Coating die head and coating machine

Abstract

The utility model discloses a coating die and a coating machine, wherein the coating die comprises: a first die, a second die and a first gasket, wherein the first die, the second die and the first gasket enclose a first coating slit and a first coating lip; a first feed port is provided on the second die, and the first feed port is suitable for introducing a first slurry into the first coating slit; a first flow channel is provided on both sides of the first coating slit on the first gasket; a second flow channel is provided on the first gasket on the side of the first flow channel away from the first coating slit; a first feeding component is provided on the first die, and is suitable for introducing a second slurry into the first flow channel and coating the edges on both sides of the first slurry; a glue dispensing component is provided on the first die, and is suitable for introducing a third slurry into the second flow channel and coating the edges of the second slurry. The utility model solves the technical problem that the slurry of the existing coating die is prone to "thick edge" phenomenon after being extruded onto the substrate, which affects the performance of the electrode sheet.

Description

Technical Field

[0001] The utility model relates to the technical field of coating machines and coating machine accessories, in particular to a coating die head and a coating machine. Background Art

[0002] In the battery production process, due to the fluid characteristics of the slurry, the sudden increase in thickness at the edge of the pole piece is called the "thick edge" phenomenon. The film coated on the edge of the battery will be thicker than other parts, resulting in uneven thickness in various parts of the battery. After the pole piece with thick edge defects is pressed in the later stage, it will show more serious warping phenomenon, which will affect the battery performance. Therefore, thinning the edge of the battery can reduce the impact of the edge effect on the battery performance and improve the cycle life and energy density of the battery.

[0003] The existing coating die head usually includes an upper die head, a lower die head and a gasket sandwiched therein. The lower die head has a semicircular long cavity, and the gasket has a notch. The notch is sandwiched between the upper die head and the lower die head to form a coating channel. After the slurry enters the cavity from the feed port, it is extruded along the coating channel and attached to the substrate. After drying, it forms an electrode sheet. Therefore, after the slurry is extruded onto the substrate through the coating channel, a "thick edge" phenomenon is likely to occur at the edge, affecting the performance of the formed electrode sheet. Utility Model Content

[0004] The utility model provides a coating die head and a coating machine, which solves the technical problem that after the slurry of the existing coating die head is extruded onto a substrate through a coating channel, a "thick edge" phenomenon easily occurs at the edge, which affects the performance of the formed electrode sheet.

[0005] In view of this, the first aspect of the present invention provides a coating die head, comprising:

[0006] The first die head;

[0007] A second die head is connected to the first die head, a first gasket is sandwiched between the first die head and the second die head, and the first die head, the second die head and the first gasket enclose a first coating slit; the first die head and the second die head form a first coating lip at the outlet end of the first coating slit; a first feed port connected to the first coating slit is provided on the second die head, the first feed port is suitable for introducing a first slurry into the first coating slit, and the first slurry is coated on the substrate through the first coating lip; first flow channels are provided on both sides of the first coating slit on the first gasket; a second flow channel is provided on the first gasket on the side of the first flow channel away from the first coating slit; wherein the outlet ends of the first flow channel and the second flow channel are both connected to the first coating lip;

[0008] A first feeding component is disposed on the first die head, and a discharge end of the first feeding component is connected to a feed end of the first flow channel, and is suitable for introducing a second slurry into the first flow channel and coating the second slurry on both side edges of the first slurry;

[0009] The dispensing component is arranged on the first die head, and the dispensing end of the dispensing component is connected with the feeding end of the second flow channel, suitable for introducing the third slurry into the second flow channel and coating the third slurry on the edge of the second slurry.

[0010] Optionally, a portion of the first gasket located between the first flow channel and the first coating slit is a first partition, and a width of an end of the first partition close to the first coating lip gradually decreases from inside to outside.

[0011] Optionally, a portion of the first gasket located between the first flow channel and the second flow channel is a second partition, and a width of the second partition at one end close to the first coating lip gradually decreases from inside to outside.

[0012] Optionally, the first feeding assembly includes two groups of first feeding parts, and the two groups of first feeding parts are respectively arranged corresponding to the two first flow channels; each group of the first feeding parts includes a first feeding rod and a first switching valve; the discharge end of the first feeding rod extends into the first die head and is connected with the feed end of the first flow channel; the feed end of the first feeding rod is connected with the first switching valve.

[0013] Optionally, a mounting hole adapted to the first feeding rod is provided in the first die head, and is suitable for mounting the first feeding rod.

[0014] Optionally, a first ball valve is provided on the first feeding rod, and the first ball valve is suitable for adjusting the flow rate of the second slurry passing into the first feeding rod.

[0015] Optionally, the dispensing assembly includes two second switch valves, and two first channels are provided in the first die head; the discharge ends of the two first channels are respectively connected to the feed ends of the two second flow channels; the feed ends of the two first channels are respectively connected to the two second switch valves, and the second switch valves are suitable for adjusting the flow rate of the third slurry passing into the first channel.

[0016] Optionally, it also includes a third die head, which is connected to the side of the second die head facing away from the first die head, and a second gasket is sandwiched between the second die head and the third die head; the second die head, the third die head and the second gasket are combined to form a second coating slit; the second die head and the third die head form a second coating lip at the outlet end of the second coating slit; the third die head is provided with a second feed port connected to the second coating slit.

[0017] Optionally, a second feeding assembly is provided on the second die head; the second feeding assembly and the first feeding assembly adopt the same structure, and the second gasket and the first gasket adopt the same structure; the discharge end of the second feeding assembly is connected to the feed end of the first flow channel on the second gasket.

[0018] A second aspect of the utility model provides a coating machine, comprising a coating die head as described in any one of the first aspects.

[0019] The technical solution of the utility model has the following advantages:

[0020] In the utility model, during coating, the first slurry, the second slurry and the third slurry are introduced at the same time, the first slurry flows out onto the substrate through the first feed port, the first coating slit and the first coating lip in sequence; the second slurry passes through the first feeding component, the first flow channel and the first coating lip in sequence and is coated onto the substrate, and is located at the two side edges of the first slurry and contacts with the first slurry, by controlling the amount of the second slurry introduced so that the amount of the second slurry is less than the amount of the first slurry at the edge, when the first slurry has a "thick edge" phenomenon due to its fluid properties, the second slurry supplements the edge of the first slurry, because the amount of the second slurry is smaller than the amount of the first slurry at the edge, therefore, after the second slurry contacts the thickened part at the edge of the first slurry, the first slurry flows to supplement the second slurry, and then the thickness of the second slurry increases while the amount of the slurry at the edge of the first slurry is weakened, thereby reducing the edge thickness of the first slurry on the substrate, or the second slurry with a surfactant is introduced to combine with the edge of the first slurry, thereby solving the problem of the first slurry having a "thick edge". The drum edge problem and the adjustment difficulty of the feeding component are reduced. Both methods can reduce the edge surface tension of the first slurry, reduce the stress concentration of the edge active material, reduce the battery edge effect, solve the edge drum edge phenomenon, make the overall thickness uniformly distributed, and improve the coating effect; the third slurry is coated on the substrate through the dispensing component, the second flow channel and the first coating lip in sequence; by arranging the first flow channel and the second flow channel on the first gasket, and supplementing the second slurry to the edge of the first slurry through the first flow channel, the "thick edge" phenomenon is eliminated, and the uniformity of the slurry coated on the substrate is improved. At the same time, the first flow channel, the second flow channel and the first coating slit are not connected to each other, so as to avoid the first slurry, the second slurry and the third slurry from mixing in advance before flowing to the first coating lip, resulting in the mixed slurry being coated on the substrate. When the "thick edge" phenomenon cannot be eliminated, the control effect of the thickness of the second slurry coated on the substrate is improved, thereby improving the adjustment effect of the edge thickness of the first slurry by the second slurry, improving the adjustment accuracy, and ensuring the uniformity of the thickness of the positive and negative electrode coatings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 A schematic diagram of the structure of a coating die head provided by the utility model at a first viewing angle;

[0023] Figure 2 for Figure 1AA section view in;

[0024] Figure 3 for Figure 1 A cross-sectional view of the first feeding assembly is not provided at BB in the figure;

[0025] Figure 4 for Figure 1 CC section view in;

[0026] Figure 5 A schematic diagram of the structure of a coating die head provided by the utility model at a second viewing angle;

[0027] Figure 6 for Figure 5 An exploded view of a coating die head;

[0028] Figure 7 This is a front structural schematic diagram of the first gasket provided by the utility model;

[0029] Figure 8 for Figure 7 Enlarged view of point D in the middle;

[0030] Fig. 9 This is a schematic diagram of the back structure of the first gasket provided by the utility model;

[0031] Fig.10 for Fig. 9 Enlarged view of point E in the middle;

[0032] Fig.11 A schematic diagram of the state of the first gasket provided by the utility model during the coating process;

[0033] Fig.12 A schematic structural diagram of a coating die head in another embodiment of the utility model at a third viewing angle;

[0034] Fig.13 for Fig.11 FF section view in;

[0035] Fig.14 The utility model provides a structural schematic diagram of a coating die head in another embodiment at a second viewing angle.

[0036] Description of reference numerals:

[0037] 1. First die; 2. Second die; 3. First gasket; 4. First coating slit; 5. First coating lip; 6. First feed port; 7. First slurry; 8. First flow channel; 9. Second flow channel; 10. First feeding assembly; 101. First feeding rod; 102. First switch valve; 103. First ball valve; 11. Second slurry; 12. Third slurry; 13. First partition; 14. Second partition; 15. Mounting hole; 16. Second switch valve; 17. First channel; 18. Third die; 19. Second gasket; 20. Second coating lip; 21. Second feed port; 22. Second feeding assembly. DETAILED DESCRIPTION

[0038] The technical solution of the utility model will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0040] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" 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 it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0041] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0042] Example 1

[0043] See also Figures 1 to 11The present embodiment provides a coating die head, comprising: a first die head 1; a second die head 2, connected to the first die head 1, a first gasket 3 sandwiched between the first die head 1 and the second die head 2, the first die head 1, the second die head and the first gasket 3 enclose a first coating slit 4; the first die head 1 and the second die head 2 form a first coating lip 5 at the outlet end of the first coating slit 4; the second die head 2 is provided with a first feed port 6 connected to the first coating slit 4, the first feed port 6 is suitable for introducing a first slurry 7 into the first coating slit 4, and the first slurry 7 is coated on the substrate through the first coating lip 5; the first gasket 3 is provided with a first flow channel 8 on both sides of the first coating slit 4; A second flow channel 9 is provided on a gasket 3 on the side of the first flow channel 8 away from the first coating slit 4; wherein the outlet ends of the first flow channel 8 and the second flow channel 9 are both connected to the first coating lip 5; a first feeding component 10 is arranged on the first die head 1, and the discharge end of the first feeding component 10 is connected to the feed end of the first flow channel 8, suitable for introducing the second slurry 11 into the first flow channel 8, and coating the second slurry 11 on both side edges of the first slurry 7; a dispensing component is arranged on the first die head 1, and the discharge end of the dispensing component is connected to the feed end of the second flow channel 9, suitable for introducing the third slurry 12 into the second flow channel 9, and coating the third slurry 12 on the edge of the second slurry 11.

[0044] It should be noted that the first slurry 7 can be a positive electrode coating slurry or a negative electrode coating slurry, the second slurry 11 is the same coating slurry as the first slurry 7, and the second slurry 11 can also be a positive electrode coating slurry or a negative electrode coating slurry with a surfactant added to facilitate mutual mixing for compensation, and the third slurry 12 is a slurry for dispensing coating.

[0045] In this embodiment, during coating, the first slurry 7, the second slurry 11 and the third slurry 12 are introduced at the same time, and the first slurry 7 flows out onto the substrate through the first feed port 6, the first coating slit 4 and the first coating lip in sequence; the second slurry 11 passes through the first feeding component 10, the first flow channel 8 and the first coating lip 5 in sequence and is coated onto the substrate, and is located at the edges of both sides of the first slurry 7 and contacts the first slurry 7. By controlling the amount of the second slurry 11 introduced, the amount of the second slurry 11 is smaller than the amount of the first slurry 7 at the edge, and the first slurry 7 is filled with liquid due to its fluid. When the "thick edge" phenomenon occurs in the characteristics, the second slurry 11 supplements the edge of the first slurry 7. Since the amount of the second slurry 11 is smaller than the amount of the slurry at the edge of the first slurry 7, after the second slurry 11 contacts the thickened part at the edge of the first slurry 7, the first slurry 7 flows to the second slurry 11 for supplementation, and then the thickness of the second slurry 11 increases while weakening the amount of slurry at the edge of the first slurry 7, thereby reducing the edge thickness of the first slurry 7 on the substrate, or introducing the second slurry 11 with a surfactant to combine with the edge of the first slurry 7, so as to solve the problem. The bulging problem of the first slurry 7 and the difficulty of adjusting the feeding component are reduced. Both methods can reduce the edge surface tension of the first slurry 7, reduce the stress concentration of the edge active material, reduce the edge effect of the battery, solve the edge bulging phenomenon, make the overall thickness evenly distributed, and improve the coating effect; the third slurry 12 is coated on the substrate through the dispensing component, the second flow channel 9 and the first coating lip 5 in sequence; by setting the first flow channel 8 and the second flow channel 9 on the first gasket 3, and replenishing the second slurry 11 to the edge of the first slurry 7 through the first flow channel 8, the "thick edge" phenomenon is eliminated , improving the uniformity of the slurry coated on the substrate. At the same time, the first flow channel 8, the second flow channel 9 and the first coating slit 4 are not connected to each other, so as to avoid the first slurry 7, the second slurry 11 and the third slurry 12 from mixing in advance before flowing to the first coating lip 5, resulting in the mixed slurry failing to eliminate the "thick edge" phenomenon when it is coated on the substrate. Therefore, the control effect of the thickness of the second slurry 11 coated on the substrate is improved, thereby improving the adjustment effect of the edge thickness of the first slurry 7 by the second slurry 11, improving the adjustment accuracy, and ensuring the uniformity of the thickness of the positive and negative electrode coatings.

[0046] Example 2

[0047] As a further improvement to Example 1, Figures 7 to 11 As shown, the portion of the first gasket 3 between the first flow channel 8 and the coating slit is the first partition 13, and the width of the first partition 13 at one end close to the first coating lip 5 gradually decreases from the inside to the outside.

[0048] In this embodiment, the width of the first partition 13 at one end close to the first coating lip 5 gradually decreases from the inside to the outside, so that a slope is formed on the side wall near the first coating slit 4 at the outlet end of the first flow channel 8, which has a diversion effect. When the second slurry 11 passes through the outlet end of the first flow channel 8, it is convenient to flow to the first slurry 7. Similarly, a slope is formed on the side wall near the first flow channel 8 at the first coating slit 4, which guides the first slurry 7 to flow to the second slurry 11, so that the first slurry 7 and the second slurry 11 are adjacent to each other when coated on the substrate, avoiding the formation of a gap between the two, thereby improving the coating effect.

[0049] Based on the above implementation, in a preferred implementation, Figures 7 to 11 As shown, the portion of the first gasket 3 between the first flow channel 8 and the second flow channel 9 is the second partition 14, and the width of the second partition 14 at one end close to the first coating lip 5 gradually decreases from the inside to the outside.

[0050] In this embodiment, the width of the second partition 14 at one end close to the first coating lip 5 gradually decreases from the inside to the outside, so that a slope is formed on the side wall on one side close to the second flow channel 9 at the outlet end of the first flow channel 8, which has a guiding effect. When the second slurry 11 passes through the outlet end of the first flow channel 8, it is convenient for the second slurry 11 to flow to the third slurry 12. Similarly, a slope is formed on the side wall on one side of the second flow channel 9 close to the first flow channel 8 to guide the third slurry 12 to flow to the second slurry 11, so that the second slurry 11 and the third slurry 12 are adjacent to each other when coated on the substrate, avoiding the formation of a gap between the two, thereby improving the coating effect.

[0051] Based on the above implementation, in a preferred implementation, Figure 5 and Figure 6 As shown, the first feeding component 10 includes two groups of first feeding parts, and the two groups of first feeding parts are respectively arranged corresponding to the two first flow channels 8; each group of first feeding parts includes a first feeding rod 101 and a first switch valve 102; the discharge end of the first feeding rod 101 extends into the first die head 1 and is connected with the feed end of the first flow channel 8; the feed end of the first feeding rod 101 is connected with the first switch valve 102, and the first switch valve 102 is suitable for adjusting the flow rate of the second slurry 11 passing into the first feeding rod 101.

[0052] It should be noted that a feeding channel for conveying the second slurry 11 is provided in the first feeding rod 101 .

[0053] In this embodiment, each first flow channel 8 is correspondingly provided with a group of first feeding parts, which are connected to an external feeding device through the first switch valve 102. At the same time, the flow rate of the second slurry 11 flowing into the first feeding rod 101 is controlled by adjusting the opening of the first switch valve 102. It can be adjusted according to actual conditions and has adjustability. The second slurry 11 passes through the first switch valve 102, the first feeding rod 101, the first flow channel 8 and the first coating lip 5 flow channel substrate in sequence.

[0054] Based on the above implementation, in a preferred implementation, Figure 5 and Figure 6 As shown, a first ball valve 103 is provided on the first feeding rod 101 , and the first ball valve 103 is suitable for adjusting the flow rate of the second slurry 11 passing into the first feeding rod 101 .

[0055] In this embodiment, a first ball valve 103 is provided on the first feeding rod 101 to adjust the flow of the second slurry 11 passing through the first feeding rod 101 to improve the adjustment accuracy. At this time, the first switch valve 102 can be used only as a conduction and closing function.

[0056] Based on the above implementation, in a preferred implementation, Figure 2 and Figure 3 As shown, a mounting hole 15 adapted to the first feeding rod 101 is provided in the first die head 1 , and is suitable for mounting the first feeding rod 101 .

[0057] In this embodiment, a mounting hole 15 is provided on the first die head 1 to facilitate the installation and disassembly of the first feeding rod 101 for cleaning and maintenance.

[0058] Based on the above implementation, in a preferred implementation, Figure 4 As shown, the dispensing assembly includes two second switch valves 16, and two first channels 17 are provided in the first die head 1; the discharge ends of the two first channels 17 are respectively connected to the feed ends of the two second flow channels 9; the feed ends of the two first channels 17 are respectively connected to the two second switch valves 16, and the second switch valves 16 are suitable for adjusting the flow rate of the third slurry 12 passing into the first channel 17.

[0059] In this embodiment, two first channels 17 are arranged in the first die head 1, and the two first channels 17 correspond to the two second flow channels 9 respectively. The external feeding equipment is connected through the second switch valve 16. At the same time, the flow rate of the third slurry 12 flowing into the first channel 17 is controlled by adjusting the opening of the second switch valve 16. It can be adjusted according to actual conditions and has adjustability. The third slurry 12 passes through the second switch valve 16, the first channel 17, the second flow channel 9 and the first coating lip 5 flow channel substrate in sequence, and a dispensing coating is applied on the edge of the second slurry 11.

[0060] Based on the above implementation, in a preferred implementation, Figure 12 to Figure 14 As shown, it also includes a third die 18, which is connected to the side of the second die 2 facing away from the first die 1, and a second gasket 19 is sandwiched between the second die 2 and the third die 18; the second die 2, the third die and the second gasket 19 are enclosed to form a second coating slit; the second die 2 and the third die 18 form a second coating lip 20 at the outlet end of the second coating slit; the third die 18 is provided with a second feed port 21 connected to the second coating slit.

[0061] In this embodiment, by setting the third die head 18, the coating die head is a double-layer coating die head, which can be applied to the double-layer coating die head. The first slurry 7 can be introduced through the second feed port 21, and the first slurry 7 is attached to the substrate through the second coating slit and the second coating lip 20. The purpose of solving the drum edge problem is achieved on the double-layer coating die head, and its application range is relatively large.

[0062] Based on the above implementation, in a preferred implementation, Figure 12 to Figure 14 As shown, a second feeding component 22 is provided on the second die head 2; the second feeding component 22 and the first feeding component 10 adopt the same structure, and the second gasket 19 and the first gasket 3 adopt the same structure; the discharge end of the second feeding component 22 is connected to the feed end of the first flow channel 8 on the second gasket 19.

[0063] In this embodiment, the second gasket 19 adopts the same structure as the first gasket 3, that is, the second gasket 19 is provided with a first flow channel 8 and a second flow channel 9 on both sides of the second coating slit, and the second feeding component 22 adopts the same structure as the first feeding component 10. The specific structure refers to the above embodiment to achieve the second slurry 11 being coated on the two side edges of the first slurry 7 through the second coating lip 20, so as to achieve the technical effect of solving the bulging edge problem when the first slurry 7 is coated on the substrate.

[0064] Specifically, Figure 12 to Figure 14As shown, the second feeding assembly 22 includes two groups of second feeding parts, and the two groups of second feeding parts are respectively arranged corresponding to the two first flow channels 8 on the second gasket 19; each group of second feeding parts includes a second feeding rod and a third switch valve; the discharge end of the second feeding rod passes through the first die head 1 and the second die head 2 and is connected to the feed end of the first flow channel 8 of the second gasket 19; the feed end of the second feeding rod is connected with the third switch valve, and the third switch valve is suitable for adjusting the flow rate of the second slurry 11 passing into the second feeding rod. It should be noted that a feeding channel for conveying the second slurry 11 is provided in the second feeding rod. Each first flow channel 8 on the second gasket 19 is correspondingly provided with a group of second feeding parts, which is connected to the external feeding equipment through the third switch valve, and the flow rate of the second slurry 11 flowing into the second feeding rod is controlled by adjusting the opening of the third switch valve, which can be adjusted according to the actual situation and has adjustability. The second slurry 11 passes through the third switch valve, the second feeding rod, the first flow channel 8 and the second coating lip 20 flow channel substrate in sequence.

[0065] Specifically, a second ball valve is provided on the second feeding rod, and the second ball valve is suitable for adjusting the flow rate of the second slurry 11 passing through the second feeding rod. By providing the second ball valve on the second feeding rod to adjust the flow rate of the second slurry 11 passing through the second feeding rod, the adjustment accuracy is improved, and at this time, the second switch valve 16 can be used only as a conduction and closing function.

[0066] Specifically, a second through hole is provided in the second die head 2 corresponding to each first through hole, a through hole is provided on the first gasket 3, the outlet end of the first through hole, the through hole and the inlet end of the second through hole are connected in sequence, and the outlet end of the second through hole is connected to the second flow channel 9 on the second gasket 19. The second through hole is connected to the first through hole, and when the third slurry 12 is input through the first through hole for dispensing, the third slurry 12 is simultaneously input to the second through hole, and then input into the second flow channel 9 of the second gasket 19 and flows out, thereby realizing the dispensing function at the second coating lip 20.

[0067] The specific working principle of a coating die head provided in this embodiment is as follows: during coating, the first slurry 7, the second slurry 11 and the third slurry 12 are introduced at the same time, and the first slurry 7 flows out onto the substrate through the first feed port 6, the first coating slit 4 and the first coating lip in sequence; the second slurry 11 passes through the first switch valve 102, the first feeding rod 101, the first flow channel 8 and the first coating lip 5 in sequence and is coated onto the substrate, and is located at the two side edges of the first slurry 7 and contacts the first slurry 7, and the slurry amount of the second slurry 11 introduced is controlled by the first ball valve 103, so that the slurry amount of the second slurry 11 is less than the slurry amount of the first slurry 7 at the edge, and the second slurry 11 is less than the slurry amount of the first slurry 7 at the edge due to its fluid characteristics. When the "thick edge" phenomenon occurs, the second slurry 11 supplements the edge of the first slurry 7. Since the amount of the second slurry 11 is smaller than the amount of the slurry at the edge of the first slurry 7, after the second slurry 11 contacts the thickened portion at the edge of the first slurry 7, the first slurry 7 flows to the second slurry 11 for supplementation, and then the thickness of the second slurry 11 increases while the amount of slurry at the edge of the first slurry 7 is weakened, thereby reducing the edge thickness of the first slurry 7 on the substrate, or introducing the second slurry 11 with a surfactant to combine with the edge of the first slurry 7, thereby solving the bulging problem of the first slurry 7 and reducing the difficulty of adjusting the feeding component. Both methods can reduce the thickness of the first slurry 7. The edge surface tension of the first slurry 7 reduces the stress concentration of the edge active material, reduces the battery edge effect, solves the edge bulging phenomenon, makes the overall thickness uniformly distributed, and improves the coating effect; the third slurry 12 is coated on the substrate through the second switch valve 16, the first channel 17, the second flow channel 9 and the first coating lip 5 in sequence; by arranging the first flow channel 8 and the second flow channel 9 on the first gasket 3, and supplementing the second slurry 11 to the edge of the first slurry 7 through the first flow channel 8, the "thick edge" phenomenon is eliminated, and the uniformity of the slurry coated on the substrate is improved. At the same time, the first flow channel 8, the second flow channel 9 and the first coating slit 4 are not connected to each other, avoiding the first slurry 7 and the second slurry 1 1 and the third slurry 12 are mixed in advance before flowing to the first coating lip 5, resulting in the mixed slurry failing to eliminate the "thick edge" phenomenon when applied to the substrate, thereby improving the control effect of the thickness of the second slurry 11 applied to the substrate, thereby improving the adjustment effect of the edge thickness of the first slurry 7 by the second slurry 11, improving the adjustment accuracy, ensuring the uniformity of the thickness of the positive and negative electrode coatings, reducing the surface tension of the slurry edge applied to the substrate, reducing the stress concentration of the edge active material, reducing the battery edge effect, solving the edge bulging phenomenon, improving the overall energy density of the battery, and improving the electrochemical performance. At the same time, it can be applied to single-layer coating dies and double-layer coating dies, with a wide range of applications. It solves the technical problem that after the slurry of the existing coating die is extruded onto the substrate through the coating channel, the "thick edge" phenomenon is easily generated at the edge, affecting the performance of the formed electrode sheet.

[0068] Example 3

[0069] A coating machine provided in this embodiment includes a coating die head as in Example 1 or Example 2. The specific structure of the coating die head is the same as that of Example 1 or Example 2, so that the coating machine having the coating die head has at least the same technical effect as the above-mentioned coating die head. The specific principle is the same as that of Example 1 or Example 2, and will not be repeated here one by one.

[0070] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention of the utility model.

Claims

1. A coating die head, characterized in that: include: A first die head (1); A second die head (2) is connected to the first die head (1); a first gasket (3) is sandwiched between the first die head (1) and the second die head (2); the first die head (1), the second die head and the first gasket (3) together form a first coating slit (4); the first die head (1) and the second die head (2) form a first coating lip (5) at the outlet end of the first coating slit (4); the second die head (2) is provided with a first feed port (6) connected to the first coating slit (4); the first feed port (6) suitable for introducing a first slurry (7) into the first coating slit (4), and the first slurry (7) is coated onto the substrate through the first coating lip (5); the first gasket (3) is provided with a first flow channel (8) on both sides of the first coating slit (4); the first gasket (3) is provided with a second flow channel (9) on the side of the first flow channel (8) away from the first coating slit (4); wherein the outlet ends of the first flow channel (8) and the second flow channel (9) are both connected to the first coating lip (5); A first feeding component (10) is arranged on the first die head (1), and the discharge end of the first feeding component (10) is connected to the feed end of the first flow channel (8), and is suitable for introducing a second slurry (11) into the first flow channel (8), and coating the second slurry (11) on both side edges of the first slurry (7); A glue dispensing component is arranged on the first die head (1), and the discharge end of the glue dispensing component is connected to the feed end of the second flow channel (9), suitable for introducing a third slurry (12) into the second flow channel (9) and coating the third slurry (12) on the edge of the second slurry (11).

2. The coating die head according to claim 1, characterized in that: The portion of the first gasket (3) located between the first flow channel (8) and the first coating slit (4) is a first partition (13), and the width of the first partition (13) at one end close to the first coating lip (5) gradually decreases from the inside to the outside.

3. The coating die head according to claim 1, characterized in that: The portion of the first gasket (3) located between the first flow channel (8) and the second flow channel (9) is a second partition (14), and the width of the second partition (14) at one end close to the first coating lip (5) gradually decreases from the inside to the outside.

4. The coating die head according to claim 1, characterized in that: The first feeding component (10) comprises two groups of first feeding parts, and the two groups of first feeding parts are respectively arranged corresponding to the two first flow channels (8); each group of the first feeding parts comprises a first feeding rod (101) and a first switch valve (102); the discharge end of the first feeding rod (101) extends into the first die head (1) and is connected to the feed end of the first flow channel (8); the feed end of the first feeding rod (101) is connected to the first switch valve (102).

5. The coating die head according to claim 4, characterized in that: The first die head (1) is provided with a mounting hole (15) adapted to the first feeding rod (101), and is suitable for mounting the first feeding rod (101).

6. The coating die head according to claim 4, characterized in that: The first feeding rod (101) is provided with a first ball valve (103), and the first ball valve (103) is suitable for adjusting the flow rate of the second slurry (11) passing into the first feeding rod (101).

7. The coating die head according to claim 1, characterized in that: The dispensing assembly comprises two second switch valves (16), and two first channels (17) are arranged in the first die head (1); the discharge ends of the two first channels (17) are respectively connected to the feed ends of the two second flow channels (9); the feed ends of the two first channels (17) are respectively connected to the two second switch valves (16), and the second switch valves (16) are suitable for adjusting the flow rate of the third slurry (12) entering the first channel (17).

8. The coating die head according to any one of claims 1 to 6, characterized in that: The invention also comprises a third die head (18), wherein the third die head (18) is connected to the side of the second die head (2) facing away from the first die head (1), and a second gasket (19) is sandwiched between the second die head (2) and the third die head (18); the second die head (2), the third die head and the second gasket (19) are enclosed to form a second coating slit; the second die head (2) and the third die head (18) form a second coating lip (20) at the outlet end of the second coating slit; and the third die head (18) is provided with a second feed port (21) connected to the second coating slit.

9. The coating die head according to claim 8, characterized in that: The second die head (2) is provided with a second feeding assembly (22); the second feeding assembly (22) and the first feeding assembly (10) have the same structure, and the second gasket (19) and the first gasket (3) have the same structure; the discharge end of the second feeding assembly (22) is connected to the feed end of the first flow channel (8) on the second gasket (19).

10. A coating machine, characterized in that: The coating die comprises a coating die as described in any one of claims 1 to 8.

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