A high vacuum tunnel furnace for removing water from lithium batteries using a liquid bath heating method

Abstract

The present invention discloses a high vacuum tunnel furnace for dehydrating lithium batteries using a liquid bath method for heating, comprising a tunnel furnace shell, a vacuum cavity and a drying cavity arranged in the tunnel furnace shell; the vacuum cavity is connected to a vacuum pump, a first sealing door and a second sealing door are arranged at both ends of the vacuum cavity, the first sealing door is connected to the outside of the tunnel furnace shell, the second sealing door is connected to the drying cavity, an exchanger layer plate is arranged in the vacuum cavity, a liquid flow channel is built in the exchanger layer plate, and the liquid flow channel is connected to a heat exchanger and a liquid storage tank; the drying cavity is connected to a drying device, a circulation device is arranged in the drying cavity, and the circulation device takes out a tray with a battery cell from the vacuum cavity and flows it out of the tunnel furnace shell. The beneficial effects of the present invention are: the high vacuum tunnel furnace for dehydrating lithium batteries using a liquid bath method for heating can simultaneously perform vacuuming and heating in the vacuum cavity, reducing the energy consumption and occupied space of vacuum heating and drying.

Description

Technical Field

[0001] The invention relates to the technical field of battery vacuum dehydration and drying, in particular to a lithium battery dehydration high vacuum tunnel furnace which adopts a liquid bath method for heating. Background Art

[0002] With the rapid development of new energy vehicles, the new energy industry has increasingly stringent requirements on the quality of lithium batteries. Lithium battery manufacturers need to constantly look for production methods with better quality, higher efficiency and lower costs to improve the level of lithium battery production.

[0003] In the production process of lithium batteries, the dehydration and drying process of lithium batteries is a key step that affects the quality of lithium batteries. If the lithium battery is not fully dried, the electrolyte in the battery will react with water to generate trace amounts of harmful gases, which will have an adverse effect on the environment of the injection room. It will also affect the quality of the electrolyte itself, resulting in poor battery performance and rust on the battery rivets. For this reason, lithium batteries need to be dehydrated and dried to avoid the impact of moisture on lithium batteries and the injection environment.

[0004] Existing drying methods include traditional air convection heating method, where the heated air heats the battery and then evacuates it. This method has high energy consumption and long heating time; contact electric heating method, which can quickly heat the battery, but the thermal inertia of electric heating is large, and there is a possibility of overheating, which can easily cause damage to the battery, and there is also the problem of high equipment cost; high vacuum tunnel furnace for dehydration drying, which uses air convection heating and has three cavities, and its disadvantages are high equipment energy consumption, large size and high maintenance cost. To this end, those skilled in the art need to improve the shortcomings of existing drying technology. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a high vacuum tunnel furnace for dehydrating lithium batteries by liquid bath heating in view of the deficiencies of the above-mentioned prior art.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a high vacuum tunnel furnace for dehydrating lithium batteries using a liquid bath method for heating, comprising a tunnel furnace shell, a vacuum cavity and a drying cavity are arranged in the tunnel furnace shell; the vacuum cavity is connected to a vacuum pump, and a first sealing door and a second sealing door are arranged at both ends of the vacuum cavity, the first sealing door is connected to the outside of the tunnel furnace shell, and the second sealing door is connected to the drying cavity, an exchanger layer plate is arranged in the vacuum cavity, and a liquid flow channel is built in the exchanger layer plate, and the liquid flow channel is connected to a heat exchanger and a liquid storage tank; the drying cavity is connected to a drying device, and a circulation device is arranged in the drying cavity, and the circulation device takes out a tray with a battery cell from the vacuum cavity and flows it out of the tunnel furnace shell.

[0007] In the above technical solution, the transfer device includes a manipulator and a belt conveyor. The manipulator enters the vacuum chamber through the second sealed door, takes out the tray with the battery cells and places it on the belt conveyor. The belt conveyor transfers the tray out of the tunnel furnace shell.

[0008] In the above technical solution, the heat exchanger is provided with three flow channel interfaces, the liquid storage tank is provided with a liquid outlet and a liquid return port, and the exchanger layer plate is provided with a flow channel inlet and a flow channel outlet; the liquid outlet is connected to the flow channel inlet and is provided with a liquid inlet valve, the liquid return port is connected to the flow channel outlet and is provided with a liquid drain valve, the three flow channel interfaces are correspondingly connected to the liquid outlet, the flow channel inlet, and the liquid return port and the flow channel outlet, and the flow channel interfaces are all provided with heat exchange valves.

[0009] In the above technical solution, the first sealing door is a rotary sealing door or a translational sealing door, and the second sealing door is a translational sealing door.

[0010] In the above technical solution, water or oil is stored in the liquid storage tank.

[0011] In the above technical solution, the exchanger layer plates are made of stainless steel or aluminum alloy.

[0012] The beneficial effects of the present invention are as follows: the high vacuum tunnel furnace for dehydrating lithium batteries using the liquid bath method for heating can simultaneously perform vacuuming and heating in a vacuum cavity, thereby reducing the energy consumption and occupied space of vacuum heating drying. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of an embodiment of the present invention.

[0014] Figure 2 It is a schematic diagram of the connection structure of the heat exchanger part of one embodiment of the present invention.

[0015] 1. Tunnel furnace shell; 11. First sealing door; 12. Second sealing door; 2. Vacuum chamber; 21. Exchanger layer plate; 211. Flow channel inlet; 212. Flow channel outlet; 22. Tray; 23. Battery cell; 3. Vacuum pump; 4. Heat exchanger; 41. Heat exchange valve; 42. Liquid inlet valve; 43. Liquid drain valve; 44. Liquid storage tank; 441. Liquid outlet; 442. Liquid return port; 5. Drying chamber; 6. Manipulator; 7. Drying device; 8. Belt conveyor; 9. Inner chamber of liquid injection machine. DETAILED DESCRIPTION

[0016] The present invention will be further described in detail below in conjunction with the accompanying drawings.

[0017] like Figure 1The figure shows an embodiment of the present invention, a high vacuum tunnel furnace for removing water from lithium batteries using a liquid bath method for heating, comprising a tunnel furnace shell 1, in which a vacuum cavity 2 and a drying cavity 5 are arranged. The vacuum cavity 2 is used for vacuum heating and drying of lithium batteries, and the vacuum cavity 2 is connected to a vacuum pump 3, which is responsible for evacuating the vacuum cavity 2. A first sealing door 11 and a second sealing door 12 are provided at both ends of the vacuum cavity 2, and the first sealing door 11 is connected to the outside of the tunnel furnace shell 1. The battery cell 23 to be dried is placed on a tray 22, and the first sealing door 11 is opened, and the tray 22 enters the vacuum cavity 2 from the first sealing door 11. The first sealing door 11 and the second sealing door 12 are closed, so that the vacuum cavity 2 forms a sealed space. An exchanger plate 21 is provided in the vacuum chamber 2, and a tray 22 with batteries is placed in the exchanger plate 21. The exchanger plate 21 is provided with a liquid flow channel (not shown in the figure), and the liquid flow channel is distributed inside the exchanger plate 21. When the liquid flows in the liquid flow channel, heat is transferred to the exchanger plate 21, and the heat of the exchanger plate 21 is then transferred to the tray 22 and the battery cell 23 in the tray 22 for heating. Preferably, the exchanger plate 21 is made of stainless steel or aluminum alloy material, which has good thermal conductivity and strength, can ensure heat exchange efficiency and bear the weight of the tray 22.

[0018] Combination Figure 2 As shown, the exchanger layer plate 21 is connected to the heat exchanger 4 and the liquid storage tank 44 outside the vacuum chamber 2 through a pipeline. The exchanger layer plate 21 is provided with a flow channel inlet 221 and a flow channel outlet 212. The heat exchange liquid enters the exchanger layer plate 21 from the flow channel inlet 221 and then flows out from the flow channel outlet 212. The heat exchanger 4 is used to adjust the temperature of the liquid. The heat exchanger 4 is provided with three flow channel interfaces; the liquid storage tank 44 is provided with a liquid outlet 441 and a liquid return port 442. The liquid storage tank 44 stores the liquid for heat exchange, which is generally water or oil. Specifically, the liquid outlet 441 of the liquid storage tank 44 is connected to the flow channel inlet 221 of the exchanger layer plate 21, and a liquid inlet valve 42 is provided between the liquid outlet 441 and the flow channel inlet 221 to control whether the liquid storage tank 44 and the exchanger layer plate 21 are directly connected to inlet liquid, and the liquid return port 442 of the liquid storage tank 44 is connected to the flow channel outlet 212 of the exchanger layer plate 21, and a liquid discharge valve 43 is provided between the liquid return port 442 and the flow channel outlet 212 to control whether the liquid flows back into the liquid storage tank 44. The three flow channel interfaces of the heat exchanger 4 correspond to the liquid outlet 441 of the liquid storage tank 44, the flow channel inlet 221 of the exchanger layer plate 21, and the pipelines connected between the liquid return port 442 and the flow channel outlet 212, and heat exchange valves 41 are provided at the three flow channel interfaces.

[0019] The heat exchanger 4 and the liquid storage tank 44 realize the heating and cooling functions in the tunnel furnace. When heating starts, the liquid inlet valve 42 between the liquid storage tank 44 and the exchanger layer plate 21 is closed, and the two heat exchange valves 41 of the heat exchanger 4 connecting the liquid outlet 441 of the liquid storage tank 44 and the flow channel inlet 221 of the exchanger layer plate 21 are opened, and the liquid is heated by the heat exchanger 4, and the heated liquid enters the exchanger layer plate 21 to heat the tray 22 and the battery cell 23. After the liquid flows out of the exchanger layer plate 21, the drain valve 43 at the liquid return port 442 is closed, and the heat exchange valve 41 connected to the heat exchanger 4 between the liquid return port 442 and the flow channel outlet 212 is opened, and the liquid flows back into the heat exchanger 4 for heating and then flows into the exchanger layer plate 21. After the liquid between the heat exchanger 4 and the exchanger layer plate 21 is sufficient, the heat exchange valve 41 between the heat exchanger 4 and the liquid storage tank 44 is closed. When the exchanger plate needs to be cooled, the liquid inlet valve 42 and the liquid outlet valve 43 are opened, the three heat exchange valves 41 are closed, and the liquid with a lower temperature in the liquid storage tank 44 enters the exchanger plate 21 for cooling.

[0020] After the battery cell 23 is vacuum-heated and dried in the vacuum chamber 2, the vacuum chamber 2 is depressurized, and the tray 22 with the battery is removed from the second sealed door 12. The other end of the second sealed door 12 is connected to the drying chamber 5, and the drying chamber 5 is connected to a drying device 7. The drying device 7 ensures that the interior of the drying chamber 5 is dry to prevent the battery from reabsorbing moisture during circulation. A circulation device is provided in the drying chamber 5, and the circulation device includes a manipulator 6 and a belt conveyor 8. After the second sealed door 12 is opened, the manipulator 6 enters the vacuum chamber 2 to grab the tray 22 and put the tray 22 on the belt conveyor 8. A material outlet is opened on one side of the drying chamber 5 together with the tunnel furnace shell 1. The material outlet is connected to the internal cavity 9 of the liquid injection machine. The belt conveyor 8 extends from the material outlet to the internal cavity 9 of the liquid injection machine. The belt conveyor 8 transfers the tray 22 with the battery to the internal cavity 9 of the liquid injection machine to complete the vacuum heating and drying of the battery cell 23.

[0021] Furthermore, the first sealed door 11 is connected to the external space of the tunnel furnace shell 1, and can be opened and closed by a rotating sealed door or a sliding sealed door; the second sealed door 12 is tightly attached between the vacuum chamber 2 and the drying chamber 5, and can be opened and closed by a sliding sealed door to save space for moving the door.

[0022] The above embodiments are only for illustration rather than limitation of the present invention, so all equivalent changes or modifications made according to the method described in the scope of the present patent application are included in the scope of the present patent application.

Claims

1. A high vacuum tunnel furnace for removing water from lithium batteries using a liquid bath heating method, characterized in that: It comprises a tunnel furnace shell, in which a vacuum cavity and a drying cavity are arranged; the vacuum cavity is connected to a vacuum pump, and a first sealing door and a second sealing door are arranged at both ends of the vacuum cavity, the first sealing door is connected to the outside of the tunnel furnace shell, and the second sealing door is connected to the drying cavity, and an exchanger layer plate is arranged in the vacuum cavity, and a liquid flow channel is built in the exchanger layer plate, and the liquid flow channel is connected to a heat exchanger and a liquid storage tank; the drying cavity is connected to a drying device, and a circulation device is arranged in the drying cavity, and the circulation device takes out a tray with a battery cell from the vacuum cavity and circulates it out of the tunnel furnace shell; The transfer device includes a manipulator and a belt conveyor. The manipulator enters the vacuum chamber through the second sealing door to take out the tray with the battery cells and puts it on the belt conveyor. The belt conveyor transfers the tray out of the tunnel furnace shell. A material outlet is opened on one side of the drying chamber together with the tunnel furnace shell, and the material outlet is connected to the inner cavity of the liquid injection machine. A belt conveyor extends from the material outlet to the inner cavity of the liquid injection machine, and the belt conveyor transfers the tray with batteries to the inner cavity of the liquid injection machine; The heat exchanger is provided with three flow channel interfaces, the liquid storage tank is provided with a liquid outlet and a liquid return port, the exchanger layer plate is provided with a flow channel inlet and a flow channel outlet; the liquid outlet is connected to the flow channel inlet and is provided with a liquid inlet valve, the liquid return port is connected to the flow channel outlet and is provided with a liquid discharge valve, the three flow channel interfaces are correspondingly connected to the liquid outlet, the flow channel inlet, and the liquid return port and the flow channel outlet, and the flow channel interfaces are all provided with heat exchange valves; The first sealing door is a rotary sealing door or a translational sealing door, and the second sealing door is a translational sealing door.

2. The high vacuum tunnel furnace for removing water from lithium batteries using a liquid bath heating method according to claim 1, characterized in that: Water or oil is stored in the liquid storage tank.

3. The high vacuum tunnel furnace for removing water from lithium batteries using a liquid bath heating method according to claim 1, characterized in that: The exchanger layer plates are made of stainless steel or aluminum alloy.

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