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EP-4212311-B1 - POUCH SEALING APPARATUS

EP4212311B1EP 4212311 B1EP4212311 B1EP 4212311B1EP-4212311-B1

Inventors

  • SEO, JA YOUNG
  • KIM, DAE HONG
  • OH, SAE YOUNG

Dates

Publication Date
20260506
Application Date
20220706

Claims (7)

  1. A pouch sealing apparatus configured to seal a pouch for batteries, the pouch including an upper pouch (11) and a lower pouch (12), the pouch being configured to receive an electrode assembly and an electrolytic solution, the pouch sealing apparatus comprising: a mounting unit (500) configured to seat a pouch receiving portion (110) thereon; a press roller (300) configured to move the electrolytic solution into the pouch receiving portion (110) while the press roller (300) rolls from open ends of the upper pouch (11) and the lower pouch (12) toward the pouch receiving portion (110); and a sealing tool (200) configured to seal parts of the upper pouch (11) and the lower pouch (12) to be sealed, wherein the press roller (300) is configured to fuse the upper pouch (11) and the lower pouch (12) in contact with each other by a heating portion (303) added to a part of the roller (300) while rolling, wherein the heating portion of at least one of the upper press roller (310) and the lower press roller (320) is configured such that a temperature thereof is increased up to 250°C, and the upper press roller (310) and the lower press roller (320) are spaced apart from each other by a predetermined distance, characterized in that the upper press roller (310) is located at upper ends of a pair of upper rails (410), the upper rails (410) being horizontally spaced apart from each other by a predetermined distance, and in that the lower press roller (320) is located at upper ends of a pair of lower rails (420), the lower rails (420) being horizontally spaced apart from each other by a predetermined distance, wherein the pair of upper rails (410) and the pair of lower rails (420) are located so as to correspond to each other up and down, and wherein the upper press roller (310) and the lower press roller (320) horizontally roll on the pair of upper rails (410) and the pair of lower rails (420), respectively.
  2. The pouch sealing apparatus according to claim 1, wherein the heating portion of at least one of the upper press roller (310) and the lower press roller (320) is configured such that a temperature thereof is increased up to 250°C, and the upper press roller (310) and the lower press roller (320) are spaced apart from each other by a predetermined distance.
  3. The pouch sealing apparatus according to claim 1, wherein a vertical distance between the pair of upper rails (410) and the pair of lower rails (420) is configured to adjust a distance between the upper press roller (310) and the lower press roller (300).
  4. The pouch sealing apparatus according to claim 1, wherein a distance between the pair of upper rails (410) and the pair of lower rails (420) is configured to be gradually reduced along a direction toward the electrode assembly.
  5. A pouch sealing method to seal a pouch for secondary batteries comprising an upper pouch (11) and a lower pouch (12), the pouch being configured to receive an electrode assembly and an electrolytic solution, the pouch sealing method comprising: (s1) horizontally locating the upper pouch (11) and the lower pouch (12) having the electrode assembly and the electrolytic solution received therein on a mounting unit (500) and disposing a gas pocket portion (120) of the pouch between a pair of rail units (410, 420), the pair of rail units (410, 420) being vertically spaced apart from each other; (s2) bringing the gas pocket portions (120) into tight contact with each other while moving a pair of press rollers (300) on the pair of rail units (410, 420) from an end of the gas pocket portion (120) of the pouch in a direction toward the electrode assembly; (s3) moving the pair of press rollers (300) in a direction away from the electrode assembly, so as to space the pair of press rollers (300) apart from the electrode assembly by a predetermined distance; and (s4) sealing the upper pouch (11) and the lower pouch (12) between the press rollers (300) and the electrode assembly using a sealing unit (200).
  6. The pouch sealing method according to claim 5, wherein, in step (s2), a temperature of each of the press rollers (300) is increased to bring the gas pocket portions (120) of the pouch into tight contact with each other.
  7. The pouch sealing method according to claim 5, wherein, in step (s2), a distance between the pair of rail units (410, 420) is adjusted to adjust a distance between the pair of press rollers (300).

Description

[Technical Field] This application claims the benefit of priority to Korean Patent Application No. 2021-0089407 filed on July 8, 2021. The present invention relates to a pouch sealing apparatus. More particularly, the present invention relates to a pouch sealing apparatus capable of easily performing sealing at a predetermined position of a pouch to be sealed while preventing leakage of an electrolytic solution out of a gas pocket portion. [Background Art] Secondary batteries may be classified depending on the structure of an electrode assembly including a positive electrode, a separator, and a negative electrode. Typically, the electrode assembly may be a jelly-roll type (wound type) electrode assembly, which is configured to have a structure in which long sheet type positive electrodes and long sheet type negative electrodes are wound in the state in which separators are interposed therebetween, a stacked type electrode assembly, which is configured to have a structure in which a plurality of positive electrodes and a plurality of negative electrodes each cut to a predetermined size are sequentially stacked in the state in which separators are interposed therebetween, or a stacked and folded type electrode assembly, which is configured to have a structure in which bi-cells or mono-cells, each of which is configured such that positive electrodes and negative electrodes each having a predetermined size are stacked in the state in which separators are interposed therebetween, are wound using a separation film. Secondary batteries may be classified into a cylindrical battery, a prismatic battery, and a pouch-shaped battery depending on the shape thereof. Thereamong, the pouch-shaped battery is manufactured using a pouch sheathing member constituted by a multilayered film including a metal layer (foil) and synthetic resin layers formed on an upper surface and a lower surface of the metal layer by coating, and therefore the weight of the pouch-shaped battery is remarkably reduced, compared to the cylindrical battery or the prismatic battery, which uses a metal can, whereby there are advantages in that it is possible to reduce the weight of the battery and to modify the battery into various forms. In general, the pouch sheathing member is constituted by a lower sheathing member configured to receive an electrode assembly and an upper sheathing member configured to seal an upper part of the lower sheathing member. The electrode assembly is received in a receiving portion of the lower sheathing member, an edge of the receiving portion of the lower sheathing member and an edge of the upper sheathing member corresponding thereto are brought into tight contact with each other, parts of the tight contact portions are thermally fused, an electrolytic solution is introduced into the pouch sheathing member, and the remaining parts of the tight contact portions are sealed, whereby a secondary battery is temporarily assembled. In an activation process, the secondary battery is loaded into a predetermined jig and the secondary battery is charged and discharged under conditions necessary for activation in order to achieve smooth current conduction. For a secondary battery, a process of activating a positive electrode active material and an activation process for creating a stable solid electrolyte interface (SEI) at a negative electrode must be essentially performed first during a first cycle due to characteristics thereof. A large amount of gas is generated in the secondary battery cell as the result of such activation processes. Subsequently, the generated gas is removed through an open or incised discharge port, and the gas discharge portion is thermally fused again so as to be sealed. A process of discharging the gas from the secondary battery as described above is generally referred to as a degassing process. After the degassing process, sealing is performed to complete the secondary battery. While the gas generated in the secondary battery moves to a gas pocket portion, some of the electrolytic solution remains in a connection portion between the secondary battery and the gas pocket portion, and the force of sealing at the connection portion is greatly reduced by the electrolytic solution that remains in the connection portion. Some electrolytic solution moves to the gas pocket portion. Since the pouch-shaped secondary battery is easily deformed, it is difficult to accurately set a sealing datum. The pouch-shaped secondary battery is less deformed when the pouch-shaped secondary battery is laid flat than when the pouch-shaped secondary battery is stood. As shown in FIG. 1, therefore, a pouch-shaped secondary battery is inserted into a sealing apparatus in the state in which the pouch-shaped secondary battery is laid flat, and sealing is performed by pressing of the sealing apparatus. An upper pouch 11 and a lower pouch 12 are inserted between an upper sealing tool 21 and a lower sealing tool 22, and the upper sealing t