Electrode slurry control device

Abstract

The present application relates to an electrode slurry control device including: a main body having a receiving port configured to receive an electrode slurry from an external storage portion; an applicator configured to discharge the electrode slurry onto a substrate; a supply pipe configured to supply the electrode slurry in the main body to the applicator and connected to the main body through a first connection pipe having a first opening / closing member; a first circulation pipe configured to move a portion of the electrode slurry introduced into the main body to the storage portion and connected to the main body through a second connection pipe having a second opening / closing member; and a second circulation pipe configured to move a portion of the electrode slurry in the main body to the storage portion and connected to the main body through a third connection pipe having a third opening / closing member, wherein an average diameter of an inner circumferential surface of the second connection pipe is smaller than an average diameter of an inner circumferential surface of the first circulation pipe, and wherein an average diameter of an inner circumferential surface of the third connection pipe is greater than the average diameter of the inner circumferential surface of the second connection pipe.

Description

Technical Field

[0001] This application claims priority and benefit to Korean Patent Application No. 10-2021-0155725, filed on November 12, 2021, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference.

[0002] This application relates to an electrode slurry control device. Background Technology

[0003] Recently, rising energy prices due to the depletion of fossil fuels and increasing concerns about environmental pollution have led to a growing demand for environmentally friendly alternative energy sources. Consequently, research into various power generation technologies, such as nuclear, solar, wind, and tidal power, is ongoing. Furthermore, there is significant interest in power storage devices for the more efficient use of such generated energy.

[0004] In particular, with technological advancements and increasing demand for mobile devices, the need for batteries as an energy source is rapidly growing. To meet these demands, numerous studies are being conducted on batteries.

[0005] Typically, regarding battery shape, there is a high demand for angled or pouch-shaped secondary batteries that can have a smaller thickness and are suitable for products such as mobile phones. Regarding materials, there is a high demand for lithium-ion batteries or lithium-ion polymer batteries that offer advantages such as high energy density, high discharge voltage, and high output stability.

[0006] Typically, a secondary battery is constructed as an electrode assembly comprising stacked positive and negative electrodes and a separator between the positive and negative electrodes. The positive and negative electrodes are each manufactured by applying a slurry containing active material onto a current collector.

[0007] The ink is supplied from the ink storage unit to the coating apparatus and coated onto the substrate. In the case of continuous coating, the ink can be supplied continuously. When changing the substrate or when it is necessary to form a pattern with coated and uncoated areas on the substrate, the ink can be supplied intermittently.

[0008] In this case, a device is needed to control the process of supplying and stopping the slurry, so as to temporarily supply the slurry continuously or stop the slurry supply as needed. When more precise patterns are required, precise control of the process of supplying and stopping the slurry is necessary. Summary of the Invention

[0009] Technical issues

[0010] This application aims to provide an electrode slurry control device.

[0011] Technical solution

[0012] One embodiment of this application provides an electrode slurry control device, comprising: a main body having a receiving port configured to receive electrode slurry from an external storage unit; a coating machine configured to discharge electrode slurry onto a substrate; a supply pipe configured to supply electrode slurry from the main body to the coating machine and connected to the main body via a first connecting pipe having a first opening / closing member; a first circulation pipe configured to move a portion of the electrode slurry introduced into the main body to the storage unit and connected to the main body via a second connecting pipe having a second opening / closing member; and a second circulation pipe configured to move a portion of the electrode slurry from the main body to the storage unit and connected to the main body via a third connecting pipe having a third opening / closing member, wherein the average diameter of the inner circumferential surface of the second connecting pipe is smaller than the average diameter of the inner circumferential surface of the first circulation pipe, and wherein the average diameter of the inner circumferential surface of the third connecting pipe is larger than the average diameter of the inner circumferential surface of the second connecting pipe.

[0013] In another embodiment of this application, when the first opening / closing member closes the first connecting pipe, the second opening / closing member can open the second connecting pipe, or the third opening / closing member can open the third connecting pipe, or the second opening / closing member and the third opening / closing member can respectively open the second connecting pipe and the third connecting pipe, and when the first opening / closing member opens the first connecting pipe, the second opening / closing member and the third opening / closing member can respectively close the second connecting pipe and the third connecting pipe.

[0014] In another embodiment of this application, the average diameter of the inner circumferential surface of the first connecting pipe may be smaller than the average diameter of the inner circumferential surface of the supply pipe, the first opening / closing member may have a conical shape, the diameter of the conical side surface facing the first connecting pipe may gradually decrease toward the first connecting pipe, and the cone angle of the conical side surface may be 110 degrees to 150 degrees.

[0015] In another embodiment of this application, the second opening / closing member may have a conical shape, the diameter of the conical side surface facing the second connecting pipe may gradually decrease toward the second connecting pipe, and the cone angle of the conical side surface may be 110 degrees to 150 degrees.

[0016] In another embodiment of this application, the third opening / closing member may be a ball valve with a through hole, and the average diameter of the inner circumferential surface of the third connecting pipe may be the average diameter of the through hole.

[0017] In another embodiment of this application, the electrode slurry control device may further include: a manifold connected to the first circulation pipe and the second circulation pipe, such that electrode slurry moving through the first circulation pipe to the body and electrode slurry moving through the second circulation pipe to the body are combined.

[0018] Beneficial effects

[0019] The electrode slurry control device according to this application can reduce the shear stress of the supplied electrode slurry.

[0020] The electrode slurry control device according to this application can uniformly control the load of the supplied electrode slurry. Attached Figure Description

[0021] Figure 1 This is a cycle diagram of an electrode slurry control device in related technologies.

[0022] Figure 2 This is a perspective view of an electrode slurry control device according to an embodiment of this application.

[0023] Figure 3 This is a cross-sectional view illustrating the state in which an electrode paste control device according to an embodiment of this application applies electrode paste to a substrate.

[0024] Figure 4 This is a cyclic diagram illustrating the state in which the electrode paste control device according to an embodiment of this application does not apply electrode paste to the substrate for a long period of time.

[0025] Figure 5 This is a cyclic diagram illustrating the state in which the electrode paste control device according to an embodiment of this application does not immediately apply electrode paste to the substrate during intermittent coating (pattern coating).

[0026] Figure 6 This is a cyclic diagram illustrating the state in which the electrode paste control device according to another embodiment of this application does not apply electrode paste to the substrate for a long period of time.

[0027] Figure 7 (a) is a diagram illustrating the state in which the cone valve, as an opening / closing component of the electrode slurry control device according to an embodiment of this application, is set in the positive position. Figure 7 (b) is a diagram illustrating the cone valve in the reverse position.

[0028] Figure 8 (a) is a diagram illustrating the flow rate change when a cone valve with a 90-degree cone angle is positioned in the connecting pipe in the positive position. Figure 8 (b) is a diagram illustrating the flow rate change when a cone valve with a cone angle of 120 degrees is positioned in the connecting pipe in the positive position.

[0029] Figure 9 (a) is a diagram illustrating the shear stress variation in a connecting pipe with a cone valve having a 90-degree cone angle in the positive position. Figure 9 (b) is a diagram illustrating the shear stress variation in a connecting pipe in which a cone valve with a cone angle of 120 degrees is positioned in the positive position.

[0030] Figure 10 (a) is a diagram illustrating the pressure change when a cone valve with a 90-degree cone angle is positioned in the connecting pipe in the positive position. Figure 10 (b) is a diagram illustrating the pressure change in a connecting pipe with a cone valve having a cone angle of 120 degrees in the positive position.

[0031] Figure 11 (a) is a diagram illustrating the flow rate change when a cone valve with a 90-degree cone angle is positioned in the connecting pipe in the opposite position. Figure 11 (b) is a diagram illustrating the flow rate change when a cone valve with a cone angle of 120 degrees is installed in a connecting pipe in the opposite position.

[0032] Figure 12 (a) is a diagram illustrating the change in shear stress in a connecting pipe with a cone valve having a 90-degree cone angle and positioned in the opposite direction. Figure 12 (b) is a diagram illustrating the shear stress variation in a connecting pipe with a cone valve having a cone angle of 120 degrees in the opposite position.

[0033] Figure 13 (a) is a diagram illustrating the pressure change in a connecting pipe with a cone valve having a 90-degree cone angle in the reverse position. Figure 13 (b) is a diagram illustrating the pressure change in a connecting pipe with a cone valve having a cone angle of 120 degrees in the reverse position.

[0034] Figure 14 It is a diagram. Figure 1 A diagram illustrating the change in slurry flow rate during a coating interruption period in an electrode slurry control device in the related technology, where the first opening / closing member is closed and the second opening / closing member is open.

[0035] Figure 15 It is a diagram. Figure 1 A diagram illustrating the change in shear stress applied to the slurry during a coating interruption period in an electrode slurry control device of the related technology, where the first opening / closing member is closed and the second opening / closing member is open.

[0036] Figure 16 It is a diagram. Figure 1A diagram illustrating the change in static pressure of the slurry in an electrode slurry control device in the related technology, during a coating interruption period when the first opening / closing member is closed and the second opening / closing member is open.

[0037] Figure 17 It is a diagram. Figure 6 A diagram illustrating the change in slurry flow rate during a long coating interruption period in a novel slurry control device, where the first opening / closing member is closed and the second and third opening / closing members are open.

[0038] Figure 18 It is a diagram. Figure 6 A diagram illustrating the change in shear stress in the slurry during a long coating interruption period in a novel slurry control device, where the first opening / closing member is closed and the second and third opening / closing members are open.

[0039] Figure 19 It is a diagram. Figure 6 A diagram illustrating the change in static pressure of the slurry during a long coating interruption period in a novel slurry control device, where the first opening / closing component is closed and the second and third opening / closing components are open.

[0040] <Label Explanation>

[0041] 100: Electrode slurry control device

[0042] 10: Main Body

[0043] 11: Receiver Port

[0044] 12: First opening

[0045] 13: Second opening

[0046] 14: Third opening

[0047] 20: Supply chain

[0048] 21: First opening / closing component; 22: First connecting pipe

[0049] 23: Conical side surface

[0050] 24: Second conical side surface

[0051] 25: First connecting member

[0052] 26: Second connecting member

[0053] 30: First circulation tube

[0054] 31: Second opening / closing component; 32: Second connecting pipe

[0055] 40: Second circulation pipe

[0056] 41: Third opening / closing component; 42: Third connecting pipe

[0057] 43: Ball

[0058] 44: Through hole

[0059] 45: Valve

[0060] 50: Combination tube

[0061] 60: Storage Department. Detailed Implementation

[0062] The invention will now be described in detail with reference to the accompanying drawings. However, the drawings are intended to illustrate the invention, and the scope of the invention is not limited by the drawings.

[0063] Figure 2 This is a perspective view of an electrode slurry control device 100 according to an embodiment of this application, and Figure 3 This is a cross-sectional view of an electrode slurry control device 100 according to an embodiment of this application.

[0064] The electrode slurry control device 100 includes a main body 10, a supply pipe 20, a first circulation pipe 30, and a second circulation pipe 40.

[0065] The main body 10 has a receiving port 11 formed at its end, and the receiving port 11 is configured to receive electrode paste from a storage section (not shown) for storing electrode paste. Furthermore, a first connecting pipe 22 connected to a first opening 12 of the main body 10 is opened or closed by a first opening / closing member 21. When the first connecting pipe 22 is open, the electrode paste in the main body 10 is supplied to a coating machine via a supply pipe 20, and the coating machine discharges the electrode paste onto a substrate. A second connecting pipe 32 connected to a second opening 13 of the main body 10 is opened or closed by a second opening / closing member 31. When the second connecting pipe 32 is open, the electrode paste in the main body 10 moves to the storage section via a first circulation pipe 30. A third connecting pipe 42 connected to a third opening 14 of the main body 10 is opened or closed by a third opening / closing member 41. When the third connecting pipe 42 is open, the electrode paste in the main body 10 moves to the storage section via a second circulation pipe 40.

[0066] The supply tube 20 is connected to a coating machine (not shown) configured to coat a substrate. The first circulation tube 30 is connected to the second opening 13 of the main body 10 and the storage section, and is configured to circulate the electrode paste to the external storage section.

[0067] In this case, the main body 10, the supply pipe 20 and the first circulation pipe 30 can be set in the form of cylindrical pipes, and the average diameter and shape of the main body 10, the supply pipe 20 and the first circulation pipe 30 can be freely changed, because the average diameter and shape can be freely designed by the designer as needed.

[0068] In this case, there are no particular restrictions on the substrate, as long as it can be coated with electrode paste. The substrate can be a current collector, specifically, a metal foil. The substrate can be a foil made of copper, aluminum, or a combination thereof.

[0069] Electrode slurry applied by a coating machine may include electrode active materials, binders, and solvents.

[0070] There are no particular restrictions on the electrode active material, as long as it is used for either the positive or negative electrode of the battery. For the positive electrode, the active material can be LCO (LiCoO2), NCM (Li(NiCoMn)O2), NCA (Li(NiCoAl)O2), LMO (LiMn2O), LFP (LiFePO4), etc. For the negative electrode, the active material can be carbon (graphite), etc.

[0071] There are no particular limitations on the adhesive, as long as it allows the electrode active material to solidify. The adhesive can be selected from those used in this technical field.

[0072] There are no particular restrictions on the solvent, as long as it provides flowability to the electrode paste. Solvents can be water, N-methylpyrrolidone, etc.

[0073] The supply pipe 20 is connected to the body 10 via a first connecting pipe 22. Therefore, the first connecting pipe 22 is located between the supply pipe 20 and the body 10. The average diameter r1 of the inner circumferential surface of the first connecting pipe 22 is smaller than the average diameter R1 of the inner circumferential surface of the supply pipe 20.

[0074] In addition, the average diameter of the outer circumferential surface of the first connecting pipe 22 can be equal to the average diameter of the outer circumferential surface of the supply pipe 20, so as to achieve convenience and stability when combining the first connecting pipe 22 and the supply pipe 20.

[0075] In this case, the first connecting tube 22 can be made of a metallic material with predetermined rigidity. Any material can be used, as long as it can withstand the pressure exerted by the supply of electrode paste.

[0076] The first circulation pipe 30 is connected to the main body 10 via the second connecting pipe 32. Therefore, the second connecting pipe 32 is located between the first circulation pipe 30 and the main body 10. The average diameter r2 of the inner circumferential surface of the second connecting pipe 32 is smaller than the average diameter R2 of the inner circumferential surface of the first circulation pipe 30.

[0077] In addition, the average diameter of the outer circumferential surface of the first circulation pipe 30 can be equal to the average diameter of the outer circumferential surface of the first circulation pipe 30, so as to achieve convenience and stability when combining the second connecting pipe 32 and the first circulation pipe 30.

[0078] In this case, the second connecting tube 32 can be made of a metallic material with predetermined rigidity. Any material can be used, as long as it can withstand the pressure exerted by the supply of electrode paste.

[0079] The second circulation pipe 40 is connected to the main body 10 via the third connecting pipe 42. Therefore, the third connecting pipe 42 is located between the second circulation pipe 40 and the main body 10.

[0080] The second circulation pipe 40 has a third opening / closing member 41. The average diameter of the inner circumferential surface of the third connecting pipe 42 is the average diameter of the hole opened by the third opening / closing member 41. For example, the third opening / closing member 41 may be a ball valve with a through hole. The average diameter r3 of the inner circumferential surface of the third connecting pipe 42 may be the average diameter r3 of the through hole. The average diameter r3 of the inner circumferential surface of the third connecting pipe 42 is equal to or less than the average diameter R3 of the inner circumferential surface of the second circulation pipe 40.

[0081] Furthermore, the average diameter of the outer circumferential surface of the third connecting pipe 42 can be equal to the average diameter of the outer circumferential surface of the second circulation pipe 40, so as to achieve convenience and stability when connecting the third connecting pipe 42 and the second circulation pipe 40. In order to achieve convenience and stability when connecting the third connecting pipe 42 and the second circulation pipe 40, the average diameter of the end of the third connecting pipe 42 connected to the second circulation pipe 40 can be equal to the average diameter of the outer circumferential surface of the second circulation pipe 40, and the average diameter of the outer circumferential surface of the portion where the third opening / closing member 41 is provided can be greater than the average diameter of the outer circumferential surface of the second circulation pipe 40.

[0082] In this case, the third connecting tube 42 can be formed of a metallic material with predetermined rigidity. Any material can be used, as long as it can withstand the pressure exerted by the supply of electrode paste.

[0083] A first opening / closing member 21 is disposed in the supply pipe 20 and configured to open or close the first connecting pipe 22. A second opening / closing member 31 is disposed in the first circulation pipe 30 and configured to open or close the second connecting pipe 32.

[0084] The shape of the second opening / closing member 31 may be the same as that of the first opening / closing member 21, and the size and average diameter of the second opening / closing member 31 may be different from those of the first opening / closing member 21. However, since the second opening / closing member 31 can open or close the second connecting pipe 32 according to the same principle as the first opening / closing member 21 that opens or closes the first connecting pipe 22, its repeated description will be omitted.

[0085] The first opening / closing member 21 has a conical side surface 23 facing the first connecting pipe 22. When the cone facing the first connecting pipe 22 and specifically defined by the conical side surface 23 is referred to as the first cone, a second conical side surface 24 may be formed and the second conical side surface 24 is positioned to correspond to the side opposite to the first cone.

[0086] The first opening / closing member 21 may be a cone valve with a conical shape, such that the diameter of the conical side surface 23 facing the first connecting pipe 22 gradually decreases outward.

[0087] In this case, the conical side surface 23 and the second conical side surface 24 each have a conical shape with a diameter that gradually decreases outward. In this case, the conical side surface refers to a curved surface defined by connecting the apex and the bottom circle of the cone.

[0088] Therefore, the first opening / closing member 21 has a single conical shape or a shape defined by joining the bottoms of two identical cones. When the first opening / closing member 21 has a shape defined by joining the bottoms of two identical cones, the conical shape of the conical side surface 23 and the conical shape of the second conical side surface 24 define a symmetrical structure.

[0089] In this case, the second conical side surface 24 of the first opening / closing member 21 can be sharply formed into a conical shape, or the apex of the second conical side surface 24 can be rounded.

[0090] The cone angle of the first opening / closing member 21 can be from 110 degrees to 150 degrees. Specifically, the cone angle of the first opening / closing member 21 can be from 110 degrees to 140 degrees, from 110 degrees to 130 degrees, or from 115 degrees to 125 degrees. Specifically, the cone angle of the first opening / closing member 21 can be 120 degrees.

[0091] Figures 8 to 13 This is a diagram illustrating a comparison of the flow rate, shear stress, and pressure of the electrode slurry when a cone valve with a 90-degree cone angle is open or closed, versus when a cone valve with a 120-degree cone angle is open or closed.

[0092] When the first opening / closing member 21 and the second opening / closing member 31 repeatedly reciprocate, the frictional resistance to the electrode slurry can be reduced.

[0093] Furthermore, the friction between the first opening / closing member 21 and the electrode paste can be reduced, thereby reducing the pressure of the electrode paste applied to the first opening / closing member 21 when it moves. This prevents malfunctions, minimizes the amount of electrode paste pushed upward to a position above the second conical side surface 24, and prevents the formation of areas where excessive coating is locally applied during the initial coating process.

[0094] Alternatively, the first opening / closing member 21 can be formed by joining the bottoms of two identical cones. Or, the first opening / closing member 21 can be initially manufactured in the same shape as defined by joining the bottoms of two identical cones, without joining the bottoms of the two identical cones.

[0095] However, depending on the type, viscosity and other properties of the electrode paste, the first on / off member 21 can be formed by combining the shapes defined by two cones that selectively have different average diameters.

[0096] Furthermore, the material of the first opening / closing member 21 may have a predetermined stiffness and be non-permeable, so as to perfectly block the electrode paste introduced into the supply pipe 20 through the first connecting pipe 22. Specifically, the material of the first opening / closing member 21 may be, but is not limited to, a metallic material.

[0097] Additionally, the first opening / closing member 21 further includes a first connecting member 25 connected to the drive unit (not shown). The second opening / closing member 31 further includes a second connecting member 26 connected to the drive unit (not shown).

[0098] The first connecting member 25 and the second connecting member 26 can be arranged in the form of a strip. When power is transmitted to the first connecting member 25 and the second connecting member 26 through the drive unit, the first opening / closing member 21 and the second opening / closing member 31 can move.

[0099] In this configuration, the first connecting member 25 and the second connecting member 26 may each possess a rigidity sufficient to withstand the pressure applied to the body 10 by the electrode paste. Specifically, the first connecting member 25 and the second connecting member 26 may each be made of a metallic material.

[0100] Furthermore, the first connecting member 25 and the second connecting member 26 may each have a thickness much smaller than the average diameter of the inner circumferential surface of each of the first connecting tube 22 and the second connecting tube 32. This is to prevent the first connecting member 25 and the second connecting member 26 from occupying a large volume in the first connecting tube 22 and the second connecting tube 32, and to minimize the influence of the movement of the first connecting member 25 and the second connecting member 26 on the movement of the electrode paste.

[0101] Figure 3 This is a diagram illustrating the operating state of the electrode slurry control device with the supply pipe 20 open and the first circulation pipe 30 and the second circulation pipe 40 closed. Figure 4 This is a diagram illustrating the operating state of the electrode slurry control device with the supply pipe 20 and the first circulation pipe 30 closed and the second circulation pipe 40 open. Figure 5 This is a diagram illustrating the operating state of the electrode slurry control device with the supply pipe 20 and the second circulation pipe 40 closed and the first circulation pipe 30 open. Figure 6 This is a diagram illustrating the operating state of the electrode slurry control device with the supply pipe 20 closed and the first circulation pipe 30 and the second circulation pipe 40 open.

[0102] like Figure 2 and Figure 3 As shown, the first connecting member 25 connected to the drive unit (not shown) causes the first opening / closing member 21 to open or close the first connecting pipe 22, and the second connecting member 26 causes the second opening / closing member 31 to open or close the second connecting pipe 32.

[0103] The third opening / closing member 41 can be a ball valve with a through hole 44. A ball 43 with a through hole 44 can be provided in the third connecting pipe 42, and the ball 43 can be rotated by a valve 45 coupled to the outer surface of the ball 43. Figure 4 and Figure 6 As shown, the through hole 44 opens when it is positioned to connect with the second circulation pipe 40 due to the rotation of the ball 43. Figure 3 and Figure 5 As shown, when the through hole 44 is not connected to the second circulation pipe 40 due to the rotation of the ball, the through hole 44 is closed.

[0104] In this configuration, when the first opening / closing member 21 closes the first connecting pipe 22, at least one of the third connecting pipe 42 and the second connecting pipe 32 is opened via the third opening / closing member 41 and / or the second opening / closing member 31. When the first opening / closing member 21 opens the first connecting pipe 22, the second opening / closing member 31 closes the second connecting pipe 32, and the third opening / closing member 41 closes the third connecting pipe 42.

[0105] Specifically, refer to Figure 4 , Figure 5 and Figure 6The conical side surface 23 of the first opening / closing member 21 is inserted into the first connecting tube 22 while in close contact with it. As the conical side surface 23 of the first opening / closing member 21 is inserted into the first connecting tube 22 in close contact with it, the first connecting tube 22 closes. The position of the first opening / closing member 21 when the movement of the electrode paste to the supply tube 20 is blocked can be defined as the "first position".

[0106] Reference Figure 3 The entire conical side surface 23 of the first opening / closing member 21 is withdrawn from the first connecting pipe 22. When the first connecting pipe 22 is open and the electrode paste can be moved to the supply pipe 20, the position of the first opening / closing member 21 can be defined as the "second position".

[0107] In addition, such as Figure 3 and Figure 4 As shown, when the second opening / closing member 31 is inserted into the second connecting pipe 32 while in close contact with it, and the second connecting pipe 32 is closed, the position of the second opening / closing member 31 can be defined as the "third position". For example, in Figure 5 and Figure 6 As shown, when the second opening / closing member 31 is completely removed from the second connecting pipe 32 and the second connecting pipe 32 is open, the position of the second opening / closing member 31 can be defined as the "fourth position".

[0108] That is, the first position of the first opening / closing member 21 can correspond to the third position of the second opening / closing member 31, and the second position of the first opening / closing member 21 can correspond to the fourth position of the second opening / closing member 31.

[0109] In addition, such as Figure 3 and Figure 5 As shown, when the third opening / closing member 41 is inserted into the third connecting pipe 42 while in close contact with it, and the third connecting pipe 42 is closed, the position of the third opening / closing member 41 can be defined as the "fifth position". Figure 4 and Figure 6 As shown, the position of the third opening / closing member 41 can be defined as the "sixth position" when the third opening / closing member 41 is rotated and the third connecting pipe 42 is open.

[0110] First, refer to Figure 5 and Figure 6The operating principle is described. The first opening / closing member 21 moves toward the first connecting tube 22, and then the conical side surface 23 of the first opening / closing member 21 is inserted into the first connecting tube 22 and thus located in the first position. The second opening / closing member 31 moves toward the side opposite to the second connecting tube 32, and then the conical side surface 23 of the second opening / closing member 31 is completely withdrawn from the second connecting tube 32 and thus located in the fourth position. In this case, the third opening / closing member 41 can be located in the fifth position, i.e. Figure 5 The closed state shown may be located in the sixth position, i.e. Figure 6 The open state is shown in the image.

[0111] Conversely, refer to Figure 3 The first opening / closing member 21 moves toward the side opposite to the first connecting tube 22, and then the conical side surface 23 of the first opening / closing member 21 is completely withdrawn from the first connecting tube 22 and thus located in the second position. The second opening / closing member 31 moves toward the second connecting tube 32, and then the conical side surface 23 of the second opening / closing member 31 is inserted into the second connecting tube 32 and thus located in the third position. The third opening / closing member 41 is located in the fifth position, i.e., the closed state.

[0112] Therefore, when the first connecting tube 22 is in the fully open state (second position), the second connecting tube 32 and the third connecting tube 42 are in the fully closed state (third and fifth positions). In this case, a coated portion is formed on the substrate. Furthermore, when the first connecting tube 22 is in the fully closed state (first position), the second connecting tube 32 is in the fully open state (fourth position), and the third connecting tube 42 is selectively opened or closed. In this case, an uncoated portion can be formed on the substrate.

[0113] That is to say, the first opening / closing member 21 and the second opening / closing member 31 can reciprocate at high speed in opposite directions and intermittently form coated and uncoated portions on the substrate under the control of the opening / closing members, without the need for complex control of the slurry supply pump.

[0114] In addition to the supply pipe 20, the electrode paste control device 100 has a separately provided first circulation pipe 30, which allows the electrode paste to be continuously circulated through the body 10 even when uncoated portions are formed on the substrate. This reduces the pressure applied to the body 10 even without stopping the operation of the paste supply pump.

[0115] When the second connecting tube 32 is in the fully open state (fourth position), the physical properties of the electrode slurry passing through the second connecting tube 32 change, which adversely affects the electrode coating quality. This is because the shape of the second opening / closing member 31 and the shape of the second connecting tube 32 apply high shear stress to the slurry.

[0116] Shear stress is a fundamental element in dispersing slurry during the mixing process, a step performed before coating. However, after the slurry is mixed, it is necessary to minimize shear stress. If additional shear force is unintentionally generated after the mixing process, two problems can arise.

[0117] First, shear stress adversely affects the interface of the slurry applied to the substrate. When shear stress is continuously applied to the slurry, the viscosity (viscosity profile) changes. In particular, the viscosity gradient of the viscosity profile (with an X-axis representing viscosity and a y-axis representing shear rate) affects the shape of the interface of the slurry applied to the substrate. If the coating interface cannot be managed, the proper ratio between the positive and negative electrodes in the finished lithium-ion battery is disrupted, which can lead to fire due to lithium deposition.

[0118] Secondly, when shear stress is applied under negative conditions via viscoelasticity, problems such as filter clogging (foreign matter filter installed in the slurry movement pipe) or coating quality degradation can occur. (Viscoelasticity refers to the viscosity and elasticity of a material). When shear force is applied under negative conditions, a particle network forms, which poses a risk of exhibiting solid properties. For this reason, problems of filter clogging or coating quality degradation exist.

[0119] To address the aforementioned problems, the purpose of this disclosure is to provide a method that additionally provides a second circulation pipe 40 and allows the slurry to bypass the second opening / closing member 31 and the second connecting pipe 32, which apply high shear stress to the slurry. Furthermore, the purpose of this disclosure is to improve the shapes of the first opening / closing member 21, the first connecting pipe 22, the second opening / closing member 31, and the second connecting pipe 32 to minimize shear stress.

[0120] To address this issue, in the event of a prolonged period of inactivity in coating, the third connecting tube 42 is switched to a fully open state (sixth position). This allows the slurry to bypass the second opening / closing member 31 and the second connecting tube 32, thus reducing shear stress and preventing changes in physical properties.

[0121] In the event of a prolonged coating stoppage, the third on / off member 41 and the third connecting pipe 42 can be opened. However, during intermittent coating (pattern coating), the slurry needs to be controlled by the first on / off member 21 and the second on / off member 31, which can be opened or closed at high speed, and the third connecting pipe 42 needs to be closed. Therefore, in the event of an immediate stoppage during intermittent coating, the slurry inevitably needs to pass through the second on / off member 31 and the second connecting pipe 32. In the event of coating, the slurry inevitably needs to pass through the first on / off member 21 and the first connecting pipe 22. This disclosure prevents changes in the physical properties of the slurry by minimizing the shear stress applied to the slurry by setting the cone angle of the on / off member to 110 to 150 degrees.

[0122] Model for implementing invention

[0123] Those skilled in the art will understand that the invention can be implemented in other specific forms without altering its technical spirit or essential features. Therefore, it should be understood that the above embodiments are illustrative in all respects and do not limit the invention. The scope of the invention is indicated by the claims, not by a detailed description, and it should be understood that the meaning and scope of the claims, and various embodiments derived from their equivalents, fall within the scope of the invention.

[0124] The present application will be described in more detail below with reference to examples. However, the following examples are intended to illustrate the present application, and the scope of the present application is not limited to the following examples.

[0125] [Experimental Example 1]

[0126] Flow velocity distribution

[0127] The effectiveness of this disclosure in minimizing the shear stress applied to the slurry was evaluated by performing flow analysis, which was conducted by setting the cone angle of the opening / closing member to 110 to 150 degrees. An opening / closing member with a cone angle of 90 degrees in the related art and an opening / closing member with a cone angle of 120 degrees according to this disclosure were compared and analyzed. The specific flow analysis method is as follows. One of the negative electrode slurries used in LG New Energy's cylindrical batteries was used as the working fluid. The viscosity profile of the slurry was obtained by actual measurement with a viscometer, then curve-fitted to a Carreau-Yasuda model, and input into the flow analysis program. Variables such as slurry density, slurry flow rate, valve size, and valve stroke (degree of valve opening) were selected to appropriately reflect the actual coating process. The analysis was performed under steady-state conditions using a turbulence model. The analysis tool used was Siemens STAR-CCM+. The results are in... Figure 8 and Figure 11 As shown in the image.

[0128] Figure 8 (a) is a diagram illustrating the flow rate change in a connecting pipe with a cone valve having a 90-degree cone angle in the positive position, and Figure 8 (b) is a diagram illustrating the flow rate change when a cone valve with a cone angle of 120 degrees is positioned in the connecting pipe in the positive position.

[0129] Figure 11 (a) is a diagram illustrating the flow rate change when a cone valve with a 90-degree cone angle is positioned in a connecting pipe in the opposite position. Figure 11 (b) is a diagram illustrating the flow rate change when a cone valve with a cone angle of 120 degrees is installed in a connecting pipe in the opposite position.

[0130] according to Figure 8 (b) and Figure 11 The results of the flow analysis shown in (b) show that, compared with Figure 8 (a) and Figure 11 Compared to the on / off member with a 90-degree cone angle shown in (a), using an on / off member with a 120-degree cone angle reduces the maximum flow velocity of the slurry. The shear stress applied to the fluid is (viscosity × shear strain rate). Generally, when other conditions are kept constant, the shear strain rate decreases as the flow velocity decreases. Therefore, it can be seen that the maximum shear stress applied to the slurry is further reduced when the cone angle is 120 degrees compared to when the cone angle is 90 degrees.

[0131] [Experimental Example 2]

[0132] Shear stress distribution

[0133] Similar to Experimental Example 1, flow analysis was performed to evaluate the effect of this disclosure in minimizing the shear stress applied to the slurry by setting the cone angle of the opening / closing member to 110 to 150 degrees. In this case, the shear stress was calculated as (slurry viscosity × slurry shear strain rate). The specific flow analysis method was the same as in Experimental Example 1. Figure 9 and Figure 12 The results show the distribution of shear stress applied to the slurry.

[0134] Specifically, Figure 9 (a) is a diagram illustrating the shear stress variation in a connecting pipe with a cone valve having a 90-degree cone angle in the positive position, and Figure 9 (b) is a diagram illustrating the shear stress variation in a connecting pipe where a cone valve with a 120-degree cone angle is positioned in the positive position. Furthermore, Figure 12(a) is a diagram illustrating the shear stress variation in a connecting pipe with a cone valve having a 90-degree cone angle in the opposite position, and Figure 12 (b) is a diagram showing the shear stress variation in a connecting pipe with a cone valve having a cone angle of 120 degrees in the reverse position.

[0135] from Figure 9 and Figure 12 As can be seen from the isometry diagram, the maximum shear stress applied to the slurry is further reduced when the cone angle is 120 degrees compared to when the cone angle is 90 degrees.

[0136] [Experiment Example 3]

[0137] Pressure loss distribution

[0138] In this experiment, flow analysis was performed to analyze the pressure loss when the cone angle was between 110 and 150 degrees. The specific flow analysis method was the same as in Experiment 1. Figure 10 and Figure 13 The results show the distribution of static pressure applied to the slurry.

[0139] Specifically, Figure 10 (a) is a diagram illustrating the pressure change when a cone valve with a 90-degree cone angle is positioned in the connecting pipe in the positive position. Figure 10 (b) is a diagram illustrating the pressure change when a cone valve with a 120-degree cone angle is positioned in the connecting pipe in the positive position. Furthermore, Figure 13 (a) is a diagram illustrating the pressure change when a cone valve with a 90-degree cone angle is positioned in the connecting pipe in the reverse position. Figure 13 (b) is a diagram illustrating the pressure change in which a cone valve with a cone angle of 120 degrees is set in a connecting pipe in the reverse position.

[0140] from Figure 10 and Figure 13 As shown in the contour plot, the pressure loss is further reduced when the cone angle is 120 degrees compared to when the cone angle is 90 degrees. Based on Experimental Examples 1 to 3, it can be determined that using an opening / closing member with a cone angle of 110 to 150 degrees can reduce the load on the slurry pump and make the opening / closing member move smoothly.

[0141] [Experiment Example 4]

[0142] Flow analysis in this experiment revealed the influence of a piping system in the related art, where the second circulation pipe 40 and the third on / off component 41 were not installed, on the slurry. A valve with a 90-degree cone angle, as used in the related art, was employed as the on / off component. The analysis area was the piping system with the first on / off component 21 closed and the second on / off component 31 open (during coating interruption). Flow analysis methods were the same as those used in Experimental Example 1 for all areas except the analysis area. Results were obtained in… Figure 14 , Figure 15 and Figure 16 As shown in the image. Figure 14 , Figure 15 and Figure 16 The velocity distribution, shear stress distribution, and static pressure distribution are shown respectively.

[0143] Figure 14 The contour plot shows a high flow rate occurring near the second on / off member during coating interruption. Therefore, Figure 15 This indicates that high shear stress occurs near the second opening / closing member. Figure 16 This shows that the second opening / closing component generates most of the pressure loss.

[0144] Therefore, it can be seen that when coating is stopped for a long period of time, it is additionally necessary to allow the slurry to bypass the second circulation pipe 40 of the second opening / closing member 31.

[0145] [Experiment Example 5]

[0146] Flow analysis in this experiment demonstrates the effect of the slurry control device, featuring a second circulation pipe 40 and a third on / off member 41, on the slurry. Similar to Example 4, the analysis area is the pipe system with the first on / off member 21 closed and the second on / off member 31 open (during coating interruptions). However, in this system, a second circulation pipe 40 is added, and the third on / off member 41 is opened, allowing the slurry to bypass the second on / off member 31. The flow analysis method for areas other than the analysis area is the same as that in Example 4. The analysis results are in... Figure 17 , Figure 18 and Figure 19 As shown in the image. Figure 17 , Figure 18 and Figure 19 The velocity distribution, shear stress distribution, and static pressure distribution are shown respectively.

[0147] Figure 17 This shows that most of the slurry flows through the second circulation pipe 40 and bypasses the second on / off member 31. Therefore, with Figure 15 compared to, Figure 18This shows a decrease in shear stress near the second opening / closing member. Furthermore, with... Figure 16 compared to, Figure 19 This shows a significant reduction in pressure loss (28.22 kPa → 12.01 kPa).

[0148] Therefore, it can be seen that the slurry control device with the second circulation pipe 40 and the third opening / closing member 41 can reduce the shear stress applied to the slurry and reduce the pressure loss of the piping system.

Claims

1.An electrode slurry control apparatus comprising: a main body having a receiving port configured to receive an electrode slurry from an external storage portion; an applicator configured to discharge the electrode slurry onto a substrate; a supply pipe configured to supply the electrode slurry in the main body to the applicator and connected to the main body through a first connection pipe having a first opening / closing member; a first circulation pipe configured to move a portion of the electrode slurry introduced into the main body to the storage portion and connected to the main body through a second connection pipe having a second opening / closing member; and a second circulation pipe configured to move a portion of the electrode slurry in the main body to the storage portion and connected to the main body through a third connection pipe having a third opening / closing member, wherein an average diameter of an inner circumferential surface of the second connection pipe is smaller than an average diameter of an inner circumferential surface of the first circulation pipe, wherein an average diameter of an inner circumferential surface of the third connection pipe is greater than the average diameter of the inner circumferential surface of the second connection pipe, wherein when the first opening / closing member closes the first connection pipe, the second opening / closing member opens the second connection pipe, or the third opening / closing member opens the third connection pipe, or the second opening / closing member and the third opening / closing member respectively open the second connection pipe and the third connection pipe, and wherein when the first opening / closing member opens the first connection pipe, the second opening / closing member and the third opening / closing member respectively close the second connection pipe and the third connection pipe. 2.The electrode slurry control apparatus of claim 1, wherein an average diameter of an inner circumferential surface of the first connection pipe is smaller than an average diameter of an inner circumferential surface of the supply pipe, and wherein the first opening / closing member has a conical shape, a diameter of a conical side surface facing the first connection pipe gradually decreases toward the first connection pipe, and a taper angle of the conical side surface is 110 to 150 degrees. 3.The electrode slurry control apparatus of claim 1, wherein the second opening / closing member has a conical shape, a diameter of a conical side surface facing the second connection pipe gradually decreases toward the second connection pipe, and a taper angle of the conical side surface is 110 to 150 degrees. 4.The electrode slurry control apparatus of claim 1, wherein the third opening / closing member is a ball valve having a through hole, and an average diameter of an inner circumferential surface of the third connection pipe is an average diameter of the through hole. 5.The electrode slurry control apparatus of claim 1, further comprising: a merging pipe connected to the first circulation pipe and the second circulation pipe such that the electrode slurry moved to the main body through the first circulation pipe and the electrode slurry moved to the main body through the second circulation pipe are merged. ​

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