A coating die with multi-stage flow equalization device

Abstract

The application relates to a coating die head with a multi-stage current equalizing device and relates to the technical field of electrode tabs. The coating die head comprises a base, the surface of the base is provided with a lower die, the upper side of the lower die is provided with an upper die, the upper die and the lower die are mutually spliced and form a die lip slit, the upper side of the upper die is provided with a top die, the top of the top die is provided with a feeding port, the coating die head further comprises a main current equalizing unit and a plurality of secondary current equalizing units; the current equalizing unit and the secondary current equalizing unit each comprise a main body block, a main flow channel is formed in the main body block, the main flow channel of the main current equalizing unit is communicated with the feeding port, a plurality of shunt channels are further formed in the main body block, a plurality of shunt channels are formed in the upper die and are used for communicating the shunt channels of the main current equalizing unit and the secondary current equalizing unit; a discharging collection cavity is further formed in the main body block, and the discharging collection cavity is communicated with the outlet sections of all the shunt channels. The application has the effects of effectively saving the consistency of slurry and improving the uniformity and adaptability of a coating.

Description

Technical Field

[0001] This application relates to the field of electrode technology, and in particular to a coating die head with a multi-stage flow equalization device. Background Technology

[0002] The coating die is the core component of a slot extrusion coating system, also known as the "heart" of the coating equipment. It directly determines the thickness, uniformity, and final coating quality of the coating and is widely used in high-end precision manufacturing fields such as new energy and optical thin films. Currently, existing technologies typically employ a single-stage "coat hanger" flow channel or a simple T-shaped cavity design. These designs are effective for low-viscosity, Newtonian fluid slurries, but with the development of battery technology, slurries exhibit characteristics such as high solid content, high viscosity, and non-Newtonian fluid (shear-thinning). The traditional single-stage flow channel design has revealed obvious defects and therefore needs improvement. Summary of the Invention

[0003] In order to effectively maintain the consistency of the slurry and improve the uniformity and adaptability of the coating, this application provides a coating die head with a multi-stage flow equalization device.

[0004] The coating die head with a multi-stage flow equalization device provided in this application adopts the following technical solution: A coating die head with a multi-stage flow equalization device includes a base, a lower die on the surface of the base, an upper die above the lower die, the upper and lower dies being joined together to form a die lip slit, a top die above the upper die, and a feed inlet at the top of the top die. It also includes a main flow equalization unit and several secondary flow equalization units, both positioned between the feed inlet and the die lip slit. Each flow equalization unit and secondary flow equalization unit includes a main block, with a main flow channel inside the main block. The main flow channel of the main flow equalization unit is connected to the feed inlet. Several branch flow channels are also provided within the main block, arranged along the length of the main flow channel and distributed on both sides of the main flow channel, communicating with it. Several flow equalization channels for connecting the branch flow channels of the main and secondary flow equalization units are provided within the upper die. A discharge collection cavity is also provided within the main block, communicating with the outlet sections of all branch flow channels to guide the fluid to the die lip slit.

[0005] Preferably, the inner diameter of the plurality of diversion channels exhibits a trend of gradually narrowing at the inlet, remaining constant in the middle, and gradually expanding at the outlet along the fluid flow direction.

[0006] Preferably, the cone angle α of the contraction section of the diversion channel ranges from 5° to 30°, and the cone angle β of the expansion section of the diversion channel ranges from 5° to 45°.

[0007] Preferably, the length direction of the main body block is parallel to the length direction of the die lip slit, and the main channel is arranged through the main body block along its longitudinal direction.

[0008] Preferably, the outlets of the plurality of diversion channels are arranged in the same direction, and the sum of the cross-sectional areas of the outlets of all the diversion channels is greater than the cross-sectional area of ​​the main channel.

[0009] Preferably, the spacing of the diversion channels gradually decreases from the center to both ends along the length of the main block, so that the spacing of the diversion channels at the far end is denser, thereby compensating for the pressure loss of the fluid flowing along the main channel.

[0010] Preferably, the main body block has at least one flexible rectifier grid layer on the side facing the flow equalization channel. The flexible rectifier grid layer has a plurality of micropores arranged in an array to perform secondary homogenization on the fluid after it passes through the discharge collection cavity.

[0011] Preferably, the flexible rectifier grid layer is made of a polymer material resistant to solvent corrosion, and the micropores are circular or regular hexagonal with an equivalent of 0.5mm-3mm and an opening rate of 60%-85%.

[0012] Preferably, both ends of the main body block are provided with seals to isolate bypass leakage between the main channel and the discharge collection chamber.

[0013] Preferably, a slurry buffer space is provided inside the lower mold, and the slurry buffer space is connected to the discharge collection cavity of the flow equalization unit and the mold lip slit.

[0014] In summary, this application includes at least one of the following beneficial technical effects: 1. This application can fundamentally eliminate edge effects and flow lines through multi-level synergistic effects, significantly improve the areal density uniformity of battery electrodes, thereby improving the energy density and cycle life of the battery; 2. This application is applicable to advanced battery slurries with high viscosity, high solid content, and easy sedimentation (such as silicon-carbon anode slurry), solving the problem that traditional die heads cannot handle; 3. This application can effectively reduce defects, improve yield, effectively reduce scrap caused by uneven coating, and reduce production costs. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a coating die head with a multi-stage flow equalization device according to an embodiment of this application.

[0016] Figure 2 This is a first-view cross-sectional view of the coating die head according to an embodiment of this application.

[0017] Figure 3This is a second-view cross-sectional view of the coating die head according to an embodiment of this application.

[0018] Explanation of reference numerals in the attached drawings: 1. Base; 2. Lower mold; 21. Slurry buffer space; 3. Upper mold; 31. Flow equalization channel; 4. Mold lip slit; 5. Top mold; 51. Inlet; 6a. Main flow equalization unit; 6b. Secondary flow equalization unit; 61. Main block; 62. Main flow channel; 63. Flow dividing channel; 64. Discharge collection cavity; 65. Flexible rectifier grid layer; 66. Micropores; 67. Seal. Detailed Implementation

[0019] The following is in conjunction with the appendix Figure 1-3 This application will be described in further detail.

[0020] This application discloses a coating die head with a multi-stage flow equalization device. (Refer to...) Figure 1 , Figure 2 and Figure 3 The system includes a base 1, a lower mold 2 connected to the surface of the base 1 by bolts, an upper mold 3 above the lower mold 2, the upper mold 3 and the lower mold 2 are spliced ​​together by bolts to form a mold lip slit 4, a top mold 5 above the upper mold 3, the upper mold 3 and the top mold 5 are connected by bolts, and a feed port 51 is provided on the top of the top mold 5.

[0021] Reference Figure 1 , Figure 2 and Figure 3 The coating die head also includes a main flow equalization unit 6a and several secondary flow equalization units 6b, wherein the number of secondary flow equalization units 6b is at least two. In this embodiment, the description is based on the number of two secondary flow equalization units 6b. The two secondary flow equalization units 6b are respectively arranged on both sides of the main flow equalization unit 6a. Both the main flow equalization unit 6a and the secondary flow equalization units 6b are arranged between the feed port 51 and the die lip slit 4.

[0022] Reference Figure 1 , Figure 2 and Figure 3Both the flow equalization unit and the secondary flow equalization unit 6b include a main body block 61. The length direction of the main body block 61 is parallel to the length direction of the die lip slit 4. The main flow channel 62 runs through the main body block 61 along its longitudinal direction. The main flow channel 62 is located inside the main body block 61. The main flow channel 62 of the main flow equalization unit 6a is connected to the feed inlet 51. The main body block 61 also has several branch channels 63. These branch channels 63 are arranged along the length direction of the main flow channel 62, distributed on both sides of the main flow channel 62 and connected to it. The outlets of the branch channels 63 face the same direction, and the sum of the cross-sectional areas of the outlets of all branch channels 63 is greater than that of the main flow channel 62. 2. Cross-sectional area; In this embodiment, the inner diameter of several diversion channels 63 gradually contracts at the inlet, remains constant in the middle, and gradually expands at the outlet along the fluid flow direction. The cone angle α of the contraction section of the diversion channel 63 ranges from 5° to 30°, and the cone angle β of the expansion section of the diversion channel 63 ranges from 5° to 45°. Several flow equalization channels 31 are provided in the upper mold 3 to connect the main flow equalization unit 6a and the secondary flow equalization unit 6b. The spacing of the diversion channels 63 gradually decreases from the center to both ends along the length direction of the main block 61, so that the spacing of the diversion channels 63 at the far end is denser, thereby compensating for the pressure loss of the fluid flowing along the main flow channel 62.

[0023] Reference Figure 1 , Figure 2 and Figure 3 The main body block 61 has at least one flexible rectifier grid layer 65 on the side facing the flow equalization channel 31. The flexible rectifier grid layer 65 has a plurality of micropores 66 arranged in an array to perform secondary homogenization of the fluid after passing through the discharge collection chamber 64. In this embodiment, the flexible rectifier grid layer 65 is made of a polymer material resistant to solvent corrosion. The micropores 66 are circular or regular hexagonal, with an equivalent of 0.5mm-3mm and an opening rate of 60%-85%.

[0024] Reference Figure 1 , Figure 2 and Figure 3 Both ends of the main block 61 are provided with seals 67 to isolate the bypass leakage between the main channel 62 and the discharge collection chamber 64.

[0025] Reference Figure 1 , Figure 2 and Figure 3 The main block 61 is also provided with a discharge collection cavity 64, which is connected to the outlet section of all the diversion channels 63 to guide the fluid to the die lip slit 4; the lower die 2 is provided with a slurry buffer space 21, which is connected to the discharge collection cavity 64 of the flow equalization unit and the die lip slit 4.

[0026] The implementation principle of a coating die head with a multi-stage flow equalization device in this application embodiment is as follows: Based on the original coating die head, a main flow equalization unit 6a and a secondary flow equalization unit 6b are set between the feed inlet 51 and the die lip slit 4. These units are composed of at least two flow equalization units with different functions connected in series to gradually equalize the slurry. A slurry buffer space 21 is set inside the lower die 2 to increase the amount of slurry flowing within the die lip slit 4, thereby effectively preserving the consistency of the slurry and improving the uniformity and adaptability of the coating.

[0027] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A coating die head with a multi-stage flow equalization device, comprising a base, a lower die disposed on the surface of the base, an upper die disposed above the lower die, the upper die and the lower die being joined together to form a die lip slit, a top die disposed above the upper die, and a feed inlet disposed at the top of the top die, characterized in that: It also includes a main flow equalization unit and several secondary flow equalization units, both of which are located between the feed inlet and the die lip slit. Each flow equalization unit and secondary flow equalization unit includes a main body block, inside which a main flow channel is formed. The main flow channel of the main flow equalization unit is connected to the feed inlet. Several branch flow channels are also formed inside the main body block, arranged along the length of the main flow channel and distributed on both sides of the main flow channel and connected to it. Several flow equalization channels for connecting the branch flow channels of the main flow equalization unit and the secondary flow equalization unit are formed inside the upper die. A discharge collection cavity is also formed inside the main body block, which is connected to the outlet section of all branch flow channels to guide the fluid to the die lip slit.

2. The coating die head with a multi-stage flow equalization device according to claim 1, characterized in that: The inner diameter of several of the diversion channels tends to gradually shrink at the inlet section, remain constant in the middle section, and gradually expand at the outlet section along the fluid flow direction.

3. A coating die head with a multi-stage flow equalization device according to claim 2, characterized in that: The cone angle α of the contraction section of the diversion channel ranges from 5° to 30°, and the cone angle β of the expansion section of the diversion channel ranges from 5° to 45°.

4. A coating die head with a multi-stage flow equalization device according to claim 1, characterized in that: The length direction of the main body block is parallel to the length direction of the die lip slit, and the main channel runs through the main body block along its longitudinal direction.

5. A coating die head with a multi-stage flow equalization device according to claim 4, characterized in that: The outlets of several of the diversion channels are arranged in the same direction, and the sum of the cross-sectional areas of the outlets of all the diversion channels is greater than the cross-sectional area of ​​the main channel.

6. A coating die head with a multi-stage flow equalization device according to claim 4, characterized in that: The spacing of the diversion channels gradually decreases from the center to both ends along the length of the main block, so that the spacing of the diversion channels at the far end is denser, thereby compensating for the pressure loss of the fluid flowing along the main channel.

7. A coating die head with a multi-stage flow equalization device according to claim 1, characterized in that: The main body block has at least one flexible rectifier grid layer on the side facing the flow equalization channel. The flexible rectifier grid layer has several micro-holes arranged in an array to perform secondary homogenization on the fluid after it passes through the discharge collection chamber.

8. A coating die head with a multi-stage flow equalization device according to claim 7, characterized in that: The flexible rectifier grid layer is made of a polymer material resistant to solvent corrosion. The micropores are circular or regular hexagonal, with an equivalent of 0.5mm-3mm and an opening rate of 60%-85%.

9. A coating die head with a multi-stage flow equalization device according to claim 1, characterized in that: Both ends of the main block are equipped with seals to prevent bypass leakage between the main channel and the discharge collection chamber.

10. A coating die head with a multi-stage flow equalization device according to claim 1, characterized in that: The lower mold has a slurry buffer space, which is connected to the discharge collection cavity of the flow equalization unit and the mold lip slit.

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