Pouch-shaped Secondary Battery Comprising Electrode Lead Having Asymmetrical Notch Formed Therein

Patent metadata

Field	Value
Publication number	US-2020251713-A1
Application number	US-201816482531-A
Country	US
Kind code	A1
Filing date	Jul 2, 2018
Priority date	Jul 6, 2017
Publication date	Aug 6, 2020
Grant date	—

Abstract

Disclosed herein is a pouch-shaped secondary battery including a battery case, an electrode assembly having a structure in which a positive electrode and a negative electrode are stacked in the state in which a separator is interposed therebetween, an electrode lead having an asymmetrical notch formed in a first surface of the electrode lead, the electrode lead being electrically connected to electrode tabs of the electrode assembly, the asymmetrical notch being configured to induce the rupture of the electrode lead, a lead film attached to the first surface and a second surface of the electrode lead, the lead film adhering the electrode lead to the battery case, the lead film including a first lead film located between the electrode assembly and the asymmetrical notch, and a second lead film located between the asymmetrical notch and a portion of the electrode lead that protrudes out of the battery case.

First claim

1 . A pouch-shaped secondary battery comprising:
a battery case; an electrode assembly having a structure in which a positive electrode and a negative electrode are stacked in a state in which a separator is interposed therebetween, the electrode assembly having electrode tabs, the electrode assembly being disposed inside of the battery case; an electrode lead having an asymmetrical notch formed in a first surface of the electrode lead, the electrode lead being electrically connected to the electrode tabs of the electrode assembly, the asymmetrical notch being configured to induce a rupture of the electrode lead, the electrode lead having a portion thereof that protrudes out of the battery case; and a lead film attached to the first surface and a second surface of the electrode lead, the lead film adhering the electrode lead to the battery case, the lead film comprising a first lead film located between the electrode assembly and the asymmetrical notch, and a second lead film located between the asymmetrical notch and the portion of the electrode lead that protrudes out of the battery case.

2 . The pouch-shaped secondary battery according to claim 1 , wherein the first lead film is only attached to the electrode lead at the second surface.

3 . The pouch-shaped secondary battery according to claim 1 , wherein the second lead film is attached to the first surface and the second surface of the electrode lead such that at least a portion of the second lead film attached to the first surface of the electrode lead and at least a portion of the second lead film attached to the second surface of the electrode lead overlap each other in a vertical direction perpendicular to a longitudinal direction of the electrode lead.

4 . The pouch-shaped secondary battery according to claim 1 , wherein the second lead film comprises an upper lead film, which is attached to the first surface of the electrode lead, and a lower lead film, which is attached to the second surface of the electrode lead, the upper lead film and the lower lead film having respective planar sizes that are different from each other.

5 . The pouch-shaped secondary battery according to claim 2 , wherein a size of a portion of the second lead film attached to the second surface of the electrode lead is less than a size of a portion of the second lead film attached to the first surface of the electrode lead.

6 . The pouch-shaped secondary battery according to claim 1 , wherein the asymmetrical notch is continuously formed in the electrode lead from a first edge of the first surface of the electrode lead to a second edge of the first surface of the electrode lead in a lateral direction perpendicular to a longitudinal direction of the electrode lead.

7 . The pouch-shaped secondary battery according to claim 6 , wherein a depth of a concave middle part of the asymmetrical notch is increased between the first and second edges, the depth being defined in a vertical direction perpendicular to both the lateral and longitudinal directions of the electrode lead.

8 . The pouch-shaped secondary battery according to claim 6 , wherein a width of the asymmetrical notch is increased between the first and second edges, the width being defined in the longitudinal direction of the electrode lead.

9 . The pouch-shaped secondary battery according to claim 1 , wherein a first thickness of a portion of the electrode lead in which the asymmetrical notch is formed is 10% to 90% of a second thickness of a portion of the electrode lead in which no notch is formed, the first and second thicknesses each being defined in a vertical direction perpendicular to a longitudinal direction of the electrode lead.

10 . The pouch-shaped secondary battery according to claim 7 , wherein a ratio of a minimum value to a maximum value of the depth of the concave middle part of the asymmetrical notch is between 0.1 and 0.9.

11 . The pouch-shaped secondary battery according to claim 1 , wherein the electrode lead comprises an inner electrode lead and an outer electrode lead, the first lead film being attached to the inner electrode lead, and the second lead film being attached to the outer electrode lead, the asymmetrical notch extending between the inner electrode lead and the outer electrode lead.

12 . The pouch-shaped secondary battery according to claim 11 , wherein the inner electrode lead and the outer electrode lead are configured to be attached to different respective ones of an upper part and a lower part of the battery case when the asymmetrical notch is in a ruptured state.

13 . A device comprising a pouch-shaped secondary battery according to claim 1 .

14 . A method of rupturing an electrode lead having an asymmetrical notch formed in a first surface of the electrode lead, the electrode lead coupled to a battery case of a pouch-shaped secondary battery, the electrode lead having a portion thereof that protrudes out of the battery case, the method comprising:
charging an electrode assembly of the pouch-shaped secondary battery, the electrode assembly having electrode tabs electrically connected to the electrode lead, the electrode assembly being disposed inside of the battery case; producing a gas within the battery case; expanding the outer portions of the battery case, thereby moving a first lead film apart from a second lead film, each of the first and second lead films being attached to the electrode lead, the first lead film located between the electrode assembly and the asymmetrical notch, and the second lead film located between the asymmetrical notch and the portion of the electrode lead that protrudes out of the battery case; and rupturing the asymmetrical notch, thereby interrupting a flow of current through the portion of the electrode lead that protrudes out of the battery case.

15 . The method according to claim 14 , wherein the rupturing of the asymmetrical notch separates the portion of the electrode lead that protrudes out of the battery case from a portion of the electrode lead that is coupled to the electrode tabs.

16 . The method according to claim 14 , wherein after the rupturing of the asymmetrical notch, the portion of the electrode lead that protrudes out of the battery case and the portion of the electrode lead that is coupled to the electrode tabs are attached to different respective ones of an upper part and a lower part of the battery case.

17 . The method according to claim 14 , wherein the asymmetrical notch is continuously formed in the electrode lead from a first edge of the first surface of the electrode lead to a second edge of the first surface of the electrode lead in a lateral direction perpendicular to a longitudinal direction of the electrode lead.

18 . The method according to claim 17 , wherein a depth of a concave middle part of the asymmetrical notch is increased between the first and second edges, the depth being defined in a vertical direction perpendicular to both the lateral and longitudinal directions of the electrode lead.

19 . The method according to claim 17 , wherein a width of the asymmetrical notch is increased between the first and second edges, the width being defined in the longitudinal direction of the electrode lead.

20 . The method according to claim 14 , wherein a first thickness of a portion of the electrode lead in which the asymmetrical notch is formed is 10% to 90% of a second thickness of a portion of the electrode lead in which no notch is formed, the first and second thicknesses each being defined in a vertical direction per

Assignees

• Lg Chemical Ltd

Inventors

• Park Jong Pil
• Kim Kyoung Ho
• Lee Min Woo
• Kim Sang Hun
• Kim Yong

Classifications

• H01M50/548

  on opposite sides of the cell · CPC title

• H01M50/105

  Pouches or flexible bags · CPC title

• H01M50/562 Primary

  characterised by the material · CPC title

• H01M50/574

  Devices or arrangements for the interruption of current · CPC title

• H01M50/553

  Terminals adapted for prismatic, pouch or rectangular cells · CPC title