Lithium battery diaphragm drying unit and coating drying device

Abstract

The utility model relates to battery diaphragm technical field more specifically, relate to a kind of lithium battery diaphragm drying unit and coating drying device, drying unit includes box, at least one partition is provided in the box, the partition separates the box into at least two chambers, each chamber is respectively provided with heat source, the diaphragm is sequentially laid through each chamber. Box is separated to form each chamber by partition, diaphragm can be dried by passing each chamber, compact structure between each chamber, can improve drying efficiency. Since at least two chambers are respectively provided with heat source, different heat source combinations can be selected according to specific diaphragm standard to carry out drying, improve drying efficiency. Coating drying device includes the above drying unit.

Description

Technical Field

[0001] This utility model relates to the field of battery separator technology, and more specifically, to a lithium battery separator drying unit and a coating and drying device. Background Technology

[0002] Lithium-ion batteries possess excellent volumetric and gravimetric energy densities, making them considered the most promising energy storage technology, and they are widely used in various fields. In recent years, the development of new energy vehicles has gradually replaced the market position of gasoline vehicles, and with the popularization of new energy vehicles, lithium batteries, an important component, are also being used more and more.

[0003] The separator, one of the four key materials in lithium-ion batteries, is a crucial component. Its primary function is to isolate electron transfer between the positive and negative electrodes, preventing short circuits, while allowing ions to pass through. The performance of the separator directly impacts the battery's production cost and safety. A high-performance separator can significantly improve the capacity, cycle performance, and safety of a lithium-ion battery. The separator's performance determines the electrolyte wetting efficiency, battery interface structure, and internal resistance. Depending on the battery type and application, the base separator and its coating will vary.

[0004] Because the separator has various coatings, it needs to be dried to avoid high moisture content affecting battery performance. However, current drying equipment has low efficiency and needs improvement. Utility Model Content

[0005] To overcome the problem of low drying efficiency of lithium battery separators in the prior art, this utility model provides a lithium battery separator drying unit that can improve the drying efficiency of the separator.

[0006] Another objective of this invention is to provide a lithium battery separator coating and drying device.

[0007] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is: a lithium battery separator drying unit, including a box body, wherein at least one partition is provided inside the box body, the partition divides the box body into at least two chambers, each of the chambers is provided with a heat source, and the separator is arranged sequentially through each of the chambers.

[0008] In this invention, the housing is divided into chambers by partitions, and the diaphragm can pass through each chamber for drying. The chambers are compactly structured, which improves drying efficiency. Each chamber is equipped with a heat source for drying, allowing for the selection of appropriate heat source combinations based on specific diaphragm standards, thereby improving drying efficiency.

[0009] Furthermore, each of the aforementioned chambers is equipped with a guide roller.

[0010] In this scheme, the diaphragm is guided by multiple guide rollers so that it passes through the drying unit for drying.

[0011] Furthermore, each of the guide rollers is arranged horizontally in the chamber.

[0012] In this scheme, the diaphragm is dried by passing through the chamber in a horizontal direction using horizontally arranged guide rollers.

[0013] Furthermore, the guide roller includes at least a first guide roller and a second guide roller, the first guide roller and the second guide roller being disposed at different height positions within the cavity so that the guide rollers are arranged along a bending path.

[0014] In this scheme, by setting a first guide roller and a second guide roller with different heights, the diaphragm can pass through the chamber along a bending path for drying.

[0015] Furthermore, at least some of the guide rollers in the cavity are arranged horizontally, and at least some of the guide rollers in the cavity are arranged along a bending path.

[0016] In this design, the diaphragm passes through part of the chamber horizontally and through part of the chamber by bending, which can be combined with different drying methods to improve drying efficiency.

[0017] Furthermore, an enclosing region is formed between the guide rollers arranged along the bending path, and the heat source is located within the enclosing region.

[0018] In this solution, a surrounding area is formed by guide rollers, which allows the diaphragm to surround the heat source, thereby improving drying efficiency.

[0019] Furthermore, the housing is provided with an air inlet and an air outlet, with the air inlet located at the top of the first chamber and the air outlet located at the top of the last chamber.

[0020] In this design, hot air is introduced into the housing through the air inlet and the gas is discharged through the air outlet.

[0021] Furthermore, at least two of the chambers are provided with different heat sources, which are at least one of an infrared dryer, a microwave dryer, and an electric heater.

[0022] In this scheme, since at least two chambers are equipped with different heat sources, different heat sources can be selected and combined for different diaphragms to improve drying efficiency.

[0023] Furthermore, the drying unit also includes a controller, and each of the chambers is equipped with a temperature sensor, and each temperature sensor and heat source are electrically connected to the controller.

[0024] In this solution, the temperature inside the chamber can be monitored by a temperature sensor, and the temperature information can be obtained by a controller to adjust the power of the heat source as needed.

[0025] This utility model also provides a lithium battery separator coating and drying device, including an unwinding mechanism, a coating unit, any of the above-mentioned drying units, and a winding mechanism, wherein the separator is sequentially laid through the unwinding unit, the coating unit, the drying unit, and the winding unit.

[0026] In this solution, the coating and drying device uses the aforementioned drying unit, thus achieving high drying efficiency.

[0027] Compared with the prior art, the beneficial effects of this utility model are:

[0028] I. The lithium battery separator drying unit of this utility model divides the box into chambers by partitions, and the separator can pass through each chamber for drying. The structure between each chamber is compact, which can improve the drying efficiency.

[0029] II. The lithium battery separator drying unit of this utility model has an enclosing area formed by some guide rollers arranged along the bending path, which makes the separator surround the heat source, thus improving the drying efficiency.

[0030] Third, since at least two chambers are equipped with different heat sources, different combinations of heat sources can be selected for drying according to specific diaphragm standards, thereby improving drying efficiency. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the structure of the drying unit of the present invention in the first embodiment;

[0032] Figure 2 This is a schematic diagram of the structure of the drying unit of the present invention in the second embodiment;

[0033] Figure 3 These are schematic diagrams of the third and fourth embodiments of the drying unit of this utility model;

[0034] Figure 4 This is a schematic diagram of the fifth embodiment of the drying unit of this utility model;

[0035] Figure 5 This is a schematic diagram of the coating and drying device of this utility model.

[0036] In the attached diagram: 1. Housing; 11. Chamber; 12. Enclosed area; 2. Partition; 3. Heat source; 4. First guide roller; 5. Second guide roller; 6. Air inlet; 7. Air outlet; 8. Dustproof net; 9. Temperature sensor; 100. Diaphragm; 200. Unwinding mechanism; 201. Dust removal roller; 202. First tension roller; 300. Coating unit; 400. Drying unit; 500. Rewinding mechanism; 501. Traction roller; 502. Second tension roller; 503. Correction roller. Detailed Implementation

[0037] The accompanying drawings are for illustrative purposes only and should not be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the actual dimensions of the product. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings. The positional relationships described in the drawings are for illustrative purposes only and should not be construed as limiting this patent.

[0038] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "long," and "short" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0039] The lithium battery separator will be introduced below to make the technical solution of this utility model easier to understand.

[0040] The separator used in lithium batteries includes a base membrane and a coating slurry coated on the surface of the base membrane. Depending on the application scenario of the separator, the coating slurry is uniformly coated on at least one side of the separator. After the coating slurry is dried, it forms a coating that adheres to the surface of the base membrane.

[0041] The base film can be made of various materials, such as polyethylene, polypropylene, polyvinylidene fluoride, polyimide, and polyolefin copolymers, or one or more of these.

[0042] The coating slurry includes organic / inorganic substances and organic solvents. The various components are formulated according to different formulations to form the slurry. The organic components include: polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene (PVDAF-HFP), polymethyl methacrylate (PMMA), polyvinylpyrrolidone (PVP), polyacetylimide (PEI), polyvinyl alcohol (PVA), polyallylamine (PAH), and polyacrylic acid (PAA), etc.

[0043] The inorganic component can be selected from alumina, boehmite, silicon dioxide, zirconium dioxide, or other solid electrolyte materials such as lithium titanium aluminum phosphate, lithium lanthanum zirconium oxide, and lithium lanthanum zirconium titanium oxide.

[0044] Solvents may be at least one of water, methanol, ethanol, isopropanol, acetone, butanone, dichloroethane, tetrahydrofuran, ethyl acetate, N-methylpyrrolidone, and dimethylacetamide.

[0045] After the slurry is coated onto the base membrane using different coating methods, a coated membrane can be formed. However, some solvent remains on the membrane, which can affect the membrane's performance.

[0046] In related technologies, in order to ensure the drying effect and efficiency of the coated diaphragm during the drying process, a higher temperature is usually used to remove residual solvents and moisture. However, a higher temperature can cause the diaphragm to shrink or even close its pores, or to produce wrinkles on the diaphragm surface. A lower temperature cannot achieve the desired result.

[0047] Most current diaphragm drying equipment uses hot air drying. While this method can remove most of the solvent from the diaphragm, it suffers from low drying efficiency and excessive energy consumption for highly polar ceramic particles, making it difficult to meet increasingly stringent standards for diaphragm moisture control. Therefore, a new drying unit needs to be designed to achieve higher efficiency and better drying results.

[0048] The present solution will be further described below with reference to the accompanying drawings and specific embodiments:

[0049] Example 1

[0050] refer to Figure 1 The figure shows the first embodiment of this utility model. This embodiment discloses a lithium battery separator drying unit, including a housing 1, with a partition 2 disposed inside the housing 1, dividing the housing 1 into two chambers 11 by the partition 2, and a channel for the separator 100 to pass through is provided between each chamber 11. A heat source 3 is disposed in each chamber 11, and different heat sources 3 are disposed in the two chambers 11.

[0051] The chamber 1 is roughly rectangular, and the partition 2 is vertically arranged in the chamber 1 to separate the chamber 1 into various chambers 11. The partition 2 is used to eliminate the influence between adjacent heat sources 3. Through holes for the diaphragm 100 to pass through are opened in the partition 2. Through holes for the diaphragm 100 to pass through are also opened at the front and rear ends of the chamber 1, so that the diaphragm 100 can pass through the chamber 1 and the partition 2 for drying.

[0052] Each chamber 11 is provided with a guide roller. In this embodiment, each guide roller is arranged horizontally in the chamber 11, and the diaphragm 100 passes through the chamber 11 in a horizontal direction for drying by means of the horizontally arranged guide roller.

[0053] In this embodiment, the housing 1 is provided with an air inlet 6 and an air outlet 7, which are respectively located on the top of the first and last chambers 11. Both the air inlet 6 and the air outlet 7 are provided with dustproof nets 8. Hot air is sent into the housing 1 through the air inlet 6 and the gas is discharged through the air outlet 7, while dust is blocked by the dustproof nets 8.

[0054] In this embodiment, fans can be installed at the air inlet 6 and air outlet 7 to promote air circulation and improve drying efficiency. Alternatively, an external fan can be used to supply hot air to the air inlet 6 and discharge moisture-containing gas from the air outlet 7. The hot air can accelerate the removal of most of the moisture from the surface of the diaphragm 100.

[0055] In this embodiment, the drying unit 400 also includes a controller. Each chamber 11 is equipped with a temperature sensor 9, and each temperature sensor 9 and heat source 3 are electrically connected to the controller. The temperature sensor 9 can monitor the temperature inside the chamber 11, and the controller can obtain the temperature information and adjust the power of the heat source 3 as needed to prevent excessive temperature from causing adverse changes in the diaphragm 100.

[0056] Optionally, heat source 3 can be at least one of an infrared dryer, a microwave dryer, and an electric heater. In actual use, different heat sources 3 can be selected according to different drying requirements of the diaphragm 100. An electric heater can directly heat the air, allowing the moisture on the diaphragm surface to dry quickly. A microwave dryer uses electromagnetic wave heating, which does not require a heat transfer medium and heats from the inside of the object, resulting in rapid temperature rise, high efficiency, a significantly shortened drying cycle, and reduced energy consumption. Due to the rapid adjustment of microwave power and the absence of inertia, it is easy to control in real time, and the temperature can be adjusted arbitrarily. An infrared dryer uses electrical energy to generate infrared rays, causing the object being dried to absorb and penetrate from the surface to the interior. It has a high drying rate and high thermal efficiency, and does not leave shadows during irradiation.

[0057] For example, in this embodiment, taking the illustrated direction as an example, the first heat source 3 is an infrared dryer, and the second heat source 3 is an electric heater. This allows both the surface and interior of the coating to be effectively dried, preventing insufficient removal of internal moisture.

[0058] Example 2

[0059] refer to Figure 2 The figure shows the second embodiment, which is similar to the first embodiment. The housing 1 is divided into two chambers 11 by a partition 2. The difference is that in this embodiment, the guide rollers include a first guide roller 4 and a second guide roller 5. The first guide roller 4 and the second guide roller 5 are arranged at different heights in the chamber 11 so that the guide rollers are arranged along a bending path, so that the diaphragm 100 can pass through the chamber 11 along the bending path for drying.

[0060] In this embodiment, the roller at the same height as the through hole in the partition is defined as the first guide roller 4, and the roller below the first guide roller 4 is defined as the second guide roller 5. Each of the chambers 11 shown in the figure has two first guide rollers 4 and two second guide rollers 5. In chamber 11, the two first guide rollers 4 are located on both sides of the upper middle part of chamber 11, and the two second guide rollers 5 are located below the middle of the two first guide rollers 4. The diaphragm 100 passes through each guide roller in sequence to form a U-shaped structure. The guide rollers in both chambers 11 are arranged in the same manner, and the heat source 3 is located inside the U-shaped structure, which can improve the drying effect.

[0061] In this embodiment, taking the illustrated direction as an example, the first heat source 3 is an electric heater, and the second heat source 3 is a microwave dryer. The electric heater can efficiently remove most of the moisture from the outside to the inside, and the microwave dryer can further remove the moisture inside the coating. The U-shaped structure can extend the residence time of the diaphragm in the chamber and make full use of the energy of the microwave dryer.

[0062] Example 3

[0063] refer to Figure 3 The figure shows the third embodiment, which is similar to embodiment 1 or 2. In this embodiment, the box 1 is divided into two chambers 11 by a partition 2. The guide rollers include a first guide roller 4 and a second guide roller 5. The first guide roller 4 and the second guide roller 5 are set at different height positions in the chamber 11 so that the guide rollers are arranged along the bending path, so that the diaphragm 100 can pass through the chamber 11 along the bending path for drying.

[0064] The difference lies in this embodiment. Taking the illustrated direction as an example, the first chamber 11 from left to right only has a first guide roller 4, allowing the diaphragm 100 to pass through the first chamber 11 horizontally. The second chamber 11 has a first guide roller 4 and a second guide roller 5. The two first guide rollers 4 are located on both sides of the upper middle part of the chamber 11, and the two second guide rollers 5 are located below the middle of the two first guide rollers 4. The diaphragm 100 passes through each guide roller in sequence to form a U-shaped structure.

[0065] In this embodiment, taking the illustrated direction as an example, the first heat source 3 from left to right is an infrared dryer, and the second heat source 3 is a microwave dryer. The infrared dryer mainly dries the surface moisture, while the microwave dryer further removes moisture from the coating, preventing uneven temperature distribution from causing the diaphragm to shrink.

[0066] Example 4

[0067] refer to Figure 3The illustration shows the fourth embodiment, which is similar to embodiment 3, except that, taking the illustrated direction as an example, the first heat source 3 from left to right is an electric heater, and the second heat source 3 is a microwave dryer. Using an electric heater can quickly reduce the moisture content of the diaphragm to a lower level, making it suitable for diaphragms with different moisture contents compared to embodiment 3.

[0068] Example 5

[0069] refer to Figure 4 The figure shows the fifth embodiment, which is similar to the third embodiment, except that in this embodiment, the box 1 is provided with two partitions 2, which divide the box 1 into three chambers 11, and a heat source 3 is provided in each chamber 11.

[0070] Taking the direction shown in the figure as an example, the guide rollers in the first chamber 11 and the second chamber 11 from left to right are arranged in the same way as in embodiment 3. The third chamber 11 is only provided with the first guide roller 4, so that the diaphragm 100 passes through the third chamber 11 in the horizontal direction.

[0071] In this embodiment, the first heat source 3 is an electric heater, the second heat source 3 is a microwave dryer, and the third heat source 3 is an infrared dryer. This embodiment can be used to achieve extremely low moisture content when the coating is thick and has a high moisture content.

[0072] Example 6

[0073] refer to Figures 1 to 5 This embodiment discloses a lithium battery separator coating and drying apparatus, including an unwinding mechanism 200, a coating unit 300, a drying unit 400, and a winding mechanism 500. The separator is sequentially arranged through the unwinding mechanism 200, the coating unit 300, the drying unit 400, and the winding mechanism 500. The drying unit 400 can be any one of the drying units 400 in embodiments 1 to 4, or a drying unit 400 obtained by recombining embodiments 1 to 4. The internal structure of the drying unit 400 will not be described here.

[0074] Specifically, the base film is wound onto the unwinding unit 200. After being unwound from the unwinding unit 200, the base film passes through the guide roller, the dust removal roller 201, and the first tension roller 202 before entering the coating unit 300. The coating unit 300 uses an existing separator coating unit, the specific structure of which is known to those skilled in the art. The coating unit 300 can coat at least one side of the base film with a coating slurry. The coated base film passes through the traction roller 501 into the drying unit 400. After being dried in the drying unit 400, the coating slurry adheres to the surface of the base film, forming a separator 100 for lithium batteries together with the base film. The separator 100, delivered from the drying unit 400, passes through the traction roller 501, the second tension roller 502, and the correction roller 503 before being received by the winding mechanism 500. The traction rollers 501 located at the outlet of the drying unit 400 are a pair, one above the other, which can compact the coating, making the coating thickness distribution more uniform to a certain extent and facilitating winding.

[0075] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A lithium battery separator drying unit, characterized in that: The device includes a housing (1), which has at least one partition (2) inside. The partition (2) divides the housing (1) into at least two chambers (11). Each chamber (11) is provided with a heat source (3). The diaphragm is arranged sequentially through each chamber (11). At least two chambers (11) are provided with different heat sources (3). The heat source (3) is at least one of an infrared dryer, a microwave dryer, and an electric heater.

2. The lithium battery separator drying unit according to claim 1, characterized in that: Each of the chambers (11) is provided with a guide roller.

3. The lithium battery separator drying unit according to claim 2, characterized in that: Each of the guide rollers is arranged horizontally in the chamber (11).

4. The lithium battery separator drying unit according to claim 2, characterized in that: The guide rollers include at least a first guide roller (4) and a second guide roller (5), the first guide roller (4) and the second guide roller (5) being disposed at different height positions within the chamber (11) so that the guide rollers are arranged along a bending path.

5. The lithium battery separator drying unit according to claim 4, characterized in that: The guide rollers in at least a portion of the chamber (11) are arranged horizontally, and the guide rollers in at least a portion of the chamber (11) are arranged along a zigzag path.

6. The lithium battery separator drying unit according to claim 5, characterized in that: An enclosing region (12) is formed between the guide rollers arranged along the bend path, and the heat source (3) is located in the enclosing region (12).

7. The lithium battery separator drying unit according to any one of claims 1 to 6, characterized in that: The housing is provided with an air inlet (6) and an air outlet (7). The air inlet (6) is located at the top of the first chamber (11), and the air outlet (7) is located at the top of the last chamber (11).

8. The lithium battery separator drying unit according to any one of claims 1 to 6, characterized in that: The drying unit also includes a controller, and each of the chambers (11) is provided with a temperature sensor (9), and each of the temperature sensors (9) and the heat source (3) is electrically connected to the controller.

9. A lithium battery separator coating and drying apparatus, characterized in that: The diaphragm is arranged sequentially through the unwinding mechanism (200), the coating unit (300), the drying unit (400) as described in any one of claims 1 to 8, and the winding mechanism (500).

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