Electrode coating device and electrode coating method

Abstract

An electrode coating apparatus and an electrode coating method are disclosed. The electrode coating apparatus according to one embodiment of the present invention includes a slot die coater for applying a slurry to a substrate, and an edge conditioner providing means for providing an edge conditioner for contacting the slurry to adjust protrusions formed at edges of the slurry.

Description

[Technical Field]

[0001] This application claims priority based on Korean Patent Application No. 10-2021-0156040, filed on November 12, 2021, and the entire contents disclosed in the specification and drawings of that application are incorporated herein by reference.

[0002] The present invention relates to an electrode coating apparatus and an electrode coating method, and more particularly to an electrode coating apparatus and an electrode coating method that can make the overall thickness of a slurry uniform. [Background technology]

[0003] Recent technological developments and increasing needs for mobile devices have been remarkable, and as a result, the need for secondary batteries as energy sources has grown rapidly. Such secondary batteries essentially include an electrode assembly, which is a power generation element.

[0004] The electrode assembly has a structure in which a positive electrode, a separator, and a negative electrode are stacked at least once. The electrodes, i.e., the positive electrode and the negative electrode, are fabricated by applying a positive electrode active material slurry and a negative electrode active material slurry, i.e., electrode slurry, to current collectors made of aluminum foil and copper foil, respectively, and then drying the applied slurry.

[0005] Fig. 1 is a diagram showing a state in which a slurry is applied to a substrate by a conventional electrode coating apparatus, where the substrate is a current collector.

[0006] 1, when a slurry 2 is applied to a substrate 1, a protrusion 3 is formed upward at the end of the slurry 2 due to surface tension, etc. If a protrusion 3 is formed at the end of the slurry, the overall thickness of the slurry becomes uneven, which reduces processability during the winding process and reduces the stability of the completed battery cell. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, the technical problem to be solved by the present invention is to provide an electrode coating apparatus and an electrode coating method that can remove protrusions formed at the edges of a slurry applied to a substrate and make the overall thickness of the slurry uniform. [Means for solving the problem]

[0008] According to one embodiment of the present invention, there is provided an electrode coating apparatus including: a slot die coater that applies a slurry to a substrate; and an edge conditioning material providing means that provides an edge conditioning material to the slurry so as to contact the slurry and condition protrusions formed on edges of the slurry.

[0009] Alternatively, the slurries may be provided in multiple layers, and the edge conditioning material may be provided between the multiple slurries.

[0010] Furthermore, the edge conditioning substance may be provided so as to attract the slurry by a difference in surface tension.

[0011] Furthermore, the edge conditioning material may be formed using the same solvent as the slurry, and the surface tension of the edge conditioning material may be set to be greater than the surface tension of the slurry.

[0012] Furthermore, the edge conditioning substance may contain a binder-based material having an adhesive strength within a preset range to prevent detachment after drying.

[0013] Furthermore, the edge adjustment material may include at least one of polytetrafluoroethylene (PTFE)-based, polyolefin-based, polyimide-based, polyurethane-based, polyester-based, polyvinylidenefluoride (PVDF)-based, styrene butadiene rubber (SBR)-based, ceramic-based, and silicon-based materials.

[0014] Furthermore, the slot die coater may include at least two die blocks, a shim plate disposed between the at least two die blocks and forming a slot connected to an outlet, and a manifold formed in at least one of the at least two die blocks and containing the slurry, and the edge adjustment material providing means may be formed in the shim plate.

[0015] Furthermore, the edge adjustment material supply means may be provided as a flow path formed on at least one side of the shim plate, and the edge adjustment material may be discharged into the slurry through the flow path formed in the shim plate.

[0016] Furthermore, the shim plate may include teeth, and the flow passage may be provided as a linear groove on one side of the shim plate teeth.

[0017] Furthermore, the edge adjustment material providing means may be an edge adjustment material coater that is provided separately from the slot die coater, positioned above or below the slot die coater, and configured to eject the edge adjustment material toward the substrate.

[0018] Meanwhile, according to another aspect of the present invention, there is provided an electrode coating method including the steps of applying a slurry to a substrate and providing the slurry with an edge conditioning material that contacts the slurry to condition protrusions formed on the edge of the slurry.

[0019] The method may also include providing a plurality of slurries, and providing the edge conditioning material between the plurality of slurries. [Effects of the Invention]

[0020] The present invention has an advantage that an edge conditioning material is provided to the slurry applied to the substrate, thereby removing protrusions formed at the edge of the slurry and making the overall thickness of the slurry uniform. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 1 is a diagram showing a state in which a slurry is applied to a substrate by a conventional electrode coating device. [Figure 2] 10A and 10B are diagrams illustrating a process in which an edge adjustment material is provided between the slurry to remove protrusions at the ends of the slurry and to make the overall thickness of the slurry uniform in accordance with an embodiment of the present invention. [Figure 3] 10A and 10B are diagrams illustrating a process in which an edge adjustment material is provided between the slurry to remove protrusions at the ends of the slurry and to make the overall thickness of the slurry uniform in accordance with an embodiment of the present invention. [Figure 4] 1 is a cross-sectional view of an electrode coating apparatus according to one embodiment of the present invention. [Figure 5] 1 is an exploded perspective view of an electrode coating apparatus according to an embodiment of the present invention; [Figure 6] FIG. 6 is a front view of the shim plate of FIG. 5. [Figure 7] FIG. 6 is a plan view of the shim plate of FIG. 5. [Figure 8] 10 is a cross-sectional view of an electrode coating apparatus according to another embodiment of the present invention. [Figure 9] FIG. 10 is a cross-sectional view of an electrode coating apparatus according to yet another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in terms and concepts that correspond to the technical ideas of the present invention, based on the principle that the inventor himself can appropriately define the concepts of terms in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely the most preferred embodiment of the present invention and do not represent the entire technical ideas of the present invention, and therefore, various equivalents and modifications that can be substituted therefor may exist at the time of filing this application.

[0023] In the drawings, the size of each component or specific parts of the component may be slightly exaggerated, omitted, or illustrated schematically for ease of explanation and clarity. Therefore, the size of each component does not fully reflect the actual size. If a detailed description of related well-known functions or configurations is deemed to be likely to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0024] The terms "coupled" or "connected" as used in this specification include not only cases where one member is directly coupled or connected to another member, but also cases where one member is indirectly coupled or connected to another member via a joint member.

[0025] 2 and 3 are diagrams showing the process of providing an edge adjustment material between the slurry to remove protrusions at the ends of the slurry and uniformize the overall thickness of the slurry in an electrode coating apparatus or electrode coating method according to one embodiment of the present invention; FIG. 4 is a cross-sectional view of an electrode coating apparatus according to one embodiment of the present invention; FIG. 5 is an exploded oblique view of an electrode coating apparatus according to one embodiment of the present invention; FIG. 6 is a front view of the shim plate of FIG. 5; FIG. 7 is a plan view of the shim plate of FIG. 5; FIG. 8 is a cross-sectional view of an electrode coating apparatus according to another embodiment of the present invention; and FIG. 9 is a cross-sectional view of an electrode coating apparatus according to yet another embodiment of the present invention.

[0026] In this specification, the substrate 300 is a current collector, and the slurry 400 is an electrode active material slurry.

[0027] Referring to the accompanying drawings, an electrode coating apparatus according to one embodiment of the present invention includes a slot die coater 100 and an edge conditioning material providing means 200 .

[0028] The slot die coater 100 is configured to apply the slurry 400 by discharging it onto the substrate 300 through the discharge port 150, thereby coating the substrate 300.

[0029] Referring to FIGS. 4 and 5, the slot die coater 100 includes die blocks 110 and 120, a shim plate 130, and a manifold 140.

[0030] There may be two or more die blocks 110 and 120, and as shown in FIGS. 4 and 5, two die blocks, a lower die block 110 and an upper die block 120, may be provided.

[0031] A shim plate 130 is provided between the lower die block 110 and the upper die block 120, thereby forming a slot 132. That is, the slot 132 is formed between the lower die block 110 and the upper die block 120 where they face each other, but the shim plate 130 may be interposed between the lower die block 110 and the upper die block 120 to provide a gap therebetween, thereby forming the slot 132 corresponding to a passage through which the slurry 400 can flow.

[0032] The lower die block 110 is disposed at the bottom, and the upper die block 120 is disposed above the lower die block 110. The lower die block 110 and the upper die block 120 are disposed such that the discharge port 150 faces the substrate 300 so that the slurry 400 is discharged toward the substrate 300. One of the die blocks 110, 120 is provided with a manifold 140 having a predetermined depth and communicating with the slot 132.

[0033] A freely rotatable coating roll 600 is arranged in front of the lower die block 110 and the upper die block 120. When the coating roll 600 rotates and the substrate 300 runs along the coating roll 600, the slurry 400 is applied to the substrate 300 through the discharge port 150 between the lower die block 110 and the upper die block 120, thereby coating the substrate 300.

[0034] The shim plate 130 is disposed between at least two die blocks 110 and 120 , for example, between the lower die block 110 and the upper die block 120 , and forms a slot 132 that communicates with the discharge port 150 .

[0035] Here, the discharge port 150 through which the slurry 400 is discharged to the outside is formed between the lower die lip 111, which is the tip of the lower die block 110, and the upper die lip 121, which is the tip of the upper die block 120. The discharge port 150 may be formed such that the die lips are spaced apart from each other.

[0036] In addition, the shim plate 130 may be made of a sealing material so as to function as a gasket to prevent the slurry 400 from leaking into the gap between the lower die block 110 and the upper die block 120, except for the area where the discharge port 150 is formed.

[0037] Here, the shim plate 130 may be formed with an edge adjusting material providing means 200, which will be described later.

[0038] The manifold 140 is formed in at least one of the at least two die blocks 110, 120 and is configured to accommodate the slurry 400. That is, the manifold 140 may be formed in the lower die block 110 or the upper die block 120.

[0039] The manifold 140 is connected to an external supply chamber (not shown) and a supply pipe (not shown) to receive the slurry 400. When the manifold 140 is filled with the slurry 400, the slurry 400 is guided to flow along the slots 132 and discharged to the outside through the discharge port 150.

[0040] The edge conditioner providing means 200 provides the edge conditioner 500 to the slurry 400 so as to come into contact with the slurry 400 and condition the protrusions 410 formed on the edges of the slurry 400 .

[0041] Here, the edge adjustment material 500 refers to a material that is provided to pull the slurry 400 due to a difference in surface tension. For example, the edge adjustment material 500 uses the same solvent as the slurry 400. The edge adjustment material 500 may include various materials that provide a surface tension of the edge adjustment material 500 that is greater than the surface tension of the slurry 400.

[0042] The edge conditioning substance 500 may include a binder-based material having a predetermined range of adhesive strength to prevent detachment after drying.

[0043] As a specific example, the edge adjustment material 500 may include at least one of polytetrafluoroethylene (PTFE)-based, polyolefin-based, polyimide-based, polyurethane-based, polyester-based, polyvinylidene fluoride (PVDF)-based, styrene butadiene rubber (SBR)-based, ceramic-based, and silicon-based materials.

[0044] Referring to FIG. 2, an edge conditioner 500 is provided between the plurality of slurries 400 so that the edge conditioner 500 contacts the ends of each of the plurality of slurries 400 .

[0045] 3, since the surface tension of the edge conditioning material 500 is greater than that of the slurry 400, the difference in surface tension between the edge conditioning material 500 and the slurry 400 acts to change the edge conditioning material 500 into a W-shape, and the upper protrusions 410 on both sides of the slurry 400 are pulled and removed by the edge conditioning material 500. As a result, the overall thickness of the slurry 400 is made uniform.

[0046] Here, various devices can be used as the device for providing the edge conditioning material 500 to the slurry 400. For example, in one embodiment, the edge conditioning material providing means 200 may be provided as a flow path 200a (see FIG. 5) formed on at least one side of the shim plate 130. In other words, the slot die coater 100 that provides the slurry 400 to the substrate 300 is provided so as to also provide the edge conditioning material 500.

[0047] Here, the edge adjusting material 500 may be supplied to the flow channel 200 a through a through-hole 700 formed in the upper die block 120 .

[0048] Alternatively, the edge conditioner 500 may be provided to the slurry 400 through the flow passages 200a formed in the shim plate 130. That is, the edge conditioner 500 may be discharged onto the substrate so as to come into contact with the slurry 400.

[0049] 5 to 7, the shim plate 130 includes teeth 131, and the flow path 200a may be provided as a linear groove on one side of the teeth 131 of the shim plate 130. Here, the teeth 131 may be provided in a center portion 131b and both side ends 131a and 131c, and the flow path 200a through which the edge conditioning material 500 moves may be formed in at least one of the center portion 131b of the teeth 131 and both side ends 131a and 131c of the teeth 131.

[0050] 2 and 3, a plurality of slurries 400 may be provided, and the edge conditioner 500 may be provided between the plurality of slurries 400. For example, if the edge conditioner 500 is provided through the center portion 131b of the tooth 131 in FIG. 5, it may be provided between the plurality of slurries 400.

[0051] However, the present invention is not necessarily limited to this, and the edge conditioning material 500 may be provided through both side ends 131a, 131c of the tooth 131 in Figure 5 so as to contact only one slurry 400.

[0052] As described above, the slurry 400 and the edge conditioning material 500 may be provided through a single slot die coater 100, or in another embodiment, the slot die coater 100 and the edge conditioning material 500 may be provided separately, and the slurry 400 and the edge conditioning material 500 may be provided separately.

[0053] 8, the edge conditioning material providing means 200 may be an edge conditioning material coater 200b, which is provided separately from the slot die coater 100 and disposed below the slot die coater 100. Here, the edge conditioning material 500 is discharged toward the substrate 300 before the slurry 400.

[0054] 9, the edge conditioner providing means 200 may also be an edge conditioner coater 200b, which is provided separately from the slot die coater 100 and disposed above the slot die coater 100. Here, the slurry 400 is first discharged toward the substrate 300, and then the edge conditioner 500 is discharged toward the substrate 300 so as to contact the slurry 400 later than the slurry 400.

[0055] 8 and 9, the edge adjustment material coater 200b has the same principle as the slot die coater 100 that discharges the slurry 400, and therefore a detailed description thereof will be substituted for the description of the slot die coater 100.

[0056] Additionally, various other devices may also be included as long as they are capable of providing the edge conditioning material 500 between the slurry 400 .

[0057] Meanwhile, the edge adjustment material 500 may be naturally cut and removed during the process of manufacturing the electrode, or may not need to be removed since the edge adjustment material 500 contains a material that forms the electrode.

[0058] Hereinafter, the operation and effects of the electrode coating device according to one embodiment of the present invention will be described with reference to the drawings.

[0059] Referring to Figures 5 to 7, the edge adjustment material providing means 200 may be provided as a channel 200a formed in the shim plate 130 of the slot die coater 100, and the edge adjustment material 500 is provided to the substrate 300 through the channel 200a formed in the shim plate 130 so as to come into contact with the slurry 400.

[0060] Meanwhile, in another embodiment, referring to FIG. 8, an edge adjustment material providing means 200 is provided separately from the slot die coater 100 and is positioned below the slot die coater 100 to provide the edge adjustment material 500, and in yet another embodiment, referring to FIG. 9, an edge adjustment material providing means 200 is provided separately from the slot die coater 100 and is positioned above the slot die coater 100 to provide the edge adjustment material 500.

[0061] Here, the edge adjustment material 500 provided to the slurry 400 has the same solvent as the slurry 400 but has a surface tension greater than that of the slurry 400, so it comes into contact with the slurry 400 and pulls the slurry 400, thereby removing the protrusions 410 formed at the ends of the slurry 400 and making the overall thickness of the slurry 400 uniform.

[0062] Hereinafter, the operation and effects of the electrode coating method according to an embodiment of the present invention will be described with reference to the drawings. However, the same description as that of the electrode coating apparatus according to the embodiment of the present invention will be replaced with the above-described description.

[0063] In addition, among the contents described in the electrode coating method according to one embodiment of the present invention, the contents that can be applied to the electrode coating apparatus according to one embodiment of the present invention also apply to the electrode coating apparatus according to one embodiment of the present invention.

[0064] Various methods can be used to provide the edge conditioner material 500 to the slurry 400. A device may be used, or the user may provide the edge conditioner material 500 to the slurry 400 by himself.

[0065] In the electrode coating method, a slurry 400 is applied to a substrate 300, and an edge conditioner 500 is provided on the slurry 400. The edge conditioner 500 comes into contact with the slurry 400 to smooth out protrusions 410 formed on the edges of the slurry 400. The order of application of the slurry 400 and the edge conditioner 500 may be reversed. That is, the slurry 400 may be first dispensed onto the substrate 300, and then the edge conditioner 500 may be provided onto the substrate 300 so that the edge conditioner 500 comes into contact with the slurry 400. Alternatively, the edge conditioner 500 may be first dispensed onto the substrate 300, and then the slurry 400 may be dispensed onto the substrate 300 so that the slurry 400 comes into contact with the edge conditioner 500. Alternatively, the slurry 400 and the edge conditioner 500 may be simultaneously dispensed onto the substrate 300.

[0066] Here, the slurry 400 may be provided in a plurality of layers, and the edge conditioning material 500 may be provided between the plurality of layers of the slurry 400 .

[0067] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited to these, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the scope of equivalents of the claims. [Industrial Applicability]

[0068] The present invention relates to an electrode coating apparatus and an electrode coating method for a secondary battery, and is particularly applicable to industries related to secondary batteries.

Claims

1. a slot die coater that applies the slurry to the substrate; an edge conditioner providing means for providing an edge conditioner to the slurry so as to contact the slurry and condition protrusions formed on the edge of the slurry; Including, The surface tension of the edge adjustment material is greater than the surface tension of the slurry, and the edge adjustment material pulls the slurry due to the difference in surface tension; An electrode coating apparatus, wherein the edge conditioning material is provided to the substrate after the slurry is first discharged onto the substrate.

2. The slurries are provided in plural, The electrode coating apparatus of claim 1 , wherein the edge conditioner is provided between a plurality of slurries.

3. The electrode coating apparatus according to claim 1 , wherein the edge conditioning material uses the same solvent as the slurry.

4. 4. The electrode coating apparatus according to claim 3, wherein the edge conditioning material includes a binder-based material having a predetermined range of adhesive strength to prevent detachment after drying.

5. 5. The electrode coating apparatus according to claim 4, wherein the edge conditioning material includes at least one of polytetrafluoroethylene (PTFE)-based, polyolefin-based, polyimide-based, polyurethane-based, polyester-based, polyvinylidene fluoride (PVDF)-based, styrene butadiene rubber (SBR)-based, ceramic-based, and silicon-based materials.

6. 2. The electrode coating apparatus according to claim 1, wherein the edge adjustment material providing means is an edge adjustment material coater that is provided separately from the slot die coater, is arranged above or below the slot die coater, and discharges the edge adjustment material toward the substrate.

7. applying a slurry to a substrate; providing an edge conditioner to the slurry, the edge conditioner contacting the slurry to condition any protrusions formed on the edge of the slurry; Including, The surface tension of the edge adjustment material is greater than the surface tension of the slurry, and the edge adjustment material pulls the slurry due to the difference in surface tension; An electrode coating method, wherein the edge conditioning material is applied to the substrate after the slurry is first dispensed onto the substrate.

8. The slurries are provided in plural, 8. The electrode coating method of claim 7, wherein the edge conditioner is provided between a plurality of slurries.

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