Coating die head, and coating apparatus for electrode sheets

Abstract

A coating die head, and a coating apparatus for an electrode sheet. The coating die head is provided with a feed inlet (111), a first flow equalizing cavity (11210), flow channels (11220), and a plurality of coating ports (1410); the first flow equalizing cavity (11210) extends in a first direction and is communicated with the feed inlet (111); the plurality of coating ports (1410) are arranged at intervals in the first direction; and the flow channels (11220) are used for communicating the first flow equalizing cavity (11210) with the plurality of coating ports (1410). In the direction of the coating ports (1410) moving away from the feed inlet (111), the minimum lengths of the flow channels (11220) between the coating ports (1410) among the plurality of coating ports (1410) and the first flow equalizing cavity (11210) show a decreasing trend.

Description

Coating die and electrode coating device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202321618854.7, filed on June 25, 2023, entitled “Coating die head and coating device for pole piece”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the technical field of battery production, and in particular to a coating die head and a coating device for a pole piece. Background Art

[0004] Batteries have the advantages of high specific energy and high power density, and are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric airplanes, electric boats, electric toy cars, electric toy boats, electric toy airplanes and power tools, etc.

[0005] As an important process in the battery production process, the coating process has a very important impact on the quality of the battery. How to improve the uniformity of the slurry coating in the coating process has always been an important research direction for those skilled in the art.

[0006] Summary of the Invention

[0007] In view of the above problems, the present application provides a coating die and a coating device for a pole piece, wherein the coating die can improve the uniformity of slurry coating in the coating process.

[0008] In the first aspect, the present application provides a coating die, which includes a die body, a feed port, a first flow equalizing chamber, a flow channel and multiple coating ports, the first flow equalizing chamber extends along a first direction and is connected to the feed port, the multiple coating ports are arranged at intervals along the first direction, and the flow channel is used to connect the first flow equalizing chamber and the multiple coating ports; among the multiple coating ports, along the direction of the coating port away from the feed port, the minimum length of the flow channel between the coating port and the first flow equalizing chamber tends to decrease.

[0009] In the above structure, the pressure lost by the slurry flowing to the coating port away from the feed port during the flow process is less than the pressure lost by the slurry flowing to the coating port close to the feed port during the flow process, thereby increasing the pressure of the slurry at the coating port away from the feed port, balancing the pressure of the slurry at multiple coating ports, and is beneficial to improving the consistency of the discharge of multiple coating ports, and improving the uniformity of the slurry coating in the coating process.

[0010] According to some embodiments of the present application, the coating die head provided, the die head body includes a first die head, a second die head and a pressure strip, the first die head includes a first cavity and a feed port connected to the first cavity, the second die head is connected to the pressure strip and covers the first cavity, the pressure strip is spaced apart from at least part of the inner wall of the first cavity, and the gap between the pressure strip and the inner wall of the first cavity forms a flow channel and a first equalizing flow cavity.

[0011] According to the coating die provided in some embodiments of the present application, the layering strip includes a first side surface, a second side surface, and a third side surface, the second side surface and the third side surface are arranged relative to each other in a second direction, the first side surface is connected between the second side surface and the third side surface, the third side surface is attached to the inner wall surface of the first cavity, a flow channel is formed between the first side surface and the inner wall surface of the first cavity, a first flow balancing cavity is formed between the second side surface and the inner wall surface of the first cavity, and the second direction is perpendicular to the first direction. By forming a flow channel between the first side surface and the inner wall surface of the first cavity, a first flow balancing cavity is formed between the second side surface and the inner wall surface of the first cavity, so that the flow channel and the first flow balancing cavity are smoothly connected.

[0012] According to the coating die provided in some embodiments of the present application, the die body also includes a gasket, which is provided with a plurality of notches spaced apart along a first direction. The gasket is clamped between the first die and the second die. The plurality of notches are all connected to the flow channel to form a coating port, so that the coating port is connected to the first flow equalization cavity through the flow channel.

[0013] According to the coating die provided in some embodiments of the present application, the first die is provided with a second cavity, the second die covers the second cavity to form a second flow equalization cavity, the second flow equalization cavity is connected to a plurality of coating ports, and the second cavity can temporarily store the slurry flowing to the coating port, which is conducive to making the output of the slurry more uniform and stable.

[0014] According to some embodiments of the present application, the coating die head further includes a first adjusting rod and a second adjusting rod, the first adjusting rod is connected to the first die head, and the second adjusting rod is connected to the second die head, and the first adjusting rod and the second adjusting rod are used to adjust the opening size of the coating port so that the coating die head can adjust the coating weight of the slurry.

[0015] According to the coating die provided in some embodiments of the present application, the first cavity and the pressure strip both extend along the first direction, and the distance between the second side and the third side continuously decreases along the direction in which the coating port is away from the feed port in the first direction, so that along the direction in which the coating port is away from the feed port in the first direction, the shortest part of the flow channel used to connect the coating port and the first flow equalizing cavity continuously shortens, so that the minimum length of the flow channel between the coating port close to the feed port and the first flow equalizing cavity is greater than the minimum length of the flow channel between the coating port away from the feed port and the first flow equalizing cavity.

[0016] According to the coating die provided in some embodiments of the present application, the first side surface is configured as a circular arc surface, so that the slurry flows smoothly in the flow channel, which is beneficial to reducing the resistance during the flow of the slurry.

[0017] According to the coating die provided in some embodiments of the present application, the die body also includes a connecting piece, a through hole is provided on the gasket, and the connecting piece passes through the pressure strip and the through hole and is connected to the second die to fix the pressure strip to the second die, so that the pressure strip can be detachably connected to the second die.

[0018] According to the coating die head provided in some embodiments of the present application, there are multiple first adjustment rods, and the multiple first adjustment rods are arranged at intervals along the first direction; there are multiple second adjustment rods, and the multiple second adjustment rods are arranged at intervals along the first direction, so that the operator can individually adjust the openings of multiple coating ports arranged at intervals along the first direction through multiple first adjustment rods or multiple second adjustment rods, so that the weight of the slurry coated at the coating port can be flexibly adjusted.

[0019] In a second aspect, some embodiments of the present application further provide a coating device for a pole piece, which comprises a coating die provided by any of the above technical solutions, and the coating die is used to coat slurry onto the surface of the pole piece.

[0020] The technical solutions provided by the embodiments of the present disclosure bring at least the following beneficial effects:

[0021] The present application provides a coating die head, which is provided with a feed port, a first flow balancing chamber, a flow channel and a plurality of coating ports, wherein the first flow balancing chamber extends along a first direction and is connected to the feed port, the plurality of coating ports are spaced apart along the first direction, and the flow channel is used to connect the first flow balancing chamber and the plurality of coating ports. Since the minimum length of the flow channel between the coating port and the first flow balancing chamber in the plurality of coating ports tends to decrease along the direction in which the coating port is away from the feed port, the pressure lost by the slurry flowing to the coating port away from the feed port during the flow process is less than the pressure lost by the slurry flowing to the coating port close to the feed port during the flow process, thereby increasing the pressure of the slurry at the coating port away from the feed port, balancing the pressure of the slurry at the plurality of coating ports, and facilitating the improvement of the consistency of the discharge of the plurality of coating ports, and improving the uniformity of the slurry coating in the coating process.

[0022] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0024] FIG1 is a perspective view of a coating die provided in some embodiments of the present application;

[0025] FIG2 is a schematic structural diagram of a coating die provided in some embodiments of the present application at a viewing angle;

[0026] FIG3 is a schematic structural diagram of a coating die provided in some embodiments of the present application from another perspective;

[0027] FIG4 is a cross-sectional view of point A in FIG1 ;

[0028] FIG5 is a cross-sectional view of point B in FIG1;

[0029] FIG6 is a cross-sectional view of a first die head and a bead provided in some embodiments of the present application;

[0030] FIG7 is a schematic structural diagram of a first die head and a pressure strip provided in some embodiments of the present application;

[0031] FIG8 is a schematic diagram of the structure of a first die head provided in some embodiments of the present application;

[0032] FIG9 is a schematic diagram of a partial structure of a die body provided in some embodiments of the present application;

[0033] FIG10 is an enlarged view of point C in FIG3 .

[0034] The accompanying drawings in the specific implementation manner are as follows:

[0035] 1. Die body; 11. First die; 111. Feed port; 112. First cavity; 1121. Inner wall; 11210. First flow-distributing cavity; 11220. Flow channel; 113. Second cavity; 11310. Second flow-distributing cavity; 12. Second die; 13. Pressing strip; 131. First side surface; 132. Second side surface; 133. Third side surface; 14. Gasket; 141. Notch; 142. Through hole; 1410. Coating port; 15. Connector; 2. First adjusting rod; 3. Second adjusting rod; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0036] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0037] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0038] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present application.

[0039] In addition, the technical terms "first," "second," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0040] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0041] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0042] Currently, judging by market developments, batteries are increasingly being used. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles like electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace.

[0043] Coating is an essential process in battery production. The coating process has a crucial impact on battery quality, directly affecting various performance indicators such as safety, capacity, and lifespan. Coating is a key process in the battery production process. Coating involves applying a polymer paste, molten polymer, or polymer melt onto paper, cloth, or plastic film to create a composite material (film). In the electrode coating process, a coating die applies a slurry to the electrode surface to achieve good electrical properties.

[0044] At present, when using a coating die to coat the electrode, in order to improve the coating efficiency, the coating die is usually provided with multiple coating ports so that coating can be performed simultaneously at multiple locations on the electrode. However, since the multiple coating ports on the coating die are at different distances from the slurry feed port, the slurry flow rate at the coating port close to the feed port is greater than the slurry flow rate at the coating port far from the feed port due to the inertia of the slurry flowing from the feed port and the pressure loss of the slurry away from the feed port. This results in different coating weights at different locations on the electrode surface, reducing the consistency of the electrode and hindering the improvement of the electrode quality.

[0045] In order to improve the uniformity of slurry coating in the coating process, an embodiment of the present application provides a coating die head, which is provided with a feed port, a first flow balancing chamber, a flow channel and a plurality of coating ports, wherein the first flow balancing chamber extends along a first direction and is connected to the feed port, and the plurality of coating ports are arranged at intervals along the first direction, and the flow channel is used to connect the first flow balancing chamber and the plurality of coating ports. By configuring the minimum length of the flow channel between the coating port close to the feed port and the first flow balancing chamber to be greater than the minimum length of the flow channel between the coating port away from the feed port and the first flow balancing chamber, the pressure lost by the slurry flowing to the coating port away from the feed port during the flow process is less than the pressure lost by the slurry flowing to the coating port close to the feed port during the flow process, thereby increasing the pressure of the slurry at the coating port away from the feed port, balancing the pressure of the slurry at the plurality of coating ports, and facilitating the improvement of the consistency of the discharge of the plurality of coating ports, and improving the uniformity of slurry coating in the coating process.

[0046] The coating die disclosed in the embodiments of the present application can be used for coating electrodes but is not limited to it. It can also be used for coating other films such as paper, cloth, plastic film, etc. to obtain composite materials (films), thereby obtaining composite materials (films) with certain properties.

[0047] The technical solutions of the coating die head and the electrode coating device provided in the specific embodiments of the present application are further described below.

[0048] Some embodiments of the present application provide a coating die, as shown in Figures 1 to 3, the coating die includes a die body 1, as shown in Figures 4 and 5, the coating die is provided with a feed port 111, a first flow equalizing chamber 11210, a flow channel 11220 and a plurality of coating ports 1410, the first flow equalizing chamber 11210 extends along a first direction X and is connected to the feed port 111, the plurality of coating ports 1410 are arranged at intervals along the first direction X, and the flow channel 11220 is used to connect the first flow equalizing chamber 11210 and the plurality of coating ports 1410; as shown in Figure 6, among the plurality of coating ports 1410, along the direction in which the coating port 1410 is away from the feed port 111, the minimum length of the flow channel 11220 between the coating port 1410 and the first flow equalizing chamber 11210 tends to decrease.

[0049] Exemplarily, the coating die can be a component of the coating device in the coating process, used to coat the slurry on the surface of the pole piece. After the slurry passes into the coating die, it is simultaneously coated on multiple places of the pole piece under the action of the coating die to achieve efficient coating on the pole piece.

[0050] The die body 1 can be the main structure in the coating die, which is used to carry and set the structure or components in the coating die. The feed port 111, the first flow cavity 11210, the flow channel 11220 and the multiple coating ports 1410 are all set on the die body 1.

[0051] The feed port 111 may be an opening structure provided on the die body 1, which is used to allow the slurry to pass into the die body 1. The first flow equalization cavity 11210 may be a cavity structure provided in the die body 1. By extending along the first direction X in the die body 1 and communicating with the feed port 111, the slurry flowing in from the feed port 111 can be distributed and temporarily stored in the die body 1 along the first direction X, facilitating subsequent flow to the multiple coating ports 1410. The coating port 1410 may be an opening structure provided on the die body 1, which is used for the slurry to flow out so that the slurry can be coated on the surface of the electrode.

[0052] Exemplarily, there are multiple coating ports 1410, which are spaced apart along the first direction X, so that the die body 1 can simultaneously coat multiple locations of the electrode in the first direction X, which is beneficial to improving the coating efficiency of the coating die.

[0053] The flow channel 11220 may be a structure provided in the die body 1 for connecting the first flow equalizing cavity 11210 and the plurality of coating ports 1410, so that the slurry in the first flow equalizing cavity 11210 can flow smoothly into the plurality of coating ports 1410. Among the plurality of coating ports 1410, along the direction in which the coating port 1410 is away from the feed port 111, the minimum length of the flow channel 11220 between the coating port 1410 and the first flow equalizing cavity 11210 tends to decrease. It may be that the minimum length of the flow channel 11220 used to connect the coating port 1410 close to the feed port 111 among the plurality of coating ports 1410 and the portion in the first flow equalizing cavity 11210 is greater than the minimum length of the flow channel 11220 used to connect the coating port 1410 away from the feed port 111 among the plurality of coating ports 1410. 410 and the minimum length of the portion in the first flow equalization cavity 11210, which makes the pressure lost during the flow of the slurry flowing to the coating port 1410 away from the feed port 111 less than the pressure lost during the flow of the slurry flowing to the coating port 1410 close to the feed port 111, thereby increasing the pressure of the slurry at the coating port 1410 away from the feed port 111, balancing the pressure of the slurry at multiple coating ports 1410, and helping to improve the consistency of the discharge of multiple coating ports 1410, and improving the uniformity of the slurry coating in the coating process.

[0054] Exemplarily, the plurality of coating ports 1410 are spaced apart in the first direction X of the die body 1, the feed port 111 is connected to the middle portion of a first flow balancing chamber 11210 extending in the die body 1 along the first direction X, and the flow channel 11220 connects the first flow balancing chamber 11210 and the plurality of coating ports 1410. As the flow channel 11220 moves away from the feed port 111, the minimum length of the flow channel 11220 between the plurality of coating ports 1410 on both sides of the feed port 111 and the first flow balancing chamber 11210 decreases continuously, so that the pressure loss caused by the slurry flowing through the flow channel 11220 can be continuously reduced.

[0055] In some embodiments, the die body 1 includes a first die 11, a second die 12 and a pressure strip 13. The first die 11 includes a first cavity 112 and a feed port 111 connected to the first cavity 112. The second die 12 is connected to the pressure strip 13 and covers the first cavity 112. The pressure strip 13 is spaced apart from at least part of the inner wall of the first cavity 112. The gap between the pressure strip 13 and the inner wall of the first cavity 112 forms a flow channel 11220 and a first equalizing flow cavity 11210.

[0056] The first die head 11, the second die head 12 and the pressure strip 13 can all be components of the die body 1. When they are connected to form the die body 1, they can also form structures such as the first flow equalization cavity 11210 and the flow channel 11220 in the die body 1. The first cavity 112 can be a groove-shaped structure opened by the first die head 11, which extends along the first direction X and is used to form the first flow equalization cavity 11210; the pressure strip 13 can be a strip-shaped component extending along the first direction X, which is connected to the first die head 11, and the second die head 12 covers the first cavity 112 and allows the pressure strip 13 to extend into the first cavity 112. As shown in Figure 7, by spacing the pressure strip 13 from at least part of the inner wall of the first cavity 112, a first flow equalization cavity 11210 and a flow channel 11220 extending along the first direction X are formed between the pressure strip 13 and the inner wall of the first cavity 112, and the first flow equalization cavity 11210 and the flow channel 11220 are connected to each other.

[0057] For example, the cross-sectional shape of the first cavity 112 perpendicular to the first direction X can be set to a semicircular shape, so that the resistance encountered by the slurry when flowing in the first cavity 112 is small, reducing the pressure loss of the slurry during flow. As shown in Figure 8, the first cavity 112 is opened on the side of the first die head 11 facing the second die head 12, the feed port 111 is also provided on the first die head 11 and communicates with the first cavity 112, the bead 13 is connected to the side of the second die head 12 facing the first die head 11, the first die head 11 and the second die head 12 are buckled, and the bead 13 connected to the second die head 12 is placed in the first cavity 112, and a flow channel 11220 and a first flow equalizing cavity 11210 are formed between the bead 13 and the inner wall surface 1121 of the first cavity 112 on the first die head 11.

[0058] In some embodiments, the pressure strip 13 includes a first side 131, a second side 132 and a third side 133, and the second side 132 and the third side 133 are arranged relative to each other in the second direction Y, the first side 131 is connected between the second side 132 and the third side 133, and the third side 133 is attached to the inner wall surface 1121 of the first cavity 112, and a flow channel 11220 is formed between the first side 131 and the inner wall surface 1121 of the first cavity 112, and a first equal flow cavity 11210 is formed between the second side 132 and the inner wall surface 1121 of the first cavity 112, and the second direction Y is perpendicular to the first direction X.

[0059] The first side surface 131, the second side surface 132, and the third side surface 133 may be different surfaces on the upper outer side of the bead 13. The first side surface 131, the second side surface 132, and the third side surface 133 are all spaced apart from the inner wall of the first cavity 112. The second side surface 132 and the third side surface 133 may be two side surfaces spaced apart from each other in a second direction Y perpendicular to the first direction X. The third side surface 133 may be in contact with the inner wall surface 1121 of the first cavity 112, which may be the third side surface 133 in contact with the side surface of the second die head 12. This allows the bead 13 to be more securely connected to the second die head 12. The gap between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 forms a first flow equalizing cavity 11210. The first side surface 131 may be a side surface in the pressure strip 13 connected between the second side surface 132 and the third side surface 133 , and the gap between the first side surface 131 and the inner wall surface 1121 of the first cavity 112 forms a flow channel 11220 connecting the coating port 1410 and the first equalizing flow cavity 11210 .

[0060] In some embodiments, the cross-sectional area of ​​the first flow-distributing cavity 11210 perpendicular to the first direction X is configured to be larger than the cross-sectional area of ​​the flow channel 11220 perpendicular to the first direction X. This allows the first flow-distributing cavity 11210 to have a larger volume, enabling it to temporarily store the slurry, thereby stabilizing the pressure and facilitating a more uniform and stable output of the slurry. For example, the second side 132 and the third side 133 of the layering strip 13 are spaced apart, such that a larger gap exists between the second side 132 and the inner wall 1121 of the semicircular first cavity 112, thereby enabling storage of the slurry.

[0061] In some embodiments, the first cavity 112 and the pressure strip 13 both extend along the first direction X, and the distance between the second side surface 132 and the third side surface 133 decreases continuously along the first direction X in which the coating port 1410 moves away from the feed port 111 .

[0062] By making the first cavity 112 and the pressure strip 13 extend along the first direction X, the first flow equalizing cavity 11210 and the flow channel 11220 are continuously arranged along the first direction X. The distance between the second side 132 and the third side 133 continuously decreases along the direction in which the coating port 1410 in the first direction X is away from the feed port 111, which can mean that along the direction in which the coating port 1410 in the first direction X is away from the feed port 111, the distance between the second side 132 and the third side 133 in the second direction Y continuously decreases, so that along the direction in which the coating port 1410 in the first direction X is away from the feed port 111, the shortest part of the flow channel 11220 used to connect the coating port 1410 and the first flow equalizing cavity 11210 continuously shortens, so that the minimum length of the flow channel 11220 between the coating port 1410 close to the feed port 111 and the first flow equalizing cavity 11210 is greater than the minimum length of the flow channel 11220 between the coating port 1410 and the first flow equalizing cavity 11210 away from the feed port 111.

[0063] For example, the layering strip 13 extending along the first direction X can be composed of multiple sections, which can reduce the production cost and difficulty of the layering strip 13; the layering strip 13 can also be an integrally formed structure, so that the layering strip 13 has good overall strength. Those skilled in the art can select the composition form of the layering strip 13 according to actual conditions.

[0064] In some embodiments, the distance between the second side surface 132 and the third side surface 133 in the second direction Y is set as follows: y=ax 2 +bx+c (1)

[0065] Wherein, y is the spacing coating between the second side 132 and the third side 133 in the second direction Y, x is the distance between the coating port 1410 and the feed port 111 in the first direction X, and a, b, and c are all constants obtained based on simulation and field verification. For example, the value range of a can be -0.00003 to -0.00005, the value range of b can be 0.0001 to 0.0003, and the value range of c can be 5 to 30. In some embodiments, the value range of a can be -0.00001 to -0.00003, the value range of b can be 0.00005 to 0.0002, and the value range of c can be 10 to 25, for example, the value of a can be -0.00002, the value of b can be 0.0001, and the value of c can be 18.

[0066] In some embodiments, the spacing coating between the second side 132 and the third side 133 in the second direction Y can also be set in a linear, exponential, logarithmic or power function. Those skilled in the art can set the spacing coating between the second side 132 and the third side 133 in the second direction Y according to actual conditions.

[0067] For example, the coating die provided in the present application can be suitable for pole pieces with a width ranging from 800 mm to 2000 mm, the lengths of the first die 11 and the second die 12 in the first direction X are equal and exceed the size range of the pole piece by 100 mm to 350 mm, the size range of the first die 11 exceeding the first equalizing flow cavity 11210 in the first direction X is 65 mm to 210 mm, and the size range of the first equalizing flow cavity 11210 exceeding the pressure strip 13 in the first direction X is 3 mm to 25 mm.

[0068] For example, when the slurry formula changes, the spacing between the second side 132 and the third side 133 in the second direction Y can be changed to coat the layer strips 13 in different arrangements, so that the coating die head can improve the uniformity of the slurry coating.

[0069] In some embodiments, the first side surface 131 is configured as an arc surface.

[0070] The first side surface 131 is configured as an arc surface, which means that the cross-sectional shape of the first side surface 131 perpendicular to the first direction X is an arc, so that the first side surface 131 matches the inner wall surface 1121 of the semicircular first cavity 112, so that the slurry flows smoothly in the flow channel 11220, which is conducive to reducing the resistance during the flow of the slurry.

[0071] In some embodiments, as shown in Figure 9, the die body 1 also includes a gasket 14, which is provided with a plurality of notches 141 spaced apart along the first direction X. The gasket 14 is clamped between the first die 11 and the second die 12, and the plurality of notches 141 are all connected to the flow channel 11220 to form a coating port 1410.

[0072] The gasket 14 can be a component for forming a plurality of coating ports 1410. The gasket 14 is provided with a plurality of notches 141 spaced apart along the first direction X. The notches 141 are provided along the thickness direction of the gasket 14 and are connected to the edge of the gasket 14. As shown in FIG10 , by sandwiching the gasket 14 between the first die head 11 and the second die head 12 and connecting the notches 141 on the gasket 14 with the flow channel 11220, the gasket 14, the first die head 11 and the second die head 12 can form a plurality of coating ports 1410 connected to the flow channel 11220 and the outside world, so that the slurry in the first flow equalizing cavity 11210 can flow into the notches 141 and flow out to the outside world for coating.

[0073] In some embodiments, the notch 141 on the gasket 14 can be made simultaneously with the gasket 14 using an integral molding processing method such as casting, so that the gasket 14 with the notch 141 can be manufactured as a whole synchronously, which not only makes the processing and manufacturing of the gasket 14 convenient, but also makes the overall structure of the gasket 14 have good strength; the notch 141 can also be made by machining the entire blank of the gasket 14 using machining methods such as milling, so that the gasket 14 has lower processing difficulty and processing cost.

[0074] In some embodiments, the die body 1 further includes a connector 15 , a through hole 142 is provided on the gasket 14 , and the connector 15 passes through the bead 13 and the through hole 142 and is connected to the second die 12 to fix the bead 13 to the second die 12 .

[0075] The connector 15 may be a connecting member for connecting the bead 13 to the second die head 12. The through hole 142 provided on the gasket 14 may be a hole-like structure that penetrates the gasket 14 along the thickness direction of the gasket 14. The bead 13 connected to the connector 15 passes through the through hole 142 and is connected to the second die head 12, thereby connecting the connector 15 to the second die head 12.

[0076] Exemplarily, the connecting member 15 can be a connecting bolt, a countersunk hole is provided on the pressure strip 13, and a threaded hole is provided on the side of the second die head 12 facing the first die head 11. The connecting bolt passes through the countersunk hole and the through hole 142 in sequence and is screwed into the threaded hole. The pressure strip 13 is connected to the second die head 12, and part of the gasket 14 is clamped between the pressure strip 13 and the second die head 12.

[0077] In some embodiments, the first die head 11 is provided with a second cavity 113 , and the second die head 12 covers the second cavity 113 to form a second flow balancing cavity 11310 . The second flow balancing cavity 11310 is connected to the plurality of coating ports 1410 .

[0078] The second cavity 113 may be a groove-shaped structure opened by the first die head 11 . The second die head 12 covers the second cavity 113 , so that the second cavity 113 forms a second flow balancing cavity 11310 communicating with the plurality of coating ports 1410 .

[0079] Exemplarily, the second cavity 113 extends along the first direction X, so that the second equalizing flow cavity 11310 formed by the second cavity 113 can connect multiple coating ports 1410 spaced apart along the first direction X. The second cavity 113 can temporarily store the slurry flowing to the coating port 1410, which is conducive to making the output of the slurry more uniform and stable.

[0080] Exemplarily, the second cavity 113 is opened on the side of the first die head 11 facing the second die head 12. In the third direction Z perpendicular to the first direction X, the second cavity 113 is arranged parallel to the first cavity 112 and spaced apart. When the slurry flows into the coating port 1410 from the flow channel 11220, the slurry can flow into the second equal flow cavity 11310 formed by the second cavity 113.

[0081] In some embodiments, the coating die further includes a first adjusting rod 2 and a second adjusting rod 3 , the first adjusting rod 2 is connected to the first die 11 , the second adjusting rod 3 is connected to the second die 12 , and the first adjusting rod 2 and the second adjusting rod 3 are used to adjust the opening size of the coating port 1410 .

[0082] The first adjustment rod 2 and the second adjustment rod 3 are both rod-shaped components used to adjust the opening size of the coating port 1410 of the coating die. The first adjustment rod 2 is connected to the first die 11, and the second adjustment rod 3 is connected to the second die 12. The operator can use the first adjustment rod 2 to move the first die 11 to adjust the opening size of the coating port 1410, and can also use the second adjustment rod 3 to move the second die 12 to adjust the opening size of the coating port 1410, thereby adjusting the coating weight of the slurry by the coating die.

[0083] In some embodiments, there are multiple first adjustment rods 2 , which are spaced apart along the first direction X. There are multiple second adjustment rods 3 , which are spaced apart along the first direction X.

[0084] By providing a plurality of first adjustment rods 2 arranged at equal intervals along the first direction X on the first die head 11, an operator can individually adjust the openings of the plurality of coating ports 1410 arranged at intervals along the first direction X through the plurality of first adjustment rods 2, so that the weight of the slurry coated at the coating ports 1410 can be flexibly adjusted. By providing a plurality of second adjustment rods 3 arranged at equal intervals along the first direction X on the second die head 12, an operator can individually adjust the openings of the plurality of coating ports 1410 arranged at intervals along the first direction X through the plurality of second adjustment rods 3, so that the weight of the slurry coated at the coating ports 1410 can be flexibly adjusted.

[0085] According to some embodiments of the present application, the present application provides a coating die head, which includes a die head body 1, a first adjustment rod 2 and a second adjustment rod 3, the die head body 1 includes a first die head 11, a second die head 12, a pressure strip 13 and a gasket 14, the first die head 11 is provided with a feed port 111 and a first cavity 112 and a second cavity 113 extending along a first direction X, the feed port 111 is connected to the first cavity 112, the first cavity 112 and the second cavity 113 are arranged at intervals, the gasket 14 is provided with a plurality of notches 141 at intervals along the first direction X, the gasket 14 It is clamped between the first die head 11 and the second die head 12, and the notch 141 of the gasket 14 forms a coating port 1410 with the first die head 11 and the second die head 12. The pressure strip 13 is connected to the second die head 12 and placed in the first cavity 112. A flow channel 11220 is formed between the first side surface 131 of the pressure strip 13 and the inner wall surface 1121 of the first cavity 112, and a first equalizing flow cavity 11210 is formed between the second side surface 132 and the inner wall surface 1121 of the first cavity 112. The flow channel 11220 connects the first equalizing flow cavity 11210 with multiple coating ports 1410.

[0086] The second side surface 132 and the third side surface 133 in the pressure strip 13 are arranged relative to each other in the second direction Y. Since the spacing between the second side surface 132 and the third side surface 133 continuously decreases in the direction of the coating port 1410 away from the feed port 111 in the first direction X, the minimum length of the flow channel 11220 between the coating port 1410 close to the feed port 111 and the first flow equalizing cavity 11210 is greater than the minimum length of the flow channel 11220 between the coating port 1410 away from the feed port 111 and the first flow equalizing cavity 11210, so that the pressure lost by the slurry flowing to the coating port 1410 away from the feed port 111 during the flow process is less than the pressure lost by the slurry flowing to the coating port 1410 close to the feed port 111 during the flow process, which is beneficial to balancing the pressure of the slurry at multiple coating ports 1410 and improving the consistency of the discharge of multiple coating ports 1410.

[0087] Some embodiments of the present application also provide a coating device for a pole piece, which includes a coating die provided by the aforementioned technical solution, and the coating die is used to coat slurry on the surface of the pole piece.

[0088] Since the coating device for the pole piece includes the coating die provided by the above technical solution, the coating device for the pole piece can improve the uniformity of slurry coating in the coating process.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A coating die head, characterized in that: include: The die body is provided with a feed port, a first flow balancing chamber, a flow channel and a plurality of coating ports, wherein the first flow balancing chamber extends along a first direction and is connected to the feed port, the plurality of coating ports are arranged at intervals along the first direction, and the flow channel is used to connect the first flow balancing chamber and the plurality of coating ports; Among the plurality of coating ports, along the direction in which the coating port is away from the feed port, the minimum length of the flow channel between the coating port and the first flow equalizing cavity tends to decrease.

2. The coating die head according to claim 1, characterized in that: The die body includes a first die, a second die and a pressure strip, the first die includes a first cavity and the feed port connected to the first cavity, the second die is connected to the pressure strip and covers the first cavity, the pressure strip is spaced apart from at least part of the inner wall of the first cavity, and the gap between the pressure strip and the inner wall of the first cavity forms the flow channel and the first flow equalizing cavity.

3. The coating die head according to claim 2, characterized in that: The pressure strip includes a first side surface, a second side surface and a third side surface, the second side surface and the third side surface are arranged relatively spaced apart in the second direction, the first side surface is connected between the second side surface and the third side surface, the third side surface is attached to the inner wall surface of the first cavity, the flow channel is formed between the first side surface and the inner wall surface of the first cavity, the first flow equalizing cavity is formed between the second side surface and the inner wall surface of the first cavity, and the second direction is perpendicular to the first direction.

4. The coating die head according to claim 2 or 3, characterized in that: The die body also includes a gasket, which is provided with a plurality of notches at intervals along the first direction, and the gasket is sandwiched between the first die and the second die, and the plurality of notches are all connected to the flow channel to form the coating port.

5. The coating die head according to any one of claims 2 to 4, characterized in that: The first die head is provided with a second cavity, and the second die head covers the second cavity to form a second flow-distributing cavity, and the second flow-distributing cavity is communicated with the plurality of coating ports.

6. The coating die head according to any one of claims 2 to 5, characterized in that: The coating die head also includes a first adjusting rod and a second adjusting rod, the first adjusting rod is connected to the first die head, the second adjusting rod is connected to the second die head, and the first adjusting rod and the second adjusting rod are used to adjust the opening size of the coating port.

7. The coating die head according to claim 3, characterized in that: The first cavity and the pressure strip both extend along the first direction, and the distance between the second side surface and the third side surface continuously decreases along the direction in which the coating port is away from the feed port in the first direction.

8. The coating die head according to claim 3 or 7, characterized in that: The first side surface is configured as an arc surface.

9. The coating die head according to claim 4, characterized in that: The die body also includes a connecting piece, a through hole is provided on the gasket, and the connecting piece passes through the pressure strip and the through hole and is connected to the second die to fix the pressure strip to the second die.

10. The coating die head according to claim 6, characterized in that: There are a plurality of first adjustment rods, and the plurality of first adjustment rods are arranged at intervals along the first direction. There are a plurality of second adjustment rods, and the plurality of second adjustment rods are arranged at intervals along the first direction.

11. A coating device for a pole piece, characterized in that: It comprises a coating die as described in any one of claims 1 to 10, wherein the coating die is used to coat slurry onto the surface of a pole piece.

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