CN220611068U - Coating device and battery production system - Google Patents

Abstract

The application discloses coating device and battery production system. The coating device comprises: the extrusion die head assembly, the inside of extrusion die head assembly is formed with the reservoir, and the one end of extrusion die head assembly is formed with the feed inlet that link up mutually with the reservoir, and the other end of extrusion die head assembly is formed with the discharge gate that link up with the reservoir, and the size of discharge gate, feed inlet and reservoir three along the first direction is the same, and the first direction is the same with the length direction of discharge gate. The size of discharge gate, feed inlet and reservoir three along the first direction is the same, in the feeding in-process, can reduce the thick liquids volume of following first direction diffusion to reduce the pressure loss of thick liquids in the runner, thereby can make the homogeneity of the velocity of flow of different positions of discharge gate better, in order to improve the thickness homogeneity of the coating at the mass flow body surface.

Description

Coating device and battery production system

Technical Field

The present application relates to battery manufacturing equipment, and in particular, to a coating apparatus and a battery production system.

Background

In the process of manufacturing the pole piece, slurry needs to be coated on the surface of a current collector to form the pole piece, in the coating process, the current collector is discharged through a discharge hole of an extrusion die head assembly, and moves relative to the extrusion die head assembly, so that the slurry of the discharge hole is continuously coated on the surface of a substrate, and the problem is that the uniformity of the thickness of a coating layer on the surface of the current collector in the coating process is poor.

Disclosure of Invention

In view of the above, the application provides a coating device and a battery production system, through the improvement to discharge gate, feed inlet and reservoir, can improve the thick liquids velocity of flow of different positions of discharge gate to improve the thickness homogeneity of the coating on electric current collector surface.

In a first aspect, the present application provides a coating apparatus comprising:

the extrusion die head assembly, the inside of extrusion die head assembly is formed with the reservoir, and the one end of extrusion die head assembly is formed with the feed inlet that link up with the reservoir, and the other end of extrusion die head assembly is formed with the discharge gate that link up with the reservoir, and the size of discharge gate, feed inlet and reservoir along the first direction is the same, and the first direction is the same with the length direction of discharge gate.

When the size of the feed inlet along the first direction is smaller than that of the discharge outlet along the first direction, slurry entering from the feed inlet can diffuse in a liquid storage tank of the extrusion die head assembly along the first direction, flow resistance can be generated in the flow diffusion process to generate pressure loss, so that the flow velocity distribution of the slurry at different positions of the discharge outlet of the extrusion die head assembly is uneven, the uniformity of the thickness of a coating layer coated on a current collector is poor in the coating process, and the performance of a battery is affected. The size of the discharge hole, the size of the feed hole and the size of the liquid storage tank along the first direction are the same, and in the feeding process, the size of the slurry diffused along the first direction can be reduced, so that the pressure loss of the slurry in the flow channel can be reduced, the uniformity of the flow velocity at different positions of the discharge hole can be improved, and the thickness uniformity of the coating layer coated on the surface of the current collector can be improved.

In some embodiments, the coating device further comprises a gear pump provided with a delivery port connected to the feed port, the delivery port being for feeding the feed port. The gear pump is used for pumping the slurry, the rotating speed range of the gear pump is large, the pumping performance is good under the slurry with high viscosity, the gear pump is suitable for the slurry with the viscosity larger than 300cP, the conveying requirement of the battery slurry can be met, the instantaneous flow of the gear pump is relatively stable, the pulse is not easy to generate, the flow in the coating process can be well controlled, and the thickness uniformity of the coating layer on the surface of the current collector in the coating process can be better.

In some embodiments, the transfer port has a dimension W1 in the first direction and the feed port has a dimension W2 in the first direction, wherein 0.9.ltoreq.W1/W2.ltoreq.1.1. When W1/W2 is smaller than 0.9 or W1/W2 is larger than 1.1, the size of the conveying port along the first direction is too small or large, when the conveying port conveys slurry to the feeding port, a part of slurry flows to two ends of the feeding port, the slurry has different flow rates at different positions of the discharging port due to different speeds of the slurry at different positions of the feeding port due to conveying resistance, and the thickness uniformity of a coating layer on the surface of the current collector is affected. Therefore, W1/W2 is more than or equal to 0.9 and less than or equal to 1.1, the slurry flowing from the conveying port to the two ends of the feeding port can be reduced, the difference of flow velocity of the slurry at different positions of the discharging port is further reduced, and the thickness uniformity of the coating layer on the surface of the current collector in the coating process is better.

In some embodiments, 0.95.ltoreq.W1/W2.ltoreq.1.05. Therefore, the difference of flow velocity of the slurry at different positions of the discharge port can be further reduced, and the uniformity of the thickness of the coating layer on the surface of the current collector in the coating process can be better.

In some embodiments, the width direction of the gears in the gear pump is the same as the first direction, and the tooth width of the gears in the gear pump is W3, wherein W3/W1 is more than or equal to 0.9 and less than or equal to 1. The tooth width of the gear pump is set to be generally consistent with the width of the conveying port, the uniformity of the flow velocity of slurry pumped to the conveying port through the gear is good, and the difference of the flow velocity of slurry pumped from the conveying port to the feeding port and from the feeding port to the discharging port can be reduced, so that the uniformity of the thickness of a coating layer on the surface of a current collector in the coating process is improved.

In some embodiments, 0.95.ltoreq.W3/W1.ltoreq.1. Therefore, the difference of the flow rates of the slurry pumped from the conveying port to the feeding port and the slurry pumped from the feeding port to the discharging port can be further reduced, so that the thickness uniformity of the coating layer on the surface of the current collector in the coating process is improved.

In some embodiments, W3 ranges from 400mm to 2500mm. Therefore, the requirements of the coating devices with different specifications for conveying the sizing agent can be met.

In some embodiments, the gear pump comprises an external gear pump. The gear pump adopts an internal gear pump, so that flow pulsation can be rapidly increased under the working condition of high viscosity and high rotating speed, and meanwhile, the volumetric efficiency is rapidly reduced; the external gear pump has simple structure, low price and convenient maintenance. Therefore, the gear pump is an external gear pump.

In some embodiments, the external gear pump comprises a variable displacement pump. Thus, the thickness of the coating layer coated on the current collector can be changed by changing the flow rate of the gear pump.

In some embodiments, the coating device further comprises a controller electrically connected to the gear pump, the controller for controlling the rotational speed of the gear pump. The gear pump is more convenient compared with the manual rotation speed adjusting gear pump through the rotation speed control of the controller.

In some embodiments, the extrusion die assembly includes a first die having a reservoir formed therein and a feed port formed at one end of the first die in communication with the reservoir. The liquid storage tank and the feed inlet are arranged on the first die head, so that the liquid storage tank and the feed inlet can be conveniently communicated, and the structure is simplified.

In some embodiments, the extrusion die assembly further comprises a second die and a gasket, the second die and the first die are arranged at intervals along a second direction, the second direction is perpendicular to the first direction, the gasket is arranged between the first die and the second die, a gap communicated with the liquid storage tank is formed at one end of the gasket, which is away from the feed inlet, and at least part of the gap forms the discharge outlet. From this, feed inlet, reservoir, breach and discharge gate form the passageway that carries the thick liquids, can make the thick liquids that send out through the delivery port of gear pump pass through feed inlet, reservoir, breach and discharge gate coating at the surface of mass flow body, the feed inlet the discharge gate with the size of reservoir three along the first direction is the same, can make the homogeneity of the velocity of flow of different positions of discharge gate better.

In a second aspect, the present application provides a battery production system comprising the coating device of the first aspect for applying a slurry to a current collector.

Since the battery production system includes all the technical features of the coating device of the second aspect, the effects are the same as those described above, and are not described in detail herein.

The foregoing description is only an overview of the technical solutions of the present application, and may be implemented according to the content of the specification in order to make the technical means of the present application more clearly understood, and in order to make the above-mentioned and other objects, features and advantages of the present application more clearly understood, the following detailed description of the present application will be given.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the application. Also, like reference numerals are used to designate like parts throughout the accompanying drawings. In the drawings:

FIG. 1 is a side view of a coating apparatus according to some embodiments of the present application;

FIG. 2 is an isometric view of an extrusion die assembly of a coating apparatus according to some embodiments of the present application;

FIG. 3 is a front view of FIG. 2;

FIG. 4 is a top view of a shim coupled to a first die in an extrusion die assembly according to a first embodiment of the present application;

FIG. 5 is a top view of a shim coupled to a first die in an extrusion die assembly according to a second embodiment of the present application;

FIG. 6 is an isometric view of a gear pump in a coating apparatus according to some embodiments of the present application;

fig. 7 is an isometric view of a gear within a gear pump in a coating device according to some embodiments of the present application.

Reference numerals in the specific embodiments are as follows:

10. an extrusion die assembly; 11. a first die; 111. a feed inlet; 112. a liquid storage tank; 12. a second die; 13. a gasket; 131. a discharge port; 20. a gear pump; 21. a gear; 22. a delivery port; 30. a controller; A. a first direction; B. a second direction.

Detailed Description

Embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical solutions of the present application, and thus are only examples, and are not intended to limit the scope of protection of the present application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first," "second," etc. are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the present application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, which means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two), and similarly, "plural sets" refers to two or more (including two), and "plural sheets" refers to two or more (including two).

In the description of the embodiments of the present application, the orientation or positional relationship indicated by the technical terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. are based on the orientation or positional relationship shown in the drawings, and are merely for convenience of describing the embodiments of the present application and for simplifying the description, rather than indicating or implying that the apparatus or element referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of the present application.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured" and the like are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.

In the process of manufacturing the pole piece, slurry needs to be coated on the surface of a current collector to form the pole piece, in the coating process, the current collector is discharged through a discharge hole of an extrusion die head assembly, and moves relative to the extrusion die head assembly, so that the slurry of the discharge hole is continuously coated on the surface of a substrate, and the problem is that the uniformity of the thickness of a coating layer on the surface of the current collector in the coating process is poor. Specifically, the pressure of the slurry at different positions of the discharge port of the coating device is different, so that the uniformity of the flow velocity of the slurry at different positions of the discharge port is poor, the uniformity of the thickness of the coating layer coated on the surface of the current collector is poor, and the performance of the battery is affected.

In view of this, the present application provides a coating apparatus that can improve uniformity of flow rates of slurry at different positions of a discharge port by improving the sizes of an extrusion die assembly, a liquid reservoir, and the discharge port. Specifically, the sizes of the feed inlet, the discharge outlet and the liquid storage tank along the first direction are the same, in the feeding process, the slurry quantity diffused along the first direction can be reduced, so that the pressure loss of the slurry in the flow channel is reduced, the pressure difference of the slurry at different positions in the flow channel is smaller, according to the Bernoulli equation, the pressure at the same position is smaller, the flow speed is correspondingly larger, the pressure is larger, the flow speed is smaller, the pressure loss is smaller, the flow speed difference is also reduced, and the slurry flowing out from different positions of the discharge outlet is more uniform, so that the thickness uniformity of a coating layer coated on the surface of a current collector is improved.

The coating device provided by the application can be applied to manufacturing of adhesive tapes, film negative films, functional diaphragms, packaging films and wallpaper, and can also be used in high-value-added electronic industry: such as printed circuit board, capacitor film, optical film, surface hardening coating, photoresist coating of display substrate, etc.; the method can also be applied to the rapidly-developed renewable energy industry: such as copper indium gallium selenide thin film solar cells, high molecular solar cells, lithium batteries and the like, such as coating of battery pole pieces.

For convenience of description, please refer to fig. 1-7, which illustrate a coating apparatus according to some embodiments of the present application.

The coating apparatus includes an extrusion die assembly 10. Wherein, the inside of extrusion die head subassembly 10 is formed with reservoir 112, and extrusion die head subassembly 10's one end is formed with the feed inlet 111 that link up mutually with reservoir 112, and extrusion die head subassembly 10's the other end is formed with the discharge gate 131 that link up with reservoir 112, and the size of discharge gate 131, feed inlet 111 and reservoir 112 along first direction A is the same, and first direction A is the same with the length direction of discharge gate 131.

Alternatively, the number of discharge ports 131 of the extrusion die assembly 10 may be set to one or more. When the number of the discharge ports 131 is plural, the plural discharge ports 131 are arranged at intervals in the first direction a, and the extrusion die assembly 10 may form a plurality of coating areas on the current collector when coating the current collector.

When the number of the discharge ports 131 is plural, the dimension of the discharge port 131 in the first direction a refers to the distance between the outermost two discharge ports 131 in the first direction a, and the dimension of the discharge port 131 in the first direction a is Lmax in fig. 5; when the number of the discharge ports 131 is one, the size of the discharge ports 131 in the first direction a is L-size in fig. 4. The size of the reservoir 112 in the first direction a is the L1 size in fig. 4. The size of the feed opening 111 in the first direction a is the W2 size in fig. 3.

When the size of the feed inlet 111 along the first direction a is smaller than the size of the discharge outlet 131 along the first direction a, the slurry entering from the feed inlet 111 diffuses in the liquid storage tank 112 of the extrusion die assembly 10 along the first direction a, and flow resistance and pressure loss are generated in the process of flow diffusion, so that the flow velocity distribution of the slurry at different positions of the discharge outlet 131 of the extrusion die assembly 10 is uneven, and the uniformity of the thickness of the coating layer coated on the current collector is poor in the coating process, thereby affecting the performance of the battery. The dimensions of the discharge port 131, the feed port 111 and the liquid storage tank 112 along the first direction a are the same, in the feeding process, the amount of slurry diffusing along the first direction a can be reduced, so as to reduce the pressure loss of the slurry in the flow channel, according to the bernoulli equation, the pressure at the same position is reduced, the flow rate is correspondingly increased, the pressure is increased, the flow rate is reduced, the pressure loss is reduced, the difference of the flow rates is reduced, and the uniformity of the flow rates at different positions of the discharge port 131 is improved, so that the thickness uniformity of the coating layer coated on the surface of the current collector is improved.

In some embodiments, referring to fig. 1, the coating apparatus further includes a gear pump 20, where the gear pump 20 is provided with a delivery port 22, and the delivery port 22 is connected to the feed port 111, and the delivery port 22 is used for feeding the feed port 111.

The delivery port 22 of the gear pump 20 refers to a connection port for discharging the pump of the gear pump 20.

The gear pump 20 is used for pumping slurry, the rotating speed range of the gear pump 20 is large, the pumping performance is good under high-viscosity slurry, the gear pump is suitable for slurry with the viscosity of more than 300cP, the conveying requirement of battery slurry can be met, the instantaneous flow of the gear pump 20 is relatively stable, pulse generation is not easy, the flow in the coating process can be well controlled, and the thickness uniformity of a coating layer on the surface of a current collector in the coating process can be better.

In some embodiments, referring to fig. 3 and 6, the dimension of the delivery port 22 along the first direction a is W1, and the dimension of the feed port 111 along the first direction a is W2, wherein 0.9+.w1/w2+.1.1.

When W1/W2 is less than 0.9 or W1/W2 is more than 1.1, the size of the conveying port 22 is too small or large, when the conveying port 22 conveys slurry to the feeding port 111, a part of slurry flows to two ends of the feeding port 111, the slurry at different positions of the feeding port 111 has different flow rates due to different speeds of the slurry at different positions of the discharging port 131 due to conveying resistance, and the thickness uniformity of a coating layer on the surface of the current collector is affected. Therefore, W1/W2 is more than or equal to 0.9 and less than or equal to 1.1, the slurry flowing from the conveying port 22 to the two ends of the feeding port 111 can be reduced, and the difference of flow velocity of the slurry at different positions of the discharging port 131 can be further reduced, so that the thickness uniformity of the coating layer on the surface of the current collector in the coating process can be better.

In some embodiments, please refer to fig. 3 and 6,0.95, W1/W2 is 1.05.

Therefore, the difference of flow velocity of the slurry at different positions of the discharge hole 131 can be further reduced, so that the uniformity of the thickness of the coating layer on the surface of the current collector in the coating process can be better.

In some embodiments, referring to fig. 6 and 7, the width direction of the gear 21 in the gear pump 20 is the same as the first direction a, and the tooth width of the gear 21 in the gear pump 20 is W3, wherein 0.9+.w3/w1+.1. The tooth width of the gear 21 of the gear pump 20 is set to be substantially consistent with the width of the delivery port 22, so that the uniformity of the flow rate of the slurry delivered to the delivery port 22 by the gear pump 20 is good, and the difference of the flow rates of the slurry pumped from the delivery port 22 to the feed port 111 and from the feed port 111 to the discharge port 131 can be reduced, so as to improve the uniformity of the thickness of the coating layer on the surface of the current collector in the coating process.

In some embodiments, please refer to fig. 6 and 7,0.95, W3/W1 is 1. Thus, the difference in flow rate of the slurry pumped from the delivery port 22 to the feed port 111 and from the feed port 111 to the discharge port 131 can be further reduced to improve the uniformity of the thickness of the coating layer on the surface of the current collector during the coating process.

In some embodiments, referring to FIG. 7, W3 has a value in the range of 400mm-2500mm.

Therefore, the requirements of the coating devices with different specifications for conveying the sizing agent can be met.

In some embodiments, the gear pump 20 comprises an external gear pump 20.

The external gear pump 20 is a pump in which gears 21 in the gear pump 20 are engaged with two external gears 21.

The gear pump 20 adopts an internal gear pump 20, so that flow pulsation can be rapidly increased under the working condition of high viscosity and high rotating speed, and simultaneously, the volumetric efficiency is rapidly reduced; and the external gear pump 20 has simple structure, low price and convenient maintenance. Therefore, the gear pump 20 is an external gear pump 20.

In some embodiments, the external gear pump 20 comprises a variable displacement pump.

Thus, the thickness of the coating layer coated on the current collector may be changed by changing the flow rate of the gear pump 20.

In some embodiments, referring to fig. 1, the coating apparatus further includes a controller 30 electrically connected to the gear pump 20, and the controller 30 is used for controlling the rotation speed of the gear pump 20.

Alternatively, the controller 30 may be communicatively connected to a display terminal through which data is input, and the rotational speed of the gear pump 20 is adjusted by the controller 30.

Alternatively, a flow sensor may be disposed at an input port of the gear pump 20, where the flow sensor is communicatively connected to the controller 30, and the controller 30 may adjust the flow rate of the gear pump 20 according to the flow data collected by the flow sensor.

Optionally, the controller 30 includes, but is not limited to, a single chip or a PLC programmable controller, etc.

The gear pump 20 controls the rotation speed through the controller 30, and compared with manual adjustment of the rotation speed of the gear pump 20, the rotation speed control method is more convenient.

In some embodiments, referring to fig. 2, the extrusion die assembly 10 includes a first die 11, a liquid storage tank 112 is formed inside the first die 11, and a feed inlet 111 communicating with the liquid storage tank 112 is formed at one end of the first die 11.

Alternatively, the depth direction of the feed port 111 may be perpendicular to the first direction a.

Alternatively, the feed inlet 111 may have an equal area in different cross sections perpendicular to the depth direction of the feed inlet 111.

The liquid storage tank 112 and the feeding port 111 are arranged on the first die head 11, so that the liquid storage tank and the feeding port are convenient to communicate, and the structure is simplified.

In some embodiments, referring to fig. 2, the extrusion die assembly 10 further includes a second die 12 and a gasket 13, the second die 12 and the first die 11 are disposed at intervals along a second direction B, the second direction B is perpendicular to the first direction a, the gasket 13 is disposed between the first die 11 and the second die 12, a gap communicating with the liquid storage tank 112 is formed at one end of the gasket 13 facing away from the feed inlet 111, and at least a part of the gap forms the discharge outlet 131.

Alternatively, the number of the notches may be one or more. When the number of the notches is plural, the notches are arranged at intervals along the first direction a, that is, a plurality of discharge ports 131 are formed at intervals at one end of the first die 11 facing away from the feed port 111.

Optionally, the first die head 11 is connected with the second die head 12 through bolts, the gasket 13 is tightly pressed and sealed, and partial gaps are blocked by the first matching surface and the second matching surface to form partial flow channels for conveying the slurry.

Therefore, the feeding port 111, the liquid storage tank 112, the notch and the discharging port 131 form a channel for conveying slurry, the slurry sent out through the conveying port 22 of the gear pump 20 can be coated on the surface of the current collector through the feeding port 111, the liquid storage tank 112, the notch and the discharging port 131, the sizes of the feeding port 111, the discharging port 131 and the liquid storage tank 112 along the first direction are the same, and the uniformity of flow rates at different positions of the discharging port 131 can be better.

For convenience of explanation, the following examples will take a battery production system of some embodiments of the present application as an example.

The battery production system includes the coating device of the above embodiment for coating the slurry to the current collector.

Alternatively, the current collector includes, but is not limited to, copper foil or aluminum foil, and the like.

Since the battery production system includes all technical features of the coating device of the above embodiment, the effects are the same as those described above, and will not be described in detail here.

In an alternative embodiment, referring to FIGS. 1-7, a coating apparatus includes an extrusion die assembly 10, an external gear pump 20, and a controller 30. Wherein the external gear pump 20 is a variable displacement pump. The inside of the extrusion die head assembly 10 is formed with a liquid storage tank 112, one end of the extrusion die head assembly 10 is formed with a feed inlet 111 communicated with the liquid storage tank 112, the other end of the extrusion die head assembly 10 is formed with a discharge outlet 131 communicated with the liquid storage tank 112, the dimensions of the discharge outlet 131, the feed inlet 111 and the liquid storage tank 112 along a first direction A are the same, and the first direction A is the same as the length direction of the discharge outlet 131. The externally engaged gear pump 20 is a variable pump, the gear pump 20 is provided with a delivery port 22, the delivery port 22 is connected with the feed port 111, and the delivery port 22 is used for feeding the feed port 111. The controller 30 is electrically connected with the gear pump 20, and the controller 30 is used for controlling the flow rate of the gear pump 20. The size of the conveying opening 22 along the first direction A is W1, the size of the feeding opening 111 along the first direction A is W2, the width direction of the gear 21 in the gear pump 20 is the same as the first direction A, the tooth width of the gear 21 in the gear pump 20 is W3, wherein W1/W2 is more than or equal to 0.9 and less than or equal to 1.1, W3/W1 is more than or equal to 0.9 and less than or equal to 1, and the value range of W3 is 400mm-2500mm.

0.9.ltoreq.W1/W2.ltoreq.1.1, 0.9.ltoreq.W3/W1.ltoreq.1, the extrusion die assembly 10 conveys the slurry through the externally engaged gear pump 20, the tooth width of the gear pump 20 can be made substantially the same as the dimension of the flow channel for conveying the slurry in the extrusion die assembly 10 along the first direction A, so as to reduce the flow of the slurry along the first direction A, thereby reducing the pressure loss of the slurry in the conveying process, reducing the difference of the flow velocity of the slurry at different positions of the discharge hole 131, and improving the uniformity of the thickness of the coating layer coated on the current collector. The gear pump 20 is a variable pump, and the flow rate of the gear pump 20 can be adjusted so that the thickness of the coating layer coated on the current collector can be changed as required. In addition, the gear pump 20 is used for pumping the slurry, the rotating speed range of the gear pump 20 is large, the pumping performance is good under the slurry with high viscosity, the gear pump is suitable for the slurry with the viscosity larger than 300cP, the conveying requirement of the battery slurry can be met, the instantaneous flow of the gear pump 20 is relatively stable, the pulse is not easy to generate, the flow in the coating process can be well controlled, and the thickness uniformity of the coating layer on the surface of the current collector in the coating process can be better.

Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the embodiments, and are intended to be included within the scope of the claims and description. In particular, the technical features mentioned in the respective embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions falling within the scope of the claims.

Claims (13)

1. A coating apparatus, characterized by comprising:

the extrusion die head assembly, the inside of extrusion die head assembly is formed with the reservoir, the one end of extrusion die head assembly be formed with the feed inlet that the reservoir link up, the other end of extrusion die head assembly be formed with the discharge gate that the reservoir link up, the discharge gate the feed inlet with the size of reservoir along the first direction is the same, the first direction with the length direction of discharge gate is the same.

2. The coating device according to claim 1, further comprising a gear pump provided with a delivery port connected to the feed port, the delivery port being for feeding the feed port.

3. The coating apparatus of claim 2, wherein the dimension of the delivery port in the first direction is W1 and the dimension of the feed port in the first direction is W2, wherein 0.9 ∈w1/w2 ∈1.1.

4. A coating apparatus according to claim 3, wherein 0.95.ltoreq.w1/w2.ltoreq.1.05.

5. The coating apparatus according to claim 3 or 4, wherein a width direction of a gear in the gear pump is the same as the first direction, and a tooth width of the gear is W3, wherein 0.9.ltoreq.w3/w1.ltoreq.1.

6. The coating apparatus of claim 5, wherein 0.95.ltoreq.W3/W1.ltoreq.1.

7. The coating apparatus according to any one of claims 2 to 4, wherein the tooth width of the gear in the gear pump is W3, and the value of W3 is in the range of 400mm to 2500mm.

8. The coating apparatus of any one of claims 2-4, wherein the gear pump comprises an external gear pump.

9. The coating apparatus of claim 8 wherein the external gear pump comprises a variable displacement pump.

10. The coating device of any one of claims 2-4, further comprising a controller electrically connected to the gear pump, the controller configured to control a rotational speed of the gear pump.

11. The coating apparatus according to any one of claims 1 to 4, wherein the extrusion die assembly comprises a first die having the reservoir formed therein and having the feed port formed at one end thereof so as to communicate with the reservoir.

12. The coating apparatus of claim 11, wherein the extrusion die assembly further comprises a second die and a gasket, the second die and the first die are disposed at intervals along a second direction, the second direction is perpendicular to the first direction, the gasket is disposed between the first die and the second die, a gap is formed at one end of the gasket facing away from the feed inlet, the gap is in communication with the liquid reservoir, and at least a portion of the gap forms the discharge outlet.

13. A battery production system comprising the coating device according to any one of claims 1 to 12 for applying a slurry to a current collector.