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KR-20260066267-A - REUSING POUCH CELL AND REUSING METHOD FOR POUCH CELL

KR20260066267AKR 20260066267 AKR20260066267 AKR 20260066267AKR-20260066267-A

Abstract

The present invention relates to a regenerative pouch cell comprising: an electrode assembly having a cathode, a separator, and an anode stacked thereon; a pouch-type case having an internal space for accommodating the electrode assembly and an electrolyte; and an extension portion extending from a part of the pouch-type case, a second sealing portion sealing at least a portion of the edge of the extension portion, and a first sealing portion sealing the edge of the pouch-type case and the edge of the extension portion excluding the second sealing portion, wherein the sealing strength of the first sealing portion is greater than the sealing strength of the second sealing portion.

Inventors

  • 이범희
  • 김의성

Assignees

  • 주식회사 엘지에너지솔루션

Dates

Publication Date
20260512
Application Date
20241104

Claims (14)

  1. An electrode assembly having a stacked cathode, a separator, and an anode; A pouch-type case comprising an internal space for accommodating the electrode assembly and the electrolyte; and It includes an extension portion extending from a part of the above pouch-type case, and It includes a second sealing portion that seals at least a portion of the edge of the extension portion, and a first sealing portion that seals the edge of the pouch-type case and the edge of the extension portion excluding the second sealing portion. A regenerated pouch cell in which the sealing strength of the first sealing portion is greater than the sealing strength of the second sealing portion.
  2. A regenerative pouch cell according to claim 1, wherein the pouch-type case and the extension part are connected to each other so that electrolyte and gas can move.
  3. A regenerative pouch cell according to claim 1, wherein the pouch-type case comprises a lower pouch and an upper pouch extending from one end of the lower pouch.
  4. A regenerated pouch cell according to claim 1, wherein the extension part is an electrolyte addition part that additionally injects an electrolyte into the internal space of the pouch-type case.
  5. A regenerated pouch cell according to claim 1, wherein the second sealing part discharges gas generated inside the pouch-type case to the outside.
  6. A regenerated pouch cell according to claim 1, wherein the sealing strength of the first sealing part is 5 kgf/15mm or more, and the sealing strength of the second sealing part is 4.5 kgf/15m or more.
  7. A regenerated pouch cell according to claim 1, wherein the sealing strength of the second sealing portion is 90% or more of the sealing strength of the first sealing portion.
  8. In claim 1, the extension portion is located at one of the corners of the pouch-type case and is a regenerated pouch cell into which the electrolyte is additionally injected.
  9. A regenerative pouch cell according to claim 1, wherein the second sealing portion seals the end located opposite to the portion connected to the pouch-type case among the edges of the extension portion, and the end of the extension portion is provided as a straight line.
  10. A step of preparing a pouch cell comprising a first sealing portion by storing an electrode assembly and an electrolyte in the internal space of a pouch-type case and sealing the edge of the pouch-type case and the edge of an extension portion extending from the pouch-type case; A step of additionally injecting the electrolyte into the internal space by drilling an additional injection hole on one side of an extension portion extended from the above pouch-type case and The method includes a second sealing step for manufacturing a regenerated pouch cell including a second sealing portion by sealing the space between the additional injection hole and the pouch-type case, and A pouch cell regeneration method in which the sealing strength of the first sealing part is greater than the sealing strength of the second sealing part.
  11. A pouch cell regeneration method according to claim 10, wherein, in the step of preparing the pouch cell, the part of the pouch-type case in contact with the extension is connected so that the gas generated from the electrolyte and the electrode assembly moves from the internal space to the extension.
  12. In claim 10, in the step of preparing the pouch cell, the first sealing part seals the edge of the pouch-type case by applying pressure of 350 kPa to 400 kPa at a temperature of 150°C to 200°C, and A pouch cell regeneration method in which the second sealing step seals the edge of the extension by applying pressure of 200 kPa to 350 kPa at a temperature of 100°C to 180°C.
  13. A pouch cell regeneration method according to claim 10, further comprising a degassing step in which gas inside the pouch-type case is discharged to the extension after the second sealing step.
  14. In item 10, the extension portion includes, based on the second sealing portion, a first portion between the second sealing portion and the pouch-type case and a second portion opposite to the first portion, and A pouch cell regeneration method further comprising the step of cutting the above-mentioned second part.

Description

Reusing Pouch Cell and Reusing Method for Pouch Cell The present invention relates to a regenerated pouch cell and a pouch cell regeneration method. Specifically, the present invention relates to a regenerated pouch cell and a pouch cell regeneration method that delays the degradation of an electrode assembly by regenerating the electrolyte retention inside the pouch cell. Generally, a secondary battery refers to a battery that can be charged and discharged, unlike a primary battery which cannot be recharged. Such secondary batteries are widely used in the field of high-tech electronic devices, such as phones, laptop computers, and camcorders. Secondary batteries can ensure stability by undergoing a stability test that measures internal short circuits by compressing one side with a press. Generally, unit cells stacked in a three-layer structure of anode/separator/cathode, or a five-layer structure of anode/separator/cathode/separator/anode, or cathode/separator/anode/separator/cathode, are assembled to form a single electrode assembly. And this electrode assembly is housed in a specific case. Secondary batteries are classified into pouch type and can type depending on the material of the case housing the electrode assembly. The pouch type houses the electrode assembly in a pouch made of a flexible polymer material with an irregular shape. The can type, on the other hand, houses the electrode assembly in a case made of a material such as metal or plastic with a uniform shape. For a pouch-type secondary battery, a stacked cell or a folded cell is inserted into the receiving portion of the pouch, and then the top and side portions of the pouch are sealed. At this time, one side of the pouch is formed as an open, unsealed section. Then, after injecting the electrolyte into the unsealed area, the front of the pouch is sealed to seal it. Pouch-type secondary batteries have a problem in that the electrolyte is consumed as charging and discharging proceeds, leading to performance degradation. FIG. 1 is a cross-sectional view illustrating a regenerated pouch cell according to one embodiment of the present invention. FIG. 2 is an exploded perspective view of a regenerated pouch cell according to one embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating the sequence of a pouch cell regeneration method according to one embodiment of the present invention. FIG. 4 is a flowchart illustrating a pouch cell regeneration method according to one embodiment of the present invention. The detailed description of the present invention is intended to fully explain the invention to those skilled in the art. Throughout the specification, when a part is described as "comprising" a certain component or "featuring" a certain structure and shape, unless specifically stated otherwise, this does not mean that other components are excluded or other structures and shapes are excluded, but rather that other components, structures, and shapes may be included. The present invention is capable of various modifications and may have various embodiments, and specific embodiments are presented and described in detail in the detailed description. However, this is not intended to limit the scope of the invention with respect to the embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention. The present invention will be described in detail below with reference to the drawings. However, the drawings are intended to illustrate the invention, and the scope of the invention is not limited by the drawings. FIG. 1 is a cross-sectional view illustrating a regenerated pouch cell (100) according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of a regenerated pouch cell (100) according to one embodiment of the present invention. The regenerative pouch cell (100) according to the present invention includes an electrode assembly (10), a pouch-type case (20), and an extension part (30). The electrode assembly (10) is a rechargeable power generation device comprising a stack of a positive electrode, a negative electrode, and a separator, and a pouch case having a space in which the stack is housed and an electrolyte is stored. Additionally, the stack may include a positive electrode tab and a negative electrode tab on one side or both sides, respectively. In one embodiment, the laminate comprises one or more anodes, cathodes, and separators, and may be laminated in the order of cathode, separator, anode, and separator. In another embodiment, the laminate may include a stack-and-fold structure in which a cathode and an anode are stacked in sequence between a separator folded in a zigzag shape. In another embodiment, the laminate can be wound after a single anode, a separator, and a cathode are laminated in sequence. The positive electrode can be formed by coating a positive active material on on