Anode cross-sectional characteristic gradient

Patent metadata

Field	Value
Publication number	US-11322752-B2
Application number	US-201815896917-A
Country	US
Kind code	B2
Filing date	Feb 14, 2018
Priority date	Mar 10, 2017
Publication date	May 3, 2022
Grant date	May 3, 2022

Abstract

Various embodiments are directed to an electrochemical cell having a non-homogeneous anode. The electrochemical cell includes a container, a cathode forming a hollow cylinder within the container, an anode positioned within the hollow cylinder of the cathode, and a separator between the cathode and the anode. The anode defines a characteristic gradient between an interior portion of the anode and the outermost surface of the anode adjacent the separator. The characteristic gradient may be defined as, for example, an average active material particle size within the anode that changes as a function of the radial location within the anode or a surfactant concentration gradient that changes as a function of the radial location within the anode.

First claim

That which is claimed:

1. A primary alkaline electrochemical cell comprising:
a container;
a cathode forming a hollow cylinder and having a cathode outer surface adjacent an inner surface of the container and a cathode inner surface defining an interior portion of the cathode;
an anode positioned within an interior portion of the cathode and formed of one or more materials including an active material comprising zinc, wherein the anode defines an anode outer surface and a central portion;
a separator disposed between the anode outer surface and the cathode inner surface;
a current collector; and
an electrolyte;
wherein the anode comprises two or more discrete regions,
wherein the two or more discrete regions comprise a first anode portion that is characterized by consistent first anode characteristic therein and is adjacent to a current collector, and a second anode portion that is characterized by consistent second anode characteristic therein and is separated from the current collector by the first anode portion;
wherein each of the first anode characteristic and the second anode characteristic define an active material density and at least one of an active material particle size, an active material concentration, an active material composition, an active material surface roughness, or an active material porosity within the first anode portion and the second anode portion respectively;
wherein the active material density and the at least one of an active material particle size, an active material concentration, an active material composition, an active material surface roughness, or an active material porosity defined by the first anode characteristic are different from the active material density and the corresponding at least one of an active material particle size, an active material concentration, an active material composition, an active material surface roughness, or an active material porosity defined by the second anode characteristic; and
wherein a part of the first anode portion is intermixed with a part of the second anode portion such that the part of the first anode portion is in contact with the part of the second anode portion.

2. The primary alkaline electrochemical cell of claim 1 , wherein the first anode portion comprises the central portion of the anode and the second anode portion is positioned between the anode outer surface and the first anode portion.

3. The primary alkaline electrochemical cell of claim 1 , wherein the first anode characteristic and the second anode characteristic define a difference in an average particle size of an active material between the central portion of the anode and the anode outer surface.

4. The primary alkaline electrochemical cell of claim 2 , wherein the first anode material composition comprises an active material having a first average particle size and the second anode material composition comprises an active material having a second average particle size, wherein the first average particle size is different from the second average particle size.

5. The primary alkaline electrochemical cell of claim 4 , wherein the first average particle size is smaller than the second average particle size.

6. The primary alkaline electrochemical cell of claim 2 , wherein at least one of the first anode material or the second anode material comprises a surfactant, and wherein the first anode portion comprises a first concentration of the surfactant and the second anode portion comprises a second concentration of the surfactant, wherein the first concentration of the surfactant is different from the second concentration of the surfactant.

7. The primary alkaline electrochemical cell of claim 1 , wherein the first concentration of the surfactant is lower than the second concentration of the surfactant.

8. The primary alkaline electrochemical cell of claim 1 , wherein the first anode characteristic and the second anode characteristic define a difference in an active material alloy between the central portion of the anode and the anode outer surface.

9. The primary alkaline electrochemical cell of claim 8 , wherein the difference in the active material alloy is defined between a first active material alloy in the first anode portion and a second active material alloy in the second anode portion located adjacent the anode outer surface.

10. The primary alkaline electrochemical cell of claim 1 , wherein the first anode characteristic and the second anode characteristic define a difference in an active material concentration between the central portion of the anode and the anode outer surface.

11. The primary alkaline electrochemical cell of claim 1 , wherein at least one of the first anode portion or the second anode portion comprises a surfactant, and wherein the first anode characteristic and the second anode characteristic define a concentration difference of surfactant between the central portion of the anode and the anode outer surface.

12. The primary alkaline electrochemical cell of claim 1 , wherein the first anode portion and the second anode portion collectively define a continuous anode formed of at least the first anode characteristic and the second anode characteristic.

13. The primary alkaline electrochemical cell of claim 1 , wherein the first anode portion and the second anode portion are concentrically defined such that the second anode portion circumferentially encloses the first anode portion.

14. A method of forming primary alkaline electrochemical cell, the method comprising:
providing a container;
forming a cathode within the container, wherein the cathode is a hollow cylinder and defining a cathode outer surface positioned adjacent an interior surface of the container and a cathode interior surface defining an inner portion of the cathode;
positioning a separator within the inner portion of the cathode; and
forming an anode comprising a zinc active material and defining an anode outer surface and an anode central portion, the anode comprising two or more discrete regions,
wherein the separator is disposed between the anode outer surface and the cathode inner surface,
wherein the two or more discrete regions comprise a first anode portion that is characterized by consistent first anode characteristic therein and is adjacent to a current collector, and a second anode portion that is characterized by consistent second anode characteristic therein and is separated from the current collector by the first anode portion,
wherein each of the first anode characteristic and the second anode characteristic define an active material density and at least one of an active material particle size, an active material concentration, an active material composition, an active material surface roughness, or an active material porosity within the first anode portion and the second anode portion respectively; and
wherein the first anode characteristic is different than the second anode characteristic, and a part of the first anode portion is intermixed with a part of the second anode portion such that the part of the first anode portion is in contact with the part of the second anode portion.

15. The method of claim 14 , wherein forming the first anode portion comprises extruding a first anode composition having a first average active material particle size into the inner portion of the cathode; and
forming the second anode portion comprises extruding a second anode composition having a second average active material particle size into the central portion of the anode, wherein the second average active material particle size is smaller than the first average active m

Assignees

• Energizer Brands Llc

Inventors

• Huang Weiwei

Classifications

• H01M6/045

  characterised by aqueous electrolyte · CPC title

• H01M4/364 Primary

  as mixtures · CPC title

• H01M4/244

  Zinc electrodes · CPC title

• H01M6/085 Primary

  of the reversed type, i.e. anode in the centre · CPC title

• H01M4/9041

  Metals or alloys (H01M4/92 takes precedence) · CPC title