A combined pole piece drying oven

Abstract

The utility model relates to the lithium battery pole piece production technical field, more particularly, provide a combined pole piece drying oven, including hot -blast device and heating roller subassembly, heating roller subassembly includes a plurality of heating roller, heating roller is used for even heating pole piece, pole piece surrounds two heating rollers and forms s type's running path in turn, and hot -blast device sets up in the both sides of running path. Through heating roller and pole piece contact heat conduction heating drying to pole piece, make pole piece and heating roller contact's position all even heating, reduce the edge of pole piece active material occurrence curling phenomenon's occurrence, and because pole piece surrounds heating roller and formed s type's running path, to pole piece with the reverse curve state heating can make pole piece's different parts interact when deformation, dispersive uneven stress, thereby avoided a certain part excessive stress, reduced the overall deformation makes pole piece not easy to occur bending and wrinkle.

Description

Technical Field

[0001] This utility model relates to the field of lithium battery electrode production technology, and more specifically, to a combined electrode drying oven. Background Technology

[0002] In the production process of lithium batteries, the electrode sheets or separators need to be coated, and the coated substrate needs to be dried. The coating substrate is dried to remove the solvent and ensure the performance of the battery. This drying process is generally completed using an oven.

[0003] The drying methods used in existing ovens generally employ hot air to heat the electrode sheets. After coating, the foil or electrode sheet of the lithium battery coating machine enters the oven for drying. During the drying process, due to factors such as the horizontal wind speed or coating formulation, the drying efficiency of the coating layer varies, or the additives in the slurry evaporate too quickly, causing the edges of the foil or electrode sheet to curl at the blank areas on both sides in the oven, resulting in material waste.

[0004] Therefore, there is an urgent need to invent a combined electrode drying oven. Utility Model Content

[0005] The purpose of this invention is to provide a combined electrode drying oven that addresses the shortcomings of existing technologies, thereby reducing edge curling caused by inconsistent drying efficiency of electrode sheets and reducing the occurrence of bending and wrinkling of electrode foil.

[0006] To solve the above-mentioned technical problems, this application adopts the following technical solution:

[0007] A combined electrode drying oven is provided, including a hot air device and a heating roller assembly. The heating roller assembly includes multiple heating rollers for uniformly heating the electrode. The electrode sequentially forms an S-shaped conveyor path around the heating roller. The hot air device is disposed on both sides of the conveyor path for delivering hot air to the electrode.

[0008] Furthermore, the hot air device is positioned within the area of ​​the contact angle between the electrode and the heating roller.

[0009] Furthermore, the hot air device includes a static pressure chamber and multiple air nozzles, all of which are connected to the static pressure chamber and are evenly distributed along the outer periphery of the heating roller.

[0010] Furthermore, the shape of the static pressure chamber matches the shape of the heating roller.

[0011] Furthermore, the nozzle is a slit-type nozzle whose length direction is perpendicular to the direction of the electrode tape.

[0012] Furthermore, the heating roller is a hot oil roller, and uniformly distributed flow channels are provided along the roller surface of the hot oil roller. The hot oil roller is connected to the hot oil generator through the flow channels, and the hot oil generator can control the hot oil temperature, thereby controlling the roller surface temperature of the hot oil roller.

[0013] Furthermore, the hot oil rollers are symmetrically distributed vertically.

[0014] Furthermore, a return air chamber is provided inside the oven, and the return air chamber is located on both sides of the hot air device.

[0015] Furthermore, negative pressure chambers are provided at both the electrode inlet and outlet of the oven.

[0016] Furthermore, the oven body is filled with an insulation layer.

[0017] The beneficial effects of this utility model are as follows: By setting a heating roller, the electrode is heated and dried through heat conduction in contact with the heating roller. Because the temperature of the heating roller is more uniform, the contact area between the electrode and the heating roller is heated evenly, keeping the drying efficiency of the coating layer at different positions of the electrode relatively small, reducing the occurrence of edge curling of the active material at the edge of the electrode. Furthermore, since the electrode forms an S-shaped conveyor path around the heating roller, when the electrode passes through the heating roller, local areas will have different degrees of expansion and contraction due to thermal expansion. Heating the electrode in a reverse bending state allows different parts of the electrode to interact during deformation, dispersing uneven stress, thereby avoiding excessive stress on any part, reducing overall deformation, and making the electrode less prone to bending and wrinkling. The heating roller can also provide good support when heating the electrode, reducing the deformation caused by stress on the electrode at high temperatures, improving the stability of the production process and product quality. The hot air device can promptly blow away the solvent and moisture evaporated by the electrode, and at the same time, the hot air device can also heat the electrode to improve drying efficiency, reducing the size of the drying oven. Attached Figure Description

[0018] The accompanying drawings, which are included to provide a further understanding of the present invention and constitute a part of this invention, illustrate exemplary embodiments of the present invention and are used to explain the present invention, but do not constitute an undue limitation of the present invention. In the drawings:

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Wherein: 1-Hot air device; 11-Air nozzle; 12-Static pressure chamber; 2-Heating roller assembly; 21-Heating roller; 211-Hot oil roller; 3-Belt conveyor path; 4-Return air chamber; 5-Negative pressure chamber. Detailed Implementation

[0021] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application pertains. The terminology used in the specification of this application is for the purpose of describing specific embodiments only and is not intended to limit this application.

[0022] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] Although this application discloses preferred embodiments as described above, it is not intended to limit the claims. Any person skilled in the art can make several possible changes and modifications without departing from the concept of this application. Therefore, the scope of protection of this application should be determined by the scope defined in the claims of this application.

[0024] The applicant has discovered that the hot air drying method used in existing ovens is difficult to control and the airflow from the air outlet is uneven, resulting in inconsistent drying rates of different parts of the electrode sheet in the transverse direction perpendicular to the belt direction. After drying, the electrode coating shrinks, and when the drying rate is inconsistent, the shrinkage rate of different parts of the coating layer is different, which leads to stress and eventually causes the edge of the electrode sheet to curl.

[0025] This application, by setting a heating roller, changes the drying method of the electrode sheet, so that the electrode sheet is heated evenly and the drying rate of each position remains relatively consistent. Furthermore, since the heating is done at the heating roller, the stress on the electrode sheet can be dispersed on the roller surface during the heating and drying process, reducing the occurrence of wrinkles.

[0026] like Figure 1As shown, this application provides a combined electrode drying oven, including a hot air device 1 and a heating roller assembly 2. The heating roller assembly 2 includes multiple heating rollers 21, which are used to uniformly heat the electrode. The roller surface of the heating roller 21 can be heated. When the electrode enters the oven, it adheres closely to the roller surface of the heating roller 21, allowing the temperature of the heating roller 21 to be transferred to the electrode, thereby increasing the temperature of the electrode and causing the solvent in the electrode to evaporate, thus achieving drying. The electrode sequentially forms an S-shaped conveyor path 3 around the heating roller 21. That is, when the electrode passes around the first heating roller 21 and then passes around the second heating roller 21, it chooses to pass around one side of the first heating roller 21. This method makes the electrode form an S-shape, so that different parts of the electrode interact with each other during deformation. The method disperses uneven stress, thereby avoiding excessive stress on a certain part and reducing overall deformation, making the electrode less prone to bending and wrinkling. After forming an S-shaped conveyor path 3, it is beneficial for the electrode to adhere tightly to the heating roller 21, which can reduce thermal resistance and facilitate the heat transfer of the heating roller 21 to the electrode. The hot air device 1 is set on both sides of the conveyor path 3 to deliver hot air to the electrode, which can blow away the evaporated solvent. The hot air blown out by the hot air device 1 can also dry the electrode, improve the drying efficiency of the electrode, and help to reduce the volume of the drying oven. Since the heating roller 21 dries one side of the electrode and the hot air dries the other side, the drying rate of the active material on both sides of the electrode is kept relatively consistent, which can reduce the deformation of the electrode.

[0027] Preferably, the hot air device 1 is arranged within the area of ​​the contact angle between the electrode and the heating roller 21, that is, within the area where the electrode directly contacts and wraps the heating roller 21. This is because uneven heating on both sides of the electrode may increase the internal stress of the electrode, causing deformation of the electrode. The steam formed after the electrode is heated by the heating roller 21 needs to be discharged in time. This arrangement allows the steam on the surface of the electrode to be discharged quickly, improving the drying efficiency. Heating both sides of the electrode at the same time is beneficial to the uniformity of the temperature during electrode heating and improves the drying efficiency.

[0028] Preferably, the hot air device 1 includes a static pressure chamber 12 and multiple air nozzles 11. All air nozzles 11 are connected to the static pressure chamber 12 and are evenly distributed along the outer periphery of the heating roller 21. The pressure at each position in the static pressure chamber 12 remains consistent. Connecting multiple air nozzles 11 to the same static pressure chamber 12 can maintain the uniform air velocity of each air nozzle 11, so that the drying rate of each position of the electrode sheet is uniform.

[0029] Preferably, the shape of the static pressure chamber 12 matches the shape of the heating roller 21. Matching the shape of the static pressure chamber 12 with the shape of the heating roller 21 can keep the distance from each nozzle 11 to the electrode consistent, thus making the wind speed of each nozzle 11 consistent.

[0030] Preferably, the nozzle 11 is a slit-type nozzle 11 with its length direction perpendicular to the electrode belt direction. Setting the nozzle 11 as a slit-type nozzle 11 is beneficial to maintaining a consistent air velocity in the lateral direction and ensuring uniformity of electrode drying.

[0031] Preferably, the heating roller 21 is a hot oil roller 211, with uniformly distributed flow channels along the roller surface of the hot oil roller 211. The hot oil roller 211 is connected to the hot oil generator through the flow channels. The hot oil generator can control the temperature of the hot oil, thereby controlling the roller surface temperature of the hot oil roller 211. The uniformly distributed flow channels on the surface of the hot oil roller 211, and the temperature and flow rate of the hot oil in the flow channels controlled by the hot oil generator, can control the temperature of the roller surface of the hot oil roller 211 to remain uniform, so that the electrode sheet is uniformly heated after passing through the hot oil roller 211.

[0032] Preferably, the hot oil rollers 211 are symmetrically distributed vertically, which is beneficial to the layout of the hot air device 1 and the convenience of connecting with external devices.

[0033] Preferably, a return air chamber 4 is provided in the oven, and the return air chamber 4 is located on both sides of the hot air device 1. The air blown out from the air nozzle 11 flows over the surface of the electrode and enters the return air chamber 4 for processing, which is beneficial to maintaining the circulation of gas in the oven. It is advantageous to have return air chambers 4 on both sides of the hot air device 1.

[0034] Preferably, negative pressure chambers are provided at both the inlet and outlet of the oven electrode. The negative pressure chambers can extract gas to maintain negative pressure inside the oven, preventing air from flowing into the room and causing heat to escape and be conducted into the room.

[0035] Preferably, the oven body is filled with an insulation layer. The insulation layer can reduce the heat exchange between the oven body and the outside environment, reduce the heat loss, and play a role in energy saving and environmental protection. The insulation layer material can be aluminum silicate, which has good insulation performance as well as good heat resistance.

[0036] The specific working principle is as follows: The electrode enters the oven through the oven inlet and the negative pressure chamber, and is wound around the heating roller 21 along the S-shaped conveyor path 3. The temperature of the heating roller 21 rises, and the temperature and flow rate of the hot oil in the flow channel of the heating roller 21 are controlled by the hot oil machine to control the uniform temperature of the surface of the heating roller 21. After the electrode contacts the heating roller 21, the temperature rises and the electrode is dried. At the same time, the nozzle 11 of the hot air device 1 blows hot air into a section of the electrode within the wrap angle with the heating roller 21, so that the vapor of the solvent evaporated from the electrode is blown away from the surface of the electrode. At the same time, the hot air dries the surface of the electrode. After passing through the surface of the electrode, the hot air enters the return air chamber 4, is processed, and then re-enters the nozzle 11 to blow hot air. After the electrode is dried, it leaves the oven through the negative pressure chamber and the oven outlet.

[0037] The foregoing description illustrates and describes several preferred embodiments of the present invention. However, as previously stated, it should be understood that the present invention is not limited to the forms disclosed herein and should not be construed as excluding other embodiments. It can be used in various other combinations, modifications, and environments, and can be altered within the scope of the present invention's conception through the foregoing teachings or related technical or knowledge. Any modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention should be protected within the scope of the appended claims.

Claims

1. A combined electrode drying oven, characterized in that: The device includes a hot air device (1) and a heating roller assembly (2). The heating roller assembly (2) includes multiple heating rollers (21). The heating rollers (21) are used to uniformly heat the electrode sheets. The electrode sheets form an S-shaped conveyor path (3) around the heating rollers (21) in sequence. The hot air device (1) is disposed on both sides of the conveyor path (3) and is used to deliver hot air to the electrode sheets.

2. The combined electrode drying oven according to claim 1, characterized in that: The hot air device (1) is positioned within the area of ​​the contact angle between the electrode and the heating roller (21).

3. The combined electrode drying oven according to claim 2, characterized in that: The hot air device (1) includes a static pressure chamber (12) and a plurality of air nozzles (11), all of which are connected to the static pressure chamber (12) and are evenly distributed along the outer periphery of the heating roller (21).

4. The combined electrode drying oven according to claim 3, characterized in that: The shape of the static pressure chamber (12) matches the shape of the heating roller (21).

5. The combined electrode drying oven according to claim 3, characterized in that: The nozzle (11) is a slit-type nozzle (11) whose length direction is perpendicular to the direction of the electrode strip.

6. The combined electrode drying oven according to claim 1, characterized in that: The heating roller (21) is a hot oil roller (211). A uniformly distributed flow channel is provided along the roller surface of the hot oil roller (211). The hot oil roller (211) is connected to the hot oil machine through the flow channel. The hot oil machine can control the hot oil temperature, thereby controlling the roller surface temperature of the hot oil roller (211).

7. The combined electrode drying oven according to claim 6, characterized in that: The hot oil rollers (211) are symmetrically distributed vertically.

8. The combined electrode drying oven according to claim 2, characterized in that: A return air chamber (4) is provided inside the oven, and the return air chamber (4) is located on both sides of the hot air device (1).

9. The combined electrode drying oven according to claim 1, characterized in that: Negative pressure chambers (5) are provided at both the electrode inlet and outlet of the oven.

10. The combined electrode drying oven according to claim 1, characterized in that: The oven body is filled with an insulation layer.

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