Coating device and pole piece production system

Abstract

The utility model provides a coating device and a pole piece production system. The coating device comprises a coating die head and an auxiliary unit. The coating die head is used for coating the surface of a base material with a coating. The auxiliary unit comprises a connecting piece and a discharging end which are connected with each other, the discharging end is detachably connected with the coating die head through the connecting piece, the discharging end is used for applying a functional substance to a coating so as to apply a functional layer to the surface of the coating and / or change the thickness of the coating, and the discharging end is movably arranged relative to the coating die head. The production yield of the coating process can be improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a coating device and a pole piece production system. Background Art

[0002] 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 electric tools, etc.

[0003] 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 production yield of the coating process has always been an important research direction for those skilled in the art. Utility Model Content

[0004] In view of the above problems, the present application provides a coating device and an electrode production system, which can improve the production yield of the coating process.

[0005] On the one hand, an embodiment of the present application provides a coating device, which includes a coating die and an auxiliary unit. The coating die is used to apply a coating on the surface of a substrate. The auxiliary unit includes a connecting piece and a discharge end connected to each other, the discharge end is detachably connected to the coating die through the connecting piece, the discharge end is used to apply a functional substance to the coating to apply a functional layer to the coating surface and / or change the thickness of the coating, and the discharge end is movably arranged relative to the coating die.

[0006] In the above scheme, the coating die head can apply a coating to the surface of the substrate, and the auxiliary unit can apply a functional substance to the coating to apply a functional layer to the coating surface and / or change the thickness of the coating, thereby improving the performance of the coating and further improving the production yield of the electrode. The auxiliary unit can be disassembled, and the applied functional substance can be replaced by disassembling the auxiliary unit during mass production, which is beneficial to reduce the manufacturing cost of mass production. By adjusting the position of the discharge end, the coating area of ​​the discharge end can be adjusted more flexibly, and targeted adjustment of the coating can be achieved, which is beneficial to timely improve the local defective areas generated in the coating and improve the reliability of the electrode.

[0007] In some embodiments, the coating device further includes a back roller, the back roller and the coating die are spaced apart along a first direction, the auxiliary unit is arranged on one side of the coating die along a second direction, and the direction in which the coating die points to the auxiliary unit is the conveying direction of the substrate.

[0008] In the above scheme, it is helpful to reduce the difficulty of arranging the auxiliary unit, simplify the difficulty of installing the auxiliary unit, and improve the efficiency of the auxiliary unit.

[0009] In some embodiments, the discharge end is disposed opposite to the backing roller. The discharge end is used to apply the first functional substance to the coating to form a functional layer on the surface of the coating.

[0010] In the above scheme, it is beneficial for the discharge end to apply functional substances to the coated coating to improve the efficiency of the discharge end.

[0011] In some embodiments, the first functional material includes one or more combinations of organic particles, carbon fibers, lithium supplements, binders, and plasticizers.

[0012] In the above scheme, different functional substances are applied to the coating to adjust the physical or chemical properties of the coating, for example, to increase the ion content, increase the viscosity of the coating and the substrate or the diaphragm, and adjust the plasticity of the coating. This is conducive to increasing the various characteristics of the coating to improve the application range of the pole piece.

[0013] In some embodiments, the minimum distance between the discharge end and the backing roller is d, 1 cm≤d≤100 cm. Alternatively, 2 cm≤d≤50 cm.

[0014] In the above scheme, the distance between the backing roller and the discharge end is controlled to balance the size of the coating area and the coating efficiency, and the risk of damaging the coating due to excessively fast coating speed of the applied functional substance can also be reduced.

[0015] In some embodiments, the discharge end includes a discharge port, the gap between the coating die and the backing roller is arranged opposite to the discharge port along the second direction, and the discharge end is used to apply a second functional substance to the coating to change the thickness of the coating.

[0016] In the above scheme, the thickness of the formed coating is made thinner, and the coating thinning process is achieved, thereby reducing the thickness of the formed pole piece, reducing the space occupied by a single pole piece in the battery cell, and improving the energy density.

[0017] In some embodiments, the second functional substance includes one or more combinations of dry air, high-purity gas, inert gas, and organic gas.

[0018] In the above solution, by applying the second functional material to the gap, the thickness of the formed pole piece is reduced, and the risk of the second functional material damaging the coating can also be reduced. In addition, the flexible selection of materials can also reduce the production cost.

[0019] In some embodiments, the coating die head includes a flow channel and a coating port located at the end of the flow channel, the flow channel is disposed in the coating die head, and the angle between the tangent line of the rotation direction of the back roller and the corresponding area of ​​the coating port and the extension direction of the flow channel is α, 0°<α<90°. Optionally, 15°≤α≤60°.

[0020] In the above scheme, through the above arrangement, during the conveying process of the substrate, the slurry coated by the coating port can follow the movement of the substrate to form a coating on the substrate. By setting the angle, the coating speed of the coating port can be different from the conveying speed of the substrate, which can increase the coating area, thereby reducing the possibility of coating breakage due to speed difference and improving production yield.

[0021] In some embodiments, the connector and the coating die are rotatably connected.

[0022] In the above scheme, the connecting piece and the coating die head can rotate, which is beneficial to increase the rotation range of the discharge port and further increase the coating area of ​​the auxiliary unit.

[0023] In some embodiments, the connecting member and the discharge end are rotatably connected.

[0024] In the above scheme, it is helpful to reduce the difficulty of manufacturing the auxiliary unit and reduce the manufacturing cost of the auxiliary unit.

[0025] In some embodiments, the connecting member includes a main body and a recessed portion, the main body includes a first surface facing the discharge end, the recessed portion is recessed from the first surface into the main body, the discharge end includes a discharge channel and a rotating portion located on the outer surface of the discharge channel, and at least part of the rotating portion is located in the recessed portion.

[0026] In the above scheme, by rotating the discharge channel, the coating angle and coating position of the discharge port can be adjusted more accurately, which is beneficial to improving the coating effect of the auxiliary unit, further improving the performance of the coating, and improving the production yield.

[0027] In some embodiments, the recess includes a limiting protrusion, the limiting protrusion is provided by a side wall surface of the recess protruding from the side wall surface, and the limiting protrusion is provided close to the first surface.

[0028] In the above solution, the limiting protrusion can reduce the possibility of separation between the connecting portion and the recessed portion, improve the connection reliability, and further improve the reliability of the auxiliary unit and the production yield.

[0029] In some embodiments, the coating die includes a first die, a second die and a flow channel located between the first die and the second die. The direction of the second die pointing to the first die is parallel to the conveying direction of the relative area of ​​the pole piece and the coating die. The connecting piece and the first die are detachably connected.

[0030] In the above scheme, by detachably connecting the connecting piece and the first die head, the discharge end is located on the side coated with the coating, which is beneficial for the auxiliary unit to apply functional substances to the coating, reduces the assembly difficulty between the auxiliary unit and the coating die head, and reduces production costs.

[0031] In a second aspect, an embodiment of the present application provides a pole piece production system, comprising a coating device in any of the aforementioned embodiments.

[0032] 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

[0033] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 is a schematic cross-sectional structure diagram of a coating device provided in an embodiment of the present application;

[0035] Figure 2 is a schematic cross-sectional structure diagram of another coating device provided in an embodiment of the present application;

[0036] Figure 3 is a schematic cross-sectional structure diagram of another coating device provided in an embodiment of the present application;

[0037] Figure 4 yes Figure 3 Schematic diagram of the enlarged structure of the middle Q;

[0038] Figure 5 is a schematic cross-sectional structure diagram of another coating device provided in an embodiment of the present application;

[0039] Figure 6 is a schematic cross-sectional structure diagram of another coating device provided in an embodiment of the present application;

[0040] Figure 7 is a schematic cross-sectional structure diagram of another coating device provided in an embodiment of the present application;

[0041] Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of R.

[0042] In the attached figure:

[0043] Marking Description

[0044] 10. coating die; 11. flow channel; 12. coating port; 13. first die; 14. second die;

[0045] 20. Auxiliary unit; 21. Connecting piece; 211. Main body; 212. Concave portion; 213. Position limiting protrusion; 22. Discharging end; 221. Discharging port; 222. Discharging channel; 223. Rotating portion;

[0046] 30. Back roller;

[0047] S1, first surface; P1, substrate; P2, coating; 31, sub-back roller;

[0048] X, first direction; Y, second direction; A1, conveying direction; A2, output direction. DETAILED DESCRIPTION

[0049] The following embodiments of the technical solution of the present application are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and are therefore only used as examples, and cannot be used to limit the scope of protection of the present application.

[0050] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned figure descriptions and any variations thereof are intended to cover non-exclusive inclusions.

[0051] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0052] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0053] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0054] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0055] 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 referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0056] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0057] At present, judging from the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as military equipment and aerospace and other fields.

[0058] Coating is an essential process in the battery production process. The coating process has a very important impact on the quality of the battery and is a key process that directly affects the safety, capacity, life and other performance indicators of the battery. Coating is a method of coating a paste polymer, a molten polymer or a polymer melt on paper, cloth or plastic film to obtain a composite material (film). In the coating process of the pole piece, the coating die coats the slurry on the surface of the current collector to give the pole piece good electrical properties.

[0059] At present, after the coating die coats the substrate, the physical properties of the coating, such as the ion content and viscosity, are determined solely by the slurry extruded by the coating die, which makes the coating function of the coating die single. The physical properties of the coating cannot be further adjusted after coating. When there is a problem with the slurry itself or the formed coating, the electrical properties of the electrode will be reduced or even unusable.

[0060] Based on the above technical problems, the present application provides a technical solution, in which an auxiliary unit can apply functional substances to the coating to apply a functional layer to the coating surface and / or change the thickness of the coating, thereby improving the production yield of the electrode. The auxiliary unit and the coating die head are detachably connected, which is conducive to replacing the auxiliary unit during the production process of the electrode and more flexible adjustment of the physical properties of the coating. The discharge end of the auxiliary unit can be moved to adjust the area and coating angle of the discharge end applied to the coating, so that the flexibility of adjusting the application of functional substances can be improved during the production process of the electrode.

[0061] The coating die head disclosed in the embodiment 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 a composite material (film), thereby obtaining a composite material (film) with certain properties.

[0062] The technical solutions of the coating device and the electrode production system provided in the specific implementation manner of the present application are further explained below.

[0063] Figure 1 It is a schematic diagram of the cross-sectional structure of a coating device provided in an embodiment of the present application. Figure 2 It is a schematic diagram of the cross-sectional structure of another coating device provided in an embodiment of the present application.

[0064] See also Figure 1 and Figure 2 The embodiment of the present application provides a coating device, which includes a coating die 10 and an auxiliary unit 20. The coating die 10 is used to apply a coating layer P2 on the surface of a substrate P1. The auxiliary unit 20 includes a connecting piece 21 and a discharge end 22 connected to each other, and the discharge end 22 is detachably connected to the coating die 10 through the connecting piece 21. The discharge end 22 is used to apply a functional substance to the coating layer P2 to apply a functional layer to the surface of the coating layer P2 and / or change the thickness of the coating layer P2. The discharge end 22 is movably arranged relative to the coating die 10.

[0065] Alternatively, the substrate P1 may include a current collector. Alternatively, the coating P2 may include an active material layer.

[0066] Exemplarily, the coating device can be a component in a generating system that coats the slurry on the surface of the current collector during the coating process. After the slurry passes into the coating die 10, it is simultaneously coated on multiple locations of the substrate P1 under the action of the coating die 10 to achieve efficient coating on the substrate P1.

[0067] Optionally, the number of the coating die head 10 may include one or more.

[0068] Optionally, the number of auxiliary units 20 may be the same as the number of coating dies 10, or may be different.

[0069] For example, Figure 1 As shown, one coating die head 10 corresponds to one auxiliary unit 20. The coating area of ​​one coating die head 10 is the same as the coating area of ​​the auxiliary unit 20. Alternatively, multiple coating die heads 10 correspond to one auxiliary unit 20, and the coating areas of multiple coating die heads 10 are the same as the coating area of ​​one auxiliary unit 20. Alternatively, as Figure 2 As shown, one coating die head 10 corresponds to a plurality of auxiliary units 20 .

[0070] The auxiliary unit 20 includes a connecting member 21 and a discharging end 22 connected to each other. The connecting member 21 may be a rod with a preset length and a preset angle. Alternatively, the connecting member 21 may also be a plate, and a through hole is provided on the connecting member 21, and the discharging end 22 is inserted into the through hole. Of course, the embodiment of the present application does not impose any special restrictions on this, and it is sufficient to ensure that the connecting member 21 and the discharging end 22 are connected.

[0071] The discharge end 22 is detachably connected to the coating die 10 via the connector 21. In other words, the connector 21 is detachably connected to the coating die 10. For example, the connector 21 and the coating die 10 can be connected by bolts, buckles, etc.

[0072] Optionally, the number of the connecting members 21 may include one or more. For example, the discharge end 22 is connected to the coating die 10 via a plurality of connecting members 21 .

[0073] Optionally, the discharge end 22 may include a nozzle, such as a circular nozzle, a slit nozzle, a trapezoidal nozzle or a nozzle of other shapes. Optionally, the shape of the discharge end 22 may be tapered, for example, it may be tapered along the discharge direction to improve the coating speed and accuracy. Of course, it may be tapered in the direction opposite to the discharge direction to increase the coating area.

[0074] The discharge end 22 is used to apply functional substances to the coating P2. Here, "applying to the coating P2" means that the applied functional substances can be applied to the surface of the coated coating P2, or can be applied to the coating P2 being applied. The "functional substances" here can include one or more combinations of solid materials, liquid materials and gaseous materials. The discharge end 22 can have a discharge port 221, and the discharge port 221 can apply the functional substances to the coating P2. The functional substances applied to the coating P2 by the discharge end 22 can only adhere to the surface of the coating P2 to form a functional layer, and of course, can also be immersed in the coating P2. Alternatively, the functional substances applied by the discharge end 22 can change the thickness of the coating, for example, reduce the thickness of the coating.

[0075] Optionally, the number of the discharge end 22 may include one or more.

[0076] Exemplarily, the connector 21 is connected to a plurality of discharge ends 22, and the functional substances applied to each discharge end 22 may be the same to improve the thickness uniformity of the functional layer. Of course, they may also be different, and applying different functional substances to different discharge ends 22 may improve various physical or chemical properties of the coating P2, such as viscosity, ion content or other properties.

[0077] The discharge end 22 is movably arranged relative to the coating die 10, and the "movable" here means that the discharge end 22 can approach or move away from the coating die 10 in a single direction; or move in a single direction; or, the discharge end 22 rotates about a preset axis, and the preset axis can be the connection between the coating die 10 and the connecting piece 21. Of course, the preset axis can also be the connection between the discharge end 22 and the connecting piece 21.

[0078] In the coating device provided in the embodiment of the present application, the coating die 10 can coat the coating P2 on the surface of the substrate P1, and the auxiliary unit 20 can apply a functional substance to the coating P2 to apply a functional layer to the surface of the coating P2 and / or change the thickness of the coating P2, thereby improving the performance of the coating P2, and then improving the production yield of the electrode. The auxiliary unit 20 can be disassembled, and the applied functional substance can be replaced by disassembling the auxiliary unit 20 during the mass production process, which is beneficial to reduce the manufacturing cost of mass production. By adjusting the position of the discharge end 22, the coating area of ​​the discharge end 22 can be adjusted more flexibly, and targeted adjustment of the coating P2 can be achieved, which is beneficial to timely improve the local defect area generated in the coating P2 and improve the reliability of the electrode.

[0079] Figure 3 It is a schematic diagram of the cross-sectional structure of another coating device provided in an embodiment of the present application.

[0080] In some optional embodiments, see Figure 1 and Figure 3 The coating device also includes a back roller 30, the back roller 30 and the coating die head 10 are arranged at intervals along the first direction X, the auxiliary unit 20 is arranged on one side of the coating die head 10 along the second direction Y, and the direction in which the coating die head 10 points to the auxiliary unit 20 is the conveying direction A1 of the substrate P1.

[0081] The back roller 30 can be used to convey the substrate P1. The rotation of the back roller 30 can drive the substrate P1 to move in a single direction or change from one direction to another direction. Driven by the back roller 30, the material sprayed by the coating die 10 and the auxiliary unit 20 can be coated on the substrate P1, thereby forming a coating P2 on the surface of the substrate P1. The embodiment of the present application takes the example that the back roller 30 can drive the substrate P1 to move from one direction to another. Exemplarily, the direction in which the substrate P1 is conveyed from the conveying device to the back roller 30 can be the conveying direction A1, and the direction in which the substrate P1 leaves the back roller 30 after the coating P2 is coated on the back roller 30 can be the output direction A2, and the conveying direction A1 and the output direction A2 intersect. Optionally, the conveying direction A1 and the output direction A2 can be set vertically.

[0082] The direction in which the coating die 10 points to the auxiliary unit 20 is the conveying direction A1 of the substrate P1. In other words, the coating die 10 first coats the surface of the substrate P1 with the coating P2, and the auxiliary unit 20 and the coated coating P2 area are correspondingly arranged. The auxiliary unit 20 and the coated coating P2 area can be arranged at intervals along the first direction X. Of course, the auxiliary unit 20 and the coated coating P2 area can be arranged at intervals in other directions.

[0083] The backing roller 30 and the coating die head 10 are spaced apart along the first direction X. The coating die head 10 has a coating port 12. The coating port 12 can coat the substrate P1 with the slurry to form the coating layer P2. The backing roller 30 can be spaced apart from the coating port 12 along the first direction X. For example, the projection of the coating port 12 along the first direction X falls within the projection of the backing roller 30 along the first direction X.

[0084] Of course, the back roller 30 may also include two sub-back rollers 31, which are spaced apart along the second direction Y, and the direction from the first sub-back roller 31 to the second sub-back roller 31 is parallel to the conveying direction A1. The substrate P1 is changed from the conveying direction A1 to the output direction A2 by the rotation of the second sub-back roller 31. There is a gap between the first sub-back roller 31 and the second sub-back roller 31, and the projection of the coating port 12 along the first direction X can fall on the substrate P1 area corresponding to the gap.

[0085] Optionally, the first direction X can be parallel to the gravity direction, and the coating die head 10 can be located on one side of the back roller 30 in the direction opposite to the gravity direction. Of course, the first direction X can also intersect with the gravity direction. Optionally, the first direction X can also intersect with the horizontal direction.

[0086] The above-mentioned configuration of the embodiment of the present application is helpful to reduce the difficulty of arranging the auxiliary unit 20 , simplify the difficulty of installing the auxiliary unit 20 , and improve the efficiency of the auxiliary unit 20 .

[0087] In some optional embodiments, see Figure 1 and Figure 3 The discharge end 22 is arranged opposite to the backing roller 30. The discharge end 22 is used to apply the first functional substance to the coating layer P2 so as to form a functional layer on the surface of the coating layer P2.

[0088] The discharge end 22 and the back roller 30 are arranged opposite to each other. In other words, the discharge end 22 can be arranged opposite to the area on the substrate P1 where the coating P2 is applied, so that the discharge end 22 can apply functional substances to the applied coating P2 to improve the efficiency of the discharge end 22.

[0089] In some optional embodiments, the first functional material includes one or more combinations of organic particles, carbon fibers, lithium supplements, binders, and plasticizers.

[0090] In these optional embodiments, different functional substances are applied to the coating P2 to adjust different physical or chemical properties of the coating P2, for example, to increase the ion content, to increase the viscosity of the coating P2 and the substrate P1 or the diaphragm, and to adjust the plasticity of the coating P2. This is conducive to increasing the various characteristics of the coating P2 to improve the application range of the pole piece.

[0091] Figure 4 yes Figure 3 Schematic diagram of the amplified structure of medium Q.

[0092] In some optional embodiments, see Figure 3 and Figure 4 The minimum distance between the discharge end 22 and the backing roller 30 is d, 1cm≤d≤100cm. Optionally, 2cm≤d≤50cm.

[0093] Optionally, the minimum distance between the discharge end 22 and the backing roller 30 may be 1 cm, 2 cm, 5 cm, 10 cm, 25 cm, 50 cm, 75 cm or 100 cm.

[0094] Optionally, the coating area is controlled by the distance between the discharge end 22 and the back roller 30. Of course, the coating area can also be controlled by the distance between the discharge end 22 and the back roller 30 and the coating angle of the discharge end 22. For example, the discharge end 22 is a nozzle of a tapered type in the direction opposite to the coating direction, and the coating angle of the discharge end 22 can be θ, 25°≤θ≤90°. For example, the coating angle of the discharge end 22 is 25°, 30°, 45°, 60°, 75° or 90°.

[0095] In these optional embodiments, the distance between the backing roller 30 and the discharge end 22 is controlled to balance the size of the coating area and the coating efficiency, and the risk of damaging the coating layer P2 due to excessively fast coating speed of the applied functional substance can be reduced.

[0096] Figure 5It is a schematic diagram of the cross-sectional structure of another coating device provided in an embodiment of the present application.

[0097] In some optional embodiments, see Figure 5 The discharge end 22 includes a discharge port 221. The gap between the coating die 10 and the back roller 30 is arranged opposite to the discharge port 221 along the second direction Y. The discharge end 22 is used to apply a second functional substance to the coating to change the thickness of the coating.

[0098] The discharge port 221 can be an outlet for applying functional substances. The gap between the coating die 10 and the back roller 30 is the gap used by the coating die 10 to apply the slurry. The slurry and the substrate P1 are in contact at this gap, and a coating P2 is formed on the surface of the substrate as the substrate moves. The discharge port 221 and the gap are arranged relative to each other along the second direction Y. The second functional substance applied by the discharge port 221 can act on the slurry when the slurry and the substrate P1 just come into contact, so that the thickness of the formed coating P2 becomes thinner, and the coating P2 is thinned, thereby reducing the thickness of the formed pole piece, reducing the space occupied by a single pole piece in the battery cell, and improving the energy density.

[0099] Optionally, the discharge port 221 and the coating die head 10 are arranged at intervals along the conveying direction A1, and the direction in which the gap between the discharge port 221 and the backing roller 30 points to the discharge port 221 may be parallel to the conveying direction A1.

[0100] Optionally, the shape of the discharge end 22 may be tapered along the coating direction, thereby reducing the possibility of affecting the coated coating layer P2 while applying the second functional substance to the slurry in the gap.

[0101] Alternatively, in some other embodiments, a bracket may be provided on the production line, and the auxiliary unit 20 and the bracket may be connected to achieve application of the second functional substance to the gap.

[0102] In some optional embodiments, the second functional substance includes one or more combinations of dry air, high-purity gas, inert gas and organic gas.

[0103] In these optional embodiments, by applying the second functional material to the gap, the thickness of the formed pole piece is reduced, and the risk of the second functional material damaging the coating P2 can also be reduced. In addition, the flexible selection of materials can also reduce the production cost.

[0104] Figure 6 It is a schematic diagram of the cross-sectional structure of another coating device provided in an embodiment of the present application.

[0105] In some optional embodiments, see Figure 6The coating die head 10 includes a flow channel 11 and a coating port 12 at the end of the flow channel 11. The flow channel 11 is disposed in the coating die head 10. The angle between the tangent line of the rotation direction of the back roller 30 and the corresponding area of ​​the coating port 12 and the extension direction of the flow channel 11 is α, 0°<α<90°. Optionally, 15°≤α≤60°.

[0106] The coating die 10 includes a flow channel 11 and a coating port 12. The slurry in the external storage tank can flow to the coating port 12 via the flow channel 11, and then be coated on the surface of the substrate P1 via the coating port 12. Optionally, the coating die 10 may include multiple branch flow channels and a main flow channel. The slurry in the external storage tank can be diverted to multiple branch flow channels via the main flow channel. Each end of the branch flow channel may be provided with a branch coating port, and multiple branch coating ports form the coating port 12. Of course, the coating die 10 may also include an outflow flow channel and a coating port 12. In the embodiment of the present application, the extension direction of the flow channel 11 is the extension direction of the branch flow channel and / or the extension direction of the outflow flow channel.

[0107] In the embodiment of the present application, the area corresponding to the back roller 30 and the coating port 12 refers to the area where the coating port 12 is coated on the substrate P1, or the overlapping area of ​​the projection of the coating port 12 along the first direction X and the projection of the back roller 30 along the first direction X. In this area, the angle between the tangent line in the rotation direction of the back roller 30 and the extension direction of the flow channel 11 can also be the angle between the conveying direction A1 of the substrate P1 and the extension direction of the flow channel 11.

[0108] Optionally, the angle between the tangent of the rotation direction of the back roller 30 and the corresponding area of ​​the coating port 12 and the extension direction of the flow channel 11 includes 1°, 5°, 10°, 15°, 30°, 45°, 60°, 75°, 80° or 85°.

[0109] In these optional embodiments, through the above settings, during the conveying process of the substrate P1, the slurry coated by the coating port 12 can follow the movement of the substrate P1 to form a coating layer P2 on the substrate P1. By setting the angle, the coating speed of the coating port 12 can be different from the conveying speed of the substrate P1, which can increase the coating area, thereby reducing the possibility of the coating layer P2 breaking due to the speed difference and improving the production yield.

[0110] In some optional embodiments, see Figure 6 , the connecting piece 21 and the coating die head 10 are rotatably connected.

[0111] Optionally, the connecting member 21 and the coating die head 10 may be rotatably connected by means of a universal joint, a rotary joint, or the like.

[0112] As an example, a groove may be provided on the coating die head 10, and a connecting ball head may be provided on the connecting member 21, and the connecting ball head and the groove may be detachably connected by plugging and unplugging. The connecting ball head may rotate within a preset angle range in the groove. Optionally, the connecting ball head may swing in a single direction, or rotate with the ball head as a base point.

[0113] In these optional embodiments, the connector 21 and the coating die head 10 can rotate, which is beneficial to increase the rotation range of the discharge port and further increase the coating area of ​​the auxiliary unit 20.

[0114] Figure 7 It is a schematic diagram of the cross-sectional structure of another coating device provided in an embodiment of the present application. Figure 8 yes Figure 7 Schematic diagram of the enlarged structure of R.

[0115] In some optional embodiments, see Figure 7 and Figure 8 , the connecting piece 21 and the discharge end 22 are rotatably connected.

[0116] Optionally, the connecting member 21 and the discharge end 22 may be rotatably connected by means of a universal joint, a rotary joint, or the like.

[0117] In some examples, the connection between the connector 21 and the discharge end 22 can be a rotatable connection. In other examples, the connector 21 includes a first connection portion and a second connection portion, the first connection portion and the second connection portion are rotatably connected, the first connection portion and the coating die head 10 are detachably connected, and the second connection portion and the discharge end 22 are connected. Optionally, the second connection portion and the discharge end 22 can be fixedly connected or detachably connected. For example, the second connection portion and the discharge end 22 are detachably connected, and the discharge end 22 can be made as a standard part, and the discharge end 22 can be replaced by disassembly to achieve the purpose of replacing different functional substances.

[0118] These optional embodiments are helpful to reduce the difficulty of manufacturing the auxiliary unit 20 and reduce the manufacturing cost of the auxiliary unit 20.

[0119] In some optional embodiments, see Figure 7 and Figure 8 The connecting member 21 includes a main body 211 and a recessed portion 212. The main body 211 includes a first surface S1 facing the discharge end 22. The recessed portion 212 is recessed from the first surface S1 into the main body 211. The discharge end 22 includes a discharge channel 222 and a rotating portion 223 located on the outer surface of the discharge channel 222. At least a portion of the rotating portion 223 is located in the recessed portion 212.

[0120] Optionally, the connecting member 21 includes a main body 211 and a recess 212. The main body 211 may include one or more combinations of a rod structure and a plate structure. The recess 212 may be recessed to a preset depth from the first surface S1 of the main body 211. Optionally, the recessed shape of the recess 212 includes a spherical shape, a hemispherical shape, a rectangular shape or a square shape. Of course, the shape of the recess 212 may also be other shapes. The embodiment of the present application does not impose any special restrictions on this. The following example uses the recessed shape of the recess 212 as a rectangle for illustration.

[0121] The functional substance may flow out of the discharge port through the discharge channel 222. Optionally, the number of the discharge channels 222 may include one or more. For example, one discharge channel 222 corresponds to one discharge port. Alternatively, multiple discharge channels 222 correspond to one discharge port. Further, the functional substances in at least part of the multiple discharge channels 222 may be different, and the different functional substances in the multiple discharge channels 222 may be fused at the discharge port or in a preset area of ​​the discharge channel 222 to form a specific functional substance, and then applied to the coating P2 via the discharge port.

[0122] In some examples, the shape of the rotating portion 223 can be matched with the shape of the recess 212. For example, the recessed shape of the recess 212 is rectangular. The rotating portion 223 can include a rotating ball head and a connecting rod. The rotating ball head is located in the recess 212. One end of the connecting rod is connected to the rotating ball head, and the other end is connected to the discharge channel 222.

[0123] Optionally, the discharge channel 222 and the rotating portion 223 may be an integrated structure. Of course, they may also be separate structures.

[0124] Exemplarily, the discharge channel 222 is provided with structures such as a slot and a magnet for realizing a detachable connection with the rotating part 223 .

[0125] In some examples, a portion of the rotating portion 223 is located in the recess 212 . In other examples, the entire rotating portion 223 is located in the recess 212 .

[0126] In these optional embodiments, by rotating the discharge channel 222, the coating angle and coating position of the discharge port can be adjusted more accurately, which is beneficial to improving the coating effect of the auxiliary unit 20, further improving the performance of the coating P2, and improving the production yield.

[0127] In some optional embodiments, see Figure 7 and Figure 8 The recess 212 includes a limiting protrusion 213 , and the limiting protrusion 213 is provided by a side wall surface of the recess 212 protruding from the side wall surface, and the limiting protrusion 213 is provided close to the first surface S1 .

[0128] Optionally, the limiting protrusion 213 can be arranged to protrude from the side wall surface in a single direction. Of course, the limiting protrusion 213 can be arranged to protrude from the side wall surface in two directions, so that the cross-sectional shape of the limiting protrusion 213 can be arc-shaped.

[0129] Optionally, the limiting protrusion 213 may be disposed along a side wall surface of the recess 212 , such that the limiting protrusion 213 surrounds the geometric center of the recess 212 .

[0130] Optionally, the number of the limiting protrusions 213 may include one or more.

[0131] In the embodiment of the present application, the limiting protrusion 213 is arranged close to the first surface S1, that is, the limiting protrusion 213 is arranged on the opening side of the recess 212 close to the recess 212, so that a limiting space is formed between the limiting protrusion 213 and the bottom wall of the recess 212, and the rotation amplitude of the connecting part in the limiting space will be affected by the limiting protrusion 213, and the limiting protrusion 213 can reduce the possibility of separation between the connecting part and the recess 212, thereby improving the connection reliability, thereby improving the reliability of the auxiliary unit 20, and improving the production yield.

[0132] In some optional embodiments, see Figure 6 The coating die 10 includes a first die 13, a second die 14 and a flow channel 11 located between the first die 13 and the second die 14. The direction of the second die 14 pointing to the first die 13 is parallel to the conveying direction A1 of the relative area between the pole piece and the coating die 10. The connecting piece 21 and the first die 13 are detachably connected.

[0133] Optionally, the first die head 13 and the second die head 14 may be an integral structure, or alternatively, may be a separate structure.

[0134] The conveying direction A1 of the relative area between the electrode piece and the coating die head 10 is the conveying direction A1 mentioned above, which will not be described in detail here.

[0135] Optionally, the direction in which the second die 14 points to the first die 13 is parallel to the conveying direction A1. In other words, the projection of the second die 14 along the first direction X falls on the substrate P1 and overlaps with the area on the substrate P1 that is not coated with the coating P2, and the projection of the first die 13 along the first direction X falls on the substrate P1 and overlaps with the area on the substrate P1 that is coated with the coating P2.

[0136] In these optional embodiments, by detachably connecting the connecting piece 21 and the first die head 13, the discharge end 22 is located on the side coated with the coating P2, which is beneficial for the auxiliary unit 20 to apply functional substances to the coating P2, reduces the difficulty of assembly between the auxiliary unit 20 and the coating die head 10, and reduces production costs.

[0137] In a second aspect, an embodiment of the present application provides a pole piece production system, comprising a coating device in any of the aforementioned embodiments.

[0138] It should be noted that the electrode production system provided in the embodiment of the present application has the beneficial effects of the coating device in any of the aforementioned embodiments. For specific details, please refer to the aforementioned description of the beneficial effects of the coating device, and the embodiment of the present application will not be repeated here.

[0139] According to some embodiments of the present application, please refer to Figure 1 as well as Figures 4 to 6 The coating device includes a coating die 10 and an auxiliary unit 20. The coating die 10 is used to coat a coating layer P2 on the surface of a substrate P1. The auxiliary unit 20 includes a connecting piece 21 and a discharge end 22 connected to each other. The discharge end 22 is detachably connected to the coating die 10 through the connecting piece 21. The discharge end 22 is used to apply a functional substance to the coating layer P2 to apply a functional layer to the surface of the coating layer P2 and / or change the thickness of the coating layer P2. The discharge end 22 is movably arranged relative to the coating die 10.

[0140] The coating device further includes a back roller 30, the back roller 30 and the coating die 10 are arranged at intervals along the first direction X, the auxiliary unit 20 and the coating die 10 are arranged side by side along the second direction Y, and the direction in which the coating die 10 points to the auxiliary unit 20 is the conveying direction A1 of the substrate P1. The discharge end 22 is arranged opposite to the back roller 30 to apply the first functional substance to the coated coating P2, thereby applying a functional layer to the coating surface. The discharge end 22 includes a discharge port 221, and the gap between the coating die 10 and the back roller 30 is arranged opposite to the discharge port 221 along the second direction Y. The discharge end 22 is used to apply the second functional substance to adjust the thickness of the coating P2 during the coating process, so that the thickness of the coating P2 after coating is reduced. The coating die head 10 includes a flow channel 11 and a coating port 12 at the end of the flow channel 11. The flow channel 11 is disposed in the coating die head 10. The angle between the tangent line of the rotation direction of the area corresponding to the back roller 30 and the coating port 12 and the extension direction of the flow channel 11 is α, 0°<α<90°. The connector 21 and the coating die head 10 are rotatably connected.

[0141] 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 replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate 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 device, characterized in that: include A coating die head is used to apply a coating on the surface of a substrate; The auxiliary unit includes a connecting piece and a discharge end connected to each other, wherein the discharge end is detachably connected to the coating die through the connecting piece, and the discharge end is used to apply a functional substance to the coating to apply a functional layer to the coating surface and / or change the thickness of the coating, and the discharge end is movably arranged relative to the coating die.

2. The coating device according to claim 1, characterized in that: It also includes a back roller, which is spaced apart from the coating die along a first direction, the auxiliary unit is arranged on one side of the coating die along a second direction, and the direction in which the coating die points to the auxiliary unit is the conveying direction of the substrate.

3. The coating device according to claim 2, characterized in that: The discharge end is arranged opposite to the backing roller, and the discharge end is used to apply a first functional substance to the coating so as to form a functional layer on the surface of the coating.

4. The coating device according to claim 3, characterized in that: The first functional substance is one of organic particles, carbon fibers, lithium supplements, binders and plasticizers.

5. The coating device according to claim 3, characterized in that: The minimum distance between the discharge end and the backing roller is d, 1cm≤d≤100cm.

6. The coating device according to claim 5, characterized in that: 2cm≤d≤50cm.

7. The coating device according to claim 2, characterized in that: The discharge end comprises a discharge port, the gap between the coating die head and the backing roller is arranged opposite to the discharge port along the second direction, and the discharge end is used to apply a second functional substance to the coating to change the thickness of the coating.

8. The coating device according to claim 7, characterized in that: The second functional substance is one of dry air, high-purity gas, inert gas and organic gas.

9. The coating device according to claim 7, characterized in that: The coating die head includes a flow channel and a coating port located at the end of the flow channel. The flow channel is arranged in the coating die head. The angle between the tangent of the rotation direction of the back roller and the corresponding area of ​​the coating port and the extension direction of the flow channel is α, 0°<α<90°.

10. The coating device according to claim 9, characterized in that: 15°≤α≤60°。 11. The coating device according to claim 1, characterized in that: The connecting piece and the coating die head are rotatably connected.

12. The coating device according to claim 1, characterized in that: The connecting piece and the discharging end are rotatably connected.

13. The coating device according to claim 12, characterized in that: The connecting member includes a main body and a recessed portion, the main body includes a first surface facing the discharge end, the recessed portion is recessed from the first surface into the main body, the discharge end includes a discharge channel and a rotating portion located on the outer surface of the discharge channel, and at least a portion of the rotating portion is located in the recessed portion.

14. The coating device according to claim 13, characterized in that: The recess includes a limiting protrusion, which is provided by a side wall surface of the recess and protrudes from the side wall surface, and the limiting protrusion is provided close to the first surface.

15. The coating device according to claim 1, characterized in that: The coating die includes a first die, a second die and a flow channel located between the first die and the second die. The direction of the second die pointing to the first die is parallel to the conveying direction of the relative area between the pole piece and the coating die. The connecting piece and the first die are detachably connected.

16. A pole piece production system, characterized in that: include: A coating device as claimed in any one of claims 1 to 15.

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