Coating equipment

Abstract

The present invention relates to a coating apparatus comprising: a first block having a receiving portion which is opened by an open region having a predetermined horizontal length and a predetermined vertical length and which is capable of receiving a coating liquid; a second block spaced apart from the first block by a predetermined distance and disposed opposite the open area of the receiving portion; a slot defining a space between the first block and the second block and provided to be capable of receiving the coating liquid from the receiving portion and discharging the coating liquid to the outside; and a plate gasket provided in the slot to vary the flow of the coating liquid conveyed from the receiving portion to the slot by closing a portion of the open area of the receiving portion, in which the plate gasket may include: a width limiting portion that limits the width of the coating liquid conveyed from the receiving portion to the slot; the sealing part is used for sealing a partial area of the open area in the horizontal direction from at least one of the side ends of the receiving part in the horizontal direction; and a height limiting portion that closes a partial region of the open region of the receiving portion in the vertical direction.

Description

Technical Field

[0001] This disclosure relates to a coating apparatus, and more specifically, to a coating apparatus including a plate gasket. This application is based on and claims priority to Korean Patent Application No. 10-2023-0138974, filed on October 17, 2023, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Background Technology

[0002] As the demand for mobile devices increases with technological advancements, the demand for secondary batteries as energy sources is rapidly growing, and these secondary batteries essentially consist of electrode assemblies that serve as power generation elements. Electrode assemblies are constructed by stacking a positive electrode, a separator, and a negative electrode at least once, and the positive and negative electrodes are manufactured by coating positive and negative active material slurries, respectively, onto current collectors made of aluminum and copper foil and then drying them. These secondary batteries typically use layered crystalline lithium cobalt oxide (LiCoO2), layered crystalline lithium manganese oxide (such as LiMnO2), or spinel crystalline LiMn2O4 and lithium nickel oxide (LiNiO2) as positive electrode active materials. Furthermore, carbon-based materials are commonly used as negative electrode active materials, and, in response to the increasing demand for high-energy lithium secondary batteries, they are currently considered to be used in combination with silicon-based or silicon oxide-based materials, which have an effective capacity 10 times higher than carbon-based materials. To obtain uniform charge / discharge characteristics of the secondary battery, the positive and negative active material slurries must be uniformly coated onto the current collector.

[0003] To improve the accuracy of coating equipment, the coating liquid must be applied thinly and evenly to the substrate.

[0004] However, existing coating equipment cannot control the discharge rate of the coating liquid, or even when controlling the coating equipment, the coating liquid applied to the substrate is not uniform in the width direction of the entire discharge port.

[0005] Therefore, there is a need for a coating device that can improve coating uniformity compared to conventional coating devices. Summary of the Invention

[0006] Technical issues

[0007] This disclosure aims to address the problems of the prior art, and therefore the object of this disclosure is to provide a coating apparatus including a plate pad configured to improve the coating uniformity on a coating body.

[0008] This disclosure also provides a coating apparatus including a plate pad configured to maximize the area over which the coating thickness of the coated body reaches a target thickness.

[0009] However, the technical problems to be solved by this disclosure are not limited to the above-mentioned problems, and those skilled in the art will clearly understand from the following description of the invention that other problems not mentioned above will be addressed.

[0010] Technical solution

[0011] According to one aspect of this disclosure, a coating apparatus is provided, the coating apparatus comprising: a first block having a receiving portion openable through an opening having a predetermined horizontal length and a predetermined vertical length, the receiving portion being configured to receive a coating liquid; a second block spaced apart from the first block by a predetermined distance and disposed opposite to the opening of the receiving portion; a slot defined as a space between the first block and the second block and configured to receive the coating liquid from the receiving portion and discharge the coating liquid to the outside; and a plate gasket disposed in the slot and configured to close a portion of the opening of the receiving portion, thereby altering the flow of the coating liquid from the receiving portion to the slot, wherein the plate gasket includes a width limiting portion and a height limiting portion, the width limiting portion being configured to close a portion of the opening of the receiving portion in the horizontal direction from at least one of its horizontal ends, and the height limiting portion being configured to close a portion of the opening of the receiving portion in the vertical direction.

[0012] Furthermore, the plate gasket can be configured to be replaceable.

[0013] Furthermore, the width limiting portion can be located at each of the horizontal ends of the receiving portion, and the height limiting portion can be located between the two width limiting portions.

[0014] Furthermore, the height limiting portion may include a straight portion whose edge shape changes linearly along the horizontal direction and a curved portion whose edge shape changes along the horizontal direction with a curve having a predetermined radius of curvature.

[0015] Furthermore, the vertical length of the straight portion can become the maximum at the boundary between the straight portion and the curved portion, and gradually decreases as it moves further away from the curved portion in the horizontal direction.

[0016] Furthermore, the straight section can be positioned at each of the horizontal ends of the height limiting section.

[0017] Furthermore, the curved portion can be positioned between two straight portions.

[0018] Furthermore, the height-limiting portion may have a shape that is approximately symmetrical in the horizontal direction with respect to the horizontal centerline of the curved portion.

[0019] Furthermore, the edge of the width limiting portion can be configured to be approximately parallel to the vertical direction, and the slope of the straight portion can have an angle of approximately 60 to 85 degrees relative to the edge of the width limiting portion.

[0020] Furthermore, the vertical length of the curved portion can become the maximum value at the horizontal center of the curved portion and the minimum value at the boundary with the two straight portions.

[0021] Furthermore, the vertical length of the curved portion can gradually decrease from the horizontal center of the curved portion toward the two straight portions.

[0022] Furthermore, the vertical length of the opening of the receiving portion at the horizontal center of the curved portion can be approximately 50% to 55% of its vertical length at the boundary between the curved portion and the straight portion.

[0023] Furthermore, the horizontal length of the curved portion can be approximately 4.5 to 5.5 times the horizontal length of the straight portion.

[0024] Furthermore, the width of the slot and the thickness of the plate gasket can be approximately the same.

[0025] Furthermore, the coating apparatus according to this disclosure may also include a roller configured to transport a coating body by rotation of the roller body and the roller being positioned at a predetermined distance from the slot, and the slot being configured to discharge the coating liquid onto the coating body as the roller body rotates, thereby coating the coating body.

[0026] Furthermore, the coating body can be an electrode to be used in a battery, and the coating liquid can be an electrode slurry for coating the electrode.

[0027] Beneficial effects

[0028] According to embodiments of this disclosure, the uniformity of coating on the coated body can be improved.

[0029] According to another aspect of this disclosure, compared with the prior art, the area where the coating thickness of the coated body reaches the target thickness can be maximized. Attached Figure Description

[0030] Figure 1 This is a conceptual diagram illustrating a coating apparatus according to an embodiment of the present disclosure.

[0031] Figure 2This is an exploded perspective view showing a coating unit of a coating apparatus according to an embodiment of the present disclosure.

[0032] Figure 3 This is a conceptual diagram showing a plate pad of a coating apparatus according to an embodiment of the present disclosure.

[0033] Figure 4 This is a conceptual diagram showing a plate pad for a conventional coating device.

[0034] Figure 5 This is a cross-sectional view showing the coating of an object according to conventional coating equipment.

[0035] Figure 6 This is a cross-sectional view of a coated body coated by a coating apparatus according to an embodiment of the present disclosure.

[0036] Figure 7 This is a diagram showing experimental coating results obtained from a coating apparatus according to an embodiment of the present disclosure.

[0037] Figure 8 This is a diagram showing experimental coating results obtained from a coating apparatus according to an embodiment of the present disclosure.

[0038] Figure 9 This is a graph showing a comparison of the coating cross-sections between conventional coating equipment and the improved coating equipment of this disclosure. Detailed Implementation

[0039] The preferred embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The drawings illustrate preferred embodiments of the present disclosure and, together with the detailed description of the invention, serve to provide a further understanding of the technical concept of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings. The same reference numerals denote the same elements. Furthermore, for the purpose of clarifying the present disclosure, the thickness, proportions, and dimensions of the various elements shown in the drawings may be exaggerated.

[0040] It should be understood that the terms used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but rather are interpreted based on the principle that inventors are allowed to appropriately define terms for best interpretation, and on the meanings and concepts corresponding to the technical aspects of this disclosure.

[0041] At the same time, although terms indicating directions such as up, down, left, right, front, and back are used in this specification, it will be apparent to those skilled in the art that these terms are for ease of explanation only and may vary depending on the position of the target object or the observer's position.

[0042] Therefore, the constructions presented in the embodiments and drawings of this specification only indicate the most preferred embodiments of this disclosure and do not represent all the technical ideas of this disclosure. It should be understood that various equivalents and modifications can be made to them when this application is filed.

[0043] In the following text, reference will be made to Figures 1 to 8 This invention describes a coating apparatus including a plate gasket according to embodiments of the present disclosure.

[0044] Figure 1 This is a conceptual diagram illustrating a coating apparatus according to an embodiment of the present disclosure. Figure 2 This is an exploded perspective view showing a coating unit of a coating apparatus according to an embodiment of the present disclosure.

[0045] The coating equipment 1 may include a coating unit 100 and a roller 200. The coating equipment 1 may also be called by other names, such as a slot die coating machine, etc.

[0046] The coating apparatus 1 can apply the coating liquid L to the coating body B. For example, the coating body B can be an electrode to be used in a secondary battery, and the coating liquid L can be a slurry to be applied to the electrode.

[0047] The slurry can be either a positive electrode active material or a negative electrode active material. The electrode can be configured such that the positive electrode, the separator, and the negative electrode are laminated at least once. The positive and negative electrodes can be manufactured by coating the positive electrode active material or the negative electrode active material onto a current collector made of aluminum foil and copper foil, respectively, and then drying them.

[0048] The coating apparatus 1 can be used to coat positive electrode active materials and / or negative electrode active materials onto electrodes to be used in secondary batteries.

[0049] The coating unit 100 may include a first block 110, a second block 120, a slot 130, a plate gasket 140, and an injection hose 150. The coating unit 100, including the above-mentioned components, can apply coating liquid L to the coating body B conveyed by the roller 200.

[0050] The first block 110 may have a receiving portion 111, which opens in one direction through an opening P having a predetermined horizontal length H and a predetermined vertical length V. (Refer to...) Figure 1 and Figure 2 The opening P of the receiving portion 111 can face the +X axis direction. The receiving portion 111 can receive the coating liquid L in its internal space.

[0051] The first piece 110 may have an inlet 112 for injecting the coating liquid L into the receiving portion 111. The inlet 112 is a channel communicating with a portion of the receiving portion 111, and a hose 150 may be inserted therein. The hose 150 may be inserted into the inlet 112 to inject the coating liquid L into the interior space of the receiving portion 111.

[0052] The second block 120 can be spaced apart from the first block 110 by a predetermined distance and positioned relative to the opening P of the receiving portion 111. The space between the first block 110 and the second block 120 at the predetermined distance can be referred to as a slot 130. The coating liquid L contained in the receiving portion 111 can be discharged to the outside through the slot 130.

[0053] The receiving portion 111 can transfer the coating liquid L contained in the internal space to the slot 130. The opening P of the receiving portion 111 can be an open area or an open space through which the receiving portion 111 opens toward the slot 130. The opening P can represent a virtual plane perpendicular to the X-axis through which the coating liquid L stored in the receiving portion 111 ultimately passes before reaching the slot 130. (Refer to...) Figure 2 The opening P can have an approximately rectangular shape and can have a predetermined horizontal length H and a predetermined vertical length V. The horizontal length H of the opening P can also be called the width, and the vertical length V can also be called the height.

[0054] The slot 130 can be defined as the space between the first block 110 and the second block 120, and can be configured to receive the coating liquid L from the receiving portion 111 and discharge it to the outside.

[0055] The width A1 of the slot 130 is the same as the distance between the first block 110 and the second block 120, and when the first block 110 and the second block 120 are parallel to each other, the width A1 of the slot 130 can be kept constant along the +Z axis direction. The coating liquid L conveyed from the receiving portion 111 to the slot 130 can move along the -Z axis direction due to gravity and can be discharged from the lower end of the slot 130 (the end along the -Z axis direction) toward the coating body B. In this case, the lower end of the slot 130 from which the coating liquid L is discharged can be referred to as the outlet 131. The outlet 131 can be provided at the end of the slot 130 in the -Z axis direction. The outlet 131 can be a part of the slot 130 and can be the last area through which the coating liquid L discharged from the coating unit 100 passes. The coating unit 100 can discharge the coating liquid L onto the coating body B through the outlet 131.

[0056] A plate gasket 140 can be disposed in a slot 130 to close a portion of the opening P of the receiving portion 111. The plate gasket 140 can be disposed in the slot 130 to mate between the first piece 110 and the second piece 120. To ensure stable assembly of the plate gasket 140 into the slot 130, the width A1 of the slot 130 and the thickness A2 of the plate gasket 140 can be approximately the same (see [reference]). Figure 1 (Enlarged view in the image). The first block 110 and / or the second block 120 may also include constructions such as convex and concave structures (not shown) to allow the plate gasket 140 to be secured.

[0057] The plate gasket 140 can be configured to alter the flow of coating liquid L from the receiving portion 111 to the slot 130 by closing a portion of the opening P of the receiving portion 111. The plate gasket 140 closing a portion of the opening P indicates that a portion of the opening P is covered to restrict the flow of coating liquid L through the covered portion into the slot 130.

[0058] The coating liquid L can flow from the opening P of the receiving portion 111 to the slot 130 through the portion not covered by the plate gasket 140. The components of the coating apparatus 1 can be as follows: Figure 1 The arrangement is shown, and the direction of gravity can be approximately the same as the -Z axis direction.

[0059] The interior of the receiving portion 111 can be configured such that the coating liquid L can move to the slot 130 due to gravity. For example, refer to Figure 1 The enlarged view shows that an inclined surface can be formed on the lower side (in the -Z axis direction) inside the receiving portion 111, and this inclined surface can cause the coating liquid L contained in the receiving portion 111 to flow to the slot 130 provided on the lower left side due to gravity.

[0060] The coating liquid L can flow to the lower left side (i.e., to the slot 130) due to gravity through the area not closed by the plate gasket 140, while preventing it from flowing through the area closed by the plate gasket 140.

[0061] The plate gasket 140 can close different parts of the opening P of the receiving part 111 according to its shape.

[0062] For example, refer to Figure 2 The plate gasket 140 may include a width limiting portion 141 configured to close a portion of the opening P of the receiving portion 111 from at least one of its two ends in the horizontal direction (Y-axis direction). The width limiting portion 141 may limit the width of the opening P to limit the coating width of the coating liquid L discharged from the receiving portion 111. The width of the coating liquid L discharged when its width is limited by the width limiting portion 141 may correspond to the coating width of the coating body B.

[0063] In addition, refer to Figure 2 The plate gasket 140 according to an embodiment of the present disclosure may include a height limiting portion 142 configured to close a portion of the opening P of the receiving portion 111 in the vertical direction (Z-axis direction). The height limiting portion 142 may limit the open area of ​​the opening P, thereby changing the pressure applied to the coating liquid L discharged from the receiving portion 111.

[0064] Reference Figure 2 According to the embodiments of the present disclosure, the width limiting portion 141 can be provided at each of the horizontal ends of the receiving portion 111. According to the above configuration, the height limiting portion 142 can be provided between the two width limiting portions 141 respectively provided at the horizontal ends of the receiving portion 111. However, this is merely an example, and the width limiting portion 141 can be provided at only one horizontal end of the receiving portion 111.

[0065] Roller 200 may include roller body 210 and rotating shaft 220. Roller body 210 of roller 200 may be positioned at a predetermined distance from slot 130. (See reference...) Figure 1 The roller body 210 can be positioned at a predetermined distance from the slot 130 in the downward direction (-Z-axis direction). The roller 200 can be rotated in one direction (by rotating the roller body 210). Figure 1 The coating body B is continuously transported along the X-axis direction, and the coating liquid L can be discharged onto the coating body B as the roller body 210 rotates, thereby coating the coating body B.

[0066] As described above, the coating body B can be an electrode to be used in the battery, and the coating liquid can be an electrode slurry for coating the electrode. The battery can be a rechargeable battery. When the slurry is coated onto the positive electrode, the slurry can include at least one of layered crystal structure lithium cobalt oxide (LiCoO2), lithium manganese oxide (such as layered crystal structure LiMnO2 or spinel crystal structure LiMn2O4), and lithium nickel oxide (LiNiO2) as the positive electrode active material. When the slurry is coated onto the negative electrode, the slurry can include a carbon-based material as the negative electrode active material, and can also include a silicon-based material or a silicon oxide-based material with an effective capacity 10 times higher than that of the carbon-based material.

[0067] In the following text, reference will be made to Figure 3 The plate gasket 140, the width limiting portion 141, and the height limiting portion 142 are described in more detail.

[0068] Figure 3 This is a conceptual diagram showing a plate pad of a coating apparatus according to an embodiment of the present disclosure.

[0069] Figure 3 It shows along Figure 1 The plate gasket 140, coating liquid L, and coating body B are shown in the section I-I', which are cut off and observed. For ease of explanation, Figure 3 The coating is concentrated on the plate gasket 140, the coating liquid L, and the coating body B, but does not include other components of the coating apparatus 1. Therefore, the rejection element of the coating apparatus 1 may also be included in the implementation configuration of this embodiment.

[0070] Reference Figure 1 and Figure 2 The described receiving part 111 from Figure 3 The details are omitted. However, the opening P of the receiving portion 111, having a horizontal length H and a vertical length V, is shown with dashed lines. Therefore, Figure 3 The positional relationship and arrangement of the opening P and the plate gasket 140 are shown. In addition, the inlet 112 is also shown in dashed lines within the opening P.

[0071] The opening P of the receiving portion can have a width as long as the horizontal length H and a height as long as the vertical length V. The opening P can be partially closed by a plate gasket 140.

[0072] As described above, the plate gasket 140 can change the flow pressure of the coating liquid L according to the shape or arrangement of the width limiting portion 141 and the height limiting portion 142, thereby changing the coating width or height of the coating liquid L on the coating body B.

[0073] Reference Figure 2 and Figure 3 The width limiting portion 141 can be provided at each of the two ends of the receiving portion 111 in the horizontal direction (Y-axis direction). Since the receiving portion 111 is open through the opening P, the width limiting portion 141 can be provided at both horizontal ends of the opening P.

[0074] Although the width of the opening P of the receiving portion 111 is H, the coating liquid L can be discharged to the upper surface of the coating body B through the area between the two width limiting portions 141 of the plate gasket 140, while the width of the coating liquid L is limited to H1 by the two width limiting portions 141, which is narrower than H.

[0075] Reference Figure 2 and Figure 3 A height limiting portion 142 can be disposed between two width limiting portions 141 disposed at the horizontal ends of the receiving portion 111. The height limiting portion 142 can be disposed between the width limiting portions 141, with a horizontal length H1 between them. The height of the height limiting portion 142 can vary along the horizontal direction (Y-axis direction). Depending on the profile of the vertical length of the height limiting portion 142 varying along the horizontal direction of the plate pad 140, the pressure applied when the coating liquid L is discharged into the coating body B can vary.

[0076] The vertical length of the height limiting portion 142 can limit the vertical length (i.e., height) of the discharged coating liquid L. For example, Figure 3 V1 in the figure represents the vertical length of the height-limiting section 142 at its center. V3 is obtained by subtracting V1 from the height V of the opening P.

[0077] Although the height of the opening P of the receiving portion 111 is V, the coating liquid L can be discharged to the upper surface of the coating body B through the lower region of the height limiting portion 142 of the plate gasket 140, while the height of the coating liquid L is limited by the height limiting portion 142 having a height V1 less than V at the center.

[0078] As described above, the height of the coating body B varies according to the shape of the lower end (in the -Z axis direction) of the height limiting portion 142, and the lower end of the height limiting portion 142 can be referred to as the "edge". Therefore, the height of the coating body B can be determined according to the shape of the edge of the height limiting portion 142.

[0079] The shape of the edge of the height limiting section 142 can be configured to vary between segments along the length direction (Y-axis direction). For example, refer to... Figure 3 The height limiting portion 142 may include a straight portion 1421 and a curved portion 1422. In the straight portion 1421, the shape of edge E1 changes linearly along the horizontal direction, and in the curved portion 1422, the shape of edge E2 changes along the horizontal direction as a curve with a predetermined radius of curvature.

[0080] The straight section 1421 can be configured such that the height of the coating liquid L discharged onto the coating body B changes linearly along the horizontal length direction (Y-axis direction). The slope or angle of the straight section 1421 can have a fixed value.

[0081] The curved portion 1422 can be configured such that the height of the coating liquid L discharged onto the coating body B changes slightly along the horizontal length direction (Y-axis direction). The slope or angle of the curved portion 1422 can be continuously changed along the horizontal length direction.

[0082] Since the shape of the coating liquid L discharged onto the coating body B depends on the characteristics of the edge of the height limiting portion 142, the design of the shape, proportion, size, radius of curvature, or arrangement of the straight portion 1421 and the curved portion 1422 is very important. Embodiments of this disclosure aim to achieve a very uniform coating of the coating liquid L onto the coating body B based on the shape, proportion, size, radius of curvature, or arrangement of the straight portion 1421 and the curved portion 1422.

[0083] The plate spacer 140 can be configured to be replaceable. The plate spacer 140 can be configured to be detachable from the coating unit 100 for replacement. For example, one of the first block 110 or the second block 120 of the coating unit 100 can be detached from the other, allowing the plate spacer 140 to be separated. As another example, the coating apparatus 1 can be configured such that the plate spacer 140 can be separated from the coating unit 100 without separating other components of the coating unit 100.

[0084] When the plate gasket 140 is replaced, the coating width and shape of the coating liquid L can be changed, and thus the shape or characteristics of the coating can be changed. Therefore, when the material, size, or shape of the coating body B is changed, when the characteristics of the coating liquid L are changed, or when a specific coating shape is desired, the user of the coating equipment can obtain the desired coating characteristics by replacing the plate gasket 140 as needed.

[0085] The straight section 1421 can have a constant slope θ. (Refer to...) Figure 3 The slope θ can indicate the angle between the edges of adjacent width limiting portions 141 and straight portions 1421. The edges of the width limiting portions 141 can be approximately parallel to the vertical direction (Z-axis direction), and in this case, the slope θ of the straight portions 1421 can indicate the angle between the vertical direction and the straight portions 1421.

[0086] According to embodiments of this disclosure, the slope θ of the straight portion 1421 and the slope of the curved portion 1422 may differ at their boundary. Specifically, the slope of the tangent at the boundary point between the curved portion 1422 and the straight portion 1421 may differ from the slope θ of the straight portion 1421. Based on the configuration described above, the change in the discharge pressure of the coating liquid L, which varies along the horizontal direction of the curved portion 1422, can change more significantly at the boundary between the straight portion 1421 and the curved portion 1422.

[0087] Furthermore, the vertical length V of the straight portion 1421 can reach its maximum value at the boundary between the straight portion 1421 and the curved portion 1422, and can gradually decrease as it moves further away from the curved portion 1422 in the horizontal direction. According to the above embodiment, the straight portion 1421 can make the opening P larger as it moves further away from the curved portion 1422 in the horizontal direction.

[0088] Reference Figure 3 The straight portion 1421 can be disposed at each of the two ends of the height limiting portion 142 in the horizontal direction (Y-axis direction), and the curved portion 1422 can be disposed between the two straight portions 1421. Furthermore, the height limiting portion 142 can have a shape that is substantially symmetrical in the horizontal direction with respect to the horizontal centerline of the curved portion 1422. (See reference...) Figure 3 The height limiting portion 142 can be approximately symmetrical in the left-right direction with respect to the line V1 indicating the center height. The height limiting portion 142 with the above shape can improve the coating uniformity of the coating liquid L on the coating body B.

[0089] Meanwhile, the edge of the width limiting portion 141 can be configured to be approximately parallel to the vertical direction. This configuration allows the width limiting portion 141 to limit the width of the opening P without limiting its height, thus sharing its function with the height limiting portion 142.

[0090] For example, the slope θ of the straight portion 1421 can have an angle of approximately 60 to 85 degrees relative to the edge of the width limiting portion 141. According to an embodiment in which the edge of the width limiting portion 141 is approximately parallel to the vertical direction, the slope θ of the straight portion 1421 can have an angle of approximately 60 to 85 degrees relative to the vertical direction (-Z-axis direction). Improvements to the coating shape based on the aforementioned slope θ range will be described in more detail below with reference to other accompanying drawings.

[0091] The vertical length of the curved portion 1422 can reach a maximum value V1 at the horizontal center of the curved portion 1422 and a minimum value V2 at the boundary with the two straight portions 1421. More specifically, the vertical length of the curved portion 1422 can gradually decrease from the horizontal center V1 of the curved portion 1422 toward the two straight portions 1421.

[0092] Reference Figure 3 The vertical length of the curved portion 1422 gradually decreases from the horizontal center V1 toward the straight portions 1421 on both sides, and the vertical length of the straight portions 1421 also gradually decreases toward the width limiting portions 141 on both sides, so that the height limiting portion 1422 can be configured such that the vertical length gradually decreases from the horizontal center V1 toward the left and right sides.

[0093] According to the above construction, the opening P of the receiving portion 111 can have a vertical length (height) that varies along the horizontal direction (Y-axis direction). More specifically, the opening P can have a vertical length V3 at the horizontal center of the curved portion 1422, which is about 50% to 55% of the vertical length V4 at the boundary between the curved portion 1422 and the straight portion 1421. For example, the vertical length V3 at the horizontal center of the curved portion 1422 can be about 0.8 mm, and the vertical length V4 at the boundary between the curved portion 1422 and the straight portion 1421 can be about 1.6 mm.

[0094] According to the configuration described above, the plate gasket 140 can be configured to discharge the coating liquid L with the highest pressure at the center, and to discharge the coating liquid L with lower pressure on the left and right sides. Specifically, the height of the opening P at the horizontal center of the curved portion 1422 can be approximately half (50% to 55%) of the height of the opening P at the boundary between the curved portion 1422 and the straight portion 1421.

[0095] Furthermore, the horizontal length H2 of the curved portion 1422 can be approximately 4.5 to 5.5 times the horizontal length H3 of each straight portion 1421.

[0096] For example, the horizontal length H2 of the curved portion 1422 can be approximately 100 mm, and the horizontal length H3 of the straight portion 1421 can be approximately 20 mm. According to the configuration described above, if the straight portion 1421 is provided on both sides of the curved portion 1422, the total length H1 of the height limiting portion 142 can be approximately 140 mm. The coating apparatus 1, including the plate gasket 140 with the above configuration, can discharge a coating liquid L with a width of approximately 140 mm.

[0097] Figure 4 This is a conceptual diagram showing a plate gasket for a conventional coating device. Figure 5 This is a cross-sectional view showing the coating of an object according to conventional coating equipment. (Refer to...) Figure 4 and Figure 5 The following will explain the coating problem performed by conventional coating equipment.

[0098] Figure 4 A plate gasket 140 is shown for use in a conventional coating apparatus. (See reference...) Figure 4 In the plate pad 140 used in conventional coating equipment, the vertical length of the height limiting portion 142 remains approximately the same along the horizontal direction. In the conventional height limiting portion 142, the height V3 at the center and the heights V4 on both sides remain constant along the horizontal direction, so the coating liquid L discharged through the opening P can be constant along the width direction (Y-axis direction).

[0099] Figure 5 A cross-section of a coated body B coated with a coating liquid L is shown according to a conventional coating apparatus. The coating liquid L is coated on the upper surface of the coated body B. According to the conventional coating apparatus, the central portion of the coating liquid L is convex and rises, resulting in uneven coating along the Y-axis. This is due to the fact that the coating liquid L is concentrated in the center due to the surface tension of the coating liquid L. Furthermore, the ends of the coating liquid L show a slope that is too gentle, so that the wide sections cannot reach the height of the coating liquid L.

[0100] The coating apparatus 1 according to the embodiments of the present disclosure can solve the above-mentioned problem by applying a higher discharge pressure to the coating liquid L discharged from the center of the opening P, thereby forming a more uniform coating surface.

[0101] Figure 6 It is based on reference Figures 1 to 3 A cross-sectional view of a coated body coated by a coating apparatus according to an embodiment of the present disclosure. Figure 6 It is shown by including reference Figures 1 to 3 The coating apparatus 1 of the plate gasket 140 describes the coating liquid L applied to the coating body B.

[0102] Figure 6 It shows the use of Figure 3 The plate pad 140 shown applies the coating liquid L to the coating body B with a uniform height (or thickness). (Refer to...) Figure 6 As can be seen, when coating body B is coated using the coating apparatus of the present disclosure, the coating liquid L is coated onto the coating body B at a uniform height.

[0103] The coating apparatus of this disclosure can perform coating such that the central portion of the coating liquid L is flat and the coating surface is uniformly coated along the Y-axis direction. Furthermore, the ends of the coating liquid L exhibit a slope ratio... Figure 5 The coating surface shown is steeper, and the maximum thickness of the coating layer is reached more quickly, resulting in a relatively small portion that fails to reach the height of the coating liquid L.

[0104] For reference Figures 1 to 3 The plate gasket 140 can close a portion of the opening P. Specifically, the height limiting portion 141 is configured such that the height of the coating liquid L discharged through the outlet is not constant in the width direction (Y-axis direction), thereby causing the discharge pressure of the coating liquid L to vary along the width direction.

[0105] In particular, if the height V3 of the opening P at its horizontal center is limited by the height restriction portion 141 to be less than the height of other areas, the pressure of the coating liquid L passing through the horizontal center of the opening P can relatively increase when passing through the plate gasket 140. Since the coating liquid L flows from a high-pressure area to a low-pressure area, it can flow horizontally from the horizontal center of the opening P to both sides of the opening P with lower pressure, thus allowing the coating liquid L concentrated in the center to flow to both sides. Therefore, as... Figure 6 As shown, compared with conventional coating equipment 1, the coating equipment 1 according to the embodiments of the present disclosure can obtain coating results with excellent uniformity and smoothness.

[0106] Meanwhile, the coating body B can be an electrode to be used in the battery, and the coating liquid L can be an electrode slurry to be coated on the electrode. If the electrode slurry is coated on the electrode using the coating apparatus 1 according to an embodiment of the present disclosure, the uniformity and smoothness of the electrode slurry coated on the electrode can be improved, and the energy density of the battery including such an electrode can be increased.

[0107] Figure 7 and Figure 8 This is a diagram showing experimental coating results obtained from a coating apparatus according to an embodiment of the present disclosure.

[0108] The horizontal length H3 of the straight portion 1421, the horizontal length H2 of the curved portion 1422, their ratio, the slope θ of the straight portion 1421, the heights V3 and V4 of the opening P, and their ratio, as described in the embodiments of this disclosure, are numerical values ​​or ranges designed to perform coating with excellent uniformity and smoothness as described above. Based on the experimental results below, it can be seen that, compared to conventional coating equipment, coating results with significantly superior uniformity and smoothness can be obtained according to the numerical ranges of the configuration presented in the specification.

[0109] Figure 7 It shows the reference Figures 1 to 3 The cross-sections of the coating liquid L and the coating body B coated by the coating apparatus 1 according to an embodiment of the present disclosure are described.

[0110] exist Figure 7 In the middle, H3 is through reference Figure 3 The height-limiting portion 142 described above has a coating section H3, and H4 is a coating section extending inward from section H3 and having half the length of H3. For example, H3 may be a coating section having a length of approximately 20 mm from the edge, and H4 (which is the inner region of H3) may be a coating section having a length of approximately 10 mm, corresponding to half the length of H3.

[0111] D1 represents the average coating thickness in section H4, and D2 represents approximately 90% of the thickness corresponding to D1. The coating section with coating thicknesses from D1 to D2 can be considered as the area where the coating body B is uniformly coated to achieve the target thickness.

[0112] According to the coating apparatus of the present disclosure, the thickness of the coating layer's cross-section can increase from the edge inwards to reach a peak thickness, and then slightly decrease and increase again. D3 is the coating thickness at the peak point.

[0113] H5 represents the horizontal length from the coating peak to the point where the coating thickness first reaches D2. From H5 inwards ( Figure 7The coating portion (to the right of H5) is uniformly coated with a coating thickness of D1 to D2. Therefore, the shorter the length of H5, the flatter and more uniform the coating layer on the coating body B becomes.

[0114] Figure 8 It is a graph showing the results of coating experiments comparing conventional coating equipment with the improved coating equipment of this disclosure. Figure 8 The results of performing 10 coatings using conventional coating equipment and the results of performing 10 coatings using the improved coating equipment of this disclosure are shown.

[0115] according to Figure 8 The graph shown has a vertical axis representing a reference. Figure 7 The description of H5 values ​​shows the distribution of H5 values ​​based on coating results using conventional coating equipment and the distribution of H5 values ​​based on coating results using coating equipment according to embodiments of this disclosure.

[0116] According to the coating results of conventional coating equipment, the value H5 falls in the range of approximately 2.7 mm to 4.1 mm, with a median value of approximately 3.2 mm. On the other hand, based on the coating results of the coating equipment according to the embodiments of this disclosure, the value H5 falls in the range of approximately 1.9 mm to 2.8 mm, with a median value of approximately 2.4 mm.

[0117] Based on the coating experiment results, the coating results of the coating apparatus according to the embodiments of the present disclosure show that the H5 value is lower than that of conventional coating apparatus. Therefore, it can be evaluated that the coating apparatus according to the embodiments of the present disclosure can obtain a flatter and more uniform coating layer than conventional coating apparatus.

[0118] Figure 9 It is a graph showing a comparison of the cross-sections of the coatings between conventional coating equipment and the improved coating equipment of this disclosure.

[0119] Figure 9 The horizontal axis of the graph represents the horizontal length of the coating from the end to approximately 20 mm inward, and the vertical axis represents the thickness of the coating. Figure 9 The outline of the curve shown can resemble the outline of the cross-section of the coating.

[0120] Reference Figure 9 The graphs shown indicate that the coating results from conventional coating equipment exhibit a relatively gentle slope until reaching a flat section, resulting in a relatively insufficient flat area compared to the improved results. On the other hand, the coating results from the improved coating equipment according to this disclosure exhibit a relatively steep slope until reaching a flat section and a constant flat area, resulting in a wider flat area than that from conventional coating equipment.

[0121] As described above, although this disclosure has been described with reference to limited embodiments and accompanying drawings, this disclosure is not limited thereto, and various modifications and variations are possible within the scope of the technical concept of this disclosure and the equivalents of the claims to which those skilled in the art to which this disclosure pertains. Therefore, the scope of this disclosure should be interpreted by the draft claims to cover all modifications.

Claims

1. A coating apparatus, the coating apparatus comprising: The first block has a receiving portion that is opened through an opening having a predetermined horizontal length and a predetermined vertical length, and the receiving portion is configured to receive a coating liquid; The second block is spaced apart from the first block by a predetermined distance and is disposed opposite to the opening of the receiving portion; A slot, defined as the space between the first block and the second block, and configured to receive the coating liquid from the receiving portion and discharge the coating liquid to the outside; as well as A plate gasket, disposed in the slot and configured to close part of the opening of the receiving portion, thereby altering the flow of the coating liquid delivered from the receiving portion to the slot. The plate gasket includes a width limiting portion and a height limiting portion. The width limiting portion is configured to close a portion of the opening of the receiving portion in the horizontal direction from at least one of the horizontal ends of the receiving portion, and the height limiting portion is configured to close a portion of the opening of the receiving portion in the vertical direction.

2. The coating equipment according to claim 1, in, The plate gasket is configured to be replaceable.

3. The coating equipment according to claim 1, in, The width limiting portion is provided at each of the horizontal ends of the receiving portion, and The height limiting portion is positioned between the two width limiting portions.

4. The coating equipment according to claim 3, in, The height limiting portion includes a straight portion whose edge shape changes linearly along the horizontal direction and a curved portion whose edge shape changes along the horizontal direction with a curve having a predetermined radius of curvature.

5. The coating equipment according to claim 4, in, The vertical length of the straight portion reaches its maximum at the boundary between the straight portion and the curved portion, and gradually decreases as the straight portion moves further away from the curved portion in the horizontal direction.

6. The coating equipment according to claim 4, in, The straight section is provided at each of the horizontal ends of the height limiting section, and The curved portion is positioned between two straight portions.

7. The coating equipment according to claim 6, in, The height-limiting portion has a shape that is approximately symmetrical in the horizontal direction with respect to the horizontal centerline of the curved portion.

8. The coating equipment according to claim 7, in, The edges of the width-limiting portion are configured to be approximately parallel to the vertical direction, and The slope of the straight section has an angle of approximately 60 to 85 degrees relative to the edge of the width limiting section.

9. The coating equipment according to claim 7, in, The vertical length of the curved portion reaches its maximum value at the horizontal center of the curved portion and its minimum value at the boundary with the two straight portions.

10. The coating apparatus according to claim 9, in, The vertical length of the curved portion gradually decreases from the horizontal center of the curved portion toward the two straight portions.

11. The coating apparatus according to claim 10, in, The vertical length of the opening of the receiving portion at the horizontal center of the curved portion is approximately 50% to 55% of its vertical length at the boundary between the curved portion and the straight portion.

12. The coating apparatus according to claim 7, in, The horizontal length of the curved portion is approximately 4.5 to 5.5 times the horizontal length of each of the straight portions.

13. The coating equipment according to claim 1, in, The width of the slot is approximately the same as the thickness of the plate gasket.

14. The coating equipment according to claim 1, The coating apparatus further includes a roller configured to transport the coating material by rotation of the roller body and positioned at a predetermined distance from the slot. in, The slot is configured to discharge the coating liquid onto the coating body as the roller rotates, thereby coating the coating body.

15. The coating apparatus according to claim 14, in, The coating is an electrode to be used in the battery, and The coating liquid is an electrode slurry used to coat the electrode.

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