic polymer being monovalent diallyldimethylammonium.

9. The combination according to claim 8, said positive ion having associated therewith a hydroxyl anion.

10. The combination according to claim 4, said positive electrode containing zinc, said aqueous liquid containing zinc ions, and said additive dendrite-inhibiting agent being present in said liquid in an amount of from 0.1 percent to 10 percent by weight of said liquid.

11. The combination according to claim 2, said rechargeable cell having an ionically permeable membrane between said positive and negative electrodes, said dendrite-inhibiting agent in said liquid being present as a coating on said membrane and adapted to be dissolved in said aqueous liquid.

12. In combination with opposed positive and negative electrodes immersed in an aqueous liquid wherein one of the electrodes contains zinc, an additive zinc dendrite-inhibiting agent in said liquid consisting essentially of an organic cationic polymer having a homopolymeric molecular chain of repeating units which in aqueous solution forms positive ions of a formula selected from the group consisting of: