EP-4737046-A1 - ULTRASONIC WELDING DEVICE AND METHOD FOR MANUFACTURING SECONDARY BATTERY USING ULTRASONIC WELDING DEVICE

EP4737046A1EP 4737046 A1EP4737046 A1EP 4737046A1EP-4737046-A1

Abstract

An ultrasonic welding device according to an embodiment of the present disclosure comprises: an anvil that supports a welding target from below; and a welding horn disposed on the welding target and having a body, at least one pair of heads provided on one end of the body, and a plurality of welding knurls provided on one-side surfaces of the heads, wherein the positions of the heads in primary welding of the welding target and the positions of the heads in secondary welding are different from each other. According to the embodiment of the present disclosure, since a welding area between substrate tabs and a welding area between a substrate tab and a lead tab do not overlap, damage such as breakage or perforation of a welding portion can be prevented. Accordingly, the adhesion between the substrate tabs, and the cutting uniformity of substrate tabs can be improved. In addition, strip terminals can be welded on the uniform surfaces of the substrate tabs, thereby improving welding quality.

Inventors

SEO, YE JIN
KIM, DONG HYUN
MOON, EUN JEONG

Assignees

Samsung SDI Co., Ltd.

Dates

Publication Date: 20260506
Application Date: 20250721

Claims (15)

An ultrasonic welding device for a secondary battery, comprising: an anvil configured to support a welding target; and a welding horn configured to be disposed on the welding target, the welding horn comprising: a body; a pair of heads disposed on one end of the body; and a plurality of welding knurls disposed on a surface of each of the pair of heads, wherein each of the pair of heads, upon primary welding of the welding target, is in a first position, wherein each of the pair of heads, upon secondary welding of the welding target, is in a second position, and wherein the first position and the second position are different from each other.
The ultrasonic welding device as claimed in claim 1, wherein each of the heads is detachable or movable from the body.
The ultrasonic welding device as claimed in claim 1 or 2, wherein a distance between each of the pair of heads in the first position is greater than that in the second position; preferably wherein each of the pair of heads includes a coupling part, and wherein the body comprises an insertion part.
The ultrasonic welding device according to one of claims 1 to 3, wherein the welding horn is provided in a pair, and each welding horn has one head; preferably wherein a distance between each welding horn in the first position is greater than that in the second position.
The ultrasonic welding device according to one of claims 1 to 4, wherein a primary welding portion and a secondary welding portion do not overlap with each other.
The ultrasonic welding device as claimed in claim 5, wherein the secondary welding portion is disposed between any two of the primary welding portion; preferably wherein the primary welding portion and the secondary welding portion are each provided in an even number.
A method for manufacturing a secondary battery using an ultrasonic welding device as claimed in one of claims 1 to 6, the method comprising: welding, using the ultrasonic welding device, a negative electrode substrate tab of a negative electrode plate of an electrode assembly of the secondary battery to a first strip terminal electrically connected to the negative electrode substrate tab, and a positive electrode substrate tab of a positive electrode plate of the electrode assembly to a second strip terminal electrically connected to the positive electrode substrate tab.
The method as claimed in claim 7, wherein the welding comprises primary welding between a plurality of the negative electrode substrate tab and between a plurality of the positive electrode substrate tab.
The method as claimed in claim 8, wherein the welding further comprises secondary welding between the primarily welded plurality of the negative electrode substrate tab and the first strip terminal and between the primarily welded plurality of the positive electrode substrate tab and the second strip terminal.
The method as claimed in claim 9, wherein the primary welding is performed on the negative electrode substrate tab and the positive electrode substrate tab.
The method according to claim 10, wherein the secondary welding is performed on the first strip terminal welded to the negative electrode substrate tab and on the second strip terminal welded to the positive electrode substrate tabs.
The method as claimed in claim 11, wherein an X-axis width of the negative electrode substrate tab and an X-axis width of the positive electrode substrate tab are each greater than an X-axis width of the first strip terminal or the second strip terminal.
The method according to one of claims 7 to 12 , wherein a primary welding portion and a secondary welding portion do not overlap with each other; preferably wherein the secondary welding portion is disposed between any two of the primary welding portion.
The method according to claim 13, wherein: the primary welding portion and the secondary welding portion are arranged at both ends in an X-axis direction of the negative electrode substrate tab and the positive electrode substrate tab; and/or any two of the primary welding portion are spaced apart from each other in a Y-axis direction of the negative electrode substrate tab and the positive electrode substrate tab.
The method as claimed in claim 14, wherein the primary welding portion and the secondary welding portion are each provided in an even number.

Description

The present application claims priority to and the benefit of Korean Patent Application No. 10-2024-0153141 filed on November 1, 2024, the entire contents of which is incorporated by reference. BACKGROUND 1. Field The present disclosure relates to an ultrasonic welding device and a method for manufacturing a secondary battery using the ultrasonic welding device. 2. Description of the Related Art Unlike a primary battery, a secondary battery may be charged and discharged. Low-capacity secondary batteries having a single battery cell packaged in the form of a pack are widely employed in small, portable electronic devices, such as smart phones, feature phones, laptop computers, digital cameras, camcorders, and the like, while large-capacity secondary batteries are widely used as power sources for driving motors in hybrid vehicles, electric vehicles, and the like, as well as batteries for power storage. The secondary battery includes an electrode assembly consisting of a positive electrode and a negative electrode, a case that accommodates the electrode assembly, and electrode terminals connected to the electrode assembly. An ultrasonic welding device can for example be used for welding between multiple substrate tabs of a secondary battery and welding between a substrate tab and a strip terminal. An ultrasonic welding device may perform welding by applying heat and pressure to a welding target while the welding target is placed on an anvil and the welding target is pressed by a welding horn in which a welding knurl protrudes. Typically, multiple substrate tabs are welded and strip terminals are then welded again, and breakage may occur at portions where welding portions overlap. The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not constitute prior art. SUMMARY Embodiments of the present disclosure provide an ultrasonic welding device capable of preventing damage or breakage of welding portions by preventing overlapping of the welding portions during ultrasonic welding, and a method for manufacturing a secondary battery using the ultrasonic welding device. However, the technical problems to be achieved in the embodiment of the disclosure are not limited to the technical problems mentioned above, and other technical problems not mentioned herein will be clearly understood from the following description by those skilled in the art to which the disclosure belongs. Embodiments of the present disclosure provide an ultrasonic welding device for a secondary battery that may include: an anvil configured to support a welding target; and a welding horn configured to be disposed on the welding target, the welding horn including: a body; a pair of heads disposed on one end of the body; and a plurality of welding knurls that may be disposed on a surface of each of the pair of heads, wherein each of the pair of heads, upon primary welding of the welding target, is in a first position, wherein each of the pair of heads, upon secondary welding of the welding target, is in a second position, and wherein the first position and the second position are different from each other. In some embodiments, each of the (pair of) heads may be detachable or movable from the body. In some embodiments, a distance between each of the pair of heads in the first position may be greater than that in the second position. In some embodiments, each of the pair of heads may include a coupling part, and wherein the body may comprise an insertion part. In some embodiments, the welding horn may be provided in a pair, and each welding horn may have one head. In some embodiments, a distance between each welding horn in the first position may be greater than that in the second position. In some embodiments, a primary welding portion and a secondary welding portion may not overlap with each other. In some embodiments, the secondary welding portion may be disposed between any two of the primary welding portion. In some embodiments, the primary welding portion and the secondary welding portion may be each provided in an even number. Embodiments of the present disclosure provide a method for manufacturing a secondary battery using an ultrasonic welding device, the method including: welding, using the ultrasonic welding device, a negative electrode substrate tab of a negative electrode plate of an electrode assembly of the secondary battery to a first strip terminal electrically connected to the negative electrode substrate tab, and a positive electrode substrate tab of a positive electrode plate of the electrode assembly to a second strip terminal electrically connected to the positive electrode substrate tab. In some embodiments, the welding may comprise primary welding between a plurality of the negative electrode substrate tab and between a plurality of the positive electrode substrate tab. In some embodiments, the welding