Coating die head, and coating device for electrode sheet

Abstract

Provided in the present application are a coating die head, and a coating device for an electrode sheet. The coating die head is provided with a feeding channel, a first flow homogenization cavity and a plurality of coating ports arranged at intervals in a first direction, wherein the first flow homogenization cavity extends in the first direction and is in communication with the feeding channel; the first flow homogenization cavity is in communication with the plurality of coating ports; two ends of the feeding channel are respectively a feeding port and a connecting port connected to the first flow homogenization cavity; and from the feeding port to the connecting port, the size of the cross section of the feeding channel in the first direction tends to increase. By means of the above arrangement, the pressure of slurry at the plurality of coating ports can be balanced, thus improving the discharge consistency of the plurality of coating ports and the uniformity of slurry coating.

Description

Coating die and electrode coating device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202321692795.8, filed on June 30, 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, some embodiments of the present application provide a coating die head, which is provided with a feed channel, a first flow equalizing chamber and a plurality of coating ports, wherein the plurality of coating ports are arranged at intervals along a first direction and are connected to the first flow equalizing chamber; a feed port and a connection port are respectively provided at both ends of the feed channel, and the connection port is connected to the first flow equalizing chamber; from the feed port to the connection port, the size of the cross section of the feed channel in the first direction tends to increase.

[0009] Since the cross-section of the feed channel in the first direction tends to increase from the feed port to the connecting port, the flow distance of the slurry from the connecting port to the coating port away from the feed channel can be reduced, thereby reducing the pressure lost during the flow process, which is beneficial to increasing the pressure of the slurry at the coating port away from the feed channel, balancing the pressure of the slurry at multiple coating ports, and is beneficial to improving the consistency of the discharge of multiple coating ports, thereby improving the uniformity of the slurry coating in the coating process.

[0010] According to the coating die provided in some embodiments of the present application, the feed channel has a trumpet-shaped structure, and the large-diameter end of the trumpet-shaped structure is the feed port, so that the size of the feed channel in the first direction can continuously increase along the extension direction from the feed port to the connecting port.

[0011] According to the coating die provided in some embodiments of the present application, the feed channel includes a first part and a second part that are connected, the second part connects the first part and the first equalizing flow chamber, the feed port is arranged at the end of the first part away from the second part, and the connection port is arranged at the end of the second part away from the first part, and the cross-sectional area of ​​the second part is larger than the cross-sectional area of ​​the first part; the shape of the cross section of the first part perpendicular to the second direction is circular, and the shape of the cross section of the second part perpendicular to the second direction is elliptical, and the major axis of the ellipse is arranged along the first direction, so that the connection port of the feed channel continuously expands outward in the first direction.

[0012] According to some embodiments of the present application, the coating die includes a first die, a second die and a pressure strip. The first die is provided with a first cavity and a feed channel 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. The gap between the pressure strip and the inner wall of the first cavity forms a first flow equalization cavity.

[0013] According to the coating die provided in some embodiments of the present application, the inner wall surface of the first cavity is configured as a circular arc surface, and at least part of the inner wall surface of the feed channel at the feed port is tangent to the inner wall surface of the first cavity. This not only reduces the pressure lost in the process of the slurry flowing from the feed channel into the first cavity, but also reduces the pressure lost when the slurry flows in the first cavity, which is beneficial to increasing the pressure of the slurry at each coating port.

[0014] According to some embodiments of the present application, the coating die further includes a gasket having a plurality of notches spaced apart along a first direction. The gasket is clamped between the first die and the second die, and the plurality of notches are connected to the first flow equalization cavity to form a coating port.

[0015] 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.

[0016] According to the coating die provided in some embodiments of the present application, the first flow-distributing cavity includes a material storage portion and a connecting portion that are connected. The material storage portion, the connecting portion and the pressure strip all extend along the first direction, and the connecting portion connects multiple coating ports with the material storage portion.

[0017] 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.

[0018] According to some embodiments of the present application, the coating die also includes a connecting piece, a through hole is provided on the gasket, and the pressure strip is fixed to the second die by the connecting piece passing through the through hole. The connecting piece can detachably connect the pressure strip to the second die, making it easy to disassemble the pressure strip.

[0019] According to the coating die provided in some embodiments of the present application, the pressure strip includes a first side, a second side and a third side, the second side and the third side are spaced apart, the first side is connected between the second side and the third side, the third side is attached to the inner wall surface of the first cavity, a connecting portion is formed between the first side and the inner wall surface of the first cavity, and a material storage portion is formed between the second side and the inner wall surface of the first cavity.

[0020] 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. The operator can individually adjust the openings of the multiple coating ports arranged at intervals along the first direction through the multiple first adjustment rods and the multiple second adjustment rods, so that the weight of the slurry coated at the coating port can be flexibly adjusted.

[0021] According to the coating die provided in some embodiments of the present application, the first side surface is configured as an arc, and the first side surface matches the inner wall surface of the first cavity, so that the slurry flows smoothly in the first flow-distributing cavity, which is beneficial to reducing the resistance during the flow of the slurry.

[0022] 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.

[0023] The technical solutions provided by the embodiments of the present disclosure bring at least the following beneficial effects:

[0024] The present application provides a coating die head, which is provided with a feed channel, a first flow balancing chamber and a plurality of coating ports, wherein the first flow balancing chamber extends along a first direction and is connected to the feed channel, the plurality of coating ports are spaced apart along the first direction, the first flow balancing chamber is connected to the plurality of coating ports, the two ends of the feed channel are respectively a feed port and a connection port connected to the first flow balancing chamber, and the cross-section of the feed channel in the first direction tends to increase from the feed port to the connection port. Since the size of the feed channel in the first direction gradually increases from the feed port to the connection port, the flow distance of the slurry from the connection port to the coating port away from the feed channel can be reduced, thereby reducing the pressure lost during the flow process, which is conducive to increasing the pressure of the slurry at the coating port away from the feed channel, balancing the pressure of the slurry at the plurality of coating ports, and is conducive to improving the consistency of the discharge of the plurality of coating ports, thereby improving the uniformity of the slurry coating in the coating process.

[0025] 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

[0026] 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:

[0027] FIG1 is a perspective view of a coating die provided in some embodiments of the present application;

[0028] Figure 2 is a cross-sectional view of point A in Figure 1;

[0029] FIG3 is a cross-sectional view of a feed channel of a coating die provided in some embodiments of the present application;

[0030] FIG4 is a schematic structural diagram of a first die head and a pressure strip provided in some embodiments of the present application;

[0031] FIG5 is a schematic structural diagram of a first die head provided in some embodiments of the present application;

[0032] FIG6 is a schematic diagram of a partial structure of a coating die provided in some embodiments of the present application;

[0033] FIG7 is a schematic structural diagram of a coating die provided in some embodiments of the present application;

[0034] FIG8 is an enlarged view of point B in FIG7 .

[0035] The figure numbers in the specific implementation manner are as follows: 11, first die head; 111, feed channel; 1111, first part; 11110, feed port; 1112, second part; 11120, connecting port; 112, first cavity; 1121, inner wall surface; 1120, first flow equalizing cavity; 11201, material storage part; 11202, connecting part; 113, second cavity; 11310, second flow equalizing cavity; 12, second die head; 13, pressure strip; 131, first side; 132, second side; 133, third side; 14, gasket; 141, notch; 142, through hole; 1410, coating port; 15, connecting piece; 16, first adjusting rod; 17, 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 this application, unless otherwise explicitly 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 intermediary. Furthermore, a first feature being "above," "above," or "above" a second feature may mean that the first feature is directly above or diagonally 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," or "below" a second feature may mean that the first feature is directly below or diagonally 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 channel, the slurry flow rate at the coating port close to the feed channel is greater than the slurry flow rate at the coating port far from the feed channel due to the inertia of the slurry flowing from the feed channel and the pressure loss of the slurry away from the feed channel. 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 channel, a first flow balancing chamber and a plurality of coating ports, wherein the first flow balancing chamber extends along a first direction and is connected to the feed channel, the plurality of coating ports are arranged at intervals along the first direction, the first flow balancing chamber is connected to the plurality of coating ports, the two ends of the feed channel are respectively a feed port and a connecting port connected to the first flow balancing chamber, and the size of the feed channel in the first direction gradually increases from the feed port to the connecting port. Since the size of the feed channel in the first direction gradually increases from the feed port to the connecting port, the flow distance of the slurry from the connecting port to the coating port away from the feed channel can be reduced, thereby reducing the pressure lost during the flow process, which is conducive to increasing the pressure of the slurry at the coating port away from the feed channel, balancing the pressure of the slurry at the plurality of coating ports, and is conducive to improving the consistency of the discharge of the plurality of coating ports, thereby improving the uniformity of the 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] As shown in Figure 1, some embodiments of the present application provide a coating die head. As shown in Figure 2, the coating die head is provided with a feed channel 111, a first flow equalizing chamber 1120 and a plurality of coating ports 1410. The plurality of coating ports 1410 are arranged at intervals along the first direction X and are connected to the first flow equalizing chamber 1120; a feed port 11110 and a connection port 11120 are respectively provided at both ends of the feed channel 111, and the connection port 11120 is connected to the first flow equalizing chamber 1120; from the feed port 11110 to the connection port 11120, the size of the cross section of the feed channel 111 in the first direction X tends to increase.

[0049] Exemplarily, the coating die can be a component in a coating device that coats the slurry on the surface of the pole piece during the coating process. After the slurry enters the coating die, it is simultaneously coated on multiple locations of the pole piece under the action of the coating die to achieve efficient coating on the pole piece.

[0050] The feed channel 111 may be a slurry channel provided on the coating die head. The feed channel 111 may be in communication with the outside world. The feed channel 111 is used to allow the slurry to pass into the coating die head. The feed port 11110 and the connection port 11120 respectively refer to the ports at both ends of the feed channel 111 in its own extension direction. The feed port 11110 may be the port through which the feed channel 111 communicates with the outside world. The slurry may pass into the feed channel 111 from the feed port 11110. The connection port 11120 may be the port through which the feed channel 111 communicates with the first flow equalizing chamber 1120. The slurry in the feed channel 111 may flow into the first flow equalizing chamber 1120 from the connection port 11120. Exemplarily, the connection between the connection port 11120 and the first flow equalizing chamber 1120 may be that the connection port 11120 is directly connected to the inner wall of the first flow equalizing chamber 1120 , so that the feed channel 111 is connected to the first flow equalizing chamber 1120 through the connection port 11120 .

[0051] Among them, along the direction from the feed port 11110 to the connecting port 11120, by setting the size of the cross-section of the feed channel 111 in the first direction X to increase, the flow distance of the slurry from the connecting port 11120 to the coating port 1410 away from the feed channel 111 can be shortened, thereby reducing the pressure lost by the slurry during the flow process, which is beneficial to increase the pressure of the slurry at the coating port 1410 away from the feed channel 111, and helps to balance the slurry pressure at multiple coating ports 1410 at different distances from the feed channel 111, which is beneficial to improve the consistency of the discharge of multiple coating ports 1410.

[0052] The first flow equalization cavity 1120 may be a cavity structure provided in the coating die head, which is extended along the first direction X in the coating die head and communicated with the connection port 11120 of the feed channel 111 and the multiple coating ports 1410, so that the slurry flowing in from the feed channel 111 can be distributed and temporarily stored in the coating die head along the first direction X, so as to facilitate subsequent flow to the multiple coating ports 1410.

[0053] The coating port 1410 may be an opening structure provided on the coating die head, which is used for the slurry to flow out so that the slurry can be coated on the surface of the electrode.

[0054] Exemplarily, there are multiple coating ports 1410 , which are spaced apart along the first direction X, so that the coating die head 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 head.

[0055] Through the above structure, the size of the feed channel 111 in the first direction X gradually increases from the feed port 11110 to the connecting port 11120, which can reduce the flow distance of the slurry from the connecting port 11120 to the coating port 1410 away from the feed channel 111, thereby reducing the pressure lost by the slurry during the flow process, which is beneficial to increase the pressure of the slurry at the coating port 1410 away from the feed channel 111, balance the pressure of the slurry at multiple coating ports 1410, and help improve the consistency of the discharge of multiple coating ports 1410, thereby improving the uniformity of slurry coating in the coating process.

[0056] In some embodiments, the feed channel 111 is a trumpet-shaped structure, the small end of the trumpet-shaped structure is the feed port 11110 , and the large end of the trumpet-shaped structure is configured as the connection port 11120 .

[0057] By setting the feed channel 111 to be a trumpet-shaped structure, and configuring the small end of the trumpet-shaped structure as the feed port 11110, and configuring the large end of the trumpet-shaped structure as the connection port 11120, the size of the set feed channel 1111 in the first direction X can be continuously increased along the extension direction from the feed port 11110 to the connection port 11120, so that the feed channel 111 can meet the requirements to reduce the flow distance of the slurry from the connection port 11120 to the coating port 1410 away from the feed channel 111.

[0058] In some embodiments, as shown in Figure 3, the feed channel 111 includes a first portion 1111 and a second portion 1112 that are connected, the second portion 1112 connects the first portion 1111 and the first flow equalizing chamber 1120, the feed port 11110 is arranged at the end of the first portion 1111 away from the second portion 1112, and the connection port 11120 is arranged at the end of the second portion 1112 away from the first portion 1111; the shape of the cross-section of the first portion 1111 perpendicular to the second direction Y is circular, and the shape of the cross-section of the second portion 1112 perpendicular to the second direction Y is elliptical; the major axis of the ellipse is arranged along the first direction X, and the second direction Y is perpendicular to the first direction X.

[0059] The first portion 1111 and the second portion 1112 refer to different portions of the feed channel 111, respectively. The two portions are interconnected, and when the slurry flows in the feed channel 111, it flows sequentially between the first portion 1111 and the second portion 1112. The second portion 1112 may be the portion of the feed channel 111 that is connected to the first flow equalizing chamber 1120. It is connected between the first portion 1111 and the first flow equalizing chamber 1120. The end of the second portion 1112 away from the first portion 1111 is provided with a connection port 11120. The second portion 1112 is connected to the first flow equalizing chamber 1120 through the connection port 11120. The first portion 1111 may be the portion of the feed channel 111 that is connected to the outside world. The end of the second portion 1112 away from the second portion 1112 is provided with a feed port 11110. The slurry from the outside world enters the feed channel 111 through the feed port 11110.

[0060] The cross-section of the first portion 1111 perpendicular to the second direction Y is circular, which may refer to the circular cross-section of the first portion 1111 perpendicular to the second direction Y. This reduces the resistance encountered by the slurry when flowing through the first portion 1111. The cross-section of the second portion 1112 perpendicular to the second direction Y is elliptical, which may refer to the elliptical cross-section of the second portion 1112 perpendicular to the second direction Y. This results in an arcuate inner wall surface 1121 of the second portion 1112, reducing the resistance encountered by the slurry when flowing through the second portion 1112. The major axis of the ellipse is arranged along the first direction X, resulting in a larger dimension of the second portion 1112 in the first direction X. This allows the second portion 1112 to shorten the distance between the connection port 11120 and the coating port 1410 away from the feed channel 111, thereby reducing the distance the slurry flows from the connection port 11120 to the coating port 1410 away from the feed channel 111.

[0061] For example, the first portion 1111 may be configured as a cylindrical structure, wherein the diameter of the cylindrical structure may range from 25 mm to 50 mm, and the length of the cylindrical structure may range from 2 mm to 15 mm. In some embodiments, the diameter of the first portion 1111 in the cylindrical structure may range from 30 mm to 45 mm, and the length of the cylindrical structure may range from 2 mm to 10 mm. For example, the diameter of the first portion 1111 in the cylindrical structure may range from 36 mm, and the length of the cylindrical structure may range from 5 mm.

[0062] In some embodiments, the inner wall surface 1121 of the second portion 1112 is a gradually changing arcuate surface. The connection between the first portion 1111 and the second portion 1112 is the starting position of the gradual change. The second and third positions of the gradual change are spaced apart from the starting position, and the starting position, the second position, and the third position are continuously closer to the first flow equalizing cavity 1120. The cross-sections of the second and third positions of the gradually changing second portion 1112 perpendicular to the second direction Y are both elliptical. The inner wall surface 1121 of the second portion 1112 is formed by the gradual change of the cross-sections at the starting position, the second position, and the third position.

[0063] Illustratively, the distance between the second position and the starting position in the second direction Y ranges from 10 mm to 30 mm, the major axis of the elliptical cross-section perpendicular to the second direction Y ranges from 20 mm to 40 mm, and the minor axis is equal to the diameter of the first portion 1111. In some embodiments, the distance between the second position and the starting position in the second direction Y ranges from 15 mm to 25 mm, and the major axis of the elliptical cross-section perpendicular to the second direction Y ranges from 25 mm to 35 mm. For example, the distance between the second position and the starting position in the second direction Y may be 20 mm, and the major axis of the elliptical cross-section perpendicular to the second direction Y may be 30 mm.

[0064] The third position can be set at the center plane of the first flow balancing cavity 1120. The long axis of the elliptical cross-section perpendicular to the second direction Y ranges from 60 mm to 160 mm, and the short axis ranges from 3 mm to 15 mm. The edge of the elliptical cross-section is flush with the inner wall surface 1121 of the first flow balancing cavity 1120. In some embodiments, the long axis of the elliptical cross-section perpendicular to the second direction Y at the third position can range from 70 mm to 150 mm, and the short axis range can range from 3 mm to 10 mm. For example, the long axis of the elliptical cross-section perpendicular to the second direction Y at the third position is 110 mm, and the short axis is 5 mm.

[0065] In some embodiments, the coating die includes a first die 11, a second die 12 and a pressure strip 13. The first die 11 is provided with a first cavity 112 and a feed channel 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 first flow equalization cavity 1120.

[0066] The first die head 11, the second die head 12 and the pressure strip 13 can all be components in the coating die head. When they are connected to form the coating die head, they can also form structures such as the first flow equalization cavity 1120 in the coating die head. 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 1120; the pressure strip 13 can be a strip-shaped component extending along the first direction X, which is connected to the second die head 12, 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 4, by spacing the pressure strip 13 from at least part of the inner wall of the first cavity 112, a first flow equalization cavity 1120 extending along the first direction X is formed between the pressure strip 13 and the inner wall of the first cavity 112.

[0067] In some embodiments, the inner wall surface 1121 of the first cavity 112 is configured as an arc surface, and at least a portion of the inner wall of the feed channel 111 at the feed port 11110 is tangent to the inner wall surface 1121 of the first cavity 112 .

[0068] By configuring the inner wall surface 1121 of the first cavity 112 as a circular arc surface and making at least part of the inner wall of the feed channel 111 at the feed port 11110 tangent to the inner wall surface 1121 of the first cavity 112, not only is the pressure lost in the process of the slurry flowing from the feed channel 111 into the first cavity 112 reduced, but the pressure lost when the slurry flows in the first cavity 112 can also be reduced, which is beneficial to increasing the pressure of the slurry at each coating port 1410.

[0069] As shown in Figure 5, the first cavity 112 is opened on the side of the first die head 11 facing the second die head 12, the feed channel 111 is arranged on the first die head 11 and is connected to the first cavity 112, the pressure strip 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 pressure strip 13 connected to the second die head 12 is placed in the first cavity 112, and a first equalizing flow cavity 1120 is formed between the pressure strip 13 and the inner wall surface 1121 of the first cavity 112 on the first die head 11, and the first equalizing flow cavity 1120 extending along the first direction X is connected to multiple coating ports 1410 distributed along the first direction X.

[0070] In some embodiments, the first flow equalization cavity 1120 includes a connected material storage portion 11201 and a connecting portion 11202. The material storage portion 11201, the connecting portion 11202 and the pressure strip 13 all extend along the first direction X. The connecting portion 11202 connects the multiple coating ports 1410 with the material storage portion 11201.

[0071] The material storage portion 11201 and the connecting portion 11202 can be different parts of the first flow-distributing cavity 1120, and both are formed by the gap between the bead 13 and the inner wall 1121 of the first cavity 112 on the first die head 11. The material storage portion 11201 can be a portion that can temporarily store slurry, which can stabilize the pressure of the slurry and facilitate more uniform and stable slurry output. The connecting portion 11202 can be a portion that connects the material storage portion 11201 with the coating ports 1410, allowing the slurry in the material storage portion 11201 to flow smoothly to each coating port 1410. By extending the first cavity 112 and the bead 13 along the first direction X, the connecting portion 11202 can connect multiple coating ports 1410 spaced apart along the first direction X with the material storage portion 11201.

[0072] For example, in the cross section perpendicular to the first direction X, the cross-sectional area of ​​the storage portion 11201 is larger than the cross-sectional area of ​​the connecting portion 11202, so that the storage portion 11201 can temporarily store enough slurry and can play a sufficient pressure stabilizing role on the slurry, which is conducive to making the output of the slurry more uniform and stable.

[0073] In some embodiments, the pressure strip 13 includes a first side 131, a second side 132 and a third side 133, the second side 132 and the third side 133 are spaced apart, the first side 131 is connected between the second side 132 and the third side 133, the third side 133 is attached to the inner wall surface 1121 of the first cavity 112, a connecting portion 11202 is formed between the first side 131 and the inner wall surface 1121 of the first cavity 112, and a material storage portion 11201 is formed between the second side 132 and the inner wall surface 1121 of the first cavity 112.

[0074] 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 third direction Z 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 the material storage portion 11201. 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 connecting portion 11202 connecting the coating port 1410 and the first flow equalizing cavity 1120 .

[0075] In some embodiments, the first side surface 131 is configured as an arc surface.

[0076] 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 first flow equalization cavity 1120, which is conducive to reducing the resistance during the flow of the slurry.

[0077] In some embodiments, as shown in Figure 6, the coating die 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 first flow equalization cavity 1120 to form a coating port 1410.

[0078] 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 Figures 7 and 8, 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 first flow equalizing cavity 1120, 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 first flow equalizing cavity 1120 and the outside world, so that the slurry in the first flow equalizing cavity 1120 can flow out to the outside world by flowing into the notches 141 for coating.

[0079] 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.

[0080] In some embodiments, the coating die further includes a connector 15 , a through hole 142 is provided on the gasket 14 , and the pressure strip 13 is fixed to the second die 12 via the connector 15 passing through the through hole 142 .

[0081] 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 penetrating the gasket 14 along the thickness direction of the gasket 14. The bead 13 may be fixed to the second die head 12 via the connector 15 passing through the through hole 142. The bead 13 connected to the connector 15 may pass through the through hole 142 and be connected to the second die head 12, thereby connecting the connector 15 to the second die head 12.

[0082] 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.

[0083] 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 .

[0084] 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 .

[0085] 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.

[0086] Exemplarily, the second cavity 113 is opened on the side of the first die head 11 facing the second die head 12. In the second direction Y 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 first flow equalizing cavity 1120, the slurry can flow into the second flow equalizing cavity 11310 formed by the second cavity 113.

[0087] In some embodiments, the coating die further includes a first adjusting rod 16 and a second adjusting rod 17 , the first adjusting rod 16 is connected to the first die 11 , and the second adjusting rod 17 is connected to the second die 12 , and the first adjusting rod 16 and the second adjusting rod 17 are used to adjust the opening size of the coating port 1410 .

[0088] The first adjustment rod 16 and the second adjustment rod 17 are both rod-shaped components used to adjust the opening size of the coating port 1410 of the coating die. The first adjustment rod 16 is connected to the first die 11, and the second adjustment rod 17 is connected to the second die 12. The operator can use the first adjustment rod 16 to move the first die 11 to adjust the opening size of the coating port 1410, and can also use the second adjustment rod 17 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.

[0089] In some embodiments, a plurality of first adjustment rods 16 are provided, and the plurality of first adjustment rods 16 are arranged at intervals along the first direction X; a plurality of second adjustment rods 17 are provided, and the plurality of second adjustment rods 17 are arranged at intervals along the first direction X.

[0090] By providing a plurality of first adjustment rods 16 equally spaced 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 spaced along the first direction X through the plurality of first adjustment rods 16, 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 17 equally spaced 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 spaced along the first direction X through the plurality of second adjustment rods 17, so that the weight of the slurry coated at the coating ports 1410 can be flexibly adjusted.

[0091] In some embodiments, the coating die head includes a first die head 11, a second die head 12, a pressure strip 13, a gasket 14, a first adjustment rod 16 and a second adjustment rod 17, the first die head 11 is provided with a feed channel 111 and a first cavity 112 and a second cavity 113 extending along a first direction X, the feed channel 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, and the gasket 14 is clamped between the first die head 11 and the second cavity 113. Between the die heads 12, 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 connecting portion 11202 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 material storage portion 11201 is formed between the second side surface 132 and the inner wall surface 1121 of the first cavity 112, and the connecting portion 11202 connects the material storage portion 11201 with multiple coating ports 1410.

[0092] The feed channel 111 is connected to the storage portion 11201 through the connecting port 11120, and is connected to the outside world through the feed port 11110. The feed channel 111 is configured to have a trumpet-shaped structure. From the feed port 11110 to the connecting port 11120, the size of the feed channel 111 in the first direction X gradually increases, which can reduce the flow distance of the slurry from the connecting port 11120 to the coating port 1410 away from the feed channel 111, thereby helping to reduce the pressure lost by the slurry during the flow process, and helping to increase the pressure of the slurry at the coating port 1410 away from the feed channel 111, so that the pressure of the slurry at multiple coating ports 1410 is balanced.

[0093] 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.

[0094] 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, comprising a feed channel, a first flow balancing chamber and a plurality of coating ports, wherein the plurality of coating ports are arranged at intervals along a first direction and connected to the first flow balancing chamber; A feed port and a connection port are respectively provided at both ends of the feed channel, and the connection port is communicated with the first flow equalization cavity; from the feed port to the connection port, the size of the cross section of the feed channel in the first direction tends to increase.

2. The coating die head according to claim 1, wherein: The feed channel includes a first part and a second part that are connected, the second part connects the first part and the first flow equalizing chamber, the feed port is arranged at the end of the first part away from the second part, the connection port is arranged at the end of the second part away from the first part, and the cross-sectional area of ​​the second part is larger than the cross-sectional area of ​​the first part.

3. The coating die head according to claim 2, wherein: The coating die includes a first die, a second die and a pressure strip, the first die is provided with a first cavity and the feed channel 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 first flow equalization cavity.

4. The coating die head according to claim 3, wherein: The inner wall surface of the first cavity is configured as an arc surface, and at least a portion of the inner wall surface of the feed channel at the feed port is tangent to the inner wall surface of the first cavity.

5. The coating die head according to claim 4, wherein: The coating die head also includes a gasket, which is provided with a plurality of notches at intervals along the first direction, and the gasket is clamped between the first die head and the second die head, and the plurality of notches are all connected to the first flow balancing cavity to form the coating port.

6. The coating die head according to any one of claims 3 to 5, wherein: 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.

7. The coating die head according to any one of claims 3 to 6, wherein: The first flow-distributing cavity comprises a material storage portion and a connecting portion which are connected. The material storage portion, the connecting portion and the pressure strip all extend along the first direction. The connecting portion connects the plurality of coating ports with the material storage portion.

8. The coating die head according to any one of claims 3 to 7, wherein: 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.

9. The coating die head according to claim 5, wherein: The coating die head also includes a connecting piece, the gasket is provided with a through hole, and the pressure strip is fixed to the second die head by the connecting piece passing through the through hole.

10. The coating die head according to claim 7, wherein: The pressure strip includes a first side surface, a second side surface and a third side surface, the second side surface is spaced apart from the third side surface, 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 connecting portion is formed between the first side surface and the inner wall surface of the first cavity, and the material storage portion is formed between the second side surface and the inner wall surface of the first cavity.

11. The coating die head according to claim 8, wherein: 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.

12. The coating die according to claim 10, wherein: The first side surface is configured as an arc surface.

13. A coating device for a pole piece, comprising a coating die head as claimed in any one of claims 1 to 12, wherein the coating die head is used for coating slurry onto the surface of the pole piece.

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