Coating machine, coating method and pole piece

Abstract

The application discloses a coating machine, a coating method and an electrode piece. The coating machine comprises at least two intermittent valve groups, each of which is respectively provided with a medium feeding port and a medium discharging port; at least three die heads, a storage cavity and a die head gasket are arranged between two adjacent die heads, and a coating channel is formed between the two adjacent die heads; a driving mechanism is connected with a controlled end of each intermittent valve group, the driving mechanism is used for simultaneously driving each intermittent valve group to act, and the discharging time of the medium discharging port of each intermittent valve group is adjusted; the next intermittent valve group is started before the coating of the previous intermittent valve group is finished, so that overlapping layers are formed between two adjacent coating layers. The application overlaps two adjacent coating layers, the two adjacent coating layers are partially overlapped, the thickness of the coating layer is uniform, the tailing phenomenon of the coating layer is avoided, and the two adjacent coating layers can be seamlessly connected.

Description

Technical Field

[0001] This invention relates to the field of electrode coating manufacturing technology, specifically to a coating machine, coating method, and electrode. Background Technology

[0002] This section provides only background information relevant to this disclosure and does not necessarily constitute prior art.

[0003] Positive and negative electrodes are the core components of a lithium battery, and their processing is the most crucial step in lithium battery manufacturing. Electrodes are divided into positive and negative electrodes, and the tabs on the electrodes are the leads for the positive and negative electrodes, responsible for conducting electricity.

[0004] Current structures and methods that can achieve double-layer coating have problems such as complex control, difficult installation, poor connection between the first and second coating layers, and are only applicable to double-layer coating. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect of poor connection between the first coating layer and the second coating layer when coating the substrate in the current double-layer coating structure, thereby providing a coating machine, coating method and electrode.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0007] A coating machine, comprising:

[0008] At least two intermittent valve groups, each of which is provided with a medium inlet, a medium return outlet and a medium outlet;

[0009] A coating apparatus having at least two coating channels, each of the coating channels being connected to a medium outlet;

[0010] A driving mechanism is connected to the controlled end of each of the intermittent valve groups. The driving mechanism is used to drive the medium inlet of the intermittent valve group to connect with the medium return port or the medium outlet, and to adjust the discharge time of the medium outlet of each intermittent valve group. Before the medium inlet of the previous intermittent valve group connects with the medium return port, the driving mechanism controls the medium inlet of the next intermittent valve group to connect with the medium outlet, so that an overlapping layer is formed between two adjacent coatings.

[0011] The technical solution is further optimized, and the driving mechanism includes:

[0012] A driver having a rotating end connected to a main shaft;

[0013] An intermittent valve group control structure is provided, which is mounted on the main shaft and is used to control the opening and closing of the intermittent valve group when the main shaft rotates.

[0014] To further optimize the technical solution, the intermittent valve group control structure is a concave cam structure or an eccentric wheel structure.

[0015] To further optimize the technical solution, the position of the protrusion or recess of the concave cam structure can be adjusted to adjust the overlap between adjacent coatings.

[0016] The technical solution is further optimized so that the speed of the driver can be adjusted to regulate the coating length.

[0017] To further optimize the technical solution, the coating equipment includes at least three dies, with a material storage cavity and a die gasket between two adjacent dies, and the coating channel is formed between two adjacent dies. The coating channel is connected to the medium outlet through the material storage cavity.

[0018] To further optimize the technical solution, the mold head has a mold head lip, and dispensing channels are provided on both sides of the mold head lip to continuously dispense adhesive onto the substrate.

[0019] To further optimize the technical solution, the intermittent valve group is provided in three groups: the first intermittent valve group, the second intermittent valve group, and the third intermittent valve group.

[0020] The coating equipment includes four dies: a first die, a second die, a third die, and a fourth die. A first coating channel and a first die gasket are provided between the lips of the first and second dies, and the first coating channel is connected to the medium outlet of the first intermittent valve group. A second coating channel and a second die gasket are provided between the lips of the second and third dies, and the second coating channel is connected to the medium outlet of the second intermittent valve group. A third coating channel and a third die gasket are provided between the lips of the third and fourth dies, and the third coating channel is connected to the medium outlet of the third intermittent valve group.

[0021] To further optimize the technical solution, the intermittent valve groups are arranged side by side.

[0022] A coating method, the method being performed based on the aforementioned coating machine, includes the following steps:

[0023] Controlling the movement of the substrate;

[0024] The drive mechanism is controlled to move, and the medium is applied to the substrate through the coating channel to form a coating.

[0025] Adjust the discharge time of the medium outlet of each intermittent valve group, and start the next intermittent valve group before the previous intermittent valve group finishes coating, so that an overlapping layer is formed between adjacent coatings.

[0026] Further optimization of the technical solution also includes the following steps:

[0027] The overlap between adjacent coating layers can be adjusted by adjusting the position of the concave cam structure.

[0028] and / or

[0029] The length of the coating is adjusted by regulating the opening and closing frequency of each intermittent valve group;

[0030] and / or

[0031] By increasing or decreasing the number of intermittent valve groups and corresponding coating channels, the coating of different active substances can be increased or decreased.

[0032] An electrode sheet, the electrode sheet being prepared using the aforementioned coating machine, comprising:

[0033] Substrate;

[0034] Multiple coatings are seamlessly connected on the substrate along the substrate moving direction, and adjacent coatings overlap each other to form an overlapping layer.

[0035] To further optimize the technical solution, an edge adhesive layer is also provided on the substrate, and two edge adhesive layers are provided and located on the left and right sides of each coating.

[0036] To further optimize the technical solution, the overlapping layer is the cutting position during electrode slicing.

[0037] The technical solution of this invention has the following advantages:

[0038] 1. This invention provides a coating machine capable of not only double-layer coating of media, but also triple-layer and multi-layer coating of various media. Since all control is performed by the same drive mechanism, control is simple, and seamless connection between the head and tail sections is achieved. This invention overlaps adjacent coating layers, ensuring uniform thickness of the coating portion (active material portion) and preventing coating tailing, thus enabling seamless connection between adjacent coating layers. Furthermore, when slitting the prepared electrode sheets, the overlapping layer can be used as the slitting point, ensuring that the coating portion does not develop burrs during slitting, thereby improving the production quality of the small electrode sheets.

[0039] 2. The present invention provides a coating machine, wherein the die head has a die head lip, and dispensing channels are provided on both sides of the die head lip to continuously dispense adhesive onto the substrate.

[0040] 3. The coating machine provided by the present invention adopts an intermittent valve group arranged in parallel, which reduces the space occupied and reduces the burden on the die head inlet.

[0041] 4. The coating method provided by this invention adjusts the overlap between adjacent coating layers by adjusting the position of the concave cam structure. That is, the overlap between coating layers can be controlled by adjusting the cam position, eliminating the need for complex program control; direct rotation is sufficient, which is very convenient. The mechanical cam, in conjunction with the opening and closing of each intermittent valve assembly, ensures stability, reliability, and good repeatability.

[0042] 5. The coating method provided by this invention is simple to control. It only requires changing the speed of the actuator, i.e., adjusting the opening and closing frequency of each intermittent valve group, to adjust the length of the coating, enabling the production of electrode sheets of various lengths. The ratio between coatings can be designed and limited according to different design requirements.

[0043] 6. The coating method provided by the present invention can increase or decrease the coating of different active substances by increasing or decreasing the number of intermittent valve groups and corresponding coating channels, thereby achieving coating of different active substances on the substrate. Different coating materials can be selected according to different process requirements. Attached Figure Description

[0044] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of a coating machine according to Embodiment 2 of the present invention;

[0046] Figure 2 A schematic diagram of the structure of a coating machine according to Embodiment 3 of the present invention;

[0047] Figure 3 This is a schematic diagram of the electrode sheet prepared by coating two active substances onto a substrate according to the present invention.

[0048] Figure 4 This is a schematic diagram of the electrode sheet prepared by coating a substrate with a variety of active substances according to the present invention.

[0049] Figure 5 This is a schematic diagram showing the coating process unfolded onto a plane by the double-layer intermittent coating die head of the present invention during actual operation;

[0050] Figure 6This is a schematic diagram showing the coating process unfolded onto a plane by the multi-layer intermittent coating die head of the present invention during actual operation.

[0051] Figure label:

[0052] 1. First coating inlet; 2. Second coating inlet; 3. Third coating inlet; 4. First pressure sensor; 5. Second pressure sensor; 6. Third pressure sensor; 7. First coating return port; 8. Second coating return port; 9. Third coating return port; 13. First die head; 14. Second die head; 15. Third die head; 16. Fourth die head; 17. First die head gasket; 18. Second die head gasket; 19. Third die head gasket; 21. Driver; 22. Edge dispensing port;

[0053] 10. Coating inlet, 20. Dispensing inlet, 30. Coating return port, 40. Dispensing return port, 50. Dispensing die inlet, 60. Coating die inlet, 70. Upper die, 80. Middle die, 90. Lower die, 110. Upper coating die gasket, 111. Lower coating die gasket;

[0054] 101. Substrate; 102. Adhesive layer; 103. Coating layer; 1031. First coating layer; 1032. Second coating layer; 1033. Third coating layer; 104. Coating and adhesive overlapping layer; 105. Edge adhesive layer; 106. Coating overlapping layer. Detailed Implementation

[0055] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0056] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms "a," "an," and "comprising" as used herein may also mean including the plural forms. The terms "comprising," "including," and "having" are inclusive and therefore indicate the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0057] Although terms such as "first," "second," etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Furthermore, in the description of this invention, unless otherwise expressly specified and limited, the terms "set up" and "connected" should be interpreted broadly; for example, they may refer to a fixed connection, a detachable connection, or an integral connection; they may refer to a direct connection or an indirect connection via an intermediate medium. Those skilled in the art will understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0058] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "front," "rear," "center," "inner," "longitudinal," "lateral," "side," "vertical," "outer," etc. Such spatial relative terms are intended to include different orientations of the mechanism in use or operation, in addition to those depicted in the figure. For example, if the mechanism in the figure is flipped, then an element described as "below other elements or features" or "below other elements or features" will subsequently be oriented as "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations. The mechanism may be otherwise oriented (rotated 90 degrees or in other directions), and the spatial relative descriptors used in the text will be interpreted accordingly.

[0059] Positive and negative electrodes are the core components of a lithium battery, and their processing is the most crucial step in lithium battery manufacturing. Electrodes are divided into positive and negative electrodes, and the tabs on the electrodes are the leads for the positive and negative electrodes, responsible for conducting electricity.

[0060] During the coating process, active material is usually continuously coated on the substrate as it moves, and adhesive coatings are applied to both sides of the active material. When the electrode sheet prepared in this way is slit or die-cut, the burrs generated at the active material coating can easily puncture the diaphragm and cause a short circuit during the pairing of positive and negative electrodes.

[0061] Current structures and methods for achieving double-layer coating have drawbacks, including complex control, difficult installation, and poor adhesion between the first and second coating layers, resulting in a tailing phenomenon. This tailing phenomenon occurs because, after the valve closes, the resulting backflow force is insufficient to draw back the slurry (medium) at the lip, leaving residual slurry (medium) coated onto the foil. This results in inconsistent shape and thickness, ultimately affecting the overall density uniformity.

[0062] To further address the issue of seamless connection between coatings in intermittent valves, this invention designs a coating machine and method. The machine utilizes a single actuator, which can be adjusted based on the overlapping portion of the coatings. This invention overlaps adjacent coatings, ensuring uniform thickness of the coating portion (active material portion) and enabling seamless connection between adjacent coatings. Furthermore, when slitting the prepared electrode sheets, the overlapping layer can be used as the slitting point, preventing burrs from forming on the coating portion during slitting and improving the production quality of the small electrode sheets.

[0063] Example 1

[0064] The specific embodiments of the present invention will now be described in detail with reference to the coating machine of the first aspect of the present invention.

[0065] It should be noted that the coating machine of the first aspect of the present invention is only a preferred embodiment of the present invention. The coating machine of the present invention can be the coating machine of the first aspect of the present invention or other structures. For ease of explanation, the coating machine of the first aspect of the present invention will be described in detail below.

[0066] like Figures 1 to 6 As shown in the figure, this embodiment discloses a coating machine, including an intermittent valve group, coating equipment and a drive mechanism.

[0067] The intermittent valve group consists of at least two valves, each equipped with a medium inlet, a medium return outlet, a medium outlet, a valve plate assembly, and a valve plate drive assembly. The valve plate drive assembly controls the raising and lowering of the valve plate assembly, thereby controlling the connection between the medium return outlet and the medium inlet, or between the medium outlet and the medium inlet.

[0068] The coating equipment includes at least three dies, with a material storage cavity and a die gasket between two adjacent dies, and a coating channel is formed between two adjacent dies. Each material storage cavity is connected to a medium outlet and a coating channel, that is, each coating channel is connected to a medium outlet.

[0069] The drive mechanism is connected to the controlled end of each intermittent valve group, that is, the drive mechanism is connected to the valve plate drive assembly of the intermittent valve group. The drive mechanism is used to simultaneously drive the operation of each intermittent valve group and adjust the discharge time of the medium outlet of each intermittent valve group. It starts the next intermittent valve group before the previous intermittent valve group finishes coating, so that an overlapping layer is formed between adjacent coatings. The overlapping layer refers to the coating formed by the overlap of two media.

[0070] Specifically, the drive mechanism simultaneously drives the operation of each intermittent valve group. This means that the drive mechanism controls the intermittent valve group to connect the medium inlet to the medium return port or the medium outlet. When the intermittent valve group's medium inlet is connected to the medium return port, it is in the closed state. When the intermittent valve group's medium inlet is connected to the medium outlet, it is in the open state.

[0071] When the intermittent valve group finishes coating, the medium inlet and the medium return port are connected, but the medium inlet and the medium outlet are not connected; when the intermittent valve group starts coating, the medium inlet and the medium outlet are connected, but the medium inlet and the medium return port are not connected.

[0072] The aforementioned coating machine can achieve not only double-layer coating of media, but also triple-layer and multi-layer coating of various media. Since all controls are performed by the same drive mechanism, control is simple, and seamless connection between the beginning and end is achieved. This invention overlaps adjacent coating layers, ensuring uniform thickness of the coating portion (active material portion), avoiding coating tailing, and enabling seamless connection between adjacent coating layers. Furthermore, when slitting the prepared electrode sheets, the overlapping layer can be used as the slitting point, ensuring that the coating portion does not develop burrs during slitting, thus improving the production quality of the small electrode sheets.

[0073] In some embodiments, the intermittent valve assembly includes a first intermittent valve and a second intermittent valve. The first intermittent valve has a first inlet, a reflux port, and a first valve plate assembly. A drive mechanism controls the movement of the first valve plate assembly to achieve communication control between the first inlet and the reflux port. The second intermittent valve has a second inlet, a discharge port, and a second valve plate assembly. The second inlet is connected to the first inlet. A drive mechanism controls the movement of the second valve plate assembly to achieve communication control between the second inlet and the discharge port.

[0074] In some embodiments, the drive mechanism includes a driver 21 and an intermittent valve group control structure. The driver 21 has a rotating end connected to a main shaft. The intermittent valve group control structure is mounted on the main shaft and is used to control the opening and closing of the intermittent valve group when the main shaft rotates.

[0075] The intermittent valve group control structure is either a concave cam structure or an eccentric wheel structure, both of which convert rotational motion into linear motion. When both the first and second intermittent valve group control structures are concave cam structures, the first intermittent valve group control structure is a cam, and the second intermittent valve group control structure is a concave wheel. As an alternative embodiment, the first intermittent valve group control structure is a concave wheel, and the second intermittent valve group control structure is a cam.

[0076] The cam's protrusion and the concave part of the cam are arranged at the same angle and correspond to each other during rotation, so that the coating and backflow pressure relief of the medium alternately.

[0077] In some embodiments, the position of the protrusion or recess of the concave cam structure can be adjusted. That is, by adjusting the position of the protrusion or recess of the concave cam structure, the opening and closing time of the intermittent valve assembly can be adjusted, the time for the intermittent valve assembly to apply the medium to the substrate can be adjusted, and thus the overlap between adjacent coatings can be adjusted.

[0078] In some embodiments, the speed of the driver 21 is adjustable. That is, when the speed of the driver 21 changes, the running time after the intermittent valve group is activated can be adjusted, thereby adjusting the coating length. When the substrate moving speed remains constant, when the running time after the intermittent valve group is activated becomes longer, the time for the medium to be sprayed onto the substrate is correspondingly longer, and the coating length is longer; conversely, when the substrate moving speed remains constant, when the running time after the intermittent valve group is activated becomes shorter, the time for the medium to be sprayed onto the substrate is correspondingly shorter, and the coating length is shorter.

[0079] In some embodiments, the die head has a die head lip, and dispensing channels are provided on both sides of the die head lip to continuously dispense adhesive onto the substrate.

[0080] To further address the issue of valve bodies occupying space in the die head installation, intermittent valve groups are arranged side-by-side, reducing space usage and lowering the load on the die head inlet.

[0081] The coating method using the above-mentioned coating machine includes the following steps:

[0082] Control the movement of the substrate.

[0083] The drive mechanism is controlled to move, and the medium is applied to the substrate through the coating channel to form a coating.

[0084] Adjust the discharge time of the medium outlet of each intermittent valve group, and start the next intermittent valve group before the previous intermittent valve group finishes coating, so that an overlapping layer is formed between adjacent coatings.

[0085] At the start and end of coating, a very small portion of the coating exhibits uneven thickness. This is because the pressure is rising or falling during the instantaneous start and stop of the concave cam action, leading to uneven coating on that portion of the electrode sheet. In this embodiment, the coating method utilizes an overlapping layer of adhesive to ensure overall coverage; subsequent slicing will be performed from this overlapping layer.

[0086] The overlap between adjacent coatings can be adjusted by changing the position of the concave cam structure. In other words, the overlap between coatings can be controlled by adjusting the cam position; no complex programming is required, just direct rotation, which is very convenient. The mechanical cam, in conjunction with the opening and closing of each intermittent valve assembly, ensures stability, reliability, and good repeatability.

[0087] The control method is simple; by changing the speed of the drive, i.e., adjusting the opening and closing frequency of each intermittent valve group, the length of the coating can be adjusted, enabling the production of electrode sheets of various lengths. The ratio between coatings can be designed and limited according to different design requirements.

[0088] By increasing or decreasing the number of intermittent valve groups and corresponding coating channels, the coating of different active substances can be increased or decreased, enabling the coating of different active substances on the substrate. Different coating materials can be selected according to different process requirements.

[0089] Example 2

[0090] The present invention will now be described in detail using a coating machine including a two-port intermittent valve as an example.

[0091] like Figure 1 , Figure 3 , Figure 5 As shown, this embodiment discloses a coating machine, including a two-port intermittent valve, a pressure sensor, and a coating device. The two-port intermittent valve and the coating device are connected via a pipeline for material supply. By controlling the two-port intermittent valve to perform intermittent coating and dispensing, a double-layer coating is achieved.

[0092] The dual-port intermittent valve uses a motor as its drive component. The left half of the valve has a coating inlet 10, a coating return inlet 30, a coating port, and a coating pressure detection port; the right half has a dispensing inlet 20, a dispensing return inlet 40, a dispensing port, and a dispensing pressure detection port. The motor drives the valve body to open and close, achieving intermittent coating and dispensing functions. Pressure sensors are installed at the coating and dispensing pressure detection ports to detect pressure changes during the coating and dispensing process.

[0093] The coating equipment is equipped with a dispensing die inlet 50 and a coating die inlet 60, which are sequentially connected to the dispensing port and coating port of a dual-port intermittent valve via pipelines. The coating equipment consists of a lower die 90, a middle die 80, and an upper die 70. A dispensing channel and a lower coating die gasket 111 are located at the midpoint of the lip connecting the lower die 90 and the middle die 80. A coating channel and an upper coating die gasket 110 are located at the midpoint of the lip connecting the upper die 70 and the middle die 80. Edge dispensing ports 22 are located on both sides of the coating lip, allowing for continuous dispensing of adhesive onto the substrate.

[0094] See Figure 3 and Figure 5 The double-layer coating method of the above-mentioned coating machine is as follows:

[0095] During the movement of the substrate, the dispensing channels on both sides of the coating lip continuously apply the dispensing coating slurry to both sides of the substrate, forming the dispensing layer 102.

[0096] The coating slurry is applied to the substrate through the intermediate channel of either the first coating lip or the second coating lip. After coating to the first pre-formed length, the coating stops due to the action of the concave cam of the dual-port intermittent valve, forming coating layer 103 (positive and negative electrode layers).

[0097] After coating layer 103 stops coating, the adhesive material is applied to the substrate through the middle channel of the other of the first and second lips. After the adhesive is applied to the pre-set length, coating stops, forming a coating-adhesive overlap layer 104. That is, part of the adhesive material covers the coating layer, which serves to prevent the coating layer from having a trailing effect.

[0098] The coating is applied alternately to the substrate to form a coating layer 103 and an adhesive layer 102 until the coating is completed.

[0099] Example 3

[0100] The present invention will now be described in detail using a coating machine including a multi-port intermittent valve as an example.

[0101] like Figure 2 , Figure 4 , Figure 6 As shown, this embodiment discloses a coating machine, including a multi-port intermittent valve, a pressure detection sensor, and a coating device. Similar to the double-layer coating method, the multi-port intermittent valve and the coating device are connected via pipelines for material supply. By controlling the multi-port intermittent valve to perform intermittent coating, various different active substances can be intermittently coated on the substrate.

[0102] The multi-port intermittent valve uses a motor as its drive connection, allowing adjustment of the intermittent length of active material coating by changing the rotation speed. The left end of the multi-port intermittent valve has a first coating inlet 1, a first coating return port 7, a first coating port, and a first coating pressure detection port; the middle section has a second coating inlet 2, a second coating return port 8, a second coating port, and a second coating pressure detection port; the right end has a third coating inlet 3, a third coating return port 9, a third coating port, and a third pressure detection port. All pressure detection ports are equipped with pressure sensors to detect the feed pressure of different active materials. The first coating pressure detection port is equipped with a first pressure sensor 4, the second coating pressure detection port with a second pressure sensor 5, and the third coating pressure detection port with a third pressure sensor 6.

[0103] The coating equipment is equipped with a first coating inlet, a second coating inlet, and a third coating inlet, which are interconnected with the coating ports of a multi-port intermittent valve via pipelines. The coating equipment consists of a first die 13, a second die 14, a third die 15, and a fourth die 16. A first coating channel and a first die gasket 17 are provided between the lips of the first die 13 and the second die 14; a second coating channel and a second die gasket 18 are provided between the lips of the second die 14 and the third die 15; and a third coating channel and a third die gasket 19 are provided between the lips of the third die 15 and the fourth die 16. Edge dispensing nozzles 22 are provided on both sides of the coating die lips, enabling continuous dispensing of adhesive onto the substrate.

[0104] See Figure 4 and Figure 6 The multi-layer coating method of the above-mentioned coating machine is as follows:

[0105] During the movement of the substrate, the dispensing channels on both sides of the die head lip continuously apply the dispensing coating slurry to both sides of the substrate, forming a dispensing layer.

[0106] The first active substance is coated onto the substrate through the middle channel (first coating port) between the first mold head 13 and the lip of the second mold head. After coating to the first pre-made length, coating is stopped to form the first coating layer 1031.

[0107] The intermediate channel (second coating port) between the middle lips of the second mold head 14 and the third mold head 15 coats the second active material onto the substrate. After coating to the second pre-formed length, coating is stopped to form the second coating layer 1032.

[0108] The third active material is coated onto the substrate through the middle channel (third coating port) between the middle lips of the third mold head 15 and the fourth mold head 16. After coating to the third pre-formed length, coating is stopped to form the third coating layer 1033.

[0109] The coating is applied alternately to the substrate to form a first coating layer 1031, a second coating layer 1032, and a third coating layer 1033 until the coating is completed. Coating overlap layers 106 are formed between the first coating layer 1031 and the second coating layer 1032, and between the second coating layer 1032 and the third coating layer 1033.

[0110] It should be noted that, whether it is a double-layer coating or a multi-layer coating, the length, width, and ratio between coatings can be changed according to actual design requirements; the coating material can be selected according to actual needs.

[0111] Example 4

[0112] The specific embodiments of the present invention will now be described in detail with reference to the electrode sheet of the second aspect of the present invention.

[0113] It should be noted that the electrode sheet of the second aspect of the present invention is only a preferred embodiment of the present invention. The electrode sheet of the present invention can adopt the electrode sheet of the second aspect of the present invention or other structures. For ease of explanation, the electrode sheet of the second aspect of the present invention will be described in detail below.

[0114] like Figure 3 and Figure 4 As shown, this embodiment discloses an electrode sheet, which is prepared using a coating machine and includes a substrate 101 and multiple coatings. The substrate 101 is a foil. Each coating is seamlessly connected on the substrate 101 along the moving direction of the substrate 101, and adjacent coatings overlap each other to form an overlapping layer.

[0115] The overlapping layer is the cutting location during electrode slicing. Subsequent slicing processes will cut from the overlapping layer to ensure that the Martian material portion after slicing or die-cutting will not produce burrs. The overlapping layer should not be too large, generally within 2mm, or even shorter.

[0116] An edge adhesive layer 105 is also provided on the substrate 101. Two edge adhesive layers 105 are provided and located on the left and right sides of each coating.

[0117] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A coater characterized by comprising: The coating machine comprises: at least two intermittent valve groups, each of which is provided with a medium feeding port, a medium return port and a medium discharging port; a coating device having at least two coating channels, each of which is in communication with one of the medium discharging ports; a driving mechanism connected to the controlled end of each of the intermittent valve groups, which is used to drive the medium feeding port of each of the intermittent valve groups to be in communication with the medium return port or the medium discharging port, and to adjust the discharging time of the medium discharging port of each of the intermittent valve groups, and to control the medium feeding port of the next intermittent valve group to be in communication with the medium discharging port before the medium feeding port of the previous intermittent valve group is in communication with the medium return port, so as to form an overlapping layer between two adjacent coating layers; the driving mechanism comprises: a driver (21) having a rotating end connected with a main shaft; an intermittent valve group control structure provided on the main shaft, which is used to control the opening and closing of the intermittent valve groups when the main shaft rotates; the intermittent valve group control structure is a concave-convex cam structure or an eccentric wheel structure; the position of the convex part or the concave part of the concave-convex cam structure can be adjusted to adjust the overlap amount between adjacent coating layers.

2. The coater according to claim 1, characterized in that, The coating device comprises at least three die heads, and each of the die heads is provided with a storage cavity and a die head gasket between two adjacent die heads, and the coating channel is formed between two adjacent die heads, and the coating channel is in communication with the medium discharging port through the storage cavity.

3. The coater according to claim 2, characterized in that The die head has a die head lip, and both sides of the die head lip are provided with glue dispensing channels to continuously dispense glue on the substrate.

4. The coater according to claim 2, characterized by The intermittent valve group is provided with three groups, i.e., a first intermittent valve group, a second intermittent valve group and a third intermittent valve group; The coating device comprises four die heads, i.e., a first die head (13), a second die head (14), a third die head (15) and a fourth die head (16); the first die head (13) and the second die head (14) are provided with a first coating channel and a first die head gasket (17) between the lips of the two die heads, and the first coating channel is in communication with the medium discharging port of the first intermittent valve group; the second die head (14) and the third die head (15) are provided with a second coating channel and a second die head gasket (18) between the lips of the two die heads, and the second coating channel is in communication with the medium discharging port of the second intermittent valve group; the third die head (15) and the fourth die head (16) are provided with a third coating channel and a third die head gasket (19) between the lips of the two die heads, and the third coating channel is in communication with the medium discharging port of the third intermittent valve group.

5. A coating method characterized by, The method is based on the coating machine according to any one of claims 1-4, and comprises the following steps: controlling the movement of the substrate; controlling the movement of the driving mechanism to coat the medium on the substrate through the coating channel to form a coating layer; adjusting the discharging time of the medium discharging port of each intermittent valve group, and starting the next intermittent valve group before the previous intermittent valve group finishes coating, so as to form an overlapping layer between two adjacent coating layers.

6. The coating method according to claim 5, characterized in that The method further comprises the following steps: The overlapping amount between two adjacent coating layers is adjusted by adjusting the position of the concave-convex wheel structure; and / or The length of the coating layer is adjusted by adjusting the opening and closing frequency of each intermittent valve group; and / or The coating of different active substances is increased or decreased by increasing or decreasing the number of intermittent valve groups and corresponding coating channels.

7. A pole piece characterized by, The pole piece is prepared by using the coating machine of any one of claims 1-4, comprising: a substrate (101); a plurality of coating layers, each of which is arranged on the substrate (101) in a seamless manner along the moving direction of the substrate (101), and the two adjacent coating layers are overlapped with each other and form an overlapping layer.

8. The pole piece of claim 7, wherein The substrate (101) is also provided with an edge dispensing layer (105), and the edge dispensing layer (105) is provided with two and located on the left and right sides of each coating layer; and / or The overlapping layer is the cutting position when the pole piece is cut.

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