Coating gasket assembly and coating device

Abstract

The utility model provides a coating gasket assembly and a coating device.The coating gasket assembly comprises a first gasket and a second gasket, the first gasket comprises a first main body, the first main body is provided with a first main flow channel and a first auxiliary flow channel, and the first main flow channel penetrates through the first main body at the first main discharging end; the first auxiliary runner penetrates through the first main body at the first auxiliary discharging end; the second gasket comprises a second main body, a second runner is arranged on the second main body, and the second runner penetrates through the second main body at the second discharging end; in the first direction, the interval between the first main discharging end and the first auxiliary discharging end is L1, the length of the first auxiliary discharging end is L2, the length of the first main discharging end is L3, the length of the second discharging end is L4, L3 is smaller than L4, and L4 is smaller than L1 + L2 + L3. The first gasket and the second gasket of the coating gasket assembly are matched for use, so that the stress of the negative pole piece can be improved during coating, and the use reliability of the battery monomer is improved. And moreover, the coated insulating material can provide insulation, is not easy to damage, and is small in coating amount.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a coating gasket assembly and a coating device. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, such as in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric airplanes and electric tools.

[0003] In battery design, in order to reduce the risk of lithium plating on the negative electrode plate, the size of the lithium ion receiving area in the negative electrode plate is usually larger than the size of the lithium ion providing area in the positive electrode plate. Such a setting will make the area of ​​the negative electrode plate that exceeds the positive electrode plate have no supporting force in the lithium ion electron receiving area (such as the lithium deposition area), resulting in stress problems. The coating gasket of the related technology cannot solve the current problem when assisting in coating the electrode plate. Utility Model Content

[0004] In view of the above problems, the present application provides a coating gasket assembly and a coating device, wherein the coating gasket assembly can improve the stress of the pole piece.

[0005] In the first aspect, some embodiments of the present application provide a coating gasket assembly, which comprises a first gasket, the first gasket comprises a first main body, the first main body is provided with a first main channel and a first secondary channel, the first main channel penetrates the first main body at the first main discharge end, and the first secondary channel penetrates the first main body at the first secondary discharge end; a second gasket, the second gasket comprises a second main body, the second main body is provided with a second channel, and the second channel penetrates the second body at the second discharge end; along the first direction, the interval between the first main discharge end and the first secondary discharge end is L1, the length of the first secondary discharge end is L2, the length of the first main discharge end is L3, and the length of the second discharge end is L4, L3<L4, L4<L1+L2+L3.

[0006] In the technical solution of the above embodiment, the first gasket and the second gasket of the coating gasket assembly are used together to form a lower coating layer and an upper coating layer on the positive electrode sheet, thereby improving the coating quality of the positive electrode active material. When double-layer coating is performed, the insulating material can be extruded through the first auxiliary discharge end to increase the coated area of ​​the positive electrode sheet and reduce the coating area difference between the positive electrode sheet and the negative electrode sheet, so that the negative electrode sheet and the positive electrode sheet can obtain the support force of the positive electrode sheet after assembly, thereby improving the stress of the negative electrode sheet, reducing the accumulation and release of lithium ions, and improving the reliability of the battery cell. Moreover, along the first direction, L3<L4, L4<L1+L2+L3, so after coating through the first gasket and the second gasket, the coated insulating material can cover the top and outside of the lower coating at the end of the lower coating. First, the insulating material can provide insulation at the end of the upper coating and the end of the lower coating at the same time. Second, the insulating material can be supported by the lower coating and is not easily damaged in subsequent processes. Third, the coating amount of the insulating material can be reduced, thereby improving the energy density of the positive electrode plate.

[0007] According to the coating gasket assembly provided in some embodiments of the present application, on the first body, the number ratio of the first main flow channel to the first secondary flow channel is 1:2; along the first direction, two first secondary flow channels are symmetrically arranged on both sides of each first main flow channel, and L3<L4, L4<2×(L1+L2)+L3. In this way, the Overhang can be compensated on both sides of the positive electrode active material, reducing the difference in the coating area of ​​the positive electrode plate and the negative electrode plate, and improving the stress.

[0008] According to the coating gasket assembly provided in some embodiments of the present application, along the first direction, the difference between 2×(L1+L2)+L3 and L4 ranges from 1 mm to 2 mm. In this way, the insulation requirements of the positive electrode tab area can be met and the reliability can be improved.

[0009] According to the coating gasket assembly provided in some embodiments of the present application, along the first direction, L1<L2, L2<L3. In this way, the energy density of the coated positive electrode sheet can be improved, and the slurry extruded from the first outlet flow channel and the first secondary flow channel can be easily fitted.

[0010] According to the coating gasket assembly provided in some embodiments of the present application, the first main flow channel includes a first main feed section and a first main discharge section which are sequentially connected along the second direction, and the first main discharge section passes through the first main body at the first main discharge end; along the first direction, the first main feed section is provided with adjustment grooves on both sides, and the adjustment grooves are located on the first surface of the first main body and are connected to the first main feed section; along the third direction, the first main flow channel passes through the first body, and the depth of the adjustment grooves is less than the depth of the first main feed section; the first direction, the second direction, and the third direction are perpendicular to each other. In this way, it is convenient to control the flow rate of the slurry during coating.

[0011] According to the coating gasket assembly provided in some embodiments of the present application, the first secondary flow channel includes a first secondary feed port, a front transition section, a middle transition section, a rear transition section and a first secondary discharge section which are sequentially connected along the second direction, and the first secondary discharge section penetrates the first body at the first secondary discharge end; along the third direction, the middle transition section and the first secondary discharge section both penetrate the first body, the first secondary feed port and the front transition section are both located on the first surface of the first body, and the rear transition section is located on the second surface of the first body; along the second direction, the middle transition section and the first secondary discharge section are located on both sides of the adjustment groove. In this way, the change of the slurry flow path in the first secondary flow channel can be achieved, so that the first secondary flow channel and the adjustment groove do not interfere with each other.

[0012] According to the coating gasket assembly provided in some embodiments of the present application, the first secondary discharge section includes a secondary thinning area and a secondary coating area; along the first direction, the secondary thinning area is located on a side close to the first main flow channel, and the secondary coating area is located on a side away from the first main flow channel. In this way, the accumulation of slurry can be reduced and the coating quality can be improved.

[0013] According to the coating gasket assembly provided in some embodiments of the present application, along the third direction, the secondary thinning area is located on the first surface, and the secondary coating area runs through the first body, so as to facilitate the processing of the first gasket and enable the insulating material to cover more fully during coating.

[0014] According to the coating gasket assembly provided in some embodiments of the present application, along the first direction, the length of the secondary thinning area is greater than the length of the secondary coating area. In this way, the structural strength at the first secondary discharge section can be improved, the slurry accumulation can be reduced, and the slurry extruded from the first secondary flow channel can cover the lower coating layer.

[0015] According to the coating gasket assembly provided in some embodiments of the present application, the first main discharge section includes a main thinning area and a main coating area; along the first direction, the main thinning area is located at both ends of the first main discharge section, and the main coating area is located between the two main thinning areas; along the third direction, the main thinning area is located on the first surface, and the main coating area runs through the first body. In this way, the coating quality can be improved and the stress on the first body can be improved.

[0016] According to the coating gasket assembly provided in some embodiments of the present application, along the second direction, the first secondary discharge section is flared, the cross-sectional area of ​​the secondary thinning zone gradually increases, and the secondary coating zone extends away from the first main flow channel. In this way, when the slurry flows, the slurry coating thickness can be thinned to improve the coating quality.

[0017] According to the coating gasket assembly provided in some embodiments of the present application, the first secondary discharge section further includes a convergence zone; along the second direction, the convergence zone is located between the rear transition section and the secondary thinning zone, and the cross-sectional area of ​​the convergence zone is greater than the sum of the cross-sectional areas of the secondary thinning zone and the secondary coating zone. In this way, the continuity of the slurry can be improved, thereby improving the coating quality.

[0018] According to the coating gasket assembly provided in some embodiments of the present application, the thickness of the second body is greater than the thickness of the first body; the thickness of the first body ranges from 0.4 mm to 1 mm; the thickness of the second body ranges from 0.6 mm to 1.4 mm. In this way, when coating the positive electrode sheet, the risk of the insulating material slurry being damaged in subsequent processes can be reduced.

[0019] According to some embodiments of the present application, the coating gasket assembly further includes a third gasket, the third gasket includes a third body, a third flow channel is provided on the third body, and a third discharge end is provided in the third flow channel; the length of the third discharge end along the fourth direction is L5, and L5=L2. In this way, by coating the negative electrode plate with the third gasket, the thickness difference between the positive electrode active material and the insulating material on the positive electrode plate can be compensated, and the stress of the positive electrode plate can be at least partially improved.

[0020] According to the coating gasket assembly provided in some embodiments of the present application, along the fourth direction, the third flow channels are arranged in pairs and symmetrically distributed on the third body; along the fourth direction, the interval between the two third discharge ends is L6, L6=L3+2×L1. In this way, the thickness difference between the positive electrode active material and the insulating material on the positive electrode plate can be compensated to improve stress.

[0021] According to the coating gasket assembly provided in some embodiments of the present application, the third flow channel includes a third feed section, a transmission section and a third discharge section; the third feed section is connected to one end of the transmission section, the other end of the transmission section is connected to the third discharge section, and the third discharge section penetrates the third body at the third discharge end; along the fifth direction, the third feed section and the transmission section are both located on a surface of the third body, and the third discharge section penetrates the third body; the fourth direction intersects with the fifth direction. In this way, the contamination of the slurry to the coating die head can be reduced, and the flow rate of the slurry at the third discharge end can be increased.

[0022] According to the coating gasket assembly provided in some embodiments of the present application, along the sixth direction, the third discharge section includes an accumulation section and an extrusion section that are connected; along the sixth direction, the cross-sectional area of ​​the extrusion section gradually increases, and the cross-sectional area of ​​the accumulation section is greater than the cross-sectional area of ​​the extrusion section; the fourth direction, the fifth direction, and the sixth direction are perpendicular to each other. In this way, the coating quality can be improved, and the slurry can be easily coated on the negative electrode active material.

[0023] According to the coating gasket assembly provided in some embodiments of the present application, the thickness of the third body ranges from 0.4 mm to 1.4 mm. In this way, the third body can be flexibly designed.

[0024] In a second aspect, some embodiments of the present application provide a coating device, which includes a coating die and a coating gasket assembly provided by the above technical solution; the coating gasket assembly is used to be installed on the coating die.

[0025] The technical solution provided by the embodiments of the present disclosure brings at least the following beneficial effects:

[0026] Some embodiments of the present application provide a coating gasket assembly and a coating device, the coating gasket assembly includes a first gasket and a second gasket, the first gasket and the second gasket are used together to perform double-layer coating on the positive electrode plate, and improve the coating quality of the positive electrode active material. When performing double-layer coating, the insulating material can be extruded through the first auxiliary discharge end to increase the area of ​​the positive electrode plate to be coated, thereby reducing the coating area difference between the positive electrode plate and the negative electrode plate, so that the negative electrode plate and the positive electrode plate can obtain the support force of the positive electrode plate after assembly, thereby improving the stress of the negative electrode plate, reducing the accumulation and release of lithium ions, and improving the reliability of the battery cell. Moreover, along the first direction, L3<L4, L4<L1+L2+L3, after coating through the first gasket and the second gasket, the coated insulating material can cover the top and outside of the lower coating at the end of the lower coating. First, the insulating material can provide insulation at the end of the upper coating and the end of the lower coating at the same time. Second, the insulating material can be supported by the lower coating and is not easily damaged in subsequent processes. Third, the coating amount of the insulating material can be reduced, thereby improving the energy density of the positive electrode sheet.

[0027] 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

[0028] By reading the detailed description of the preferred embodiment below, various other advantages and benefits will become clear to those of ordinary skill in the art. The accompanying drawings are only used for the purpose of illustrating the preferred embodiment and are not considered to be limitations of the present application. In addition, the same reference symbols are used to represent the same components throughout the accompanying drawings.

[0029] Figure 1 This is a schematic structural diagram of a first gasket in some embodiments of the present application;

[0030] Figure 2 for Figure 1 A structural schematic diagram of a first gasket from one perspective is shown;

[0031] Figure 3 for Figure 1 A schematic structural diagram of the first gasket from another perspective;

[0032] Figure 4 for Figure 2 A local enlarged view at point A;

[0033] Figure 5 for Figure 4 A local enlarged view at C;

[0034] Figure 6 for Figure 3 A local enlarged view at point B;

[0035] Figure 7 This is a schematic diagram of the structure of a coating die head according to some embodiments of the present application;

[0036] Figure 8 for Figure 7 A cross-sectional view of the coating die shown;

[0037] Fig. 9 This is a schematic diagram of the structure of the second gasket in some embodiments of the present application;

[0038] Fig.10 for Fig. 9 A structural schematic diagram of a second gasket from one perspective is shown;

[0039] Fig.11 is a schematic diagram of the positional relationship between the first gasket and the second gasket;

[0040] Fig.12 for Fig.11 A structural schematic diagram of the first gasket and the second gasket from one perspective;

[0041] Fig.13 for Fig.12 A local enlarged view at D;

[0042] Fig.14 A schematic diagram of the structure of a third gasket in some embodiments of the present application;

[0043] Fig.15 for Fig.14 A structural schematic diagram of a third gasket from one perspective is shown;

[0044] Fig.16 for Fig.15 A local enlarged view at E;

[0045] Fig.17 for Fig.14 A schematic structural diagram of the third gasket from another perspective;

[0046] Fig.18 A schematic diagram of the disassembly of an electrode body provided in some embodiments of the present application.

[0047] In the attached picture:

[0048] 1-first gasket; 11-first main body; 12-first main flow channel; 121-first main feeding section; 1211-adjusting groove; 122-first main discharging section; 1221-main thinning zone; 1222-main coating zone; 13-first secondary flow channel; 131-front transition section; 132-middle transition section; 133-first secondary discharging section; 134-rear transition section; 1331-convergence zone; 1332-secondary coating zone; 1333-secondary thinning zone;

[0049] 2-upper die head; 3-middle die head; 5-lower die head;

[0050] 4-second gasket; 41-second body; 42-second flow channel;

[0051] 6-third gasket; 61-third main body; 62-third flow channel; 621-third feeding section; 622-transmission section; 623-third discharging section; 6231-accumulation section; 6232-extrusion section;

[0052] 7-isolating member; 8-first pole piece; 81-first substrate; 82-first protrusion; 83-first film layer; 9-second pole piece; 91-second substrate; 92-second protrusion; 93-second lower film layer; 94-second upper film layer;

[0053] X1-first direction; Y1-second direction; Z1-third direction; X2-fourth direction; Y2-sixth direction; Z2-fifth direction. DETAILED DESCRIPTION

[0054] 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.

[0055] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in the embodiments of the present application should have the common meanings understood by technicians in the field to which the embodiments of the present application belong.

[0056] In the description of the embodiments of the present application, the orientations or positional relationships indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", and "circumferential" are based on the orientations or positional relationships shown in the accompanying drawings and 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.

[0057] In addition, the technical terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number 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.

[0058] 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 ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0059] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0060] With the development of new energy technologies, batteries are being used more and more widely. In battery design, in order to reduce the risk of lithium plating on the negative electrode, an overhang design is usually performed, that is, the size of the area in the negative electrode that receives lithium ions is usually larger than the size of the area in the positive electrode that provides lithium ions. Such a design will cause the area in the negative electrode that exceeds the positive electrode to not be supported by the positive electrode in the lithium ion electron receiving area. The negative electrode has stress problems, poor lithium deposition morphology, and is prone to produce high-porosity dead lithium or dendritic lithium, resulting in lithium powder accumulation during the cycle. This part of the lithium powder may be freed to the positive electrode side through the electrolyte, resulting in abnormal capacity or short circuit, causing the isolation membrane to melt and even thermal runaway of the battery cell, deteriorating the reliability of the battery cell.

[0061] In view of this, the present application provides a coating gasket assembly and a coating device.

[0062] Please refer to Figures 1 to 18 , Figure 1 This is a schematic structural diagram of a first gasket in some embodiments of the present application; Figure 2 for Figure 1 A structural schematic diagram of a first gasket from one perspective is shown; Figure 3for Figure 1 A schematic structural diagram of the first gasket from another perspective; Figure 4 for Figure 2 A local enlarged view at point A; Figure 5 for Figure 4 A local enlarged view at C; Figure 6 for Figure 3 A local enlarged view at point B; Figure 7 This is a schematic diagram of the structure of a coating die head according to some embodiments of the present application; Figure 8 for Figure 7 A cross-sectional view of the coating die shown; Fig. 9 This is a schematic diagram of the structure of the second gasket in some embodiments of the present application; Fig.10 for Fig. 9 A structural schematic diagram of a second gasket from one perspective is shown; Fig.11 is a schematic diagram of the positional relationship between the first gasket and the second gasket; Fig.12 for Fig.11 A structural schematic diagram of the first gasket and the second gasket from one perspective; Fig.13 for Fig.12 A local enlarged view at D; Fig.14 A schematic diagram of the structure of a third gasket in some embodiments of the present application; Fig.15 for Fig.14 A structural schematic diagram of a third gasket from one perspective is shown; Fig.16 for Fig.15 A local enlarged view at E; Fig.17 for Fig.14 A schematic structural diagram of the third gasket from another perspective; Fig.18 A schematic diagram of the disassembly of an electrode body provided in some embodiments of the present application.

[0063] First, as Figures 1 to 6 , Figures 9 to 13 As shown, some embodiments of the present application provide a coating gasket assembly, which includes a first gasket 1 and a second gasket 4; the first gasket 1 includes a first main body 11, the first main body 11 is provided with a first main channel 12 and a first secondary channel 13, the first main channel 12 penetrates the first main body 11 at the first main discharge end, and the first secondary channel 13 penetrates the first main body 11 at the first secondary discharge end; the second gasket 4 includes a second main body 41, the second main body 41 is provided with a second channel 42, and the second channel 42 penetrates the second body 41 at the second discharge end; along the first direction X1, the interval between the first main discharge end and the first secondary discharge end is L1, the length of the first secondary discharge end is L2, the length of the first main discharge end is L3, the length of the second discharge end is L4, L3<L4, L4<L1+L2+L3.

[0064] like Figure 7 and Figure 8As shown, the first gasket 1 and the second gasket 4 are used together and can be installed on the coating die of the coating device to perform double-layer coating on the positive electrode sheet. The first gasket 1 is installed between the upper die 2 and the middle die 3, and the second gasket 4 is installed between the middle die 3 and the lower die 5. The second gasket 4 is used to cooperate with the coating die to coat the lower coating on the substrate of the positive electrode sheet, and the first gasket 1 is used to cooperate with the coating die to coat the upper coating on the lower coating. The angle between the first gasket 1 and the second gasket 4 can be set according to the coating die, for example, the angle between the first gasket 1 and the second gasket 4 can be 30°. On the first main body 11, the first main channel 12 and the first secondary channel 13 are independent of each other. The first main channel 12 can extrude slurry at the first main discharge end, and the first secondary channel 13 can extrude slurry at the first secondary discharge end. On the second main body 41, the second channel 42 can extrude slurry at the second discharge end. The slurry material extruded from the first main flow channel 12 and the second flow channel 42 is a positive electrode active material, and the slurry extruded from the first secondary flow channel 13 is an insulating material.

[0065] The slurry composition extruded from the second flow channel 42 and the first main flow channel 12 may be the same or different. For example, the positive electrode active material may include phosphate, layered transition metal oxide and their respective modified compounds. The insulating material may be at least one of an inorganic insulating material and an organic insulating material, the inorganic insulating material may include inorganic ceramic particles, and the organic insulating material may include one or more of polyolefin, epoxy resin, polyacrylic acid PPA, and styrene-butadiene rubber SBR.

[0066] Along the first direction X1, L3<L4, when the first gasket 1 and the second gasket 4 are installed on the coating die head, projected along the direction perpendicular to the thickness of the first gasket 1, the outline of the first main discharge end is located within the outline of the second discharge end.

[0067] Along the first direction X1, L4<L1+L2+L3, when applying the slurry to the positive electrode sheet, the lower coating is the positive electrode active material coating, the upper coating includes an active portion coated with the positive electrode active material and an insulating portion coated with the insulating material, and the insulating portion is attached to the active portion at the end of the active portion. At the end of the lower coating, the insulating portion covers the upper and outer sides of the lower coating.

[0068] In the technical solution of the above embodiment, the coating gasket assembly includes a first gasket 1 and a second gasket 4. The first gasket 1 and the second gasket 4 are used together to perform double-layer coating on the positive electrode plate to form a lower coating layer and an upper coating layer, thereby improving the coating quality of the positive electrode active material. When performing double-layer coating, the insulating material can be extruded through the first auxiliary discharge end to increase the coated area of ​​the positive electrode plate, thereby reducing the coating area difference between the positive electrode plate and the negative electrode plate, so that the negative electrode plate and the positive electrode plate can obtain the support force of the positive electrode plate after assembly, thereby improving the stress of the negative electrode plate, reducing the accumulation and release of lithium ions, and improving the reliability of the battery cell. Moreover, along the first direction X1, L3<L4, L4<L1+L2+L3, so after coating through the first gasket 1 and the second gasket 4, the coated insulating material can cover the upper and outer sides of the lower coating at the end of the lower coating. Firstly, the insulating material can provide insulation at the end of the upper coating and the end of the lower coating at the same time. Secondly, the insulating material can be supported by the lower coating and is not easily damaged in subsequent processes. Thirdly, the coating amount of the insulating material can be reduced, thereby improving the energy density of the positive electrode sheet.

[0069] In some embodiments of the present application, Figures 1 to 4 As shown, the ratio of the number of the first main flow channel 12 to the first secondary flow channel 13 is 1:2; along the first direction X1, two first secondary flow channels 13 are symmetrically arranged on both sides of each first main flow channel 12, and L3<L4, L4<2×(L1+L2)+L3.

[0070] On the first main body 11, there can be one or more first main channels 12. When the number of first main channels 12 is one, the number of first secondary channels 13 is two, and at this time, coating of one positive electrode sheet can be achieved in the first direction X1. When there are multiple first main channels 12, the number of first secondary channels 13 is twice the number of first main channels 12, and each first main channel 12 is equipped with two first secondary channels 13, and at this time, multiple positive electrode sheets can be coated simultaneously in the first direction X1.

[0071] In the technical solution of the above embodiment, each first main flow channel 12 is equipped with a first secondary flow channel 13 on both sides. When coating the positive electrode plate, the positive electrode active material on both sides of the positive electrode plate is insulating material, so that Overhang (the part of the negative electrode plate that receives lithium ions is more than the positive electrode plate that provides lithium ions) can be compensated on both sides of the positive electrode active material, thereby reducing the difference in coating area between the positive electrode plate and the negative electrode plate and improving stress.

[0072] In some embodiments of the present application, Figure 5 , Figures 10 to 13 As shown, along the first direction X1, the difference between 2×(L1+L2)+L3 and L4 ranges from 1 mm to 2 mm.

[0073] Illustratively, the difference may be 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, or 2 mm, or any intermediate value between any two adjacent values ​​mentioned above.

[0074] In the technical solution of the above embodiment, the second gasket 4 is used in conjunction with the first gasket 1 to coat the positive electrode plate, so that the length of the lower coating layer can be less than the length of the upper coating layer, so that the insulating material can be sealed at both ends of the positive electrode active material. In addition, the difference between the upper coating layer and the lower coating layer is 1mm to 2mm, so that the length of the insulating material on one side of the positive electrode active material is at least 0.5mm, which can meet the insulation requirements of the positive electrode tab area, avoid the free deposition of lithium ions, generate high-porosity dead lithium or dendritic lithium, reduce the risk of lithium powder drifting to the edge of the positive electrode active material to cause self-discharge and heat release, and improve reliability.

[0075] In some embodiments of the present application, Figure 5 As shown, along the first direction X1, L1<L2, L2<L3.

[0076] In the first direction X1, L2<L3, the slurry extruded from the first auxiliary discharge end is used as a supplement to the slurry extruded from the first main discharge end, and its coating length in the first direction X1 is less than the coating length of the slurry extruded from the first main discharge end. Exemplarily, L2:L3<1:10, which can be 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20; L1:L2<1:10, which can be 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19, 1:20.

[0077] In the technical solution of the above embodiment, along the first direction X1, L2<L3, the coating area of ​​the slurry extruded from the first auxiliary discharge end on the positive electrode sheet can be reduced, and the proportion of the slurry extruded from the first main discharge end on the positive electrode sheet can be increased, thereby increasing the energy density of the positive electrode sheet. L1<L2, the interval between the first main discharge end and the first auxiliary discharge end can be reduced, so that the slurry extruded from the first main flow channel 12 and the first auxiliary flow channel 13 can be attached to each other on the basis of their independence.

[0078] In some embodiments of the present application, Figure 4As shown, the first main channel 12 includes a first main feed section 121 and a first main discharge section 122 which are sequentially connected along the second direction Y1, and the first main discharge section 122 passes through the first main body 11 at the first main discharge end; along the first direction X1, adjustment grooves 1211 are provided on both sides of the first main feed section 121, and the adjustment grooves 1211 are located on the first surface of the first main body 11 and communicate with the first main feed section 121; along the third direction Z1, the first main channel 12 passes through the first main body 11, and the depth of the adjustment groove 1211 is less than the depth of the first main feed section 121; the first direction X1, the second direction Y1, and the third direction Z1 are perpendicular to each other.

[0079] When coating the positive electrode sheet, the slurry enters the first main feed section 121 through the coating die head, then enters the first main discharge section 122 from the first main feed section 121, and is extruded from the first main discharge end to achieve coating of the positive electrode sheet. In the first direction X1, the adjustment grooves 1211 are symmetrically distributed on both sides of the first main feed section 121. The adjustment grooves 1211 are grooves formed by concavely pressing the first surface of the first body 11, and do not penetrate the first body 11. The first direction X1 can be along the length direction of the first gasket 1, the second direction Y1 can be along the width direction of the first gasket 1, and the third direction Z1 can be along the thickness direction of the first gasket 1.

[0080] In the technical solution of the above embodiment, regulating grooves 1211 are provided on both sides of the first main feeding section 121, and the regulating grooves 1211 can avoid the flow blocks of the coating die head, so as to facilitate the control of the flow rate of the slurry during coating.

[0081] In some embodiments of the present application, Figures 1 to 6 As shown, the first secondary flow channel 13 includes a first secondary feed port, a front transition section 131, a middle transition section 132, a rear transition section 134 and a first secondary discharge section 133 which are sequentially connected along the second direction Y1, and the first secondary discharge section 133 passes through the first main body 11 at the first secondary discharge end; along the third direction Z1, the middle transition section 132 and the first secondary discharge section 133 both pass through the first main body 11, the first secondary feed port and the front transition section 131 are both located on the first surface of the first main body 11, and the rear transition section 134 is located on the second surface of the first main body 11; along the second direction Y1, the middle transition section 132 and the first secondary discharge section 133 are located on both sides of the adjustment groove 1211.

[0082] When coating the positive electrode sheet, the slurry of the first secondary flow channel 13 enters the first secondary feed port from the first surface of the first main body 11, then enters the middle transition section 132 from the front transition section 131, enters the rear transition section 134 from the middle transition section 132, enters the first secondary discharge section 133 from the rear transition section 134, and is finally squeezed out from the first secondary discharge end.

[0083] In the technical scheme of the above embodiment, the first auxiliary feed port and the front transition section 131 are both located on the first surface of the first main body 11, the rear transition section 134 is located on the second surface of the first main body 11, and the middle transition section 132 runs through the first main body 11, so as to realize the change of the slurry flow path, so that the slurry can enter the first auxiliary flow channel 13 from the first surface of the first main body 11, and the first auxiliary flow channel 13 can avoid the regulating groove 1211, and the first auxiliary flow channel 13 and the regulating groove 1211 do not interfere with each other.

[0084] In some embodiments of the present application, Figure 5 As shown, the first secondary discharge section 133 includes a secondary thinning area 1333 and a secondary coating area 1332 ; along the first direction X1 , the secondary thinning area 1333 is located on a side close to the first main flow channel 12 , and the secondary coating area 1332 is located on a side away from the first main flow channel 12 .

[0085] Along the first direction X1, the secondary coating area 1332 and the secondary thinning area 1333 are arranged side by side, the secondary thinning area 1333 is close to the first main flow channel 12, and the secondary coating area 1332 is far away from the first main flow channel 12, and the thickness of the slurry extruded from the secondary thinning area 1333 is less than the thickness of the slurry extruded from the secondary coating area 1332. Both the secondary coating area 1332 and the secondary thinning area 1333 are grooves formed on the first body 11 along the third direction Z1, and the depth of the coating area is greater than the depth of the secondary thinning area 1333.

[0086] In the technical solution of the above embodiment, the first auxiliary discharge end is provided with an auxiliary thinning zone 1333 on the side close to the first main channel 12, which can reduce the accumulation of slurry, thereby effectively improving the bulging formed by the surface tension at the junction of the insulating material and the positive electrode active material, and improving the coating quality.

[0087] In some embodiments of the present application, Figure 5 As shown, along the third direction Z1 , the secondary thinning area 1333 is located on the first surface, and the secondary coating area 1332 passes through the first body 11 .

[0088] Along the third direction Z1 , the auxiliary thinning area 1333 is a groove formed on the first body 11 and does not pass through the first body 11 ; the auxiliary coating area 1332 is a through groove on the first body 11 and passes through the first body 11 along the third direction Z1 .

[0089] In the technical solution of the above embodiment, the auxiliary thinning area 1333 is located on the first surface of the first body 11, and only a groove needs to be processed on the first body 11, which is convenient for processing the first gasket 1. The auxiliary coating area 1332 runs through the first body 11, which can make the insulating material cover more fully during coating.

[0090] In some embodiments of the present application, Figure 5As shown, along the first direction X1, the length of the secondary thinning area 1333 is greater than the length of the secondary coating area 1332.

[0091] Along the first direction X1, in the length of the first secondary discharge section 133, the proportion of the secondary thinning area 1333 is greater than that of the secondary coating area 1332. During coating, the slurry extruded from the secondary thinning area 1333 covers the lower coating layer, and the slurry extruded from the secondary coating area 1332 adheres to the side wall of the lower coating layer.

[0092] In the technical solution of the above embodiment, the length of the secondary thinning zone 1333 is greater than the length of the secondary coating zone 1332, which can not only improve the structural strength of the first main body 11 at the first secondary discharge section 133, but also reduce the accumulation of the slurry extruded from the first secondary flow channel 13 on the positive electrode sheet, and also enable the slurry extruded from the first secondary flow channel 13 to cover the lower coating.

[0093] In some embodiments of the present application, Figure 4 and Figure 5 As shown, the first main discharge section 122 includes a main thinning area 1221 and a main coating area 1222; along the first direction X1, the main thinning area 1221 is located at both ends of the first main discharge section 122, and the main coating area 1222 is located between the two main thinning areas 1221; along the third direction Z1, the main thinning area 1221 is located on the first surface, and the main coating area 1222 passes through the first body 11.

[0094] Each first main discharge section 122 includes two main thinning areas 1221 and one main coating area 1222. Along the first direction X1, the main coating area 1222 is located between the two main thinning areas 1221. The main thinning area 1221 is a groove formed on the first surface.

[0095] In the technical solution of the above embodiment, the first main discharge section 122 is provided with main thinning areas 1221 on both sides of the main coating area 1222, which can reduce the accumulation of the slurry extruded from the first main flow channel 12 at both ends when coating the positive electrode sheet, thereby improving the coating quality. In addition, the main thinning area 1221 and the auxiliary thinning area 1333 are both located on the first surface of the first main body 11, which can also reduce the stress on the first main body 11 due to the processing of the first main flow channel 12 and the first auxiliary flow channel 13, and improve the stress on the first main body 11.

[0096] In some embodiments of the present application, Figure 5 As shown, along the second direction Y1, the first secondary discharge section 133 is expanded, the cross-sectional area of ​​the secondary thinning area 1333 gradually increases, and the secondary coating area 1332 extends away from the first main flow channel 12.

[0097] Along the second direction Y1, the cross-sectional area of ​​the first secondary discharge section 133 gradually increases, and correspondingly, the cross-sectional area of ​​the secondary thinning area 1333 gradually increases, and the secondary coating area 1332 gradually moves away from the first main channel 12. The cross-sectional area of ​​the secondary coating area 1332 can increase or remain unchanged.

[0098] In the technical solution of the above embodiment, the first auxiliary discharge section 133 is flared, the cross-sectional area of ​​the auxiliary thinning zone 1333 gradually increases, and the auxiliary coating zone 1332 gradually moves away from the first main channel 12. When the slurry flows, the slurry coating thickness can be thinned to improve the coating quality.

[0099] In some embodiments of the present application, Figure 5 As shown, the first secondary discharge section 133 also includes a convergence zone 1331 ; along the second direction Y1 , the convergence zone 1331 is located between the rear transition section 134 and the secondary thinning zone 1333 , and the cross-sectional area of ​​the convergence zone 1331 is greater than the sum of the cross-sectional areas of the secondary thinning zone 1333 and the secondary coating zone 1332 .

[0100] In the first secondary flow channel 13, when the slurry enters the first secondary discharge section 133 from the rear transition section 134, it first enters the convergence area 1331, and after filling the convergence area 1331, it enters the secondary thinning area 1333 and the secondary coating area 1332, and then is extruded from the first secondary discharge end.

[0101] In the technical solution of the above embodiment, the first secondary discharge section 133 is provided with a convergence area 1331, so that the slurry can first fill the convergence area 1331 and then be extruded from the first secondary discharge end. The setting of the convergence area 1331 can improve the continuity of the slurry, thereby improving the coating quality.

[0102] In some embodiments of the present application, Fig.11 As shown, the thickness of the second body 41 is greater than that of the first body 11; the thickness of the first body 11 ranges from 0.4 mm to 1 mm; the thickness of the second body 41 ranges from 0.6 mm to 1.4 mm.

[0103] Exemplarily, the thickness of the first body 11 can be 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or any intermediate value between any two adjacent values ​​mentioned above; the thickness of the second body 41 can be 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or any intermediate value between any two adjacent values ​​mentioned above.

[0104] When the first gasket 1 and the second gasket 4 are used together to coat the positive electrode sheet, the thickness of the lower coating accounts for two-thirds of the sum of the upper coating and the lower coating. The thickness of the upper coating is less than the thickness of the lower coating.

[0105] In the technical solution of the above embodiment, the thickness of the second body 41 is greater than that of the first body 11. When coating the positive electrode plate, the thickness of the upper coating layer can be reduced, thereby reducing the risk of the insulating material slurry being damaged in subsequent processes.

[0106] The inventors have found that due to the material characteristics of the insulating material, when the thickness is greater than 30μm, it is easy to crack, fall off, burst, etc. after being passed through an oven and cold pressed, and there is a risk of damage. Therefore, the thickness of the insulating material set on the positive electrode plate should not exceed 30μm. The positive electrode active material does not have the above risks. On this basis, if the coating quality of the insulating material is taken into account, the thickness of the positive electrode active material on the positive electrode plate will be greater than the thickness of the insulating material. The two have a thickness difference on the substrate of the positive electrode plate, and there will still be stress problems. In response to this, the inventors provide an improvement plan for the negative electrode plate.

[0107] In some embodiments of the present application, Figures 14 to 17 As shown, it also includes a third gasket 6, which includes a third body 61. The third body 61 is provided with a third flow channel 62, and the third flow channel 62 is provided with a third discharge end; the length of the third discharge end along the fourth direction X2 is L5, and L5=L2.

[0108] When coating the negative electrode sheet, the third gasket 6 is installed on the coating die head of the coating device, and the insulating material can be coated on the negative electrode sheet. Specifically, the third flow channel 62 is used to receive the insulating material from the coating die head and coat the insulating material on the negative active material of the negative electrode sheet.

[0109] The insulating material coated on the negative electrode plate can be the same as the insulating material coated on the positive electrode plate, or it can be different. For example, the insulating material coated on the negative electrode plate can be a low-capacity dielectric such as silicon, silicon carbide, graphite silicon, etc., which reduces the release of lithium ions. The coating thickness is supplemented according to the coating thickness difference on the positive electrode plate to achieve a uniform thickness support effect.

[0110] In the technical solution of the above embodiment, the third flow channel 62 is used to receive the slurry from the coating die head and extrude the slurry from the third discharge end. The slurry is an insulating material and is coated on the negative active material of the negative electrode sheet. The third gasket 6 is coated with insulating material on the negative electrode sheet, and L5=L2, so the coated insulating material can compensate for the thickness difference between the positive active material and the insulating material on the positive electrode sheet, and at least partially improve the stress of the positive electrode sheet.

[0111] In some embodiments of the present application, Fig.15 and Fig.16 As shown, along the fourth direction X2, the third flow channels 62 are arranged in pairs and are symmetrically distributed on the third body 61; along the fourth direction X2, the interval between the two third discharge ends is L6, L6=L3+2×L1.

[0112] The third flow channels 62 are arranged in pairs and symmetrically distributed, each third flow channel 62 is independently arranged, and multiple third flow channels 62 do not interfere with each other. On the third body 61, the number of the third flow channels 62 can be two, or an even number greater than two, and the number of the third flow channels 62 is equal to the number of the first secondary flow channels 13.

[0113] In the technical solution of the above embodiment, L6=3+2×L1, so the spacing between the two insulating material coatings on the negative electrode plate is equal to the spacing between the two insulating material coatings on the positive electrode plate. The negative electrode plate can support the positive electrode plate, compensate for the thickness difference between the positive electrode active material and the insulating material on the positive electrode plate, and improve stress.

[0114] In some embodiments of the present application, Figures 15 to 17 As shown, the third flow channel 62 includes a third feed section 621, a transmission section 622 and a third discharge section 623; the third feed section 621 is communicated with one end of the transmission section 622, the other end of the transmission section 622 is communicated with the third discharge section 623, and the third discharge section 623 penetrates the third body 61 at the third discharge end; along the fifth direction Z2, the third feed section 621 and the transmission section 622 are both located on a surface of the third body 61, and the third discharge section 623 penetrates the third body 61; the fourth direction X2 intersects with the fifth direction Z2.

[0115] When coating the negative electrode sheet, the slurry enters the third flow channel 62 from the third feed section 621, then passes through the transmission section 622 and the third discharge section 623 in sequence, and is extruded at the third discharge end. The third feed section 621 and the transmission section 622 are both grooves formed by concave and concave on one surface of the third body 61. The third discharge section 623 is a through groove on the third body 61. The fourth direction X2 can be along the length direction of the third gasket 6, and the fifth direction Z2 can be along the thickness direction of the third gasket 6.

[0116] In the technical solution of the above embodiment, the third feed section 621 and the transmission section 622 are both located on one surface of the third body 61, so the third flow channel 62 is semi-enclosed at the third feed section 621 and the transmission section 622, which can reduce the contamination of the coating die by the slurry. The third discharge section 623 runs through the third body 61, which can increase the flow rate of the slurry at the third discharge end.

[0117] In some embodiments of the present application, Fig.16As shown, along the sixth direction Y2, the third discharge section 623 includes an accumulation section 6231 and an extrusion section 6232 that are connected to each other; along the sixth direction Y2, the cross-sectional area of ​​the extrusion section 6232 gradually increases, and the cross-sectional area of ​​the accumulation section 6231 is greater than the cross-sectional area of ​​the extrusion section 6232; the fourth direction X2, the fifth direction Z2, and the sixth direction Y2 are perpendicular to each other.

[0118] When the slurry enters the third discharge section 623, it first enters the accumulation section 6231, fills the accumulation section 6231, enters the extrusion section 6232, and is extruded from the third discharge end. Along the sixth direction Y2, the extrusion section 6232 is flared. The cross-sectional area of ​​the accumulation section 6231 is greater than the cross-sectional area of ​​any point on the extrusion section 6232.

[0119] In the technical solution of the above embodiment, the third discharge section 623 is provided with an accumulation section 6231, which allows the slurry to accumulate in the accumulation section 6231 and then enter the extrusion section 6232. The accumulation section 6231 can play a buffering role on the third flow channel 62 to reduce the occurrence of breakage during coating. The cross-sectional area of ​​the extrusion section 6232 gradually increases along the sixth direction Y2, so the slurry coating thickness can be reduced, which is convenient for the slurry to be coated on the negative electrode active material.

[0120] In some embodiments of the present application, Fig.14 As shown, the thickness of the third body 61 ranges from 0.4 mm to 1.4 mm.

[0121] Exemplarily, the thickness of the third body 61 may be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, or 1.4 mm, or any intermediate value between any two adjacent values ​​mentioned above.

[0122] In the technical solution of the above embodiment, the thickness range of the third body 61 is relatively large, and can be flexibly designed.

[0123] In a second aspect, some embodiments of the present application provide a coating device, which includes a coating die and a coating gasket assembly provided by the above technical solution; the coating gasket assembly is used to be installed on the coating die.

[0124] For example, Figure 7 and Figure 8As shown, the coating die head may include an upper die head 2, a middle die head 3 and a lower die head 5, wherein the middle die head 3 is arranged between the upper die head 2 and the lower die head 5, the upper die head 2 is hingedly connected to the middle die head 3, and the middle die head 3 is hingedly connected to the lower die head 5. Any gasket in the coating gasket assembly can be clamped between the upper die head 2 and the middle die head 3; any gasket in the coating gasket assembly can be clamped between the middle die head 3 and the lower die head 5. An upper distribution cavity is provided on the upper surface of the middle die head 3, and a lower distribution cavity is provided on the upper surface of the lower die head 5. Both the upper distribution cavity and the lower distribution cavity are used to distribute the slurry.

[0125] Among the upper die head 2, the middle die head 3 and the lower die head 5 of the coating die head, the three can be used at the same time, and double-layer coating can be achieved when used at the same time, for example, the first gasket 1 is installed between the upper die head 2 and the middle die head 3, and the second gasket 4 is installed between the middle die head 3 and the lower die head 5; the three can also be used as two adjacent ones, for example, using the upper die head 2 and the middle die head 3 to achieve single-layer coating, and using the middle die head 3 and the lower die head 5 to achieve single-layer coating, which is more convenient to use.

[0126] Exemplarily, when the coating die is used together with the first gasket 1 and the second gasket 4, the slurry (positive electrode active material) enters through the middle die 3 and the lower die 5, and the slurry (insulating material) reaches the first gasket 1 through the insulating channel above the upper die 2, and is coated on the lower coating layer coated by the lower die 5 together with the slurry of the middle die 3. The upper die 2 can protrude 0.5mm from the lip, so that the gap between the two layers of slurry can be adjusted within the range value during coating.

[0127] In the technical solution of the above embodiment, the coating device has all the beneficial effects of the coating gasket assembly in any embodiment of the first aspect mentioned above. For details, please refer to the specific description of the coating gasket assembly in the above embodiments, and this embodiment will not be repeated here.

[0128] In some embodiments of the present application, the coating gasket assembly includes a first gasket 1, a second gasket 4 and a third gasket 6, the first gasket 1 is provided with a first main flow channel 12, two first secondary flow channels 13, the second gasket 4 is provided with a second flow channel 42, and the third gasket 6 is provided with two third flow channels 62. The first gasket 1 and the second gasket 4 are used in conjunction to perform double-layer coating on a single side of the positive electrode plate. After coating, a lower coating and an upper coating are formed on the positive electrode plate, and the two ends of the upper coating along the first direction X1 are insulating materials, and the insulating material covers the upper part and the side wall of the end of the lower coating. On the positive electrode plate, the thickness of the lower coating is greater than the thickness of the upper coating, and the thickness of the positive active material is greater than the thickness of the insulating material, that is, the thickness of the insulating material at the two ends of the positive electrode plate along the first direction X1 becomes smaller. On the positive electrode plate, the coating thickness of the insulating material does not exceed 30μm, achieving the improvement of the support thickness while satisfying the insulation effect. The third gasket 6 is used alone, and insulating material can be coated on the negative active material of the negative electrode sheet again after the negative electrode sheet is rolled up, thereby forming two protrusions formed of insulating material on the negative electrode sheet. When the positive electrode sheet, the negative electrode sheet and the diaphragm are assembled, the two protrusions correspond to two areas on the positive electrode sheet where the thickness becomes smaller, thereby adjusting the supporting force between the positive electrode sheet and the negative electrode sheet, improving the stress between the electrodes, reducing the liberation of lithium ions, and after forming a battery cell, the reliability of the battery cell can be improved and the service life of the battery cell can be increased.

[0129] For example, Fig.18 As shown, the positive electrode sheet coated with the first gasket 1 and the second gasket 4, and the negative electrode sheet coated with the third gasket 6 can form the electrode body of the battery cell. Fig.18 , Fig.18The disassembly diagram of the electrode body provided in some embodiments of the present application. The electrode body includes a separator 7, a first electrode sheet 8 (negative electrode sheet) and a second electrode sheet 9 (positive electrode sheet). The first electrode sheet 8 includes a first substrate 81, a first protrusion 82 and a first film layer 83. The first protrusion 82 and the first film layer 83 are symmetrically distributed on the upper and lower sides of the first substrate 81. The first protrusion 82 is formed by coating an insulating material on the first electrode sheet 8 using a third gasket 6. The second electrode sheet 9 includes a second substrate 91, a second protrusion 92, a second lower film layer 93 and a second upper film layer 94. The second protrusion 92, the second lower film layer 93 and the second upper film layer 94 are symmetrically distributed on the upper and lower sides of the second substrate 91. The second lower film layer 93 is formed by coating a positive electrode active material on the second electrode sheet 9 using a second gasket 4. The second upper film layer 94 is formed by coating a positive electrode active material on the second electrode sheet 9 using a first gasket 1, and the positive electrode active material is extruded from the first main discharge end. The second protrusion 92 is formed by coating the insulating material on the second electrode sheet 9 using the first gasket 1, and the insulating material is extruded from the first auxiliary discharge end. In the electrode body, the negative electrode sheet and the positive electrode sheet can meet the support effect, thereby reducing the capacity abnormality or short circuit problem caused by lithium deposition, reducing the risk of thermal runaway of the battery cell, and improving the reliability of the use of the battery cell.

[0130] 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 gasket assembly, characterized in that: include: A first gasket, the first gasket comprising a first main body, the first main body being provided with a first main flow channel and a first secondary flow channel, the first main flow channel penetrating the first main body at a first main discharge end, and the first secondary flow channel penetrating the first main body at a first secondary discharge end; A second gasket, the second gasket comprising a second body, the second body being provided with a second flow channel, the second flow channel penetrating the second body at a second discharge end; Along the first direction, the interval between the first main discharge end and the first auxiliary discharge end is L1, the length of the first auxiliary discharge end is L2, the length of the first main discharge end is L3, and the length of the second discharge end is L4, L3<L4, L4<L1+L2+L3.

2. The coating gasket assembly according to claim 1, characterized in that: On the first main body, the ratio of the number of the first main flow channel to the number of the first secondary flow channel is 1:2; Along the first direction, two first secondary flow channels are symmetrically arranged on both sides of each first main flow channel, and L3<L4, L4<2×(L1+L2)+L3.

3. The coating gasket assembly according to claim 2, characterized in that: Along the first direction, the difference between 2×( L1 + L2 ) + L3 and L4 ranges from 1 mm to 2 mm.

4. The coating gasket assembly according to claim 1, characterized in that: Along the first direction, L1<L2, L2<L3.

5. The coating gasket assembly according to claim 1, characterized in that: The first main flow channel comprises a first main feed section and a first main discharge section which are sequentially connected along the second direction, and the first main discharge section penetrates the first main body at the first main discharge end; Along the first direction, adjustment grooves are provided on both sides of the first main feeding section, and the adjustment grooves are located on the first surface of the first main body and communicate with the first main feeding section; Along the third direction, the first main flow channel penetrates the first main body, and the depth of the adjustment groove is less than the depth of the first main feeding section; The first direction, the second direction, and the third direction are perpendicular to each other.

6. The coating gasket assembly according to claim 5, characterized in that: The first secondary flow channel comprises a first secondary feed port, a front transition section, a middle transition section, a rear transition section and a first secondary discharge section which are sequentially connected along the second direction, and the first secondary discharge section penetrates the first main body at the first secondary discharge end; Along the third direction, the middle transition section and the first auxiliary discharge section both pass through the first main body, the first auxiliary feed port and the front transition section are both located on the first surface of the first main body, and the rear transition section is located on the second surface of the first main body; Along the second direction, the middle transition section and the first auxiliary discharge section are located on both sides of the adjustment groove.

7. The coating gasket assembly according to claim 6, characterized in that: The first secondary discharge section includes a secondary thinning zone and a secondary coating zone; Along the first direction, the auxiliary thinning area is located at a side close to the first main flow channel, and the auxiliary coating area is located at a side away from the first main flow channel.

8. The coating gasket assembly according to claim 7, characterized in that: Along the third direction, the secondary thinning area is located on the first surface, and the secondary coating area penetrates through the first body.

9. The coating gasket assembly according to claim 8, characterized in that: Along the first direction, a length of the secondary thinning region is greater than a length of the secondary coating region.

10. The coating gasket assembly according to claim 8, characterized in that: The first main discharge section includes a main thinning zone and a main coating zone; Along the first direction, the main thinning zone is located at two ends of the first main discharge section, and the main coating zone is located between the two main thinning zones; Along the third direction, the main thinning area is located on the first surface, and the main coating area passes through the first body.

11. The coating gasket assembly according to claim 8, characterized in that: Along the second direction, the first auxiliary discharge section is arranged in a flared manner, the cross-sectional area of ​​the auxiliary thinning zone gradually increases, and the auxiliary coating zone extends away from the first main flow channel.

12. The coating gasket assembly according to claim 8, characterized in that: The first secondary discharge section also includes a convergence zone; Along the second direction, the convergence zone is located between the rear transition section and the secondary thinning zone, and a cross-sectional area of ​​the convergence zone is greater than a sum of cross-sectional areas of the secondary thinning zone and the secondary coating zone.

13. The coating gasket assembly according to claim 1, characterized in that: The thickness of the second body is greater than the thickness of the first body; The thickness of the first body ranges from 0.4 mm to 1 mm; The second body has a thickness ranging from 0.6 mm to 1.4 mm.

14. The coating gasket assembly according to claim 1, characterized in that: It also includes a third gasket, the third gasket includes a third body, the third body is provided with a third flow channel, and the third flow channel is provided with a third discharge end; The length of the third discharge end along the fourth direction is L5, and L5=L2.

15. The coating gasket assembly according to claim 14, characterized in that Along the fourth direction, the third flow channels are arranged in pairs and are symmetrically distributed on the third body; Along the fourth direction, the interval between the two third discharge ends is L6, L6=L3+2×L1.

16. The coating gasket assembly according to claim 14, characterized in that The third flow channel includes a third feeding section, a transmission section and a third discharging section; The third feeding section is communicated with one end of the transmission section, the other end of the transmission section is communicated with the third discharging section, and the third discharging section penetrates the third body at the third discharging end; Along the fifth direction, the third feeding section and the transmission section are both located on one surface of the third main body, and the third discharging section passes through the third main body; The fourth direction intersects the fifth direction.

17. The coating gasket assembly according to claim 16, characterized in that Along the sixth direction, the third discharging section includes an accumulation section and an extrusion section that are connected to each other; Along the sixth direction, the cross-sectional area of ​​the extrusion section gradually increases, and the cross-sectional area of ​​the accumulation section is larger than the cross-sectional area of ​​the extrusion section; The fourth direction, the fifth direction, and the sixth direction are perpendicular to each other.

18. The coating gasket assembly according to claim 14, characterized in that The thickness of the third body ranges from 0.4 mm to 1.4 mm.

19. A coating device, characterized in that: include: A coating die and a coating gasket assembly as claimed in any one of claims 1 to 18; The coating gasket assembly is used for being installed on the coating die head.

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