Vacuum drying device for pole piece strip

Abstract

The utility model provides a pole piece strip vacuum drying device capable of conveniently removing moisture in the device, and relates to the related technical field of lithium battery manufacturing. The pole piece strip vacuum drying device comprises a drying device, a cooling device, a baking chamber and a cooling chamber, the baking chamber and the cooling chamber are both arranged in a sealed mode, the cooling chamber is provided with a strip channel with one end communicated with the baking chamber, the baking chamber and the cooling chamber are both communicated with vacuumizing pipes, and the vacuumizing pipes are communicated with the baking chamber. The drying device is arranged in the baking chamber, the cooling device is arranged in the cooling chamber, condensation pipes are arranged in the baking chamber and the cooling chamber, the two ends of each condensation pipe extend out of the chamber, and the condensation pipes are used for allowing refrigerants to pass through. The pole piece strip drying device can improve the drying quality of pole piece strips.

Description

Technical Field

[0001] The utility model relates to the technical field related to lithium battery manufacturing, in particular to a vacuum drying device for pole piece strips. Background Art

[0002] Moisture has a great impact on the performance of lithium-ion batteries. At present, the battery manufacturing level can tolerate 200-400ppm of water content. In order to strictly control the moisture content of lithium-ion batteries, it is necessary to dry the battery pole strips, battery cells, etc.

[0003] In order to improve the drying effect of battery pole pieces, vacuum drying is generally used for current battery pole pieces. For example, the Chinese patent with publication number CN216644738U discloses a pole piece strip drying device, including a chassis and an unwinding mechanism, a drying mechanism, a cooling mechanism and a winding mechanism sequentially built into the chassis; the inside of the chassis is provided with a feeding chamber, a drying chamber, a cooling chamber and a receiving chamber, and the feeding chamber, the drying chamber, the cooling chamber and the receiving chamber are all connected with a vacuum exhaust pipe; the unwinding mechanism is built into the feeding chamber, and is used to release the rolled pole piece strip; the drying mechanism is built into the drying chamber, and the drying mechanism includes a plurality of heating rollers arranged at intervals, and the pole piece strip is sequentially wound around each of the heating rollers to heat and dry the pole piece strip; the cooling mechanism is built into the cooling chamber, and the cooling mechanism includes a plurality of cooling rollers arranged at intervals, and the pole piece strip is sequentially wound around each of the cooling rollers to cool the pole piece strip after drying; the winding mechanism is built into the receiving chamber, and is used to recycle the pole piece strip after drying and cooling into a roll.

[0004] During the vacuum drying process of the battery pole piece, as the water vapor in the pole piece strip is continuously dried out, the water vapor content in the device will increase. The higher the water vapor content in the device, the more difficult it is to dry out the water vapor, and it is easy to be reabsorbed during cooling, and the drying effect of the strip is also worse. However, the vacuum degree needs to be strictly controlled during the drying process of the battery pole piece. The existing pole piece strip drying device can only simply evacuate the vacuum through the vacuum exhaust pipe when the vacuum degree does not meet the requirements to extract a small amount of water vapor, and the device is inconvenient to remove water. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a vacuum drying device for pole piece strips which can conveniently remove moisture in the device.

[0006] The utility model adopts the following technical solution to solve the technical problem: a vacuum drying device for electrode strips, comprising a drying device, a cooling device, a baking chamber and a cooling chamber, wherein the baking chamber and the cooling chamber are both sealed, the cooling chamber is provided with a strip channel whose one end is connected to the baking chamber, the baking chamber and the cooling chamber are both connected with a vacuum pipe, the drying device is arranged in the baking chamber, the cooling device is arranged in the cooling chamber, and the baking chamber and the cooling chamber are both provided with condensing pipes for passing refrigerant, the two ends of which extend outside the chamber.

[0007] Furthermore, the drying device comprises at least two heating rollers arranged at intervals, the pole piece strip is wound around the heating rollers in sequence, and one of the heating rollers cooperates with one side of the pole piece strip, and the other cooperates with the other side of the pole piece strip.

[0008] Furthermore, the heating roller is an electromagnetic heating roller.

[0009] Furthermore, the drying device also includes a preheating device arranged in front of the heating roller for preheating the pole piece strip, and the preheating device is an infrared heating device.

[0010] Furthermore, the cooling device includes at least two cooling rollers arranged at intervals, each of which is provided with a cooling channel for passing a cooling medium, and the pole piece strips are sequentially wound around the cooling rollers, and one of them cooperates with one side of the pole piece strip, and the other cooperates with the other side of the pole piece strip.

[0011] Furthermore, the condenser tube in the baking chamber is arranged around the heating roller.

[0012] Furthermore, the condenser tube in the cooling chamber is arranged around the cooling roller.

[0013] Furthermore, the baking chamber and the cooling chamber are respectively connected to an inflation pipe, an on-off control valve is provided on the inflation pipe, and the inflation pipe is connected to a nitrogen gas source.

[0014] Furthermore, humidity sensors are provided in both the baking chamber and the cooling chamber.

[0015] Furthermore, the refrigerant temperature in the condenser is -50°C.

[0016] The beneficial effects of the utility model are:

[0017] The vacuum drying device for pole piece strips of the utility model is provided with condensing tubes for passing refrigerant, both ends of which extend outside the cavity, in the baking chamber and the cooling chamber. Refrigerant below -50°C can be passed into the condensing tubes during drying, so that the surface temperature of the condensing tubes is below -50°C. Once the water vapor in the baking chamber and the cooling chamber contacts the condensing tubes, it will condense and accumulate ice adsorbed on the condensing tubes, thereby removing the water vapor in the baking chamber and the cooling chamber, reducing the water vapor content in the baking chamber and the cooling chamber, solving the problem of inconvenient water removal in the device, and improving the drying quality of the pole piece strips.

[0018] The vacuum drying device for the pole piece strip of the utility model is provided with a preheating device. The heating roller adopts an electromagnetic heating roller. The preheating device is an infrared heating device, which can preheat the pole piece first and then heat it in the heating roller. The electromagnetic heating roller can control the temperature within ±1°C and can quickly respond to the temperature rise, so that the temperature of the pole piece strip can be controlled more accurately.

[0019] The baking chamber and cooling chamber of the utility model are also respectively connected with an inflation pipe, on which an on-off control valve is provided. The inflation pipe is connected to a nitrogen gas source to form a nitrogen replenishing system, which can inject nitrogen to displace part of the water vapor in the baking chamber and the cooling chamber that is not condensed and adsorbed by the condenser. The system can be used separately from the condenser or used together with the condenser, and can be flexibly applied according to actual production data, effectively solving the technical problem of moisture baked out of the vacuum chamber re-entering the electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural schematic diagram of the utility model;

[0021] Figure 2 It is a structural schematic diagram of the utility model;

[0022] As shown in the figure: baking chamber 1, cooling chamber 2, vacuum tube 3, electrode strip 4, drying device 5, cooling device 6, condenser 7, charging tube 8, nitrogen gas source 9, strip channel 21, preheating device 51, heating roller 52, cooling roller 61, on-off control valve 81. DETAILED DESCRIPTION

[0023] The utility model is further described below in conjunction with the accompanying drawings and embodiments.

[0024] like Figure 1 , Figure 2As shown, the pole piece strip vacuum drying device of the utility model is used for drying the pole piece strip 4, and includes a drying device 5, a cooling device 6, a baking chamber 1 and a cooling chamber 2. The baking chamber 1 and the cooling chamber 2 are both sealed, and the cooling chamber 2 is provided with a strip channel 21 whose one end is connected to the baking chamber 1, and the strip channel 21 is correspondingly arranged according to the thickness and width of the pole piece strip 4. The baking chamber 1 and the cooling chamber 2 are both connected with a vacuum pipe 3, the drying device 5 is arranged in the baking chamber 1, and the cooling device 6 is arranged in the cooling chamber 2. The baking chamber 1 and the cooling chamber 2 are both provided with a condenser 7 for passing a refrigerant, and the two ends extend outside the chamber. The condenser 7 can be an iron pipe, a copper pipe, etc. In order to facilitate heat transfer, the condenser 7 is preferably a copper pipe.

[0025] In order to facilitate unwinding and rewinding, an unwinding mechanism may be provided in the baking chamber 1, and a rewinding mechanism may be provided in the cooling chamber 2. Of course, in some embodiments, a feeding chamber is provided at the front side of the baking chamber 1, and an unwinding mechanism is provided in the feeding chamber to unwind the material coil and then feed it into the baking chamber 1 for drying, and a receiving chamber is provided at the rear side of the cooling chamber 2, and a rewinding mechanism is provided in the receiving chamber to vacuum rewind the strip flowing out of the cooling chamber 2.

[0026] When the vacuum drying device for pole piece strip of the utility model is used, the vacuum tube 3 is connected to the vacuum equipment respectively to vacuumize the baking chamber 1 and the cooling chamber 2 respectively to achieve the required vacuum degree so as to facilitate the evaporation of water. When drying, the pole piece strip first enters the baking chamber 1, is dried by the drying device 5 in the baking chamber 1, and then enters the cooling chamber 2, is cooled to room temperature by the cooling device 6, and finally is rolled up by the winding mechanism. The vacuum drying device for pole piece strips of the utility model is provided with condensing tubes 7 for passing refrigerant, both ends of which extend outside the cavity, in the baking chamber 1 and the cooling chamber 2. In this way, refrigerant below 0°C can be passed into the condensing tube 7 during drying, so that the surface temperature of the condensing tube 7 is below 0°C. Once the water vapor in the baking chamber 1 and the cooling chamber 2 contacts the condensing tube 7, it will condense and accumulate ice on the condensing tube 7, thereby removing the water vapor in the baking chamber 1 and the cooling chamber 2, reducing the water vapor content in the baking chamber 1 and the cooling chamber 2, and solving the problem of inconvenient water removal of the device. In order to make the water vapor condense quickly and accumulate ice on the condensing tube 7, in the embodiment of the utility model, the refrigerant temperature is optimally -50°C.

[0027] The drying device 5 can adopt various existing heating devices. In the present utility model, preferably, the drying device 5 includes at least two heating rollers 52 arranged at intervals, and the pole piece strip 4 is wound on the heating rollers 52 in sequence, and one of them cooperates with one side of the pole piece strip 4, and one of them cooperates with the other side of the pole piece strip 4. The above-mentioned heating device adopts the heating roller 52 to directly heat the pole piece strip 4, and can heat both sides of the strip, with good heating effect, low energy consumption, more uniform heating of the strip, and better drying effect. The heating roller 52 preferably adopts the existing electromagnetic heating roller, which can control the temperature at ±1°C and can also respond quickly to temperature rise. The specific number of heating rollers 52 can be increased as needed. In the embodiment of the present utility model, the number of heating rollers 52 is 4, and two of them cooperate with one side of the pole piece strip 4, and two of them cooperate with the other side of the pole piece strip 4.

[0028] In the embodiment of the utility model, the drying device 5 further includes a preheating device 51 arranged in front of the heating roller 52 for preheating the pole piece strip 4, and the preheating device 51 is an infrared heating device. After the pole piece strip 4 is preheated by the infrared heating device, it is more convenient to heat the subsequent heating roller 52. The preheating device 51 is an infrared heating device, which can make the surface and internal temperature of the pole piece strip more evenly heated, and the preheating effect is better.

[0029] The cooling device 6 can adopt various existing cooling devices. In the present invention, preferably, the cooling device 6 includes at least two cooling rollers 61 arranged at intervals, and the cooling rollers 61 are provided with cooling channels for passing cooling medium, and the pole piece strips 4 are wound around the cooling rollers 61 in sequence, and one of them cooperates with one side of the pole piece strip 4, and the other cooperates with the other side of the pole piece strip 4. The above cooling device uses the cooling rollers 61 to directly cool the pole piece strip 4, and can cool both sides of the pole piece strip 4, with good cooling effect and energy saving.

[0030] The condenser tube 7 can be arranged arbitrarily. When the drying device 5 adopts the above-mentioned heating roller arrangement structure, it is best that the condenser tube 7 in the baking chamber 1 is arranged around the heating roller 52. The condenser tube 7 is arranged around the heating roller 52, which is conducive to the water vapor generated by the heating roller 52 to contact with the condenser tube 7, which is conducive to the condensation and dehydration of the condenser tube 7. When the cooling device 6 adopts the above-mentioned cooling roller arrangement structure, it is best that the condenser tube 7 in the cooling chamber 2 is arranged around the cooling roller 61. The condenser tube 7 is arranged around the cooling roller 61, which can make the water vapor around the cooling roller 61 contact with the condenser tube 7 and be condensed, which is most beneficial to prevent the water vapor from entering the strip for the second time when the strip is cooled, and is conducive to improving the drying effect of the strip.

[0031] In the embodiment of the utility model, the baking chamber 1 and the cooling chamber 2 are also connected to an inflation pipe 8 respectively, and an on-off control valve 81 is provided on the inflation pipe 8. The inflation pipe 8 is connected to a nitrogen gas source 9 to form a nitrogen replenishment system. When the water vapor in the baking chamber 1 or the cooling chamber 2 cannot be condensed by the condenser 7 therein in time, causing the water vapor in the chamber to exceed the required value, the on-off control valve 81 can be opened, and nitrogen can be discharged into the corresponding chamber through the nitrogen gas source 9. At the same time, the corresponding chamber is evacuated through a vacuum device to replace the water vapor in the chamber, reduce its water vapor content, and maintain the vacuum degree of the chamber.

[0032] In order to conveniently measure the moisture content in the baking chamber 1 and the cooling chamber 2 , humidity sensors are provided in the baking chamber 1 and the cooling chamber 2 .

[0033] In the utility model, when the vacuum electrode is baked, the infrared heating device is used to heat up the temperature first, so that the electrode can be preheated first. The electromagnetic heating roller can control the temperature at ±1°C and can also respond quickly to the temperature increase. Since the vacuum environment does not conduct heat, the electrode can continue to maintain the current temperature when it is not in contact with the electromagnetic heating roller. The cooling roller in the cooling chamber can quickly reduce the electrode to the set temperature. A condenser 7 is provided in the baking chamber 1 and the cooling chamber 2. A refrigerant of -50°C can be introduced through the condenser 7, so that the moisture baked out can be quickly adsorbed onto the condenser 7. The humidity sensor can monitor the humidity in the cavity, and the cavity environment with high humidity in the cavity can be replaced with a nitrogen supplement vacuum pumping system. The utility model utilizes that water vapor can quickly freeze and adsorb onto the copper tube at -50°C when it hits the copper tube, and nitrogen is injected and vacuumized to treat a part of the water vapor that is not adsorbed by deep cold, so as to improve the humidity environment in the cavity. Moreover, the condenser 7 and the nitrogen supplement vacuum pumping system in the utility model can be used separately or together, and can be flexibly applied according to actual production data to effectively solve the technical problem that the moisture baked out in the vacuum cavity enters the electrode again.

Claims

1. A vacuum drying device for pole piece strips, used for drying pole piece strips (4), comprising a drying device (5), a cooling device (6), a baking chamber (1) and a cooling chamber (2), characterized in that: The baking chamber (1) and the cooling chamber (2) are both sealed, the cooling chamber (2) is provided with a strip passage (21) whose one end is connected to the baking chamber (1), the baking chamber (1) and the cooling chamber (2) are both connected with a vacuum pipe (3), the drying device (5) is arranged in the baking chamber (1), the cooling device (6) is arranged in the cooling chamber (2), and the baking chamber (1) and the cooling chamber (2) are both provided with a condenser pipe (7) for passing a refrigerant, the two ends of which extend outside the chamber.

2. The electrode strip vacuum drying device according to claim 1, characterized in that: The drying device (5) comprises at least two heating rollers (52) arranged at intervals, and the pole piece strip (4) is wound around the heating rollers (52) in sequence, one of which cooperates with one side of the pole piece strip (4), and the other cooperates with the other side of the pole piece strip (4).

3. The electrode strip vacuum drying device according to claim 2, characterized in that: The heating roller (52) is an electromagnetic heating roller.

4. The electrode strip vacuum drying device according to claim 2 or 3, characterized in that: The drying device (5) further comprises a preheating device (51) arranged in front of the heating roller (52) for preheating the pole piece strip (4); the preheating device (51) is an infrared heating device.

5. The electrode strip vacuum drying device according to claim 1, characterized in that: The cooling device (6) comprises at least two cooling rollers (61) arranged at intervals, wherein a cooling channel for passing a cooling medium is provided inside the cooling rollers (61), and the pole piece strip (4) is wound around the cooling rollers (61) in sequence, and one of the cooling rollers cooperates with one side of the pole piece strip (4), and the other cooperates with the other side of the pole piece strip (4).

6. The electrode strip vacuum drying device according to claim 2, characterized in that: The condenser tube (7) in the baking chamber (1) is arranged around the heating roller (52).

7. The electrode strip vacuum drying device according to claim 5, characterized in that: The condenser tube (7) in the cooling chamber (2) is arranged around the cooling roller (61).

8. The electrode strip vacuum drying device according to claim 1, characterized in that: The baking chamber (1) and the cooling chamber (2) are also respectively connected to an inflation pipe (8), an on-off control valve (81) is provided on the inflation pipe (8), and the inflation pipe (8) is connected to a nitrogen gas source (9).

9. The electrode strip vacuum drying device according to claim 1, characterized in that: Humidity sensors are provided in both the baking chamber (1) and the cooling chamber (2).

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