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CN-122003732-A - Electrode, method for manufacturing the same, and slot die for coating active material

CN122003732ACN 122003732 ACN122003732 ACN 122003732ACN-122003732-A

Abstract

The present disclosure relates to a slot die for coating an active material layer on a foil, an electrode manufacturing method for manufacturing an electrode using the slot die, and an electrode manufactured using the slot die. According to the present disclosure, the slot die is configured to move in a width direction relative to the foil.

Inventors

  • Yin Taijian

Assignees

  • 株式会社LG新能源

Dates

Publication Date
20260508
Application Date
20250709
Priority Date
20240729

Claims (16)

  1. 1. A method of manufacturing an electrode, comprising: A coating step of coating active material layers by applying active material slurries to both surfaces of a foil having a predetermined first width which is unwound and advanced from a foil roll, each active material layer being coated on an area of the foil except an uncoated area having a predetermined second width which extends along one end portion in a width direction of the foil, Wherein in the coating step, the coating of the active material layer is performed by a slot die that discharges the active material slurry while relatively moving in a width direction with respect to the foil.
  2. 2. The electrode manufacturing method according to claim 1, wherein the active material slurry is discharged when the slot-type die is relatively moved in a first width direction, and the active material slurry is not discharged when the slot-type die is relatively moved in a second width direction.
  3. 3. The electrode manufacturing method according to claim 1, wherein the active material slurry is discharged when the slot-die moves in both of a first width direction and a second width direction.
  4. 4. The electrode manufacturing method according to claim 1, further comprising: A cutting step of cutting the foil along cutting lines extending in the width direction at first length intervals after the coating step to form electrodes, Wherein the discharge slot of the slot die extends a second length equal to or greater than the first length.
  5. 5. The electrode manufacturing method according to claim 4, wherein the second length is equal to or greater than twice the first length.
  6. 6. The electrode manufacturing method according to claim 4, wherein in the cutting step, the cutting line is located in a region continuously coated with the active material layer on both sides in a length direction thereof.
  7. 7. The electrode manufacturing method according to claim 1, further comprising: a rolling step of rolling and flattening the foil in a thickness direction of the foil after the coating step.
  8. 8. The electrode manufacturing method according to claim 7, wherein in the coating step, an overlapping portion in which the active material layer is coated in two or more layers is formed in at least a partial region extending in the width direction on both surfaces of the foil.
  9. 9. The electrode manufacturing method according to claim 8, wherein the overlapping portion is formed by overlapping a first coating portion formed by the slot die and an immediately subsequent second coating portion with each other by a predetermined length.
  10. 10. The electrode manufacturing method according to claim 7, wherein in the coating step, in at least a partial region extending in the width direction on both surfaces of the foil, the active material layer is formed to be coated as a ridge thicker than the remaining portion.
  11. 11. The electrode manufacturing method according to claim 10, wherein the ridge portion is formed in a region corresponding to an end portion in a longitudinal direction of a discharge groove of the groove-type die.
  12. 12. The electrode manufacturing method according to claim 7, wherein in the coating step, a ridge portion in which the active material layer is coated thicker than the remaining portion is formed in at least any one of both end portions in the width direction of the active material layer along the length direction.
  13. 13. The electrode manufacturing method according to claim 12, wherein the ridge portion is formed along an end portion of the active material layer on the uncoated region side.
  14. 14. A slot die for coating an active material layer by applying active material paste to both surfaces of a foil having a predetermined width which is unwound and advanced from a foil roll, the slot die comprising: A discharge groove from which the active material slurry is discharged, and which extends in a length direction, Wherein the slot die is configured to discharge the active material slurry while relatively moving in a width direction with respect to the foil.
  15. 15. The slot die according to claim 14, wherein, at both ends in the length direction of the discharge slot, an expanded portion having a larger width than the remaining portion is formed.
  16. 16. An electrode, comprising: A foil; An active material layer coated on both surfaces of the foil; An uncoated region extending in a length direction along one side end in a width direction of the foil and having an active material layer uncoated thereon, and An insulating layer including a covering portion covering the active material layer and an attaching portion attached to the uncoated region, Wherein the cover portion includes an arch portion having an arch shape that bulges toward the uncoated area.

Description

Electrode, method for manufacturing the same, and slot die for coating active material Technical Field The present application claims the benefit of priority based on korean patent application No. 10-2024-0100538 filed on the 7 th month 29 of 2024, and the entire contents of the disclosure of the document of this patent application are included as part of the present specification. The present disclosure relates to a slot die for coating an active material layer on a foil, an electrode manufacturing method for manufacturing an electrode using the slot die, and an electrode manufactured using the slot die. Background Secondary batteries having high application capability and electrical characteristics such as high energy density according to product groups are generally applied not only to portable devices but also to Electric Vehicles (EVs) or Hybrid Electric Vehicles (HEVs) driven by electric drive sources. These secondary batteries are attracting attention as new energy sources for enhancing the eco-friendliness and energy efficiency not only because they can greatly reduce the major advantage of the use of fossil fuels but also because no by-products are generated during the use of energy. Examples of various secondary batteries that are currently in wide use include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel hydrogen batteries, nickel zinc batteries, and the like. Such unit secondary battery cells, that is, unit battery cells, have an operating voltage in the range of about 2.5V to 4.5V. Therefore, when an output voltage higher than this is required, the battery pack can be configured by connecting a plurality of battery cells in series. Further, the battery pack may be configured by connecting a plurality of battery cells in parallel based on the charge and discharge capacity required for the battery pack. Accordingly, the number of battery cells included in the battery pack and the configuration of the electrical connection thereof may be differently set based on the desired output voltage and/or charge and discharge capacity. On the other hand, the known types of unit secondary battery cells include cylindrical battery cells, prismatic battery cells, and pouch-type battery cells. Among these battery cells, the pouch-type battery cell generally includes a stacked electrode assembly in which a plurality of electrodes cut to have a constant width are stacked with a separator interposed therebetween. Each electrode includes a foil made of metal and active material layers coated on both surfaces of the foil. Fig. 1 shows a state in which a groove-type mold coats an active material layer on a foil, and fig. 2 shows an electrode formed by cutting the foil of fig. 1. Referring to these drawings, the electrode 1 is formed by coating active material slurry discharged from a slot die 2 onto both surfaces of a foil 10 which is unwound from a foil roll 100 and continuously supplied to coat an active material layer 11, and then cutting the coated foil at predetermined intervals in the length direction. At this time, the active material layer 11 is not coated on the entire surface of the foil 10, and an uncoated region 12 on which the active material slurry is not coated is formed along one end portion in the width direction of the foil. The uncoated region 12 is then subjected to a grooving process to form a tab for electrically connecting each electrode 1 with a terminal. Fig. 3 is an enlarged cross-sectional view showing an end portion beside an uncoated region of an active material layer in the electrode of fig. 2. Meanwhile, referring back to fig. 1, due to the flow of the active material slurry, sliding portions 110 may be formed in regions of the active material layer 11 corresponding to both ends in the length direction of the slot die 2. This sliding phenomenon is a phenomenon in which the thickness of the active material layer 11 becomes gradually thinner toward the end thereof, so that the coating surface area and thickness of the active material layer 11 are not uniform. Such non-uniformity negatively affects the charge and discharge efficiency and stability of the entire battery. Further, in general, the active material layer 11 coated on the foil 10 as described above is flattened by a rolling step, but the sliding portion 110 formed to have a smaller thickness than that of the remaining portion cannot be appropriately pressurized during the rolling process and cannot be flattened together with the remaining portion. Further, when the coated surface area and thickness of the active material layer 11 are not uniform, the adhesion between the separator and the electrode 1, which is generated by the binder contained in the active material slurry and the binder coated on the surface of the separator, may be weakened. Because of this, the fixing force between the electrode 1 and the separator may be weakened, and the structural stability of the electrode assembly may