Rechargeable hearing aid battery with slotted grommet

Patent metadata

Field	Value
Publication number	US-11949060-B2
Application number	US-201916567478-A
Country	US
Kind code	B2
Filing date	Sep 11, 2019
Priority date	Sep 11, 2018
Publication date	Apr 2, 2024
Grant date	Apr 2, 2024

Abstract

A rechargeable hearing aid battery includes a stack of active materials forming a core, a two-part casing including an inner casing and an outer casing, and a grommet. The grommet includes an opening through which a conductive tab extends. The conductive tab is configured to electrically connect an electrode of the core to one of the outer casing and the inner casing. The grommet is configured to insulate a portion of the tab from the core and to insulate the core from one of the outer casing and the inner casing. Furthermore, the grommet is configured to separate the inner casing from the outer casing and to seal a gap formed between the inner and outer casing.

First claim

What is claimed is:

1. A button cell battery comprising:
a casing comprising:
an inner casing;
an outer casing that at least partially surrounds the inner casing, wherein together the outer casing and the inner casing define an internal volume;

a core disposed in the internal volume, the core comprising:
a first electrode;
a second electrode;
at least one separator layer disposed between the first electrode and the second electrode; and
a first tab having a first end and a second end, wherein the first end is attached to one of the first electrode and the second electrode and the second end is attached to one of the outer casing and the inner casing; and

a grommet disposed at least partially between the inner casing and the outer casing, the grommet comprising an opening disposed in a bottom wall of the grommet where the bottom wall of the grommet is solid other than the opening, wherein the opening is a rectangular slot positioned a distance from a central axis of the grommet, wherein the core is separated from one of the outer casing and the inner casing by the bottom wall of the grommet, and wherein the first tab extends through the opening;
wherein the grommet further includes a sidewall attached to and extending upwards relative to an outer periphery of the bottom wall of the grommet;
wherein the grommet bottom wall is disposed between a lower surface of the outer casing and a lower surface of the inner casing, and the grommet sidewall is disposed between an outer surface of a sidewall of the inner casing and an inner surface of a sidewall of the outer casing; and
wherein the grommet sidewall is arranged to seal the inner casing and the outer casing, the grommet sidewall is arranged to insulate the inner casing from the outer casing, and the grommet bottom wall is arranged to insulate the core from the outer casing.

2. The button cell battery of claim 1 , wherein the first tab is welded to one of the outer casing and the inner casing.

3. The button cell battery of claim 1 , wherein the grommet is configured to seal a gap between the inner casing and the outer casing.

4. The button cell battery of claim 1 , the core further comprising a mandrel, wherein the first electrode, the second electrode, a first separator layer, and a second separator layer are arranged in a stack, wherein the first separator layer and the second separator layer are disposed on opposite sides of the first electrode or second electrode, wherein the stack is wound in a spiral configuration around the mandrel.

5. The button cell battery of claim 4 , wherein a height of the mandrel parallel to an axis of the mandrel is greater than a height of the stack parallel to the axis of the mandrel.

6. The button cell battery of claim 4 , wherein a height of each of the first separator layer and the second separator layer parallel to an axis of the mandrel is greater than a height of both the first electrode and the second electrode parallel to the axis of the mandrel.

7. The button cell battery of claim 4 , wherein the first electrode is welded to the mandrel before winding the stack about the mandrel.

8. The button cell battery of claim 7 , wherein the first electrode is an anode of the button cell battery and the second electrode is a cathode of the button cell battery.

9. The button cell battery of claim 7 , wherein the first electrode is a cathode of the button cell battery and the second electrode is an anode of the button cell battery.

10. A method of assembly for a button cell battery, the button cell battery comprising an active core, an inner casing defining an upper cavity, an outer casing defining a lower cavity, and a grommet that is configured to separate the active core from the outer casing, the grommet comprising an opening disposed in a bottom wall of the grommet where the bottom wall of the grommet is solid other than the opening, and a sidewall attached to an extending upwards relative to an outer periphery of the bottom wall of the grommet, the method comprising:
inserting the active core into one of the upper cavity and the lower cavity, the active core comprising a stack, the stack comprising a first electrode and a second electrode;
inserting a tab through the opening in the grommet, wherein the opening is a rectangular slot positioned a distance from a central axis of the grommet, and wherein a first end of the tab is attached to one of the first electrode and the second electrode;
fitting the inner casing to the outer casing, wherein the grommet separates the inner casing from the outer casing;
sealing the inner casing and the outer casing with the grommet sidewall;
insulating the inner casing from the outer casing with the grommet sidewall; and
insulating the core from the outer casing with the grommet bottom wall.

11. The method of claim 10 , further comprising folding an upper edge of the outer casing over the grommet and the inner casing.

12. The method of claim 10 , the stack further comprising a first separator layer, and a second separator layer, wherein the first separator layer and the second separator layer are disposed on opposite sides of the first electrode, the method further comprising:
welding the first electrode to a mandrel; and
winding the stack in a spiral configuration around the mandrel to form the active core.

13. The method of claim 12 , further comprising welding the mandrel to the inner casing.

14. The method of claim 12 , further comprising welding the mandrel to the outer casing.

15. A button cell battery comprising:
a casing comprising:
an inner casing; and
an outer casing that at least partially surrounds the inner casing, wherein together the inner casing and the outer casing define an internal volume;
a core disposed in the internal volume;
a first tab configured to electrically couple a portion of the core to one of the inner casing and the outer casing; and
a grommet disposed within the internal volume between the core and at least one of the outer casing and the inner casing;
wherein the grommet comprises an opening disposed in a bottom wall of the grommet where the bottom wall of the grommet is solid other than the opening, wherein the opening is a rectangular slot positioned a distance from a central axis of the grommet, and wherein the first tab extends through the opening;
wherein the grommet includes a sidewall attached to and extending upwards relative to an outer periphery of the bottom wall of the grommet, and wherein:
the grommet sidewall is arranged to seal the inner casing and the outer casing,
the grommet sidewall is configured to electrically insulate the outer casing from the inner casing,
the grommet bottom wall is configured to electrically insulate the core from one of the outer casing and the inner casing, and
the grommet is configured to electrically insulate a portion of the first tab from the core.

Assignees

• Energizer Brands Llc

Inventors

• Sabrowsky Benjamin
• Syvertsen Marc
• Imhoff Casey
• Proffit Danielle
• Karsseboom Jacob

Classifications

• H01M10/0427 Primary

  Button cells · CPC title

• H01M10/0431

  Cells with wound or folded electrodes (H01M10/045 takes precedence) · CPC title

• H01M50/109

  of button or coin shape · CPC title

• H01M50/153

  for button or coin cells · CPC title

• H01M50/181

  for button or coin cells · CPC title