Voltage and reduced polarization within mercury free zinc air cells

Patent metadata

Field	Value
Publication number	US-9786922-B2
Application number	US-201313945383-A
Country	US
Kind code	B2
Filing date	Jul 18, 2013
Priority date	Aug 21, 2012
Publication date	Oct 10, 2017
Grant date	Oct 10, 2017

Abstract

The present disclosure is directed to a zinc air cell with improved voltage and reduced polarization. The combination of an anode corrosion inhibitor with a surfactant system yields enhanced cell voltage and capacity for the cell that are above the individual contributions of the corrosion inhibitor and the surfactant system.

First claim

What is claimed is:

1. A zinc-air cell comprising:
a cathode;
an anode comprising an anode mix, wherein the anode mix comprises a polyaniline corrosion inhibitor and an electrolyte comprising a surfactant system; wherein the surfactant system comprises a hexyl diphenyl oxide disulfonic acid surfactant and at least one amphoteric surfactant; and
a separator disposed between the anode and the cathode;
wherein the hexyl diphenyl oxide disulfonic acid surfactant is present in an amount of from about 500 ppm to about 5,000 ppm, by weight of the electrolyte;
the at least one amphoteric surfactant is present in an amount of from about 500 ppm to about 5,000 ppm, by weight of the electrolyte; and
the polyaniline is present in an amount of from about 100 ppm to about 500 ppm, by weight of the anode mix.

2. The zinc-air cell of claim 1 , wherein the at least one amphoteric surfactant has a formula

wherein:
R 1 is an alkyl group having between 8 and 30 unbranched carbon atoms;
R 2 is an alkyl group having between 1 to about 6 unbranched carbon atoms, optionally substituted with 1 or more hydroxyl substituents;
R 3 is selected from a polyethylene oxide group having between 3 and 40 ethylene oxide units and a polypropylene oxide group having between 1 to 10 propylene oxide units; and
X is an anionic acid group, an anionic acid ester, or an alkali metal salt of an anionic acid or acid ester.

3. The zinc-air cell of claim 1 , wherein the at least one amphoteric surfactant has a formula

wherein
R 4 is an unbranched alkyl group having between 8 and 30 unbranched carbon atoms that form an aliphatic fatty amine when bound to the nitrogen atom;
R 5 is selected from a polyethylene oxide group having between 3 and 40 ethylene oxide units and a polypropylene oxide group having between 1 and 10 propylene oxide units; and
R 6 is selected from hydrogen, a polyethylene oxide group having between 3 and 40 ethylene oxide units and a polypropylene oxide group having between 1 and 10 polypropylene oxide units.

4. The zinc-air cell of claim 1 , wherein the surfactant system comprises a mixture of amphoteric surfactants, wherein the first amphoteric surfactant has a formula

wherein:
R 1 is an alkyl group having between 8 and 30 unbranched carbon atoms;
R 2 is an alkyl group having between 1 to about 6 unbranched carbon atoms, optionally substituted with 1 or more hydroxyl substituents;
R 3 is selected from a polyethylene oxide group having between 3 and 40 ethylene oxide units and a polypropylene oxide group having between 1 to 10 propylene oxide units; and
X is an anionic acid group, an anionic acid ester, or an alkali metal salt of an anionic acid or acid ester; and the second amphoteric surfactant has a formula

wherein
R 4 is an unbranched alkyl group having between 8 and 30 unbranched carbon atoms that form an aliphatic fatty amine when bound to the nitrogen atom;
R 5 is selected from a polyethylene oxide group having between 3 and 40 ethylene oxide units and a polypropylene oxide group having between 1 and 10 propylene oxide units; and
R 6 is selected from hydrogen, a polyethylene oxide group having between 3 and 40 ethylene oxide units and a polypropylene oxide group having between 1 and 10 polypropylene oxide units.

5. The zinc-air cell of claim 1 , wherein the surfactant system comprises a mixture of amphoteric surfactants, wherein the mixture comprises one or more polyethoxylated fatty amino carboxylates and one or more polyethoxylated fatty amines.

6. The zinc-air cell of claim 1 , wherein the polyaniline is a polyaniline emeraldine base.

Assignees

• Spectrum Brands Inc

Inventors

• Pratt Paul

Classifications

• H01M6/045

  characterised by aqueous electrolyte · CPC title

• H01M12/06

  with one metallic and one gaseous electrode · CPC title

• H01M4/628

  Inhibitors, e.g. gassing inhibitors, corrosion inhibitors · CPC title

• H01M2300/0002

  Aqueous electrolytes · CPC title

• H01M4/12 Primary

  of consumable metal or alloy electrodes (use of alloy compositions as active materials H01M4/38) · CPC title