Pole piece coating system

Abstract

The utility model discloses a pole piece coating system which comprises an unwinding mechanism used for unwinding foil, a coating mechanism used for coating at least one surface of the foil with slurry, a drying mechanism used for baking to remove a solvent, a moisture detection mechanism used for detecting the moisture content of a coating and a winding mechanism used for winding a pole piece. The unwinding mechanism, the coating mechanism, the drying mechanism, the moisture detection mechanism and the winding mechanism are sequentially arranged in the tape conveying direction of the foil. After at least one surface of the foil is coated with slurry through the coating mechanism and is baked by the drying mechanism to remove a solvent to form a coating, the moisture detection mechanism can directly detect the moisture content of the coating. Therefore, the water content of the coating can be accurately and rapidly detected on the premise that the structure of the pole piece is not damaged, the waste of the pole piece can be reduced, the detection cost can be reduced, and the method is an important means for ensuring the quality of the pole piece, improving the production efficiency, reducing the production cost and enhancing the production flexibility.

Description

Technical Field

[0001] This application relates to the field of battery production equipment technology, and in particular to an electrode coating system. Background Technology

[0002] In the production process of lithium-ion battery electrodes, a coating device first applies a slurry to a substrate. After coating, the electrode is conveyed to a drying oven for drying. After drying, the electrode is wound up and then transferred to a rolling device for pressing. The detection of the electrode's water content is crucial in the production process because it directly affects the electrode's performance, the battery's cycle life, and its safety. Excessive water content can lead to internal short circuits and capacity decay. Therefore, efficient and accurate detection of electrode water content is essential for improving battery quality.

[0003] The water content of the electrode is only a few hundred ppm, which is relatively low. The Karl Fischer coulometric method, an electrochemical detection method, is generally used for detection. The electrode sample is placed in a sealed sample bottle, heated at a certain temperature to evaporate the water. The water vapor is then carried into an electrolytic cell using a dry gas to participate in the reaction. The amount of electricity required for electrolysis is measured, and the water content is determined by titration. However, titration, as an extraction method, requires significant time and effort and has poor accuracy. This detection method cannot detect in real time and requires damage to the electrode, making it unsuitable for widespread application. Furthermore, this method requires strict control of drying temperature, heating time, sample volume, and sampling environment, making it difficult to guarantee the accuracy of the detected structure. Utility Model Content

[0004] To address the aforementioned deficiencies in the prior art, the purpose of this application is to provide an electrode coating system for timely and accurate detection of water content during electrode coating.

[0005] This application provides an electrode coating system, comprising: an unwinding mechanism for unwinding foil, a coating mechanism for coating at least one surface of the foil with a slurry, a drying mechanism for baking to remove solvent, a moisture detection mechanism for detecting the water content of the coating, and a winding mechanism for winding up the electrode. The unwinding mechanism, coating mechanism, drying mechanism, moisture detection mechanism, and winding mechanism are arranged sequentially along the conveyor belt direction of the foil.

[0006] In a preferred embodiment, the unwinding mechanism in this application includes an unwinding roller and an unwinding tension roller, which are arranged sequentially along the foil's travel direction.

[0007] In a preferred embodiment, the coating mechanism in this application includes a coating die, a traction coating roller, and a pressure roller. The coating die is positioned corresponding to the traction coating roller to coat the slurry onto at least one surface of the foil, and the traction coating roller and the pressure roller are positioned corresponding to the pressing sides of the foil.

[0008] In a preferred embodiment, the drying mechanism in this application includes an oven and a solvent concentration detection device. Coated foil passes through the oven to bake and remove the solvent, and the solvent concentration detection device is located at the outlet of the oven.

[0009] In a preferred embodiment, the moisture detection mechanism in this application includes a near-infrared luminometer, a near-infrared sensor, and an analysis and processing system. The near-infrared luminometer is configured to emit near-infrared light corresponding to the coating of the foil. The near-infrared sensor is located on the transmission path of the near-infrared light reflected by the coating. The near-infrared sensor is electrically connected to the analysis and processing system.

[0010] In a preferred embodiment, the winding mechanism in this application includes a winding tension roller and a winding roller, which are arranged sequentially along the foil's travel direction.

[0011] In a preferred embodiment, in this application, a surface density detector is provided before the coating mechanism and / or after the drying mechanism. The surface density detector detects the surface density of the foil and / or coating by X-ray or β-ray.

[0012] In a preferred embodiment, a visual inspection device is provided after the coating mechanism and / or after the moisture detection mechanism in this application.

[0013] In a preferred embodiment, in this application, multiple correction devices and / or multiple traction mechanisms are spaced apart on the foil conveyor path. The traction mechanism includes traction rollers and pressure rollers, which are correspondingly pressed and arranged on both sides of the foil.

[0014] In a preferred embodiment, in this application, the coating mechanism, the drying mechanism, and the moisture detection mechanism are arranged in two sets along the foil conveyor belt direction, so as to sequentially perform the actions of coating slurry, baking coating, and detecting coating moisture content on the two opposite surfaces of the foil.

[0015] The electrode coating system provided in this application has the following technical advantages:

[0016] This electrode coating system includes a moisture detection mechanism after the drying mechanism. After at least one surface of the foil is coated with slurry by the coating mechanism and baked by the drying mechanism to remove the solvent and form a coating, the moisture detection mechanism can directly detect the water content of the coating. Thus, this application can accurately and quickly detect the water content of the coating without damaging the electrode structure. This not only reduces electrode waste but also lowers detection costs, making it an important means to ensure electrode quality, improve production efficiency, reduce production costs, and enhance production flexibility. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the electrode coating system of this application;

[0018] Figure 2 This is a schematic diagram of the moisture testing mechanism of this application.

[0019] Figure label:

[0020] 1. Unwinding mechanism; 11. Unwinding roller; 12. Unwinding tension roller; 2. Coating mechanism; 21. Coating die; 22. Traction roller; 23. Pressure roller; 3. Drying mechanism; 31. Oven; 32. Solvent concentration detection device; 4. Moisture detection mechanism; 41. Near-infrared luminometer; 42. Near-infrared sensor; 43. Analysis and processing system; 5. Rewinding mechanism; 51. Rewinding tension roller; 52. Rewinding roller; 6. Areal density meter; 7. Visual inspection device; 8. Web correction device; 9. Traction mechanism; 91. Traction roller; 92. Pressure roller; 10. Electrode. Detailed Implementation

[0021] To better understand and implement this application, the technical solutions in this application will be clearly and completely described below with reference to the accompanying drawings.

[0022] In the description of this application, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0023] Unless otherwise defined, 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 in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application.

[0024] See Figure 1This application provides an electrode coating system, comprising: an unwinding mechanism 1 for unwinding foil, a coating mechanism 2 for coating a slurry on at least one surface of the foil, a drying mechanism 3 for baking to remove solvent, a moisture detection mechanism 4 for detecting the water content of the coating, and a winding mechanism 5 for winding the electrode. The unwinding mechanism 1, coating mechanism 2, drying mechanism 3, moisture detection mechanism 4, and winding mechanism 5 are arranged sequentially along the conveying direction of the foil.

[0025] This electrode coating system can be used for coating production of both positive and negative electrodes. It requires only the selection of suitable copper or aluminum foil, the selection of appropriate positive or negative electrode slurry in the coating mechanism 2, and the setting of a suitable baking temperature in the drying mechanism 3. A moisture detection mechanism 4 is installed after the drying mechanism 3. After at least one surface of the foil is coated with slurry by the coating mechanism 2 and baked by the drying mechanism 3 to remove the solvent and form a coating, the moisture detection mechanism 4 can directly detect the water content of the coating. Thus, this application can accurately and quickly detect the water content of the coating without damaging the coating structure. This not only reduces waste of the electrode 10 but also lowers detection costs, making it an important means to ensure the quality of the electrode 10, improve production efficiency, reduce production costs, and enhance production flexibility. Specifically:

[0026] To ensure the quality of the electrode 10: After at least one surface of the foil is coated with slurry by the coating mechanism 2 and baked by the drying mechanism 3 to remove the solvent and form a coating, the moisture detection mechanism 4 can directly detect the water content of the coating. This allows for timely detection and correction of problems such as excessive water content that may occur during the coating process, preventing problems such as internal corrosion of the battery, damage to the SE I film, and Li F deposition caused by the reaction of water with the electrolyte. This ensures the performance and safety of the battery and improves the consistency of the battery.

[0027] Improve production efficiency: After at least one surface of the foil is coated with slurry by the coating unit 2 and baked by the drying unit 3 to remove the solvent to form a coating, the moisture detection unit 4 can quickly detect and provide feedback on the water content of the coating. This allows production personnel to adjust process parameters such as coating speed, slurry viscosity, and drying temperature in a timely manner based on the water content, thereby optimizing the coating process and improving production efficiency.

[0028] Reduced production costs: The moisture content of the coating can be quickly detected by the moisture detection device 4 during the coating process, so that the process can be adjusted in time to accurately control the moisture content of the electrode. This can reduce the scrap rate caused by excessive moisture content, and avoid unnecessary rework and repair costs, thereby reducing the overall production cost.

[0029] Enhanced production flexibility: The moisture content of the coating can be quickly detected by the moisture detection device 4 during the coating process, which allows production personnel to flexibly adjust the coating plan based on the detection data to meet the production needs of different batches and specifications of electrode sheets, thereby improving the flexibility and adaptability of production.

[0030] Specifically, the unwinding mechanism 1 includes an unwinding roller 11 and an unwinding tension roller 12, which are arranged sequentially along the foil's travel direction. The foil is wound on the unwinding roller 11, and one end of the foil is released from the unwinding roller 11 and connected to form a continuous strip. Then, it is fed into the unwinding tension roller 12 by a sheet-pulling device to adjust the tension and ensure tension stability during the coating process.

[0031] The coating mechanism 2 includes a coating die 21, a traction coating roller 22, and a pressure roller 23. The coating die 21 is positioned corresponding to the traction coating roller 22 to coat the slurry onto at least one surface of the foil. The traction coating roller 22 and the pressure roller 23 are positioned corresponding to the two sides of the foil. The coating die 21 is used to extrude the slurry and apply it to the foil by traction of the traction coating roller 22. The pressure roller 23 can roll the slurry to form a smooth and uniform coating. During the coating process, the coating amount, slurry viscosity, and whether to set blank areas for segmented coating are set in advance according to the coating requirements, and the coating is automated.

[0032] The drying unit 3 includes an oven 31 and a solvent concentration detection device 32. Coated foil passes through the oven 31 to bake and remove solvent. The solvent concentration detection device 32 is located at the outlet of the oven 31. The coated foil enters the oven 31 for baking to remove solvent from the slurry, allowing the coating to adhere firmly to the foil. Baking temperature, baking time, etc., are preset according to production requirements, and automated baking is controlled. The solvent concentration detection device 32 can detect the concentration of solvent in the coating after baking to determine the degree of solvent removal. Different slurries use different solvents, and the solvent concentration detection device 32 can be selected according to the type of slurry.

[0033] Combination Figure 2The moisture detection mechanism 4 includes a near-infrared luminometer 41, a near-infrared sensor 42, and an analysis and processing system 43. The near-infrared luminometer 41 is positioned to emit near-infrared light corresponding to the coating of the foil. The near-infrared sensor 42 is located on the transmission path of the near-infrared light reflected from the coating and is electrically connected to the analysis and processing system 43. The near-infrared luminometer 41 emits light of a specific wavelength, which, after passing through lenses, filters, and mirrors, is emitted as parallel light onto the coating. The coating absorbs part of the infrared light, while the remaining infrared light is scattered and focused by a concave mirror onto the near-infrared sensor 42. The near-infrared sensor 42 transmits the information to the analysis and processing system 43, where a digital processor processes the reference and measurement light signals to quickly determine the water content. Thus, the control system can promptly adjust production parameters after determining the water content.

[0034] Combination Figure 1 The winding mechanism 5 includes a winding tension roller 51 and a winding roller 52, which are arranged sequentially along the feeding direction of the foil. The winding tension roller 51 is used to adjust the winding tension so that the winding roller 52 can smoothly wind up the electrode sheet 10.

[0035] In addition to the above structure, an areal density detector 6 is provided before the coating unit 2 and / or after the drying unit 3. The areal density detector 6 uses X-ray or β-ray rays to detect the areal density of the foil and / or coating. The areal density detector 6 can detect the areal density of the foil and its surface coating to determine whether it meets the coating requirements.

[0036] A visual inspection device 7 is provided after the coating unit 2 and / or after the moisture detection unit 4. The visual inspection device 7 can use equipment such as CCD to acquire information such as the width and appearance of the coating in order to quickly identify defects.

[0037] Multiple correction devices 8 and / or multiple traction mechanisms 9 are spaced apart along the foil conveyor path. The traction mechanism 9 includes a traction roller 91 and a pressure roller 92, which are correspondingly pressed and arranged on both sides of the foil. The correction devices 8 and traction mechanisms 9 can position the foil conveyor path to prevent deviation from affecting the coating effect.

[0038] Furthermore, two sets of coating mechanism 2, drying mechanism 3, and moisture detection mechanism 4 are sequentially arranged along the foil conveyor belt direction to sequentially coat the foil with slurry, bake the coating, and detect the moisture content of the coating on the opposite surfaces of the foil. The arrangement of the two sets of coating mechanism 2, drying mechanism 3, and moisture detection mechanism 4 allows for coating one surface of the foil with slurry, drying, and moisture content detection, followed by coating the other surface of the foil with slurry, drying, and moisture content detection, thereby ensuring that both opposite surfaces of the foil are coated.

[0039] The following is the process flow of the electrode coating system of this application:

[0040] The foil is wound on the unwinding roller 11, and one end of the foil is released from the unwinding roller 11 and connected to form a continuous strip. Then, it is fed into the unwinding tension roller 12 by the sheet pulling device to adjust the tension and ensure the tension stability during the coating process.

[0041] Then, guided precisely to the position of the areal density detector 6 by the traction mechanism 9 and the correction device 8, the areal density of the foil is detected by X-ray or β-ray.

[0042] Next, guided by the correction device 8, the foil is precisely positioned at the coating mechanism 2, where the coating die 21 coats the first surface of the foil with slurry, and the traction coating roller 22 and pressure roller 23 work together to form a smooth and uniform first coating. At the same time, the visual inspection device 7 inspects the size and appearance of the first coating to remove defective products.

[0043] Next, it is sent to the work station of the drying unit 3, where the first coating is baked in the oven 31 to remove the solvent in the slurry, so that the first coating can adhere firmly to the foil. The solvent concentration detection device 32 is used to detect the concentration of solvent in the first coating after baking to determine the degree of solvent removal.

[0044] Then, guided precisely by the correction device 8 and the traction mechanism 9, it reaches the position of the surface density detector 6 so that the surface density of the first coating can be detected by X-Ray or β-Ray rays.

[0045] Next, it is sent to the moisture detection unit 4. The near-infrared luminometer 41 can emit light of a specific wavelength. After passing through the lens, filter, reflector and other components, the parallel light is emitted onto the coating. After the coating absorbs part of the infrared light, the other part of the infrared light is scattered and focused into the near-infrared sensor 42 by the concave mirror. The near-infrared sensor 42 can transmit the information to the analysis and processing system 43, so that the reference light and the measuring light of the light signal can be processed by the digital processor, thereby quickly obtaining the water content. This allows the control system to adjust the production parameters in a timely manner after knowing the water content.

[0046] Next, the size and appearance of the first coating are inspected again using the visual inspection device 7 to remove defective products;

[0047] Then, guided precisely to the second workstation by the correction device 8, the above operation is repeated on the other surface of the foil to obtain the second coating.

[0048] After both sides of the foil are coated, the foil is guided into the winding mechanism 5 by the correction device 8 for winding, and then transported to the next process for compaction and slitting.

[0049] In this way, the electrode coating system integrates near-infrared detection technology with the coating mechanism 2, the drying mechanism 3 and the data processing system to achieve automated and intelligent detection of water content, enabling real-time control of the electrode water content and improving the consistency of the electrode.

[0050] The technical means disclosed in this application are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make several improvements and modifications without departing from the principles of this application, and these improvements and modifications are also considered to be within the scope of protection of this application.

Claims

1. An electrode coating system, characterized in that, include: The unwinding mechanism (1), the coating mechanism (2), the drying mechanism (3), the moisture detection mechanism (4), and the winding mechanism (5) for unwinding foil are arranged sequentially along the conveying direction of the foil. The drying mechanism (3) includes an oven (31) and a solvent concentration detection device (32). The coated foil passes through the oven (31) to bake and remove the solvent. The solvent concentration detection device (32) is located at the outlet of the oven (31).

2. The electrode coating system according to claim 1, characterized in that: The unwinding mechanism (1) includes an unwinding roller (11) and an unwinding tension roller (12), which are arranged sequentially along the feeding direction of the foil.

3. The electrode coating system according to claim 1, characterized in that: The coating mechanism (2) includes a coating die (21), a traction coating roller (22) and a pressure roller (23). The coating die (21) is positioned corresponding to the traction coating roller (22) to coat the slurry onto at least one surface of the foil. The traction coating roller (22) and the pressure roller (23) are positioned corresponding to the two sides of the foil.

4. The electrode coating system according to claim 1, characterized in that: The moisture detection mechanism (4) includes a near-infrared luminometer (41), a near-infrared sensor (42), and an analysis and processing system (43). The near-infrared luminometer (41) is configured to emit near-infrared light corresponding to the coating of the foil. The near-infrared sensor (42) is located on the transmission path of the near-infrared light reflected by the coating. The near-infrared sensor (42) is electrically connected to the analysis and processing system (43).

5. The electrode coating system according to claim 1, characterized in that: The winding mechanism (5) includes a winding tension roller (51) and a winding roller (52), which are arranged sequentially along the feeding direction of the foil.

6. The electrode coating system according to any one of claims 1-5, characterized in that: A surface density detector (6) is provided before the coating mechanism (2) and / or after the drying mechanism (3), the surface density detector (6) detecting the surface density of the foil and / or coating by X-ray or β-ray.

7. The electrode coating system according to any one of claims 1-5, characterized in that: A visual inspection device (7) is provided after the coating mechanism (2) and / or after the moisture detection mechanism (4).

8. The electrode coating system according to any one of claims 1-5, characterized in that: Multiple correction devices (8) and / or multiple traction mechanisms (9) are provided at intervals along the foil conveyor path. The traction mechanism (9) includes a traction roller (91) and a pressure roller (92). The traction roller (91) and the pressure roller (92) are respectively squeezed and arranged on both sides of the foil.

9. The electrode coating system according to any one of claims 1-5, characterized in that: The coating mechanism (2), the drying mechanism (3), and the moisture detection mechanism (4) are arranged in two sets along the foil conveying direction to sequentially coat the foil with slurry, bake the coating, and detect the water content of the coating on the opposite two surfaces of the foil.

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