Electrode Having Improved Electrode Tab Welding Characteristics and Secondary Battery Comprising the Same

Patent metadata

Field	Value
Publication number	US-2020185690-A1
Application number	US-201816615305-A
Country	US
Kind code	A1
Filing date	Jul 12, 2018
Priority date	Sep 8, 2017
Publication date	Jun 11, 2020
Grant date	—

Abstract

Disclosed herein are an electrode having improved electrode tab welding characteristics configured such that one or more non-coated electrode tabs are provided for a plurality of stacked electrodes having the same polarity in order to maintain welding safety in the case in which the number of electrode layers that are stacked is increased in order to achieve high output and capacity, and a secondary battery including the same. Consequently, it is possible to prevent a plurality of electrode tabs from being cut at the time of welding the electrode tabs. In addition, the lower end of an electrode lead that is welded to non-coated electrode tabs provided for a plurality of stacked electrodes having the same polarity is punched so as to correspond to the non-coated electrode tabs. Consequently, it is possible to improve flexibility for a step formed in the secondary battery electrode.

First claim

1 . A secondary battery electrode assembly, comprising:
a plurality of negative electrodes alternatingly interleaved with a plurality of positive electrodes in a vertical stack, with separators disposed between adjacent ones of the electrodes; and a plurality of non-coated electrode tabs, each of the tabs extending from a respective one of the electrodes having a first same polarity, the plurality of non-coated electrode tabs being arranged in first and second spaced-apart vertical stacks so as to alternately overlap each other, such that the electrode tabs in the first vertical stack extend from a first odd-numbered half of the electrodes having the first same polarity, and the electrode tabs in the second vertical stack extend from a second even-numbered half of the electrodes having the first same polarity.

2 . The secondary battery electrode assembly according to claim 1 , further comprising an electrode lead, the electrode tabs in the first vertical stack being coupled to the electrode lead at a first location, the electrode tabs in the second vertical stack being coupled to the electrode lead at a second location, the first and second locations being spaced apart from each other by a predetermined distance.

3 . The secondary battery electrode assembly according to claim 2 , wherein the predetermined distance is less than or equal to a width of the electrode lead.

4 . The secondary battery electrode assembly according to claim 1 , wherein a first total thickness of the electrode tabs in the first vertical stack and a second total thickness of the electrode tabs in the second vertical stack are each equal to half of a third total thickness of all of the electrode tabs having the first same polarity.

5 . (canceled)

6 . The secondary battery electrode assembly according to claim 2 , wherein a lower end of the electrode lead that is welded to the electrode tabs is punched so that the first and second locations are at first and second portions of the lower end of the electrode lead that are separated from one another by the predetermined distance.

7 . The secondary battery electrode assembly according to claim 6 , wherein a punched length of each of the first and second portions of the lower end of the electrode lead extends from a lower edge of the electrode lead to a central region of the electrode lead that is configured to be affixed to a sealing part of a pouch-shaped battery case by an insulating tape.

8 . An apparatus for welding the secondary battery electrode assembly according to claim 1 , wherein the apparatus is configured to weld the electrode tabs in the first and second vertical stacks using a sonotrode horn, the sonotrode horn comprising:
a vibration-applying plate; and a horn pattern region having a protrusion-type unit pitch pattern disposed on the vibration-applying plate, and wherein a radius of curvature of a side surface of the protrusion-type unit pitch pattern disposed at an outer edge of the horn pattern region is directly proportional to a number of the non-coated electrode tabs in each of the first and second vertical stacks.

9 . An apparatus for welding the secondary battery electrode assembly according to claim 1 , wherein the apparatus is configured to weld the electrode tabs in the first and second vertical stacks using a sonotrode horn, the sonotrode horn comprising:
a vibration-applying plate; and a horn pattern region having a protrusion-type unit pitch pattern disposed on the vibration-applying plate, and wherein a tip sharpness of the protrusion-type unit pitch pattern disposed at an outer edge of the horn pattern region is inversely proportional to a number of the non-coated electrode tabs in each of the first and second vertical stacks.

10 . The apparatus according to claim 8 , wherein, in the case in which the protrusion-type unit pitch pattern comes into contact with the non-coated electrode tabs and/or an electrode lead for welding, an inscribed radius of the protrusion-type unit pitch pattern that is formed together with the non-coated electrode tabs and/or the electrode lead is directly proportional to the number of the non-coated electrode tabs in each of the first and second vertical stacks.

11 . The apparatus according to claim 8 , wherein the protrusion-type unit pitch pattern is a hemispherical protruding pattern having a curvature formed at a side wall surface thereof.

12 . A secondary battery comprising the secondary battery electrode assembly according to claim 1 , wherein the secondary battery is a jelly-roll type battery or a stacked type battery.

13 . A device comprising a secondary battery comprising the secondary battery electrode assembly according to any claim 1 .

14 . The device according to claim 13 , wherein the device is selected from a group consisting of: an electric device, an electric vehicle, a hybrid electric vehicle, and a power storage apparatus.

15 . The apparatus according to claim 9 , wherein, in the case in which the protrusion-type unit pitch pattern comes into contact with the non-coated electrode tabs and/or an electrode lead for welding, an inscribed radius of the protrusion-type unit pitch pattern that is formed together with the non-coated electrode tabs and/or the electrode lead is directly proportional to the number of the non-coated electrode tabs in each of the first and second vertical stacks.

16 . The apparatus according to claim 9 , wherein the protrusion-type unit pitch pattern is a hemispherical protruding pattern having a curvature formed at a side wall surface thereof.

Assignees

• Lg Chemical Ltd

Inventors

• Kim Tae Gon
• Seo Seung Yeop
• Shin Seong Kyun
• Lee Nam Kyu
• Choi Ha Neuol

Classifications

• B23K20/10 Primary

  making use of vibrations, e.g. ultrasonic welding · CPC title

• H01M50/536

  characterised by the method of fixing the leads to the electrodes, e.g. by welding · CPC title

• H01M50/538 Primary

  Connection of several leads or tabs of wound or folded electrode stacks · CPC title

• H01M50/533 Primary

  characterised by the shape of the leads or tabs · CPC title

• Y02E60/10

  Energy storage using batteries · CPC title