Coating die head and coating device

Abstract

The utility model discloses a coating die head and a coating device, and belongs to the field of battery pole piece processing equipment. A coating die includes a die body and a shim assembly. The die head body comprises a die head body and a gasket; the die head body comprises a first die head and a second die head which are arranged in a stacked mode in the height direction of the die head body, and the first die head and the second die head define a containing cavity used for containing first slurry. The gasket is provided with a first side face in the height direction, the first side face is sunken to form a first groove, and the first groove and one of the first die head and the second die head define a first runner used for containing second slurry; the gasket comprises a protruding part, and the protruding part protrudes out of the bottom wall of the first groove so as to block part of the first flow channel. By adopting the coating die head with the structure, the risk that the tab is cracked when being bent due to redundancy of the cathode tab can be reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of battery pole piece processing equipment, in particular to a coating die and a coating device. BACKGROUND

[0002] Coating is an essential process in the production of batteries, mainly applied in the production of battery pole pieces. Coating in the production of pole pieces refers to the process of uniformly, continuously or intermittently coating the prepared paste-like viscous slurry on the substrate of the pole piece through the coating die through the coating opening.

[0003] When coating the cathode pole piece, the tab adhesive needs to be coated on both sides of the active material slurry, and since both slurries are coated simultaneously through the same coating die. When the coating thickness of the active material slurry increases, the coating thickness of the tab adhesive increases, which in turn causes the thickness of the tab adhesive on the cathode pole piece to be large, increasing the risk of cracking when the tab is bent due to the redundancy of the cathode tab. CONTENT OF THE UTILITY MODEL

[0004] The present application provides a coating die and a coating device, which can reduce the thickness of the tab adhesive on the cathode pole piece to reduce the risk of cracking when the tab is bent due to the redundancy of the cathode tab.

[0005] In a first aspect, the present application provides a coating die comprising a die body and a gasket; the die body comprises a first die and a second die stacked along the height direction thereof, and the first die and the second die enclose a containing cavity for containing a first slurry. The gasket has a first side surface in the height direction, which is recessed to form a first groove, and the first groove and one of the first die and the second die enclose a first flow channel for containing a second slurry; wherein the gasket comprises a protruding portion protruding from the bottom wall of the first groove to block part of the first flow channel.

[0006] In the above technical solution, the gasket comprises a protruding portion protruding from the bottom wall of the first groove, so that compared to the case where the first groove of the gasket is not provided with a protruding portion, the protruding portion occupies a certain space of the first groove, thereby reducing the cross-sectional area of the first groove, thereby reducing the flow rate of the second slurry under the condition that the flow rate of the second slurry is constant, thereby reducing the volume of the second slurry flowing out of the first flow channel when coating the cathode pole piece, thereby reducing the coating thickness of the second slurry under the condition that the width of the second slurry coating is unchanged, thereby reducing the thickness of the second slurry on the cathode pole piece, and thereby reducing the risk of cracking when the tab is bent due to the excessive thickness of the second slurry on the cathode tab.

[0007] In some embodiments, the protruding portion is a plurality of protruding portions, and the plurality of protruding portions are arranged at intervals along the length direction of the die body.

[0008] In the above technical solution, the plurality of protrusions are arranged at intervals along the length direction of the die body, so that the cross-sectional area of the first flow channel is reduced more evenly along the length direction of the die body, so that the second slurry is more evenly distributed in the first flow channel in the length direction of the die body, and then the thickness distribution of the second slurry is more uniform in the length direction of the die body when the second slurry is coated on the substrate.

[0009] In some embodiments, along the height direction, an end surface of the protrusion away from the bottom wall has a first gap with one of the first die and the second die.

[0010] In the above technical solution, the end surface of the protrusion away from the bottom wall has a first gap with one of the first die and the second die, so that the second slurry can flow out from the first gap, and the size of the second slurry flowing out through the first gap in the height direction of the die body is smaller than the size of the second slurry not flowing out through the first gap in the height direction of the die body, so that the part of the second slurry not flowing out through the first gap will flow to the direction of the second slurry flowing out through the first gap, so that the overall thickness of the second slurry is reduced, and then the thickness of the second slurry on the cathode tab is reduced, thereby reducing the risk of cracking when the tab is bent due to the excessive thickness of the second slurry on the cathode tab.

[0011] In some embodiments, the first groove has oppositely arranged first and second side walls in the length direction; one of the plurality of protrusions closest to the first side wall is a first end protrusion, and the first end protrusion has a second gap with the first side wall in the length direction; one of the plurality of protrusions closest to the second side wall is a second end protrusion, and the second end protrusion has a third gap with the second side wall in the length direction.

[0012] In the above technical solution, along the length direction, the first end protrusion has a second gap with the first side wall, and the second end protrusion has a third gap with the second side wall, so that the opposite sides of any protrusion in the length direction are provided with regions for the second slurry to pass through, so that the second slurry flowing out from the first gap has the second slurry not flowing out through the first gap on both sides in the length direction of the die body, thereby reducing the time for the second slurry not flowing out through the first gap to fill the second slurry flowing out through the first gap, and then improving the uniformity of the overall thickness of the second slurry and improving the coating quality of the second slurry.

[0013] In some embodiments, the gasket has an end surface in a width direction of the die body, the end surface having a second coating opening in communication with the first flow channel; the protrusion has a first end in the width direction facing the second coating opening, the first end having a distance H from the second coating opening in the width direction, satisfying 0mm

[0014] In the above technical solution, when H>0mm, a certain distance between the protrusion and the second coating opening in the width direction is formed, so that the second slurry not flowing through the first gap can fill the second slurry flowing through the first gap, thereby improving the uniformity of the overall thickness of the second slurry and improving the coating quality of the second slurry; when H≤2mm, the size of the first flow channel in the width direction is reduced, thereby reducing the size of the first groove in the width direction of the gasket, further reducing the weakening of the strength of the gasket by the first groove, improving the strength of the gasket, and thereby improving the reliability of the coating die; thereby, when 0mm

[0015] In some embodiments, 0.5mm≤H≤1mm.

[0016] In the above technical solution, when H>0.5mm, a certain distance between the protrusion and the second coating opening in the width direction is formed, so that the second slurry not flowing through the first gap can fill the second slurry flowing through the first gap, thereby further improving the uniformity of the overall thickness of the second slurry and improving the coating quality of the second slurry; when H≤1mm, the size of the first flow channel in the width direction is further reduced, thereby further reducing the size of the first groove in the width direction of the gasket, further reducing the weakening of the strength of the gasket by the first groove, thereby further improving the strength of the gasket, and thereby improving the reliability of the coating die; thereby, when 0.5mm

[0017] In some embodiments, the first side surface is recessed to form a second groove in communication with the first groove, the second groove being enclosed with one of the first die and the second die to form a second flow channel for accommodating the second slurry.

[0018] In the technical solution, the first groove and the second groove are communicated, and the second groove and one of the first die and the second die form a second flow channel for containing the second slurry, so that when the pressure in the first flow channel increases due to the decrease of the flow of the second slurry, the second flow channel can divert a part of the second slurry, thereby reducing the risk of deformation of the gasket due to the excessive pressure in the first flow channel, and further reducing the risk of mixing of the second slurry in the first flow channel and the first slurry in the containing cavity due to the deformation of the gasket.

[0019] In some embodiments, the size of the second flow channel in the height direction is equal to the size of the first flow channel in the height direction.

[0020] In the technical solution, the size of the second groove in the height direction is equal to the size of the first groove in the height direction, which on one hand makes the processing sizes of the second groove and the first groove the same, facilitating the processing of the gasket, and on the other hand, compared with the case that the depth of the second groove is less than that of the first groove, increases the flow of the second slurry in the second flow channel formed by the second groove, and improves the pressure relief capability of the second flow channel to the first flow channel.

[0021] In some embodiments, one side of the gasket in the width direction of the die body is recessed to form a gap, and the gap and the opposite sides of the first die and the second die form a first coating opening communicated with the containing cavity; an end surface of the gasket in the width direction has a second coating opening communicated with the first flow channel and a third coating opening communicated with the second flow channel; along the length direction of the die body, the third coating opening is located between the second coating opening and the first coating opening.

[0022] In the technical solution, on one hand, the end surface of the gasket in the width direction has the third coating opening communicated with the second flow channel, so that the second slurry in the second flow channel can also be used for coating the pole piece, reducing the waste of the second slurry and the production cost; on the other hand, along the length direction of the die body, the third coating opening is located between the second coating opening and the first coating opening, so that the second slurry coated on the substrate from the second coating opening is farther away from the first slurry than the second slurry coated on the substrate from the third coating opening, so that the second slurry coated on the substrate from the second coating opening is closer to the bending area, thereby reducing the thickness of the second slurry on the cathode pole piece near the bending area, and reducing the risk of cracking of the pole tab when the pole tab is bent due to the excessive thickness of the second slurry on the cathode pole tab.

[0023] In some embodiments, the gasket has a first through hole for the second slurry to enter the first flow channel, and one of the first die and the second die has a second through hole communicated with the first through hole.

[0024] In the technical solution, the gasket has a first through hole for the second slurry to enter the flow channel, one of the first die and the second die has a second through hole communicating with the first through hole, thereby facilitating injection of the second slurry into the first flow channel through the second through hole, and facilitating the communication of the first flow channel with the second slurry source.

[0025] In a second aspect, the embodiments of the present application further provide a coating device comprising the coating die mentioned above. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiments will be briefly introduced as follows. It should be understood that the following drawings only show some of the embodiments of the present application, and therefore should not be considered as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0027] Figure 1 Structure explosion diagram of the coating die provided by some embodiments of the present application;

[0028] Figure 2 Structure schematic diagram of the coating die provided by some embodiments of the present application;

[0029] Figure 3 Structure schematic diagram of the coating die provided by some embodiments of the present application in the A perspective view; Figure 2

[0030] Structure schematic diagram of the coating die provided by some embodiments of the present application in the A perspective view; Figure 4 Figure 2 Structure schematic diagram of the coating die provided by some embodiments of the present application in the A perspective view;

[0031] Figure 5 Figure 4 Sectional view of the B-B in the A perspective view;

[0032] Figure 6 Structure schematic diagram of the coating die provided by some embodiments of the present application in the A perspective view; Figure 2

[0033] Structure schematic diagram of the coating die provided by some embodiments of the present application in the A perspective view; Figure 7 Figure 6 Sectional view of the C-C in the A perspective view.

[0034] Figure legend: 100-coating die;

[0035] 10-die body; 10A-housing cavity; 10B-first flow channel; 10C-second flow channel; 10D-first coating port; 101-first gap; 102-second gap; 103-third gap; 11-first die; 12-second die; ​​​

[0036] 20 - spacer; 201 - first groove; 201A - first side wall; 201B - second side wall; 201C - second coating port; 201D - third coating port; 201E - third side wall; 202 - protrusion; 202A - first end protrusion; 202B - second end protrusion; 203 - second groove; 204 - notch;

[0037] X - height direction; Y - width direction; Z - length direction. DETAILED DESCRIPTION

[0038] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0039] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by one of ordinary skill in the art to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing the specific embodiments of the present application, and are not intended to limit the present application; the terms "include" and "have" and any variations thereof in the specification and claims of the present application and the above description of drawings are intended to cover non-exclusive inclusion. The terms "first", "second" and the like in the specification and claims of the present application and the above description of drawings are used to distinguish different objects, and are not intended to describe a particular order or primary and secondary relationship.

[0040] In the present application, the phrase "embodiment" means that the specific features, structures or characteristics described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at various places in the specification does not necessarily mean the same embodiment, nor is it an independent or alternative embodiment to other embodiments.

[0041] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "attach" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral connection; it can be direct connection, or indirect connection through intermediate medium; it can be internal communication of two elements. For those of ordinary skill in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0042] The term "and / or", in the present application, is merely an associated relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in the present application generally represents an "or" relationship between the front and rear associated objects.

[0043] In the embodiments of the present application, the same reference signs represent the same components, and for the sake of brevity, the detailed description of the same components is omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, and the overall thickness, length, width and other dimensions of the integrated device are only exemplary and should not constitute any limitation on the present application.

[0044] "Multiple" appearing in the present application means two or more (including two).

[0045] Coating of the pole piece refers to one of the key steps in the production process of lithium batteries, in which the prepared coating slurry is uniformly, continuously or intermittently coated on the substrate (aluminum foil or copper foil) to prepare the battery. The coating needs to ensure the thickness consistency of each coating position and control the coating thickness within the tolerance range required by the process. The quality and stability of the pole piece coating process have an important influence on the performance and cycle life of the battery.

[0046] Currently, there are two common coating methods in China: transfer coating and extrusion coating. Transfer coating is a mature technology, but its structure is complex and the equipment is difficult to debug. Moreover, the slurry of transfer coating is in a naked state (i.e. the coating slurry is exposed to the air), and the performance of the coating slurry is difficult to guarantee.

[0047] Extrusion coating machine technology is increasingly mature, which has simple structure, compact equipment and convenient debugging. In addition, the coating slurry in the coating head is in a closed state and isolated from the outside world, which can ensure the excellent variety of the coating slurry. Moreover, the coating precision of the extrusion coating type coating machine is much higher than that of the traditional transfer coating machine. The current experimental results show that the minimum thickness limit of transfer coating is 50um, while that of extrusion coating can reach 20um. Therefore, using extrusion coating machine to coat lithium ion battery pole piece and the like has become a development trend.

[0048] The coating die is an important part of the coating device, which is used to uniformly apply the coating slurry on the surface of the substrate. The coating die usually has a cavity inside to accommodate the first slurry (negative active material). The gasket of the coating die usually has a flow channel to accommodate the second slurry (tab adhesive).

[0049] As an example, the negative electrode substrate can employ a metal foil, a foamed metal, or a composite current collector. For example, as the metal foil, silver surface-treated aluminum or stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, nickel, or titanium, etc. can be employed. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (such as a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0050] As an example, the negative electrode sheet can include a negative electrode substrate and a negative electrode active material disposed on at least one surface of the negative electrode substrate.

[0051] As an example, the negative electrode substrate has two surfaces opposite in the thickness direction thereof, and the negative electrode active material is disposed on either one or both of the two opposite surfaces of the negative electrode substrate.

[0052] As an example, the negative electrode active material can employ a negative electrode active material for a battery cell known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, and lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a battery negative electrode active material can also be used. These negative electrode active materials can be used alone only one or two or more can be used in combination.

[0053] In coating the cathode electrode sheet, tab adhesive needs to be coated on both sides of the active material slurry, since both slurries are simultaneously coated through the same coating die. Therefore, in increasing the coating thickness of the negative electrode active material slurry in order to increase the energy density of the battery cell, the coating thickness of the tab adhesive also increases, and thus the thickness of the tab adhesive on the cathode electrode sheet becomes large, increasing the risk of cracking when the tab is bent due to the cathode tab redundancy.

[0054] Based on the above considerations, in order to solve the problem that when the coating thickness of the negative active material slurry is thick, the coating thickness of the tab glue is also thick, and then the thickness of the tab glue on the cathode tab is large, which increases the risk of cathode tab redundancy and causes the risk of tab cracking when the tab is bent. The application provides a coating die including a die body and a gasket; the die body includes a first die and a second die stacked in the height direction thereof, and the first die and the second die enclose a containing cavity for containing a first slurry. The gasket has a first side surface in the height direction, and the first side surface is recessed to form a first groove, and the first groove encloses one of the first die and the second die to form a first flow channel 10B for containing a second slurry; wherein the gasket includes a protruding portion protruding from the bottom wall of the first groove to block part of the first flow channel.

[0055] In the coating die of this structure, the gasket includes a protruding portion protruding from the bottom wall of the first groove, so that compared with the case where the first groove of the gasket is not provided with a protruding portion, the protruding portion occupies a certain space of the first groove, thereby reducing the cross-sectional area of the first groove, thereby reducing the flow rate of the second slurry under the condition that the flow rate of the second slurry is constant, thereby reducing the volume of the second slurry flowing out of the first flow channel when coating the cathode tab, thereby reducing the coating thickness of the second slurry under the condition that the width of the second slurry coating is unchanged, thereby reducing the thickness of the second slurry on the cathode tab, thereby reducing the risk of tab cracking when the tab is bent due to the excessive thickness of the second slurry on the cathode tab.

[0056] The specific structure of the coating die is described in detail below in conjunction with the drawings.

[0057] Please refer to Figure 1 and Figure 2 , and please refer to Figure 3 and Figure 4 , Figure 1 the structure explosion drawing of the coating die 100 provided by some embodiments of the application, Figure 2 the structure schematic diagram of the coating die 100 provided by some embodiments of the application, Figure 3 and Figure 4Two coating die 100 structure schematic diagrams under A perspective view are provided for some embodiments of the present application. The coating die 100 provided by the embodiments of the present application includes a die body 10 and a gasket 20; the die body 10 includes a first die 11 and a second die 12 which are stacked along the height direction X of the die body 10, and the first die 11 and the second die 12 enclose a containing cavity 10A for containing a first slurry. The gasket 20 has a first side surface in the height direction X, and the first side surface is recessed to form a first recess 201, and the first recess 201 encloses one of the first die 11 and the second die 12 to form a first flow channel 10B for containing a second slurry; wherein the gasket 20 includes a protruding portion 202 which protrudes from the bottom wall of the first recess 201 to block part of the first flow channel 10B.

[0058] The die body 10 is a part of the coating die 100 for uniformly applying the coating slurry to the surface of the substrate.

[0059] The first die 11 and the second die 12 are main body parts of the die body 10.

[0060] It can be understood that the first die 11 and the second die 12 are generally metal parts to have high strength and rigidity, thereby reducing the risk of deformation of the die body 10 when the containing cavity 10A has excessive pressure.

[0061] Exemplarily, the first die 11 and the second die 12 can be connected by screws, or the first die 11 and the second die 12 can be connected by buckles, or the first die 11 and the second die 12 can be clamped by clamps.

[0062] The first die 11 and the second die 12 enclose the containing cavity 10A for containing the first slurry, which can be understood as that the opposite sides of the first die 11 and the second die 12 enclose the containing cavity 10A. Exemplarily, one of the first die 11 and the second die 12 has a side surface facing the other which is recessed to form a recess, and the recess and the side surface of the other facing the recess enclose the containing cavity 10A.

[0063] If the recess is arranged on the side surface of the first die 11 facing the second die 12, the recess and the side surface of the second die 12 facing the first die 11 enclose the containing cavity 10A; if the recess is arranged on the side surface of the second die 12 facing the first die 11, the recess and the side surface of the first die 11 facing the second die 12 enclose the containing cavity 10A.

[0064] The height direction X is the direction in which the first die 11 and the second die 12 are stacked, the width direction Y and the length direction Z are directions perpendicular to the height direction X in pairs. Exemplarily, the length direction Z can be the extension direction of the longer edge of the orthographic projection of the die body 10 on a plane perpendicular to the height direction X; the width direction Y can be the extension direction of the shorter edge of the orthographic projection of the die body 10 on a plane perpendicular to the height direction X.

[0065] In some embodiments, the first slurry and the second slurry can be arranged alternately along the length direction Z.

[0066] Exemplarily, the first die 11 or the second die 12 can have a feeding port (not shown in the figure) in communication with the first accommodating cavity 10A, the feeding port (not shown in the figure) being used for the first slurry to enter the accommodating cavity 10A.

[0067] The gasket 20 is a component arranged between the first die 11 and the second die 12 to form the first flow channel 10B between the first die 11 and the second die 12.

[0068] Exemplarily, the first die 11 and the second die 12 can be surrounded by the gasket 20 to form a first coating port (not shown in the figure) in communication with the accommodating cavity 10A, the first slurry exiting the accommodating cavity 10A through the first coating port (not shown in the figure) and being coated on the substrate.

[0069] The first side can be the side of the gasket 20 facing the first die 11 in the height direction X, and the first side can also be the side of the gasket 20 facing the second die 12 in the height direction X.

[0070] The first groove 201 is a strip-shaped groove formed by recessing the first side, and exemplarily, the first groove 201 can be formed on the first side by machining methods such as turning and milling, or can be made synchronously with the first side by an integral molding method.

[0071] The first flow channel 10B is a structure for accommodating the second slurry used by the coating die 100.

[0072] The first groove 201 and one of the first die 11 and the second die 12 form the first flow channel 10B for accommodating the second slurry, which can be understood as that the first groove 201 and the side of the first die 11 facing the gasket 20 form the first flow channel 10B, or that the first groove 201 and the side of the second die 12 facing the gasket 20 form the first flow channel 10B. Please refer to Figure 3 and Figure 4 The range where the first flow channel 10B is located is identified by a dashed line in the figure, and it should be noted that the dashed line only facilitates the display of the range of the first flow channel 10B and does not represent any entity meaning.

[0073] If the first side is the side of the gasket 20 facing the first die body, the first groove 201 and the side of the first die head 11 facing the gasket 20 enclose the first flow channel 10B; if the first side is the side of the gasket 20 facing the second die body, the first groove 201 and the side of the second die head 12 facing the gasket 20 enclose the first flow channel 10B.

[0074] It can be understood that the gasket 20 is generally a metal piece to have higher strength and rigidity, so as to reduce the risk of deformation of the gasket 20 when the pressure of the first flow channel 10B is too large, thereby reducing the risk of leakage of the second slurry from the second flow channel 10C to contaminate the first slurry.

[0075] Exemplarily, one side of the gasket 20 in the width direction Y can be provided with a second coating opening (not shown in the figure) in communication with the first flow channel 10B, and the second slurry exits the first flow channel 10B through the second coating opening (not shown in the figure) and is coated on the substrate.

[0076] The protruding portion 202 is a portion of the gasket 20 protruding from the bottom wall of the first groove 201 in the height direction X. Please refer to Figure 3 and Figure 4 , the range where the protruding portion 202 is located is marked in a filled pattern in the figure, and it should be noted that the filled pattern is only for the convenience of showing the range of the protruding portion 202, and does not represent any entity meaning.

[0077] In some embodiments, please refer to Figure 3 , the protruding portion 202 can extend in the length direction Z to block part of the first flow channel 10B.

[0078] In some embodiments, please refer to Figure 4 , the protruding portion 202 can extend in the width direction Y to block part of the first flow channel 10B.

[0079] In the present embodiment, the gasket 20 includes the protruding portion 202, which protrudes from the bottom wall of the first groove 201, so that compared with the case where the protruding portion 202 is not arranged in the first groove 201 of the gasket 20, the protruding portion 202 occupies a certain space of the first groove 201, thereby reducing the cross-sectional area of the first groove 201, and under the condition that the flow rate of the second slurry is constant, the flow rate of the second slurry is reduced, thereby reducing the volume of the second slurry flowing out of the first flow channel 10B when coating the cathode tab, and under the premise that the width of the second slurry coating is unchanged, the coating thickness of the second slurry is reduced, thereby reducing the thickness of the second slurry on the cathode tab, and thereby reducing the risk of cracking when the tab is bent due to the excessive thickness of the second slurry on the cathode tab.

[0080] Please refer to Figure 4 and Figure 5 ,Figure 5 For Figure 4 A sectional view of B-B. According to some embodiments of the present application, the plurality of protrusions 202 are arranged along the length direction Z of the die body 10.

[0081] In the present embodiment, the plurality of protrusions 202 are arranged along the length direction Z of the die body 10, so that the cross-sectional area of the first flow channel 10B decreases more evenly along the length direction Z of the die body 10, so that the second slurry is more evenly distributed in the first flow channel 10B along the length direction Z of the die body 10, and then the thickness distribution of the second slurry is more uniform along the length direction Z of the die body 10 when the second slurry is coated on the substrate.

[0082] Please refer to Figure 5 According to some embodiments of the present application, the end surface of the protrusion 202 away from the bottom wall has a first gap 101 with one of the first die 11 and the second die 12 along the height direction X.

[0083] The end surface of the protrusion 202 away from the bottom wall has a first gap 101 with one of the first die 11 and the second die 12 can be understood as that the end surface of the protrusion 202 away from the bottom wall has a first gap 101 with the side surface of the first die 11 facing the gasket 20, and can also be understood as that the end surface of the protrusion 202 away from the bottom wall has a first gap 101 with the side surface of the second die 12 facing the gasket 20.

[0084] If the first groove 201 and the side surface of the first die 11 facing the gasket 20 form the first flow channel 10B, the first gap 101 is located between the end surface of the protrusion 202 away from the bottom wall and the first die 11; if the first groove 201 and the side surface of the second die 12 facing the gasket 20 form the first flow channel 10B, the first gap 101 is located between the end surface of the protrusion 202 away from the bottom wall and the second die 12.

[0085] In the present embodiment, the end surface of the protrusion 202 away from the bottom wall has a first gap 101 with one of the first die 11 and the second die 12, so that the second slurry can flow out from the first gap 101, and the size of the second slurry flowing out through the first gap 101 in the height direction of the die body 10 is smaller than the size of the second slurry not flowing out through the first gap 101 in the height direction of the die body 10, so that the part of the second slurry not flowing out through the first gap 101 will flow to the direction of the second slurry flowing out through the first gap 101, so that the thickness of the whole second slurry is reduced, and then the thickness of the second slurry on the cathode tab is reduced, so that the risk of cracking when the tab is bent due to the excessive thickness of the second slurry on the cathode tab is reduced.

[0086] Please refer toFigure 4 According to some embodiments of the present application, the first recess 201 has a first side wall 201A and a second side wall 201B oppositely arranged in the length direction Z, the first end protrusion 202A is the protrusion 202 closest to the first side wall 201A among the plurality of protrusions 202, and the second end protrusion 202B is the protrusion 202 closest to the second side wall 201B among the plurality of protrusions 202.

[0087] The first side wall 201A and the second side wall 201B are two side walls of the first recess 201 oppositely arranged in the length direction Z.

[0088] The first end protrusion 202A refers to the protrusion 202 closest to the first side wall 201A among the plurality of protrusions 202.

[0089] The second end protrusion 202B refers to the protrusion 202 closest to the second side wall 201B among the plurality of protrusions 202.

[0090] The second gap 102 between the first end protrusion 202A and the first side wall 201A in the length direction Z means that the side of the first end protrusion 202A facing the first side wall 201A in the length direction Z has the second gap 102 with the first side wall 201A.

[0091] The third gap 103 between the second end protrusion 202B and the second side wall 201B in the length direction Z means that the side of the second end protrusion 202B facing the second side wall 201B in the length direction Z has the third gap 103 with the second side wall 201B.

[0092] In the present embodiment, along the length direction Z, the first end protrusion 202A has the second gap 102 with the first side wall 201A, and the second end protrusion 202B has the third gap 103 with the second side wall 201B, so that the relative two sides of any protrusion 202 in the length direction Z are provided with the area for the second slurry to pass through, so that the second slurry flowing out of the first gap 101 has the second slurry not flowing out of the first gap 101 on both sides of the length direction Z of the die body 10, thereby reducing the time for the second slurry not flowing out of the first gap 101 to fill the second slurry flowing out of the first gap 101, and further improving the uniformity of the overall thickness of the second slurry, and improving the coating quality of the second slurry.

[0093] Please refer to Figure 4 According to some embodiments of the present application, the end surface of the gasket 20 in the width direction Y of the die body 10 has a second coating port 201C in communication with the first flow channel 10B; the convex portion 202 has a first end facing the second coating port 201C in the width direction Y, and the distance between the first end and the second coating port 201C in the width direction Y is H, which satisfies 0mm < H ≤ 2mm.

[0094] The first end is the end of the convex portion 202 that is closer to the second coating port 201C than the other end in the width direction Y.

[0095] H can take any one of the point values of 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, or a range value between any two of them.

[0096] In the present embodiment, when H > 0mm, a certain distance between the convex portion 202 and the second coating port 201C in the width direction Y can be provided to fill the second slurry flowing through the first gap 101 with the second slurry not flowing through the first gap 101, thereby improving the uniformity of the overall thickness of the second slurry and improving the coating quality of the second slurry; when H ≤ 2mm, the size of the first flow channel 10B in the width direction Y can be reduced, thereby reducing the size of the first groove 201 of the gasket 20 in the width direction Y, and further reducing the weakening of the strength of the gasket 20 by the first groove 201 and improving the strength of the gasket 20, thereby improving the reliability of the coating die 100; thereby, when 0mm < H ≤ 2mm, the uniformity of the overall thickness of the second slurry can be improved, the coating quality of the second slurry is improved, and the strength of the gasket 20 is improved, thereby improving the reliability of the coating die 100.

[0097] According to some embodiments of the present application, 0.5mm ≤ H ≤ 1mm.

[0098] H can take any one of the point values of 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or a range value between any two of them.

[0099] In the embodiment, when H>0.5mm, the convex part 202 and the second coating port 201C have a certain distance in the width direction Y, so that the second slurry flowing out through the first gap 101 is filled with the second slurry flowing out through the first gap 101, thereby further improving the uniformity of the overall thickness of the second slurry and improving the coating quality of the second slurry; when H≤1mm, the size of the first runner 10B in the width direction Y can be further reduced, thereby further reducing the size of the first groove 201 in the gasket 20 in the width direction Y, and further reducing the weakening of the strength of the gasket 20 by the first groove 201, thereby further improving the strength of the gasket 20 and improving the reliability of the coating die 100; thereby 0.5mm≤H≤1mm can further improve the uniformity of the overall thickness of the second slurry, improve the coating quality of the second slurry, and further improve the strength of the gasket 20, thereby improving the reliability of the coating die 100.

[0100] Please refer to Figure 6 , Figure 6 The coating die 100 provided by some embodiments of the application has another structure, which is a structure schematic diagram of the coating die 100 from the A perspective in Figure 2 According to some embodiments of the application, the first side is recessed to form a second groove 203 communicating with the first groove 201, and the second groove 203 and one of the first die 11 and the second die 12 form a second runner 10C for containing the second slurry.

[0101] The second groove 203 is a strip-shaped groove formed by recessing the first side, and the second groove 203 can be formed on the first side by machining methods such as turning and milling, or can be made synchronously with the first side by integral molding.

[0102] The second runner 10C is another structure of the coating die 100 for containing the second slurry.

[0103] The second groove 203 and one of the first die 11 and the second die 12 form a second runner 10C for containing the second slurry, which can be understood as that the second groove 203 and the side of the first die 11 facing the gasket 20 form the first runner 10B, or that the second groove 203 and the side of the second die 12 facing the gasket 20 form the first runner 10B. Please refer to Figure 6 , the ranges of the first runner 10B and the second runner 10C are identified by dashed lines in the figure, and it should be noted that the dashed lines only facilitate the display of the ranges of the first runner 10B and the second runner 10C, and do not represent any entity meaning.

[0104] If the first side is the side of the gasket 20 facing the first die body, the second recess 203 and the side of the first die head 11 facing the gasket 20 enclose the second flow channel 10C; if the first side is the side of the gasket 20 facing the second die body, the second recess 203 and the side of the second die head 12 facing the gasket 20 enclose the second flow channel 10C.

[0105] In some embodiments, one side of the gasket 20 in the width direction Y can be provided with a third coating opening 201D in communication with the second flow channel 10C, and the second slurry exits the second flow channel 10C through the third coating opening 201D and is coated on the substrate.

[0106] In some embodiments, the die head body 10 is provided with a discharge hole in communication with the second flow channel 10C, and the second slurry can exit the second flow channel 10C through the discharge hole and be collected.

[0107] In the present embodiment, the first recess 201 and the second recess 203 are in communication, and the second recess 203 and one of the first die head 11 and the second die head 12 enclose the second flow channel 10C for containing the second slurry, so that when the pressure in the first flow channel 10B increases due to the decrease in the flow of the second slurry, the second flow channel 10C can divert a portion of the second slurry, thereby reducing the risk of deformation of the gasket 20 due to the excessive pressure in the first flow channel 10B, and further reducing the risk of mixing of the second slurry in the first flow channel 10B and the first slurry in the containing cavity 10A due to the deformation of the gasket 20.

[0108] Please refer to Figure 7 , Figure 7 To Figure 6 is a sectional view of C-C. According to some embodiments of the present application, the size of the second flow channel 203 in the height direction X is equal to the size of the first flow channel 201 in the height direction X.

[0109] The size of the second recess 203 in the height direction X is equal to the size of the first recess 201 in the height direction X, which can be understood as the distance between the bottom wall of the first recess 201 and the first die body in the height direction X being equal to the distance between the bottom wall of the second recess 203 and the first die body in the height direction X, or the distance between the bottom wall of the first recess 201 and the second die body in the height direction X being equal to the distance between the bottom wall of the second recess 203 and the second die body in the height direction X.

[0110] In the embodiment, the size of the second groove 203 in the height direction X is equal to the size of the first groove 201 in the height direction X, on the one hand, so that the processing sizes of the second groove 203 and the first groove 201 are the same, facilitating the processing of the gasket 20; on the other hand, compared with the case that the depth of the second groove 203 is less than that of the first groove 201, the flow of the second slurry in the second flow channel 10C formed by the second groove 203 is increased, and the pressure relief capability of the second flow channel 10C to the first flow channel 10B is improved.

[0111] Please refer to Figure 6 According to some embodiments of the present application, the gasket 20 is recessed on one side in the width direction Y of the die body 10 to form a notch 204, the notch 204 and the side surfaces opposite to the first die 11 and the second die 12 form a first coating opening 10D in communication with the accommodating cavity 10A; the end surface of the gasket 20 in the width direction Y has a second coating opening 201C in communication with the first flow channel 10B and a third coating opening 201D in communication with the second flow channel 10C; along the length direction Z of the die body 10, the third coating opening 201D is located between the second coating opening 201C and the first coating opening 10D.

[0112] Exemplarily, the notch 204 can be made synchronously with the gasket 20 by using a processing method such as casting; the notch 204 can also be made by processing the whole blank of the gasket 20 by using a mechanical processing method such as milling. Please refer to Figure 6 In the figure, the range where the notch 204 is located is marked by a dashed line, and it should be noted that the dashed line only facilitates the display of the range of the notch 204 and does not represent any entity meaning.

[0113] It can be understood that the length of the first coating opening 10D in the length direction Z should be adapted to the width of the first slurry coated on the substrate, and the distance between the side of the second coating opening 201C away from the third coating opening 201D and the side of the third coating opening 201D away from the second coating opening 201C in the length direction Z should be adapted to the width of the second slurry coated on the substrate.

[0114] In some embodiments, the first groove 201 has a first side wall 201A close to the second groove 203 in the length direction Z, the first side wall 201A has a first guide surface for guiding the second slurry in the first flow channel 10B to move in the direction close to the third coating port 201D; the second groove 203 has a third side wall 201E close to the first groove 201 in the length direction Z, the third side wall 201E has a second guide surface for guiding the second slurry in the second flow channel 10C to move in the direction close to the second coating port 201C. In this way, the second slurry in the first flow channel 10B abuts against the second slurry in the second flow channel 10C in the length direction Z, so as to reduce the risk of the edge of the second slurry in the first flow channel 10B and the second slurry in the second flow channel 10C bulging due to the coffee ring effect when being coated on the substrate.

[0115] In the present embodiment, on the one hand, the end surface of the gasket 20 in the width direction Y has a third coating port 201D in communication with the second flow channel 10C, so that the second slurry in the second flow channel 10C can also be used for coating the pole piece, thereby reducing the waste of the second slurry and reducing the production cost; on the other hand, the third coating port 201D is located between the second coating port 201C and the first coating port 10D along the length direction Z of the die body 10, so that the second slurry coated on the substrate from the second coating port 201C is farther away from the first slurry than the second slurry coated on the substrate from the third coating port 201D, so that the second slurry coated on the substrate from the second coating port 201C is closer to the bending area, thereby reducing the thickness of the second slurry on the cathode pole piece close to the bending area, and thereby reducing the risk of the cathode tab cracking when being bent due to the excessive thickness of the second slurry on the cathode tab.

[0116] According to some embodiments of the present application, the gasket 20 has a first through hole for the second slurry to enter the first flow channel 10B, and one of the first die 11 and the second die 12 has a second through hole in communication with the first through hole.

[0117] The first through hole (not shown in the figure) is a through hole penetrating through the gasket 20 in the thickness direction of the gasket 20 to communicate with the first flow channel 10B and the second flow channel 10C. The first through hole (not shown in the figure) on the gasket 20 can be made by casting or other integrated processing methods synchronously with the gasket 20, so that the gasket 20 with the first through hole (not shown in the figure) can be manufactured synchronously as a whole, which not only makes the processing and manufacturing of the gasket 20 convenient, but also makes the overall structure of the gasket 20 have good strength; the first through hole (not shown in the figure) can also be made by milling or other mechanical processing methods by processing the whole blank of the gasket 20, so that the gasket 20 has lower processing difficulty and processing cost.

[0118] The second through hole (not shown in the figure) is provided on the first die 11 corresponding to the first through hole (not shown in the figure), one end of the second through hole (not shown in the figure) communicates with the first through hole (not shown in the figure), and the other end of the second through hole can communicate with the second slurry source through the connecting pipe.

[0119] In the embodiment, the gasket 20 has a first through hole for the second slurry to enter the flow channel, one of the first die 11 and the second die 12 has a second through hole communicating with the first through hole, thereby facilitating the injection of the second slurry into the first flow channel 10B through the second through hole, and facilitating the communication of the first flow channel 10B with the second slurry source.

[0120] The application also provides a coating device comprising the coating die 100.

[0121] According to some embodiments of the application, referring to Figures 1 to 7 The application provides a coating die 100 comprising a die body 10 and a gasket 20. The die body 10 comprises a first die 11 and a second die 12 stacked along the height direction X thereof, and the first die 11 and the second die 12 enclose a containing cavity 10A for containing a first slurry. The gasket 20 has a first side surface in the height direction X, and the first side surface is recessed to form a first recess 201, and the first recess 201 and one of the first die 11 and the second die 12 enclose a first flow channel 10B for containing a second slurry. The gasket 20 comprises a protruding portion 202 protruding from the bottom wall of the first recess 201 to block part of the first flow channel 10B.

[0122] The protruding portion 202 is a plurality of protruding portions 202 spaced apart along the length direction Z of the die body 10. Along the height direction X, the end surface of the protruding portion 202 away from the bottom wall has a first gap 101 with one of the first die 11 and the second die 12. The first recess 201 has oppositely arranged first and second side walls 201A and 201B in the length direction Z; one of the plurality of protruding portions 202 closest to the first side wall 201A is a first end protruding portion 202A, and the first end protruding portion 202A has a second gap 102 with the first side wall 201A in the length direction Z; one of the plurality of protruding portions 202 closest to the second side wall 201B is a second end protruding portion 202B, and the second end protruding portion 202B has a third gap 103 with the second side wall 201B in the length direction Z.

[0123] The end surface of the gasket 20 in the width direction Y of the die body 10 has a second coating opening 201C communicating with the first flow channel 10B. The protruding portion 202 has a first end facing the second coating opening 201C in the width direction Y, and the distance between the first end and the second coating opening 201C in the width direction Y is H, 0.5mm≤H≤1mm.

[0124] The first side is recessed to form a second recess 203 communicating with the first recess 201, and the second recess 203 is enclosed with one of the first die 11 and the second die 12 to form a second runner 10C for accommodating the second paste. The size of the second runner 203 in the height direction X is equal to that of the first runner 201 in the height direction X. The gasket 20 is recessed on one side in the width direction Y of the die body 10 to form a notch 204, and the notch 204 is enclosed with the opposite side of the first die 11 and the second die 12 to form a first coating port 10D communicating with the accommodating cavity 10A. The end surface of the gasket 20 in the width direction Y has a second coating port 201C communicating with the first runner 10B and a third coating port 201D communicating with the second runner 10C. In the length direction Z of the die body 10, the third coating port 201D is located between the second coating port 201C and the first coating port 10D. The gasket 20 has a first through hole for the second paste to enter the first runner 10B, and one of the first die 11 and the second die 12 has a second through hole communicating with the first through hole.

[0125] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0126] The above embodiments are only used to illustrate the technical solutions of the present application, and are not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A coating die characterized by, The coating die comprises: a die body comprising a first die and a second die stacked along a height direction of the die body, the first die and the second die enclosing a receiving cavity for receiving a first slurry; a gasket having a first side surface in the height direction, the first side surface being recessed to form a first groove, the first groove enclosing a first flow channel for receiving a second slurry with one of the first die and the second die; wherein the gasket comprises a plurality of protrusions protruding from a bottom wall of the first groove to block part of the first flow channel.

2. The coating die of claim 1, wherein The plurality of protrusions are spaced apart along a length direction of the die body.

3. The coating die of claim 2, wherein An end surface of the protrusion facing away from the bottom wall has a first gap with one of the first die and the second die along the height direction.

4. The coating die of claim 2, wherein The first groove has a first side wall and a second side wall oppositely arranged along the length direction; a first end protrusion closest to the first side wall among the plurality of protrusions has a second gap with the first side wall along the length direction; a second end protrusion closest to the second side wall among the plurality of protrusions has a third gap with the second side wall along the length direction.

5. The coating die of claim 1 wherein, An end surface of the gasket in a width direction of the die body has a second coating opening in communication with the first flow channel; the protrusion has a first end facing the second coating opening in the width direction, and a distance between the first end and the second coating opening in the width direction is H, satisfying 0mm < H ≤ 2mm.

6. The coating die of claim 5, wherein 0.5mm ≤ H ≤ 1mm.

7. The coating die of claim 1 wherein, The first side surface is recessed to form a second groove in communication with the first groove, the second groove enclosing a second flow channel for receiving a second slurry with one of the first die and the second die.

8. The coating die of claim 7, wherein A size of the second flow channel in the height direction is equal to a size of the first flow channel in the height direction.

9. The coating die of claim 7, wherein One side of the gasket in the width direction of the die body is recessed to form a notch, the notch enclosing a first coating opening in communication with the receiving cavity with opposite side surfaces of the first die and the second die; an end surface of the gasket in the width direction has a second coating opening in communication with the first flow channel and a third coating opening in communication with the second flow channel; along the length direction of the die body, the third coating opening is located between the second coating opening and the first coating opening.

10. The coating die of claim 1 wherein, The gasket has a first through hole for the second slurry to enter the first flow channel, and one of the first die and the second die has a second through hole in communication with the first through hole.

11. A coating apparatus characterized by comprising: The coating die comprises any one of claims 1-10. The coating die comprises any one of claims 1-10.

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