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EP-4224585-B1 - ELECTRODE ASSEMBLY

EP4224585B1EP 4224585 B1EP4224585 B1EP 4224585B1EP-4224585-B1

Inventors

  • KWON, MYUNG BIN

Dates

Publication Date
20260513
Application Date
20221012

Claims (8)

  1. An electrode assembly (10, 100, 200), comprising: an electrode laminate (20, 110, 210); protective blocks (120, 220) that wrap around an edge portion of the electrode laminate (20, 110, 210); and a fixing tape (30, 130) that is wound around an outer surface of the electrode laminate (20, 110, 210) and an outer surface of the protective block (120, 220) in a full width direction or a full length direction, wherein the protective block (120, 220) is made up of a first protective panel, and a second protective panel extending vertically from one longitudinal side of the first protective panel, wherein a) four protective blocks (120, 220) wrap around the edge portions of the electrode laminate (20, 110, 210) in the full length direction, and are provided at each of the edge portions in the full length direction of the electrode laminate (20, 110, 210), wherein each of the protective blocks has a separation distance from an adjacent protective block, or b) four protective blocks (120, 220) wrap around the edge portions in the full width direction of the electrode laminate (20, 110, 210) except for an electrode tab (21a, 111a, 22a, 112a), and are provided at each of the edge portions in the full width direction of the electrode laminate (20, 110, 210), wherein each of the protective blocks has a separation distance from an adjacent protective block, or c) four protective blocks (120, 220) wrap around the edge portions in the full length direction of the electrode laminate (20, 110, 210) and four protective blocks (120, 220) wrap around the edge portions in the full width direction except for the electrode tab (21a, 111a, 22a, 112a), and are provided at each of the edge portions in the full length direction and the full width direction of the electrode laminate (20, 110, 210), wherein each of the protective blocks has a separation distance from an adjacent protective block.
  2. The electrode assembly (10, 100, 200) according to claim 1, wherein the protective block (120, 220) is manufactured from at least one material selected from the group consisting of polyethylene, polypropylene, polyvinylidene difluoride, polyethylene terephthalate, polyimide, ethylene vinyl acetate, and acrylate compounds.
  3. The electrode assembly (10, 100, 200) according to claim 1, wherein the fixing tapes (30, 130) are provided at a plurality of positions, and are located to be spaced apart from each other.
  4. The electrode assembly (10, 100, 200) according to claim 1, wherein the fixing tape (30, 130) is wound around the outer surface of the electrode laminate (20, 110, 210) and the outer surface of the protective block (120, 220) by one or more turns in the full width direction.
  5. The electrode assembly according to claim 1, wherein a plurality of fixing tapes are fixed at symmetrical positions on the basis of a full width line on a midpoint in the full length direction of the electrode assembly.
  6. The electrode assembly (10, 100, 200) according to claim 1, wherein the fixing tape (30), 130) is wound around the outer surface of the electrode laminate (20, 110, 210) and the outer surface of the protective block (120, 220) by one or more turns in the full length direction.
  7. The electrode assembly according to claim 1, wherein a plurality of fixing tapes are fixed at symmetrical positions on the basis of a full length line on a midpoint in the full width direction of the electrode assembly.
  8. The electrode assembly (10, 100, 200) according to claim 1, wherein the electrode laminate (20, 110, 210) has a separator interposed between a positive electrode (111, 211) and a negative electrode (112, 212), and a form in which a length in the full length direction of the electrode laminate (20, 110, 210) is longer than a length in the full width direction orthogonal to the full length direction.

Description

[Technical Field] The present application claims the benefit of priority based on Korean Patent Application Nos. 10-2021-0134888 filed on October 12, 2021, and 10-2022-0129405 filed on October 11, 2022. The present invention relates to an electrode assembly comprising a protective block. [Background Art] With the development of portable electronic devices such as mobile phones and laptop computers, the demand for secondary batteries as an energy source thereof has increased rapidly. In recent years, the use of secondary batteries as power sources for hybrid electric vehicles (HEV) and electric vehicles (EV) has been actualized. Therefore, many studies have been conducted on secondary batteries that can fulfill various demands. In particular, the demand for lithium secondary batteries with high energy density, high discharge voltage and output are increasing. However, the lithium secondary battery has a problem of basically low safety. During the use of the secondary battery, if a defect such as short circuit occurs in a local part of battery elements, it may cause phenomena such as an internal temperature rise and gas generation, and the form of the internal elements such as electrodes may be deformed due to the temperature rise and the generated gas. Such a form deformation may accelerate the occurrence of additional short circuit, and the likelihood of battery ignition due to short circuit also increases. The lithium secondary battery includes an electrode assembly in which a positive electrode and a negative electrode each coated with a positive electrode active material and a negative electrode active material are disposed with a separator interposed therebetween, and a battery case as an external package that seals and houses the electrode assembly together with an electrolytic solution. The electrode assembly consisting of an electrode laminate having a positive electrode/separator/negative electrode structure, which constitutes the lithium secondary battery, may be classified into a jelly-roll type (wound type), a stack type (laminated type), and a stack/folding type that is a mixture form thereof. The jelly-roll type electrode assembly is manufactured by coating a metal foil used as a current collector with an electrode active material or the like, drying and pressing the metal foil, cutting it into a band shape of a desired width and length, separating the positive electrode and the negative electrode using the separator, and then, rolling it spirally. The jelly-roll type electrode assembly is suitable for a cylindrical battery. The stack type or stack/folding type electrode assembly has a structure in which positive electrode and negative electrode units are sequentially stacked with the separator interposed therebetween in the electrode laminate, and it is easy to obtain a prismatic shape. The stack type or stack/folding type lithium secondary battery can be obtained by a method in which mono cells having a positive electrode/separator/negative electrode/separator structure are stacked repeatedly or folded using a continuous separator, or a method in which the positive electrode is added above and below half cells of the separator/negative electrode/separator structure. On the other hand, in the stack type or stack/folding type lithium secondary batteries, low-voltage defective cells in which the battery exhibits voltage drop behavior higher than self-discharge rate are sometimes found. The main cause of the low-voltage failure is that corner portions of the separator are folded or torn during the assembly process, so that the positive electrode and negative electrode directly face each other and thus are electrically short-circuited. Accordingly, it is necessary to develop an electrode assembly that can solve the above problem. [Prior Art Document] Korean Patent Application No. 10-2018-0081926EP 2 416 432 A1 relates to secondary battery,EP 1 202 371 A1 relates to a flexible laminate casing,KR 1020200102261 A relates to a pouch-type secondary battery comprising deformation preventing structure,KR 1020160051647 A relates to a method for manufacturing a secondary battery and the secondary battery,KR 1020170103485 A relates to electrode assembly for electrochemical device. [Disclosure] [Technical Problem] As a result of multi-modal studies to solve the above problem, it was confirmed that a phenomenon in which the separator is folded or torn does not occur when the edge portions of the electrode laminate are surrounded with a protective block consisting of a first protective panel and a second protective panel extending vertically from one longitudinal side of the first protective panel. Accordingly, an object of the present invention is to provide an electrode assembly that does not cause separator damage. [Technical Solution] In order to achieve the above object, the present invention provides an electrode assembly as described in the attached set of claims, comprising: an electrode laminate;a pro