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EP-4243177-B1 - BATTERY CELL AND BATTERY MODULE COMPRISING SAME

EP4243177B1EP 4243177 B1EP4243177 B1EP 4243177B1EP-4243177-B1

Inventors

  • SONG, DAE-WOONG
  • KIM, SANG-HUN
  • KANG, Min-Hyeong
  • YU, Hyung-Kyun
  • LIM, Hun-Hee
  • Hwang, Soo-Ji

Dates

Publication Date
20260513
Application Date
20220706

Claims (15)

  1. A battery cell (100), comprising: a battery case (200) having an accommodation portion (210) in which an electrode assembly (110) is mounted, and a sealing portion (250) formed by sealing an outer periphery thereof; an electrode lead (300) electrically connected to an electrode tab (150) included in the electrode assembly (110) and protruding out of the battery case (200) via the sealing portion (250); and a lead film (400) located at a portion corresponding to the sealing portion (250) in at least one of an upper portion and a lower portion of the electrode lead (300), characterized in that a gas discharge guiding unit (450) is inserted in the lead film (400), the battery case (200) includes a cover portion (270) extending from the sealing portion (250), and the cover portion (270) is located on the lead film (400) and protrudes in an outer direction of the battery case (200).
  2. The battery cell (100) according to claim 1, wherein the cover portion (270) is located on the gas discharge guiding unit (450).
  3. The battery cell (100) according to claim 2, wherein based on a direction perpendicular to the protruding direction of the electrode lead (300), a length of the cover portion (270) is equal to or greater than a length of the gas discharge guiding unit (450).
  4. The battery cell (100) according to claim 3, wherein based on the direction perpendicular to the protruding direction of the electrode lead (300), the length of the cover portion (270) is equal to or smaller than a length of the lead film (400).
  5. The battery cell (100) according to claim 1, wherein based on the protruding direction of the electrode lead (300), an end of the cover portion (270) is located outer than an end of the lead film (400).
  6. The battery cell (100) according to claim 5, wherein based on the protruding direction of the electrode lead (300), an end of the electrode lead (300) is located outer than the end of the cover portion (270).
  7. The battery cell (100) according to claim 5, wherein the cover portion (270) is bent in a direction away from the lead film (400) based on the sealing portion (250).
  8. The battery cell (100) according to claim 1, wherein the gas discharge guiding unit (450) extends along the protruding direction of the electrode lead (300), and an end of the gas discharge guiding unit (450) adjacent to an outer side of the battery case (200) is surrounded with the lead film (400).
  9. The battery cell (100) according to claim 8, wherein an end of the gas discharge guiding unit (450) adjacent to an inner side of the battery case (200) is exposed inside the battery case (200).
  10. The battery cell (100) according to claim 1, wherein a gas discharge path is formed at an interface between the gas discharge guiding unit (450) and the lead film (400).
  11. The battery cell (100) according to claim 10, wherein an adhesive force between the gas discharge guiding unit (450) and the lead film (400) is smaller than an adhesive force between the lead film (400) and the electrode lead (300) or an adhesive force between the lead film (400) and the sealing portion (250).
  12. The battery cell (100) according to claim 11, wherein the gas discharge guiding unit (450) is a film layer made of at least one of polyimide and polyethylene terephthalate.
  13. The battery cell (100) according to claim 11, wherein the gas discharge guiding unit (450) is a coating layer made of liquid resin.
  14. The battery cell (100) according to claim 1, wherein the gas discharge guiding unit (450) is located on the electrode lead (300), and an adhesive layer (470) is formed between the gas discharge guiding unit (450) and the electrode lead (300).
  15. The battery cell (100) according to claim 14, wherein an adhesive force between the gas discharge guiding unit (450) and the lead film (400) is smaller than at least one of an adhesive force between the adhesive layer (470) and the gas discharge guiding unit (450) and an adhesive force between the adhesive layer (470) and the electrode lead (300).

Description

TECHNICAL FIELD The present disclosure relates to a battery cell and a battery module including the same, and more particularly, to a battery cell improved in insulating performance and gas discharge performance. BACKGROUND ART As technology development and demand for mobile devices increase, the demand for secondary batteries as an energy source is rapidly increasing. In particular, secondary batteries are of great interest as energy sources not only for mobile devices such as mobile phones, digital cameras, notebooks and wearable devices, but also for power devices such as electric bicycles, electric vehicles and hybrid electric vehicles. Depending on the shape of a battery case, these secondary batteries are classified into a cylindrical battery and a prismatic battery in which an electrode assembly is included in a cylindrical or prismatic metal can, and a pouch-type battery in which the electrode assembly is included in a pouch-type case of an aluminum laminate sheet. Here, the electrode assembly included in the battery case is a power element including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, and capable of charging and discharging, and is classified into a jelly-roll type in which long sheet-type positive and negative electrodes coated with an active material are wound with a separator being interposed therebetween, and a stack type in which a plurality of positive and negative electrodes are sequentially stacked with a separator being interposed therebetween. Among them, in particular, a pouch-type battery in which a stack-type or stack/folding-type electrode assembly is included in a pouch-type battery case made of an aluminum laminate sheet is being used more and more due to low manufacturing cost, small weight, and easy modification. FIG. 1 is a top view showing a conventional battery cell. FIG. 2 is a cross-sectional view, taken along the axis a-a' of FIG. 1. Referring to FIGS. 1 and 2, a conventional battery cell 10 includes a battery case 20 having an accommodation portion 21 in which an electrode assembly 11 is mounted, and a sealing portion 25 formed by sealing an outer periphery thereof. In addition, the battery cell 10 includes an electrode lead 30 electrically connected to an electrode tab 15 included in the electrode assembly 11 and protruding out of the battery case 20 via the sealing portion 25, and a lead film 40 is located between upper and lower portions of the electrode lead 30 and the sealing portion 25. However, as the energy density of the battery cell increases in recent years, there is a problem that the amount of gas generated inside the battery cell also increases. In the case of the conventional battery cell 10, a component capable of discharging the gas generated inside the battery cell is not included, so a venting may occur to burst the battery case 20 due to gas generation in long-term storage. In addition, moisture may penetrate into the battery cell damaged by the venting, which may cause side reactions, and there is a problem that battery performance deteriorates and additional gas is generated. Accordingly, there is an increasing need to develop a battery cell with improved external emission of gas generated inside the battery cell. Documents KR 101 904 587 B1, KR 2013/0065288 A, KN 101 531 271 B1, KR 101 520 148 B1 and KR 2009/0065587 A are about venting gas from battery cells. DISCLOSURE Technical Problem The present disclosure is directed to providing a battery cell improved in insulating performance and gas discharge performance, and a battery module including the same. The object to be solved by the present disclosure is not limited to the above-mentioned object, and the objects not mentioned here may be clearly understood by those skilled in the art from this specification and the accompanying drawings. Technical Solution To this end, the invention relates to a battery cell according to claim 1. The battery cell according to the invention may present one or more features of dependent claims 2 to 15. Advantageous Effects According to the embodiments, the present disclosure provides a battery cell including a sealing portion from which the battery case extends, and a cover portion positioned on a lead film, and a battery module including the same, so that insulation performance and gas discharge performance may be improved. Specifically, according to one aspect of the present disclosure, a gas discharge path may be formed at the interface between the gas discharge guiding unit and the lead film, so that the gas in the battery cell may be effectively discharged to the outside, while securing a relatively easy manufacturing process. According to another aspect of the present disclosure, since the cover portion may be located outer than the end of the lead film, the insulating performance for the end surface of the end of the cover portion may be improved. Even when a crack occ