Lithium ion spraying PVDF diaphragm production device and method

Abstract

The invention discloses a lithium ion spraying PVDF (Polyvinylidene Fluoride) diaphragm production device, which comprises an unwinding unit, a coating unit, a coating unit and a drying unit, the pretreatment unit is used for cleaning and activating the base material released by the unwinding unit, and the cleaned and activated diaphragm base material is a pretreated base material; the spraying unit is used for spraying paint to the pretreated base material, the spraying unit is provided with a spraying rotor, and the spraying rotor adopts an independent power rotor and is used for adjusting the spraying amount of the paint; and the drying unit is used for curing the coating on the surface of the pretreated base material to form a diaphragm finished product. In the invention, the diaphragm coating is made of the PVDF material, and the PVDF has excellent chemical stability, thermal stability and mechanical strength, and is matched with the production process in the application to modify the diaphragm material, so that the quality of the diaphragm is improved, and the safety of the battery can be improved.

Description

Technical Field

[0001] The invention relates to the technical field of lithium ion battery manufacturing, and in particular to a lithium ion spraying PVDF diaphragm production device and method. Background Art

[0002] With the rapid development of new energy technologies, lithium-ion batteries, as efficient and environmentally friendly energy storage devices, have been widely used in portable electronic devices, electric vehicles, and large-scale energy storage systems. The performance of lithium-ion batteries depends largely on the quality and characteristics of their internal components. The separator, as one of the key components inside the battery, has the important functions of isolating positive and negative electrode materials, preventing short circuits, and allowing lithium ions to pass through.

[0003] Traditional lithium-ion battery separator materials, such as polyolefin materials, although chemically stable and mechanically strong, are still prone to thermal shrinkage under high temperature conditions, which not only affects the separator quality and battery use, but also increases the safety risks of the battery. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of the above-mentioned background technology and to provide a lithium ion sprayed PVDF diaphragm production device and method.

[0005] The purpose of the present invention can be achieved through the following technical solutions:

[0006] A lithium ion spray PVDF diaphragm production device comprises: an unwinding unit, the unwinding unit is used to release a diaphragm substrate; a pretreatment unit, the pretreatment unit is used to clean and activate the substrate released by the unwinding unit, and the diaphragm substrate after the cleaning and activation treatment is the pretreated substrate; a spraying unit, the spraying unit is used to spray paint on the pretreated substrate, the spraying unit is provided with a spraying rotor, and the spraying rotor adopts an independent power rotor for adjusting the spraying amount of the paint; a drying unit, the drying unit is used to cure the paint on the surface of the pretreated substrate to form a diaphragm product; a winding unit, the winding unit is used to roll up and store the diaphragm product; the unwinding unit, the pretreatment unit, the spraying unit and the drying unit are all provided with conveying rollers for conveying materials; the unwinding unit stably releases the diaphragm substrate to the pretreatment unit, the pretreatment unit cleans and activates the diaphragm substrate and then conveys it to the spraying unit for spraying paint, and then the diaphragm product is made by the drying unit and then conveyed to the winding unit for winding.

[0007] As a further solution of the present invention: the pretreatment unit includes a cleaning mechanism, and the cleaning mechanism is a cleaning brush for removing pollutants on the surface of the diaphragm substrate.

[0008] As a further solution of the present invention: the pretreatment unit also includes a plasma treatment chamber, the plasma treatment chamber is connected to equal electrodes, and a plasma generator is arranged on the top of the equal electrodes.

[0009] As a further solution of the present invention: one side of the equal electrode is connected to the gas supply mechanism, and the other side is connected to the gas exhaust mechanism.

[0010] As a further solution of the present invention: the spraying unit is provided with a support rod, a plurality of nozzles are provided on the support rod, and a spraying rotor is provided in the nozzle.

[0011] As a further solution of the present invention: the unwinding unit and the rewinding unit are both provided with a tension control system for tensioning the material.

[0012] A method for producing a PVDF diaphragm using lithium ion spraying, comprising:

[0013] S1, the unwinding unit releases the diaphragm substrate at a preset speed and adjusts the surface tension of the diaphragm substrate;

[0014] S2, the pretreatment unit performs surface cleaning and activation treatment on the diaphragm substrate to form a pretreated substrate;

[0015] S3, spraying the PVDF solution on the pretreated substrate at a uniform speed through a spraying unit to form a coating on the surface of the pretreated substrate;

[0016] S4, the drying unit dries the coating on the surface of the pre-treated substrate at a preset temperature to solidify the coating to form a finished diaphragm;

[0017] S5. The winding unit winds up the finished diaphragm for storage.

[0018] As a further solution of the present invention: in step S3, the mass fraction of the PVDF solution is 10% to 15%.

[0019] Beneficial effects of the present invention:

[0020] (1) In the present invention, the diaphragm coating is made of PVDF material. Since PVDF has excellent chemical stability, thermal stability and mechanical strength, the diaphragm material is modified in combination with the production process in this application, which not only improves the diaphragm quality but also improves the safety of the battery.

[0021] (2) In the present invention, the design of the independent power rotor ensures the uniformity and consistency of the coating. Compared with the traditional spraying technology, the PVDF solution can be sprayed more evenly and efficiently. This improvement reduces the waiting and adjustment time in the production process and further improves the production efficiency.

[0022] (3) In the present invention, the improvement of coating uniformity and consistency can also lead to improvement of porosity and air permeability.

[0023] (4) In the present invention, due to the improvement of coating uniformity and curing quality, the qualified rate of diaphragm products is also effectively improved. The improvement of production efficiency and the increase in the qualified rate of diaphragm products effectively reduce the production cost per unit product. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will be further described below in conjunction with the accompanying drawings.

[0025] Figure 1 It is a structural schematic diagram of the lithium ion spraying PVDF diaphragm production device of the present invention;

[0026] Figure 2 yes Figure 1 Schematic diagram of the structure of the pre-processing unit

[0027] Figure 3 yes Figure 1 A schematic diagram of the side structure of the middle support rod;

[0028] Figure 4 It is a flow chart of the lithium ion ceramic diaphragm aluminum oxide recovery method of the present invention.

[0029] In the figure: 1. unwinding unit; 2. pretreatment unit; 21. cleaning mechanism; 22. air supply mechanism; 23. equal electrodes; 24. plasma generator; 25. exhaust mechanism; 26. plasma treatment chamber; 3. spraying unit; 31. support rod; 32. spraying rotor; 4. drying unit; 5. winding unit. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 As shown, the present invention is a lithium ion spray PVDF diaphragm production device, comprising: an unwinding unit 1, the unwinding unit 1 is used to release the diaphragm substrate, and the unwinding unit 1 is also provided with a tension control system for tensioning the diaphragm substrate.

[0032] Among them, the tension control system includes sensors, controllers, drivers and actuators. The sensors can monitor the tension of the diaphragm substrate in real time to prevent deformation and damage of the substrate. After receiving the data from the sensor, the controller analyzes and processes it and decides how to adjust the tension of the diaphragm substrate. The controller generally adopts PLC or microcontroller (the use of controller is a routine choice for technicians in this field, so it will not be described in detail here). The driver adjusts the tension according to the instructions of the controller. The driver usually adopts a motor or a cylinder, and the actuator is a reel or a tensioning wheel, which can directly affect the tension of the diaphragm substrate.

[0033] When working, the tension control system can maintain uniform tension to prevent damage and deformation. It can also adjust the tension based on real-time feedback to cope with changes in the production process. It can also reduce downtime, thereby improving the overall efficiency of the production line.

[0034] See also Figure 1-Figure 2 As shown, the device also includes a pretreatment unit 2, which is used to perform plasma treatment on the substrate released by the unwinding unit 1. Plasma treatment is a technology that uses the physical and chemical properties of plasma to treat the surface of the diaphragm substrate. Plasma is a gas state composed of ions, free electrons and neutral particles, in which the particles have sufficient energy to carry out various chemical reactions and physical changes. The diaphragm substrate after plasma treatment is the pretreatment substrate.

[0035] Specifically, the pretreatment unit 2 includes a cleaning mechanism 21, which is a cleaning brush for removing pollutants on the surface of the membrane substrate. In other embodiments, the cleaning mechanism 21 can use ultrasonic cleaning, solvent cleaning, airflow cleaning, or chemical spray cleaning.

[0036] The pretreatment unit 2 also includes a plasma processing chamber 26, which is connected to the iso-electrode 23. A plasma generator 24 is arranged on the top of the iso-electrode 23. One side of the iso-electrode 23 is connected to a gas supply mechanism 22, and the other side is connected to an exhaust mechanism 25, wherein the gas supply mechanism 22 is connected to an external argon source or a nitrogen source.

[0037] In this embodiment, the gas supply mechanism 22 provides gas to the plasma processing chamber 26, and the plasma generator 24 provides high-frequency power to excite the gas to form plasma. During this process, the gas supply mechanism 22 continuously supplies gas to maintain the stability and characteristics of the plasma. The isoelectric electrode 23 enables a uniform electric field to be formed in the plasma processing chamber 26, ensuring that the plasma is evenly distributed throughout the chamber. The active particles (ions, free radicals, atoms) in the plasma react with the surface of the diaphragm material to activate the diaphragm material to change the surface chemical properties, roughness, hydrophilicity or lipophilicity of the diaphragm material. The byproducts and waste gas in the plasma processing chamber 26 are discharged through the exhaust mechanism 25 to prevent pollution accumulation and keep the environment in the plasma processing chamber 26 clean.

[0038] It can be understood that the pretreatment unit 2 not only removes impurities on the surface of the diaphragm substrate, but also further enhances the adhesion performance of its surface (activation treatment), providing ideal surface conditions for the subsequent attachment of the PVDF solution.

[0039] See also Figure 1 , Figure 3 As shown, a spray unit 3 is used to spray paint onto the pretreated substrate to form a coating on the surface of the pretreated substrate. The paint adopts PVDF solution. The spray unit 3 is a container for holding the paint. The spray unit 3 is provided with a support rod 31. A plurality of nozzles are provided on the support rod 31. Pipes connected to the nozzles extend into the paint in the container. A pump body with a spray rotor 32 is provided in the nozzle. The spray rotor 32 adopts an independent power rotor for adjusting the spraying amount of the paint. The design of the independent power rotor ensures the uniformity and consistency of the coating. Compared with the traditional spraying technology, the PVDF solution can be sprayed more evenly and efficiently. This improvement reduces the waiting and adjustment time in the production process and further improves the production efficiency.

[0040] Moreover, the independent power rotor can be controlled individually and is not dependent on other components. It improves flexibility and optimizes energy transmission through independent drive, thereby ensuring uniform distribution of PVDF solution on the pretreated substrate and reducing the standard deviation of coating thickness on the same diaphragm surface.

[0041] See also Figure 1 As shown, the device further comprises a drying unit 4, which is used to cure the coating on the surface of the pre-treated substrate to form a finished diaphragm product, wherein the drying unit 4 is a hot air dryer or a vacuum drying oven.

[0042] A winding unit 5 is provided on one side of the drying unit 4. The winding unit 5 is used to wind up and store the finished diaphragm product. The winding unit 5 is also provided with a tension control system to ensure that the finished diaphragm product can be neatly and stably wound up.

[0043] It can be understood that conveying rollers are provided on the unwinding unit 1, the pretreatment unit 2, the spraying unit 3 and the drying unit 4 for conveying materials.

[0044] In this embodiment, the diaphragm substrate is stably released to the pretreatment unit 2 through the unwinding unit 1, the pretreatment unit 2 cleans and activates the diaphragm substrate, and transmits it to the spraying unit 3 for spraying paint, and then passes through the drying unit 4 to form a finished diaphragm product and is transmitted to the winding unit 5 for winding.

[0045] A method for producing a PVDF diaphragm using lithium ion spraying, comprising:

[0046] S1. The unwinding unit 1 releases the diaphragm substrate at a preset speed and adjusts the surface tension of the diaphragm substrate.

[0047] The preset speed can be adjusted according to the thickness of the diaphragm substrate. The 12μm diaphragm substrate is released at a speed of 5m / min, while the 16μm thick diaphragm substrate is released at a speed of 8m / min.

[0048] The tension control system in the unwinding unit 1 can ensure that the substrate maintains a constant tension during the unwinding process, avoiding wrinkles or stretching deformation, thereby improving the flatness of the diaphragm substrate and the uniformity of subsequent processing. For faster release speeds, thanks to further adjustment of the tension control system, the flatness and tension control of the diaphragm substrate can be effectively guaranteed even during high-speed unwinding.

[0049] S2, the pretreatment unit 2 performs surface cleaning and activation treatment on the diaphragm substrate to form a pretreated substrate.

[0050] Specifically, after the pretreatment unit 2 receives the substrate from the unwinding unit 1, it uses plasma treatment technology to treat the diaphragm substrate for 30 seconds to remove impurities on the surface of the diaphragm substrate, and also enhance the adhesion performance of the surface of the diaphragm substrate, providing good surface conditions for subsequent coating adhesion.

[0051] Furthermore, corona treatment technology can be used instead of plasma treatment to perform more in-depth surface cleaning and activation of the substrate. The corona treatment time is 60s. The extension of this treatment time helps to achieve a more thorough surface modification and provide stronger surface energy for the subsequent coating adhesion.

[0052] S3, spraying the PVDF solution on the pretreated substrate at a uniform speed through the spraying unit 3, so that a coating is formed on the surface of the pretreated substrate.

[0053] The PVDF solution sprayed from the nozzle on the support rod 31 adheres to the surface of the pretreated substrate, and the spraying rotor 32 in the nozzle adopts an independent power rotor, which rotates at a speed of 2000rpm to 3000rpm. A higher speed can further improve the uniformity and consistency of the coating.

[0054] The mass fraction of the PVDF solution is 10% to 15%, and the concentration of the PVDF solution is adjusted according to different needs.

[0055] It is understandable that the increase in the rotation speed of the spray rotor 32 and the increase in the concentration of the PVDF solution can make the coating more uniform and have stronger coverage, meeting the demand for higher energy density battery separators.

[0056] In addition, the improvement of coating uniformity and consistency can also lead to improvements in porosity and air permeability. Specifically, the more uniform and consistent the coating is, the fewer defects and uneven areas in the coating will be, the more uniform the distribution of pores in the coating will be, the higher the porosity will be, and the air permeability will be improved, thereby enhancing the overall performance of the separator material. This consistency can also promote the flow of examples, making the migration of ions in the battery smoother. This increase not only improves the transmission efficiency of lithium-ion batteries, but also helps to improve the overall performance of the battery.

[0057] S4, the drying unit 4 places the coating on the surface of the pre-treated substrate at a preset temperature and dries it for 5 minutes to solidify the coating to form a finished diaphragm.

[0058] In the present method, the drying unit 4 adopts a hot air dryer, which uses the flow of hot air to evaporate the water in the coating, thereby ensuring that the coating on the surface of the finished membrane is dried evenly.

[0059] The preset temperature is 80℃~100℃. The higher the temperature, the faster the coating cures. Extending the drying time from 5min to 8min can improve production efficiency while achieving an ideal curing state to enhance curing quality. The cured coating has good mechanical properties and chemical stability.

[0060] S5, the winding unit 5 winds up the finished diaphragm for storage.

[0061] In the present application, due to the improvement of coating uniformity and curing quality, the qualified rate of diaphragm products has also been effectively improved. The improvement of production efficiency and the increase in the qualified rate of diaphragm products have effectively reduced the production cost of unit products.

[0062] The diaphragm coating is made of PVDF material. Since PVDF has excellent chemical stability, thermal stability and mechanical strength, combined with the production process to modify the diaphragm material, it not only improves the quality of the diaphragm but also improves the safety of the battery.

[0063] The production device and method of the present invention are reasonably designed, easy to operate, simplify the operation process, reduce manual intervention, reduce the possibility of operating errors, make the diaphragm production smoother, and further improve the stability and repeatability of the production process.

[0064] In the present application, the production speed of the diaphragm, the thickness of the diaphragm substrate, the pretreatment method, the spraying parameters and the drying conditions can all be dynamically adjusted to meet the specific requirements for diaphragm performance in different application scenarios, thereby improving the flexibility and adaptability of the production line, and being able to be quickly adjusted according to different production needs to produce high-quality lithium-ion battery diaphragms that meet different performance indicators.

[0065] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of application of the present invention should still fall within the scope of the claims of the present invention.

Claims

1. A lithium ion spraying PVDF diaphragm production device, characterized in that: include: An unwinding unit (1), the unwinding unit (1) being used to release the diaphragm substrate; A pretreatment unit (2), the pretreatment unit (2) being used to clean and activate the substrate released by the unwinding unit (1), the diaphragm substrate after the cleaning and activation treatment being the pretreated substrate; A spraying unit (3), the spraying unit (3) is used to spray the coating material onto the pretreated substrate, the spraying unit (3) is provided with a spraying rotor (32), the spraying rotor (32) adopts an independent power rotor, and is used to adjust the spraying amount of the coating material; A drying unit (4), the drying unit (4) being used to cure the coating on the surface of the pretreated substrate to form a finished diaphragm; A winding unit (5), the winding unit (5) being used to wind up and store the finished diaphragm product; The unwinding unit (1), the pretreatment unit (2), the spraying unit (3) and the drying unit (4) are all provided with conveying rollers for conveying materials; The unwinding unit (1) stably releases the diaphragm substrate to the pretreatment unit (2); the pretreatment unit (2) cleans and activates the diaphragm substrate and then transmits it to the spraying unit (3) for spraying; the diaphragm substrate is then made into a finished product by the drying unit (4) and then transmitted to the winding unit (5) for winding.

2. A lithium ion spraying PVDF diaphragm production device according to claim 1, characterized in that: The pretreatment unit (2) comprises a cleaning mechanism (21), wherein the cleaning mechanism (21) is a cleaning brush for removing pollutants on the surface of the membrane substrate.

3. A lithium ion spraying PVDF diaphragm production device according to claim 2, characterized in that: The pretreatment unit (2) further comprises a plasma treatment chamber (26), wherein the plasma treatment chamber (26) is connected to the iso-electrode (23), and a plasma generator (24) is arranged on the top of the iso-electrode (23).

4. A lithium ion spraying PVDF diaphragm production device according to claim 3, characterized in that: One side of the iso-electrode (23) is connected to a gas supply mechanism (22), and the other side is connected to an exhaust mechanism (25).

5. A lithium ion spraying PVDF diaphragm production device according to claim 1, characterized in that: The spraying unit (3) is provided with a support rod (31), a plurality of nozzles are provided on the support rod (31), and a spraying rotor (32) is provided in the nozzle.

6. A lithium ion spraying PVDF diaphragm production device according to claim 1, characterized in that: The unwinding unit (1) and the rewinding unit (5) are both provided with a tension control system for tensioning the material.

7. A method for producing a lithium ion sprayed PVDF diaphragm using the device according to any one of claims 1 to 6, characterized in that: include: S1, the unwinding unit (1) releases the diaphragm substrate at a preset speed and adjusts the surface tension of the diaphragm substrate; S2, the pretreatment unit (2) performs surface cleaning and activation treatment on the diaphragm substrate to form a pretreated substrate; S3, spraying the PVDF solution on the pretreated substrate at a uniform speed through the spraying unit (3), so that a coating is formed on the surface of the pretreated substrate; S4, a drying unit (4) dries the coating on the surface of the pre-treated substrate at a preset temperature to solidify the coating to form a finished diaphragm; S5, the winding unit (5) winds up the finished diaphragm for storage.

8. The method according to claim 7, characterized in that In step S3, the mass fraction of the PVDF solution is 10% to 15%.

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