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KR-20260067442-A - POUCH SEALING DEVICE AND POUCH SEALING METHOD

KR20260067442AKR 20260067442 AKR20260067442 AKR 20260067442AKR-20260067442-A

Abstract

The present invention relates to a pouch sealing device and a pouch sealing method for sealing a pouch of a rechargeable secondary battery. A pouch sealing device according to the present invention may include: a seating portion on which a pouch cell is seated; a pair of rollers arranged to seal the terrace by applying pressure to the sealing line of the terrace of the pouch cell seated on the seating portion; a thickness measuring portion for measuring the thickness of each part of the sealing line; a calculation unit for pre-setting the spacing between the rollers to be maintained for each part of the sealing line when the pair of rollers apply pressure, so that the entire sealing line is uniformly pressed by the pair of rollers; and a moving unit for rolling the pair of rollers while maintaining the spacing set by the calculation unit for each part of the sealing line.

Inventors

  • 박성주

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260513
Application Date
20241104

Claims (11)

  1. A seating portion where the pouch cell is seated; A pair of rollers provided to seal the terrace by applying pressure to the sealing line of the terrace of the pouch cell seated on the above-mentioned seating portion; A thickness measuring unit for measuring the thickness of each part of the above sealing line; A calculation unit for pre-setting the spacing between rollers to be maintained for each part of the sealing line when the pair of rollers apply pressure, so that the entire sealing line is uniformly pressed by the pair of rollers; and A pouch sealing device comprising a moving unit that rolls and moves a pair of rollers while maintaining a set interval in the operation unit for each part of the sealing line.
  2. In claim 1, The above-mentioned seating portion is, A pouch sealing device comprising a rigid plate having a groove formed therein for seating the cup portion of the pouch cell.
  3. In claim 1, A pouch sealing device having a heating wire inside at least one of the above pair of rollers.
  4. In claim 1, The above-mentioned operation unit is, A pouch sealing device that pre-sets the vertical spacing of the pair of rollers according to the horizontal position of the pair of rollers so that the pair of rollers uniformly press each part of the sealing line.
  5. In claim 1, The above-mentioned moving unit is, A first moving member that moves each of the above pair of rollers in a vertical direction; and A pouch sealing device comprising a second moving member that moves the above pair of rollers in a horizontal direction.
  6. In claim 5, The first moving member above is, A bar extended in the vertical direction; and It includes a pair of linear motors coupled to the above bar, A pouch sealing device in which the above pair of linear motors are each coupled to the above pair of rollers to move each of the above pair of rollers in a vertical direction.
  7. In claim 6, The above second moving member is, A rail that extends horizontally; and It includes an LM guide that moves horizontally along the above rail, A pouch sealing device in which the above bar is coupled to the above LM guide and moves horizontally along the rail together with the above LM guide.
  8. In claim 1, The thickness measuring unit above is, A pouch sealing device comprising an ultrasonic sensor that measures the thickness of a sealing line through the time it takes for ultrasonic waves emitted from one side of the sealing line to be reflected back from the opposite side of the sealing line.
  9. Cell introduction step for introducing pouch cells into a pouch sealing device; A thickness measurement step for measuring the thickness of each part of the sealing line of the terrace of the above pouch cell; and The sealing step includes a pair of rollers provided in the pouch sealing device pressing the sealing line and sealing the terrace, and The above sealing step is, A first step of pre-setting the spacing between rollers to be maintained for each part of the sealing line when the pair of rollers apply pressure, so that the entire sealing line is uniformly pressed by the pair of rollers; and A pouch sealing method comprising a second step of sealing the terrace by rolling the pair of rollers while maintaining the spacing between the rollers set in the first step.
  10. In claim 9, The above cell introduction step is, A pouch sealing method comprising the step of seating the cup portion of the pouch cell in a groove formed in the rigid plate of the above pouch sealing device.
  11. In claim 9, The above thickness measurement step is, A pouch sealing method comprising the step of measuring the thickness of the sealing line through the time it takes for ultrasonic waves emitted from one side of the sealing line to be reflected back from the opposite side of the sealing line.

Description

Pouch Sealing Device and Pouch Sealing Method The present invention relates to a pouch sealing device and a pouch sealing method for sealing a pouch of a rechargeable secondary battery. Batteries that store electrical energy can generally be classified into primary and secondary batteries. Primary batteries are disposable, consumable batteries, whereas secondary batteries are rechargeable batteries manufactured using materials capable of repeating oxidation and reduction processes between the electric current and the material. In other words, when a reduction reaction is performed on the material by the electric current, the power is charged, and when an oxidation reaction is performed, the power is discharged; electricity is generated as this charging and discharging cycle is repeatedly performed. Secondary batteries can be classified into cylindrical cells, pouch cells, prismatic cells, etc., depending on their shape. Among these, pouch cells can be manufactured by housing an electrode assembly in which a positive electrode, a negative electrode, and a separator are stacked inside a pouch, and sealing the outer part of the pouch. Meanwhile, the electrolyte can be contained along with the electrode assembly inside the pouch of the pouch cell. The terrace region, which is the edge of the pouch cell housing the electrode assembly, must be sealed to receive heat and pressure; however, since the thickness of this terrace region is not uniform, it was not easy to deliver uniform heat and pressure across the entire terrace region. Specifically, electrode leads are inserted into a portion of the terrace area of the pouch cell, and this portion may be formed thicker than other portions of the terrace area. Sealing of the terrace area was performed by applying pressure to the terrace area all at once using a high-temperature jig. In this case, high pressure is applied to the portion where the electrode leads are inserted, while the portion other than where the electrode leads are inserted may be pressed weakly. Therefore, the parts of the terrace area of the pouch cell that are relatively weakly pressurized were not sufficiently sealed, resulting in leakage of the electrolyte through those parts. In addition, the parts of the terrace area of the pouch cell where the electrode leads are inserted are strongly pressurized, leading to over-sealing of those parts or damage to the electrode leads. Figure 1 is a drawing illustrating the sealing line of a pouch-type secondary battery. FIG. 2 is a right side view of a pouch sealing device according to the present invention. Figure 3 is a drawing illustrating the movement of a pair of rollers along a sealing line. Figure 4 is a diagram illustrating the vertical movement of a pair of rollers. Figure 5 is a diagram illustrating the horizontal movement of a pair of rollers. Figure 6 is a diagram illustrating the mechanism for measuring the thickness of a sealing line. FIG. 7 is a flowchart illustrating each step of the pouch sealing method according to the present invention in sequence. Figure 8 is a flowchart for explaining the sealing step in detail among the pouch sealing methods. Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments. In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification. Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Pouch sealing device FIG. 1 is a drawing for explaining the sealing line of a pouch-type secondary battery, and FIG. 2 is a right side view of a pouch sealing device according to the present invention. FIG. 3 is a drawing for explaining the movement of a pair of rollers along the sealing line. Referring to FIGS. 1 to 3, a pouch sealing device (10) according to the present invention comprises a seating portion (100) on which a pouch cell (1) is seated, a pair of rollers (210, 220) arranged to seal a terrace (2) by applying pressure to the sealing line (3) of a pouch cell (1) seated on the seating portion (100), a thickness measuring portion (300) for measurin