Slurry circulation system and method for electrode coating

Abstract

The present invention relates to a system for circulating slurry, comprising: a coating die for applying an electrode active material slurry on a current collector; a tank for supplying the electrode active material slurry to the coating die; and a circulation pipe for connecting the coating die and the tank, wherein the slurry is circulated through the circulation pipe at a line stop, the circulation pipe being connected to the tank from at least one of a left surface, a right surface, a rear surface, and a lower surface of the coating die.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 10-2021-0077884, filed on June 16, 2021, and Korean Patent Application No. 10-2022-0071892, filed on June 14, 2022, the entire contents of which are incorporated herein by reference.

[0002] This invention relates to a slurry circulation system for electrode coating capable of circulating slurry when a production line stops, and a slurry circulation method for electrode coating using the same system. Specifically, this invention relates to a slurry circulation system for electrode coating capable of circulating slurry when a production line stops by modifying the structure of the coating die, and a slurry circulation method for electrode coating using the same system. Background Technology

[0003] As the application of secondary batteries expands from small portable electronic devices to medium and large electric vehicles (EVs), energy storage systems (ESS), electric boats, and other applications, the demand for lithium secondary batteries with high capacity, high energy density, and long lifespan is growing rapidly.

[0004] Electrode manufacturing processes used to produce positive and negative electrodes are fundamental to the production of secondary batteries. These processes include coating, typically performed by applying an electrode slurry containing a mixture of active and conductive materials to a current collector and then drying it. A coating die apparatus can be used to perform the coating process with an electrode active material slurry supplied from a storage tank for electrode manufacturing. Furthermore, in the event of a line stop (stopping the coating process), there is no separate system for slurry circulation. Therefore, slurry residue in the coating die is prevented by draining it back to the supply storage tank via a return valve connected to the bottom of the die.

[0005] However, when the production line stops, residual slurry is discharged from the die through the return valve. Because the slurry does not circulate within the coating process system, including the storage tank and coating die, slurry agglomeration frequently occurs. Specifically, slurry agglomeration in the coating die causes macromolecular or gelation phenomena. When coating electrodes after the production line has stopped, surface defects such as pinholes or dents, or line defects where slurry is trapped between the C-roll and the coating die, appear. As a result, this leads to deteriorated coating quality and the handling of non-compliant electrodes, thus resulting in reduced electrode process yield and overall equipment effectiveness (OEE).

[0006] Therefore, in order to avoid the slurry from stagnating, clumping, or gelling in electrode coating equipment for secondary batteries, which would lead to a decrease in coating quality and productivity, it is necessary to develop systems and methods that can recycle the slurry even in the event of a production line stoppage in the coating process system, which includes slurry supply tanks and coating molds.

[0007] (Patent Document 1) Japanese Patent Publication No. 6280383, "Apparatus for Manufacturing Electrode Plates of Batteries" Summary of the Invention

[0008] Technical issues

[0009] To address the aforementioned problems, the inventors of this invention aim to provide a slurry circulation system for electrode coating that enables slurry circulation when the production line stops, and a slurry circulation method for electrode coating using the same system. This slurry circulation system can prevent slurry stagnation or agglomeration in the mold by continuously circulating the electrode active material slurry through the coating process system when the production line stops, and improves coating quality, process yield, and productivity by minimizing surface and line defects that may occur during electrode coating after the production line has stopped.

[0010] Technical solution

[0011] According to the first aspect of the invention, A slurry circulation system for electrode coating is provided, comprising: a coating mold for applying an electrode active material slurry to a current collector; a storage tank for supplying the electrode active material slurry to the coating mold; and a circulation pipe for connecting the coating mold and the storage tank, wherein the slurry circulation system is a system in which slurry is circulated through the circulation pipe when the production line stops, the circulation pipe being connected to the storage tank from at least one of a left surface, a right surface, a rear surface, and a lower surface of the coating mold.

[0012] In one embodiment of the invention, the slurry circulation system for electrode coating may be a system in which the slurry is circulated through the circulation pipe connected from the rear surface of the coating mold to the storage tank when the production line stops.

[0013] In one embodiment of the invention, the slurry circulation system for electrode coating may be a system in which the slurry is circulated through circulation pipes connected to the storage tank from the left and right surfaces of the coating mold, respectively.

[0014] In one embodiment of the present invention, the coating mold may include a manifold portion inside the mold.

[0015] In one embodiment of the invention, the slurry supply hole of the manifold portion connected to the interior of the mold is located on the lower surface of the coating mold, and the manifold portion may have a structure comprising: a first flow path including a hollow portion formed from the slurry supply hole in the direction of the upper surface; and a second flow path including hollow portions formed around one end of the first flow path in two lateral directions.

[0016] In one embodiment of the invention, the slurry circulation system for electrode coating is a system in which the connection hole for connecting the circulation pipe is located on at least one of the left surface, right surface, rear surface and lower surface of the coating mold, and when the production line stops, the electrode active material slurry supplied through the slurry supply hole moves through the slurry movement path in two lateral directions within the coating mold, and circulates to the storage tank through the circulation pipe connected to the connection hole.

[0017] In one embodiment of the invention, the slurry circulation system for electrode coating may further include: a pump for supplying the slurry from the storage tank to the coating mold; a filter; and a valve connected to the slurry supply port.

[0018] In one embodiment of the present invention, the coating mold may include a discharge section into which the slurry for electrode coating is discharged.

[0019] In one embodiment of the present invention, the coating mold may include a lip guard that can block and open the discharge portion.

[0020] In one embodiment of the present invention, the slurry circulation system for electrode coating may further include: a reflux valve; and a drain pipe connecting the reflux valve and the storage tank, wherein when the production line stops, the reflux valve may be opened so that a portion of the electrode active material slurry supplied from the storage tank is discharged into the storage tank through the drain pipe.

[0021] According to a second aspect of the present invention, the present invention provides a slurry circulation method for electrode coating using the slurry circulation system.

[0022] Beneficial effects

[0023] The slurry circulation system for electrode coating according to the present invention and the slurry circulation method for electrode coating using the slurry circulation system have the following effects: even when the production line stops when the coating process of the secondary battery is stopped, the system, in which the slurry is continuously circulated through the process including the storage tank and the mold without remaining in the mold, prevents macromolecular or gelation phenomena caused by slurry agglomeration in the mold, and minimizes coating quality defects during the coating process after the production line stops, thereby improving productivity.

[0024] Furthermore, the slurry circulation system for electrode coating and the slurry circulation method for electrode coating using the slurry circulation system according to the present invention have the following advantages: by providing a system that allows the slurry to circulate continuously, the process temperature in the coating mold can be kept constant even when the production line is stopped, and thus the coating process can be effectively performed without a separate process even after the production line has stopped.

[0025] Furthermore, the slurry circulation system for electrode coating according to the present invention and the slurry circulation method for electrode coating using the slurry circulation system can be applied to positive and negative electrode coating processes, and have the advantage of being able to respond regardless of the size of the current collector in the coating process using a slot die. Attached Figure Description

[0026] Figure 1 This is a schematic diagram illustrating the process of circulating and draining slurry during a routine production line stoppage in the electrode coating process during the manufacture of secondary batteries.

[0027] Figure 2 The images show (A) an internal photograph of the coating mold when it is opened after the production line stops, as is done in the prior art, and (B) a photograph of surface defects that appear during electrode coating after the stop.

[0028] Figure 3This is a schematic diagram illustrating the process of circulating and draining the slurry when the electrode coating process is stopped during the manufacture of a secondary battery.

[0029] Figure 4 An embodiment of a slurry circulation system for electrode coating according to the present invention is shown.

[0030] Figure 5 An embodiment of a slurry circulation system for electrode coating according to the present invention is shown.

[0031] Figure 6 This is a schematic diagram showing the structure in one embodiment of the slurry circulation system for electrode coating according to the invention, in which the circulation pipe is connected to the left or right surface of the coating mold.

[0032] Figure 7 This is a schematic diagram showing the structure of the circulation pipe connected to the left and right surfaces of the coating mold in one embodiment of the slurry circulation system for electrode coating according to the present invention.

[0033] Figure 8 This is a schematic diagram showing the structure in one embodiment of the slurry circulation system for electrode coating of the present invention, in which the circulation pipe is connected to the rear surface of the coating mold.

[0034] Figure 9 A schematic diagram illustrates a structure in which a circulation pipe is connected to the lower surface of a coating mold in one embodiment of a slurry circulation system for electrode coating according to the present invention.

[0035] Figure 10 The diagram illustrates the internal structure of the coating mold as it circulates through circulation pipes connected to the left and right surfaces of the coating mold in this invention.

[0036] Figure 11 The diagram illustrates the internal structure of the coating mold as it circulates through a circulation pipe connected to the rear surface of the coating mold in this invention.

[0037] Figure 12 The diagram illustrates the internal structure of the coating mold as it circulates through a circulation pipe connected to the lower surface of the coating mold in this invention.

[0038] Figure 13 The structure of the lip guard provided on the coating mold in this invention is shown.

[0039] Figure 14 The opening and closing structure of the lip guard provided in the coating mold of the present invention is shown.

[0040] Figure 15This is an enlarged view of the structure in which the discharge section and the lip guard section of the coating mold in this invention come into contact. Detailed Implementation

[0041] The following preferred embodiments are presented to aid in understanding the present invention, but these embodiments are provided only to facilitate a better understanding of the present invention, and the present invention is not limited thereto.

[0042] In addition, the size or shape of the components shown in the accompanying drawings may be enlarged for clarity and ease of explanation, and terms specifically defined in connection with the configuration and operation of the invention may be changed according to the intention or habit of the user or operator, and these terms should be defined based on the overall content of this specification.

[0043] The present invention will now be described in detail with reference to the accompanying drawings.

[0044] The inventors' experimental results show that in the conventional electrode coating process for manufacturing secondary batteries, since only a reflux valve is used to discharge the slurry remaining in the mold back to the storage tank when the production line stops, such as... Figure 1 As shown, there is a problem of the slurry in the coating mold becoming macromolecular or gelling due to agglomeration. This ultimately leads to a reduction in coating quality, and therefore also results in the cost of discarding electrodes that do not meet quality standards after production.

[0045] Specifically, see Figure 2 The diagram shows the inside of the coating die after the coating process has stopped, where the slurry has clumped together or a large amount of electrode powder is visible. It also highlights surface defects such as pinholes or dents and line defects where the slurry is trapped in the C-roll and coating die.

[0046] To address the aforementioned problems, the inventors of this invention have developed a slurry circulation system for electrode coating that enables slurry circulation when the production line stops, and a slurry circulation method for electrode coating using the same slurry circulation system. This slurry circulation system, by altering the structure of the coating mold, allows circulation pipes to be connected to the coating mold, enabling the slurry to circulate to a storage tank via circulation pipes connected to at least one of the left, right, rear, and lower surfaces of the mold. Furthermore, the slurry can circulate via at least one of the left, right, rear, and lower surfaces of the mold.

[0047] In one embodiment of the invention, the slurry circulation system for electrode coating is a system comprising: a coating mold 10 for applying electrode active material slurry to a current collector; a storage tank 20 for supplying electrode active material slurry to the coating mold; and a circulation pipe 30 for connecting the coating mold and the storage tank. This system allows the slurry to circulate through the circulation pipe 30, which is connected to at least one of the left, right, rear, and lower surfaces of the coating mold 10, when the production line is stopped.

[0048] In this specification, "line stop" refers to any situation in which the electrode coating process in the manufacture of secondary batteries is stopped for any reason.

[0049] In this specification, the left, right, rear, and lower surfaces of the coating mold 10 can be defined as the left, right, rear, and lower surfaces based on a front view of the lip end from which the slurry is discharged from the coating mold.

[0050] In one embodiment of the invention, the slurry circulation system for electrode coating includes a coating mold 10 for applying an electrode active material slurry to a current collector. In the electrode coating process, the electrode is coated by supplying an electrode active material slurry to the coating mold 10, then discharging it and applying it to the current collector, the coating mold 10 serving as a basic component for applying the electrode active material slurry to the current collector.

[0051] In one embodiment of the invention, the coating mold 10 may have a structure in which the structure of the slurry movement path inside the coating mold 10 is modified so that the slurry used for electrode coating can be circulated even when the production line is stopped, and the circulation pipe 30 is connected to at least one of the left surface, right surface, rear surface and lower surface of the coating mold.

[0052] like Figure 8 As shown, in one embodiment of the invention, the coating mold 10 may include a manifold 11 inside the mold. Compared to using an additional manifold to circulate the active material slurry, by incorporating a manifold 11 instead of adding an additional manifold, the invention has the following advantages: reduced costs due to changes in mold structure and coating process conditions, and avoidance of increased mold wear caused by non-uniform internal pressure of the mold during the coating process.

[0053] In one embodiment of the present invention, the slurry supply hole 12 of the manifold portion 11 connected to the mold is located on the lower surface of the coating mold 10, and the manifold portion 11 may have a structure including a first flow path and a second flow path. The first flow path includes a hollow portion formed in the direction from the slurry supply hole 12 to the upper surface, and the second flow path includes a hollow portion formed in two lateral directions around one end of the first flow path.

[0054] When the production line stops, the slurry supplied from the slurry supply hole 12 can move through the manifold 11 in the direction of the upper surface through the first flow path. Then, the slurry can circulate from one end of the first flow path to both sides through the second flow path to maintain the process temperature in the coating mold and to prevent the slurry from stagnating and clumping inside the coating mold. Figures 10 to 12 As shown, for example, the manifold 11 may have a structure in which a T-shaped slurry movement path is formed.

[0055] In this specification, a 'void section' can be defined as an empty space formed within the first and second flow paths of the manifold 11 for moving slurry.

[0056] like Figures 6 to 9 As shown, in one embodiment of the invention, the connection hole 13 for connecting the circulation pipe may be located on at least one of the left, right, rear, and lower surfaces of the coating mold. The configuration of the connection hole 13 allows the circulation pipe 30 leading to the storage tank 20 to be connected to the coating mold 10, and the shape of the connection hole 13 is not particularly limited, as long as it can connect to the circulation pipe 30. The diameter of the connection hole 13 for connecting the circulation pipe is preferably the same as the diameter of the slurry supply hole 12, but is not particularly limited thereto.

[0057] In one embodiment of the invention, the electrode coating slurry circulation system includes a storage tank 20 for supplying electrode active material slurry to a coating die. The storage tank 20 stores and supplies the electrode active material slurry, and is not particularly limited in this invention, as long as it is a storage tank capable of storing electrode active material slurry that can be recycled from the coating die when the production line stops, and the storage tank can be a conventional storage tank known in the art.

[0058] In one embodiment of the invention, the slurry circulation system for electrode coating includes a circulation line 30 for connecting the coating mold and the storage tank. For example... Figure 3As shown, the slurry circulation system for electrode coating connects the circulation pipe 30 from the coating mold 10 to the storage tank 20, so that the slurry can be continuously circulated through the circulation pipe 30 when the coating is stopped. The circulation pipe 30 is configured to connect to the connection hole 13 in the coating mold 10, and can be a pipe that can be easily detached and attached to the connection hole 13.

[0059] In one embodiment of the invention, the circulation pipe 30 can be a flexible pipe. Specifically, when the production line stops, the gap between the die and the C-roll widens. In this case, if a fixed type of circulation pipe is used, there may be problems with pipe separation or deformation. Therefore, to avoid these problems, a flexible type of pipe that can bend freely can be used instead of a fixed type of circulation pipe.

[0060] The larger the diameter of the circulation pipe 30, the higher the flow efficiency of the slurry. Therefore, preferably, a circulation pipe with a larger diameter can be used within a range that does not interfere with the fastening part of the mold.

[0061] like Figure 4 As shown, in one embodiment of the invention, the circulation conduit 30 may further include a valve before being connected to the storage tank 20. In another embodiment of the invention, the circulation conduit 30 may further include a pump for conveying slurry before being connected to the storage tank 20. The valve or pump located on the circulation conduit is not particularly limited in the invention and may be a conventional valve or pump known in the art.

[0062] In one embodiment of the invention, the slurry circulation system for electrode coating is a system in which slurry is circulated through a circulation pipe 30 when the production line is stopped. This circulation pipe 30 is connected to a storage tank 20 from at least one of the left, right, rear, and lower surfaces of the coating mold 10. In the case where the circulation pipe 30 is connected to the upper surface of the coating mold 10, unlike the left, right, rear, and lower surfaces of the coating mold 10, the flow direction of the slurry is formed from a direction with lower potential energy to a direction with higher potential energy. Therefore, gravitational resistance is generated, and it is relatively difficult to form a smooth slurry circulation flow. Furthermore, slurry leakage occurs at the lip of the mold.

[0063] In one embodiment of the invention, the slurry circulation system for electrode coating circulates the slurry by connecting circulation pipes to at least one of the left, right, rear, and lower surfaces of the coating mold, so as to minimize interference from the fastening portions depending on the location of the fastening portions used to fasten the upper and lower plates of the mold during the manufacturing process of the coating mold 10. For example, the circulation pipes may be connected to both the left and right surfaces of the coating mold, only to the lower surface, or only to the rear surface.

[0064] like Figure 4 and Figure 6 As shown, in one embodiment of the invention, the slurry circulation system for electrode coating can be a system in which the slurry is circulated through a circulation pipe 30 connected to at least one of the left and right surfaces of the coating mold 10 to the storage tank 20 when the production line stops.

[0065] like Figure 5 and Figure 7 As shown, the slurry circulation system for electrode coating can be a system in which the slurry is circulated through each circulation pipe 30 connected from the left and right surfaces of the coating mold 10 to the storage tank 20 when the production line stops. Specifically, the slurry circulation system can be a system in which the electrode active material slurry supplied through the slurry supply hole 12 moves in both lateral directions within the coating mold through the slurry movement path when the production line stops, and is circulated to the storage tank 20 through the circulation pipe 30 connected to the connection hole 13.

[0066] In one embodiment of the invention, when the electrode active material slurry moves in both lateral directions through the manifold 11 within the coating mold 10 and is then circulated to the storage tank 20 through circulation pipes 30 connected to the two sides, the slurry circulates uniformly in both lateral directions without deviation in each area within the coating mold. This prevents the slurry from agglomerating or gelling due to concentration in specific areas within the coating mold. Consequently, this has the following effects: preventing coating quality deterioration after production line shutdown; maintaining a constant process temperature between the left and right sides of the coating mold without deviation; and allowing the circulation status through the left and right pipes to be checked by installing thermometers, flow meters, or pressure gauges in the circulation pipes.

[0067] like Figure 8 and Figure 11As shown, in one embodiment of the invention, the slurry circulation system for electrode coating can be a system in which the slurry is circulated through a circulation pipe 30 connected from the rear surface of the coating mold 10 to the storage tank 20 when the production line stops. In the case where the slurry is circulated through the circulation pipe 30 connected from the rear surface of the coating mold 10 to the storage tank 20, compared to the case where the circulation valve is connected to other surfaces of the coating mold, the interference caused by the bolts connecting the upper and lower plates of the mold is less.

[0068] like Figure 9 and Figure 12 As shown, in one embodiment of the invention, the slurry circulation system for electrode coating can be a system in which the slurry is circulated through a circulation pipe 30 connected from the lower surface of the coating mold 10 to the storage tank 20 when the production line stops.

[0069] like Figures 10 to 12 As shown, in one embodiment of the invention, the circulation pipe 30 of the slurry circulation system for electrode coating can be connected to the left and right ends of the manifold 11 located inside the coating mold 10. Specifically, the circulation pipe 30 can be connected to the left and right ends of the second flow path located inside the coating mold 10. If the circulation pipe 30 is connected to the middle position rather than the two ends of the manifold, the flow rate decreases and slurry stagnation may occur due to low shear stress.

[0070] like Figure 14 As shown, in one embodiment of the invention, the coating mold 10 may be provided with a discharge section 14 to which electrode coating slurry is discharged, and a lip guard 15 capable of blocking or opening the discharge section 14 may be provided on the discharge section 14. The lip guard 15 is located at one end of a lip cover 16 to block or open the discharge section 14. This lip cover 16 is connected to a lip cutter shaft 17 and can be operated by a handle 18 to block or open the discharge section 14. The lip cover 16 or the lip cutter shaft 17 is not particularly limited, as long as it is made of a material that is not easily corroded and has sufficient rigidity to move the lip guard 15 and block the discharge section, and preferably, the lip cover 16 or the lip cutter shaft 17 may be made of a material such as SUS.

[0071] Specifically, when no electrode coating slurry is discharged, the lip guard 15 can block the discharge part 14, such as... Figure 14 As shown in (a). This not only prevents leakage of the electrode coating slurry but also avoids disrupting the overall circulation of the electrode coating slurry. Furthermore, when discharging the electrode coating slurry, the lip guard 15 should not obstruct the discharge section 14, as shown in (a). Figure 14 As shown in (b). Therefore, as Figure 15As shown, the lip guard portion 15 is in direct contact with the discharge portion 14, therefore, a lip guard contact portion 15-1 for preventing the discharge of electrode coating slurry and a lip guard fixing portion 15-2 for fixing the lip guard contact portion 15-1 are provided. The lip guard contact portion 15-1 may be made of an elastic material to completely block the discharge portion 14, but is not limited to this. The lip guard fixing portion 15-2 can also fix the lip guard contact portion 15-1 and may be made of, for example, plastic, but is not limited to this.

[0072] Additionally, in one embodiment of the invention, a protective film is formed on the lip guard portion 15 to protect it from solvents such as NMP. This protective film is not particularly limited, as long as it is not affected by solvents such as NMP, and for example, it can be a Teflon film or Teflon tape.

[0073] like Figure 4 and Figure 5 As shown, in one embodiment of the invention, the slurry circulation system for electrode coating may further include: a pump 40 for supplying slurry from the storage tank 20 to the coating mold 10; a filter 50; and a valve 60 connected to the slurry supply port 12. The electrode active material slurry supplied from the storage tank 20 is circulated under pressure from the pump 40 and may be sequentially conveyed to the filter 50 and the valve 60 for removing impurities, and then conveyed to the coating mold 10.

[0074] In one embodiment of the invention, pump 40 is not particularly limited, as long as it can deliver the electrode active material slurry, and can be a conventional pump known in the art. In one embodiment of the invention, filter 50 is not particularly limited, as long as it can filter the slurry during circulation of the electrode active material slurry, and can be a conventional pump known in the art. In one embodiment of the invention, valve 60 is not particularly limited, as long as it is configured to control the circulation of the electrode active material slurry by opening and closing, and can be a conventional pump known in the art.

[0075] In one embodiment of the invention, the slurry circulation system for electrode coating further includes a reflux valve 70 and a drain pipe 80 connecting the reflux valve and the storage tank. When the production line stops, a portion of the electrode active material slurry supplied from the storage tank 20 can be discharged into the storage tank 20 via the drain pipe 80 by opening the reflux valve 70. Independent of the circulation pipe 30, a portion of the electrode active material slurry can be drained when the production line stops through the reflux valve 70 and the drain pipe 80 located at the lower part of the coating die 10. This effectively prevents slurry leakage at the lip end of the coating die.

[0076] In one embodiment of the invention, the slurry circulation method for electrode coating uses the slurry circulation system described above. By circulating the slurry from at least one of the left, right, rear, and lower surfaces of the coating mold 10 to the storage tank 20 through a circulation pipe 30 connected to the storage tank 20 when the production line stops, and thus maintaining a constant internal temperature of the coating mold 10 without agglomeration or gelation caused by slurry stagnation in specific areas within the coating mold 10, surface defects or line defects after the production line stops are minimized. The slurry circulation method for electrode coating has the effect of improving coating quality and increasing process productivity.

[0077] All simple modifications or alterations to this invention fall within the scope of this invention, and the specific scope of protection of this invention will be defined by the appended claims.

[0078] [Symbol Explanation]

[0079] 10: Coating mold

[0080] 11: Manifold

[0081] 12: Slurry supply hole

[0082] 13: Connection hole for connecting circulation pipes

[0083] 14: Emissions Department

[0084] 15: Lip protector

[0085] 16: Lip Cover

[0086] 17: Lip blade axis

[0087] 18: Handle

[0088] 20: Storage tank

[0089] 30: Circulation Pipeline

[0090] 40: Pump

[0091] 50: Filter

[0092] 60: Valve

[0093] 70: Reflux valve

[0094] 80: Excretion pipe

Claims

1. A slurry circulation system for electrode coating, comprising: A coating die for applying an electrode active material slurry onto a current collector; A storage tank for supplying the electrode active material slurry to the coating mold; and A circulation pipe, which connects the coating mold and the storage tank. When the production line stops, the slurry circulates through the circulation pipe, which is connected to the storage tank from at least one of the left, right, rear, and lower surfaces of the coating die. The coating mold includes a manifold section inside the coating mold. The slurry supply hole connected to the manifold inside the coating mold is located on the lower surface of the coating mold, and The manifold has a structure including: a first flow path, the first flow path including a hollow portion formed from the slurry supply hole toward the upper surface; The second flow path includes a hollow portion formed in two lateral directions around one end of the first flow path.

2. The slurry circulation system for electrode coating according to claim 1, wherein the slurry circulation system for electrode coating is a system in which the slurry is circulated through the circulation pipe connected from the rear surface of the coating mold to the storage tank when the production line stops.

3. The slurry circulation system for electrode coating according to claim 1, wherein the slurry circulation system for electrode coating is a system in which the slurry is circulated through each circulation pipe connected to the storage tank from the left and right surfaces of the coating mold when the production line stops.

4. The slurry circulation system for electrode coating according to claim 1, wherein the connection hole for connecting the circulation pipe is located on at least one of the left surface, the right surface, the rear surface, and the lower surface of the coating mold, and When the production line stops, the electrode active material slurry supplied through the slurry supply hole moves through the slurry movement path in both lateral directions within the coating mold and circulates to the storage tank through the circulation pipe connected to the connection hole.

5. The slurry circulation system for electrode coating according to claim 1, wherein the slurry circulation system for electrode coating further comprises: A pump for supplying the slurry from the storage tank to the coating die; Filter; and a valve connected to the slurry supply port.

6. The slurry circulation system for electrode coating according to claim 5, wherein the slurry circulation system for electrode coating further comprises: Reflux valve; The system includes a drain pipe connecting the reflux valve and the storage tank; and when the production line stops, the reflux valve is opened so that a portion of the electrode active material slurry supplied from the storage tank is discharged into the storage tank through the drain pipe.

7. The slurry circulation system for electrode coating according to claim 1, wherein the coating mold is provided with a discharge section to which the electrode coating slurry is discharged.

8. The slurry circulation system for electrode coating according to claim 7, wherein the coating mold is provided with a lip guard that can block and open the discharge section.

9. A slurry circulation method for electrode coating, the method using a slurry circulation system as described in any one of claims 1 to 8.

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