Pole piece heating device and pole piece rolling system

Abstract

The utility model relates to a pole piece heating device and a pole piece rolling system. The pole piece heating device comprises a heating assembly, the heating assembly comprises a first heating surface and a second heating surface, the first heating surface and the second heating surface are oppositely arranged, so that a heating channel is formed between the first heating surface and the second heating surface, and the heating channel is used for penetrating through an empty foil area of a pole piece. And the first heating surface and the second heating surface of the heating assembly heat the upper surface and the lower surface of the empty foil area of the pole piece, so that the upper surface and the lower surface of the empty foil area are heated simultaneously. The empty foil area of the pole piece heated by the pole piece heating device is uniformly heated up and down, has higher consistency and better ductility, solves the problem of belt breakage of the pole piece in the empty foil area, and avoids wrinkles of the empty foil area due to simultaneous heating up and down of the pole piece.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage, in particular to a pole piece heating device and a pole piece rolling system. Background Art

[0002] A lithium battery pole piece includes a current collector and an active material layer coated on the current collector. After the active material layer is coated, the active material layer is relatively fluffy and has a low bonding strength with the current collector, and it needs to be rolled and compacted. After the pole piece is rolled, the energy density of the lithium battery can be increased, and the binder can firmly paste the electrode material on the current collector of the pole piece.

[0003] During the rolling process, the pole piece is in a tensioned state, and due to the different thicknesses of the coating area of the active material layer and the empty foil area as the pole ear on the pole piece, the extension during the rolling process is inconsistent, and the empty foil area is prone to tape breakage at the over-roller position. Summary of the Utility Model

[0004] Based on this, it is necessary to provide a pole piece heating device and a pole piece rolling system for solving the problem that the empty foil area is prone to tape breakage at the over-roller position.

[0005] In a first aspect, the present application provides a pole piece heating device, the pole piece heating device includes a heating component, the heating component includes a first heating surface and a second heating surface, the first heating surface and the second heating surface are arranged opposite to each other to form a heating channel between the first heating surface and the second heating surface, and the heating channel is used to heat the empty foil area of the pole piece.

[0006] In one embodiment, the heating component includes a U-shaped structure, two sides of the U-shaped structure respectively form the first heating surface and the second heating surface, and the U-shaped cavity of the U-shaped structure forms the heating channel.

[0007] In one embodiment, a first heating module and a second heating module are arranged inside the U-shaped structure, the first heating module is arranged adjacent to the first heating surface, and the second heating module is arranged adjacent to the second heating surface.

[0008] In one embodiment, the heating component includes a first heating roller and a second heating roller, the first heating roller and the second heating roller are arranged opposite to each other, the circumferential surface of the first heating roller is configured as the first heating surface, the circumferential surface of the second heating roller is configured as the second heating surface, and the space between the first heating roller and the second heating roller is configured as the heating channel.

[0009] In one embodiment, a first annular heating element is disposed inside the first heating roller, and the first annular heating element is disposed around and in contact with the inner surface of the first heating roller. A second annular heating element is disposed inside the second heating roller, and the second annular heating element is disposed around and in contact with the inner surface of the second heating roller.

[0010] In one embodiment, the pole piece heating device heats the first heating surface and / or the second heating surface by electromagnetic heating.

[0011] In one embodiment, the heating assembly has a cooling cavity for accommodating a cooling medium; the pole piece heating device further includes a cooling assembly for delivering the cooling medium into the cooling cavity.

[0012] In a second aspect, the present application further provides a pole piece rolling system, which includes:

[0013] A rolling assembly for rolling the pole piece;

[0014] The above-mentioned pole piece heating device, which is disposed upstream of the rolling assembly.

[0015] In one embodiment, the pole piece forms a coating area and empty foil areas on both sides of the coating area. The pole piece rolling system includes a pair of the pole piece heating devices, and the pair of the pole piece heating devices are respectively disposed in the empty foil areas on both sides.

[0016] In one embodiment, the pole piece rolling system further includes a passing roller assembly, and the passing roller assembly includes a first passing roller and a second passing roller; the pole piece heating device is disposed between the first passing roller and the second passing roller.

[0017] For the above-mentioned pole piece heating device and pole piece rolling system, the first heating surface and the second heating surface of the heating assembly heat the upper and lower surfaces of the empty foil area of the pole piece, so that the upper and lower surfaces of the empty foil area are heated simultaneously. After being heated by the pole piece heating device, the upper and lower parts of the empty foil area of the pole piece are heated evenly and have a high consistency, and have good ductility, solving the problem of belt breakage in the empty foil area of the pole piece. At the same time, since the pole piece is heated from above and below simultaneously, the occurrence of wrinkles in the empty foil area is avoided. Description of the Drawings

[0018] Figure 1 Is a schematic structural diagram of a pole piece;

[0019] Figure 2 Is a schematic structural diagram when the heating assembly is of a U-shaped structure in one embodiment;

[0020] Figure 3 Is a schematic structural diagram when the heating assembly is a heating roller in one embodiment;

[0021] Figure 4 Schematic diagram of the pole piece rolling system using a U-shaped structure heating component in an embodiment;

[0022] Figure 5 Schematic diagram of the pole piece rolling system using a heating roller as a heating component in an embodiment;

[0023] Figure 6 Schematic diagram of the positional relationship between the heating roller used as a heating component and the pole piece in an embodiment.

[0024] Explanation of the reference numerals in the drawings:

[0025] 10. Pole piece; 11. Coating area; 12. Empty foil area; 20. Heating component; 21. First heating surface; 22. Second heating surface; 23. Heating channel; 24. Cooling cavity; 31. First heating module; 32. Second heating module; 41. First heating roller; 42. Second heating roller; 43. First circular heating element; 44. Second circular heating element; 50. Pole piece rolling system; 51. Rolling component; 52. First over-roller; 53. Second over-roller. Detailed implementation manners

[0026] In order to make the above objects, features, and advantages of the present invention more obvious and understandable, the following describes the detailed implementation manners of the present invention with reference to the accompanying drawings. Many specific details are set forth in the following description in order to fully understand the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present utility model, the meaning of "a plurality of" is at least two, such as two, three, etc., unless otherwise specifically defined.

[0029] In the present utility model, unless otherwise clearly defined and limited, terms such as "installed", "connected", "joined", "fixed", etc. shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0030] In the present utility model, unless otherwise clearly defined and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over" and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath" and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0031] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it may be directly on the other element or there may also be an intermediate element. When an element is considered to be "connected" to another element, it may be directly connected to the other element or there may be an intermediate element at the same time. The terms "vertical", "horizontal", "up", "down", "left", "right" and similar expressions used herein are for illustrative purposes only and do not represent the only implementation.

[0032] The lithium battery electrode sheet includes a current collector and an active material layer coated on the current collector. After the active material layer is coated, the active material layer is relatively fluffy and has a low bonding strength with the current collector, and it needs to be roll-compacted. After the electrode sheet is roll-compacted, the energy density of the lithium battery can be increased, and the binder can firmly paste the electrode material on the current collector of the electrode sheet. See Figure 1 Generally, the active material is located in the middle area of the electrode sheet 10 to form a coating area 11, and both sides of the coating area 11 are empty foil areas 12, and the empty foil areas 12 are used to form electrode tabs.

[0033] Refer to Figure 2 , Figure 2 which shows a schematic structural view of the pole piece heating device in an embodiment of the present invention. The pole piece heating device provided by an embodiment of the present invention includes a heating assembly 20, and the heating assembly 20 is used to heat the empty foil area 12 of the pole piece 10. The heating assembly 20 includes a first heating surface 21 and a second heating surface 22, and the first heating surface 21 and the second heating surface 22 are arranged opposite to each other to form a heating channel 23 between the first heating surface 21 and the second heating surface 22. The heating channel 23 is used to pass through the empty foil area 12 of the pole piece 10 and heat the empty foil area 12.

[0034] The first heating surface 21 and the second heating surface 22 are arranged opposite to each other and have a gap therebetween. The pole piece 10 can pass through the gap between the first heating surface 21 and the second heating surface 22. When the empty foil area 12 of the pole piece 10 is located between the first heating surface 21 and the second heating surface 22, the empty foil area 12 is heated.

[0035] It can be understood that the gap between the first heating surface 21 and the second heating surface 22 should be greater than the thickness of the pole piece 10, especially at least greater than the thickness of the empty foil area 12 on the pole piece 10. In this way, the empty foil area 12 of the pole piece 10 can pass through the gap between the first heating surface 21 and the second heating surface 22, and the first heating surface 21 and the second heating surface 22 heat the front and back surfaces of the pole piece 10, so as to increase the temperature of the empty foil area 12 and improve the ductility of the empty foil area 12.

[0036] In the above-mentioned pole piece heating device, the first heating surface 21 and the second heating surface 22 of the heating assembly 20 heat the upper and lower surfaces of the empty foil area 12 of the pole piece 10, so that the upper and lower surfaces of the empty foil area 12 are heated simultaneously. After being heated by the pole piece heating device, the upper and lower parts of the empty foil area 12 of the pole piece 10 are heated evenly and have a high degree of consistency, with good ductility, solving the problem of tape breakage in the empty foil area 12 of the pole piece 10. At the same time, since the pole piece 10 is heated from above and below simultaneously, the occurrence of wrinkles in the empty foil area 12 is avoided.

[0037] In some feasible implementation manners, the first heating surface 21 and / or the second heating surface 22 can be the heating surface of a heating element, and the heating element can be a resistance heating element, a heat conduction heating element, a radiation heating element, etc. A resistance heating element refers to generating heat using resistance. Optionally, the heating element is a high-resistance conductor that generates heat when current passes through it, thereby realizing the heating of the pole piece 10. An electromagnetic heating element uses the heat generated when current passes through a conductor to heat. Optionally, the heating element can be a metal element, and eddy currents are formed on the heating element based on the principle of electromagnetic induction, and then heat is generated. A radiation heating element heats an object by radiating heat. Optionally, the heating element can be an infrared heater, and heating is realized through infrared radiation.

[0038] SeeFigure 2 , in an exemplary embodiment, the heating assembly 20 includes a U-shaped structure. Two sides of the U-shaped structure respectively form a first heating surface 21 and a second heating surface 22, and the U-shaped cavity of the U-shaped structure forms a heating channel 23. One side of the U-shaped structure is open, facilitating the movement of the pole piece 10, so that the pole piece 10 has a certain distance from the heating assembly 20, avoiding the pole piece 10 colliding with the heating assembly 20 during the production process.

[0039] Both ends or both sides of the U-shaped structure are bent inward to form an open central space. Wherein, the U-shaped structure includes a first side, a second side, and an intermediate section. The intermediate section is located in the middle of the first side and the second side and connects the two. Optionally, the bending points of the U-shaped structure, that is, the connection points between the first side and the intermediate section, and the connection points between the second side and the intermediate section can be arc-shaped or right-angled. The open central space formed by surrounding the first side, the second side, and the intermediate section is called the U-shaped cavity.

[0040] In this embodiment, the surface of the first side facing the U-shaped cavity can be the first heating surface 21, and the surface of the second side facing the U-shaped cavity can be the second heating surface 22. The open central space is the heating channel 23 for passing through the empty foil area 12 of the pole piece 10. Thus, when the empty foil area 12 of the pole piece 10 passes through the open central space, the first heating surface 21 and the second heating surface 22 can heat the upper and lower surfaces of the pole piece 10.

[0041] Optionally, the U-shaped structure is an integral structure, which is convenient for processing and movement. Optionally, the U-shaped structure is a symmetric structure. When the pole piece 10 passes through the symmetry axis of the U-shaped structure, when the distances from the first heating surface 21 and the second heating surface 22 to the pole piece 10 are equal, and the heating powers of the first heating surface 21 and the second heating surface 22 are the same, the heating temperatures on the upper and lower surfaces of the empty foil area 12 are the same, avoiding wrinkles caused by uneven heating.

[0042] In an exemplary embodiment, a first heating module 31 and a second heating module 32 are arranged inside the U-shaped structure. The first heating module 31 is arranged adjacent to the first heating surface 21, and the second heating module 32 is arranged adjacent to the second heating surface 22. In some feasible implementation manners, the first heating module 31 is located inside the first side and is attached to the first heating surface 21, and the second heating module 32 is located inside the second side and is attached to the second heating surface 22. Thus, when the first heating module 31 generates heat, it can increase the temperature of the first heating surface 21, and when the second heating module 32 generates heat, it can increase the temperature of the second heating surface 22.

[0043] Optionally, the first heating module 31 and / or the second heating module 32 can be a resistance heating element, a heat conduction heating element, a radiation heating element, etc., as long as it can meet the requirement of increasing the temperatures of the first heating surface 21 and the second heating surface 22.

[0044] See Figure 3 , in another exemplary embodiment, the heating assembly 20 includes a first heating roller 41 and a second heating roller 42. The first heating roller 41 and the second heating roller 42 are arranged opposite to each other. The circumferential surface of the first heating roller 41 is configured as a first heating surface 21, the circumferential surface of the second heating roller 42 is configured as a second heating surface 22, and the space between the first heating roller 41 and the second heating roller 42 is configured as a heating channel 23.

[0045] Wherein, the first heating roller 41 and / or the second heating roller 42 is cylindrical and is driven to rotate by a driving mechanism. The empty foil area 12 of the pole piece 10 passes through the space between the first heating roller 41 and the second heating roller 42. The first heating roller 41 and the second heating roller 42 can rotate self - sufficiently to heat the upper and lower surfaces of the empty foil area 12 of the pole piece 10. Optionally, the first heating roller 41 and / or the second heating roller 42 can be made of wear - resistant and corrosion - resistant materials to ensure its long - term stability and performance during the manufacturing process.

[0046] Since the first heating roller 41 and / or the second heating roller 42 is cylindrical, a conical area is formed between the heating roller and the pole piece 10 during the transmission of the pole piece 10. During the process of the pole piece 10 approaching from far to near, the closest distance between the pole piece 10 and the heating roller gradually decreases, rather than remaining unchanged as in the U - shaped structure. Therefore, the temperature of the pole piece 10 gradually increases when it is heated, avoiding the adverse effects caused by the sudden increase in the temperature of the heated part of the empty foil area 12.

[0047] In one of the embodiments, a first circular heating element 43 is arranged inside the first heating roller 41, and the first circular heating element 43 surrounds and fits on the inner surface of the first heating roller 41. A second circular heating element 44 is arranged inside the second heating roller 42, and the second circular heating element 44 surrounds and fits on the inner surface of the second heating roller 42.

[0048] The first circular heating element 43 is arranged inside the first heating roller 41 and surrounds the inner surface of the first heating roller 41 for one week. In this way, the first circular heating element can increase the temperature of the roller surface of the first heating roller 41 to form a first heating surface. The second circular heating element 44 is arranged inside the second heating roller 42 and surrounds the inner surface of the second heating roller 42 for one week. In this way, the second circular heating element can increase the temperature of the roller surface of the second heating roller 42 to form a second heating surface.

[0049] By arranging the circular heating element on the inner surface of the roller instead of setting a heating center in the central area, the circular heating element can improve the heat utilization rate and enable the temperature change of the heating element to be efficiently reflected on the surface of the heating roller.

[0050] In one embodiment, the electrode sheet heating device heats the first heating surface 21 and / or the second heating surface 22 by electromagnetic heating. Electromagnetic heating refers to the use of the principle of electromagnetic induction. When a conductor is placed in a changing magnetic field, the change in magnetic flux will induce circular currents inside the conductor, and these currents will generate damping inside the conductor and be converted into heat energy. Specifically in this embodiment, the first heating surface 21 and / or the second heating surface 22 are at least partially made of a metal material. When the first heating surface 21 and / or the second heating surface 22 are placed in a changing magnetic field, eddy currents will be generated inside, and these eddy currents will cause the conductor to heat up.

[0051] Based on the principle of electromagnetic induction, only by setting the heating component 20 in a changing magnetic field, it can generate heat based on the principle of electromagnetic induction, without setting other heat sources inside the heating component 20, reducing the volume of the heating component 20, and enabling it to be adapted to the existing production process of the electrode sheet 10. On the other hand, using the principle of electromagnetic induction does not require adding additional heat sources, saving space, and a cooling cavity can be formed within the saved space.

[0052] In an exemplary embodiment, the heating component 20 has a cooling cavity 24 for accommodating a cooling medium; the electrode sheet heating device further includes a cooling component for delivering the cooling medium into the cooling cavity 24. When the thickness of the electrode sheet 10 is different, or the foil material and / or the active material of the electrode sheet are different, etc., the heating temperature thereof should be adjusted adaptively. Adjustment of the products on the production line may require quickly reducing the heating temperature of the heating component 20. By setting the cooling cavity 24 inside the heating component 20 and delivering the cooling medium into the cooling cavity 24 through the cooling component, the heating component 20 can be moderately cooled when its temperature is too high, so that the temperature of the electrode sheet 10 is maintained within a reasonable range.

[0053] See Figure 2 When the heating component 20 is a U-shaped structure, the first side, the second side, and the middle section of the U-shaped structure are hollow inside to form the cooling cavity 24, enabling the cooling medium to pass through. See Figure 3 When the heating component 20 includes a first heating roller 41 and a second heating roller 42, the inside of the first heating roller 41 and / or the second heating roller 42 has a hollow structure, and the hollow structure serves as the cooling cavity 24.

[0054] See Figure 4 and Figure 5 , Figure 4 shows a pole piece rolling system 50 in one embodiment, Figure 5 shows a pole piece rolling system 50 in another embodiment, wherein, Figure 4 a U-shaped heating component 20 is used in Figure 5A heating roller is used as the heating component 20. The present application also provides a pole piece rolling system 50, which includes a rolling component 51 for rolling the pole piece 10; a pole piece heating device, and the pole piece heating device is arranged upstream of the rolling component 51.

[0055] The rolling component 51 includes rollers, including an upper roller and a lower roller. The upper roller and the lower roller can press the electrode piece 10 through a mechanical system or a hydraulic system. The surface of the rollers usually needs to be specially treated to ensure its surface smoothness and wear resistance, so as to avoid damaging the electrode piece 10.

[0056] The pole piece 10 enters from one end of the rolling component 51 and exits from the other end. Therefore, it is divided into upstream and downstream along the moving direction of the pole piece 10. That is, the upstream of the rolling component 51 is the input end, and the unrolled pole piece 10 is input into the rolling component 51. The downstream of the rolling component 51 is the output end, and the rolled pole piece 10 is output. During rolling, it is more likely to break under the dual action of the tension force and the rolling force of the rolling component 51. The pole piece heating device 20 is arranged upstream of the rolling component 51. By heating the empty foil area 12, the temperature of the empty foil area 12 is increased and the ductility is increased, so as to avoid the breakage of the empty foil area 12 of the pole piece 10 after being rolled by the rolling component 51.

[0057] As Figure 6 shown, in an exemplary embodiment, the pole piece 10 forms a coating area 11 and empty foil areas 12 on both sides of the coating area 11. The pole piece rolling system 50 includes a pair of pole piece heating devices, and the pair of pole piece heating devices are respectively arranged in the empty foil areas 12 on both sides. Optionally, in order to improve the production efficiency of the pole piece 10, the middle of the pole piece 10 is the coating area 11, and the empty foil areas 12 are formed on both sides of the coating area 11, so that pole ears can be formed on both sides. In this embodiment, the pole piece rolling system 50 includes two pole piece heating devices, one of the pole piece heating devices is located in the empty foil area 12 on one side of the pole piece 10, and the other pole piece heating device is located in the empty foil area 12 on the other side of the pole piece 10, so as to heat the empty foil areas 12 on both sides of the pole piece 10 at the same time.

[0058] As Figure 4 shown, in an exemplary embodiment, the pole piece rolling system 50 further includes a deflector roll assembly, and the deflector roll assembly includes a first deflector roll 52 and a second deflector roll 53; the pole piece heating device is arranged between the first deflector roll 52 and the second deflector roll 53. The deflector roll assembly is used to adjust the direction of the pole piece 10 and increase the ductility of the pole piece 10.

[0059] Optionally, the first over-roller 52 is configured to adjust the direction of the pole piece 10 passing through the first over-roller 52 by a first angle, and the second over-roller 53 is configured to adjust the pole piece 10 passing through the second over-roller 53 by a second angle. After passing through the first over-roller 52, the output direction of the pole piece 10 changes. The tension of the pole piece 10 between the first over-roller 52 and the second over-roller 53 is relatively high and it is more likely to break. Further, a pole piece heating device can also be arranged between the first over-roller 52 and the second over-roller 53, which can improve the ductility of the empty foil area 12 of the pole piece 10 and avoid its breakage.

[0060] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0061] The above embodiments only represent several implementation manners of the present utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the utility model patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present utility model, several deformations and improvements can still be made, and these all belong to the protection scope of the present utility model. Therefore, the protection scope of the utility model patent shall be subject to the appended claims.

Claims

1. A pole piece heating device, characterized in that: The pole piece heating device includes a heating component, and the heating component includes a first heating surface and a second heating surface. The first heating surface and the second heating surface are arranged opposite to each other to form a heating channel between the first heating surface and the second heating surface. The heating channel is used to heat the empty foil area of ​​the pole piece.

2. The pole piece heating device according to claim 1, characterized in that: The heating assembly comprises a U-shaped structure, two sides of the U-shaped structure respectively form the first heating surface and the second heating surface, and a U-shaped cavity of the U-shaped structure forms the heating channel.

3. The pole piece heating device according to claim 2, characterized in that: A first heating module and a second heating module are arranged inside the U-shaped structure. The first heating module is arranged adjacent to the first heating surface, and the second heating module is arranged adjacent to the second heating surface.

4. The pole piece heating device according to claim 1, characterized in that: The heating assembly includes a first heating roller and a second heating roller, the first heating roller and the second heating roller are arranged opposite to each other, the circumferential surface of the first heating roller is configured as a first heating surface, the circumferential surface of the second heating roller is configured as a second heating surface, and the space between the first heating roller and the second heating roller is configured as the heating channel.

5. The pole piece heating device according to claim 4, characterized in that: A first annular heating element is disposed inside the first heating roller and surrounds and fits the inner surface of the first heating roller. A second annular heating element is disposed inside the second heating roller and surrounds and fits the inner surface of the second heating roller.

6. The pole piece heating device according to claim 1, characterized in that: The pole piece heating device heats the first heating surface and / or the second heating surface by electromagnetic heating.

7. The pole piece heating device according to claim 1, characterized in that: The heating component has a cooling cavity for accommodating a cooling medium; the pole piece heating device also includes a cooling component, and the cooling component is used to transport the cooling medium into the cooling cavity.

8. A pole piece rolling system, characterized in that: The pole piece rolling system comprises: Roller pressing assembly, used for pressing pole pieces; The pole piece heating device according to any one of claims 1 to 7 is arranged upstream of the rolling assembly.

9. The pole piece rolling system according to claim 8, characterized in that: The pole piece forms a coating area and empty foil areas on both sides of the coating area. The pole piece rolling system includes a pair of pole piece heating devices, which are respectively arranged in the empty foil areas on both sides.

10. The pole piece rolling system according to claim 8, characterized in that: The pole piece rolling system further includes a roller assembly, which includes a first roller and a second roller; the pole piece heating device is disposed between the first roller and the second roller.

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