A lithium battery vacuum drying device

Abstract

The utility model discloses a lithium battery vacuum drying device, including drying room, be located in the vacuum oven of drying room, the vacuum oven has the cavity for placing battery, the vacuum oven still is equipped with baffle valve, the baffle valve has gas import and gas export, wherein, the gas import is linked together with drying room, and the gas export is linked together with the cavity. The utility model has realized nitrogen -free drying. By integrating the vacuum oven in the closed drying room of dew point <=-40 DEG C, and utilizing its ambient gas as the medium of heat transfer and moisture displacement, the dependence on nitrogen in the traditional process is abandoned. This not only directly saves the purchase and maintenance cost of expensive nitrogen generator, gas tank and supporting system, but also greatly reduces the energy consumption in the production process, and provides a new path of energy saving and cost reduction for lithium battery manufacturing.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery manufacturing technology, and in particular to a lithium battery vacuum drying device. Background Technology

[0002] Moisture control is a critical quality control step in lithium battery production, directly affecting battery life, safety, and electrochemical performance. Vacuum drying, as a core process in lithium battery manufacturing, directly determines the moisture content of the battery product. Currently, the industry commonly uses high-purity nitrogen gas to fill a vacuum oven for drying. Nitrogen gas plays two main roles: first, as a heat transfer medium during the preheating stage, promoting uniform and rapid heating of the battery; second, as a displacement gas during the vacuum drying stage, carrying away residual moisture deep within the battery electrodes. However, this method requires a continuous consumption of large amounts of nitrogen, relying on nitrogen generation equipment and supporting storage and transportation systems. This not only results in high equipment investment costs but also significant energy consumption, increasing the overall cost of lithium battery production.

[0003] Furthermore, to meet the low-humidity environmental requirements of lithium battery production, vacuum ovens are typically placed in low-dew-point drying chambers. These chambers often maintain a dew point temperature of ≤-40℃, and their atmospheric moisture content is extremely low, comparable to nitrogen, yet this moisture has not been effectively utilized. Therefore, if the gas within these drying chambers could be directly used as a drying medium to replace nitrogen for preheating and moisture replacement, it would effectively avoid resource waste, reduce dependence on nitrogen, and decrease equipment investment and operating costs. This would be of great significance for promoting energy conservation and emission reduction in the lithium battery manufacturing process. Utility Model Content

[0004] The purpose of this invention is to provide a lithium battery vacuum drying device that uses low dew point gas in the drying chamber to replace nitrogen as the drying medium. This ensures the drying quality of the lithium battery while completely eliminating the need for nitrogen generation equipment and nitrogen consumption, thus significantly reducing equipment investment and production costs.

[0005] To achieve the above objectives, this utility model provides the following technical solution: This utility model discloses a lithium battery vacuum drying device, including a drying chamber and a vacuum oven disposed in the drying chamber; the vacuum oven has a cavity for placing batteries; the vacuum oven is also provided with a baffle valve, the baffle valve has a gas inlet and a gas outlet, wherein the gas inlet is connected to the drying chamber and the gas outlet is connected to the cavity.

[0006] A further embodiment: The baffle valve further includes a cylinder, a piston rod movably connected to the cylinder, and a power unit that drives the piston rod to perform piston movement. The other end of the piston rod passes through the cylinder and is connected to a pressure plate. An elastic element is provided between the pressure plate and the cylinder. The piston rod is coaxially arranged with the gas outlet.

[0007] A further embodiment: The power unit includes a compressed air inlet connected to the cylinder and a solenoid valve for controlling the opening and closing of the compressed air inlet.

[0008] A further solution: the pressure-bearing surface of the pressure plate is provided with a sealing ring.

[0009] A further solution: The cavity is equipped with a heating plate for heating the battery.

[0010] A further solution: The vacuum oven is equipped with a sealing door for opening and closing the cavity.

[0011] A further embodiment: the cavity is provided with a tray for supporting the battery; the tray is located above the heating plate.

[0012] A further option: The drying room is a sealed space that maintains a dew point temperature of ≤-40℃.

[0013] Compared with the prior art, the beneficial effects of this utility model are: This invention achieves nitrogen-free drying. By integrating a vacuum oven into a sealed drying chamber with a dew point ≤ -40℃, and utilizing the ambient gas as the medium for heat transfer and moisture replacement, the reliance on nitrogen in traditional processes is eliminated. This not only directly saves the purchase and maintenance costs of expensive nitrogen generators, gas storage tanks, and supporting systems, but also significantly reduces energy consumption in the production process, providing a new energy-saving and cost-reducing path for lithium battery manufacturing.

[0014] This device achieves timed automatic filling and vacuuming of drying gas through an optimized baffle valve structure and vacuum circulation process. This "filling-vacuuming" circulation mechanism can effectively agitate and remove moisture deep within the battery electrodes. Its water removal efficiency and drying quality are comparable to traditional nitrogen processes, meeting the stringent requirements of lithium batteries for water content, while avoiding the risk of oxidation during the drying process. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the planar structure of this utility model; Figure 2 This is an installation diagram of the tray, heating plate, and battery in this utility model; Figure 3 This is a three-dimensional structural diagram of the present invention; Figure 4 This is a schematic diagram showing the state of the baffle valve supplying gas to the vacuum oven in this utility model. Figure 5 This is a schematic diagram showing the state when the baffle valve in this utility model cuts off the gas supply to the vacuum oven; In the diagram: 1-Drying chamber, 2-Vacuum oven, 21-Cavity, 22-Sealed door, 23-Vacuum port, 3-Baffle valve, 31-Gas inlet, 32-Gas outlet, 33-Cylinder, 34-Piston rod, 35-Power unit, 351-Compressed air inlet, 352-Solenoid valve, 36-Elastic element, 37-Sealing ring, 38-Pressure plate, 4-Heating plate, 5-Tray, 6-Battery. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] In the description of this utility model, it should be noted that the terms "upper", "lower", "left", "right", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the utility model product is usually placed in during use. 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 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 utility model.

[0018] Please see Figure 1-5 A lithium battery vacuum drying device includes a drying chamber 1 and a vacuum oven 2 disposed within the drying chamber 1. The vacuum oven 2 has a cavity 21 for placing batteries. The vacuum oven 2 is also equipped with a baffle valve 3, which has a gas inlet 31 and a gas outlet 32. The gas inlet 31 is connected to the drying chamber 1, and the gas outlet 32 ​​is connected to the cavity 21. By placing the vacuum oven 2 inside the low dew point drying chamber 1 and installing the baffle valve 3 connecting the drying chamber 1 and the cavity of the vacuum oven 2, extremely dry gas in the drying chamber 1 can be directly introduced as a drying medium. This eliminates the need for nitrogen generation, storage, and transportation equipment in traditional nitrogen systems, significantly reducing equipment investment costs and operating energy consumption, and achieving an energy-saving and environmentally friendly production method.

[0019] Furthermore, the baffle valve 3 also includes a cylinder 33, a piston rod 34 movably connected to the cylinder 33, a power unit 35 driving the piston rod 34 to perform piston movement, a pressure plate 38 connected to the other end of the piston rod 34, and an elastic element 36 disposed between the pressure plate 38 and the cylinder 33; the piston rod 34 is coaxially arranged with the gas outlet 32. The baffle valve structure driven by the cylinder 33, piston rod 34, and elastic element 36 enables rapid, reliable, and automated opening and closing of the valve port; the elastic element 36 (such as a spring) ensures that the pressure plate 38 automatically closes under its preload in the event of a power outage or gas source failure, achieving fault safety protection and ensuring the sealing of the vacuum oven cavity and production safety.

[0020] Furthermore, the power unit 35 includes a compressed air inlet 351 connected to the cylinder 33 and a solenoid valve 352 for controlling the opening and closing of the compressed air inlet 351. By controlling the compressed air power source through the solenoid valve 352, the opening and closing state of the baffle valve 3 is controlled.

[0021] Furthermore, the pressure-bearing surface of the pressure plate 38 is provided with a sealing ring 37. When the baffle valve 3 is closed, the pressure plate 38 can compress the sealing ring 37 to produce deformation, thereby achieving a combination of metal hard seal and elastic soft seal, which greatly improves the sealing performance of the valve port in a high vacuum environment, effectively prevents gas leakage, and maintains a stable vacuum level in the cavity 21.

[0022] Please continue reading. Figure 4 and Figure 5 When the solenoid valve 352 is energized and opened, compressed air instantly enters the cylinder 33, pushing the piston rod 34 to retract (moving to the left in the figure). The baffle valve 3 opens, connecting the gas inlet 31 and the gas outlet 32, and the dry gas fills the cavity 21. When the solenoid valve 352 is de-energized and closed, the compressed air is blocked and cannot reach the cylinder 33. The piston rod 34 gradually extends under the action of the elastic element 36 (moving to the right in the figure), and the pressure plate 38 blocks the gas outlet 32, preventing the dry gas from entering the cavity 21.

[0023] Furthermore, the cavity 21 is equipped with a heating plate 4 for heating the battery. This heating plate 4 can directly and uniformly heat the battery 6 through contact, with high heat conduction efficiency, ensuring that the battery can quickly and uniformly rise to the temperature required by the process, providing the necessary temperature conditions for subsequent vacuum drying and dehydration, and improving drying efficiency.

[0024] Furthermore, the vacuum oven 2 is equipped with a sealing door 22 for opening and closing the cavity 21. The sealing door 22 ensures that the cavity of the vacuum oven 2 is completely isolated from the external environment during the drying process. On the one hand, it maintains the vacuum environment inside the cavity 21, and on the other hand, it prevents the entry of high-humidity air from the outside, avoiding secondary moisture absorption by the battery 6 during the drying process and ensuring the drying quality.

[0025] Furthermore, the cavity 21 is provided with a tray 5 for supporting the battery; the tray 5 is located above the heating plate 4. The tray 5 is used to hold the battery 6, keeping it at a certain distance from the heating plate 4 to avoid local overheating of the battery; at the same time, the tray 5 ensures that multiple batteries 6 can be placed neatly and stably, improving the space utilization of the cavity 21 and the uniformity of heating.

[0026] Furthermore, the drying chamber 1 is a sealed space that maintains a dew point temperature of ≤-40℃. This dew point temperature ensures that the moisture content of the gas inside (approximately 126.8 PPM) is far below the battery process requirements (≤400 PPM). This gas will neither cause battery oxidation nor lead to battery moisture absorption, thus fundamentally guaranteeing the feasibility and reliability of using the drying chamber gas to replace nitrogen from an environmental perspective.

[0027] In operation, the present invention first places a tray 5 filled with lithium batteries into the cavity 21 of the vacuum oven 2 and closes the sealing door 22. Then, the gas inside the vacuum oven 2 is evacuated from atmospheric pressure to 50 Pa via vacuum port 23 using a vacuum pump. After completion, the baffle valve 3 is opened, allowing dry gas from the drying chamber 1 to enter through gas inlet 31 and fill the cavity 21 through gas outlet 32 ​​until atmospheric pressure is restored. Next, the heating plate 4 is turned on to preheat the batteries for 2 to 4 hours within the range of 80 to 120°C. After preheating, the vacuum is evacuated again to 50 Pa, and the drying chamber 1 is filled with gas. The vacuum drying stage then begins, maintaining the temperature and pressure at a vacuum environment of 50 to 200 Pa for 4 to 8 hours. During this period, every hour, the solenoid valve 352 is energized, and compressed air enters the cylinder 33 through the compressed air inlet 351, pushing the piston rod 34 to retract, opening the baffle valve 3 to fill the drying chamber 1 with gas to displace moisture, and then the vacuum is evacuated again to remove the moisture. After the entire drying process is completed, the drying chamber 1 is filled with gas to atmospheric pressure to end the cycle.

[0028] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0029] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A lithium battery vacuum drying device, characterized in that, The equipment includes a drying chamber (1) and a vacuum oven (2) located in the drying chamber (1); the vacuum oven (2) has a cavity (21) for placing batteries; the vacuum oven (2) is also provided with a baffle valve (3), the baffle valve (3) having a gas inlet (31) and a gas outlet (32), wherein the gas inlet (31) is connected to the drying chamber (1) and the gas outlet (32) is connected to the cavity (21).

2. The lithium battery vacuum drying apparatus according to claim 1, characterized in that, The baffle valve (3) also includes a cylinder (33), a piston rod (34) movably connected to the cylinder (33), and a power unit (35) that drives the piston rod (34) to perform piston movement. The other end of the piston rod (34) passes through the cylinder (33) and is connected to a pressure plate (38). An elastic element (36) is provided between the pressure plate (38) and the cylinder (33). The piston rod (34) is coaxially arranged with the gas outlet (32).

3. The lithium battery vacuum drying apparatus according to claim 2, characterized in that, The power unit (35) includes a compressed air inlet (351) connected to the cylinder (33) and a solenoid valve (352) for controlling the opening and closing of the compressed air inlet (351).

4. The lithium battery vacuum drying apparatus according to claim 2, characterized in that, The pressure plate (38) is provided with a sealing ring (37) on its pressure-bearing surface.

5. The lithium battery vacuum drying apparatus according to claim 1, characterized in that, The cavity (21) is provided with a heating plate (4) for heating the battery.

6. The lithium battery vacuum drying apparatus according to claim 1, characterized in that, The vacuum oven (2) is provided with a sealing door (22) for opening and closing the cavity (21).

7. The lithium battery vacuum drying apparatus according to claim 5, characterized in that, The cavity (21) is provided with a tray (5) for carrying the battery; the tray (5) is located above the heating plate (4).

8. The lithium battery vacuum drying apparatus according to claim 1, characterized in that, The drying room (1) is a sealed space that maintains a dew point temperature of ≤-40℃.

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