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EP-4199237-B1 - SECONDARY BATTERY

EP4199237B1EP 4199237 B1EP4199237 B1EP 4199237B1EP-4199237-B1

Inventors

  • LEE, HYUN SOO

Dates

Publication Date
20260506
Application Date
20221102

Claims (11)

  1. A secondary battery (100) comprising: an electrode assembly (110) having a first electrode tab (111a) and a second electrode tab (112a) exposed to opposite sides, respectively, of the electrode assembly (110); a first current collector (120) coupled to the first electrode tab (111a) of the electrode assembly (110); a case (160) accommodating the electrode assembly (110) and the first current collector (120) and having the opposite sides opened; a first cap plate (171) sealing an opening (161) of one side, from among the opposite sides, of the case (160); and a first terminal (130) coupled to the first current collector (120) and exposed to the outside of the first cap plate (171), wherein the first current collector (120) includes a first main plate (121) on which a multi-layered metal thin film (121z) is overlapped characterized in that the first current collector (120) includes a first sub-plate (122) surrounding both ends of the first main plate (121) in a longitudinal direction, respectively.
  2. The secondary battery (100) of claim 1, wherein in the first current collector (120), a first sub-plate (122) of one side is in contact with and welded to the first electrode tab (111a), and a first sub-plate (122) of the other side is in contact with and welded to the first terminal (130).
  3. The secondary battery (100) of claims 1 or 2, wherein the first current collector (120) comprises: a connection part (120a) formed of the first main plate (121); a first tab coupling part (120b) extending outwardly from one end of the connection part (120a), comprising the first main plate (121) and the first sub-plate (122) surrounding the first main plate (121), and coupled to the first electrode tab (111a); and a first terminal coupling part (120c) extending outwardly from an other end of the connection part (120a), comprising the first main plate (121) and the first sub-plate (122) surrounding the first main plate (121), and coupled to the first terminal (130).
  4. The secondary battery (100) of claim 3, wherein in the first current collector (120), a surface on which the first tab coupling part (120b) is in contact with and welded to the first electrode tab (111a) is the same as a surface on which the first terminal coupling part (120c) is in contact with and welded to the first terminal (130), and the connection part (120a) is bent at least once.
  5. The secondary battery (100) of any of the preceding claims, wherein a thickness of the first sub-plate (122) is 2 to 5 times the thickness of a metal thin film (121z) of the first main plate (121).
  6. The secondary battery (100) of any of the preceding claims, wherein the first main plate (121) is compressed in a state in which 4 to 10 sheets of a metal thin film (121z) of 0.05 mm to 0.2 mm are overlapped.
  7. The secondary battery (100) of any of the preceding claims, wherein the first terminal (130) comprises: a first inner terminal plate (131) inside the first cap plate (171); a first outer terminal plate (133) outside the first cap plate (171); and a first terminal pillar (132) coupled to the first inner terminal plate (131) and the first cap plate (171) from an inside, passing through the first cap plate (171), and coupled to the first outer terminal plate (133) from the outside of the first cap plate (171).
  8. The secondary battery (100) of claim 7, wherein in the first current collector (120), the first sub-plate (122) is coupled to one surface of the first inner terminal plate (131) by welding.
  9. The secondary battery (100) of any of the preceding claims, further comprising: a second current collect or (140) coupled to the second electrode tab (112a) of the electrode assembly (110); a second cap plate (181) sealing an opening (162) of the other side of the case (160); and a second terminal (150) coupled to the second current collector (140) and exposed to the outside of the second cap plate (181).
  10. The secondary battery (100) of claim 9, wherein the second current collector (140) comprises: a second main plate on which a multi-layered metal thin film is overlapped; and a second sub-plate surrounding both ends of the second main plate in the longitudinal direction, respectively.
  11. The secondary battery (100) of any of the preceding claims, wherein a thickness of the first sub-plate (122) is 0.1 mm or more.

Description

BACKGROUND 1. Field Aspects of some embodiments of the present disclosure relate to a secondary battery. 2. Description of the Related Art A secondary battery is a power storage system that provides relatively high energy density for storing electrical energy in the form of chemical energy. Compared to non-rechargeable primary batteries, secondary batteries are rechargeable and are widely used in electronic devices (e.g., portable electronic devices) such as smartphones, cellular phones, laptops, and tablet PCs. Recently, in order to prevent or reduce environmental pollution, interest in electric vehicles has increased, and high-capacity secondary batteries are being adopted for use in electric vehicles. Such secondary batteries may generally have characteristics such as relatively high density, relatively high output, and relatively high stability. For example, document US 2012/094172 A1 discloses a battery comprising a housing made by a metal or a metal alloy; a battery core in the housing; an electrolyte in the housing; a cover assembly having a positive terminal electrically connected with the positive plate and a negative terminal electrically connected with the negative plate; and a protection to prevent the housing from being corroded by the electrolyte. 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 Aspects of some embodiments of the present disclosure include a secondary battery which is entirely made of a multi-layered metal thin film to increase the overall cross-sectional area, thereby improving a heat generation property, and facilitating bending. In addition, embodiments according to the present disclosure include a secondary battery that may be capable of preventing or reducing damage during welding by wrapping a region of a current collector, which is connected to a terminal and an electrode assembly, with a thicker metal than a metal thin film. These and other aspects and characteristics of embodiments according to the present disclosure will be described in more detail or will be apparent from the following description of some embodiments of the present disclosure. The invention is set out in the appended set of claims. A secondary battery of the present disclosure includes an electrode assembly having a first electrode tab and a second electrode tab exposed to both sides, respectively, a first current collector coupled to the first electrode tab of the electrode assembly, a case accommodating the electrode assembly and the first collector and having both sides opened, a first cap plate sealing an opening of one side of the case, and a first terminal coupled to the first current collector and exposed, in particular partially exposed, to the outside of the first cap plate, wherein the first current collector includes a first main plate on which the multi-layered metal thin film is overlapped, and a first sub-plate surrounding both ends of the first main plate in the longitudinal direction, respectively. In particular, the outside of the first cap plate may correspond to the outside of the secondary battery. According to some embodiments, in the first current collector, a first sub-plate of one side may be in contact with and welded to the first electrode tab, and a first sub-plate of the other side may be in contact with and welded to the first terminal. According to some embodiments, the first current collector may include a connection part formed of the first main plate, a first tab coupling part extending outwardly from one end of the connection part, comprising the first main plate and the first sub-plate surrounding the first main plate, and coupled to the first electrode tab, and a first terminal coupling part extending outwardly from the other end of the connection part, comprising the first main plate and the first sub-plate surrounding the first main plate, and coupled to the first terminal. According to some embodiments, in the first current collector, a surface on which the first tab coupling part is in contact with and welded to the first electrode tab may be the same as a surface on which the first terminal coupling part is in contact with and welded to the first terminal, and the connection part may be bent at least once. According to some embodiments, the thickness of the first sub-plate may be 2 to 5 times the thickness of a metal thin film of the first main plate. According to some embodiments, the first main plate may be compressed in a state in which 4 to 10 sheets of the metal thin film of 0.05-0.2 mm are overlapped. According to some embodiments, the first terminal may include a first inner terminal plate positioned inside the first cap plate, a first outer terminal plate positioned outside the first cap plate, and a first terminal pillar coupled to the first inner terminal plate and the first cap pl