Compression roller and rolling device

Abstract

The utility model relates to the technical field of battery manufacturing equipment, and discloses a compression roller and a rolling device. The rolling device comprises a supporting mechanism, a pressing roller and a second roller, the pressing roller and the second roller are both rotatably installed on the supporting mechanism, a gap is formed between the pressing roller and the second roller, the composite pole piece can pass through the gap between the pressing roller and the second roller, the composite pole piece comprises a composite area and an empty foil area, the pressing roller comprises a first rolling area and a second rolling area in the axial direction, and the first rolling area is located between the first rolling area and the second rolling area. The first rolling area is used for rolling the composite area, the second rolling area is used for rolling the empty foil area, and when the compression roller rolls the composite pole piece, the acting force of the second rolling area on the empty foil area is smaller than that of the first rolling area on the composite area. According to the rolling device disclosed by the utility model, through the arrangement of the compression roller, the empty foil area of the rolled composite pole piece does not have wrinkles.

Description

Technical Field

[0001] The utility model relates to the technical field of battery manufacturing equipment, in particular to a pressing roller and a rolling device. Background Art

[0002] In the manufacturing process of lithium batteries, the electrode sheet compounding is a very important step. Usually, when the electrode sheet is compounded, the composite layer 120 (specifically, it can be a solid electrolyte, a diaphragm, a lithium supplement layer, etc.) is stacked on the active material layer 112 of the electrode sheet 110 (including a substrate 111 and an active material layer 112 set on the substrate 111), and is compounded together by rolling a rolling device. In order to ensure that the composite electrode sheet 110 (hereinafter referred to as the composite electrode sheet 100) has a uniform thickness in the width direction, the roller of the rolling device in the prior art adopts a rubber roller, and the surface of the rubber roller has elastic deformation ability. Therefore, during the rolling process, the rubber roller can be more fully in contact with each position of the composite electrode sheet 100.

[0003] like Figure 1 As shown, the composite electrode 100 includes a hollow foil area 140 (including only a substrate 111) and a composite area 130 (including a substrate 111, an active material layer 112 and a composite layer 120 along the thickness direction). The ductility of the hollow foil area 140 is different from that of the composite area 130. When a rubber roller is used for composite rolling, the elongation of the hollow foil area 140 is greater than that of the composite area 130, which causes the hollow foil area 140 to easily wrinkle, thereby causing the quality of the tabs of the battery cell manufactured from the composite electrode 100 to fail to meet the use requirements.

[0004] Therefore, there is an urgent need for a pressing roller and a rolling device to solve the above technical problems. Utility Model Content

[0005] One purpose of the utility model is to provide a pressing roller, which can avoid wrinkles in the empty foil area when rolling the composite pole piece.

[0006] Another object of the utility model is to provide a rolling device, by providing the above-mentioned pressing roller, the composite pole piece after rolling will not have wrinkles.

[0007] To achieve this purpose, the utility model adopts the following technical solutions:

[0008] A pressing roller is used for rolling a composite pole piece, wherein the composite pole piece includes a composite area and a hollow foil area. The pressing roller includes a first rolling area and a second rolling area along the axial direction. The first rolling area is used for rolling the composite area, and the second rolling area is used for rolling the hollow foil area. When the pressing roller rolls the composite pole piece, the force exerted by the second rolling area on the hollow foil area is less than the force exerted by the first rolling area on the composite area.

[0009] Optionally, the pressing roller comprises:

[0010] Rigid support portion;

[0011] A first covering layer, wherein the first covering layer covers the outer periphery of the rigid support portion, and the covering thickness of the first covering layer in the second rolling zone is smaller than the covering thickness in the first rolling zone.

[0012] Optionally, the rigid support portion comprises a roller shaft and a roller core, the roller core is rigid and covers the outer circumference of the roller shaft, and the first covering layer covers the roller circumference of the roller core; or

[0013] The rigid support portion includes a roller shaft, and the first covering layer covers the outer circumference of the roller shaft.

[0014] Optionally, the first covering layer is an elastic covering layer.

[0015] Optionally, the first rolling zone includes a first elastic layer disposed along the circumferential direction, the second rolling zone includes a second elastic layer disposed along the circumferential direction, and the elasticity of the first elastic layer is smaller than the elasticity of the second elastic layer.

[0016] Optionally, the pressing roller includes a plurality of first roller pressing areas and a plurality of second roller pressing areas along the axial direction, and the first roller pressing areas and the second roller pressing areas are alternately arranged.

[0017] A rolling device comprises a supporting mechanism, a second roller and the above-mentioned pressing roller, wherein the pressing roller and the second roller are both rotatably connected to the supporting mechanism, a gap is formed between the pressing roller and the second roller, and the composite pole piece can pass through the gap between the pressing roller and the second roller.

[0018] Optionally, the second roller comprises:

[0019] a second roller shaft, the second roller shaft being rotatably connected to the support mechanism;

[0020] The second covering layer is arranged on the outer periphery of the second roller shaft, and the second covering layer is an elastic covering layer or a rigid covering layer.

[0021] Optionally, the rolling device further comprises a driving mechanism, and the driving mechanism is capable of driving the pressing roller and the second roller to rotate in opposite directions.

[0022] Optionally, the driving mechanism comprises:

[0023] A first driving source, wherein an output end of the first driving source is drivingly connected to a first end of the pressure roller;

[0024] A second driving source, wherein an output end of the second driving source is drivingly connected to a second end of the pressure roller;

[0025] The first driving source and the second driving source can respectively drive the pressing roller to rotate in opposite directions.

[0026] The beneficial effects of the utility model are:

[0027] The pressing roller of the utility model, when rolling the composite electrode sheet, the first rolling area contacts the composite area of ​​the composite electrode sheet, and the second rolling area contacts the empty foil area of ​​the composite electrode sheet. When the pressing roller rotates around its axis and rolls the composite electrode sheet, because the force exerted by the second rolling area on the empty foil area is smaller than the force exerted by the first rolling area on the composite area, the performance difference that the ductility of the empty foil area is greater than that of the composite area is compensated, thereby ensuring that the final total ductility of the empty foil area and the composite area matches, thereby avoiding wrinkles in the empty foil area.

[0028] The rolling device of the utility model, by providing the above-mentioned pressing roller, can avoid wrinkles in the empty foil area when rolling the composite pole piece, thereby ensuring that the pole ear of the battery cell manufactured from the rolled composite pole piece meets the use requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a schematic diagram of the cross-sectional structure of the composite pole piece;

[0030] Figure 2 It is a structural schematic diagram of a rolling device provided in Embodiment 1 of the present utility model;

[0031] Figure 3 This is a cross-sectional view of the first pressing roller provided in the first embodiment of the utility model;

[0032] Figure 4 It is a cross-sectional view of the second pressing roller provided in the first embodiment of the utility model;

[0033] Figure 5 It is a cross-sectional view of the third pressing roller provided in the first embodiment of the utility model;

[0034] Figure 6 It is a cross-sectional view of the fourth pressing roller provided in the first embodiment of the utility model;

[0035] Figure 7 It is a cross-sectional view of the first type of second roller provided in the first embodiment of the utility model;

[0036] Figure 8 It is a cross-sectional view of the second type of second roller provided in the first embodiment of the utility model;

[0037] Fig. 9 It is a structural schematic diagram of the rolling device provided in the second embodiment of the utility model.

[0038] In the figure:

[0039] 100, composite pole piece; 110, pole piece; 111, substrate; 112, active material layer; 120, composite layer; 130, composite area; 140, empty foil area;

[0040] 20. Pressing roller; 201. First roller pressing area; 202. Second roller pressing area; 21. Rigid support portion; 211. Roller shaft; 212. Roller core; 22. First covering layer; 23. First elastic layer; 24. Second elastic layer;

[0041] 30. second roller; 31. second roller shaft; 32. second covering layer; 33. second roller core;

[0042] 40. Support mechanism; 41. Bottom plate; 42. First support seat; 43. Second support seat;

[0043] 50. Driving mechanism; 51. First driving source; 52. Second driving source; 53. First transmission assembly; 54. Second transmission assembly; 55. Third transmission assembly; 56. Fourth transmission assembly. DETAILED DESCRIPTION

[0044] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only the parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0045] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0047] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0048] Embodiment 1

[0049] This embodiment provides a pressing roller and a rolling device, and the rolling device includes the above-mentioned pressing roller 20. The following is an introduction using the rolling device in the composite process of composite pole pieces as an example.

[0050] like Figure 1 As shown, the composite electrode 100 includes an electrode 110 and a composite layer 120. The electrode 110 includes a substrate 111 and an active material layer 112 disposed on one side of the substrate 111. The composite layer 120 is stacked on the active material layer 112. The composite layer 120 can be a solid electrolyte, a separator, a lithium supplement layer, etc. Along the width direction of the electrode 110, that is, Figure 1 In the X direction, part of the substrate 111 is not covered by the active material layer 112 and the composite layer 120, so that the composite electrode 100 has an empty foil area 140 (including only the substrate 111) and a composite area 130 (including the substrate 111, the active material layer 112 and the composite layer 120 along the thickness direction) along the width direction.

[0051] like Figure 2 As shown, the rolling device includes a support mechanism 40, a drive mechanism 50, a pressure roller 20 and a second roller 30. The pressure roller 20 and the second roller 30 are both rotatably connected to the support mechanism 40, and a gap is formed between the pressure roller 20 and the second roller 30. The drive mechanism 50 is used to drive the pressure roller 20 and the second roller 30 to rotate in opposite directions. When the rolling device is used for the composite of the electrode sheet, the drive mechanism 50 drives the pressure roller 20 and the second roller 30 to rotate in opposite directions, so that the composite electrode sheet 100 passes through the above-mentioned gap and realizes the rolling of the composite electrode sheet 100.

[0052] In this embodiment, the support mechanism 40 includes a base plate 41, a first support seat 42 and a second support seat 43. The base plate 41 is used to support on the ground, the first support seat 42 and the second support seat 43 are installed on the base plate 41 at intervals along the X direction, and the pressure roller 20 is arranged between the first support seat 42 and the second support seat 43, and the two ends are rotatably installed on the first support seat 42 and the second support seat 43 respectively. The second roller 30 is also arranged between the first support seat 42 and the second support seat 43, and the two ends are rotatably installed on the first support seat 42 and the second support seat 43 respectively. In other embodiments, the support mechanism 40 can also be provided with only the first support seat 42 and the second support seat 43. In other embodiments, the first support seat 42 and the second support seat 43 can also be provided as an integrated structure, which is not specifically limited here.

[0053] like Figure 2 As shown, the driving mechanism 50 includes a first driving source 51 and a third driving source (obstructed by other structures), wherein the output end of the first driving source 51 is transmission-connected to the first end of the pressure roller 20, and the output end of the third driving source is transmission-connected to the first end of the second roller 30, and the first driving source 51 and the third driving source can respectively drive the pressure roller 20 and the second roller 30 to rotate in the opposite direction, thereby realizing the driving and rolling of the composite pole piece 100. In this embodiment, the driving mechanism 50 also includes a first transmission assembly 53 and a third transmission assembly 55, and the first driving source 51 is transmission-connected to the first end of the pressure roller 20 through the first transmission assembly 53, and can realize driving the pressure roller 20 to rotate around its own axis. The third driving source is transmission-connected to the first end of the second roller 30 through the third transmission assembly 55, and can realize driving the second roller 30 to rotate around its own axis. Optionally, the first driving source 51 and the third driving source can both be motors. The first transmission assembly 53 and the third transmission assembly 55 can both be belt transmission structures, and the number and arrangement of the pulleys in each transmission assembly can be flexibly set as needed.

[0054] like Figure 2 As shown, the driving mechanism 50 also includes a second driving source 52 and a fourth driving source (obstructed by other structures), wherein the output end of the second driving source 52 is transmission-connected to the second end of the pressure roller 20, and the output end of the fourth driving source is transmission-connected to the second end of the second roller 30, and the second driving source 52 and the fourth driving source can respectively drive the pressure roller 20 and the second roller 30 to rotate in the opposite direction. The first driving source 51 and the second driving source 52 are respectively used to drive the pressure roller 20 to rotate in the opposite direction, and the third driving source and the fourth driving source are respectively used to drive the second roller 30 to rotate in the opposite direction. When the first driving source 51 and the third driving source are working, the pressure roller 20 and the second roller 30 can drive the composite pole piece 100 to rotate along the pressure roller 20. Figure 2 When the second driving source 52 and the fourth driving source are working, the pressure roller 20 and the second roller 30 drive the composite pole piece 100 along Figure 2The above arrangement enables the rolling device to roll the composite pole piece 100 more flexibly. In this embodiment, the second driving source 52 is connected to the second end of the pressure roller 20 through the second transmission assembly 54, and can drive the pressure roller 20 to rotate around its own axis. The fourth driving source is connected to the second end of the second roller 30 through the fourth transmission assembly 56, so as to drive the second roller 30 to rotate around its own axis. In this embodiment, the second driving source 52 and the fourth driving source can both be motors, and the second transmission assembly 54 and the fourth transmission assembly 56 can both be belt transmission structures. It should be noted that in this embodiment, a clutch is provided between the first transmission assembly 53 and the pressure roller 20, and between the second transmission assembly 54 and the pressure roller 20. When the rolling device is working, one of the first transmission assembly 53 and the second transmission assembly 54 is selected to cooperate with the pressure roller 20 for transmission, and the other is not selected to cooperate with the pressure roller 20 for transmission. Similarly, clutches are also arranged between the third transmission assembly 55 and the second roller 30, and between the fourth transmission assembly 56 and the second roller 30. When the rolling device is working, one of the third transmission assembly 55 and the fourth transmission assembly 56 is transmitted to the second roller 30, and the other one is not transmitted to the pressure roller 20.

[0055] In another embodiment, the driving mechanism 50 may also be provided with only one driving source, and the one driving source realizes reverse driving of the pressure roller 20 and the second roller 30 through a transmission structure, and the specific setting method of the transmission structure is not repeated here.

[0056] In the prior art, the pressing roller of the rolling device is a rubber roller, and the surface of the rubber roller has elastic deformation ability. Therefore, during the rolling process, the rubber roller can more fully contact with various positions of the composite electrode sheet. However, since the ductility of the empty foil area is different from that of the composite area, when the rubber roller is used for composite rolling, the elongation of the empty foil area is greater than that of the composite area, which makes it easy for wrinkles to form in the empty foil area, and further causes the quality of the electrode ears of the battery cell made of the composite electrode sheet to fail to meet the use requirements.

[0057] In this regard, Figure 2 and Figure 3 As shown, the pressing roller includes a first pressing area 201 and a second pressing area 202 along the axial direction (i.e., the X direction), the first pressing area 201 is used to press the composite area 130, and the second pressing area 202 is used to press the empty foil area 140. When the pressing roller 20 presses the composite electrode sheet 100, the side of the composite electrode sheet 100 provided with the composite layer 120 is arranged toward the pressing roller 20, and the force exerted by the second pressing area 202 on the empty foil area 140 is less than the force exerted by the first pressing area 201 on the composite area 130, thereby compensating for the performance difference that the ductility of the empty foil area 140 is greater than that of the composite area 130, ensuring that the final total ductility of the empty foil area 140 and the composite area 130 matches, thereby avoiding wrinkles in the empty foil area 140.

[0058] In this embodiment, Figure 1 As shown, the composite electrode 100 includes a composite area 130 and two empty foil areas 140 along the width direction, and the two empty foil areas 140 are respectively located at the two ends of the composite area 130 along the width direction. Figure 2 As shown, the pressing roller 20 is axially provided with a first pressing area 201 and two second pressing areas 202, and the two second pressing areas 202 are respectively located at the two ends of the first pressing area 201, thereby ensuring that the first pressing area 201 of the pressing roller 20 corresponds to the composite area 130 of the composite electrode sheet 100, and the second pressing area 202 corresponds to the empty foil area 140.

[0059] In some embodiments, Figure 3 As shown, the pressing roller 20 includes a rigid support portion 21 and a first coating layer 22, and the two ends of the rigid support portion 21 are respectively used to be rotatably mounted on the support mechanism 40, and the first coating layer 22 is an elastic coating layer, and is coated on the outer periphery of the rigid support portion 21. The provision of the rigid support portion 21 can prevent the pressing roller 20 from bending and deforming in the axial direction, and ensure that the thickness of the composite electrode sheet 100 is uniform at each position in the width direction. The coating thickness of the first coating layer 22 in the second rolling zone 202 is less than the coating thickness in the first rolling zone 201. As a result, the maximum outer diameter of the pressing roller 20 in the second rolling zone 202 is less than the maximum outer diameter of the first rolling zone 201, and then when the pressing roller 20 rotates and rolls the composite electrode sheet 100, the force of the second rolling zone 202 on the empty foil zone 140 is less than the force of the first rolling zone 201 on the composite zone 130. Optionally, the first coating layer 22 may be made of a material having elastic deformation capability such as silicone, TPE material, TPU material, PVC material, silicone, etc., which is not specifically limited here.

[0060] like Figure 3 As shown, the rigid support part 21 includes a roller shaft 211 and a roller core 212, the roller shaft 211 is used to be rotatably mounted on the support mechanism 40, the roller core 212 is rigid and covers the outer periphery of the roller shaft 211, and the first covering layer 22 covers the roller periphery of the roller core 212. By providing a rigid roller core 212, not only can the amount of the flexible first covering layer 22 be reduced, but also the structural strength of the entire pressure roller 20 is improved. Optionally, the roller core 212 can be made of steel.

[0061] In some embodiments, Figure 4 As shown, the rigid support part 21 only includes a roller shaft 211, and the roller shaft 211 is used to be rotatably mounted on the support mechanism 40, and the first coating layer 22 directly coats the outer periphery of the roller shaft 211. In this embodiment, the number of radial layers of the pressure roller 20 is small, the manufacturing process steps are small, and the production efficiency is higher. However, under the premise that the diameter of the pressure roller 20 is required to be certain, the material consumption of the first coating layer 22 increases accordingly.

[0062] In some embodiments, Figure 5 As shown, the maximum outer diameter of the first rolling zone 201 is the same as the maximum outer diameter of the second rolling zone 202, the first rolling zone 201 includes a first elastic layer 23 arranged along the circumferential direction, and the second rolling zone 202 includes a second elastic layer 24 arranged along the circumferential direction, and the elasticity of the first elastic layer 23 is less than the elasticity of the second elastic layer 24. Then, when the pressing roller 20 rotates and rolls the composite electrode sheet 100, the force of the second rolling zone 202 on the empty foil area 140 is less than the force of the first rolling zone 201 on the composite area 130. Optionally, the specific materials of the first coating layer 22 and the second coating layer 32 can also be selected from silicone, TPE material, TPU material, PVC material, and silicone, as long as the elasticity of the second coating layer 32 is greater than the elasticity of the first coating layer 22.

[0063] like Figure 5 As shown, the rigid support part 21 includes a roller shaft 211 and a roller core 212. The roller shaft 211 is used to be rotatably mounted on the support mechanism 40. The roller core 212 is rigid and is coated on the outer periphery of the roller shaft 211. The first elastic layer 23 and the second elastic layer 24 are both coated on the roller periphery of the roller core 212. By providing a rigid roller core 212, not only can the amount of the first elastic layer 23 and the second elastic layer 24 be reduced, but also the structural strength of the entire pressure roller 20 is improved. Optionally, the roller core 212 can be made of steel.

[0064] In some embodiments, such as Figure 6 As shown, the rigid support part 21 only includes a roller shaft 211, and the roller shaft 211 is used to be rotatably mounted on the support mechanism 40, and the first elastic layer 23 and the second elastic layer 24 are directly coated on the outer periphery of the roller shaft 211. In this embodiment, the number of layers in the radial direction of the pressure roller 20 is small, the manufacturing process steps are small, and the production efficiency is higher. However, under the premise that the diameter of the pressure roller 20 is required to be certain, the material consumption of the first elastic layer 23 and the second elastic layer 24 increases accordingly.

[0065] In some embodiments, such as Figure 7 As shown, the second roller 30 is only provided with a second roller shaft 31 and a second coating layer 32, wherein the second coating layer 32 is coated on the outer periphery of the second roller shaft 31. In this embodiment, the second roller shaft 31 has a small number of layers in the radial direction, and the manufacturing process is simple. In this embodiment, the second coating layer 32 can also be a rigid coating layer or a flexible coating layer, which is not specifically limited here.

[0066] In some embodiments, such as Figure 8As shown, the second roller 30 includes a second roller shaft 31, a second roller core 33 and a second covering layer 32. The two ends of the second roller shaft 31 are respectively used to be rotatably mounted on the support mechanism 40. The second roller core 33 covers the outer periphery of the second roller shaft 31. The second covering layer 32 covers the outer periphery of the second roller core 33. The second covering layer 32 is an elastic covering layer. The second roller 30 can reduce the amount of the second covering layer 32 by setting the second roller core 33.

[0067] Embodiment 2

[0068] This embodiment provides a pressing roller and a rolling device. The difference between the rolling device in this embodiment and the rolling device in the first embodiment is that the structure of the pressing roller is different, and the difference between the pressing roller in this embodiment and the pressing roller in the first embodiment is that the arrangement of the first roller pressing area and the second roller pressing area is different, as follows:

[0069] In some cases, such as Fig. 9 As shown, the composite pole piece 100 includes two or more composite areas 130 and two or more empty foil areas 140 along its width direction. In this regard, in this embodiment, the pressing roller 20 includes a plurality of first roller pressing areas 201 and a plurality of second roller pressing areas 202 along the axial direction. The first roller pressing areas 201 and the second roller pressing areas 202 are alternately arranged, so as to ensure that one first roller pressing area 201 corresponds to one composite area 130 of the composite pole piece 100, and one second roller pressing area 202 corresponds to one empty foil area 140 of the composite pole piece 100. In this embodiment, the pressing roller 20 includes three second roller pressing areas 202 and two first roller pressing areas 201. In other embodiments, the specific number of the first roller pressing area 201 and the second roller pressing area 202 can be set correspondingly according to the arrangement of the composite area 130 and the empty foil area 140 on the composite pole piece 100, and is not specifically limited here.

[0070] Obviously, the above embodiments of the utility model are only examples for clearly explaining the utility model, and are not intended to limit the implementation methods of the utility model. For ordinary technicians in the field, according to the idea of ​​the utility model, there will be changes in the specific implementation methods and application scopes, and the content of this specification should not be understood as limiting the utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the utility model should be included in the protection scope of the claims of the utility model.

Claims

1. A pressing roller for rolling a composite pole piece (100), wherein the composite pole piece (100) comprises a composite area (130) and a hollow foil area (140), characterized in that: The pressing roller comprises a first pressing area (201) and a second pressing area (202) along the axial direction, the first pressing area (201) being used for pressing the composite area (130), and the second pressing area (202) being used for pressing the empty foil area (140), and when the pressing roller presses the composite electrode sheet (100), the force exerted by the second pressing area (202) on the empty foil area (140) is smaller than the force exerted by the first pressing area (201) on the composite area (130).

2. The pressure roller according to claim 1, characterized in that The pressure roller comprises: A rigid support portion (21); A first coating layer (22), wherein the first coating layer (22) is coated on the outer periphery of the rigid support portion (21), and the coating thickness of the first coating layer (22) in the second rolling zone (202) is smaller than the coating thickness in the first rolling zone (201).

3. The pressure roller according to claim 2, characterized in that: The rigid support portion (21) comprises a roller shaft (211) and a roller core (212), the roller core (212) is rigid and covers the outer circumference of the roller shaft (211), and the first covering layer (22) covers the roller circumference of the roller core (212); or The rigid support portion (21) comprises a roller shaft (211), and the first coating layer (22) coats the outer circumference of the roller shaft (211).

4. The pressure roller according to claim 3, characterized in that: The first covering layer (22) is an elastic covering layer.

5. The pressure roller according to claim 1, characterized in that: The first rolling zone (201) includes a first elastic layer (23) arranged along the circumferential direction, and the second rolling zone (202) includes a second elastic layer (24) arranged along the circumferential direction, and the elasticity of the first elastic layer (23) is smaller than the elasticity of the second elastic layer (24).

6. The pressing roller according to any one of claims 1 to 5, characterized in that: The pressing roller comprises a plurality of first roller pressing areas (201) and a plurality of second roller pressing areas (202) along the axial direction, and the first roller pressing areas (201) and the second roller pressing areas (202) are arranged alternately.

7. A rolling device, characterized in that: It comprises a supporting mechanism (40), a second roller (30) and a pressing roller as described in any one of claims 1 to 6, wherein the pressing roller and the second roller (30) are both rotatably connected to the supporting mechanism (40), a gap is formed between the pressing roller and the second roller (30), and the composite pole piece (100) can pass through the gap between the pressing roller and the second roller (30).

8. The rolling device according to claim 7, characterized in that: The second roller (30) comprises: a second roller shaft (31), the second roller shaft (31) being rotatably connected to the support mechanism (40); A second covering layer (32), wherein the second covering layer (32) is arranged on the outer periphery of the second roller shaft (31), and the second covering layer (32) is an elastic covering layer or a rigid covering layer.

9. The rolling device according to claim 7 or 8, characterized in that: The rolling device further comprises a driving mechanism (50), wherein the driving mechanism (50) is capable of driving the pressing roller and the second roller (30) to rotate in opposite directions.

10. The rolling device according to claim 9, characterized in that: The driving mechanism (50) comprises: A first driving source (51), wherein an output end of the first driving source (51) is drivingly connected to a first end of the pressure roller; A second driving source (52), wherein an output end of the second driving source (52) is drivingly connected to a second end of the pressure roller; The first driving source (51) and the second driving source (52) can respectively drive the pressing roller to rotate in opposite directions.

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