US-20260128482-A1 - FUSE TAB AND SECONDARY BATTERY INCLUDING THE FUSE TAB

US20260128482A1US 20260128482 A1US20260128482 A1US 20260128482A1US-20260128482-A1

Abstract

The present disclosure relates to a fuse tab and a secondary battery including the same. A fuse tab includes a pair of first metal foils, a second metal foil disposed located between the first metal foils, a wire electrically connecting the first metal foils and disposed located on the first metal foils and the second metal foil, and an insulating member insulating the first metal foils and the second metal foil and insulating the wire and the second metal foil, wherein a material of the first metal foils is different from a material of the second metal foil, a material of the wire is different from the material of the second metal foil, and a coefficient of thermal expansion (CTE) of the second metal foil is larger than a coefficient of thermal expansion of the wire.

Inventors

Dae Kyu Kim
Kwangsoo Seo
Geunho Seo
Shinjung KIM
Jongjun PARK

Assignees

SAMSUNG SDI CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20250721
Priority Date: 20241106

Claims (20)

1 . A fuse tab comprising: a pair of first metal foils; a second metal foil located between the first metal foils; a wire electrically connecting the first metal foils and located on the first metal foils and the second metal foil; and an insulating member insulating between the first metal foils and the second metal foil and insulating between the wire and the second metal foil, wherein a material of the first metal foils is different from a material of the second metal foil, wherein a material of the wire is different from the material of the second metal foil, and wherein a coefficient of thermal expansion of the second metal foil is greater than a coefficient of thermal expansion of the wire.
2 . The fuse tab as claimed in claim 1 , wherein the wire is located along a longitudinal direction of the fuse tab and is coupled to the first metal foils at opposite ends of the wire in a longitudinal direction.
3 . The fuse tab as claimed in claim 1 , wherein the fust tab is configured such that when a current flowing along the wire is greater than or equal to a threshold value, the second metal foil thermally expands in a longitudinal direction of the fuse tab to thereby break the wire.
4 . The fuse tab as claimed in claim 1 , wherein a width of the wire is less than a width of the fuse tab.
5 . The fuse tab as claimed in claim 2 , wherein the wire comprises a first coupling portion, a second coupling portion, and a connecting portion connecting the first coupling portion and the second coupling portion, wherein the first coupling portion and the second coupling portion are coupled to the first metal foils, and the connecting portion is provided on the second metal foil, and wherein a width of the connecting portion is less than a width of the first coupling portion or the second coupling portion.
6 . The fuse tab as claimed in claim 1 , wherein the wire includes first wires and second wires, with widths of the first wires being different than widths of the second wires, wherein a width of the second wire is less than a width of the first wire, and wherein the first wires and the second wires alternate in a longitudinal direction of the wire, and one of the first wires are provided at ends of the wire in the longitudinal direction.
7 . The fuse tab as claimed in claim 1 , wherein the insulating member comprises first insulating members positioned between the first metal foil and the second metal foil, and a second insulating member positioned between the wire and the second metal foil, and wherein a width of the second insulating member is greater than a width of the wire.
8 . The fuse tab as claimed in claim 1 , wherein the insulating member comprises first insulating members coated between the first metal foils and the second metal foil, and a second insulating member coated around the wire, and wherein the second insulating member surrounds a circumference of the wire that is located on the second metal foil.
9 . The fuse tab as claimed in claim 1 , further comprising: a third metal foil coupled to a lower end of the second metal foil, wherein a coefficient of thermal expansion of the third metal foil is greater than a coefficient of thermal expansion of the second metal foil.
10 . The fuse tab as claimed in claim 9 , wherein the fuse tab is configured such that when a current flowing along the wire is greater than or equal to a threshold value, the third metal foil thermally expands in a longitudinal direction of the fuse tab to thereby break the wire.
11 . A secondary battery comprising: an electrode assembly comprising a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode; a can accommodating the electrode assembly and having an open end; a cap assembly sealing the open end of the can; a first lead tab connected to the first electrode of the electrode assembly and coupled to the cap assembly; a second lead tab connected to the second electrode of the electrode assembly; and a fuse tab provided in the middle of the first lead tab, wherein the fuse tab comprises: a pair of first metal foils, a second metal foil located between the first metal foils, a wire electrically connecting the first metal foils and located on the first metal foils and the second metal foil, and an insulating member insulating between the first metal foils and the second metal foil and insulating between the wire and the second metal foil, wherein a material of the first metal foils is different from a material of the second metal foil, wherein a material of the wire is different from a material of the second metal foil, and wherein a coefficient of thermal expansion of the second metal foil is greater than a coefficient of thermal expansion of the wire.
12 . The secondary battery as claimed in claim 11 , wherein the wire is located along a longitudinal direction of the fuse tab and is coupled to the first metal foils at opposite ends of the wire in a longitudinal direction.
13 . The secondary battery as claimed in claim 11 , wherein the fust tab is configured such that when a current flowing along the wire is greater than a threshold value, the second metal foil thermally expands in a length direction of the fuse tab to thereby cut the wire.
14 . The secondary battery as claimed in claim 11 , wherein the first lead tab is bent and mounted on an upper side of the electrode assembly, and the fuse tab is positioned on the electrode assembly.
15 . The secondary battery as claimed in claim 14 , further comprising: an insulating plate located between a portion of the first lead tab mounted to the upper side of the electrode assembly and the electrode assembly, wherein an end of the first lead tab is connected to a lower end of the cap assembly.
16 . The secondary battery as claimed in claim 13 , wherein the fuse tab is configured such that when a current flowing along the wire and the first metal foils is greater than a threshold value, the second metal foil thermally expands in a longitudinal direction of the fuse tab due to heat transferred from the wire and the first metal foils.
17 . The secondary battery as claimed in claim 16 , wherein the second metal foil is configured to expand in the longitudinal direction of the fuse tab at a temperature of 120° C. to 400° C.
18 . The secondary battery as claimed in claim 11 , wherein the first metal foils comprise aluminum, stainless steel, iron, or a combination thereof.
19 . The secondary battery as claimed in claim 11 , wherein the second metal foil comprises zinc, lead, magnesium, or a combination thereof.
20 . The secondary battery as claimed in claim 11 , wherein the secondary battery is a cylindrical battery.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This present application claims priority to and the benefit under 35 U.S.C. § 119(a)-(d) of Korean Patent Application No. 10-2024-0156542, filed on Nov. 6, 2024, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. BACKGROUND 1. Field The present disclosure relates to a fuse tab and a secondary battery including the fuse tab. 2. Description of Related Art Unlike primary batteries that are not designed to be (re) charged, secondary (or rechargeable) batteries are batteries that are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable, small electronic devices, such as smart phones, feature phones, notebook computers, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for driving motors in hybrid vehicles and electric vehicles and for storing power (e.g., home and/or utility scale power storage). A secondary battery generally includes an electrode assembly composed of a positive electrode and a negative electrode, a case accommodating the same, and electrode terminals connected to the electrode assembly. Secondary batteries have various protective devices that detect and cut off an overcurrent occurring inside the battery. Commonly used protective devices include components that perform a fuse function of cutting off a circuit when a current exceeds a certain limit to prevent overheating and damage to the battery. The protective device may include a metal conductor. When an excessive current flows, the conductor melts and the current is cut off. As a result, damage to the battery may be prevented. Alternatively, a positive temperature coefficient (PTC) element may be used as a component performing the fuse function. The PTC element cuts off a flow of the current by rapidly increasing a resistance when a temperature or a current becomes abnormally high. Alternatively, a battery management system (BMS) for a high-capacity battery used in an electric vehicle or a large electronic device may detect and adjust an overcurrent and a temperature change of a battery in real time. As the size of a lead tab or an electrode tab connected to an electrode assembly has increased, it is desirable for the fuse function to be implemented in the lead tab or the electrode tab itself. The above information disclosed in this Background section is for enhancement of understanding of the background of the present disclosure, and therefore, it may contain information that does not constitute related (or prior) art. SUMMARY An object of the present disclosure is to provide a fuse tab and a secondary battery including the fuse tab that may solve the above-described problems. However, the technical problem to be solved by the present disclosure is not limited to the above problems, and other problems not mentioned herein, and aspects and features of the present disclosure that would address such problems, will be clearly understood by those skilled in the art from the description of the present disclosure below. According to one or more embodiments of the present disclosure, a fuse tab includes a pair of first metal foils, a second metal foil disposed located between the first metal foils, a wire electrically connecting the first metal foils and disposed located on the first metal foils and the second metal foil, and an insulating member insulating between the first metal foils and the second metal foil and insulating between the wire and the second metal foil, wherein a material of the first metal foils is different from a material of the second metal foil, a material of the wire is different from the material of the second metal foil, and a coefficient of thermal expansion of the second metal foil is greater than a coefficient of thermal expansion of the wire. In an embodiment, the wire may be located along a longitudinal direction of the fuse tab, and may be coupled to the first metal foils at opposite ends of the wire in a longitudinal direction. In an embodiment, the fust tab is configured such that when a current flowing along the wire is greater than or equal to a threshold value, the second metal foil may thermally expand in a longitudinal direction of the fuse tab to thereby break the wire. In an embodiment, a width of the wire may be less than a width of the fuse tab. In an embodiment, the wire may include a first coupling portion, a second coupling portion, and a connecting portion connecting the first coupling portion and the second coupling portion, the first coupling portion and the second coupling portion are coupled to the first metal foils, and the connecting portion is provided on the second metal foil, and a width of the connecting portion is less than a width of the first coupling portion or the second coupling portion. In an embodiment, the wire may include first wires and second wires with widths of the first wires being