Slot die shim and slot die comprising the same

Abstract

The present invention relates to a slot die shim disposed between a first slot die and a second slot die, wherein a plurality of protrusions separate a flow path for a slurry into a plurality of channels, the slot die shim comprising: a coupling portion coupled to the first and second slot dies; a plurality of first protrusions spaced apart from each other and included protruding from one side of the coupling portion, and one or more second protrusions positioned between the first protrusions, wherein the second protrusions include a groove through which the slurry flows.

Description

Technology Field

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2021-0174948 filed with the Korean Intellectual Property Office on December 8, 2021, the entire contents of which are incorporated herein.

[0002] The present invention relates to a slot die shim and a slot die including the same. Specifically, the present invention relates to a slot die shim that reduces the slurry supply flow rate at the end of an electrode slurry application portion and a slot die including the same. Background Technology

[0003] Recently, the demand for eco-friendly alternative energy sources has been increasing due to rising energy prices caused by the depletion of fossil fuels and growing concerns about environmental pollution. Accordingly, research on various power generation technologies, such as nuclear, solar, wind, and tidal power, is continuing, and there is also significant interest in power storage devices to utilize this generated energy more efficiently.

[0004] In particular, as technological development and demand for mobile devices increase, the demand for batteries as an energy source is rapidly rising. Much research is being conducted on batteries capable of meeting this demand.

[0005] In terms of battery shape, there is high demand for prismatic and pouch-type rechargeable batteries, which feature thin profiles and can be applied to products such as mobile phones. In terms of materials, there is high demand for lithium-ion rechargeable batteries, such as lithium-ion batteries and lithium-ion polymer batteries, which possess advantages including high energy density, discharge voltage, and output stability.

[0006] Generally, a secondary battery has a structure comprising an electrode assembly having a stacked structure of a positive electrode, a negative electrode, and a separator located between the positive and negative electrodes. The positive and negative electrodes are manufactured by coating an electrode slurry containing an active material onto a current collector.

[0007] A die coater can be used to coat an electrode slurry containing an active material onto a current collector. The die coater is a device that uses a pulsation-free pump or a piston pump to supply a fluid, such as an electrode slurry, adhesive, hard coating agent, ceramic, etc., between processed upper and lower dies, and coats a workpiece such as a raw material, film, glass plate, or sheet with a uniform thickness.

[0008] FIG. 1(a) is a front view of a conventional slot die core and a side view of a substrate (3) on which an electrode slurry (4) is applied using the same, and FIG. 1(b) is a drawing showing the application of an electrode slurry (4) onto a substrate (3) using a conventional slot die.

[0009] A slot die used in the manufacture of electrodes applies an electrode slurry (4) to a substrate in a long, continuous direction. In order to form an outlet through which the electrode slurry (4) is discharged, a slot die shim is generally placed between two dies in the slot die. The slot die may have two or more dies, and a slot die shim is provided between each of the two or more dies, and the shapes of the shims may differ from each other.

[0010] As electrode shapes become more diverse, research on die coater shims suitable for them is also necessary. Prior art literature

[0011] Korean Registered Publication No. 10-0551039 The problem to be solved

[0012] Based on the problems of the aforementioned prior art, the present invention aims to provide a slot die shim that uniformly controls the amount of electrode slurry in a coating portion where electrode slurry is applied, and a slot die including the same. means of solving the problem

[0013] One embodiment of the present invention provides a slot die shim disposed between a first slot die and a second slot die, wherein the slurry flow path is separated into a plurality of channels by a plurality of protrusions, the slot die shim comprises: a coupling portion coupled to the first and second slot dies; a plurality of first protrusions positioned spaced apart from each other and protruding from one side of the coupling portion, and one or more second protrusions positioned between the first protrusions, wherein the second protrusions include a groove through which the slurry flows.

[0014] One embodiment of the present invention provides a slot die comprising: a first slot die; a second slot die and a slot die shim, wherein either of the first and second slot dies comprises a supply unit for supplying a slurry and a storage unit for storing the slurry. Effects of the invention

[0015] A slot die shim according to an embodiment of the present invention and a slot die including the same can uniformly control the amount of electrode slurry in the coating portion where the electrode slurry is applied, thereby preventing the formation of a sliding section at the end of the coating portion and reducing the change in the discharge capacity ratio of a secondary battery. Brief explanation of the drawing

[0016] FIG. 1(a) is a front view of a conventional slot die core and a side view of a substrate coated with electrode slurry using the same, and FIG. 1(b) is a drawing showing the application of electrode slurry onto a substrate using a conventional slot die. FIG. 2 is a front view of a slot die shim according to one embodiment of the present specification and a side view of a substrate coated with an electrode slurry using the same. FIG. 3 is a perspective view of a slot die shim according to another embodiment of the present invention. FIG. 4 is a perspective view of a slot die shim according to another embodiment of the present invention. FIG. 5 is an assembly drawing of a slot die according to one embodiment of the present specification and a cross-sectional view of CC', and (a) to (c) illustrate the change in cross-section according to the length of the guide of the shim for the die coater in the cross-sectional view of CC'. FIG. 6 is a perspective view illustrating a slot die including a slot die core according to another embodiment of the present invention. FIG. 7 is a perspective view and a partial enlarged view of a slot die including a slot die shim according to another embodiment of the present specification. FIG. 8 is a drawing corresponding to a graph measuring the step difference of an electrode slurry applied to a slot die according to one embodiment of the present specification, the shape of a recess, and a cross-sectional view of a second protrusion. FIG. 9 is an exploded view of an electrode assembly manufactured using a slot die according to one embodiment of the present invention. Specific details for implementing the invention

[0017] The detailed description of the present invention is intended to fully explain the invention to those skilled in the art. Throughout the specification, when a part is described as "comprising" a certain component or "featuring" a certain structure and shape, unless specifically stated otherwise, this does not mean that other components are excluded or other structures and shapes are excluded, but rather that other components, structures, and shapes may be included.

[0018] The present invention is capable of various modifications and may have various embodiments, and specific embodiments are presented and described in detail in the detailed description. However, this is not intended to limit the scope of the invention by the embodiments, and it should be understood that it includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0019] The present invention will be described in detail below with reference to the drawings. However, the drawings are intended to illustrate the invention, and the scope of the invention is not limited by the drawings.

[0021] FIG. 2 is a front view of a slot die core (10) according to one embodiment of the present specification and a side view of a substrate (3) on which an electrode slurry (4) is applied using the same, FIG. 5 is an assembly view of a slot die (100) according to one embodiment of the present specification and a CC' cross-sectional view, and (a) to (c) illustrate the change in the cross-section according to the length of the guide of the die coater core in the CC' cross-sectional view. FIG. 7 is a perspective view and a partial enlarged view of a slot die (100) including a slot die core (10) according to another embodiment of the present specification.

[0022] A slot die (100) may include a slot die core (10), a first die (20), and a second die (30) by applying an electrode slurry (4) to one surface of a substrate. The slot die (100) may have a slot die core (10) positioned between the first and second dies (20, 30). Additionally, the slot die core (10) may be provided in a plate-like structure.

[0023] At this time, the substrate is not specifically limited as long as it can be coated with the electrode slurry, but the substrate may be an electrode current collector, specifically a metal foil, or a foil made of a material that is a combination of copper, aluminum, PET.

[0024] An electrode slurry can be prepared by supplying and mixing an electrode active material, a conductive material, a binder, and a solvent. The electrode active material may include either a positive electrode active material or a negative electrode active material, and preferably may include a positive electrode active material. The positive electrode active material may include lithium ions.

[0025] The conductive material can increase the conductivity of the electrode active material, and the solvent can control the viscosity of the electrode slurry.

[0026] The binder can physically stabilize the electrode. The binder can increase the adhesion between the electrode active material and the conductive material to a sheet (current collector), for example, an aluminum sheet or a copper sheet, to which the electrode slurry is applied in a subsequent process.

[0027] Various electrode active materials, conductive materials, binders, and solvents used in the relevant technical field may be used, and their types are not particularly limited.

[0028] The slot die shim (10) may include a coupling portion (11), a first protrusion (12), and a second protrusion (13). The slot die shim (10) may have a plurality of flow paths (14) through which the electrode slurry (4) flows separated by the first and second protrusions (12, 13).

[0029] The connecting portion (11) can connect the first and second dies (20, 30) and the slot die shim (10). Accordingly, the connecting portion (11) may include a plurality of fastening grooves (not shown). The fastening grooves penetrate along the thickness direction (y) of the connecting portion (11) and can be fastened and fixed with bolts, etc., to the fastening grooves included in the first and second dies (20, 30). Also, the fastening grooves may be arranged along the width direction (x) of the connecting portion (11).

[0030] The first protrusion (12) is included by protruding from one side of the coupling part (11), and a plurality of them may be positioned spaced apart from each other. The first protrusion (12) may extend along the electrode slurry flow direction from one side of the coupling part (11).

[0031] The slot die shim (10) according to the present invention may be provided with a flow path (14) through which an electrode slurry (4) is supplied by a first protrusion (12). That is, the electrode slurry (4) may be supplied into the space between a plurality of first protrusions (12) of the slot die shim (10) so that the electrode slurry (4) can be applied to one surface of the substrate, and the electrode slurry (4) may not be applied to the area where the first protrusion (12) is located.

[0032] That is, the flow path (14) provided by the first protrusion (12) may be provided in a structure that is open in a direction horizontal to the plane where the coupling part (11) and the first and second dies (20, 30) come into contact. In other words, the flow path (14) may be provided in a structure that is open only in the direction of flow of the electrode slurry (4), and may be provided in a structure where three sides are closed by the coupling part (11) and the second protrusion (12).

[0033] A slot die (100) according to the present invention may include a coating portion (not shown) on one surface of a substrate (3) where an electrode slurry (4) is applied, and an uncoated portion (not shown) where the electrode slurry (4) is not applied by a first protrusion (12). The uncoated portion may be a slot die core (10) region where the first protrusion (12) is located.

[0034] The second protrusion (13) is located between a plurality of first protrusions (12) and may include one or more. In this specification, "one or more" may mean including one or two or more multiple protrusions.

[0035] Referring to FIG. 2, a slot die core (10) according to one embodiment of the present invention includes one second protrusion (13), and thus, an electrode formed by a slot die (100) according to one embodiment can have one semi-coated portion formed.

[0036] And, if the slot die core (10) includes two second protrusions (13), the electrode formed by the slot die (100) equipped with the slot die core (10) including two protrusions (13) can have two semi-coated portions formed.

[0037] Referring to FIG. 7, a slot die (100) including a slot die core (10) including three second protrusions (13) can manufacture an electrode with three semi-coated portions formed.

[0038] When a single set of protrusions is provided on the slot die shim (10), the second protrusion (13) may be positioned between a pair of first guides (12a). And when two or more sets of protrusions are provided on the slot die shim (10), multiple second protrusions (13) may be included and may be positioned between the first guide (12a) and the second guide (12b).

[0039] The enlarged view of the second protrusion (13) shown in FIG. 7 is a drawing that enlarges a portion of the second protrusion (13) in the direction from the second die (30) to the first die (20). Referring to FIG. 7, the second protrusion (13) may include a groove (13a) through which the electrode slurry flows. The groove (13a) may be included inside the second protrusion (13) and may be provided in a form with one side open. The opening of the groove (13a) may be provided in the direction in which the second die (13) containing the supply hole (1) is located.

[0040] For example, the groove (13a) may be open in a portion of the plane that contacts the first die (20) or the second die (30) equipped with the second protrusion (13) and the supply hole (1). That is, the groove (13a) may be provided with a structure in which three sides are closed except for the direction in which the electrode slurry is supplied and flowed by the inner wall of the second protrusion (13). Also, the groove (13a) may be open along the longitudinal direction (z) of the second protrusion (13).

[0041] Accordingly, the second protrusion (13) can apply a smaller amount of electrode slurry to one surface of the substrate than the coated portion where the electrode slurry is applied by the flow path (14), and can form a semi-coated portion (not shown).

[0042] Referring to FIG. 5(a), the other end of the second protrusion (13) may be located on the same line as the end of each lip (21, 31) of the first and second dies (20, 30).

[0043] Referring to FIG. 5(b), the other end of the second protrusion (13) may be located outside the slot die (100) compared to the ends of the respective lip (21, 31) of the first and second dies (20, 30). When provided in this manner, the slot die shim (10) may protrude outward. At this time, the other end of the second protrusion (13) may protrude more than 0 mm and less than or equal to 0.3 mm from the end of the lip, and the protruding other end of the second protrusion (13) protrudes to a level that does not come into contact with the substrate to be coated. Specifically, the difference between the other end of the second protrusion (13) and the end of the lip (21, 31) is smaller than the distance between the end of the lip (21, 31) and the substrate.

[0044] As shown in FIG. 5(b), when the second protrusion (13) provided in the slot die shim (10) protrudes outward, the pressure loss of the bead discharged through the groove (13a) of the second protrusion (13) increases, thereby reducing the difference in width between the discharge width and the coating width. Accordingly, as the length of the second protrusion (13) protruding outward increases, the part where the step difference changes, that is, the part where the coating amount changes, in other words, the area of ​​FIG. 8 b where the coating amount gradually decreases or increases, becomes narrower.

[0045] Referring to FIG. 5(c), the other end of the second protrusion (13) may be located inside the slot die, rather than the end of each lip (21, 31) of the first and second dies (20, 30). When provided in this way, the slot die shim (10) may not protrude outward.

[0046] FIG. 8 is a graph measuring the step difference of an electrode slurry coated with a slot die (100) according to one embodiment of the present specification, and a cross-sectional view of the shape of the semi-coated portion and the second protrusion (13), and FIG. 9 is an exploded view of an electrode assembly manufactured using a slot die (100) according to one embodiment of the present invention.

[0047] An electrode (or a first electrode) manufactured by a slot die (100) according to the present invention includes a semi-coated portion formed by a second protrusion (13), and the semi-coated portion may face a sliding portion of another electrode (a second electrode). For example, an anode manufactured by a slot die (100) according to the present invention includes a semi-coated portion at its end, and the semi-coated portion of the anode may face a sliding portion provided at the end of the cathode.

[0048] At this time, the semi-coated section may be provided with a shape opposite to that of the sliding section. Referring to FIG. 9, the amount of electrode slurry in the sliding section of the cathode gradually decreases as it approaches the end of the sliding section, and in the semi-coated section of the anode, the decrease in the amount of electrode slurry applied is large at the beginning, but as it approaches the end of the semi-coated section, the amount of electrode slurry or the thickness of the semi-coated section may become constant. Accordingly, the slot die shim (10) according to the present invention can maintain the ratio of anode and cathode electrode slurry in the cathode and anode electrode slurry coating section and the ratio of electrode slurry in the sliding section of the cathode and the semi-coated section of the anode identically.

[0049] That is, the slot die shim (10) according to the present invention can reduce the amount of positive electrode slurry in accordance with the amount of negative electrode slurry in the negative electrode sliding section to maintain the same ratio of the electrode slurry or the amount of electrode active material in the entire active material coating section, and by reducing the amount of positive electrode slurry in accordance with the reduced amount of negative electrode slurry, the discharge capacity ratio can be maintained constant.

[0050] In addition, as the amount of electrode slurry in the anode semi-coated portion is reduced according to the cathode sliding area, the discharge capacity of the anode can be provided to be smaller than the discharge capacity of the cathode, and accordingly, the effect of reducing lithium deposition and increasing the stability of the cell can occur.

[0051] The groove (13a) may have a height (h) of 0.1 mm to 10 mm, and preferably, the groove (13a) may have a height (h) of 0.1 mm to 3 mm. Also, the volume of the groove (13a) may be 0.1 volume% to 80 volume% based on the volume of the flow path (14) provided by the first and second protrusions (12, 13), and preferably, the volume of the groove (13a) may be 0.1 volume% to 60 volume% based on the volume of the flow path (14) provided by the first and second protrusions (12, 13).

[0052] Alternatively, the amount of electrode slurry supplied to the second protrusion (13) may be 0.1% to 80% based on the amount of electrode slurry supplied through the first and second protrusions (12, 13). That is, the amount of electrode slurry supplied through the groove (13a) may be 0.1% to 80% based on the amount of electrode slurry supplied through the channel (14).

[0053] If the height (T2) of the groove (13a) is less than 0.1 mm and the volume is less than 0.1%, the amount of electrode slurry applied to the semi-coated portion is small, which may cause a problem in which the total capacity of the secondary battery is reduced. Also, if the height of the groove (13a) exceeds 3 mm and the volume exceeds 60%, the amount of electrode slurry applied to the semi-coated portion increases, and the ratio of lithium forming a surface film increases, which may reduce the stability of the cell.

[0054] Referring to FIG. 8, the height of the semi-coated portion can be adjusted by the difference (T1-T2) between the thickness (T1) of the slot die core (10) and the height (T2) of the groove (13a). Specifically, the height of H3 in FIG. 2 or the depth of a in FIG. 8 can be adjusted by the difference (T1-T2) between the thickness (T1) of the slot die core (10) and the height (T2) of the groove (13a).

[0055] The width of the side wall of the groove (13a) having the same thickness (T1) as the slot die core (10) among the second protrusions (13) affects the slope of region b, where the step difference changes in the pattern of the electrode slurry. Region c is a region where the step difference does not change in the pattern and is a region with a depth of a.

[0057] The first and second dies (20, 30) may be located at the upper and lower portions of the slot die core (10). Here, the upper and lower portions of the slot die core (10) may refer to directions perpendicular to the supply direction of the electrode slurry.

[0058] The first and second dies (20, 30) have mutually symmetrical truncated pyramid shapes, and one surface of the first and second dies (20, 30) corresponding to the base of the truncated pyramid is assembled facing each other. At this time, it is preferable that one surface of the first and second dies (20, 30) surrounds the outer surface of the slot die core (10) and is larger than one surface of the slot die core (10).

[0059] At least one of the first and second dies (20, 30) has a supply hole (1) formed therein for receiving electrode slurry from the outside. The electrode slurry supplied from the outside through the supply hole (1) is stored in an internal space (2) formed inside at least one of the first and second dies (20, 30).

[0060] A slot die shim (10) is placed between the first and second dies (20, 30). Accordingly, the first and second dies (20, 30) are spaced apart from each other by the thickness of the slot die shim (10), so that a flow path (14) is formed inside the slot die (100). The electrode slurry stored in the internal space (2) flows inside the slot die (100) along the flow path (14) and is discharged to the outside through a discharge port (not shown). This discharge port is formed thin and long, and as the slot die (100) moves at a constant speed on the substrate, the electrode slurry can be applied broadly and uniformly to the substrate.

[0062] FIG. 3 is a perspective view of a slot die core (10) according to another embodiment of the present invention, FIG. 4 is a perspective view of a slot die core (10) according to yet another embodiment of the present invention, and FIG. 6 is a perspective view showing a slot die (100) including a slot die core (10) according to another embodiment of the present invention.

[0063] The first protrusion (12) may include a first guide (12a) which is positioned at each end of the coupling portion (11) and extends in the flow direction of the electrode slurry (4), and a second guide portion (12b) which is positioned between the first guide portion (12a) and extends in the flow direction of the electrode slurry. The first and second guides (12a, 12b) may form an uncoated portion, and the uncoated portion may become an electrode tab and may be coupled with an electrode lead.

[0064] A slot die shim (10) according to another embodiment of the present invention may include a set of protrusions (not shown) comprising a pair of first guides (12a) and second protrusions (13).

[0065] The first guide (12a) may be included as a pair, positioned at each end of the coupling portion (11). Additionally, the first guide (12a) may be provided extending along the flow direction of the electrode slurry, or the end of the electrode slurry flow direction may be provided bent in a direction perpendicular to the flow direction of the electrode slurry. That is, the first guide (12a) may include only an extension portion (12a-1) extended along the flow direction of the electrode slurry, or it may include an extension portion (12a-1) and a bent portion (12a-2) located at the end of the extension portion (12a-1) and extended in a direction perpendicular to the flow direction of the electrode slurry.

[0066] The bending portion (12a-2) may be included in at least one of a pair of first guides (12a). That is, the first protrusion (12) may include a first guide (12a) that includes both the extension portion (12a-1) and the bending portion (12a-2), and a first guide portion (12a) that includes only the extension portion (12a-1), or may include a pair of first guide portions (12a) that include both the extension portion (12a-1) and the bending portion (12a-2).

[0067] The first guide (12a) may be provided with a step (12c) at the end portion, that is, at the end portion of the extension portion (12a-1) or the end portion of the bend portion (12a-2). In this specification, the end portion may refer to the edge of the end portion of the configuration.

[0068] In the slot die shim (10), the amount of electrode slurry supplied to both edges of the coating portion, that is, both ends of the coating portion, can be reduced by the end step (12c) of the first guide (12a). Also, in the slot die shim (10), friction occurs between the electrode slurry supplied to the flow path (14) and the first protrusion (12), thereby reducing the amount of flow and forming a sliding section formed at the edge of the coating portion.

[0069] The end portion (12c) provided in the first guide (12a) reduces the amount of electrode slurry supplied to the sliding section, thereby stopping the supply of electrode slurry to the edge of the coating section by the frictional force with the first guide (12a) and the end portion (12c). Accordingly, the sliding section of the coating section is not formed, so the electrode slurry is uniformly discharged to the edge portion and the center portion of the coating section, thereby reducing the variation in thickness.

[0070] The step (12c) may be provided with a size of 0.5 mm to 15 mm in the direction of flow of the electrode slurry and 0.1 mm to 5 mm in the direction perpendicular to the direction of flow of the electrode slurry. Preferably, the step (12c) may be provided with a size of 1 mm to 10 mm in the direction of flow of the electrode slurry and 0.1 mm to 1 mm in the direction perpendicular to the direction of flow of the electrode slurry.

[0071] If the step (12c) is formed with a size of less than 1 mm in the direction of flow of the electrode slurry and less than 0.1 mm in the direction perpendicular to the direction of flow of the electrode slurry, a sliding section is formed at the end of the coating portion, and a problem may occur in which the electrode product has a thickness variation. Also, if the step (12c) is formed with a size of more than 10 mm in the direction of flow of the electrode slurry and more than 1 mm in the direction perpendicular to the direction of flow of the electrode slurry, the electrode slurry is coated up to the uncoated portion formed by the first guide (12a), and a problem may occur in which the electrode tab is not formed.

[0072] Referring to FIG. 4, a slot die shim (10) according to another embodiment of the present invention may include a plurality of protrusion sets, and the slot die shim (10) including a plurality of protrusion sets may be provided with a second guide (12b).

[0073] The slot die shim (10) may include a second guide (12b) between a pair of first guides (12a). The second guide (12b) may be provided with steps (12c) at both ends to prevent the formation of a sliding section of the edge portion of the coating portion, as with the first guide (12a). In other words, the second guide (12b) may be provided with steps (12c) at the corners located at positions facing each other.

[0074] And, the uncoated portion formed by the second guide (12b) can be slit in the middle to form two sheet-shaped electrodes.

[0076] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and changes can be made to the invention without departing from the spirit and scope of the invention as described in the following claims. Explanation of the symbols

[0077] 100: Slot Die 10: Slot die shim 11: Joint 12: First protrusion 12a: First Guide 12a-1: Extension part 12a-2: Bending section 12b: Second Guide 12c: Step 13: Second protrusion 13a: Home 14: Euro 20: The first die 21: The 1st Lip 30: The Second Die 31: The 2nd Lip 1: Supply hole 2: Interior space 3: Entry 4: Electrode slurry

Claims

Claim 1 A slot die shim disposed between a first die and a second die, wherein the electrode slurry flow path is separated into multiple paths by multiple protrusions, the slot die shim comprises: a coupling portion coupled to the first and second dies; a first protrusion protruding from one side of the coupling portion and positioned such that two or more are spaced apart from each other, and one or more second protrusions positioned between the first protrusions, wherein the second protrusions include a groove through which the electrode slurry flows, and the grooves are closed on three sides except for the direction in which the electrode slurry is supplied and flows by the inner wall of the second protrusions, and the second protrusions coat one surface of a substrate with an amount of electrode slurry less than the amount of electrode slurry flowing through the paths. Claim 2 delete Claim 3 delete Claim 4 A slot die shim according to claim 1, wherein the height of the groove is 0.1 mm to 3 mm. Claim 5 A slot die shim according to claim 1, wherein the volume of the groove is 0.1 volume% to 80 volume% based on the volume of the flow path provided between the first and second protrusions. Claim 6 A slot die shim according to claim 1, wherein the first protrusion is located at both ends of the coupling portion and includes two or more first guides extending in a horizontal direction of the plane where the coupling portion and the first and second dies contact, and a second guide located between the two or more first guides and extending in a direction horizontal to the direction in which the first guides extend, and the second protrusion is located between the first guides and the second guides. Claim 7 A slot die shim according to claim 6, wherein at least one end of the first guide is bent in the direction in which the second guide is located. Claim 8 A slot die shim according to either claim 6 or 7, wherein the first guide is provided with a step at at least one corner. Claim 9 A slot die shim according to claim 8, wherein the step is provided at the outer edge of the two corners of the first guide. Claim 10 A slot die shim according to claim 6, wherein the second guide has a step formed at mutually opposing edges. Claim 11 A slot die shim according to claim 1, wherein the fluid path is open in the horizontal direction of the plane where the coupling part and the first and second dies contact, and has a structure in which three sides excluding the open direction are closed. Claim 12 A slot die according to claim 1, comprising two or more dies having a lip at one end and a slot die core configured to discharge an electrode slurry between the two or more lip provided on each of the two or more dies, wherein the slot die core comprises a coupling portion extending in the width direction of the die and coupled with the two or more dies, a plurality of first protrusions protruding from one side of the coupling portion and positioned spaced apart from each other, and a second protrusion positioned between the first protrusions and having a groove recessed inward. Claim 13 A slot die according to claim 12, wherein the other end of the second protrusion is located outside the slot die compared to the end of the lip. Claim 14 A slot die according to claim 12, wherein the other end of the second protrusion is located on the same line as the end of the lip. Claim 15 A slot die according to claim 12, wherein the other end of the second protrusion is located inside the slot die rather than the end of the lip.

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