EP-4741071-A1 - SLOT DIE COATER AND ELECTRODE FOR SECONDARY BATTERY

Abstract

A slot die coater includes a first die block on a second die block with a first slot therebetween, the second die block including a first chamber accommodating a mixture, a third die block on the second die block with a second slot therebetween, the third die block including a second chamber accommodating a slurry, a first spacer in the first slot, the first spacer including an inner region connecting the first slot to a first discharge port, the first discharge port setting a width of the mixture discharged and applied from the first discharge port, and a shielding protrusion protruding from the inner region toward the first discharge port, and a second spacer in the second slot, the second spacer including a pocket connecting the second slot to a second discharge port, and the second discharge port overlapping a part of an edge portion of the first discharge port.

Inventors

• AN, Eunjin
• KIM, SANGGI
• KIM, YONGSOO
• KWAK, JUNHYEOK
• KIM, HYUNCHUL
• KIM, Yongin
• HONG, CHAN

Assignees

• SAMSUNG SDI CO., LTD.

Dates

Publication Date

20260513

Application Date

20251028

Claims (15)

1. A slot die coater (100), comprising: a first die block (110); a second die block (120) on the first die block (110), the second die block (120) including a first chamber (122) configured for accommodating a mixture; a first slot (140) between the first die block (110) and the second die block (120); a third die block (130) on the second die block (120), the third die block (130) including a second chamber (132) configured for accommodating a barrier slurry; a second slot (150) between the third die block (130) and the second die block (120); a first spacer (142) in the first slot (140), and a second spacer (152) in the second slot (150), wherein the first spacer (142) includes: an inner region (I) connecting the first slot (140) to a first discharge port (144), the first discharge port (144) configured for setting a width of the mixture discharged from the first discharge port (144) and applied onto a substrate through the first discharge port (144), and a shielding protrusion (146) protruding from the inner region (I) toward the first discharge port (144); and wherein the second spacer (152) includes a pocket connecting the second slot (150) to a second discharge port (154), and wherein the second discharge port (154) overlaps with at least a part of an edge portion of the first discharge port (144).
2. The slot die coater (100) as claimed in claim 1, wherein the shielding protrusion (146) is in an inner center of the first spacer (142), the shielding protrusion (146) being separated from the first discharge port (144).
3. The slot die coater (100) as claimed in any of claims 1 or 2, wherein a central portion of the shielding protrusion (146) protrudes toward the first discharge port (144), wherein inclined sections symmetric to each other with respect to a center line of the shielding protrusion (146) are on opposite sides of the central portion.
4. The slot die coater (100) as claimed in any of claims 1 to 3, wherein: the first spacer (142) includes a base portion (410) and extension portions (420) that extend from one side of the base portion (410) toward the first discharge port (144), and the shielding protrusion (146) protrudes from the base portion (410) toward the first discharge port (144), the shielding protrusion (146) being between the extension portions (420).
5. The slot die coater (100) as claimed in claim 4, wherein terminals of two of the extension portions (420) at opposite ends of the first spacer (142), respectively, are bent towards a center of the first spacer (142).
6. The slot die coater (100) as claimed in claim 5, wherein at least a part of a terminal of one of the extension portions (420) positioned between the two of the extension portions (420), which are at opposite ends of the first spacer (142), is bent toward at least one of the two extension portions (420).
7. The slot die coater (100) as claimed in any of claims 4 to 6, wherein the shielding protrusion (146) is between two adjacent ones of the extension portions (420).
8. The slot die coater (100) as claimed in any of claims 1 to 7, wherein the second discharge port (154) overlaps with at least a part of each of opposite ends of the first discharge port (144).
9. The slot die coater (100) as claimed in any of claims 1 to 8, wherein the first slot (140) is with regard to a direction from the third die block (130) to the first die block (110) above the second slot (150).
10. The slot die coater (100) as claimed in claim 9, wherein: the first slot (140) extends horizontally between the first die block (110) and the second die block (120), and the second slot (150) extends between the second die block (120) and the third die block (130) at an oblique angle with respect to the first slot (140) so as to be closer to the first slot (140) at a position closer to the second discharge port (154).
11. The slot die coater (100) as claimed in any of claims 1 to 10, wherein a separation distance in a thickness direction between the first discharge port (144) and the second discharge port (154) is 0, the thickness direction relating to a direction from the third die block (130) to the first die block (110).
12. The slot die coater (100) as claimed in any of claims 1 to 11, wherein the second chamber (132) accommodates the barrier slurry and wherein the barrier slurry contains a water-soluble polymer.
13. The slot die coater (100) as claimed in claim 12, wherein the water-soluble polymer contains carboxymethyl cellulose salts.
14. The slot die coater (100) as claimed in any of claims 1 to 13, wherein the second spacer (152) includes pockets that are open toward the second discharge port (154), the pockets corresponding to the edge portion of the first discharge port (144).
15. The slot die coater (100) as claimed in claim 14, wherein the pockets extend in a direction oriented away from the second discharge port (154).

Description

BACKGROUND 1. Field Aspects of embodiments of the present disclosure relate to a slot die coater and an electrode for a secondary battery. 2. Description of the Related Art Unlike primary batteries that are not designed to be (re)charged, secondary (or rechargeable) batteries are batteries that are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable, small electronic devices, such as smart phones, feature phones, notebook computers, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for driving motors in hybrid vehicles and electric vehicles and for storing power (for example, home and/or utility scale power storage). A secondary battery generally includes an electrode assembly composed of a positive electrode and a negative electrode, a case accommodating the same, and electrode terminals connected to the electrode assembly. A slot die coating technique is one of key techniques used to uniformly apply active material slurry onto the electrode substrate in a secondary battery manufacturing process. A slot die coater is able to precisely control the viscosity and coating thickness of the slurry. Thus, the slot die coater can be used to stably produce high-quality electrodes. In a slot die coating process, a slurry applied through a slot of a slot die may be uniformly distributed over the substrate. As a result, such uniform coating directly affects performance and life of a battery. In a production of the electrodes for the secondary batteries, the slot die coating provides higher precision and consistency than roll coating, and has an advantage of minimizing waste in material. In other embodiments, the slot die coater is able to produce electrodes having various thicknesses by controlling a process speed thereof, and is thus suitable for mass production. A structure of the slot die coater has high mechanical stability and is capable of accurate coating on various substrates in accordance with the flow characteristics of the slurry. The above information disclosed in this background section is for enhancement of understanding of the background of the present disclosure, and therefore, it may contain information that does not constitute related (or prior) art. SUMMARY According to one or more embodiments of the present disclosure, a slot die coater includes a first die block, a second die block that is combined with the first die block to form a first slot and has a first chamber which accommodates a mixture, a third die block that is combined with the second die block to form a second slot and has a second chamber which accommodates a barrier slurry, a first spacer that is located in the first slot, and a second spacer that is located in the second slot, wherein the first spacer includes an inner region that is connected to a first discharge port configured to determine a width of an applied mixture layer in a case where the mixture is discharged and applied onto a substrate through the first discharge port connected to the first slot, and a shielding protrusion protruding in a direction toward the first discharge port from the inner region, and wherein the second spacer includes a pocket that is connected to a second discharge port which induces the barrier slurry to overlap with at least a part of an edge portion of the applied mixture layer in a case where the barrier slurry is discharged through the second discharge port connected to the second slot. In an embodiment, the shielding protrusion may be located in an inner center of the first spacer separated from the first discharge port. In an embodiment, a central portion of the shielding protrusion may protrude to be closest to the first discharge port, and inclined sections symmetric to each other with respect to a center line of the shielding protrusion may be located on both sides of the central portion. In an embodiment, the first spacer may include a base portion and a plurality of extension portions that extend from one side of the base portion in the direction of the first discharge port, and the shielding protrusion may protrude from the base portion in a direction toward the first discharge port and may be located between the plurality of extension portions. In an embodiment, terminals of two extension portions located at both ends of the first spacer among the plurality of extension portions may be bent toward a center of the first spacer. In an embodiment, at least a part of a terminal of an extension portion positioned between the two extension portions, which are located at both ends of the first spacer, may be bent toward at least one of the two extension portions. In an embodiment, the shielding protrusion may be located between two adjacent extension portions among the plurality of extension portions. In an embodiment, the second discharge port may overlap with at least a part of both ends of the first discharge port. In an embodiment, the f