Coating die and electrode sheet coating device

Abstract

A coating die and an electrode sheet coating device. The coating die is provided with a feeding port (111), a first flow equalizing cavity (11210), a flow channel (11220), and a plurality of coating ports (1410); the first flow equalizing cavity (11210) extends in a first direction and is in communication with the feeding port (111); the plurality of coating ports (1410) are arranged at intervals in a first direction; the flow channel (11220) is used for making the first flow equalizing cavity (11210) communicated with the plurality of coating ports (1410). Since the minimum cross-sectional area of the flow channel (11220) between the plurality of coating ports (1410) and the first flow equalizing cavity (11210) is sequentially increased in a direction from the coating port (1410) close to the feeding port (111) to the coating port (1410) distant from the feeding port (111), the pressure loss during flowing of a slurry flowing to the coating port (1410) distant from the feeding port (111) is less than the pressure loss of the slurry flowing to the coating port (1410) close to the feeding port (111), thereby improving the uniformity of slurry coating in the coating process.

Description

Coating die and electrode coating device

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202321692439.6, 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 a first aspect, some embodiments of the present application provide a coating die head, comprising a feed inlet, a first flow balancing chamber, a flow channel, and multiple coating ports. The first flow balancing chamber extends along a first direction and communicates with the feed inlet. The multiple coating ports are spaced apart along the first direction. The flow channel is used to connect the first flow balancing chamber and the multiple coating ports. The minimum cross-sectional area of ​​the flow channel between the multiple coating ports and the first flow balancing chamber increases in a direction from a coating port closer to the feed inlet to a coating port farther from the feed inlet.

[0009] Since the minimum cross-sectional area of ​​the flow channel between the multiple coating ports and the first flow equalization cavity tends to increase successively along the direction from the coating port close to the feed port to the coating port far away from the feed port, the pressure lost by the slurry flowing to the coating port far 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, which is beneficial to increasing the pressure of the slurry at the coating port far 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, 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 minimum length of the flow channel between the multiple coating ports and the first flow equalization cavity tends to decrease successively along the direction from the coating port close to the feed port to the coating port away from the feed port, so that the distance traveled by the slurry flowing to the coating port away from the feed port is smaller than the distance traveled by the slurry flowing to the coating port close to the feed port, thereby making the pressure lost by the slurry flowing to the coating port away from the feed port during the flow process smaller than the pressure lost by the slurry flowing to the coating port close to the feed port during the flow process.

[0011] According to some embodiments of the present application, the coating die includes a first die, a second die and a pressure strip. One of the first die and the second die is provided with a first cavity and a feed port connected to the first cavity, and the other 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.

[0012] According to some embodiments of the present application, the coating die head includes a first side, a second side, and a third side. The second side and the third side are spaced relative to each other in a second direction. The first side is connected between the second and third sides. A flow channel is formed between the first side and the inner wall of the first cavity. A first flow equalizing cavity is formed between the second side and the inner wall of the first cavity. The second direction is perpendicular to the first direction. By forming a flow channel between the first side and the inner wall of the first cavity, a first flow equalizing cavity is formed between the second side and the inner wall of the first cavity, so that the flow channel and the first flow equalizing cavity are smoothly connected.

[0013] 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 minimum distance between the second side surface and the inner wall surface of the first cavity tends to increase from the coating port close to the feed port to the coating port away from the feed port, so that along the direction of the coating port in the first direction away from the feed port, the minimum cross-sectional area of ​​the flow channel used to connect the coating port and the first flow equalizing cavity continues to increase, so that the minimum cross-sectional area of ​​the flow channel between the coating port close to the feed port and the first flow equalizing cavity is smaller than the minimum cross-sectional area of ​​the flow channel between the coating port away from the feed port and the first flow equalizing cavity.

[0014] According to the coating die provided in some embodiments of the present application, the minimum distance between the second side surface and the inner wall surface of the first cavity ranges from 1 mm to 10 mm.

[0015] According to the coating die provided in some embodiments of the present application, the distance between the second side and the third side tends to decrease from the coating port close to the feed port to the coating port away from the feed port, so that along the direction from the coating port in the first direction away from the feed port, the shortest part of the flow channel used to connect the coating port and the first flow equalizing cavity is continuously shortened, 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 distance between the second side surface and the third side surface ranges from 3 mm to 25 mm.

[0017] 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.

[0018] According to the coating die provided in some embodiments of the present application, the coating die 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.

[0019] According to the coating die provided in some embodiments of the present application, one of the first die and the second die is provided with a second cavity, and the other covers the second cavity to form a second flow equalization cavity. The second flow equalization cavity is connected to multiple coating ports. 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.

[0020] 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.

[0021] 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.

[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 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 cross-sectional areas of the flow channels between the plurality of coating ports and the first flow balancing chamber are arranged in a direction increasing in sequence from the coating port close to the feed port to the coating port far from the feed port, the pressure lost by the slurry flowing to the coating port far 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, which is conducive to increasing the pressure of the slurry at the coating port far from the feed port, balancing the pressure of the slurry at the plurality of coating ports, and 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 point B in FIG1 ;

[0030] FIG4 is a cross-sectional view of a flow channel of a coating die provided in some embodiments of the present application;

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

[0032] FIG6 is a schematic structural diagram of a first die head provided in some embodiments of the present application;

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

[0034] FIG8 is a schematic structural diagram of a coating die provided in some embodiments of the present application;

[0035] FIG9 is an enlarged view of point C in FIG8 .

[0036] The accompanying drawings in the specific implementation manner are as follows:

[0037] 11. First die head; 111. Feed port; 112. First cavity; 1121. Inner wall surface; 11210. First flow-distributing cavity; 11220. Flow channel; 113. Second cavity; 11310. Second flow-distributing cavity; 12. Second die head; 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; 16. First adjusting rod; 17. Second adjusting rod; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Coating is an essential process in battery production. The coating process has a crucial impact on battery quality and is a key process that directly affects various performance indicators such as battery safety, capacity, and lifespan. Coating is a method of applying a polymer paste, molten polymer, or polymer melt onto paper, cloth, or plastic film to produce a composite material (film). In the electrode coating process, a coating die applies the slurry to the surface of the electrode to impart good electrical properties.

[0046] 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.

[0047] 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, 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. 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 far from the feed port and the first flow balancing chamber, the pressure lost by the slurry flowing to the coating port far 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 far 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, thereby improving the uniformity of the slurry coating in the coating process.

[0048] 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.

[0049] 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.

[0050] As shown in Figure 1, some embodiments of the present application provide a coating die head, as shown in Figures 2 to 3, the coating die head includes 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 and is connected to the feed port 111, the plurality of coating ports 1410 are arranged at intervals along the first direction, 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 4, along the direction from the coating port 1410 close to the feed port 111 to the coating port 1410 away from the feed port 111, the minimum cross-sectional area of ​​the flow channel 11220 between the plurality of coating ports 1410 and the first flow equalizing chamber 11210 tends to increase successively.

[0051] 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.

[0052] The feed port 111 may be an opening structure provided on the coating die head, which is used to allow the slurry to pass into the coating die head. The first flow equalization cavity 11210 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 communicates with the feed port 111, so that the slurry flowing in from the feed port 111 can be distributed and temporarily stored in the coating die head 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 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.

[0053] 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.

[0054] The flow channel 11220 may be a structure provided in the coating die head 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. Along the direction from the coating port 1410 close to the feed port 111 to the coating port 1410 far from the feed port 111, the minimum cross-sectional area of ​​the flow channel 11220 between the plurality of coating ports 1410 and the first flow-equalizing cavity 11210 tends to increase successively. It may be that the minimum cross-sectional area 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 with the portion in the first flow-equalizing cavity 11210 is smaller than the minimum cross-sectional area of ​​the flow channel 11220 used to connect the coating port 1410 far from the feed port 111 among the plurality of coating ports 1410 1410 and the minimum cross-sectional area 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.

[0055] Among them, the cross-sectional area can be the area of ​​the cross section in the flow channel 11220 that is perpendicular to the extension direction of the flow channel 11220, that is, the cross-sectional area when the slurry flows in the flow channel 11220. The larger the cross-sectional area of ​​the flow channel 11220, the smaller the pressure loss when the slurry flows in the flow channel 11220.

[0056] Illustratively, the plurality of coating ports 1410 are spaced apart in the first direction X of the coating die head, the feed port 111 is connected to the middle portion of the first flow balancing chamber 11210 extending 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 minimum cross-sectional area of ​​the flow channel 11220 between the plurality of coating ports 1410 located on both sides of the feed port 111 and the first flow balancing chamber 11210 increases in a direction away from the feed port 111, the pressure loss of the slurry flowing through the flow channel 11220 can be continuously reduced.

[0057] In some embodiments, the minimum lengths of the flow channels 11220 between the plurality of coating ports 1410 and the first flow equalizing cavity 11210 decrease in sequence from the coating port 1410 close to the feed port 111 to the coating port 1410 away from the feed port 111 .

[0058] Along the direction of the coating port 1410 close to the feed port 111 to the coating port 1410 far away from the feed port 111, the minimum length of the flow channel 11220 between the multiple coating ports 1410 and the first flow equalizing cavity 11210 is gradually reduced. It can be that the minimum length of the flow channel 11220 used to connect the coating port 1410 close to the feed port 111 of the multiple coating ports 1410 with the first flow equalizing cavity 11210 is greater than the minimum length of the flow channel 11220 used to connect the coating port 1410 far away from the feed port 111 of the multiple 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.

[0059] Exemplarily, the plurality of coating ports 1410 are spaced apart in the first direction X of the coating die, the feed port 111 is connected to the middle portion of a first flow balancing chamber 11210 extending in the coating die along the first direction X, and the flow channel 11220 connects the first flow balancing chamber 11210 and the plurality of coating ports 1410. In the direction away from the feed port 111, the minimum length of the flow channel 11220 between the plurality of coating ports 1410 located on both sides of the feed port 111 and the first flow balancing chamber 11210 continuously decreases, so that the pressure loss caused by the slurry flowing through the flow channel 11220 can be continuously reduced.

[0060] In some embodiments, the coating die includes a first die 11, a second die 12 and a pressure strip 13. One of the first die 11 and the second die 12 is provided with a first cavity 112 and a feed port 111 connected to the first cavity 112, and the other 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, and 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.

[0061] The first die head 11, the second die head 12, and the pressure strip 13 can all be components of the coating die head. When connected to form the coating die head, they can also form structures such as the first flow equalization cavity 11210 and the flow channel 11220 in the coating die head. The first cavity 112 can be a groove-like structure opened in one of the first die head 11 and the second die head 12, 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-like component extending along the first direction X, which is connected to one of the first die head 11 and the second die head 12, and the other of 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 5, by spacing the pressure strip 13 from at least part of the inner wall of the first cavity 112, a first flow equalizing 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 equalizing cavity 11210 and the flow channel 11220 are connected to each other.

[0062] 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 6, 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.

[0063] 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. The first side 131 is connected between the second side 132 and the third side 133, and a flow channel 11220 is formed between the first side 131 and the inner wall surface 1121 of the first cavity 112. 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 is perpendicular to the first direction.

[0064] The first side surface 131, the second side surface 132, and the third side surface 133 can be different surfaces on the 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 can 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 is aligned with the side surface of the second die head 12, making the bead 13 more stable when 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 first flow equalization cavity 11210. The first side surface 131 can be the side surface of the bead 13 connected between the second side surface 132 and the third side surface 133. The gap between the first side surface 131 and the inner wall surface 1121 of the first cavity 112 forms the flow channel 11220 connecting the coating port 1410 and the first flow equalization cavity 11210.

[0065] In some embodiments, the cross-sectional area of ​​the first flow-equalizing 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-equalizing 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, and a larger gap is provided between the second side 132 and the inner wall 1121 of the semicircular first cavity 112. This larger gap between the second side 132 and the inner wall 1121 of the semicircular first cavity 112 enables storage of the slurry.

[0066] In some embodiments, the first cavity 112 and the bead 13 both extend along the first direction, and the minimum distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 increases from the coating port 1410 closer to the feed port 111 to the coating port 1410 farther from the feed port 111. By extending the first cavity 112 and the bead 13 along the first direction X, the first flow balancing cavity 11210 and the flow channel 11220 are continuously arranged along the first direction X.

[0067] The minimum distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 increases along the direction from the coating port 1410 close to the feed port 111 to the coating port 1410 away from the feed port 111. This means that along the direction in which the coating port 1410 is away from the feed port 111 in the first direction X, the minimum distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 increases continuously.

[0068] As the coating port 1410 moves away from the feed port 111 in the first direction X, the minimum cross-sectional area of ​​the flow channel 11220 used to connect the coating port 1410 and the first flow equalizing cavity 11210 continues to shorten, so that the minimum cross-sectional area of ​​the flow channel 11220 between the coating port 1410 close to the feed port 111 and the first flow equalizing cavity 11210 is smaller than the minimum cross-sectional area of ​​the flow channel 11220 between the coating port 1410 away from the feed port 111 and the first flow equalizing cavity 11210.

[0069] 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.

[0070] For example, the minimum distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 is located on the side of the first die head 11 facing the second die head 12 and is arranged along the third direction Z, and the third direction Z is perpendicular to the first direction X. The distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 in the third direction Z is set as follows: y1 = a1x1 2 +b1x1+c1 (1)

[0071] Wherein, y1 is the distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 in the third direction Z, x1 is the distance between the coating port 1410 and the feed port 111 in the first direction X, and a1, b1 and c1 are all constants obtained based on simulation and field verification. For example, the value range of a1 can be 0.000001 to 0.00003, the value range of b1 can be -0.00001 to -0.0003, and the value range of c1 can be 0 to 10. In some embodiments, the value range of a1 can be 0.000005 to 0.00002, the value range of b1 can be -0.00005 to -0.0002, and the value range of c1 can be 0 to 5. For example, the value of a1 can be 0.00001, the value of b1 can be 0.0001, and the value of c1 can be 2.

[0072] In some embodiments, the distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 in the third direction Z can also be set as a linear, exponential, logarithmic or power function. Those skilled in the art can set the distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 in the third direction Z according to actual conditions.

[0073] For example, when the slurry formula changes, the coating die head can improve the uniformity of the slurry coating by replacing the pressure strip 13 with a different arrangement of the spacing between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 in the third direction Z.

[0074] In some embodiments, the minimum distance between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 is in a range of 1 mm to 10 mm.

[0075] By setting the minimum spacing between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 to a range of 1 mm to 10 mm, the minimum cross-sectional area of ​​the flow channel 11220 between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 is within an appropriate range, so that the flow channel 11220 can provide an appropriate and sufficient amount of slurry to the coating port 1410. For example, the minimum spacing between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 can be set to a range of 2 mm to 8 mm, which helps ensure that the slurry provided by the flow channel 11220 meets the requirements of the coating port 1410.

[0076] In some embodiments, the distance between the second side surface 132 and the third side surface 133 decreases continuously from the coating port 1410 close to the feed port 111 to the coating port 1410 away from the feed port 111 .

[0077] The distance between the second side 132 and the third side 133 continuously decreases along the direction from the coating port 1410 close to the feed port 111 to the coating port 1410 away from the feed port 111, which can mean that along the direction from the coating port 1410 in the first direction X 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 from the coating port 1410 in the first direction X 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 away from the feed port 111 and the first flow equalizing cavity 11210.

[0078] For example, the layering strip 13 extending along the first direction X can be composed of multiple sections spliced ​​together, 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 choose the composition form of the layering strip 13 according to actual conditions.

[0079] 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: y2=a2x2 2 +b2x2+c2 (2)

[0080] Wherein, y2 is the spacing between the second side 132 and the third side 133 in the second direction Y, x2 is the distance between the coating port 1410 and the feed port 111 in the first direction X, and a2, b2 and c2 are all constants obtained based on simulation and field verification. For example, the value range of a2 can be -0.00003 to -0.00005, the value range of b2 can be 0.0001 to 0.0003, and the value range of c2 can be 5 to 30. In some embodiments, the value range of a2 can be -0.00001 to -0.00003, the value range of b2 can be 0.00005 to 0.0002, and the value range of c2 can be 10 to 25, for example, the value of a2 can be -0.00002, the value of b2 can be 0.0001, and the value of c2 can be 18.

[0081] In some embodiments, the spacing between the second side 132 and the third side 133 in the second direction Y can also be set as a linear, exponential, logarithmic or power function. Those skilled in the art can set the spacing between the second side 132 and the third side 133 in the second direction Y according to actual conditions.

[0082] 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.

[0083] In some embodiments, the distance between the second side surface 132 and the third side surface 133 ranges from 3 mm to 25 mm.

[0084] By setting the spacing between the second side 132 and the third side 133 to a range of 3 mm to 25 mm, the length of the flow channel 11220 between the second side 132 and the third side 133 is within an appropriate range, and the pressure loss of the slurry flowing through the flow channel 11220 is within a reasonable range. For example, setting the spacing between the second side 132 and the third side 133 to a range of 5 mm to 20 mm is conducive to ensuring that the length of the flow channel 11220 is within an appropriate range and the pressure loss of the slurry flowing through the flow channel 11220 is relatively low.

[0085] In some embodiments, the first side surface 131 is configured as an arc surface.

[0086] 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.

[0087] In some embodiments, as shown in Figure 7, the coating die also includes a gasket 14, which has 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.

[0088] 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 8 and 9, 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 equalization cavity 11210 can flow into the notches 141 and flow out to the outside world for coating.

[0089] 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.

[0090] 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 .

[0091] 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.

[0092] 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.

[0093] In some embodiments, one of the first die head 11 and the second die head 12 is provided with a second cavity 113 , and the other covers the second cavity 113 to form a second flow equalizing cavity 11310 , which is connected to a plurality of coating ports 1410 .

[0094] The second cavity 113 can be a groove-shaped structure opened by one of the first die head 11 and the second die head 12, and the other of the first die head 11 and the second die head 12 covers the second cavity 113, so that the second cavity 113 forms a second equal flow cavity 11310 connected to multiple coating ports 1410.

[0095] 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.

[0096] 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.

[0097] In some embodiments, as shown in Figure 8, the coating die also 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] According to some embodiments of the present application, the present application provides a coating die head, which 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 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, and the gasket 14 is clamped between the first die head 11 and the second cavity 113. Between the head 11 and the second die head 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, and 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, and the flow channel 11220 connects the first equalizing flow cavity 11210 with multiple coating ports 1410.

[0102] The second side surface 132 and the third side surface 133 in the pressure strip 13 are relatively spaced apart in the second direction Y. Since the spacing between the second side surface 132 and the third side surface 133 decreases continuously along the direction in which the coating port 1410 in the first direction X is away from the feed port 111, 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; the spacing between the second side surface 132 and the inner wall surface 1121 of the first cavity 112 is along the third direction Z in which the coating port 1410 is away from the feed port 111. The direction of the material port 111 continues to increase, so that the minimum cross-sectional area of ​​the flow channel 11220 between the coating port 1410 close to the feed port 111 and the first flow equalizing cavity 11210 is smaller than the minimum cross-sectional area 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 smaller 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.

[0103] 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.

[0104] 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.

[0105] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them. Although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, 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 description 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 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; Along the direction from the coating port close to the feed port to the coating port far away from the feed port, the minimum cross-sectional areas of the flow channels between the plurality of coating ports and the first flow equalizing cavity tend to increase successively.

2. The coating die head according to claim 1, wherein: Along the direction from the coating port close to the feed port to the coating port far away from the feed port, the minimum lengths of the flow channels between the plurality of coating ports and the first flow equalizing cavity tend to decrease successively.

3. The coating die head according to claim 2, wherein: The coating die head includes a first die head, a second die head and a pressure strip, one of the first die head and the second die head is provided with a first cavity and the feed port communicated with the first cavity, the other 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.

4. The coating die head according to claim 3, wherein: 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 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.

5. The coating die head according to claim 4, wherein: The first cavity and the pressure strip both extend along the first direction, and the minimum distance between the second side surface and the inner wall surface of the first cavity tends to increase from the coating port close to the feed port to the coating port away from the feed port.

6. The coating die head according to claim 5, wherein: The minimum distance between the second side surface and the inner wall surface of the first cavity is in a range of 1 mm to 10 mm.

7. The coating die head according to any one of claims 4 to 6, wherein: The distance between the second side surface and the third side surface tends to decrease along a direction from the coating port close to the feed port to the coating port far away from the feed port.

8. The coating die head according to claim 7, wherein: The distance between the second side surface and the third side surface ranges from 3 mm to 25 mm.

9. The coating die head according to any one of claims 4 to 8, wherein: The first side surface is configured as an arc surface.

10. The coating die head according to any one of claims 3 to 9, wherein: The coating die head further comprises a gasket, the gasket is provided with a plurality of notches at intervals along the first direction, the gasket is sandwiched between the first die head and the second die head, and the plurality of notches are all connected to the flow channel to form the coating port.

11. The coating die head according to any one of claims 3 to 10, wherein: One of the first die head and the second die head is provided with a second cavity, and the other one 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.

12. The coating die according to any one of claims 3 to 11, 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.

13. The coating die according to claim 12, 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.

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

Images