Dual-slot die coater

Abstract

The disclosed dual-slot die coater includes a first die block having a first manifold for containing electrode slurry, an intermediate block coupled to the first die block, a first coater shim shaped to enclose both sides and rear of the first manifold and interposed between the first die block and the intermediate block, forming a first electrode slurry slot for discharging the electrode slurry filled in the first manifold, a second die block having a second manifold for containing electrode slurry and coupled to the intermediate block, and a second coater shim shaped to enclose both sides and rear of the second manifold and interposed between the second die block and the intermediate block, forming a second electrode slurry slot for discharging the electrode slurry filled in the second manifold, wherein insulating fluid supply channels for supplying insulating fluid to the insulating fluid channels of the first and second coater shims are formed penetrating the intermediate block.

Description

Technical Field

[0001] The present invention relates to a dual slot die coater, and more particularly to a dual slot die coater in which an insulating liquid flow path structure for supplying an insulating liquid discharged simultaneously with an electrode slurry to a lower layer and / or an upper layer is efficiently implemented.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0055122 filed on April 25, 2024, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference.

Background Art

[0003] In recent years, lithium secondary batteries have been widely applied not only to small devices such as portable electronic devices but also to medium and large devices such as battery packs or power storage devices for hybrid vehicles and electric vehicles. In particular, in recent years, as interest in environmental issues has increased, many studies have been conducted on electric vehicles and hybrid vehicles that can replace gasoline vehicles and diesel vehicles using fossil fuels, which are one of the main causes of air pollution.

[0004] Generally, a lithium secondary battery has a structure in which an electrode assembly including a positive electrode, a negative electrode, and a separator is impregnated with a lithium electrolyte. The electrode is formed by coating an electrode current collector with an electrode slurry containing an electrode active material. For coating the electrode slurry, a coating device such as a slot die coater is used.

[0005] The slot die coater includes an upper die block and a lower die block that form a chamber for supplying an electrode slurry, and a shim member disposed therebetween for setting the height and width of a slot for discharging the active material slurry. A space between a plurality of shim members forms the slot. The height of the slot for discharging the active material slurry is determined by the height of the shim member, and the width of the slot is determined as the distance between spaced-apart shim members.

[0006] When coating electrode slurry using a slot die coater, the shape of the edge changes depending on the degree to which the electrode slurry spreads (sliding length). If the degree of electrode slurry spread is small, the sliding length that reduces the edge thickness becomes shorter, forming a region that is thicker than the average thickness. This increases the risk of wire breakage due to the side ring during winding of the electrode roll, and the risk of the N / P ratio reversal.

[0007] Conversely, if the electrode slurry spreads too much, the sliding length increases and the edge thickness decreases. This reduces the capacity by the length of the sliding section and creates a risk of lithium deposition due to air trapping. Thus, various aspects such as electrode capacity, safety, and lifespan are greatly affected by the sliding length of the electrode slurry. To control this, a technique of simultaneously discharging insulating liquid to the edge side of the electrode slurry can be applied. The insulating liquid acts as a kind of dam to control the amount the electrode slurry spreads, and by adjusting the discharge amount and width of the insulating liquid, the electrode slurry can be controlled to spread to an appropriate level.

[0008] Electrode slurry and insulating liquid are discharged simultaneously onto the moving electrode, and for this purpose, the shim members of the slot die coater are provided with insulating liquid channels. For example, the shim members consist of two types: body shims and spacer shims, and multiple spacer shims may be arranged in the empty area inside the body shim. The space between the spacer shims forms the discharge slot for the electrode slurry, while the insulating liquid is discharged through the insulating liquid channels formed in a concave shape on the surface of the spacer shims.

[0009] Slot die coaters have recently evolved into dual-layer slot die coaters (DLDs). Dual-layer slot die coaters are slot die coaters that simultaneously discharge electrode slurries in two layers. By using different series and compositions for the lower electrode slurry that directly contacts the electrodes and the upper electrode slurry that is layered on top of the lower electrode slurry, the performance of secondary batteries can be greatly improved. For example, by applying different electrode slurries—one with a composition that provides excellent adhesion to the electrodes and another with a composition that provides excellent electrolyte impregnation—charging capacity and charging speed can be improved.

[0010] In dual-slot die coaters, a technique of simultaneously discharging the electrode slurry and insulating liquid can be applied to control the sliding phenomenon of the electrode slurry. However, because dual-slot die coaters have a multilayer structure, there is a problem in that the structure for supplying insulating liquid alongside the lower and / or upper electrode slurry slots becomes complex. [Overview of the project] [Problems that the invention aims to solve]

[0011] The present invention aims to provide a dual-slot die coater that can efficiently implement an insulating liquid channel structure that supplies insulating liquid, which is discharged simultaneously with the electrode slurry, to the lower and / or upper layers.

[0012] However, the technical problems that this invention aims to solve are not limited to those described above, and other problems not mentioned can be clearly understood by an ordinary person from the description of the invention below. [Means for solving the problem]

[0013] The present invention relates to a dual-slot die coater, and in one embodiment comprises a first die block having a first manifold for containing electrode slurry, an intermediate block coupled to the first die block, and a first coater shim that wraps around both sides and the rear of the first manifold. The present invention comprises: a first coat shim having an around shape, interposed between a first die block and an intermediate block, and forming a first electrode slurry slot for discharging electrode slurry filled in a first manifold; a second die block having a second manifold for containing electrode slurry and coupled to an intermediate block; and a second coat shim having a shape that encloses both sides and the rear of the second manifold, interposed between the second die block and the intermediate block, and forming a second electrode slurry slot for discharging electrode slurry filled in the second manifold, wherein the first and second coat shims each have a first insulating liquid channel and a second insulating liquid channel, respectively, forming a first insulating liquid slot and a second insulating liquid slot for discharging insulating liquid, and an insulating liquid supply channel for supplying insulating liquid to the first insulating liquid channel and the second insulating liquid channel is formed penetrating the intermediate block.

[0014] The insulating fluid supply channel may include a main channel that runs laterally along the longitudinal direction of the intermediate block, and branch channels that branch off from the main channel and run vertically through the intermediate block.

[0015] Furthermore, both ends of the branched channel can be connected to the closed ends of the first insulating fluid channel and the second insulating fluid channel, respectively.

[0016] In one embodiment, the first insulating fluid channel may be formed in a concave shape on one side surface of the first coating shim that is in close contact with the intermediate block.

[0017] Furthermore, the second insulating fluid channel can be formed in a concave shape on one side surface of the second coating shim that is in close contact with the intermediate block.

[0018] In one embodiment of the present invention, the first coat shim may include a first body shim shaped to enclose both sides and the rear of the first manifold, and a plurality of first spacer shims spaced apart between the first body shims so as to traverse toward the front of the first manifold, with first insulating fluid channels formed on their surfaces.

[0019] The second coater shim may include a second body shim shaped to enclose both sides and the rear of the second manifold, and a plurality of second spacer shims spaced apart between the second body shims so as to traverse toward the front of the second manifold, with second insulating fluid channels formed on their surfaces.

[0020] In one embodiment, one end of the main flow path is an insulating liquid inlet, and the other end may be closed.

[0021] Alternatively, in another embodiment, both ends of the main flow path may be insulating liquid inlets.

[0022] On the other hand, in the dual-slot die coater of the present invention, the electrode slurries filled into the first manifold and the second manifold, respectively, may be different electrode slurries that are distinct from each other. [Effects of the Invention]

[0023] In the dual-slot die coater of the present invention having the above configuration, manifolds for containing electrode slurry are arranged in the first die block and the second die block, respectively, while the insulating liquid supply channel is formed by penetrating the intermediate block. As a result, the insulating liquid supply channel is directly connected to the insulating liquid channels of the first coater shim and the second coater shim, which are in close contact with the upper and lower surfaces of the intermediate block, without passing through the first die block and the second die block.

[0024] Thus, by structuring the insulation liquid supply flow path to be separated from the manifolds on the first die block and the second die block and formed in the intermediate block, the complex flow path structure of the dual slot die coater that discharges the electrode slurry and the insulation liquid simultaneously can be simplified. Such a simplified flow path structure not only reduces the manufacturing cost of the dual slot die coater, but also has advantages in long-term maintenance.

[0025] However, the technical effects obtainable by the present invention are not limited to the above-described effects, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0026] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited only to the matters described in such drawings.

Brief Description of the Drawings

[0027] [Figure 1] It is a perspective view showing a dual slot die coater according to an embodiment of the present invention. [Figure 2] It is an exploded perspective view of the dual slot die coater of FIG. 1. [Figure 3] It is a front view of the dual slot die coater of FIG. 1. [Figure 4] It is a cross-sectional view taken along the line “A - A” of FIG. 1. [Figure 5] It is a cross-sectional view taken along the line “B - B” of FIG. 1. [Figure 6] It is a view showing an embodiment in which one end of the main flow path is an insulation liquid inlet and the other end is blocked. [Figure 7] It is a view showing an embodiment in which both open ends of the main flow path are set as insulation liquid inlets.

Modes for Carrying Out the Invention

[0028] Because the present invention can be modified in various ways and may have a variety of embodiments, specific embodiments are described in detail below.

[0029] However, this is not intended to limit the present invention to any particular embodiment, but rather should be understood to include all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0030] In the present invention, terms such as "includes" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof as described in the specification, without prejudice to the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0031] Furthermore, in this invention, when a part such as a layer, film, region, or plate is described as being "on top" of another part, this includes not only the case where it is "directly above" the other part, but also the case where another part is located in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "directly below" the other part, but also the case where another part is located in between. Also, in this application, being "on top" may include being located not only at the top but also at the bottom.

[0032] The present invention relates to a dual-slot die coater, and in one embodiment, a first die block having a first manifold for containing electrode slurry, an intermediate block coupled to the first die block, a first coater shim having a shape that encloses both sides and the rear of the first manifold, interposed between the first die block and the intermediate block, and forming a first electrode slurry slot for discharging the electrode slurry filled in the first manifold, a second die block having a second manifold for containing electrode slurry and coupled to the intermediate block, and a second coater shim The first coat shim and the second coat shim are provided with a first insulating liquid channel and a second insulating liquid channel, respectively, which form a first insulating liquid channel and a second insulating liquid channel, which form a first insulating liquid channel and a second insulating liquid channel, which form a first insulating liquid channel and a second insulating liquid channel, which discharge insulating liquid to the first insulating liquid channel and the second insulating liquid channel, respectively, and an insulating liquid supply channel for supplying insulating liquid to the first insulating liquid channel and the second insulating liquid channel is formed by penetrating the intermediate block.

[0033] In the dual-slot die coater of the present invention having the above configuration, manifolds for containing electrode slurry are arranged in the first die block and the second die block, respectively, while the insulating liquid supply channel is formed by penetrating the intermediate block. As a result, the insulating liquid supply channel is directly connected to the insulating liquid channels of the first coater shim and the second coater shim, which are in close contact with the upper and lower surfaces of the intermediate block, without passing through the first die block and the second die block.

[0034] Thus, by structurally separating the insulating fluid supply channel from the manifolds on the first and second die blocks and forming it in the intermediate block, the complex flow path structure of a dual-slot die coater that simultaneously discharges electrode slurry and insulating fluid can be simplified. This simplified flow path structure not only reduces the manufacturing cost of the dual-slot die coater but also has positive effects on long-term maintenance.

[0035] Specific embodiments of the dual-slot die coater 10 according to the present invention will be described in detail below with reference to the attached drawings. For reference, the front-to-back and up-down-left-right directions used in the following description to specify relative positions are for the purpose of aiding the understanding of the invention, and unless otherwise specified, the directions shown in the drawings shall be used as the reference.

[0036] (First Embodiment) Figure 1 is a perspective view showing a dual-slot die coater 10 according to one embodiment of the present invention, and Figure 2 is an exploded perspective view of the dual-slot die coater 10 of Figure 1.

[0037] The present invention relates to a dual-slot die coater 10, which, as shown in Figures 1 and 2, includes a first die block 100, an intermediate block 200, and a second die block 300, and further includes a first coater shim 400 interposed between the first die block 100 and the intermediate block 200, and a second coater shim 500 interposed between the second die block 300 and the intermediate block 200.

[0038] The first die block 100 includes a first manifold 110 for containing electrode slurry, and the second die block 300 includes a second manifold 310 for containing electrode slurry. An intermediate block 200 is interposed between the first die block 100 and the second block. Based on the drawing, it can be understood that the structure consists of the first die block 100, the intermediate block 200, and the second die block 300 stacked sequentially from bottom to top and interconnected. A single row of electrode slurry slots is formed above and below the intermediate block 200. As a result, electrode slurry is discharged in two layers to the moving electrode.

[0039] Depending on the embodiment, the electrode slurries filled into the first manifold 110 and the second manifold 310, respectively, may be different electrode slurries distinct from each other. This allows for a significant improvement in the performance of the secondary battery by using different series and compositions for the lower electrode slurry that directly contacts the electrodes and the upper electrode slurry that is layered on top of the lower electrode slurry. For example, by applying different electrode slurries, such as a lower electrode slurry with a composition that provides excellent adhesion to the electrodes and an upper electrode slurry with a composition that provides excellent electrolyte impregnation, the charging capacity and charging speed of the secondary battery can be improved.

[0040] The first coat shim 400 is interposed between the first die block 100 and the intermediate block 200, forming a first electrode slurry slot 440 from which the electrode slurry filled in the first manifold 110 of the first die block 100 is discharged. The first coat shim 400 has a shape that encloses both sides and the rear of the first manifold 110, forming a thin, elongated open surface on the front surface 12 of the dual-slot die coater 10. This open surface forms the first electrode slurry slot 440. The height of the first electrode slurry slot 440 is determined by the thickness of the first coat shim 400 (thickness after assembly). The width of the first electrode slurry slot 440 is determined by the width of the open surface formed by the first coat shim 400.

[0041] Similarly, the second coat shim 500 is interposed between the second die block 300 and the intermediate block 200. The second coat shim 500 is shaped to enclose both sides and the rear of the second manifold 310 of the second die block 300, thereby forming a second electrode slurry slot 540 from which the electrode slurry filled in the second manifold 310 is discharged.

[0042] The first coater shim 400 and the second coater shim 500 are provided with a first insulating liquid channel 430 and a second insulating liquid channel 530, respectively, which form a first insulating liquid slot 450 and a second insulating liquid slot 550 for discharging insulating liquid. Figure 3 is a front view of the dual-slot die coater 10 of Figure 1, where the first insulating liquid slot 450 formed by the open end of the first insulating liquid channel 430 is arranged adjacent to both sides of the first electrode slurry slot 440. As a result, when the electrode slurry of the first manifold 110 is discharged, insulating liquid is discharged to both side edge regions at the same time. In the dual-slot die coater 10 of one embodiment shown in Figures 1 and 2, there are two first electrode slurry slots 440, so that the electrode slurry of the first manifold 110 is discharged in two rows. Correspondingly, there are four first insulating liquid slots 450. Similarly, the second insulating liquid slot 550 formed by the open end of the second insulating liquid channel 530 is located adjacent to both sides of the second electrode slurry slot 540.

[0043] Figure 4 is a cross-sectional view along the line "AA" in Figure 1. Referring to Figure 4, the electrode slurry filled in the first manifold 110 of the first die block 100 is discharged through the thin, elongated first electrode slurry slot 440 to the front surface 12 of the first die block 100 and the intermediate block 200. Similarly, the electrode slurry filled in the second manifold 310 of the second die block 300 is discharged through the thin, elongated second electrode slurry slot 540 to the front surface 12 of the second die block 300 and the intermediate block 200.

[0044] As shown in Figure 4, the intermediate block 200 does not have a hollow section for containing electrode slurry. Instead, as clearly shown in the "BB" cross section of Figure 5, insulating fluid supply channels 210 are formed through the intermediate block 200 to supply insulating fluid to the first insulating fluid channel 430 and the second insulating fluid channel 530, respectively. In one example, the insulating fluid supply channels 210 may include a main channel 212 that runs laterally along the longitudinal direction of the intermediate block 200 and a branch channel 214 that branches off from the main channel 212 and runs vertically through the intermediate block 200. The ends of the branch channel 214 can be connected to the closed ends (inner ends) of the first insulating fluid channel 430 and the second insulating fluid channel 530, respectively.

[0045] Thus, in the dual-slot die coater 10 of the present invention, the insulating liquid supply channel 210 is structurally separated from the first manifold 110 and the second manifold 310 on the first die block 100 and the second die block 300 and formed in the intermediate block 200, thereby simplifying the complex channel structure of the dual-slot die coater 10 that simultaneously discharges electrode slurry and insulating liquid. This simplified channel structure not only reduces the manufacturing cost of the dual-slot die coater 10 but is also advantageous for long-term maintenance.

[0046] As shown in Figures 3 and 5, the first insulating fluid channel 430 is formed concavely on one side surface of the first coater shim 400 that is in close contact with the intermediate block 200, and the second insulating fluid channel 530 is formed concavely on one side surface of the second coater shim 500 that is in close contact with the intermediate block 200. The insulating fluid penetrates the intermediate block 200 and is supplied to the closed ends of the first insulating fluid channel 430 and the second insulating fluid channel 530. The grooves of the first insulating fluid channel 430 and the second insulating fluid channel 530 are discharged to the side that is in close contact with the intermediate block 200. Structurally, the possibility of insulating fluid mixing with the electrode slurry inside the dual-slot die coater 10 is extremely low.

[0047] On the other hand, in the dual-slot die coater 10 of the present invention, the coater shims 400 and 500 may be one-piece structures, but as shown in the drawings, they may consist of a two-piece structure of body shims 410 and 510 and spacer shims 420 and 520. That is, the first coater shim 400 may include a first body shim 410 shaped to enclose both sides and the rear surface of the first manifold 110, and a plurality of first spacer shims 420 spaced apart between the first body shims 410 so as to cross toward the front surface 12 of the first manifold 110. Here, a first insulating liquid channel 430 is formed on the surface of the plurality of first spacer shims 420. Similarly, the second coater shim 500 may include a second body shim 510 and a plurality of second spacer shims 520.

[0048] In each coater shim 400, 500, the thickness of the body shim 410, 510 and the spacer shim 420, 520 are substantially the same, and this thickness determines the height of the electrode slurry slot 440, 540 from which the electrode slurry is discharged. By constructing each coater shim 400, 500 as a two-piece structure consisting of a body shim 410, 510 and a spacer shim 420, 520, only the spacer shim 420, 520 can be replaced instead of the entire coater shim 400, 500, which is efficient in terms of maintenance effort and cost.

[0049] (Second Embodiment) In the second embodiment, an embodiment is described in which insulating liquid is supplied to the first insulating liquid channel 430 and the second insulating liquid channel 530 via an insulating liquid supply channel 210 formed through the intermediate block 200.

[0050] Figure 6 shows a structure in which one end of the open main channel 212, which penetrates laterally along the longitudinal direction of the intermediate block 200, is composed of an insulating liquid inlet 220, and the other end is closed. Because one end of the main channel 212 is closed, the main channel 212 is pressurized and filled with insulating liquid supplied to the insulating liquid inlet 220, and a portion of the filled insulating liquid is supplied to the first insulating liquid channel 430 and the second insulating liquid channel 530 through the branch channel 214 and discharged from the first insulating liquid slot 450 and the second insulating liquid slot 550.

[0051] Figure 7 shows a structure in which both open ends of the main flow path 212, which penetrates laterally along the longitudinal direction of the intermediate block 200, are configured with insulating liquid inlets 220. In the embodiment of Figure 6, when the lateral length of the dual-slot die coater 10 is long, the flow rate of insulating liquid supplied to the first insulating liquid flow path 430 and the second insulating liquid flow path 530 decreases as the distance from the insulating liquid inlet 220 increases, which can lead to a large difference in the amount of insulating liquid discharged in the multiple first insulating liquid slots 450 and second insulating liquid slots 550.

[0052] Figure 7 shows a configuration for reducing such deviations in the amount of insulating fluid discharged, in which insulating fluid is supplied to both sides of the main flow path 212. By supplying insulating fluid to both sides of the lateral length of the dual-slot die coater 10, the deviation in the amount of insulating fluid discharged in the entire first insulating fluid slot 450 and second insulating fluid slot 550 can be reduced.

[0053] The present invention has been described in more detail above with reference to the drawings and embodiments. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, at the time of filing, there may be various equivalents and modifications that can substitute for them. [Explanation of Symbols]

[0054] 10: Dual-slot die coater 12:Front 100: First Die Block 110: First Manifold 200: Intermediate Block 210: Insulating fluid supply channel 212: Main channel 214: Branch channel 220: Insulating liquid inlet 300: Second Die Block 310: Second Manifold 400: First Courtesy 410: First Body Sim 420: First spacer shim 430: First insulating fluid channel 440: First electrode slurry slot 450: First insulating liquid slot 500: Second Courtesy 510: Second Body Sim 520: Second spacer shim 530: Second insulating fluid channel 540: Second electrode slurry slot 550: Second insulating liquid slot

Claims

1. A first die block comprising a first manifold for containing electrode slurry, The intermediate block connected to the first die block, A first coating shim having a shape that encloses both sides and the rear of the first manifold, interposed between the first die block and the intermediate block, and forming a first electrode slurry slot for discharging the electrode slurry filled in the first manifold, A second die block, which includes a second manifold for containing electrode slurry and is coupled to the intermediate block, A second coating shim, having a shape that encloses both sides and the rear of the second manifold, interposed between the second die block and the intermediate block, and forming a second electrode slurry slot for discharging the electrode slurry filled in the second manifold, is included. The first coat shim and the second coat shim are each provided with a first insulating liquid channel and a second insulating liquid channel, which form a first insulating liquid slot and a second insulating liquid slot for discharging insulating liquid, respectively. A dual-slot die coater in which an insulating liquid supply channel for supplying insulating liquid to the first insulating liquid channel and the second insulating liquid channel is formed by penetrating the intermediate block.

2. The insulating fluid supply channel is The main channel extends laterally along the longitudinal direction of the aforementioned intermediate block, The dual-slot die coater according to claim 1, further comprising a branch channel that branches off from the main channel and penetrates the intermediate block in the vertical direction.

3. The dual slot die coater according to claim 2, wherein both ends of the branched flow path are connected to the closed ends of the first insulating fluid flow path and the second insulating fluid flow path, respectively.

4. The dual-slot die coater according to claim 3, wherein the first insulating fluid channel is formed in a concave shape on one side surface of the first coater shim which is in close contact with the intermediate block.

5. The dual-slot die coater according to claim 4, wherein the second insulating fluid channel is formed in a concave shape on one side surface of the second coater shim which is in close contact with the intermediate block.

6. The first coatasim is, A first body shim having a shape that encloses both sides and the rear of the first manifold, A dual-slot die coater according to any one of claims 1 to 5, comprising: a plurality of first spacer shims, spaced apart between the first body shims so as to span across the front surface of the first manifold, and having the first insulating fluid flow path formed on its surface.

7. The aforementioned second coating is, A second body shim having a shape that encloses both sides and the rear of the second manifold, The dual-slot die coater according to claim 6, comprising a plurality of second spacer shims, spaced apart between the second body shims so as to span across the front of the second manifold, and having the second insulating fluid flow path formed on its surface.

8. The dual-slot die coater according to any one of claims 2 to 5, wherein one end of the main flow path is an insulating liquid inlet and the other end is closed.

9. The dual-slot die coater according to any one of claims 2 to 5, wherein both ends of the main flow path are insulating liquid inlets.

10. The dual-slot die coater according to any one of claims 1 to 5, wherein the electrode slurries filled in the first manifold and the second manifold, respectively, are different electrode slurries that are distinct from each other.

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