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KR-20260067881-A - FUSE TAB AND SECONDARY BATTERY INCLUDING THE SAME

KR20260067881AKR 20260067881 AKR20260067881 AKR 20260067881AKR-20260067881-A

Abstract

The present disclosure relates to a fuse tab and a secondary battery including the same. According to one embodiment of the present disclosure for solving a technical problem, the fuse tab comprises a pair of first metal foils, a second metal foil disposed between the first metal foils, a wire disposed on the first metal foils and the second metal foils and electrically connecting the first metal foils, and an insulating member insulating between the first metal foils and the second metal foils and between the wire and the second metal foils, wherein the material of the first metal foils is different from the material of the second metal foils, the material of the wire is different from the material of the second metal foils, and the coefficient of thermal expansion (CTE) of the second metal foils may be greater than the coefficient of thermal expansion of the wires.

Inventors

  • 김대규
  • 서광수
  • 서근호
  • 김신중
  • 박종준

Assignees

  • 삼성에스디아이 주식회사

Dates

Publication Date
20260513
Application Date
20241106

Claims (20)

  1. A pair of first metal foils; A second metal foil disposed between the first metal foils; A wire electrically connecting the first metal foil and disposed on the first metal foil and the second metal foil; and An insulating member that insulates between the first metal foil and the second metal foil, and between the wire and the second metal foil. Includes, The material of the first metal foil is different from the material of the second metal foil, and The material of the above wire is different from the material of the above second metal foil, and A fuse tab in which the coefficient of thermal expansion (CTE) of the second metal foil is greater than the coefficient of thermal expansion of the wire.
  2. In paragraph 1, A fuse tab, wherein the wire is arranged along the longitudinal direction of the fuse tab and is joined to the first metal foil at both ends along the longitudinal direction of the wire.
  3. In paragraph 1, A fuse tab in which, when the current flowing along the wire is greater than a critical value, the second metal foil thermally expands in the longitudinal direction of the fuse tab, thereby cutting the wire.
  4. In paragraph 1, A fuse tab whose width of the wire is smaller than the width of the fuse tab.
  5. In paragraph 2, The above wire includes a first connecting portion, a second connecting portion, and a connecting portion connecting the first connecting portion and the second connecting portion, and The first coupling portion and the second coupling portion are coupled to the first metal foil, and the connecting portion is disposed on the second metal foil. A fuse tab, the width of the above connection portion being smaller than the width of either the first coupling portion or the second coupling portion.
  6. In paragraph 1, The above wire includes a first wire and a second wire having different widths, and The width of the second wire is smaller than the width of the first wire, and A fuse tab in which the first wire and the second wire are arranged alternately, and both ends of the wire in the longitudinal direction are terminated by the first wire.
  7. In paragraph 1, The insulating member comprises a first insulating member attached between the first metal foil and the second metal foil, and a second insulating member attached between the wire and the second metal foil. A fuse tab in which the width of the second insulating member is greater than the width of the wire.
  8. In paragraph 1, The insulating member comprises a first insulating member coated between the first metal foil and the second metal foil, and a second insulating member coated to surround the wire. The second insulating member is a fuse tab that wraps around the circumference of a wire placed on the second metal foil.
  9. In paragraph 1, It further includes a third metal foil coupled to the lower end of the second metal foil, and A fuse tab in which the thermal expansion coefficient of the third metal foil is greater than the thermal expansion coefficient of the second metal foil.
  10. In Paragraph 9, A fuse tab in which, when the current flowing along the wire is above a critical value, the third metal foil thermally expands in the longitudinal direction of the fuse tab, thereby cutting the wire.
  11. 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 above electrode assembly and having one end open; A cap assembly coupled to an open end of the above-mentioned 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 inserted in the middle of the first lead tab above Includes, The above fuse tab is, A pair of first metal foils; A second metal foil disposed between the first metal foils; A wire electrically connecting the first metal foil and disposed on the first metal foil and the second metal foil; and An insulating member that insulates between the first metal foil and the second metal foil, and between the wire and the second metal foil. Includes, The material of the first metal foil is different from the material of the second metal foil, and The material of the above wire is different from the material of the above second metal foil, and A secondary battery in which the coefficient of thermal expansion of the second metal foil is greater than the coefficient of thermal expansion of the wire.
  12. In Paragraph 11, A secondary battery, wherein the wire is arranged along the longitudinal direction of the fuse tab and is coupled to the first metal foil at both ends in the longitudinal direction of the wire.
  13. In Paragraph 11, A secondary battery in which, when the current flowing along the wire is above a critical value, the second metal foil thermally expands in the longitudinal direction of the fuse tab, causing the wire to be cut.
  14. In Paragraph 11, The first lead tab is bent and seated on the upper side of the electrode assembly, and The above fuse tab is a secondary battery located on the electrode assembly.
  15. In Paragraph 14, The above first lead tab further includes an insulating plate disposed between the portion seated on the upper side of the electrode assembly and the electrode assembly, A secondary battery, wherein the end of the first lead tab is connected to the bottom of the cap assembly.
  16. In Paragraph 13, A secondary battery in which, when the current flowing along the wire and the first metal foil is greater than a critical value, the second metal foil thermally expands in the longitudinal direction of the fuse tab due to heat transferred from the wire or the first metal foil.
  17. In Paragraph 16, The second metal foil above is a secondary battery that thermally expands in the longitudinal direction of the fuse tab at 120°C to 400°C.
  18. In Paragraph 11, The above first metal foil comprises any one of aluminum, stainless steel, iron, or a combination thereof, in a secondary battery.
  19. In Paragraph 11, The second metal foil comprises any one of zinc, lead, magnesium, or a combination thereof, in a secondary battery.
  20. In Paragraph 11, The above secondary battery is a cylindrical secondary battery.

Description

Fuse tab and secondary battery including the same The present disclosure relates to a fuse tab and a secondary battery including the same. Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries in hybrid and electric vehicles. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case housing the assembly, and electrode terminals connected to the electrode assembly. Secondary batteries are equipped with various protection devices that detect and cut off overcurrents when they occur inside the battery. Commonly used protection devices are components that function as fuses, which cut off the circuit when the current exceeds a certain limit to prevent overheating and damage to the battery. These can be composed of metal conductors, and if an overcurrent flows, the conductor melts to cut off the current, thereby protecting the battery. Alternatively, a Positive Temperature Coefficient (PTC) element can be used as a component that performs the function of a fuse. A PTC element interrupts the flow of current by rapidly increasing its resistance when the temperature or current rises abnormally high. Another example is the Battery Management System (BMS) used in high-capacity batteries for electric vehicles or large electronic devices. This system can ensure the safety of the battery by detecting and regulating overcurrent and temperature changes in real time. However, due to the recent trend of increasing size of lead tabs or electrode tabs connected to electrode assemblies, there is a growing demand for fuse functions to be implemented within the lead tabs or electrode tabs themselves. The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is an exploded perspective view schematically illustrating a part of a secondary battery according to one embodiment of the present disclosure. FIG. 2 is a cross-sectional view of a secondary battery before the cap assembly is assembled according to one embodiment of the present disclosure. FIG. 3 is a schematic top view of a fuse tab according to one embodiment of the present disclosure. FIG. 4 is a diagram showing the positions of insulating members according to some embodiments in FIG. 3. FIG. 5 is a diagram showing the fuse operation process of a fuse tab according to one embodiment of the present disclosure. FIG. 6 is a schematic top view of a fuse tab according to some embodiments of the present disclosure. FIG. 7 is a schematic top view of a fuse tab according to one embodiment of the present disclosure. FIG. 8 is a schematic top view of a fuse tab according to one embodiment of the present disclosure. FIG. 9 is a schematic cross-sectional view of a short-circuiting tab according to one embodiment of the present disclosure. Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application. Additionally, as used herein, “comprise, include” and/or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and/or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and/or groups. Additionally, to