Slit die coater and electrode for secondary battery

Abstract

A slit die coater includes: a first die block; a second mold block on the first mold block, the second mold block having a first chamber configured to receive a mixture; a first slit between the first mold block and the second mold block; a third mold block on the second mold block, the third mold block having a second chamber configured to contain the slurry; a second slit between the third mold block and the second mold block; a first spacer in the first slit, the first spacer including an inner region connecting the first slit to the first discharge port and a shield protrusion protruding from the inner region toward the first discharge port, the first discharge port setting a width at which the mixture is discharged and applied from the first discharge port; and a second spacer in the second slit, the second spacer including a notch connecting the second slit to the second discharge port, and the second discharge port overlapping a portion of an edge portion of the first discharge port.

Description

Technical Field

[0001] An aspect of the embodiments of this disclosure relates to a slot die coating machine and electrodes for secondary batteries. Background Technology

[0002] Unlike primary batteries, which are not designed to be (re)charged, secondary (or rechargeable) batteries are designed to be discharged and recharged. Low-capacity secondary batteries are used in portable small electronic devices such as smartphones, feature phones, laptops, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources to drive motors in hybrid and electric vehicles and for storing electricity (e.g., household and / or utility-scale power storage). A secondary battery typically includes an electrode assembly containing positive and negative electrodes, a housing that houses the electrode assembly, and electrode terminals connected to the electrode assembly.

[0003] Slot die coating technology is a key technology in the manufacturing process of rechargeable batteries, used to uniformly coat active material slurry onto the electrode substrate. Slot die coating machines can precisely control the viscosity and coating thickness of the slurry. Therefore, slot die coating machines can be used to stably produce high-quality electrodes. In the slot die coating process, the slurry applied through the slots of the slot die can be uniformly distributed on the substrate. As a result, this uniform coating directly affects the battery's performance and lifespan.

[0004] In the production of electrodes for secondary batteries, slot die coating offers higher precision and consistency than roller coating, and has the advantage of minimizing material waste. In other examples, slot die coaters are capable of producing electrodes of varying thicknesses by controlling their process speed, making them suitable for high-volume production. Slot die coaters have a structure with high mechanical stability and can precisely coat various substrates based on the flow characteristics of the slurry.

[0005] The information disclosed in this background section is intended to enhance the understanding of the background art of this disclosure, and therefore may contain information that does not constitute related (or prior art). Summary of the Invention

[0006] According to one or more embodiments of this disclosure, a slot die coating machine includes: a first die block; a second die block on the first die block, the second die block having a first chamber configured to receive a mixture; a first slot between the first die block and the second die block; and a third die block on the second die block, the third die block having a function to receive a barrier slurry. The first slit comprises a second chamber for the slurry; a second slit between the third mold block and the second mold block; a first separator located in the first slit; and a second separator located in the second slit; wherein the first separator comprises an internal region connecting the first slit to the first discharge port and a shielding protrusion protruding from the internal region toward the first discharge port, the first discharge port being used to set the width of the mixture discharged from the first discharge port and applied to the substrate through the first discharge port (or to determine the width of the applied mixture layer when the mixture is discharged through the first discharge port connected to the first slit and applied to the substrate); and wherein the second separator comprises a notch connecting the second slit to the second discharge port, the second discharge port overlapping at least a portion of the edge portion of the first discharge port (or guiding the blocking slurry to overlap at least a portion of the edge portion of the applied mixture layer when the blocking slurry is discharged through the second discharge port connected to the second slit).

[0007] In one embodiment, the shielding protrusion may be located in the center of the interior of the first barrier, and the shielding protrusion may be separated from the first discharge port.

[0008] In an embodiment, the shielding protrusion may include a central portion protruding toward the first discharge port and inclined sections symmetrical to each other with respect to the centerline of the shielding protrusion, the inclined sections being located on both sides of the central portion.

[0009] In an embodiment, the first separator may further include a base portion and a plurality of extension portions extending from one side of the base portion toward the first discharge port, and the shielding protrusion may protrude from the base portion toward the first discharge port and may be located between the plurality of extension portions.

[0010] In one embodiment, the ends of two of the extensions located at both ends (or opposite ends) of the first spacer may be bent toward the center of the first spacer.

[0011] In an embodiment, at least a portion of the end of one of the extensions located between two extensions at both ends (or opposite ends) of the first separator may be bent toward at least one of the two extensions.

[0012] In an embodiment, the shielding protrusion may be located between two adjacent extensions among a plurality of extensions.

[0013] In an embodiment, the second discharge port may overlap at least a portion of both ends (or opposite ends) of the first discharge port.

[0014] In one embodiment, the first slit may be located above the second slit.

[0015] In an embodiment, the first slit may extend horizontally between the first mold block and the second mold block (or be formed horizontally between the first mold block and the second mold block), and the second slit may extend between the second mold block and the third mold block at an angle relative to the first slit (or be formed obliquely between the second mold block and the third mold block), so that it is closer to the first slit the closer it is to the second discharge port.

[0016] In this embodiment, the distance between the first discharge port and the second discharge port in the thickness direction can be 0.

[0017] In an embodiment, the blocking slurry may comprise a water-soluble polymer.

[0018] In the embodiments, the water-soluble polymer may contain carboxymethyl cellulose salt.

[0019] In an embodiment, the second separator may include a plurality of recesses opening toward the second discharge port, the recesses being positioned to correspond to edge portions of the mixture (or the layer of mixture applied) to the substrate through the first discharge port.

[0020] In an embodiment, the plurality of notches may extend in a direction away from the orientation of the second discharge port (or in a direction opposite to the orientation of the second discharge port).

[0021] According to one or more embodiments of the present disclosure, an electrode for a secondary battery includes: a substrate; a coating mixture layer on the substrate, the coating mixture layer comprising a mixture discharged through a first slit of a slit mold coating machine as described above (or formed by coating the mixture discharged through the first slit of a slit mold coating machine as described above onto the substrate); a barrier film on the substrate, the barrier film being at opposite ends of the coating mixture layer, the barrier film comprising a barrier slurry discharged through a second slit of a slit mold coating machine (or formed at both ends of the coating mixture layer by coating the barrier slurry discharged through the second slit of a slit mold coating machine onto the substrate).

[0022] In an embodiment, the maximum thickness of the barrier film on the substrate may be less than the maximum thickness of the coating mixture layer.

[0023] In one embodiment, the barrier membrane can be formed by removing moisture from the barrier slurry.

[0024] In an embodiment, the viscosity of the blocking slurry can be equal to or greater than the viscosity of the mixture.

[0025] In the embodiments, the mixture may include electrode active material, conductive material and binder. Attached Figure Description

[0026] The accompanying drawings illustrate embodiments of the present disclosure and, together with the detailed description of the present disclosure, further describe aspects and features of the present disclosure. Therefore, the present disclosure should not be construed as limited to the drawings:

[0027] Figure 1 This is a perspective view illustrating a slot die coating machine and a substrate according to some embodiments of the present disclosure;

[0028] Figure 2 It is along Figure 1 A cross-sectional view of line AA';

[0029] Figure 3 This is an exploded perspective view illustrating a slot die coating machine according to some embodiments of the present disclosure;

[0030] Figure 4 This is a diagram schematically illustrating a first isolator according to some embodiments of the present disclosure;

[0031] Figure 5 This is a schematic diagram of a first spacer according to some embodiments of the present disclosure;

[0032] Figure 6 This is a schematic diagram of a first spacer according to some embodiments of the present disclosure;

[0033] Figure 7 and Figure 8 This is a schematic diagram of a second spacer according to some embodiments of the present disclosure;

[0034] Figure 9 This is a diagram used to explain the effects obtained by a slot die coating machine according to some embodiments of this disclosure;

[0035] Figure 10 This is a schematic diagram illustrating the cross-section of an electrode for a secondary battery according to some embodiments of the present disclosure;

[0036] Figure 11 It is a schematic example of being instantiated as Figure 10 A diagram of the upper surface of electrode (b) used in a secondary battery;

[0037] Figure 12 This is a schematic diagram of the upper surface of an electrode for a secondary battery according to some embodiments of the present disclosure; and

[0038] Figure 13This is a graph showing the results of measuring the thickness of electrodes manufactured by a slot die coating machine according to some embodiments of the present disclosure. Detailed Implementation

[0039] Some embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The terms or words used in this specification and claims should not be construed as having a conventional or dictionary meaning, but should be interpreted as being consistent with the technical concept of this disclosure, based on the principle that the inventor is capable of being his / her own lexicographer to appropriately define the terms and concepts in order to best describe his / her disclosure.

[0040] The embodiments described in this specification and the configurations shown in the accompanying drawings are only some of the embodiments of this disclosure and do not represent all the technical spirit, aspects, and features of this disclosure. Therefore, it should be understood that various equivalents and modifications that can replace or modify the embodiments described herein may exist at the time of filing this application.

[0041] It will be understood that when an element or layer is described as being "on," "connected to," or "bonded to" another element or layer, it can be directly on, connected to, or combined with the other element or layer, or one or more intermediate elements or layers may be present. When an element or layer is described as being "directly" on, directly connected to, or directly combined with another element or layer, no intermediate elements or layers are present. For example, when a first element is described as being "bonded" or "connected" to a second element, the first element can be directly combined or connected to the second element, or the first element can be indirectly combined or connected to the second element via one or more intermediate elements.

[0042] In the accompanying drawings, the dimensions of various elements, layers, etc., may be enlarged for clarity of illustration. The same reference numerals indicate the same elements. As used herein, the term “and / or” includes any and all combinations of one or more associated listed items. Furthermore, the use of “may” in describing embodiments of this disclosure refers to “one or more embodiments of this disclosure.” Expressions such as “at least one of…” and “any one of…” preceding / following the list of elements modify the entire list of elements, but not individual elements in the list. When phrases such as “at least one of A, B, and C,” “at least one of A, B, or C,” “at least one selected from the group of A, B, and C,” or “at least one selected from A, B, and C” are used to specify a list of elements A, B, and C, the phrase may refer to any and all suitable combinations or subsets of A, B, and C, such as A, B, C, A and B, A and C, B and C, or A and B and C. As used herein, the term “use” may be considered synonymous with the term “utilize.” As used herein, the terms “roughly,” “approximately,” and similar terms are used as approximate terms rather than terms of degree and are intended to account for the inherent variations in measurements or calculations that would be apparent to a person skilled in the art.

[0043] It will be understood that while the terms first, second, third, etc., may be used to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. Therefore, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0044] For ease of description, this document uses spatial relative terms such as “below,” “under,” “down,” “above,” and “above” to describe the relationship between one element or feature and another element or feature as shown in the figures. It will be understood that spatial relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the figures. For example, in the case where the device in the figures is flipped, an element described as “below” or “under” other elements or features can be oriented as “above” or “above” other elements or features. Therefore, the term “below” can encompass both above and below orientations. The device can be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0045] The terminology used herein is for the purpose of describing embodiments of this disclosure and is not intended to be limiting of this disclosure. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. It will be further understood that when used in this specification, the terms “comprising” and / or “including” specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0046] Furthermore, any numerical ranges disclosed and / or enumerated herein are intended to include all subranges with the same numerical precision contained within the enumerated ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between the enumerated minimum value of 1.0 and the enumerated maximum value of 10.0 (and inclusive of both), i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as 2.4 to 7.6. Any maximum numerical limit enumerated herein is intended to include all lower numerical limits contained therein, and any minimum numerical limit enumerated in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to amend this specification, including the claims, to expressly enumerate any subranges contained within the scope expressly enumerated herein.

[0047] Referring to two compared elements, features, etc., as “identical” may mean that they are “substantially identical.” Therefore, the phrase “substantially identical” can include cases with a deviation considered low in the art, such as 5% or less. Furthermore, when a parameter is described as consistent within a given region, this may mean that it is consistent in terms of its mean.

[0048] Throughout this specification, unless otherwise stated, each element may be singular or plural.

[0049] Placing an optional element "above (or below)" or "on (or below)" another element may mean that the optional element can be configured to contact the upper (or lower) surface of the element, and other elements may also be located between the element and the optional element positioned on (or below) the element.

[0050] Furthermore, it will be understood that when a component is referred to as “connected,” “joined,” or “linked” to another component, the components can be directly “connected,” “joined,” or “linked” to each other, or another component can be “between” the components.

[0051] Throughout this specification, unless otherwise stated, when “A and / or B” is used, it means A, B, or A and B. In other words, “and / or” includes any or all of the listed items. Unless otherwise indicated, when “C~D” is used, it means greater than or equal to C and less than or equal to D.

[0052] The terminology used in this specification is intended to describe embodiments of this disclosure and is not intended to limit this disclosure.

[0053] Figure 1 This is a perspective view illustrating a slot die coating machine and a substrate according to some embodiments of the present disclosure. Figure 2 It is along Figure 1 The cross-sectional view taken from line AA'. Figure 3 This is an exploded perspective view illustrating a slot die coating machine according to some embodiments of the present disclosure. Figure 3 yes Figure 1 and Figure 2 An exploded perspective view of the slit mold coating machine 100 illustrated in the figure.

[0054] according to Figures 1 to 3 The slit mold coating machine 100 is illustrated as being horizontally arranged, but other configurations are also possible; for example, the slit mold coating machine 100 may be vertically arranged. In other embodiments, the substrate EP may be wound around the roller R and conveyed. Hereinafter, as an example, a slit mold coating machine 100 horizontally arranged on a substrate EP wound around the roller R and conveyed will be described.

[0055] refer to Figures 1 to 3 A slit-die coating machine 100 according to an embodiment of the present disclosure may include a first die block 110, a second die block 120, a third die block 130, a first spacer 142, and a second spacer 152. The second die block 120 may be on the first die block 110, and a first slit 140 may be formed (e.g., by combining the first die block 110 and the second die block 120) between the first die block 110 and the second die block 120. The third die block 130 may be on the second die block 120, and a second slit 150 may be formed (e.g., by combining the second die block 120 and the third die block 130) between the second die block 120 and the third die block 130. Figures 1 to 3 In this configuration, the first mold block 110 is positioned on the upper side and the third mold block 130 is positioned on the lower side. However, the third mold block 130 may be positioned on the upper side and the first mold block 110 may be positioned on the lower side.

[0056] refer to Figure 1 and Figure 2According to an embodiment, the slit-die coating machine 100 can be positioned close to one side of the wound and conveyed substrate EP. Therefore, substances discharged through the first discharge port 144 and the second discharge port 154 can be directly coated or applied to the substrate EP in a specific pattern. The substrate EP can be a roll-to-roll metal film or a roll-to-roll metal membrane. In some embodiments, the substrate EP can be an electrode substrate in an electrode assembly for a secondary battery. For example, copper (Cu) can be used as a negative electrode substrate, and aluminum (Al), nickel (Ni), and stainless steel can be used as positive electrode substrates. In an embodiment, the substrate EP can be continuously conveyed by the rotation of roller R, and the slit-die coating machine 100 can continuously apply a mixture and a barrier slurry to the conveyed substrate EP. The composition and characteristics of the mixture and barrier slurry applied by the slit-die coating machine 100 will be described later.

[0057] like Figure 1 and Figure 2 As illustrated, in one embodiment, the first mold block 110 and the second mold block 120 can be assembled at a predetermined interval between them. Therefore, a first slit 140 can be formed between the first mold block 110 and the second mold block 120. In other embodiments, the second mold block 120 and the third mold block 130 can be assembled at a predetermined interval between them. Therefore, a second slit 150 can be formed between the second mold block 120 and the third mold block 130. The first slit 140 and the second slit 150 can be empty chambers (e.g., empty spaces or cavities) with a constant width or a constant height, and can be unconnected to each other.

[0058] In some embodiments of this disclosure, in a cross-sectional view, both the first mold block 110 and the second mold block 120 may have a generally wedge-shaped portion whose thickness gradually decreases toward the first discharge port 144. In other embodiments, in a cross-sectional view, both the second mold block 120 and the third mold block 130 may have a generally wedge-shaped portion whose thickness gradually decreases toward the second discharge port 154. However, the mold blocks may have various shapes to facilitate the application of materials such as mixtures onto the substrate.

[0059] refer to Figure 1In an embodiment, the first slit 140 may extend horizontally between the first mold block 110 and the second mold block 120 (or be horizontally formed between the first mold block 110 and the second mold block 120). Furthermore, the second slit 150 may extend between the second mold block 120 and the third mold block 130 at an angle relative to the first slit 140 (or be obliquely formed between the second mold block 120 and the third mold block 130), so that it is closer to the first slit 140 the closer it is to the second discharge port 154 (e.g., the second slit 150 may be obliquely inclined at an acute angle relative to the first slit 140 so that the first discharge port 144 and the second discharge port 154 are adjacent to each other). However, the shapes of the first slit 140 and the second slit 150 may be changed; for example, if the two slits are close to each other on one side of the slit mold coating machine 100, each slit may be as follows: Figure 2 The cross-section has various degrees of inclination.

[0060] The first discharge port 144 may refer to the outlet defined by the combination of the first mold block 110, the second mold block 120, and the first separator 142. In other embodiments, the second discharge port 154 may refer to the outlet defined by the combination of the second mold block 120, the third mold block 130, and the second separator 152. In embodiments, the mixture may be discharged through the first discharge port 144 in direction MD1 (e.g., in a direction perpendicular to the surface of the substrate EP). The blocking slurry may be discharged through the second discharge port 154 in direction MD2 (e.g., in a direction at an angle relative to the surface of the substrate EP).

[0061] refer to Figure 1 The first discharge port 144 (e.g., the lateral length of the first discharge port 144) can be determined (e.g., can be set) for the width (or the width of the coated mixture layer formed by such a mixture) of the mixture discharged from and applied to the substrate EP through the first discharge port 144. The coated mixture layer can refer to the area in which the mixture is applied to the substrate. As described later, the lateral length of the first discharge port 144 can vary depending on the structure of the first spacer 142. In other embodiments, there can be at least two or more second discharge ports 154, and the spacing between the second discharge ports 154 can vary depending on the structure of the second spacer 152, as described later.

[0062] refer to Figure 2The second mold block 120 may have a first chamber 122 configured to contain a mixture, and a first slit 140 may be connected to the first chamber 122. The first chamber 122 may be formed in the second mold block 120. Accordingly, the mixture to be supplied contained in the first chamber 122 may move to the first slit 140, and the mixture may be discharged in a direction MD1 toward a first discharge port 144 connected to the first slit 140 by pressure applied from the first chamber 122. In other embodiments, the third mold block 130 may have a second chamber 132 configured to contain a blocking slurry, and a second slit 150 may be connected to the second chamber 132 containing the blocking slurry. The second chamber 132 may be formed in the third mold block 130. Accordingly, the blocking slurry to be supplied contained in the second chamber 132 may move to the second slit 150, and the blocking slurry may be discharged in a direction MD2 toward a second discharge port 154 connected to the second slit 150 by pressure applied from the second chamber 132.

[0063] The mixture can be continuously supplied to the first chamber 122 via a flow path. In this way, the mixture contained in the first chamber 122 can flow into the first slit 140. The barrier slurry can be continuously supplied to the second chamber 132 via a flow path, and the barrier slurry contained in the second chamber 132 can flow into the second slit 150. The barrier slurry will refer to... Figure 9 and Figure 10 As described later. The installation location and shape of the aforementioned flow paths connecting the first chamber 122 and the second chamber 132 can be changed.

[0064] In embodiments, the mixture may include electrode active materials, conductive materials, binders, etc. In the case of a positive electrode for a lithium secondary battery, the mixture as a positive electrode mixture (or a positive electrode mixture layer formed from the mixture) may include a positive electrode active material, and may further include a binder and / or a conductive material. In the case of a negative electrode, the mixture as a negative electrode mixture (or a negative electrode mixture layer formed from the mixture) may include a negative electrode active material, and may further include a binder and / or a conductive material. Any active material can be used as both the positive and negative electrode active materials, as long as it is commonly used in the field of secondary battery technology.

[0065] The binder functions to properly adhere electrode active material particles to each other and to properly adhere the electrode active material to a substrate (or current collector). For example, the binder may include polyvinyl alcohol, carboxymethyl cellulose, hydroxypropyl cellulose, diacetyl cellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, (meth)acrylated styrene-butadiene rubber, epoxy resin, (meth)acrylate resin, polyester resin, nylon, etc. However, this disclosure is not limited thereto.

[0066] Conductive materials can be used to make electrodes conductive. Any of a variety of electronically conductive materials can be selected and used as the conductive material in batteries configured using conductive materials, as long as the material does not cause a chemical change. For example, conductive materials can include carbon materials, metallic materials, conductive polymers, or mixtures thereof. Carbon materials can be natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fibers, carbon nanofibers, etc. Metallic materials can include copper, nickel, aluminum, silver, etc., and can be in the form of metal powder or metal fibers. In addition, conductive polymers can include polyphenylene derivatives, etc.

[0067] refer to Figure 1 and Figure 2 The first spacer 142 can be disposed in the first slit 140, and the second spacer 152 can be disposed in the second slit 150. For example, refer to Figure 3 The first spacer 142 may be disposed between the first mold block 110 and the second mold block 120 to form a first slit 140. In other embodiments, the second spacer 152 may be disposed between the second mold block 120 and the third mold block 130 to form a second slit 150.

[0068] refer to Figure 3 According to an embodiment, the first separator 142 may include an internal region I that connects the first slit 140 to the first discharge port 144 (e.g., to fluid communication between the first slit 140 and the first discharge port 144) and a shielding protrusion 146. The internal region I of the first separator 142 may be open at the first discharge port 144 and may be a chamber (e.g., a space or cavity) for containing the mixture. When the mixture is discharged through the first discharge port 144 and applied to a substrate, the internal region I of the first separator 142 may be configured to determine the width of the coated mixture layer. For example, the length of the open region in the internal region (I) on the first discharge port side may determine the width of the coated mixture layer.

[0069] like Figure 3As illustrated, in one embodiment, the shielding protrusion 146 of the first separator 142 can protrude from the inner region I toward the first discharge port 144. The specific structure of the shielding protrusion 146 will be referred to... Figures 4 to 6 This will be described later. The mixture contained in the inner region I may be biased (e.g., transferred or moved) to the edge of the first discharge port 144 due to the shielding protrusion 146 as the mixture flows toward the first discharge port 144. In other embodiments, the size of the inner region I may be relatively large at the edges due to the shielding protrusion 146. Therefore, when the mixture is applied to the substrate EP, the amount of mixture supplied to the edges of the applied mixture layer may be relatively large.

[0070] like Figure 3 As illustrated, the second separator 152 according to an embodiment may include notches 156_1 and 156_2 connected to a second discharge port 154. The second separator 152 may include a plurality of notches 156_1 and 156_2. The second discharge port 154 may include a plurality of second discharge ports formed at positions corresponding to the plurality of notches 156_1 and 156_2 (e.g., the number of second discharge ports 154 may be equal to the number of notches 156_1 and 156_2). The plurality of notches 156_1 and 156_2 may form a plurality of second slits. A blocking slurry may be contained in the plurality of notches 156_1 and 156_2 and discharged through the second discharge port 154 connected to the second slits. In this case, the notches 156_1 and 156_2 may guide the blocking slurry to overlap at least a portion of the edge portion of the coated mixture layer formed by the mixture discharged from the first discharge port 144 of the first separator 142. Here, the edge portions of the coated mixture layer refer to both ends of the coated mixture layer, and can be areas where the mixture tends to be applied in an inclined manner. For example, the notches 156_1 and 156_2 of the second separator 152 can be configured such that the blocking slurry is applied to overlap at least a portion of each of the edge portions at both ends of the coated mixture layer. The specific structure of the notches 156_1 and 156_2 will be referred to Figure 7 and Figure 8 To be described later.

[0071] As described above, due to the provision of the first separator 142 and the second separator 152, the second discharge port 154 can overlap with at least a portion of the two ends (e.g., opposite ends) or edge portion of the first discharge port 144. For example, as Figure 1 As illustrated, each of the second discharge ports 154 may be configured to overlap at least a portion of the end or edge portion of the first discharge port 144, such that a barrier film is formed at the edge portion of the coated mixture layer. The length of the overlap region between the first discharge port 144 and the second discharge port 154 may be in the range of about 0 mm to 0.5 mm.

[0072] refer to Figure 1 and Figure 2 In one embodiment, the first slit 140 may be disposed above the second slit 150. However, the second slit 150 may be disposed above the first slit 140. In other embodiments, the distance between the first discharge port 144 and the second discharge port 154 in the thickness direction may be zero (0). However, the first discharge port 144 and the second discharge port 154 may be formed to be spaced apart by a predetermined distance.

[0073] As described above, the mixture and the barrier slurry are simultaneously discharged by the slot die coater 100 and applied to the substrate EP. This allows the fabrication of a substrate with a barrier film disposed at the edge portion of the coated mixture layer. This mitigates any bulging or sagging at the edge portion of the coated mixture layer on the substrate. Therefore, the coated mixture layer can be formed on the substrate with a relatively uniform thickness.

[0074] Figure 4 This is a diagram schematically illustrating a first isolator according to some embodiments of the present disclosure. Figure 4 The first separator 400 shown in the example can be compared with the reference. Figures 1 to 3 The first isolator 142 described is largely the same.

[0075] refer to Figure 4 In an embodiment, the first spacer 400 may include a base portion 410, extension portions 420_1 and 420_2, and a shielding protrusion 430. For example... Figure 4 As illustrated, the base portion 410 may be located 144 meters from the first discharge port of the first separator 400. Figure 1 The furthest part. Multiple extensions 420_1 and 420_2 can extend from the same side of the substrate portion 410 toward the first discharge port 144 (e.g., multiple extensions 420_1 and 420_2 can extend from the substrate portion 410 toward the first discharge port 144). The arrangement of the multiple extensions 420_1 and 420_2 and the spacing between them can vary depending on the design of the width of the coated mixture layer to be manufactured.

[0076] In an embodiment, the shielding protrusion 430 may protrude from the base portion 410 in the direction MD1 toward the first discharge port 144, and may be disposed between a plurality of extensions 420_1 and 420_2 (e.g., the shielding protrusion 430 may protrude from the base portion 410 in the same direction as the plurality of extensions 420_1 and 420_2). For example, as Figure 4As illustrated, there may be two extensions 420_1 and 420_2, and the shielding protrusion 430 may be disposed between the first extension 420_1 and the second extension 420_2. In other embodiments, the shielding protrusion 430 may be formed at the junction of the first separator 400 and the first discharge port 144. Figure 1 ( ) Separated at the center of the interior. For example, the shielding protrusion 430 may be formed at the center of the interior of the base portion 410 or at the center between the first extension portion 420_1 and the second extension portion 420_2.

[0077] In other embodiments, the central portion of the shielding protrusion 430 may protrude close to the first discharge port 144. Figure 1 ). Inclined segments SS, symmetrical to each other relative to the centerline C of the shielding protrusion 430, may be formed on both sides (e.g., opposite sides) of the central portion. For example, see reference. Figure 4 The shielding protrusion 430 may include a central portion (e.g., centered between extensions 420_1 and 420_2, and having a flat edge extending parallel to the base portion 410 and facing the center of the first discharge port 144) and an inclined segment SS extending laterally from the central portion. For example, refer to Figure 4 The central portion and the two inclined sections SS on each side can define the outer contour of the shielding protrusion 340 facing the first discharge port 144.

[0078] The ends (e.g., ends or edges) of the extensions 420_1 and 420_2 according to the embodiments may have a form (e.g., structure) where the ends are bent in the direction toward the centerline C. For example, the ends of the extensions 420_1 and 420_2 may be bent at approximately 90 degrees in the direction toward the centerline C (e.g., the ends of the extensions 420_1 and 420_2 may be bent toward each other). The width W of the first discharge port 144 (e.g., measured between the ends of the extensions 420_1 and 420_2) may vary depending on the length by which the extensions 420_1 and 420_2 are bent and extended in the direction toward the centerline C. In some embodiments of this disclosure, the width of the first discharge port 144 may refer to the length between the outermost points facing each other, at which the portions (or ends) of the extensions 420_1 and 420_2 protrude the longest in the direction toward the centerline C.

[0079] In this embodiment, the width W of the first discharge port 144 formed by the ends of the extensions 420_1 and 420_2 can be approximately equal to the width of the coating mixture layer formed on the substrate. That is, the width of the coating mixture layer can be adjusted by changing the end structures of the extensions 420_1 and 420_2 (e.g., by adjusting the distance between the end structures of the extensions 420_2 and 420_1). Accordingly, the size of the coating mixture layer can be changed by altering the assembly of the first separator 400 of the slot die coater 100. Therefore, the degree of freedom for design changes can be increased.

[0080] Figure 5 This is a schematic diagram of a first spacer according to some embodiments of the present disclosure. Figure 4 Contrary to the first example of the isolation material, Figure 5 This is a schematic diagram illustrating how the first spacer 500 can form multiple coated mixture layers on the substrate by increasing the number of extended portions and shielding protrusions. Figure 4 The differences will be described in detail. Figure 5 The first separator 500 shown in the example can be compared with the reference. Figures 1 to 3 The first isolator 142 described is largely the same.

[0081] refer to Figure 5 According to an embodiment, the first spacer 500 may include a base portion 510, three extension portions 520_1 to 520_3, and two shielding protrusions 530_1 and 530_2. For example, the three extension portions 520_1 to 520_3 may extend from the same side of the base portion 510 at predetermined intervals, and the shielding protrusions 530_1 and 530_2 may be formed between two adjacent extension portions among the plurality of extension portions 520_1 to 520_2, respectively. For example, the first shielding protrusion 530_1 may be formed substantially centrally between the first extension portion 520_1 and the second extension portion 520_2, and the second shielding protrusion 530_2 may be formed substantially centrally between the second extension portion 520_2 and the third extension portion 520_3.

[0082] According to an embodiment, the ends of two extensions 520_1 and 520_3, which are located at both ends of the first spacer 500, among the plurality of extensions 520_1 to 520_3, can be bent toward the center of the first spacer 500. For example, each of the ends of the first extension 520_1 and the third extension 520_3 can be bent toward the center of the first spacer 500. In this case, the second extension 520_2 can have an unbent end. The width W1 between the bent end of the first extension 520_1 and the end of the second extension 520_2 can determine the width of the first coated mixture layer. In other embodiments, the width W2 between the bent end of the third extension 520_3 and the end of the second extension 520_2 can determine the width of the second coated mixture layer.

[0083] The aforementioned first separator 500 may have a structure in which a notch is configured to correspond to the end of the extended portion. In this way, a substrate having multiple coated mixture layers and multiple barrier films can be manufactured by a slit mold coating machine capable of performing multi-row coating. For example, to improve the productivity of a facility for manufacturing electrodes for secondary batteries, an electrode comprising eight coated mixture layers can be manufactured using a slit mold coating machine comprising a first separator having nine extended portions and eight shielding protrusions formed on a substrate portion.

[0084] Figure 6 This is a schematic diagram of a first isolator according to some embodiments of the present disclosure. Figure 6 It is used for example Figure 5 A diagram illustrating another embodiment of the first separator. (Compared to...) Figure 4 and Figure 5 The differences will be described in detail. Figure 6 The first isolation element 600 shown in the example can be compared with the reference. Figures 1 to 3 The first isolator 142 described is largely the same.

[0085] refer to Figure 6 In an embodiment, at least a portion of the end of the extension 620_2, which is located between the two extensions 620_1 and 620_3 at both ends of the first spacer 600, of the plurality of extensions 620_1 to 620_3, may be bent toward at least one of the two extensions 620_1 and 620_3 located at both ends. In an embodiment, referring to... Figure 6The first shielding protrusion 630_1 may be generally formed in the center between the first extension 620_1 and the second extension 620_2. Furthermore, the second shielding protrusion 630_2 may be generally formed in the center between the second extension 620_2 and the third extension 620_3. For example, one end of the second extension 620_2 may be bent toward the first extension 620_1, and the other end of the second extension 620_2 may be bent toward the third extension 620_3 (e.g., the end of the second extension 620_2 may have a T-shape).

[0086] For example, the width W3 between the bent end of the first extension 620_1 and the bent end of the second extension 620_2 toward the first extension 620_1 can determine the width of the first coated mixture layer. In other embodiments, the width W4 between the bent end of the third extension 620_3 and the bent end of the second extension 620_2 toward the third extension 620_3 can determine the width of the second coated mixture layer.

[0087] As referenced above Figure 5 and Figure 6 The first isolator 600 (as described) Figure 3 The location where the mixture in the internal region I is discharged can be varied depending on the various end structures of the extensions 620_1 to 620_3.

[0088] When the shielding protrusion has a shape that protrudes towards the first discharge port MD1, the following can be used: Figures 4 to 6 Various shapes are illustrated in the diagram. Here, they are contained within the internal region I ( Figure 3 The flow of the mixture in the shielding protrusions can vary depending on their size.

[0089] Figure 7 and Figure 8 This is a schematic diagram of a second spacer according to some embodiments of the present disclosure. (The diagram is shown in...) Figure 7 or Figure 8 The second separator 700 or 800 shown in the example can be compared with the above reference. Figures 1 to 3 The second isolator 152 described is largely the same.

[0090] refer to Figure 7 and Figure 8 The shape and size of the second spacer 700 or 800 according to the embodiment can be substantially the same as the shape and size of the second spacer facing the second mold block 120 and the third mold block 130 in the slot die coating machine 100. For example, the second spacer 700 or 800 can have a generally rectangular plate-like member.

[0091] In other embodiments, the second barrier may include an enclosure facing the second discharge port 154. Figure 1 Multiple open notches. The multiple notches can be configured to correspond to the edge portions of the coating mixture layer (e.g., the edge portions of the mixture applied to the substrate EP through the first discharge port 144). The multiple notches can extend in a direction opposite to the second discharge port 154 (e.g., oriented away from the second discharge port 154) (negative MD2 direction).

[0092] For example, refer to Figure 7 According to an embodiment, the second barrier 700 may include a first recess 710_1 and a second recess 710_2 opening toward the second discharge port MD2. The barrier slurry contained in each of the first recess 710_1 and the second recess 710_2 may be discharged toward the second discharge port MD2. A barrier film formed by the barrier slurry may be disposed at the edge portion of the coated mixture layer.

[0093] As another example, see Figure 8 According to an embodiment, the second barrier 800 may include a first recess 810_1 to a fifth recess 810_5 opening toward the second discharge port MD2. The barrier slurry contained in each of the first recess 810_1 to the fifth recess 810_5 may be discharged toward the second discharge port MD2. A barrier film formed by the barrier slurry may be disposed at each edge portion of the coated mixture layer. Reference will be made later. Figure 12 The description includes Figure 8 The example shown is a specific structure of an electrode for a secondary battery manufactured by a slit mold coating machine of the second separator 800.

[0094] Figure 9 This is a diagram used to explain the effects obtained by a slot die coating machine according to some embodiments of the present disclosure. Figure 9 This is a schematic diagram illustrating a cross-section of an electrode for a secondary battery according to some embodiments of the present disclosure. In the following, the electrode for the secondary battery can be manufactured using the slit mold coating machine 100 described above.

[0095] refer to Figure 9 The electrode for a secondary battery according to an embodiment may include a substrate EP, a coated mixture layer 910, and barrier films 920_1 and 920_2. The substrate EP may be connected to a reference... Figures 1 to 3 The substrates described are generally the same. The coating mixture layer 910 can be formed by applying the mixture discharged through the first slit of the slit die coater 100 onto the substrate EP. The width of the coating mixture layer 910 can be approximately equal to the width of the first discharge port connected to the first slit or the length between the facing ends of the two extensions disposed at both ends of the first separator.

[0096] The edge portion Ed of the mixture can refer to the portions of the mixture applied to the substrate EP at both ends, where the surface of the mixture may have a shape inclined at a predetermined angle. For example, the thickness or loading of the edge portion Ed of the mixture may be less than the thickness or loading of the central portion of the mixture. The central portion refers to the area excluding the edge portion Ed. Deviations in the thickness or loading of the mixture may lead to degradation of the electrode quality. In other embodiments, the overall loading of the mixture may be less than the designed loading of the mixture for the electrode of a secondary battery. For example, the greater the inclination relative to the thickness direction of the edge portion Ed of the mixture, the less likely the loading of the mixture may be than the design value.

[0097] Specifically, when the loading of the coated negative electrode mixture is less than the design value, the N / P ratio can be less than 1. Therefore, during the charging and discharging of the lithium secondary battery, lithium ions from the positive electrode may not be fully contained in the negative electrode mixture. Consequently, lithium ions may deposit (plate) as lithium metal. The N / P ratio can be defined as the value obtained by dividing the capacity (mAh / g) of the negative electrode active material by the capacitance of the positive electrode active material. As lithium deposition continues according to the charging and discharging of the lithium secondary battery, lithium dendrites may grow on the negative electrode and come into contact with the positive electrode, potentially leading to short circuits and fires.

[0098] However, when using a slot die coater according to some embodiments of this disclosure to coat the mixture and the electrode blocking the slurry, the tilted shape of the edge portion of the mixture (Ed) can be reduced. Therefore, the quality of the aforementioned electrode is less likely to deteriorate, and / or short circuits and fires in the secondary battery are less likely to occur.

[0099] refer to Figure 9 In part (A), according to an embodiment, the amount of mixture loaded on the edge portion Ed may increase due to the shielding protrusions of the first separator. Therefore, a convexity of a predetermined thickness may occur. However, without providing a barrier film, the inclined shape of the edge portion Ed may still be maintained. Therefore, the aforementioned deficiency in the amount of mixture loaded may not be resolved.

[0100] In comparison, reference Figure 9In part (B), where the barrier films 920_1 and 920_2 are formed to overlap at least a portion of the edge portion Ed, the phenomenon of the mixture bulging upwards at the edge portion Ed is less likely to occur, and the tilt of the shape at both ends can be reduced. For example, after the barrier slurry and the mixture are applied to the substrate EP, the mixture can flow towards the barrier film while the barrier films 920_1 and 920_2 are formed due to the surface tension between the barrier slurry and the mixture. For example, the mixture in the bulging portion of the edge portion Ed can flow substantially downwards. At the same time, the mixture occupying the bulging portion of the coated mixture layer 910 can flow substantially towards the barrier film 920_1 or 920_2 due to the surface tension of the barrier films 920_1 and 920_2. Accordingly, the thickness deviation between the central portion of the mixture and the edge portion Ed can be reduced. Thus, the quality of the electrode can be improved, and the risk of short circuit or fire in the secondary battery due to insufficient loading of the negative electrode mixture can be reduced.

[0101] According to an embodiment, barrier films 920_1 and 920_2 can be formed at both ends of the coated mixture layer 910 by applying a barrier slurry discharged through a second slit of a slit die coater onto a substrate EP. The barrier slurry can be a substance that applies surface tension to the mixture, can be fixed to the substrate EP, and can guide the flow rate control of the mixture. For example, the barrier slurry can include a water-soluble polymer. In some embodiments, the water-soluble polymer can include carboxymethyl cellulose salts.

[0102] For example, barrier slurries may include sodium carboxymethyl cellulose (SCMC), potassium carboxymethyl cellulose (KCMC), calcium carboxymethyl cellulose (CaCMC), ammonium carboxymethyl cellulose, or combinations thereof.

[0103] In embodiments, the viscosity of the blocking slurry can be equal to or greater than the viscosity of the mixture. For example, the viscosity of the blocking slurry can be in the range of about 0% to 20% greater than the viscosity of the mixture. For example, the blocking slurry and the mixture can mix with each other due to surface tension, thereby improving the tilt shape of the edge portion Ed of the mixture.

[0104] Figure 10 This is a schematic diagram illustrating the cross-section of an electrode for a secondary battery according to some embodiments of the present disclosure. Figure 9 The differences will be highlighted. In the following text, the electrodes for secondary batteries can be manufactured using the aforementioned slit mold coating machine 100.

[0105] refer to Figure 10In the electrode for a secondary battery according to an embodiment, an overlapping section OL may be formed, wherein a region of each of the barrier films 1020_1 to 1020_4 overlaps with a region of the coated mixture layer 1010 in the overlapping section OL. The overlapping section OL may be a section in which the barrier slurry and mixture are mixed. In other embodiments, the overlapping section OL may be a section in which moisture is removed from the composite of the barrier slurry and mixture. The maximum width of the overlapping section OL may be in the range of about 20% to 50% of the maximum width of the barrier films (any one of 1020_1 to 1020_4).

[0106] In an embodiment, the maximum thickness of the barrier films 1020_1 to 1020_4 on the substrate EP can be equal to or less than the maximum thickness of the coated mixture layer 1010. (See reference...) Figure 10 In electrode (a) after coating using a slot die coater and before drying, the maximum thickness of barrier films 1020_1 and 1020_2 can be equal to or less than the maximum thickness of the coated mixture layer 1010. In electrode (b) after coating using a slot die coater and after drying, the maximum thickness of barrier films 1020_3 and 1020_4 can be less than the maximum thickness of the coated mixture layer 1010. Barrier films 1020_3 and 1020_4 can be formed by removing moisture from the barrier paste (or barrier films 1020_1 and 1020_2) coated onto the substrate EP through an electrode drying process.

[0107] In an embodiment, the thickness of the coated mixture layer 1010 in electrode (a) after coating with a slit mold coater and before drying can be greater than the thickness of the coated mixture layer 1010 in electrode (b) after coating with a slit mold coater and before drying.

[0108] For example, in electrode (a) after coating using a slit mold coater and before drying, the thickness of the barrier films 1020_1 and 1020_2 can be in the range of about 0% to 20% of the thickness of the coated mixture layer 1010. In electrode (b) after coating using a slit mold coater and after drying, the thickness of the barrier films 1020_3 and 1020_4 can be in the range of about 0% to 1.5% of the thickness of the coated mixture layer 1010.

[0109] refer to Figure 9 and Figure 10 The shape of the barrier film is illustrated as a specific shape. However, this shape can be changed, as long as the barrier film can occupy a chamber such that at least a portion of the barrier film overlaps with the edge portion Ed of the coated mixture layer.

[0110] Figure 11 It is a schematic example of being instantiated as Figure 10 A diagram of the upper surface of electrode (b) for a secondary battery. In the following text, the electrode for the secondary battery can be manufactured using the slit mold coating machine 100 described above. Figure 11 This is a diagram used to explain the location of the barrier membrane that removes moisture from the barrier slurry during the drying process.

[0111] refer to Figure 11 In an embodiment, the electrode for the secondary battery may include a coated mixture layer 1010, barrier films 1020_3 and 1020_4, and an uncoated section 1110. Each uncoated section 1110 may refer to an area on the substrate where no material is coated. For example, the uncoated section 1110 may refer to an area other than the areas where the barrier films 1020_3 and 1020_4 and / or the areas where the coated mixture layer 1010 is disposed on the substrate. This area may be processed into an electrode terminal of the secondary battery, or may be electrically connected to a separate electrode terminal. Here, the electrode terminal may serve as a current collector connected to a terminal of the secondary battery.

[0112] In an embodiment, the coated mixture layer 1010 may have overlapping sections OL. The coated mixture layer 1010 can be applied from the first discharge port of a slot die coater (e.g., Figure 1 The mixture is formed by discharging the mixture from the 144). Each overlapping segment OL can be a segment in which the area of ​​the coating mixture layer 1010 overlaps with the areas of the barrier films 1020_3 and 1020_4. The barrier films 1020_3 and 1020_4 can be discharged from the second discharge port of the slit die coating machine (e.g., Figure 1 (154) The blocking slurry discharged is applied to both ends of the mixture to form it.

[0113] In an embodiment, the slot die coating machine can be configured as follows. A first separator (e.g., Figure 4 The 400) may include two extensions (e.g., Figure 4 420_1, 420_2), the second separator (e.g., Figure 7 The 700) may include two notches (e.g., Figure 7 (710_1, 710_2), and these two notches are configured such that the ends of the two extensions correspond to each other. Using a slot die coating machine, such as... Figure 11 As illustrated, a barrier film 1020 can be manufactured and disposed at electrodes at both ends of the coated mixture layer 1010.

[0114] In an embodiment, the width W' of the coated mixture layer can be determined by the width between the ends of the extension portion of the first separator (e.g., Figure 4The width W' of the coated mixture layer can be determined by the first discharge port (e.g., W'). In other embodiments, the width W' of the coated mixture layer can be determined by the first discharge port (e.g., W'). Figure 1 The width of 144 in the middle is determined.

[0115] Figure 12 This is a schematic diagram of the upper surface of an electrode for a secondary battery according to some embodiments of the present disclosure. Figure 12 Show Figure 11 Another embodiment of an electrode for a secondary battery is illustrated in the figure.

[0116] refer to Figure 12 In an embodiment, the slot die coating machine can be configured as follows: The first spacer includes five extensions, and the second spacer (e.g., Figure 8 The 800) includes five notches (e.g., Figure 8 (810_1 to 810_5), and the five notches are respectively set to correspond to the ends of the five extensions. Using a slot die coating machine, such as... Figure 12 As illustrated, a multi-row coated electrode can be manufactured in which four coated mixture layers (1220_1 to 1220_4) and five barrier films (1230_1 to 1230_5) are arranged.

[0117] In one embodiment, the widths W_1 to W_4 of the coated mixture layer can be determined by the width between the terminals of adjacent extensions of the five extensions of the first separator. In other embodiments, the widths W_1 to W_4 of the coated mixture layer can be determined by the widths of the five first discharge ports.

[0118] Figure 13 This is a graph illustrating the results of measuring the thickness of an electrode manufactured by a slot die coating machine. Figure 13 This is a graph illustrating the results of measuring the electrode thickness of a secondary battery based on its position within the coated mixture layer. The X-axis of the graph represents the position (mm) within the coated mixture layer, and the Y-axis represents the electrode thickness (µm). Here, the position within the coated mixture represents the length from one end of the edge portion of the coated mixture layer, and the electrode thickness refers to the total thickness of the substrate and the coated mixture layer. Furthermore, the position within the coated mixture layer only illustrates a portion of the central portion of the coated mixture layer.

[0119] refer to Figure 13 , Figure 13The thickness evaluation result (1) of the electrode for a secondary battery according to the first example shows the result of sampling and measuring the thickness (µm) of one of the eight rows of coated electrodes in which a barrier film is used in the coated mixture layer formed by a first separator including shielding protrusions. The thickness evaluation result (2) of the electrode for a secondary battery according to the second example differs from the thickness evaluation result (1) of the first example in that the thickness evaluation result (2) shows the result of sampling and measuring the thickness (µm) of one of the eight rows of coated electrodes in which a barrier film is not used in the coated mixture layer formed by a first separator including shielding protrusions.

[0120] Referring to the thickness evaluation results (2) of the electrode for a secondary battery according to the second example, the following fact was found: The electrode thickness within the coated mixture layer in the range of approximately 0 mm to 5 mm (corresponding to the edge portion of the coated mixture layer) is greater than the electrode thickness within the range of approximately 5 mm to 15 mm (corresponding to the central portion of the coated mixture layer). Conversely, referring to the thickness evaluation results (1) of the electrode for a secondary battery according to the first example, the following fact was found: The electrode thickness within the coated mixture layer in the range of approximately 0 mm to 5 mm (corresponding to the edge portion of the coated mixture layer) is less than the electrode thickness within the range of approximately 5 mm to 15 mm (corresponding to the central portion of the coated mixture layer). In this way, it was found that by employing a barrier film, the upward bulge at the edge portion of the coated mixture layer was improved.

[0121] According to some embodiments of this disclosure, a substrate with a barrier film disposed at the edge portion of the coated mixture layer can be manufactured by simultaneously discharging the mixture and barrier slurry through a slot die coater and applying the mixture and barrier slurry onto the substrate. This can relatively reduce bulging or sagging at the edge portion of the coated mixture layer on the substrate. Therefore, the coated mixture layer can be formed on the substrate with a relatively uniform thickness.

[0122] According to some embodiments of this disclosure, when using a slot die coater to apply the mixture and the electrode that blocks the slurry, the tilt of the edge portion of the mixture in the thickness direction can be reduced. Therefore, the degradation of electrode quality and / or the possibility of short circuits or fires in the secondary battery can be reduced.

[0123] According to some embodiments of this disclosure, the size of the coating mixture layer and / or the size of the barrier film applied to the substrate can be changed by altering and assembling the first or second spacer of the slot die coater. Therefore, the degree of freedom in designing the slot die coater can be increased.

[0124] However, the aspects and features of this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the above detailed description other aspects and features not mentioned.

[0125] While this disclosure has been described above with reference to embodiments thereof, it is not limited thereto. Those skilled in the art can make various modifications and variations thereto within the spirit and equivalent scope of the claims.

[0126] Example embodiments have been disclosed herein. While specific terminology has been used, it is used and interpreted in a general and descriptive sense only and not for limiting purposes. In some cases, as will be apparent to those skilled in the art at the time of filing this application, unless otherwise specifically stated, features, characteristics, and / or elements described in connection with particular embodiments may be used alone or in combination with features, characteristics, and / or elements described in connection with other embodiments. Therefore, those skilled in the art will understand that various changes in form and detail may be made without departing from the spirit and scope set forth in the claims of this invention.

Claims

1. A slot die coating machine, comprising: First mold block; A second mold block on the first mold block, the second mold block having a first chamber configured to contain the mixture; The first slit between the first mold block and the second mold block; A third mold block on the second mold block, the third mold block having a second chamber configured to contain blocking slurry; The second slit between the third mold block and the second mold block; The first spacer in the first slit, the first spacer comprising: The internal region connects the first slit to a first discharge port, the first discharge port being used to define the width of the mixture discharged from and applied to the substrate through the first discharge port. A shielding protrusion extends from the internal region toward the first discharge port; as well as The second separator in the second slit includes a notch connecting the second slit to the second discharge port, and the second discharge port overlaps with at least a portion of the edge portion of the first discharge port.

2. The slit mold coating machine according to claim 1, wherein the shielding protrusion is located in the center of the interior of the first separator, and the shielding protrusion is spaced apart from the first discharge port.

3. The slit mold coating machine according to claim 1, wherein the shielding protrusion includes a central portion protruding toward the first discharge port and inclined sections symmetrical to each other with respect to the centerline of the shielding protrusion, the inclined sections being on the opposite side of the central portion.

4. The slit mold coating machine according to claim 1, wherein: The first separator further includes a base portion and a plurality of extension portions extending from one side of the base portion toward the first discharge port, and The shielding protrusions extend from the base portion toward the first discharge port, and the shielding protrusions are located between the plurality of extension portions.

5. The slit mold coating machine according to claim 4, wherein the ends of two of the plurality of extensions, respectively at opposite ends of the first separator, are bent toward the center of the first separator.

6. The slot die coating machine according to claim 5, wherein at least a portion of the end of one of the plurality of extensions located between the two extensions at opposite ends of the first separator is bent toward at least one of the two extensions.

7. The slit mold coating machine according to claim 4, wherein the shielding protrusion is between two adjacent extensions of the plurality of extensions.

8. The slit mold coating machine according to any one of claims 1 to 7, wherein the second discharge port overlaps with at least a portion of the opposite end of each of the first discharge ports.

9. The slit mold coating machine according to any one of claims 1 to 7, wherein the first slit is above the second slit.

10. The slit mold coating machine according to claim 9, wherein: The first slit extends horizontally between the first mold block and the second mold block, and The second slit extends between the second mold block and the third mold block at an angle relative to the first slit, so that it is closer to the first slit the closer it is to the second discharge port.

11. The slit mold coating machine according to any one of claims 1 to 7, wherein the distance between the first discharge port and the second discharge port in the thickness direction is 0.

12. The slit mold coating machine according to any one of claims 1 to 7, wherein the blocking slurry comprises a water-soluble polymer.

13. The slot die coating machine according to claim 12, wherein the water-soluble polymer comprises carboxymethyl cellulose salt.

14. The slot die coating machine according to any one of claims 1 to 7, wherein the notch of the second separator comprises a plurality of notches opening toward the second discharge port, the plurality of notches corresponding to the edge portion of the mixture applied to the substrate through the first discharge port.

15. The slot die coating machine of claim 14, wherein the plurality of notches extend in a direction away from the orientation of the second discharge port.

16. An electrode for a secondary battery, comprising: substrate; A coating mixture layer is applied to the substrate, the coating mixture layer comprising the mixture discharged through the first slit of the slit die coating machine as described in any one of claims 1 to 15; and A barrier film on the substrate, the barrier film being located at the opposite end of the coated mixture layer, the barrier film comprising the barrier slurry discharged through the second slit of the slit die coater.

17. The electrode for a secondary battery according to claim 16, wherein the maximum thickness of the barrier film on the substrate is less than the maximum thickness of the coated mixture layer.

18. The electrode for a secondary battery according to claim 16, wherein the barrier film is formed by removing moisture from the barrier slurry.

19. The electrode for a secondary battery according to claim 16, wherein the viscosity of the blocking slurry is equal to or greater than the viscosity of the mixture.

20. The electrode for a secondary battery according to claim 16, wherein the mixture comprises an electrode active material, a conductive material, and a binder.

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