Dual-slot die coater

Abstract

The disclosed dual-slot die coater comprises: a first die block that has a first manifold for accommodating electrode slurry; an intermediate block coupled to the first die block; a first coater shim which is shaped to encompass two side surfaces and the rear surface of the first manifold, and which is interposed between the first die block and the intermediate block so as to form a first electrode slurry slot through which the electrode slurry filled in the first manifold is discharged; a second die block that has a second manifold for accommodating electrode slurry, and is coupled to the intermediate block; and a second coater shim which is shaped to encompass two side surfaces and the rear surface of the second manifold, and which is interposed between the second die block and the intermediate block so as to form a second electrode slurry slot through which the electrode slurry filled in the second manifold is discharged, wherein an insulating liquid supply flow path for supplying an insulating liquid to an insulating liquid flow path of each of the first coater shim and the second coater shim passes through the intermediate block.

Description

Dual slot die coater

[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 path structure is efficiently implemented for supplying an insulating liquid discharged simultaneously with an electrode slurry to a lower layer and / or an upper layer.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0055122, filed April 25, 2024, the entire contents of which are incorporated herein by reference.

[0003] Lithium secondary batteries are now widely used not only in small devices like portable electronic devices, but also in medium- to large-sized devices like battery packs for hybrid and electric vehicles and power storage systems. In particular, with growing concern over environmental issues, research is being conducted on electric and hybrid vehicles, which can replace fossil fuel-powered vehicles like gasoline and diesel, a major source of air pollution.

[0004] Typically, lithium secondary batteries have an electrode assembly structure consisting of a positive electrode, negative electrode, and separator, impregnated with a lithium electrolyte. The electrode is formed by coating an electrode current collector with an electrode slurry containing an electrode active material. A coating device such as a slot die coater is used to coat the electrode slurry.

[0005] A slot die coater includes an upper die block and a lower die block forming a chamber for supplying electrode slurry, and a core member disposed between the upper and lower die blocks to set the height and width of a slot for discharging active material slurry. The space between the plurality of core members forms a slot. The height of the slot for discharging the active material slurry is determined by the height of the core member, and the width of the slot is determined by the distance between the spaced-apart core members.

[0006] When electrode slurry coating is performed using a slot die coater, the shape of the edge varies depending on the extent to which the electrode slurry spreads (sliding length). If the extent of electrode slurry spreading is small, the sliding length that reduces the thickness of the edge is shortened, forming an area thicker than the average thickness. This increases the risk of short circuits occurring due to the side ring during electrode roll winding and a reversal of the N / P ratio.

[0007] Conversely, if the spreading degree of the electrode slurry is large, the sliding length becomes longer and the thickness of the edge decreases, which leads to a decrease in the capacity as much as the sliding part becomes worn, and there is a risk of lithium precipitation due to air traps. Since various aspects of the electrode, such as the capacity, safety, and lifespan, are greatly affected by the sliding length of the electrode slurry, a technology that simultaneously discharges the insulating liquid on the edge of the electrode slurry can be applied to control this. The insulating liquid acts as a kind of dam that controls the amount of the electrode slurry spreading, and by adjusting the amount and width of the insulating liquid discharge, the electrode slurry can be controlled to spread to an appropriate level.

[0008] Electrode slurry and insulating liquid are simultaneously discharged onto the running electrode, and for this purpose, an insulating liquid path is provided in the core member of the slot die coater. For example, the core member is composed of two types: a body core and a spacer core, and a plurality of spacer cores can be arranged in a blank area inside the body core. The space between the spacer cores forms a discharge slot for the electrode slurry, and the insulating liquid is discharged through an insulating liquid path concavely formed on the surface of the spacer core.

[0009] Slot die coaters have recently been developed into dual-layer slot die coaters (Dual Layer Slot Die Coaters, DLD). A dual-slot die coater is a slot die coater that simultaneously discharges electrode slurry in two layers. By differentiating the series and composition of the lower electrode slurry that directly contacts the electrode and the upper electrode slurry that is laminated over the lower electrode slurry, the performance of secondary batteries can be significantly improved. For example, the lower electrode slurry can be made of a composition that has excellent adhesion to the electrode, while the upper electrode slurry can be made of a composition that has excellent electrolyte impregnation properties. By applying different electrode slurries, the charging capacity, charging speed, etc. can be improved.

[0010] Even in a dual-slot die coater, a technique for simultaneously discharging electrode slurry and insulating liquid can be applied to control the sliding phenomenon of the electrode slurry. However, due to the multi-layer structure of the dual-slot die coater, there is a problem in that the structure for supplying the insulating liquid next to the lower and / or upper electrode slurry slots becomes complicated.

[0011] The purpose of the present invention is to provide a dual slot die coater capable of efficiently implementing an insulating liquid path structure that supplies an insulating liquid discharged simultaneously with an electrode slurry to a lower layer and / or an upper layer.

[0012] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0013] The present invention relates to a dual slot die coater, and in one embodiment, the dual slot die coater comprises: a first die block having a first manifold for receiving electrode slurry; an intermediate block coupled to the first die block; a first coater shim formed in a form that surrounds both sides and the rear surface of the first manifold, and interposed between the first die block and the intermediate block to form a first electrode slurry slot for discharging electrode slurry filled in the first manifold; a second die block having a second manifold for receiving electrode slurry, coupled to the intermediate block; and a second coater shim formed in a form that surrounds both sides and the rear surface of the second manifold, and interposed between the second die block and the intermediate block to form a second electrode slurry slot for discharging electrode slurry filled in the second manifold; and the first coater shim and the second coater shim each form a first insulating liquid channel and a second insulating liquid channel for discharging an insulating liquid. And, an insulating liquid supply path for supplying insulating liquid to the first insulating liquid path and the second insulating liquid path is formed by penetrating the intermediate block.

[0014] The above insulating liquid supply path may include a main path that extends horizontally along the length of the intermediate block, and a branch path that branches off from the main path and extends vertically through the intermediate block.

[0015] And, both ends of the branch flow path can be connected to the closed ends of the first insulating flow path and the second insulating flow path, respectively.

[0016] In one embodiment, the first insulating fluid path may be formed concavely on one surface of the first coater core that is in close contact with the intermediate block.

[0017] And, the second insulating fluid path can be formed concavely on one surface of the second coater core that is in close contact with the intermediate block.

[0018] And, in one embodiment of the present invention, the first coater core may include a first body core having a shape that surrounds both sides and the rear surface of the first manifold, and a plurality of first spacer cores spaced apart from each other so as to extend across the front surface of the first manifold and having the first insulating liquid path formed on the surface thereof.

[0019] In addition, the second coater core may include a second body core that surrounds both sides and the rear surface of the second manifold, and a plurality of second spacer cores that are spaced apart from each other so as to extend across the front surface of the second manifold and have the second insulating liquid path formed on the surface thereof.

[0020] In one embodiment, the main euro may have one end as an insulating liquid inlet and the other end as a closed end.

[0021] Alternatively, in another embodiment, the main euro may have both ends as inlets for insulating liquid.

[0022] Meanwhile, in the dual slot die coater of the present invention, the electrode slurries filled in the first manifold and the second manifold may be different electrode slurries that are distinct from each other.

[0023] The dual slot die coater of the present invention having the above configuration has manifolds for accommodating electrode slurry arranged in the first die block and the second die block, respectively, while the insulating liquid supply path is formed by penetrating the middle block, so that the insulating liquid supply path is directly connected to the insulating liquid paths of the first and second coater cores that are in close contact with the upper and lower surfaces of the middle block without passing through the first and second die blocks.

[0024] In this way, the insulating liquid supply path is structurally separated from the manifolds on the first and second die blocks and formed in the middle block, thereby simplifying the complex flow path structure of the dual slot die coater that simultaneously discharges electrode slurry and insulating liquid. This simplified flow path structure not only reduces the manufacturing cost of the dual slot die coater, but also has advantages in long-term maintenance and service.

[0025] However, the technical effects that can be obtained through the present invention are not limited to the above-described effects, and other effects that are 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 together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0027] FIG. 1 is a perspective view illustrating a dual slot die coater according to one embodiment of the present invention.

[0028] Figure 2 is an exploded perspective view of the dual slot die coater of Figure 1.

[0029] Figure 3 is a front view of the dual slot die coater of Figure 1.

[0030] Figure 4 is a cross-sectional view along line “AA” of Figure 1.

[0031] Figure 5 is a cross-sectional view along the line “BB” of Figure 1.

[0032] Figures 6 and 7 are drawings showing two embodiments in which the open ends of the main euro are set as insulating liquid inlets.

[0033] [Explanation of symbols]

[0034] 10: Dual slot die coater 12: Front

[0035] 100: 1st die block 110: 1st manifold

[0036] 200: Middle block 210: Insulating fluid supply path

[0037] 212: Main Euro 214: Quarter Euro

[0038] 220: Insulating fluid inlet 300: Second die block

[0039] 310: Second manifold 400: First coater core

[0040] 410: First body seam 420: First spacer seam

[0041] 430: First insulating liquid Euro 440: First electrode slurry slot

[0042] 450: 1st insulating liquid slot 500: 2nd coater core

[0043] 510: Second body core 520: Second spacer core

[0044] 530: Second insulating liquid Euro 540: Second electrode slurry slot

[0045] 550: Second insulation slot

[0046]

[0047] The present invention can be modified in various ways and has many embodiments, and specific embodiments will be described in detail below.

[0048] However, this is not intended to limit the present invention to a specific embodiment, but should be understood to include all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention.

[0049] In the present invention, it should be understood that terms such as “include” or “have” are intended to specify the presence of a feature, number, step, operation, component, part or combination thereof described in the specification, but do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.

[0050] Additionally, in the present invention, when a part such as a layer, film, region, or plate is described as being "on" another part, this includes not only cases where it is "directly above" the other part, but also cases where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is described as being "under" another part, this includes not only cases where it is "directly below" the other part, but also cases where there is another part in between. Furthermore, in the present application, "being placed on" may include cases where it is placed below as well as above.

[0051]

[0052] The present invention relates to a dual slot die coater, and in one embodiment, the dual slot die coater comprises: a first die block having a first manifold for receiving electrode slurry; an intermediate block coupled to the first die block; a first coater shim formed in a form that surrounds both sides and the rear surface of the first manifold, and interposed between the first die block and the intermediate block to form a first electrode slurry slot for discharging electrode slurry filled in the first manifold; a second die block having a second manifold for receiving electrode slurry, coupled to the intermediate block; and a second coater shim formed in a form that surrounds both sides and the rear surface of the second manifold, and interposed between the second die block and the intermediate block to form a second electrode slurry slot for discharging electrode slurry filled in the second manifold; and the first coater shim and the second coater shim each form a first insulating liquid channel and a second insulating liquid channel for discharging an insulating liquid. And, an insulating liquid supply path for supplying insulating liquid to the first insulating liquid path and the second insulating liquid path is formed by penetrating the intermediate block.

[0053] The dual slot die coater of the present invention having the above configuration has manifolds for accommodating electrode slurry arranged in the first die block and the second die block, respectively, while the insulating liquid supply path is formed by penetrating the middle block, so that the insulating liquid supply path is directly connected to the insulating liquid paths of the first and second coater cores that are in close contact with the upper and lower surfaces of the middle block without passing through the first and second die blocks.

[0054] In this way, the insulating liquid supply path is structurally separated from the manifolds on the first and second die blocks and formed in the middle block, thereby simplifying the complex flow path structure of a dual-slot die coater that simultaneously dispenses electrode slurry and insulating liquid. This simplified flow path structure not only reduces the manufacturing cost of the dual-slot die coater but also has a positive effect on long-term maintenance.

[0055] Hereinafter, a specific embodiment of a dual slot die coater (10) according to the present invention will be described in detail with reference to the attached drawings. For reference, the directions of front / back, up / down / left / right, etc., used to designate relative positions in the following description are intended to aid understanding of the invention, and unless otherwise specifically defined, the directions shown in the drawings are taken as a reference.

[0056]

[0057] [First Embodiment]

[0058] FIG. 1 is a perspective view illustrating a dual slot die coater (10) according to one embodiment of the present invention, and FIG. 2 is an exploded perspective view of the dual slot die coater (10) of FIG. 1.

[0059] The present invention relates to a dual slot die coater (10), which includes a first die block (100), a middle block (200), and a second die block (300), as shown in FIGS. 1 and 2, and further includes a first coater shim (400) interposed between the first die block (100) and the middle block (200), and a second coater shim (500) interposed between the second die block (300) and the middle block (200).

[0060] The first die block (100) has a first manifold (110) for receiving electrode slurry, and the second die block (300) has a second manifold (310) for receiving electrode slurry. An intermediate block (200) is interposed between the first die block (100) and the second block. Referring to the drawing, the first die block (100), the intermediate block (200), and the second die block (300) can be understood as a structure in which the first die block (100), the intermediate block (200), and the second die block (300) are sequentially stacked and mutually coupled from below. Based on the intermediate block (200), a row of electrode slurry slots is formed vertically. Accordingly, the electrode slurry is discharged in two layers to the moving electrode.

[0061] Depending on the embodiment, the electrode slurry filled in the first manifold (110) and the second manifold (310) may be different electrode slurries that are distinct from each other. Accordingly, by differentiating the series, composition, etc. of the lower electrode slurry that directly contacts the electrode and the upper electrode slurry that is laminated on the lower electrode slurry, the performance of the secondary battery can be significantly improved. For example, by applying different electrode slurries, such as the lower electrode slurry having a composition that has excellent adhesion to the electrode and the upper electrode slurry having a composition that has excellent impregnation properties of the electrolyte, the charging capacity, charging speed, etc. of the secondary battery can be improved.

[0062] The first coater shim (400) is interposed between the first die block (100) and the intermediate block (200) to form a first electrode slurry slot (440) for discharging electrode slurry filled in the first manifold (110) of the first die block (100). The first coater shim (400) has a shape that surrounds both sides and the rear surface of the first manifold (110), and forms a thin and long open surface toward 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 defined by the thickness (thickness after assembly) of the first coater shim (400). In addition, the width of the first electrode slurry slot (440) is defined by the width of the open surface formed by the first coater shim (400).

[0063] Similarly, the second coater shim (500) is interposed between the second die block (300) and the intermediate block (200). In addition, the second coater shim (500) is formed to surround both sides and the rear surface of the second manifold (310) of the second die block (300), thereby forming a second electrode slurry slot (540) for discharging the electrode slurry filled in the second manifold (310).

[0064] In addition, the first coater core (400) and the second coater core (500) are provided with a first insulating liquid path (430) and a second insulating liquid path (530) which form a first insulating liquid slot (450) and a second insulating liquid slot (550) for discharging the insulating liquid, respectively. Fig. 3 is a front view of the dual slot die coater (10) of Fig. 1, wherein the first insulating liquid slot (450) formed by the open end of the first insulating liquid path (430) is arranged adjacent to both sides of the first electrode slurry slot (440). Accordingly, when the electrode slurry of the first manifold (110) is discharged, the insulating liquid is simultaneously discharged to the corner areas on both sides. In the dual slot die coater (10) of one embodiment illustrated in FIGS. 1 and 2, the first electrode slurry slots (440) are provided in two numbers, so that the electrode slurry of the first manifold (110) is discharged in two rows in parallel. Correspondingly, the first insulating liquid slots (450) are provided in four numbers. Similarly, the second insulating liquid slots (550) formed by the open ends of the second insulating liquid channels (530) are arranged adjacent to each other on both sides of the second electrode slurry slots (540).

[0065] FIG. 4 is a cross-sectional view taken along the line "AA" of FIG. 1. Referring to FIG. 4, the electrode slurry filled in the first manifold (110) of the first die block (100) is discharged through the first electrode slurry slot (440) formed thin and long toward the front surface (12) of the first die block (100) and the intermediate block (200). In addition, the electrode slurry filled in the second manifold (310) of the second die block (300) is discharged through the second electrode slurry slot (540) formed thin and long toward the front surface (12) of the second die block (300) and the intermediate block (200).

[0066] And, as shown in FIG. 4, the middle block (200) does not have a hollow portion for accommodating electrode slurry. Instead, as well shown in the "BB" cross-sectional view of FIG. 5, the middle block (200) has an insulating liquid supply passage (210) formed therethrough for supplying insulating liquid to the first insulating liquid passage (430) and the second insulating liquid passage (530), respectively. In one example, the insulating liquid supply passage (210) may include a main passage (212) extending transversely along the length of the middle block (200), and a branch passage (214) branched from the main passage (212) and extending vertically through the middle block (200). And, both ends of the branch passage (214) may be connected to the closed ends (inner ends) of the first insulating liquid passage (430) and the second insulating liquid passage (530), respectively.

[0067] In this way, the dual slot die coater (10) of the present invention can simplify the complex flow path structure of the dual slot die coater (10) that simultaneously discharges electrode slurry and insulating liquid by forming the insulating liquid supply flow path (210) in the middle block (200) structurally separated from the first and second manifolds (110, 310) on the first and second die blocks (100, 300). This simplified flow path structure not only reduces the manufacturing cost of the dual slot die coater (10), but is also advantageous in long-term maintenance.

[0068] And, as illustrated in FIGS. 3 and 5, the first insulating liquid passage (430) may be formed concavely on one surface of the first coater core (400) that is in close contact with the intermediate block (200), and the second insulating liquid passage (530) may be formed concavely on one surface of the second coater core (500) that is in close contact with the intermediate block (200). The insulating liquid is supplied to the closed ends of the first and second insulating liquid passages (430, 530) by penetrating the intermediate block (200), and the concave grooves of the first and second insulating liquid passages (430, 530) are discharged toward the surface that is in close contact with the intermediate block (200), so that the possibility of the insulating liquid being mixed into the electrode slurry inside the dual slot die coater (10) is structurally greatly reduced.

[0069] Meanwhile, in the dual slot die coater (10) of the present invention, the coater shims (400, 500) may be a one-piece structure, but may also be formed as a two-piece structure of a body shim (410, 510) and a spacer shim (420, 520) as shown in the drawing. That is, the first coater shim (400) may include a first body shim (410) that surrounds both sides and the rear surface of the first manifold (110), and a plurality of first spacer shims (420) spaced apart from each other so as to cross toward the front surface (12) of the first manifold (110). Here, a first insulating liquid path (430) is formed on the surfaces of the plurality of first spacer shims (420). Similarly, the second coater core (500) may include a second body core (510) and a plurality of second spacer cores (520).

[0070] 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) for discharging the electrode slurry. By configuring one coater shim (400, 500) as a two-piece structure of the body shim (410, 510) and the spacer shim (420, 520), only the spacer shim (420, 520) can be replaced instead of replacing the entire coater shim (400, 500), which is efficient in terms of maintenance effort and cost.

[0071]

[0072] [Second Embodiment]

[0073] In the second embodiment, an embodiment is described in which an insulating liquid is supplied to a first insulating liquid passage (430) and a second insulating liquid passage (530) through an insulating liquid supply passage (210) formed through a middle block (200).

[0074] Fig. 6 illustrates a structure in which one of the open ends of the main passage (212) penetrating transversely along the length of the intermediate block (200) is configured as an insulating liquid inlet (220), and the other end is closed. Since one end of the main passage (212) is closed, the main passage (212) is pressurized and filled with the insulating liquid supplied to the insulating liquid inlet (220), and a portion of the filled insulating liquid is supplied to the first insulating liquid passage (430) and the second insulating liquid passage (530) through the branch passage (214) and discharged to the first insulating liquid slot (450) and the second insulating liquid slot (550).

[0075] Fig. 7 illustrates a structure in which both open ends of the main passage (212) penetrating laterally along the length of the intermediate block (200) are configured as insulating liquid inlets (220). In the embodiment of Fig. 6, when the lateral length of the dual slot die coater (10) is long, the flow rate of the insulating liquid supplied to the first insulating liquid passage (430) and the second insulating liquid passage (530) decreases as the distance from the insulating liquid inlet (220) increases, and accordingly, the difference in the amount of insulating liquid discharged from the plurality of first insulating liquid slots (450) and second insulating liquid slots (550) may increase.

[0076] Fig. 7 is a configuration for reducing the variation in the amount of insulating liquid discharged, in which the insulating liquid is supplied to both sides of the main path (212). By supplying the insulating liquid from both sides of the horizontal length of the dual slot die coater (10), the variation in the amount of insulating liquid discharged in the entire first insulating liquid slot (450) and the second insulating liquid slot (550) can be reduced.

[0077]

[0078] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may be substituted for them at the time of filing this application.

Claims

1. A first die block having a first manifold for receiving electrode slurry; An intermediate block coupled with the first die block; A first coater shim that surrounds both sides and the rear surface of the first manifold, and is interposed between the first die block and the middle block to form a first electrode slurry slot for discharging electrode slurry filled in the first manifold; A second die block having a second manifold for receiving electrode slurry and coupled to the intermediate block; and A second coater core that surrounds both sides and the rear surface of the second manifold, and is interposed between the second die block and the middle block to form a second electrode slurry slot for discharging electrode slurry filled in the second manifold; Including, The first coater core and the second coater core have a first insulating liquid path and a second insulating liquid path that form a first insulating liquid slot and a second insulating liquid slot for discharging the insulating liquid, respectively. A dual slot die coater, wherein an insulating liquid supply path for supplying insulating liquid to the first insulating liquid path and the second insulating liquid path is formed by penetrating the intermediate block.

2. In paragraph 1, The above insulating liquid supply path is: A main passage that runs transversely along the length of the above intermediate block, A dual slot die coater, comprising a branch path branching from the main path and penetrating the intermediate block in an upward and downward direction.

3. In paragraph 2, The two ends of the above quarterly euro are, A dual slot die coater, each connected to the closed end of the first insulating liquid path and the second insulating liquid path.

4. In paragraph 3, The above first insulating fluid path is, A dual slot die coater, wherein one side surface of the first coater core is concavely formed in close contact with the intermediate block.

5. In paragraph 4, The above second insulating fluid path is, A dual slot die coater, wherein one side surface of the second coater core is concavely formed in close contact with the intermediate block.

6. In any one of paragraphs 1 to 5, The above first coater core, A first body core having a shape that surrounds both sides and the rear of the first manifold, A dual slot die coater comprising a plurality of first spacer cores spaced apart from each other between the first body cores so as to extend across the front of the first manifold, and having the first insulating liquid path formed on the surface thereof.

7. In paragraph 6, The above second coater core, A second body core having a shape that surrounds both sides and the rear of the second manifold, A dual slot die coater comprising a plurality of second spacer cores spaced apart from each other between the second body cores so as to extend across the front of the second manifold, and having the second insulating fluid path formed on the surface thereof.

8. In any one of paragraphs 2 to 5, The above main euro is, A dual slot die coater with one end being an insulating liquid inlet and the other end being closed.

9. In any one of paragraphs 2 to 5, The above main euro is, Dual slot die coater with insulating liquid inlets at both ends.

10. In paragraph 1, A dual slot die coater, wherein the electrode slurry filled in each of the first manifold and the second manifold is a different electrode slurry that is distinct from each other.

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