WO2023065104A1 - Thermal interface material coating method for battery cell - Google Patents

Abstract

Mainly disclosed is a thermal interface material coating method for a battery cell. The method comprises: performing a thermal interface material coating process on at least one battery cell by using a coating system comprising a rotating mechanism, a slit-type coating device, and a substrate; wherein the substrate is provided with a plurality of meshes. According to the design of the present invention, in the case that the fluid ejection flow rate of a slit nozzle of the slit-type coating device, the rotational speed of the rotating mechanism, the thickness of the substrate, and the mesh size of the substrate are properly controlled, the coating system can enable a layer of thermal interface material to be coated on the outer surface of the battery cell, and the transverse thickness of a film layer of the thermal interface material is uniform.

Description

Coating method of thermal interface material for battery cell technical field

The invention relates to the technical field of battery devices for electric vehicles, in particular to a thermal interface material coating method for battery cells.

Background technique

At present, the electric vehicle market is booming, and the battery is an important component related to the performance and cost of electric vehicles. Electric-vehicle battery (electric-vehicle battery), referred to as EVB, is used to supply electric motor energy of pure electric vehicle (BEV) or hybrid electric vehicle (HEV). To explain in more detail, the electric vehicle battery is also called a battery pack, which includes a plurality of battery cells and a battery management circuit module. FIG. 1 shows a perspective view of a conventional first battery cell, FIG. 2 shows a conventional perspective view of a second battery cell, and FIG. 3 shows a conventional perspective view of a third battery cell. As shown in Figure 1, Figure 2, and Figure 3, according to the different packaging methods, the three commonly used battery cells are: cylindrical battery cell (Cylindrical battery cell) B1a, square battery cell (Prismatic battery cell) ) B2a and pouch battery cell (Pouch battery cell) B3a.

For the convenience of assembly, the battery manufacturing factory will first form a plurality of battery cells into a battery module (Battery module), and then at least one battery module and the battery management circuit module into a battery pack. For example, Chinese Patent Publication No. CN111799405A discloses a battery module. Its technical feature is that when stacking and arranging a plurality of cylindrical battery cells, they adopt determinant arrangement and staggered arrangement, so as to improve space utilization and make multiple There is a large distance between the cylindrical battery cells, which helps to dissipate heat easily. In order to further improve the heat dissipation of each of the cylindrical battery cells, battery manufacturers usually soak each of the cylindrical battery cells in a high-K thermal interface material (Thermal Thermal Interface Material) before assembling the battery module. interface material (TIM) solution to form a thermal interface layer on the outer surface of each cylindrical battery cell. However, it is very difficult to control the uniformity of the lateral thickness of the film layer of the TIM material in the soaking method.

On the other hand, Chinese Patent Publication No. CN110915020A discloses a battery module, wherein the battery module includes a battery frame and a plurality of square battery cells arranged in the battery frame. Likewise, in order to further improve the heat dissipation of each of the cubic battery cells, a layer of thermal interface material may be coated on the outer surface of each of the cubic battery cells. Furthermore, Chinese Patent Publication No. CN111653707A discloses a battery module, wherein the battery module includes a plastic frame and a plurality of pouch battery cells arranged in the plastic frame. Similarly, in order to further improve the heat dissipation of each of the pouch battery cells, a layer of thermal interface material can be coated on the outer surface of each of the pouch battery cells. Generally speaking, a slot die coater can be used to coat the surface of a pouch battery cell or a square battery cell with TIM material.

Generally speaking, the internal channel design of the slit coater will affect the uniformity of the liquid outlet, thus directly affecting the uniformity of the transverse thickness of the final film layer. Therefore, after the conventional technology completes the slit coating process (slot die coating process) of the pouch battery cell or square battery cell, it will then be subjected to a spin process (Spin process) to ensure that the TIM material The uniformity of the lateral thickness of the film layer. However, such a method adds an additional step to the coating of the TIM material, and at the same time forces the slit coater to have a mechanism for rotating the substrate, resulting in an increase in the equipment cost of the slit coater.

It can be seen from the foregoing description that the conventional methods for coating thermal interface materials on the outer surfaces of cylindrical battery cells, cubic battery cells, and pouch battery cells obviously have room for improvement. In view of this, the inventor of this case made great efforts to research and invent, and finally developed a method for coating thermal interface materials of battery cells.

Contents of the invention

In view of the deficiencies described in the prior art, the main purpose of the present invention is to provide a thermal interface material coating method for battery cells, which utilizes a rotating mechanism, a slit coating device and a substrate The formed coating system performs a thermal interface material coating process on at least one battery cell; wherein, the substrate has a plurality of grids. According to the design of the present invention, under the condition of properly controlling the fluid ejection flow rate of the slit nozzle of the slit coating device, the rotational speed of the rotating mechanism, the thickness of the substrate, and the mesh size of the substrate , the coating system is capable of coating a layer of thermal interface material on the outer surface of the battery cell, and the lateral thickness of the film layer of the thermal interface material is uniform.

In order to achieve the above purpose, the present invention proposes a first embodiment of the thermal interface material coating method for battery cells, which includes the following steps:

(1) providing a rotating mechanism and a slot coating device, and filling a fluid made of a thermal interface material into a container portion of the slot coating device;

(2) fixing at least one single battery on the rotating mechanism so that the single battery is located below the slit coating device;

(3) placing a substrate having a plurality of mesh holes between the single battery and the slot coating device;

(4) In the case of driving the rotating mechanism to rotate the single battery, operate the slit coating device so that the fluid is coated on the substrate through a slit nozzle of the slit coating device on; and

(5) The fluid further flows through the plurality of mesh holes, and then is coated on the outer surface of the unit battery.

In one embodiment, when the rotating mechanism is driven to rotate the unit battery, the unit battery has a rotation speed that is negatively correlated with the viscosity of the fluid to be coated.

In one embodiment, the substrate is a curved substrate, and a radius of curvature thereof is between 3 mm and 50 mm.

In one embodiment, the thickness of the substrate is between 0.05 mm and 100 mm, and the mesh size of the mesh is between 10 and 200 mesh.

In a possible embodiment, the substrate is coated with a layer of smooth material, so that the fluid does not stick to the substrate and the mesh.

In one embodiment, the single battery is a cylindrical battery cell, and the thermal interface material includes a polymer matrix and a plurality of thermal conductive elements distributed in the polymer matrix. filler.

In a feasible embodiment, a scraper (Squeegee) is provided at the edge of the slit nozzle, so that when the step (2) is performed, the fluid 2 is ejected from the slit nozzle, and then brushed by the squeegee. coated on the substrate.

In a feasible embodiment, the slit coating device further includes a pressurizing part communicated with the container part, and a pressurizing plate is arranged in the pressurizing part; wherein, a pressurizing force providing device provides a pressurizing When pressure is applied to the pressure plate, the pressure plate moves downward at a moving speed, thereby pushing the fluid in the container portion. Moreover, the pressure providing device is a pneumatic pressure machine or a mechanical pressure machine.

In a possible embodiment, a heating device is connected to the outer surface of the container part for heating the fluid in the container part.

Moreover, the present invention also proposes a second embodiment of the thermal interface material coating method for battery cells, which includes the following steps:

(1) providing a moving mechanism and a slot coating device, and filling a fluid made of a thermal interface material into a container portion of the slot coating device;

(2) fixing at least one single battery on the moving mechanism so that the single battery is located below the slit coating device;

(3) placing a substrate having a plurality of mesh holes between the single battery and the slot coating device;

(4) When the moving mechanism is driven to drive the single battery to move in a horizontal direction, the slit coating device is operated so that the fluid is coated through a slit nozzle of the slit coating device overlies the substrate; and

(5) The fluid further flows through the plurality of mesh holes, and then is coated on the outer surface of the unit battery.

In one embodiment, when the moving mechanism is driven to drive the single battery to move along the horizontal direction, the single battery has a moving speed ranging from 1 cm/s to 30 cm/s.

In one embodiment, the thickness of the substrate is between 0.05 mm and 100 mm, and the mesh size of the mesh is between 10-200 mesh.

In a possible embodiment, the substrate is coated with a layer of smooth material, so that the fluid does not stick to the substrate and the mesh.

In one embodiment, the unit battery is a square battery unit (Prismatic battery cell) or a pouch battery unit (Pouch battery cell), and the thermal interface material includes a polymer matrix (Polymer matrix) and distributed A plurality of thermally conductive fillers in the polymer matrix.

In a feasible embodiment, a scraper (Squeegee) is provided at the edge of the slit nozzle, so that when the step (2) is performed, the fluid 2 is ejected from the slit nozzle, and then brushed by the squeegee. coated on the substrate.

In a feasible embodiment, the slit coating device further includes a pressurizing part communicated with the container part, and a pressurizing plate is arranged in the pressurizing part; wherein, a pressurizing force providing device provides a pressurizing When pressure is applied to the pressure plate, the pressure plate moves downward at a moving speed, thereby pushing the fluid in the container portion. Moreover, the pressure providing device is a pneumatic pressure machine or a mechanical pressure machine.

In a possible embodiment, a heating device is connected to the outer surface of the container part for heating the fluid in the container part. .

The detailed features and advantages of the present invention are described in detail in the following embodiments, the content of which is sufficient to enable those skilled in the art to understand the technical content of the present invention and implement it accordingly, and according to the content disclosed in the description of the present invention, the scope of the patent application and the drawings , the related objects and advantages of the present invention can be easily understood.

Description of drawings

FIG. 1 is a perspective view of a conventional first battery cell;

FIG. 2 is a perspective view of a second conventional battery cell;

Fig. 3 is a perspective view of a third conventional battery cell;

4 is a first perspective view of a thermal interface material coating system for a battery cell of the present invention;

5 is a second perspective view of the thermal interface material coating system for battery cells of the present invention;

6 is an exploded perspective view of the thermal interface material coating system for battery cells of the present invention;

7 is a first side sectional view of a thermal interface material coating system for a battery cell according to the present invention;

Fig. 8 is a first flowchart of a thermal interface material coating method for a battery cell according to the present invention;

9 is a second side sectional view of the thermal interface material coating system for battery cells of the present invention;

FIG. 10 is a second flow chart of a thermal interface material coating method for a battery cell according to the present invention.

illustration:

<this invention>

1: Thermal interface material coating system for battery cells

11: Turning mechanism

11a: Mobile Mechanism

12: Slot coating device

121: Container Department

122: Slit nozzle

123: Scraper

124: pressurized part

12P: Pressure plate

13: Substrate

14: Pressure supply device

15: Heating device

B1: battery cell

B2: battery cell

S1-S5: Method steps

S1a-S5a: Method steps

<knowledge>

B1a: Cylindrical battery cell

B2a: Cube battery cell

B3a: Soft pack battery cell

Detailed ways

The foregoing and other technical contents, features and effects of the present invention will be clearly presented below in conjunction with the drawings and the detailed description of the preferred embodiments. The directional terms mentioned in the embodiments, such as: up, down, left, right, front or back, etc., are only used for reference orientation, so the directional terms used are for the purpose of illustration, not to limit the scope of the present invention. invention.

In order to more clearly describe a thermal interface material coating method for battery cells proposed by the present invention, preferred embodiments of the present invention will be described in detail below with reference to the drawings.

first embodiment

The invention proposes a method for coating a thermal interface material of a battery cell. In the first embodiment, a rotating mechanism, a slot die coater and a curved substrate are used to implement the thermal interface material coating method for a battery cell. In other words, it can also be said that the rotating mechanism, the slit coating device and the curved base form a thermal interface material coating system for battery cells.

FIG. 4 shows a first perspective view of a thermal interface material coating system for a battery cell of the present invention, and FIG. 5 shows a second perspective view of the thermal interface material coating system for a battery cell of the present invention. Moreover, FIG. 6 shows a three-dimensional exploded view of the thermal interface material coating system for battery cells of the present invention. Further, FIG. 7 shows a first side sectional view of the thermal interface material coating system for battery cells of the present invention. Furthermore, Fig. 8 shows a first flow chart of a thermal interface material coating method for battery cells according to the present invention.

As shown in Fig. 4 to Fig. 7 and Fig. 8, the process of the method firstly executes step S1: provide a rotating mechanism 11 and a slit coating device 12, and fill in a fluid 2 made of a thermal interface material to In a container portion 121 of the slit coating device 12 . Further, the method flow is to execute step S2: fixing at least one unit battery B1 on the rotating mechanism 11 so that the unit battery B1 is located below the slit coating device 12 . Subsequently, the method flow is to execute step S3: placing a substrate 13 with a plurality of mesh holes between the single battery B1 and the slot coating device 12 . It is worth noting that a scraper (Squeegee) 123 is provided at the mouth edge of the slit nozzle 122, so that when the step (2) is performed, the fluid 2 is ejected from the slit nozzle 122, and then the fluid 2 is sprayed by the scraper. A plate 123 is painted on the substrate 13 .

As shown in FIG. 4 to FIG. 7 , the substrate 13 is a curved substrate, and a radius of curvature thereof is between 3 mm and 50 mm. It should be understood that since the single battery B1 is a cylindrical battery cell, the radius of curvature is adjusted according to the diameter (ie, Φ value) of the single battery B1. On the other hand, the thickness of the substrate 13 is between 0.05 mm and 100 mm, and the mesh size of the mesh is between 10 and 200 mesh. The mesh number mentioned here refers to the number of meshes in the area (1 inch x 1 inch). Of course, the wire diameter and hole diameter can be adjusted according to the mesh number.

As shown in FIG. 4 to FIG. 7 and FIG. 8, the method flow proceeds to step S4: in the case of driving the rotating mechanism 11 to rotate the unit battery B1, operate the slit coating device 12 to allow the fluid 2 to pass through A slit nozzle 122 of the slit coating device 12 is coated on the substrate 13 . It is worth noting that, when the rotating mechanism 11 is driven to rotate the unit battery B1, the unit battery B1 has a rotation speed that is negatively correlated with the viscosity of the fluid to be coated, that is, The rotation speed of the single battery B1 can be adjusted according to the viscosity of the thermal interface material to be coated. If the viscosity is higher, the rotation speed should be adjusted to be slower. The faster it turns. Assume that if the rotational angular velocity of the rotating mechanism 11 is ω, the radius of the battery cell B1 is R, and if the tangential speed of the battery cell rotation is the same as the moving speed V2 of the moving mechanism 11a, that is, ω*R=V2, then the relationship can be obtained Formula to adjust the rotational angular velocity ω of the single battery.

In such a design, in the subsequent step S5, the fluid 2 will further flow through the plurality of mesh holes, and then be coated on the outer surface of the single battery B1. It is added that, in a feasible embodiment, the substrate 13 can be coated with a smooth material layer, so that the fluid 2 does not stick to the substrate 13 and the meshes thereof, and the smooth material described herein The material layer is preferably a composite material composed of polymer materials and inorganic material particles, wherein the polymer materials are selected from: polymethyl methacrylate, polyamide, polystyrene, polyethylene, polypropylene, One of polyimide, polyurethane, polypyrrole, polylactic acid, fluorocarbon resin, epoxy resin, etc., any combination thereof or derivatives thereof. The inorganic material particles are selected from: graphite nano particles, boron nitride particles, carbon black, activated carbon, fullerene, graphene, etc., any combination thereof or derivatives thereof. In this composite material, the weight percent range of polymers in the smooth material layer is 1-68wt%, and the weight percent range of inorganic material particles in the smooth material layer is 5-40wt%.

It should be understood that when properly controlling the flow rate of the fluid 2 ejected from the slit nozzle 122, the rotation speed of the single battery B1, the thickness of the substrate 13, the mesh size of the substrate 13, and the curvature of the substrate 13 In the case of a radius, the thermal interface material coating system 1 for battery cells shown in Figures 4 to 7 can coat a layer of thermal interface material on the outer surface of the cylindrical battery cell B1, and the The lateral thickness of the film layer of the thermal interface material is uniform. Moreover, after the surface coating of the thermal interface material of the plurality of battery cells B1 is completed, the plurality of battery cells B1 can be further assembled into a battery module (Battery module), and then at least one battery module is combined with A battery management circuit module is assembled together into a battery pack.

In particular, what is disclosed in the present invention is a thermal interface material coating method and system for battery cells, so the technical feature of the present invention does not lie in the composition of the thermal interface material used to make the fluid 2 . Generally speaking, as disclosed in Chinese Patent Publication No. CN101351755A, the thermal interface material includes a polymer matrix and a plurality of thermally conductive fillers distributed in the polymer matrix. Wherein, the thermally conductive filler may be metal oxide particles, nitride particles, carbide particles, diboride particles, graphite particles, metal particles and the like. Of course, the thermal interface material can be adjusted flexibly according to the needs, such as adding metal oxide ceramic fillers, such as alumina, magnesium oxide, zinc oxide, zirconia, etc., or adding nitride ceramic fillers such as: aluminum nitride, boron nitride, Silicon nitride, etc., or add carbon-based fillers such as graphite, graphene, etc., and add carbide fillers such as: silicon carbide, tungsten carbide, carbon nanotubes, graphite, carbon black, etc.

As shown in Figures 4 to 7, in a feasible embodiment, the slit coating device 12 further includes a pressurizing part 124 communicating with the container part 121, and a pressurizing plate 12P is arranged on the pressurizing part 124. part 124; wherein, when a pressurizing force providing device 14 provides a pressurizing force to the pressurizing plate 12P, the pressurizing plate 12P moves downward according to a moving speed, thereby pushing the fluid in the container part 121 2. The pressure providing device 14 can be a pneumatic pressure machine or a mechanical pressure machine. For example, FIG. 7 shows that the pressure providing device 14 is a pneumatic pressure machine.

As shown in Figures 4 to 7, in a feasible embodiment, the thermal interface material coating system 1 for battery cells of the present invention further includes: a heating device 15, which is connected to the outer surface of the container part 121 The surface is used for heating the fluid 2 in the container part 121 .

second embodiment

In the second embodiment, a translation mechanism, a slot die coater and a flat substrate are used to implement the thermal interface material coating method for battery cells. In other words, it can also be said that the moving mechanism, the slit coating device and the planar substrate form a thermal interface material coating system for battery cells.

FIG. 9 shows a second side cross-sectional view of the thermal interface material coating system for battery cells of the present invention. Furthermore, FIG. 10 shows a second flowchart of a thermal interface material coating method for a battery cell according to the present invention.

As shown in Figures 9 and 10, the method flow is to firstly execute step S1a: provide a moving mechanism 11a and a slit coating device 12, and fill a fluid 2 made of a thermal interface material into the slit In a container part 121 of the formula coating device 12. Further, the method flow is to execute step S2a: fixing at least one single battery B2 on the moving mechanism 11a, so that the single battery B2 is located below the slit coating device 12 . Next, the method flow is to execute step S3a: placing a substrate 13 with a plurality of mesh holes between the unit battery B2 and the slot coating device 12 . It is worth noting that a scraper (Squeegee) 123 is provided at the mouth edge of the slit nozzle 122, so that when the step (2) is performed, the fluid 2 is ejected from the slit nozzle 122, and then the fluid 2 is sprayed by the scraper. A plate 123 is painted on the substrate 13 .

As shown in FIGS. 9 and 10 , the substrate 13 is a planar substrate. On the other hand, the thickness of the substrate 13 is between 0.05 mm and 100 mm, and the mesh size of the mesh is between 10 and 200 mesh.

As shown in Figures 9 and 10, the method flow proceeds to step S4a: when the moving mechanism 11a is driven to drive the single battery B2 to move in a horizontal direction, the slit coating device 12 is operated to make the fluid 2 is coated on the substrate 13 through a slot nozzle 122 of the slot coating device 12. It is worth noting that, when the moving mechanism 11a is driven to drive the single battery B2 to move along the horizontal direction, the single battery B2 has a moving speed ranging from 1 cm/s to 30 cm/s . To further illustrate, the moving speed V2 of the moving mechanism 11a can be based on the coating amount Q of the thermal interface material per unit time, the cross-sectional area A of the slit nozzle 122, the coating speed V1 of the thermal interface material, and the coating thickness of the single battery B2 t, the coating width W of the single battery B2 and other factors are adjusted, that is, Q=A*V1=V2*t*W, and according to A, V1, t, W, the moving speed of the moving mechanism 11a can be adjusted V2. In such a design, in the subsequent step S5a, the fluid 2 will further flow through the plurality of mesh holes, and then be coated on the outer surface of the single battery B2. It is added that, in a feasible embodiment, the substrate 13 may be coated with a smooth material layer, so that the fluid 2 does not stick to the substrate 13 and the mesh.

It should be understood that under the conditions of properly controlling the flow rate of the fluid 2 ejected from the slit nozzle 122, the moving speed of the single battery B2, the thickness of the substrate 13, and the mesh size of the substrate 13, as The thermal interface material coating system 1 for a battery cell shown in FIG. 9 is capable of coating a layer of thermal interface material on the outer surface of the battery cell B2, and the film layer of the thermal interface material has a uniform lateral thickness. sex. In a feasible embodiment, the battery cell B2 is a square battery cell (Prismatic battery cell) or a pouch battery cell (Pouch battery cell). Moreover, after the surface coating of the thermal interface material of the plurality of battery cells B2 is completed, the plurality of battery cells B2 can be further assembled into a battery module (Battery module), and then at least one battery module and A battery management circuit module is assembled together into a battery pack.

In particular, what is disclosed in the present invention is a thermal interface material coating method and system for battery cells, so the technical feature of the present invention does not lie in the composition of the thermal interface material used to make the fluid 2 . Generally speaking, as disclosed in Chinese Patent Publication No. CN101351755A, the thermal interface material includes a polymer matrix and a plurality of thermally conductive fillers distributed in the polymer matrix. Wherein, the thermally conductive filler may be oxide particles, nitride particles, carbide particles, diboride particles, graphite particles, metal particles and the like.

As shown in FIG. 9, in the second implementation, the slit coating device 12 may further include a pressurizing part 124 communicated with the container part 121, and a pressurizing plate 12P is arranged on the pressurizing part 124 Wherein, when a pressurizing force providing device 14 provides a pressurizing force to the pressurizing plate 12P, the pressurizing plate 12P moves downward according to a moving speed, thereby pushing the fluid 2 of the container part 121 . The pressure providing device 14 can be a pneumatic pressure machine or a mechanical pressure machine. For example, FIG. 9 shows that the pressure providing device 14 is a pneumatic pressure machine.

As shown in FIG. 9, in the second implementation, the thermal interface material coating system 1 for battery cells of the present invention may also further include: a heating device 15, which is connected to the outer surface of the container portion 121, It is used for heating the fluid 2 in the container part 121 .

Thus, the above is a complete and clear description of a thermal interface material coating method for battery cells of the present invention. It must be emphasized that the above detailed description is a specific description of the feasible embodiment of the present invention, but the embodiment is not used to limit the patent scope of the present invention, and any equivalent implementation or modification without departing from the technical spirit of the present invention , should be included in the patent scope of this case.

In addition, the specific implementation forms disclosed in the present invention include a plurality of features that are commonly described and can cooperate with each other to provide a series of benefits; moreover, any reference to the requested element is referred to in the singular, such as "a", "here ", or "described", and should not be considered as limiting this element to a singular number; that is, all equivalent changes and modifications made according to the patent scope of the present invention are covered by the patent scope of the present invention.

Claims (20)

A method for coating a thermal interface material for a battery cell, comprising the following steps: (1) providing a rotating mechanism and a slot coating device, and filling a fluid made of a thermal interface material into a container portion of the slot coating device; (2) fixing at least one single battery on the rotating mechanism so that the single battery is located below the slit coating device; (3) placing a substrate having a plurality of mesh holes between the single battery and the slot coating device; (4) In the case of driving the rotating mechanism to rotate the single battery, operate the slit coating device so that the fluid is coated on the substrate through a slit nozzle of the slit coating device on; and (5) The fluid further flows through the plurality of mesh holes, and then is coated on the outer surface of the unit battery. The thermal interface material coating method for a battery cell according to claim 1, wherein, when the rotating mechanism is driven to rotate the single battery, the single battery has a rotation speed that is equal to the desired The viscosity of the applied fluid showed a negative correlation. The thermal interface material coating method for a battery cell as claimed in claim 1, wherein the substrate is a curved substrate, and a radius of curvature thereof is between 3 mm and 50 mm. The coating method of thermal interface material for a battery cell as claimed in claim 1, wherein the substrate is coated with a smooth material layer so that the fluid does not stick to the substrate and the mesh. The thermal interface material coating method for battery cells as claimed in claim 1, wherein the thickness of the substrate is between 0.05 mm and 100 mm, and the mesh size of the mesh is between 10 and 200 mesh between. The thermal interface material coating method for a battery cell as claimed in claim 1, wherein the single battery is a cylindrical battery cell (Cylindrical battery cell), and the thermal interface material comprises a polymer matrix ( Polymer matrix) and a plurality of thermally conductive fillers distributed in the polymer matrix. The thermal interface material coating method for battery cells according to claim 1, wherein a scraper (Squeegee) is provided at the edge of the slit nozzle, so that when the step (2) is performed, the fluid Sprayed by the slit nozzle, and then brushed on the substrate by the squeegee. The thermal interface material coating method for a battery cell according to claim 1, wherein the slit coating device further comprises a pressurizing part communicated with the container part, and a pressurizing plate is arranged on the In the pressurizing part; wherein, under the condition that a pressurizing force providing device provides a pressurizing force to the pressurizing plate, the pressurizing plate moves downward according to a moving speed, thereby pushing the fluid in the container part. The method for coating a thermal interface material for a battery cell according to claim 1, wherein the pressure providing device is a pneumatic pressure machine or a mechanical pressure machine. The method of coating a thermal interface material for a battery cell as claimed in claim 1, wherein a heating device is connected to the outer surface of the container portion for heating the fluid in the container portion. A method for coating a thermal interface material for a battery cell, comprising the following steps: (1) providing a moving mechanism and a slot coating device, and filling a fluid made of a thermal interface material into a container portion of the slot coating device; (2) fixing at least one single battery on the moving mechanism so that the single battery is located below the slit coating device; (3) placing a substrate having a plurality of mesh holes between the single battery and the slot coating device; (4) When the moving mechanism is driven to drive the single battery to move in a horizontal direction, the slit coating device is operated so that the fluid is coated through a slit nozzle of the slit coating device overlies the substrate; and (5) The fluid further flows through the plurality of mesh holes, and then is coated on the outer surface of the unit battery B1. The thermal interface material coating method for battery cells as claimed in claim 11, wherein when the moving mechanism is driven to drive the single cells to move along the horizontal direction, the single cells have a range of A moving speed between 1 cm/s and 30 cm/s. The thermal interface material coating method for battery cells as claimed in claim 11, wherein, the substrate is coated with a smooth material layer, so that the fluid does not stick to the substrate and the mesh. The thermal interface material coating method for a battery cell as claimed in claim 11, wherein the cell is a Prismatic battery cell or a Pouch battery cell, And the thermal interface material includes a polymer matrix (Polymer matrix) and a plurality of thermal conductive fillers distributed in the polymer matrix. The thermal interface material coating method for battery cells as claimed in claim 11, wherein the thickness of the substrate is between 0.05 mm and 100 mm, and the mesh size of the mesh is between 10-200 mesh between. The thermal interface material coating method for a battery cell as claimed in claim 11, wherein a scraper (Squeegee) is provided at the edge of the slit nozzle. The thermal interface material coating method for battery cells as claimed in claim 16, wherein, when performing the step (2), the fluid is sprayed from the slit nozzle, and then brushed on the substrate by the scraper above. The thermal interface material coating method for battery cells as claimed in claim 11, wherein the slit coating device further comprises a pressurizing part communicated with the container part, and a pressurizing plate is arranged on the In the pressurizing part; wherein, under the condition that a pressurizing force providing device provides a pressurizing force to the pressurizing plate, the pressurizing plate moves downward according to a moving speed, thereby pushing the fluid in the container part. The method for coating a thermal interface material for a battery cell as claimed in claim 11 , wherein the pressure providing device is a pneumatic pressure machine or a mechanical pressure machine. The method for coating a thermal interface material for a battery cell as claimed in claim 11, wherein a heating device is connected to the outer surface of the container portion for heating the fluid in the container portion.

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