A coating system for lithium battery electrode sheets

Abstract

The utility model provides a kind of coating system of lithium battery pole piece, comprising: coating mechanism, for coating substrate, along the movement direction of substrate, it is equipped successively: back roll, support on substrate;Coating die head, for active slurry is coated to the surface of substrate to form active slurry area, with discharge end, discharge end is towards the outer circumferential surface of back roll, and there is the gap that can pass substrate between discharge end and the outer circumferential surface of back roll;First drying device, for pre-drying to reduce the flowability of active slurry to active slurry area;Dispensing device, for ceramic slurry is coated in the both sides of active slurry area;Second drying device, for the substrate of completing coating is dried.Using the above technical scheme, the problem of mixing and virtual edge can be effectively solved.

Description

Technical Field

[0001] This utility model belongs to the field of lithium battery technology, specifically relating to a coating system for lithium battery electrodes. Background Technology

[0002] Coating technology involves using specialized equipment to uniformly coat one or more layers of a coating with specific properties onto a carrier surface, followed by drying and other subsequent processing to ultimately create a material with the desired performance. In traditional lithium-ion battery coating processes, active slurry and ceramic slurry are typically coated together on the current collector surface and then dried, with the ceramic slurry generally coated on both sides of the active slurry. However, due to the difference in solid content between the active and ceramic slurries, surface tension causes the ceramic slurry to migrate towards the active slurry area during the baking and drying process. This results in quality problems such as mutual dissolution and loose edges at the interface between the two slurry areas on the dried electrode. Utility Model Content

[0003] The present invention provides the following technical solutions to solve the above-mentioned technical problems.

[0004] This utility model provides a coating system for lithium battery electrodes, comprising:

[0005] A coating mechanism, used for coating a substrate, is provided sequentially along the direction of movement of the substrate as follows:

[0006] Back roller, supporting the substrate;

[0007] A coating die head is used to coat an active slurry onto the surface of the substrate to form an active slurry area. It has a discharge end facing the outer peripheral surface of the back roller, and there is a gap between the discharge end and the outer peripheral surface of the back roller that allows the substrate to pass through.

[0008] The first drying device is used to pre-dry the active slurry zone to reduce the fluidity of the active slurry;

[0009] A dispensing device for coating ceramic slurry onto both sides of the active slurry area;

[0010] The second drying device is used to dry the coated substrate.

[0011] The above technical solution effectively solves the problems of material mixing and false edges. Specifically, after the active slurry is applied to the substrate, it is first pre-dried by a first drying device to reduce its fluidity. After the fluidity of the active slurry is reduced, a ceramic slurry is applied to both sides of the active slurry area by a dispensing device. Finally, a second drying device dries both slurries on the substrate as a whole. The pre-drying treatment effectively prevents the active slurry from adsorbing the ceramic slurry due to its excessive fluidity, and also significantly reduces the risk of ceramic slurry migrating to the active slurry area. In addition, the subsequent overall drying further ensures that the two slurries solidify and form in a stable state, greatly reducing the possibility of mixing and thus largely avoiding the problems of mixing and false edges at the interface of the material areas.

[0012] According to another specific embodiment of the present invention, the coating mechanism further includes:

[0013] An exhaust fan is connected to the first drying device. The active slurry contains a solvent, and the exhaust fan is used to discharge the solvent evaporated by the heated active slurry.

[0014] According to another specific embodiment of the present invention, the coating mechanism further includes:

[0015] A spraying device is located between the first drying device and the second drying device along the direction of movement of the substrate, and has a nozzle facing the active slurry area, the nozzle being used to spray solvent onto the active slurry area to prevent it from drying out.

[0016] According to another specific embodiment of the present invention, the dispensing device is an external dispensing device.

[0017] According to another specific embodiment of the present invention, the external dispensing device includes:

[0018] The sliding guide rail extends along the first direction;

[0019] The retractable dispensing head is slidably mounted on the guide rail and can move along the first direction, and can also extend and retract along the height direction of the external dispensing device, wherein the first direction, the movement direction of the substrate, and the height direction are perpendicular to each other.

[0020] According to another specific embodiment of the present invention, the first drying device and the second drying device are provided with air supply pipes for conveying hot air, and the air supply pipes are provided with air nozzles, which face the substrate and are used to convey the hot air to the substrate.

[0021] According to another specific embodiment of the present invention, there are multiple air nozzles, which are arranged along a first direction. The distance between two adjacent air nozzles along the first direction is 30-50cm. The first direction, the movement direction of the substrate, and the height direction of the first drying device are perpendicular to each other.

[0022] According to another specific embodiment of the present invention, the nozzle is also arranged along the movement direction of the substrate.

[0023] According to another specific embodiment of the present invention, there are two coating mechanisms, namely a first coating mechanism and a second coating mechanism. The second coating mechanism is located downstream of the first coating mechanism along the movement direction of the substrate. The first coating mechanism is used to coat one side of the substrate, and the second coating mechanism is used to coat the other side of the substrate.

[0024] According to another specific embodiment of the present invention, the first drying device, the dispensing device and the second drying device in the second coating mechanism are located above the first coating mechanism along the height direction of the lithium battery coating system. Attached Figure Description

[0025] Figure 1 A schematic diagram of a coating mechanism in one embodiment of the present invention is shown;

[0026] Figure 2 A schematic diagram of the coating mechanism in another embodiment of the present invention is shown. Detailed Implementation

[0027] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. Although the description of this utility model will be presented in conjunction with preferred embodiments, this does not mean that the features of this utility model are limited to this embodiment. On the contrary, the purpose of describing the utility model in conjunction with the embodiments is to cover other options or modifications that may be derived based on the claims of this utility model. To provide a deep understanding of this utility model, many specific details will be included in the following description. This utility model may also be implemented without using these details. Furthermore, to avoid confusion or obscuring the focus of this utility model, some specific details will be omitted in the description. It should be noted that, without conflict, the embodiments and features in the embodiments of this utility model can be combined with each other.

[0028] The terms “first”, “second”, etc., are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0029] It should be noted that in this specification, similar reference numerals and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0030] To make the objectives, technical solutions, and advantages of this utility model clearer, the embodiments of this utility model will be described in further detail below with reference to the accompanying drawings.

[0031] like Figure 1 As shown, this utility model provides a coating system for lithium battery electrodes, comprising:

[0032] The coating mechanism 100 is used to coat the substrate 3 along the direction of movement of the substrate 3. Figure 1 In the A direction, the following are sequentially set:

[0033] Back roller 2, supported on substrate 3, rotates clockwise (e.g., ...). Figure 1 (As shown in A1);

[0034] The coating die head 1 is used to coat the active slurry onto the surface of the substrate 3 to form an active slurry area. It has a discharge end 1.1 facing the outer peripheral surface of the back roller 2. There is a gap between the discharge end 1.1 and the outer peripheral surface of the back roller 2 that allows the substrate 3 to pass through.

[0035] The first drying device 4 is used to pre-dry the active slurry zone to reduce the fluidity of the active slurry;

[0036] Dispensing device 5 is used to coat ceramic slurry on both sides of the active slurry area;

[0037] The second drying device 6 is used to dry the coated substrate 3.

[0038] Compared to traditional coating mechanisms, the coating mechanism provided by this invention effectively solves the problems of material mixing and false edges. Specifically, after the active slurry is applied to the substrate 3, it is first pre-dried by a first drying device 4 to reduce its fluidity. After the fluidity of the active slurry is reduced, a ceramic slurry is applied to both sides of the active slurry area by a dispensing device 5. Finally, a second drying device 6 dries both slurries on the substrate as a whole. The pre-drying treatment effectively prevents the active slurry from adsorbing the ceramic slurry due to its excessive fluidity, and also significantly reduces the risk of the ceramic slurry migrating to the active slurry area. In addition, the subsequent overall drying further ensures that the two slurries solidify and form in a stable state, greatly reducing the possibility of mixing between the two, thereby greatly avoiding the problems of mixing and false edges at the interface of the material areas.

[0039] Furthermore, in the above embodiment, the coating mechanism also includes an exhaust fan (not shown in the figure), which is connected to the first drying device 4. Since the active slurry typically contains solvents, these solvents will evaporate during the pre-drying process. The function of the exhaust fan is to promptly remove these evaporated solvents. This ensures that the evaporated solvents do not accumulate in the first drying device 4, thereby ensuring the pre-drying effect and, consequently, the stable operation of subsequent processes.

[0040] Furthermore, in the above embodiments, the coating mechanism 1 further includes:

[0041] The spraying device (not shown in the figure) is located between the first drying device 4 and the second drying device 6 along the movement direction A2 of the substrate 3. It has a nozzle facing the active slurry area. The nozzle is used to spray solvent onto the active slurry area to prevent it from drying out.

[0042] The purpose of pre-drying is to reduce the fluidity of the active slurry to avoid mixing problems. However, if the substrate is over-dried after pre-drying, it is prone to cracking defects. This cracking will further lead to the active material in the cracked area falling off during the charge-discharge cycle of the battery cell as the active material expands and contracts, ultimately causing battery cell failure. To address this, the present invention provides a spraying device between the first drying device 4 and the second drying device 6. By spraying solvent onto the substrate that has reached a certain degree of dryness, it can effectively prevent over-drying and thus avoid the above-mentioned problems.

[0043] Furthermore, in the above embodiments, the dispensing device 5 is an external dispensing device. When coating ceramic slurry, the external dispensing device can adapt to different material zone widths and the requirements of tab clearance processes.

[0044] Furthermore, in the above embodiments, the external dispensing device includes:

[0045] Sliding guide rail (not shown in the figure), along the first direction (e.g.) Figure 1 (C) Extend in the direction of the middle;

[0046] A retractable dispensing head (not shown in the figure) is slidably mounted on a guide rail and can move along a first direction C, and can also move along the height direction of the external dispensing device (e.g., along the height direction of the external dispensing device). Figure 1 In the direction B), the extension and contraction occur, where the first direction C, the substrate's movement direction A, and the height direction B are perpendicular to each other. Specifically, the substrate's movement direction A is... Figures 1-2 A2 and A5 in the text.

[0047] With the above structure, the external dispensing device can flexibly adapt to and precisely control the coating position of ceramic slurry by adjusting the position of the dispensing head in the first direction C and the extension and retraction in the height direction B according to actual production needs, effectively improving the equipment's adaptability to different process conditions.

[0048] Furthermore, such as Figure 2 As shown in the embodiments above, the first drying device 4 and the second drying device 6 are equipped with air supply ducts 13 for conveying hot air. The air supply ducts 13 are equipped with nozzles 14, which face the substrate 3 and are used to deliver hot air to the substrate 3. Specifically, the hot air can be heated by electric heating, steam heating, or heat transfer oil heating. This design enables rapid drying of the substrate 3, thereby ensuring the effectiveness of pre-drying and final drying.

[0049] Furthermore, in the above embodiments, there are multiple air nozzles 14, which are arranged along the first direction C, and the distance between two adjacent air nozzles 14 along the first direction C is 30-50cm. The first direction C, the movement direction A of the substrate 3, and the height direction B of the first drying device 4 are perpendicular to each other.

[0050] This setup ensures that hot air evenly covers the surface of substrate 3, thereby avoiding the problem of uneven drying in certain areas.

[0051] Furthermore, such as Figure 2 As shown in the embodiments above, the nozzles 14 are also arranged along the movement direction A of the substrate 3. This ensures that the substrate 3 is always within the hot air coverage area during the conveying process, ensuring that the drying effect of each area of ​​the substrate 3 is consistent, thereby achieving continuous and uniform pre-drying and final drying effects.

[0052] Furthermore, in the above embodiments, such as Figures 1-2 As shown, there are two coating mechanisms 100, namely a first coating mechanism 100.1 and a second coating mechanism 100.2. The second coating mechanism 100.2 is located downstream of the first coating mechanism 100.1 along the movement direction A of the substrate 3. The first coating mechanism 100.1 is used to coat one side of the substrate, and the second coating mechanism 100.2 is used to coat the other side of the substrate 3. In this embodiment, the substrate 3, after being dried by the second drying device 6, is conveyed to the back roller 8 of the second coating mechanism 100.2 via the guide roller 7. The rotation direction of the guide roller 7 in the second coating mechanism 100.2 is as follows... Figures 1-2 As shown in direction A3, the rotation direction of the back roller 8 is as follows: Figures 1-2 As shown in direction A4, the coating die 9 of the second coating mechanism 100.2 coats the active slurry onto the other side of the substrate 3 to form an active slurry area. Subsequently, the substrate 3 passes through the first drying device 10, the dispensing device 11 and the second drying device 12 in sequence along the movement direction A5, finally completing the double-sided coating process of the substrate 3.

[0053] Furthermore, in the above embodiments, such as Figures 1-2As shown, the first drying device 10, the dispensing device 11, and the second drying device 12 in the second coating mechanism 100.2 are located above the first coating mechanism 100.1 along the height direction of the lithium battery coating system. This stacked spatial layout design effectively reduces the horizontal area occupied by the coating mechanism. Compared with the traditional horizontal parallel layout, by extending the second coating mechanism 100.2 vertically, the space utilization rate is significantly improved, thereby achieving the goal of saving factory floor space.

[0054] Although the present invention has been illustrated and described with reference to certain preferred embodiments, those skilled in the art should understand that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions. Those skilled in the art can make various changes in form and detail, including some simple deductions or substitutions, without departing from the spirit and scope of the present invention.

Claims

1. A coating system for lithium battery electrodes, characterized in that, include: A coating mechanism, used for coating a substrate, is provided sequentially along the direction of movement of the substrate as follows: Back roller, supporting the substrate; A coating die head is used to coat an active slurry onto the surface of the substrate to form an active slurry area. It has a discharge end facing the outer peripheral surface of the back roller, and there is a gap between the discharge end and the outer peripheral surface of the back roller that allows the substrate to pass through. The first drying device is used to pre-dry the active slurry zone to reduce the fluidity of the active slurry; A dispensing device for coating ceramic slurry onto both sides of the active slurry area; The second drying device is used to dry the coated substrate.

2. The coating system for lithium battery electrodes according to claim 1, characterized in that, The coating mechanism further includes: An exhaust fan is connected to the first drying device. The active slurry contains a solvent, and the exhaust fan is used to discharge the solvent evaporated by the heated active slurry.

3. The coating system for lithium battery electrodes according to claim 1, characterized in that, The coating mechanism further includes: A spraying device is located between the first drying device and the second drying device along the direction of movement of the substrate, and has a nozzle facing the active slurry area, the nozzle being used to spray solvent onto the active slurry area to prevent it from drying out.

4. The coating system for lithium battery electrodes according to claim 1, characterized in that, The dispensing device is an external dispensing device.

5. The coating system for lithium battery electrodes according to claim 4, characterized in that, The external dispensing device includes: The sliding guide rail extends along the first direction; The retractable dispensing head is slidably mounted on the guide rail and can move along the first direction, and can also extend and retract along the height direction of the external dispensing device, wherein the first direction, the movement direction of the substrate, and the height direction are perpendicular to each other.

6. The coating system for lithium battery electrodes according to claim 1, characterized in that, The first drying device and the second drying device are provided with air supply pipes for conveying hot air. The air supply pipes are provided with air nozzles, which face the substrate and are used to convey the hot air to the substrate.

7. The coating system for lithium battery electrodes according to claim 6, characterized in that, The air nozzles are multiple, and the multiple air nozzles are arranged along a first direction. The distance between two adjacent air nozzles along the first direction is 30-50cm. The first direction, the movement direction of the substrate, and the height direction of the first drying device are perpendicular to each other.

8. The coating system for lithium battery electrodes according to claim 6, characterized in that, The nozzles are also arranged along the direction of movement of the substrate.

9. The coating system for lithium battery electrodes according to claim 1, characterized in that, There are two coating mechanisms, namely a first coating mechanism and a second coating mechanism. The second coating mechanism is located downstream of the first coating mechanism along the movement direction of the substrate. The first coating mechanism is used to coat one side of the substrate, and the second coating mechanism is used to coat the other side of the substrate.

10. The coating system for lithium battery electrodes according to claim 9, characterized in that, The first drying device, the dispensing device, and the second drying device in the second coating mechanism are located above the first coating mechanism along the height direction of the lithium battery coating system.

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