Button-type secondary battery

Patent metadata

Field	Value
Publication number	US-12489133-B2
Application number	US-202117908488-A
Country	US
Kind code	B2
Filing date	Aug 13, 2021
Priority date	Sep 16, 2020
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

A button-type secondary battery includes an electrode assembly; a lower can into which the electrode assembly is disposed; and an upper can configured to cover an opening of an upper end of the lower can. A beading part recessed inward is disposed at an upper portion of the lower can. The upper end of the lower can disposed above the beading part has a bent shape and configured to surround an edge end of the upper can so that the upper can and the lower can are coupled to each other.

First claim

The invention claimed is:

1 . A button-type secondary battery comprising:
an electrode assembly; a lower can into which the electrode assembly is disposed; an upper can configured to cover an opening of an upper end of the lower can, and a vent unit disposed below the upper can, the vent unit including a vent body, a vent outer edge extending outward from an end of the vent body, and a rupture notch between the vent body and the vent outer edge, wherein the vent outer edge is in contact with a bottom surface of an edge end of the upper can, wherein a beading part recessed inward is disposed at an upper portion of the lower can, wherein the upper end of the lower can disposed above the beading part has a bent shape and configured to surround the edge end of the upper can and the vent outer edge so that the upper can and the lower can are coupled to each other, wherein a first collection space is defined above the vent unit and below a bottom surface of the upper can, and a second collection space is defined below the vent unit and above the electrode assembly, the vent unit dividing the first collection space from the second collection space, wherein the rupture notch is configured to be ruptured when a gas in the second collection space exceeds a predetermined pressure, wherein gas cannot move from the second collection space to the first collection space in an unruptured state of the vent unit, and gas can move from the second collection space to the first collection space in a ruptured state of the vent unit, and wherein, in the ruptured state of the vent unit, gas is prevented from leaking to an outside of the button-type secondary battery.

2 . The button-type secondary battery of claim 1 , wherein an insulator is interposed between the edge end of the upper can and the bent portion of the upper end of the lower can, and
wherein the insulator includes a polybutylene terephthalate (PBT) material.

3 . The button-type secondary battery of claim 1 , wherein the upper can has a circular shape in a plan view and has a shape in which a central portion thereof further protrudes upward more than the edge end of the upper end so that the edge end and the central portion of the upper can are stepped with respect to each other.

4 . The button-type secondary battery of claim 1 , wherein a center hole is defined in a center of the electrode assembly, and
wherein a center pin is disposed in the center hole to fully fill the center hole.

5 . The button-type secondary battery of claim 1 , further comprising an electrode tab configured to connect an electrode of the electrode assembly to the upper can,
wherein the electrode tab has one end connected to the electrode of the electrode assembly, and wherein the electrode tab has the other end connected to a bottom surface of the upper can in a C-shape.

6 . The button-type secondary battery of claim 1 , wherein the vent body comprises a rupture notch having a recessed groove shape in an outer edge portion thereof.

7 . The button-type secondary battery of claim 1 , further comprising an electrode tab configured to connect an electrode of the electrode assembly to the vent unit,
wherein the electrode tab has one end connected to the electrode of the electrode assembly, and wherein the electrode tab has the other end connected to a bottom surface of the vent body in a C-shape.

8 . The button-type secondary battery of claim 7 , wherein a point at which the other end of the electrode tab and the bottom surface of the vent body are bonded to each other is disposed inside the rupture notch.

9 . The button-type secondary battery of claim 8 , wherein the rupture notch is configured to be ruptured when a gas generated in the lower can exceeds a predetermined pressure.

10 . The button-type secondary battery of claim 9 , wherein the vent body and the vent outer edge are configured to be separated from each other, and a flow of current between the electrode assembly and the upper can is configured to be blocked when the rupture notch is ruptured.

11 . The button-type secondary battery of claim 9 , wherein the collection space is configured so that the internal gas moves from the second collection space to the first collection space when the rupture notch is ruptured.

12 . The button-type secondary battery of claim 1 , wherein a center hole is defined in a central portion of the electrode assembly, wherein a center pin is disposed in the center hole, and wherein the center pin includes a porous center pin in which a plurality of internal center pin spaces are formed.

13 . The button-type secondary battery of claim 1 , wherein the button-type secondary battery has a diameter greater than a height thereof.

14 . The button-type secondary battery of claim 1 , wherein, in the ruptured state of the vent unit, the vent body and the vent outer edge are separated from each other.

15 . The button-type secondary battery of claim 1 , wherein the vent outer edge is in electrical contact with the bottom surface of an edge end of the upper can, and an electrode of the electrode assembly is electrically connected to the vent body so that current flow between the electrode assembly and the upper can is possible in the unruptured state of the vent unit, and
wherein, in the ruptured state of the vent unit, the vent body and the vent outer edge are separated from each other so that current flow between the electrode assembly and the upper can is blocked.

Assignees

• Lg Energy Solution Ltd

Inventors

• Kim Min Gyu
• Lee Yong Gon
• Lee Je Jun
• Lim Jae Won
• Min Geon Woo
• Cho Min Su
• Sung Joo Hwan
• Chae Sang Hak

Classifications

• H01M10/0431

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

• H01M50/153

  for button or coin cells · CPC title

• H01M50/583

  in response to current, e.g. fuses · CPC title

• H01M50/3425

  in the form of rupturable membranes or weakened parts, e.g. pierced with the aid of a sharp member · CPC title

• H01M50/578

  in response to pressure · CPC title