Coating die head and coating method

Abstract

The invention discloses a coating die head. The coating die head comprises a first die head, a second die head and a third die head which are arranged in sequence. A first flow channel allowing glue to flow is formed between the first die head and the second die head, a second flow channel allowing glue to flow is formed between the second die head and the third die head, and the first flow channel and the second flow channel intersect and communicate with the same discharge port. A first cavity communicating with the first runner is formed in the first die head or the second die head, and a second cavity communicating with the second runner is formed in the second die head or the third die head. The first cavity is connected with a first servo valve used for controlling on-off of glue liquid, and the second cavity is connected with a second servo valve used for controlling on-off of slurry. According to the coating die head, the two runners are formed through the three die heads, the slurry and the glue solution in the two runners are controlled to be coated respectively through the two servo valves, interval coating and slurry edge gluing are both considered, and the control precision and the production takt are improved.

Description

Technical Field

[0001] This invention belongs to the field of coating equipment, and particularly relates to a coating die head for intermittent coating and a coating method. Background Technology

[0002] In the field of lithium-ion battery manufacturing, intermittent coating processes are commonly used to achieve reliable tab welding. This involves applying a slurry (such as the positive or negative electrode active material) intermittently onto a metal foil (current collector), leaving clean, uncoated areas as welding stations. Simultaneously, to further enhance battery safety and electrochemical performance, advanced processes may overlay a layer of functional adhesive (such as a coating containing ceramic particles) at the edges of the coated slurry. This adhesive layer significantly enhances the foil's puncture resistance, preventing internal short circuits; furthermore, its porous structure facilitates electrolyte wetting and retention, thereby reducing interfacial impedance and improving conductivity.

[0003] However, existing technologies typically face the dual challenges of controlling precision and process stability in order to achieve the aforementioned composite structure of "slurry intermittent coating" and "edge coating". Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention provides a coating die and coating method that combines interval coating and edge coating.

[0005] To achieve the above objectives, the coating die head of the present invention includes: a first die head, a second die head, and a third die head arranged sequentially; a first flow channel for the flow of adhesive liquid is formed between the first die head and the second die head, and a second flow channel for the flow of slurry is formed between the second die head and the third die head; the first flow channel and the second flow channel intersect and are connected to the same outlet; a first cavity communicating with the first flow channel is provided inside the first die head or the second die head, and a second cavity communicating with the second flow channel is provided inside the second die head or the third die head; a first servo valve for controlling the flow of adhesive liquid is connected to the first cavity, and a second servo valve for controlling the flow of slurry is connected to the second cavity.

[0006] In one embodiment of the coating die head of the present invention, both the first servo valve and the second servo valve are electro-hydraulic servo valves.

[0007] In one embodiment of the coating die head of the present invention, a first adjustment component for adjusting the size of the first flow channel is provided between the first die head and the second die head.

[0008] In one embodiment of the coating die head of the present invention, a plurality of first adjustment components are provided and are arranged at equal intervals along the extension direction of the first die head; each of the first adjustment components includes a first adjustment body and a first adjustment screw, the first adjustment body is mounted on the upper surface of the first die head, and the first adjustment screw passes through the first die head.

[0009] In one embodiment of the coating die head of the present invention, the third die head is provided with a second adjustment component for adjusting the size of the second flow channel.

[0010] In one embodiment of the coating die head of the present invention, a through groove is provided on the lower surface of the third die head near the discharge port, the through groove dividing the third die head into a main body and an adjustment part that are connected to each other; multiple second adjustment components are provided and are arranged at equal intervals along the extension direction of the third die head; each second adjustment component includes a second adjustment main body and a second adjustment screw, the second adjustment main body is installed on the main body, and the second adjustment screw passes through the main body and is connected to the adjustment part.

[0011] In one embodiment of the coating die head of the present invention, the longitudinal section of the second die head is triangular, the first die head is attached to the upper surface of the second die head, and the third die head is attached to the lower surface of the second die head.

[0012] In one embodiment of the coating die head of the present invention, the longitudinal section of the second die head is a right-angled triangle; the first flow channel is inclined relative to the horizontal plane, and the second flow channel is parallel to the horizontal plane.

[0013] In one embodiment of the coating die head of the present invention, the first cavity is disposed in the second die head, and the second cavity is disposed in the third die head.

[0014] The present invention also discloses a coating method, comprising the following steps: S1: The foil is conveyed by the coating roller so that the traveling surface of the foil comes into contact with the outlet of the coating die head; S2: Open the first servo valve and close the second servo valve to coat the foil surface with adhesive from the outlet, forming the first adhesive segment; S3: Close the first servo valve and open the second servo valve, so that the slurry is coated from the outlet onto the foil surface downstream of the first adhesive section to form a slurry section; S4: Close the second servo valve and open the first servo valve again, so that the adhesive is coated from the outlet onto the foil surface of the slurry section away from the first adhesive section to form the second adhesive section; S5: Close the first servo valve to complete the coating of a "liquid-slurry-liquid" combined structure; Repeat steps S2 to S5 to form a plurality of spaced-apart composite structures on the foil.

[0015] In summary, the coating die head of the present invention forms two flow channels through three dies, and the slurry and adhesive in the two flow channels are coated separately by two servo valves, taking into account both intermittent coating and edge coating of slurry, thereby improving control accuracy and production cycle. Attached Figure Description

[0016] Figure 1 This is the intermittent composite coating structure applied in the embodiments of the present invention;

[0017] Figure 2 This is a cross-sectional view of the coating die head according to an embodiment of the present invention;

[0018] In the diagram: 100, coating roller; 200, foil; 210, first adhesive section; 220, slurry section; 230, second adhesive section; 1, first die head; 11, first protrusion; 2, second die head; 21, first cavity; 22, first feed inlet; 3, third die head; 31, third protrusion; 32, through groove; 33, main body; 34, adjusting part; 35, second cavity; 36, second feed inlet; 4, first flow channel; 5, second flow channel; 6, discharge port; 7, first adjusting assembly; 71, first adjusting main body; 72, first adjusting screw; 8, second adjusting assembly; 81, second adjusting main body; 82, second adjusting screw; 9, first servo valve; 10, second servo valve. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0020] This invention provides a coating die and coating method, particularly suitable for the precise and efficient preparation of an intermittent composite coating structure of "solvent-slurry-solvent" on metal foil in the manufacture of lithium-ion battery electrodes. Figure 1 As shown. The core of this solution lies in the use of a unique three-layer mold head integrated design, combined with a high-precision servo valve control system, to achieve sequential coating and integrated molding of two different materials (such as electrode slurry and ceramic adhesive) in a wet state. This effectively solves the technical bottlenecks of traditional step-by-step coating processes, such as weak interface bonding, poor boundary alignment accuracy, and low production efficiency.

[0021] like Figure 2The diagram shows a cross-sectional view of the coating die head, facilitating understanding of the flow path of the slurry and adhesive inside the coating die head. The coating roller 100 is used to transfer the slurry. The axial direction of the coating roller 100 is perpendicular to the paper surface. In this embodiment, the coating die head extends in a direction perpendicular to the paper surface and is arranged parallel to the coating roller 100, and contacts the foil 200 to coat the foil 200.

[0022] The coating die head mainly includes components along the vertical direction (with...) Figure 2 Based on the first mold head 1, the second mold head 2 and the third mold head 3 are set sequentially.

[0023] The longitudinal section of the second die head 2 is preferably a right-angled triangle. The first die head 1 is attached and fixed to the upper surface of the hypotenuse of the second die head 2, forming a first flow channel 4 for the flow of adhesive liquid. The third die head 3 is attached and fixed to the lower surface of the right-angled side of the second die head 2, forming a second flow channel 5 for the flow of slurry. The first flow channel 4 and the second flow channel 5 converge at the front end of the die head and are connected to a unified discharge port 6. This design ensures that the two materials only converge at the moment they leave the die head, minimizing mutual interference and ensuring the adhesion of the slurry and adhesive liquid on the foil 200.

[0024] The first die head 1 has a first protrusion 11 protruding outward at one end near the discharge port 6. The third die head 3 has a third protrusion 31 protruding outward at one end near the discharge port 6. The first protrusion 11 and the third protrusion 31 are precisely fitted together with the right end face of the second die head 2 to form the discharge port 6, which is used to control the coating thickness.

[0025] To achieve adjustable adhesive coating thickness, a first adjustment component 7 is provided between the first die head 1 and the second die head 2. Multiple first adjustment components 7 are provided, arranged along the width direction of the die head (i.e., ...). Figure 2 The components are arranged at equal intervals (perpendicular to the paper surface). Each first adjustment component 7 includes a first adjustment body 71 mounted on the upper surface of the first die head 1, and a first adjustment screw 72 passing through the first die head 1 and having its end capable of abutting or finely adjusting the position of the second die head 2. By turning each first adjustment body 71 to rotate the first adjustment screw 72, the gap size of the first flow channel 4 can be locally and precisely adjusted, thereby compensating for machining or installation errors and ensuring the consistency of the adhesive coating thickness across the entire width. The first adjustment component 7 is preferably a micrometer.

[0026] To achieve lateral uniformity in the slurry coating thickness, a second adjustment assembly 8 is provided inside the third die head 3. Specifically, a through groove 32 is machined on the lower surface of the third die head 3, near the discharge port 6. This through groove 32 divides the front end of the third die head 3 into an interconnected main body 33 and an adjustment part 34 capable of slight elastic deformation. Multiple second adjustment assemblies 8 are also provided and arranged at equal intervals. Each second adjustment assembly 8 includes a second adjustment main body 81 mounted on the main body 33, and a second adjustment screw 82 that passes through the main body 33 and is threadedly connected to the adjustment part 34. By screwing each second adjustment main body 81, the adjustment part 34 can be driven to produce a slight bending deformation, thereby locally changing the gap at the end of the second flow channel 5 and achieving high-precision fine-tuning of the slurry coating thickness.

[0027] In this embodiment, the first cavity 21 is directly disposed inside the second die head 2, and a first feed port 22 is formed on the left surface of the second die head 2 and connected to the feed end of the first flow channel 4, for containing and distributing adhesive liquid. The second cavity 35 is directly disposed inside the third die head 3, and a second feed port 36 is formed on the left surface of the third die head 3 and connected to the feed end of the second flow channel 5, for containing and distributing slurry.

[0028] The first feed port 22 is connected to the first servo valve 9 via a pipeline, and the second feed port 36 is connected to the second servo valve 10 via a pipeline, with the feed supplied by an external slurry and adhesive supply pump. The first servo valve 9 and the second servo valve 10 are preferably electro-hydraulic servo valves, controlling the inflow and outflow of slurry and adhesive through electro-mechanical conversion and hydraulic amplification. Both the first servo valve 9 and the second servo valve 10 are electrically connected to a central controller, capable of receiving commands for independent and precise opening and closing at the millisecond level.

[0029] In other embodiments, the first cavity 21 may also be disposed in the first mold head 1, and the second cavity 35 may also be disposed in the second mold head 2.

[0030] Another embodiment of the present invention discloses a coating method, comprising: S1: Start the coating equipment. The coating roller 100 transfers the slurry at a constant speed. Adjust the position of the coating die head so that its outlet 6 maintains a preset gap or slight contact with the surface of the foil 200.

[0031] S2: Applying the first layer of adhesive: The controller issues a command to open the first servo valve 9 while keeping the second servo valve 10 closed. Under pressure, the adhesive flows out from the outlet 6 through the first chamber 21 and the first flow channel 4, and is precisely coated on the surface of the moving foil 200, forming a first adhesive segment 210 of a preset length.

[0032] S3: When the first adhesive segment 210 reaches the predetermined length, the controller immediately closes the first servo valve 9 and simultaneously opens the second servo valve 10. The slurry then flows out from the outlet 6 through the second cavity 35 and the second flow channel 5, and begins to coat the end of the first adhesive segment 210, forming a slurry segment 220 on the foil 200.

[0033] S4: When the slurry section 220 reaches the predetermined length, the controller closes the second servo valve 10 and reopens the first servo valve 9. The adhesive is coated again, forming the second adhesive section 230 immediately adjacent to the end of the slurry section 220.

[0034] S5: When the second adhesive section 230 reaches the predetermined length, the controller immediately closes the first servo valve 9, thereby completing a complete "adhesive-slurry-adhesive" combination structure.

[0035] Repeat steps S2 to S5 to form a series of spaced composite structures on foil 200. Subsequently, the foil carrying this wet composite coating enters a drying system for integrated drying and curing, forming a firmly bonded solid composite electrode.

[0036] Since the coating roller 100 transfers the slurry at a constant speed, the lengths of the first adhesive section 210, the slurry section 220, and the second adhesive section 230 can be controlled by controlling the opening and closing times of the first servo valve 9 and the second servo valve 10.

[0037] The above description is only a part or preferred embodiment of this application. Neither the text nor the drawings should limit the scope of protection of this application. All equivalent structural transformations made using the content of this application's specification and drawings under the overall concept of this application, or direct / indirect applications in other related technical fields, are included within the scope of protection of this application.

Claims

1. A coating die head, characterized in that, include: A first mold head, a second mold head, and a third mold head are arranged sequentially. A first flow channel for the flow of adhesive liquid is formed between the first mold head and the second mold head, and a second flow channel for the flow of slurry is formed between the second mold head and the third mold head. The first flow channel and the second flow channel intersect and are connected to the same outlet. A first cavity connected to the first flow channel is provided inside the first mold head or the second mold head, and a second cavity connected to the second flow channel is provided inside the second mold head or the third mold head. A first servo valve for controlling the flow of adhesive liquid is connected to the first cavity, and a second servo valve for controlling the flow of slurry is connected to the second cavity.

2. The coating die head as described in claim 1, characterized in that, Both the first servo valve and the second servo valve are electro-hydraulic servo valves.

3. The coating die head as described in claim 1, characterized in that, A first adjustment component for adjusting the size of the first flow channel is provided between the first mold head and the second mold head.

4. The coating die head as described in claim 3, characterized in that, Multiple first adjustment components are provided and are arranged at equal intervals along the extension direction of the first mold head; each first adjustment component includes a first adjustment body and a first adjustment screw, the first adjustment body is mounted on the upper surface of the first mold head, and the first adjustment screw passes through the first mold head.

5. The coating die head as described in claim 1, characterized in that, The third mold head is provided with a second adjustment component for adjusting the size of the second flow channel.

6. The coating die head as described in claim 5, characterized in that, A through groove is provided on the lower surface of the third die head near the discharge port, which divides the third die head into a main body and an adjustment part that are connected to each other; multiple second adjustment components are provided and are arranged at equal intervals along the extension direction of the third die head; each second adjustment component includes a second adjustment main body and a second adjustment screw, the second adjustment main body is installed on the main body, and the second adjustment screw passes through the main body and is connected to the adjustment part.

7. The coating die head as described in claim 1, characterized in that, The second mold head has a triangular longitudinal section, the first mold head is attached to the upper surface of the second mold head, and the third mold head is attached to the lower surface of the second mold head.

8. The coating die head as described in claim 7, characterized in that, The longitudinal section of the second mold head is a right-angled triangle; the first flow channel is inclined relative to the horizontal plane, and the second flow channel is parallel to the horizontal plane.

9. The coating die head as described in claim 1, characterized in that, The first cavity is disposed in the second mold head, and the second cavity is disposed in the third mold head.

10. A coating method, applied to a coating die as described in any one of claims 1 to 9, characterized in that, Includes the following steps: S1: The foil is conveyed by the coating roller so that the traveling surface of the foil comes into contact with the outlet of the coating die head; S2: Open the first servo valve and close the second servo valve to coat the foil surface with adhesive from the outlet, forming the first adhesive segment; S3: Close the first servo valve and open the second servo valve, so that the slurry is coated from the outlet onto the foil surface downstream of the first adhesive section to form a slurry section; S4: Close the second servo valve and open the first servo valve again, so that the adhesive is coated from the outlet onto the foil surface of the slurry section away from the first adhesive section to form the second adhesive section; S5: Close the first servo valve to complete the coating of a "liquid-slurry-liquid" combined structure; Repeat steps S2 to S5 to form a plurality of spaced-apart composite structures on the foil.

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