Foil stretching device and pole piece rolling system

Abstract

The utility model discloses a foil stretching device and a pole piece rolling system. The foil stretching device is used for stretching a foil area of a battery pole piece and comprises a driving roller, and the battery pole piece is wound around the driving roller and is driven by the driving roller to be conveyed in the preset direction; the at least two unpowered wheels are arranged on one side of the driving roller and are arranged at intervals in the axial direction of the driving roller, and the unpowered wheels tightly press the foil material area on the driving roller; the at least two power wheels are arranged on the other side of the driving roller and are arranged at intervals in the axial direction of the driving roller, and the foil material area is tightly pressed on the driving roller by the power wheels; wherein the driving roller and the power wheel can respectively and actively rotate and have a linear speed difference, so that the foil area is extended and stretched. The foil stretching device disclosed by the utility model is used for stretching the foil area of the battery pole piece, and the extension of the foil area is kept consistent with that of a coating area.

Description

Technical Field

[0001] The utility model relates to the field of battery manufacturing, in particular to a foil stretching device and a pole piece rolling system. Background Art

[0002] During the battery manufacturing process, the battery pole pieces need to be rolled to increase the compaction density of the pole pieces, thereby increasing the energy density of the battery. The battery pole pieces include a coating area coated with active materials and a foil area not coated with active materials, which are arranged alternately along the lateral direction. During the rolling process of the pole piece, the coating area is extended under the action of the roller pressure, while the foil area is not affected by the roller pressure and does not extend. The extension of the coating area and the foil area is inconsistent, resulting in wavy wrinkles at the edge of the pole piece. This phenomenon is called the wavy edge of the pole piece in the battery manufacturing field. The existence of the wavy edge will have an adverse effect on the laser die-cutting process. In severe cases, the ups and downs of the wavy edge will cause the laser die-cutting equipment to defocus the laser, resulting in the inability to cut the pole piece.

[0003] In order to prevent the wavy edge from having an adverse effect on subsequent processes, the prior art manually sticks a layer of tape on the pressing roller during the rolling process, and controls the thickness of the tape by controlling the number of turns of the tape, thereby balancing the extension difference between the coating area and the foil area. However, the manual tape sticking method is complicated to operate, requires repeated debugging, and is affected by human subjective factors, and the control effect on the wavy edge is not ideal.

[0004] Therefore, how to keep the extension of the foil area and the coating area consistent is a technical problem that needs to be solved urgently. Utility Model Content

[0005] The utility model provides a foil stretching device and a pole piece rolling system, which stretch the foil area of ​​a battery pole piece that has undergone a rolling process, and keep the foil area and the coating area extending in a consistent manner.

[0006] In the first aspect, an embodiment of the utility model provides a foil stretching device for stretching the foil area of ​​a battery electrode sheet, the foil stretching device comprising: a driving roller, the battery electrode sheet is wound around the driving roller and is transmitted along a preset direction under the drive of the driving roller; at least two unpowered wheels are arranged on one side of the driving roller and are spaced apart along the axial direction of the driving roller, the unpowered wheels press the foil area tightly against the driving roller; at least two powered wheels are arranged on the other side of the driving roller and are spaced apart along the axial direction of the driving roller, the powered wheels press the foil area tightly against the driving roller; wherein the driving roller and the powered wheels can respectively rotate actively and have a linear speed difference, so that the foil area is extended and stretched.

[0007] According to the aforementioned implementation of the first aspect of the utility model, the rotation direction of the powered wheel is opposite to that of the driving roller and the linear speed is greater than that of the driving roller.

[0008] According to the aforementioned embodiment of the first aspect of the utility model, the foil stretching device also includes: a first pressure sensor, which is arranged on the driving roller at a position corresponding to the winding position of the coating area of ​​the battery electrode, and can obtain the pressure of the coating area on the outer surface of the driving roller; a second pressure sensor, which is arranged on the driving roller at a position corresponding to the winding position of the foil area, and can obtain the pressure of the foil area on the outer surface of the driving roller.

[0009] According to the aforementioned embodiment of the first aspect of the utility model, the foil stretching device also includes: a monitoring component, which can obtain the tension of the foil area relative to the coating area based on the pressure obtained by the first pressure sensor and the second pressure sensor, and compare the tension with a preset value. When the tension exceeds the preset value, it prompts to adjust the linear speed difference between the powered wheel and the driving roller.

[0010] According to the aforementioned implementation of the first aspect of the utility model, the foil stretching device further comprises: a driving roller motor, which is transmission-connected to the driving roller and is used to drive the driving roller to rotate.

[0011] According to the aforementioned embodiment of the first aspect of the utility model, the foil stretching device also includes: a first rotating shaft, and the at least two powered wheels are coaxially fixed on the first rotating shaft; a powered wheel motor, which is transmission-connected to the first rotating shaft, and the powered wheel motor simultaneously drives the at least two powered wheels to rotate through the first rotating shaft.

[0012] According to the aforementioned implementation of the first aspect of the utility model, the foil stretching device also includes: powered wheel motors matching the number of the powered wheels, each of the powered wheel motors being transmission-connected to a corresponding powered wheel to drive the corresponding powered wheel to rotate.

[0013] According to the aforementioned implementation of the first aspect of the utility model, the foil stretching device further includes: a second rotating shaft, and the at least two non-powered wheels are coaxially fixed on the second rotating shaft.

[0014] According to the aforementioned implementation of the first aspect of the utility model, the width of the powered wheel is less than or equal to the width of the foil area, and the width of the unpowered wheel is less than or equal to the width of the foil area.

[0015] In a second aspect, an embodiment of the present invention further provides a pole piece rolling system, comprising a foil stretching device according to any of the aforementioned embodiments of the first aspect of the present invention.

[0016] According to the foil stretching device of the embodiment of the utility model, the foil stretching device includes: a driving roller, at least two unpowered wheels, and at least two powered wheels. The battery pole piece is wound around the driving roller and is transmitted along a preset direction driven by the driving roller; at least two unpowered wheels are arranged on one side of the driving roller and are spaced apart along the axial direction of the driving roller, and the unpowered wheels press the foil area tightly against the driving roller; at least two powered wheels are arranged on the other side of the driving roller and are spaced apart along the axial direction of the driving roller, and the powered wheels press the foil area tightly against the driving roller; wherein the driving roller and the powered wheels can respectively actively rotate and have a linear speed difference, so that the foil area is stretched and stretched. The foil stretching device of the embodiment of the utility model stretches the foil area of ​​the battery pole piece that has undergone the rolling process, and keeps the extension of the foil area consistent with that of the coating area. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0018] Figure 1 It is a schematic structural diagram of a battery pole piece in an embodiment of the foil stretching device of the utility model;

[0019] Figure 2 It is a three-dimensional schematic diagram of an embodiment of the foil stretching device of the utility model;

[0020] Figure 3 It is a three-dimensional schematic diagram of a driving roller in an embodiment of the foil stretching device of the utility model;

[0021] Figure 4 It is a three-dimensional schematic diagram of an embodiment of the foil stretching device of the utility model;

[0022] Figure 5 It is a top view schematic diagram of an embodiment of the foil stretching device of the utility model;

[0023] Figure 6 It is a top view schematic diagram of an embodiment of the foil stretching device of the utility model;

[0024] Figure 7 It is a side view schematic diagram of an embodiment of the foil stretching device of the utility model.

[0025] Description of reference numerals:

[0026] 100-battery pole piece;

[0027] 110- coating area; 120- foil area;

[0028] 210 - driving roller; 220 - non-powered wheel; 230 - powered wheel; 240 - first pressure sensor; 250 - second pressure sensor; 260 - driving roller motor; 270 - first rotating shaft; 280 - powered wheel motor.

[0029] The realization of the purpose, functional features and advantages of the utility model will be further explained in conjunction with the embodiments with reference to the accompanying drawings. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0031] It should be noted that all directional indications such as up, down, left, right, front, back... in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture as shown in the accompanying drawings. If the specific posture changes, the directional indication will also change accordingly.

[0032] In addition, the descriptions of "first", "second", etc. in the present utility model are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present utility model.

[0033] See also Figure 1 , Figure 2 , Figure 1 This is a schematic diagram of the structure of a battery electrode 100 in an embodiment of the foil stretching device of the utility model. Figure 2 The figure is a three-dimensional schematic diagram of an embodiment of the foil stretching device of the utility model. The foil stretching device is used to stretch the foil area 120 of the battery pole piece 100. The battery pole piece 100 includes a foil area 120 and a coating area 110 alternately arranged along its transverse direction, the coating area 110 is coated with an active material, the foil area 120 is not coated with an active material, and the thickness of the coating area 110 is greater than the thickness of the foil area 120.

[0034] The foil stretching device includes a driving roller 210, at least two unpowered wheels 220, and at least two powered wheels 230. The driving roller 210 has a certain length in the axial direction and can rotate around its own central axis. The unpowered wheel 220 is arranged on one side of the driving roller 210 and is arranged at intervals along the axial direction of the driving roller 210. The spacing between two adjacent unpowered wheels 220 is equal to the lateral width of the coating area 110 on the battery pole piece 100. The unpowered wheel 220 presses the foil area 120 against the driving roller 210 to prevent the battery pole piece 100 from slipping and displacing on the driving roller 210. The driving roller 210 pulls the battery pole piece 100 in a preset direction. The powered wheel 230 can rotate around its own central axis, and the powered wheel 230 presses the foil area 120 against the driving roller 210. The powered wheel 230 and the driving roller 210 can respectively rotate actively and have a linear speed difference.

[0035] In the above embodiment, the foil area 120 of the battery electrode sheet 100 is differentially rolled by the linear speed difference between the powered wheel 230 and the driving roller 210 , so as to ensure that the extension of the foil area 120 and the coating area 110 are consistent.

[0036] In some embodiments, the rotation direction of the powered wheel 230 is opposite to that of the driving roller 210 and the linear speed is greater than that of the driving roller 210. For example, if the driving roller 210 rotates clockwise along its own central axis, the powered wheel 230 rotates counterclockwise along its own central axis. The linear speed of the powered wheel 230 is greater than the linear speed of the driving roller 210, so that part of the battery electrode sheet 100 is tightly wound on the driving roller 210, and the powered wheel 230 is in close contact with the foil area 120 of the battery electrode sheet 100. The powered wheel 230 provides a friction force to transport the battery electrode sheet 100 in a preset direction, and is used to stretch the foil area 120 of the battery electrode sheet 100.

[0037] In the above embodiment, the foil stretching device is provided with a powered wheel 230 whose linear speed is greater than the driving roller 210, and can stretch the foil area 120 of the battery electrode 100 after the rolling process to keep the extension of the foil area 120 consistent with that of the coating area 110; it replaces the method of manually sticking tape to balance the extension difference between the foil area 120 and the coating area 110 in the prior art, reduces labor costs, and has a better control effect on the extension of the foil area 120; the foil stretching device has a simple structure, a small number of parts, a low production cost, and is easy to assemble, disassemble and operate; when the battery electrode 100 changes its version, it only needs to adjust the number and spacing of the powered wheels 230 and the unpowered wheels 220, and has better compatibility.

[0038] In some embodiments, see Figure 5 , Figure 5This is a top view of an embodiment of the foil stretching device of the utility model, and the foil stretching device also includes: a first pressure sensor 240 and a second pressure sensor 250. The first pressure sensor is arranged on the driving roller 210 corresponding to the winding position of the coating area 110 of the battery electrode 100, and can obtain the pressure of the coating area 110 on the outer surface of the driving roller 210, and the second pressure sensor 250 is arranged on the driving roller 210 corresponding to the winding position of the foil area 120, and can obtain the pressure of the foil area 120 on the outer surface of the driving roller 210.

[0039] The pressure of the foil area 120 on the outer surface of the driving roller 210 is provided by the friction force of the powered wheel 230 on the foil area 120. The foil area 120 is a part of the battery electrode 100. Therefore, the friction force of the powered wheel 230 on the foil area 120 will also cause the coating area 110 in the adjacent area of ​​the battery electrode 100 to apply a pressure on the outer surface of the driving roller 210. Since the extension of the coating area 110 and the foil area 120 are inconsistent, the extension of the foil area 120 is smaller than that of the coating area 110, and the length of the foil area 120 wound on the driving roller 210 is smaller than the length of the coating area 110 wound on the driving roller 210. Therefore, the pressure applied by the coating area 110 on the outer surface of the driving roller 210 is smaller than the pressure applied by the foil area 120 on the outer surface of the driving roller 210. The friction force of the powered wheel 230 on the foil area 120 is also the tension on the foil area 120, and the tension on the coating area 110 is also provided by the friction force of the powered wheel 230 on the foil area 120. Therefore, by obtaining the pressure on the winding parts of the coating area 110 and the foil area 120 on the driving roller 210, the tension information on the coating area 110 and the tension information on the foil area 120 can be indirectly obtained. It should be noted that the tension information is not the absolute tension value on the coating area 110 or the foil area 120, but it can reflect the magnitude of the tension on the coating area 110 or the foil area 120.

[0040] In the above embodiment, the first pressure sensor 240 and the second pressure sensor 250 are arranged on the driving roller 210 to obtain the pressure of the coating area 110 and the foil area 120 on the outer surface of the driving roller 210 respectively, and then the linear velocity difference between the powered wheel 230 and the driving roller 210 can be adjusted according to these pressure data. For example, if the pressure data obtained by the second pressure sensor 250 is greater than the first pressure sensor 240, the tension of the foil area 120 is greater than the tension of the coating area 110, and the extension of the foil area 120 is less than the extension of the coating area 110, the rotation speed of the driving roller 210 can be kept unchanged, the rotation speed of the powered wheel 230 can be increased, and then the linear velocity of the powered wheel 230 can be increased, and the foil area 120 can be further stretched. For another example, if the pressure data obtained by the second pressure sensor 250 is equal to the pressure data of the first pressure sensor 240, the tension on the foil area 120 is equal to the tension on the coating area 110, and the foil area 120 and the coating area 110 extend in the same manner, and the rotation speed of the powered wheel 230 and the driving roller 210 does not change.

[0041] In some embodiments, the foil stretching device further includes a monitoring component (not shown). The monitoring component can obtain the tension of the foil area 120 relative to the coating area 110 based on the pressure values ​​obtained by the first pressure sensor 240 and the second pressure sensor 250, and compare the tension with a preset value. When the tension exceeds the preset value, it prompts to adjust the linear speed difference between the powered wheel 230 and the driving roller 210. For example, the monitoring component is electrically connected or communicatively connected to the first pressure sensor 240 and the second pressure sensor 250 to obtain pressure data obtained by the first pressure sensor 240 and the second pressure sensor 250. The pressure difference between the second pressure sensor 250 and the first pressure sensor 240 is the tension of the foil area 120 relative to the coating area 110. When the difference exceeds a preset value, a prompt is issued to adjust the linear speed difference between the powered wheel 230 and the driving roller 210. After seeing the prompt, the operator can keep the rotation speed of the driving roller 210 unchanged and increase the rotation speed of the powered wheel 230 so that the linear speed of the powered wheel 230 is greater than the linear speed of the driving roller 210, thereby further stretching the foil area 120.

[0042] In some embodiments, see Figure 3 , Figure 3 2 is a three-dimensional schematic diagram of a driving roller 210 in an embodiment of the foil stretching device of the utility model, and the foil stretching device further includes a driving roller motor 260, which is transmission-connected to the driving roller 210 and is used to drive the driving roller 210 to rotate. In some other embodiments, other driving members may also be used to drive the driving roller 210 to rotate.

[0043] In some embodiments, see Figure 2 , Figure 2This is a three-dimensional schematic diagram of an embodiment of the foil stretching device of the utility model, and the foil stretching device also includes a first rotating shaft 270 and a powered wheel motor 280. At least two powered wheels 230 are coaxially fixed on the first rotating shaft 270, and the powered wheel motor 280 is connected to the first rotating shaft 270 for driving the first rotating shaft 270 to rotate, thereby driving at least two powered wheels 230 to rotate simultaneously. In some other embodiments, other driving members may also be used to drive the first rotating shaft 270 to rotate.

[0044] In some embodiments, see Figure 4 , Figure 5 , Figure 6 , Figure 4 This is a three-dimensional schematic diagram of an embodiment of the foil stretching device of the utility model. Figure 5 This is a top view of an embodiment of the foil stretching device of the utility model. Figure 6 This is a top view of an embodiment of the foil stretching device of the utility model, and the foil stretching device further includes powered wheel motors 280 matching the number of powered wheels 230, and each powered wheel motor 280 is connected to a corresponding powered wheel 230 for driving the powered wheels 230 to rotate. The difference from the above embodiment is that the rotation speed of any powered wheel 230 can be adjusted separately, thereby adjusting the linear speed difference with the driving roller 210, and then adjusting the tension of the foil area 120 in any area, and the extension control of the foil area 120 is more precise.

[0045] In some embodiments, see Figure 7 , Figure 7 This is a side view of an embodiment of the foil stretching device of the utility model, in which the diameters of the powered wheel 230 and the unpowered wheel 220 are the same. Using wheels of the same specification can reduce the design cost of the product and make assembly more convenient.

[0046] In some embodiments, the width of the powered wheel 230 in the foil stretching device is less than or equal to the width of the foil area 120, and the width of the unpowered wheel 220 is less than or equal to the width of the foil area 120. The powered wheel 230 and the unpowered wheel 220 are prevented from damaging the coating area.

[0047] In some embodiments, the foil stretching device further includes a second rotating shaft, and at least two unpowered wheels 220 are coaxially fixed on the second rotating shaft to achieve synchronous rotation of at least two unpowered wheels 220. Compared with the isolated design of the unpowered wheels 220, the number of parts is reduced and the installation time is saved.

[0048] An embodiment of the utility model further provides a pole piece rolling system, which includes a foil stretching device according to any of the aforementioned embodiments.

[0049] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A foil stretching device for stretching the foil area of ​​a battery electrode, characterized in that: The foil stretching device comprises: A driving roller, the battery pole piece is wound around the driving roller and is driven by the driving roller to be transported along a preset direction; At least two unpowered wheels are arranged on one side of the driving roller and spaced apart along the axial direction of the driving roller, and the unpowered wheels press the foil area tightly against the driving roller; at least two powered wheels, arranged on the other side of the driving roller and spaced apart along the axial direction of the driving roller, the powered wheels pressing the foil area against the driving roller; The driving roller and the powered wheel can respectively rotate actively and have a linear speed difference, so that the foil area is extended and stretched.

2. The foil stretching device according to claim 1, characterized in that: The rotation direction of the powered wheel is opposite to that of the driving roller and the linear speed is greater than that of the driving roller.

3. The foil stretching device according to claim 1, characterized in that: The foil stretching device also includes: A first pressure sensor is disposed on the driving roller at a location corresponding to the winding of the coating area of ​​the battery electrode sheet, and is capable of obtaining the pressure of the coating area on the outer surface of the driving roller; The second pressure sensor is arranged on the driving roller at a position corresponding to the winding position of the foil area, and can obtain the pressure of the foil area on the outer surface of the driving roller.

4. The foil stretching device according to claim 3, characterized in that: The foil stretching device also includes: A monitoring component, wherein the monitoring component can obtain the tension of the foil area relative to the coating area based on the pressure obtained by the first pressure sensor and the second pressure sensor, and compare the tension with a preset value, and when the tension exceeds the preset value, it is prompted to adjust the linear speed difference between the powered wheel and the driving roller.

5. The foil stretching device according to claim 1, characterized in that: The foil stretching device also includes: The driving roller motor is drivingly connected to the driving roller and is used to drive the driving roller to rotate.

6. The foil stretching device according to claim 5, characterized in that The foil stretching device also includes: A first rotating shaft, wherein the at least two powered wheels are coaxially fixed on the first rotating shaft; The powered wheel motor is drivingly connected to the first rotating shaft, and the powered wheel motor drives the at least two powered wheels to rotate simultaneously through the first rotating shaft.

7. The foil stretching device according to claim 5, characterized in that The foil stretching device also includes: There are powered wheel motors matching the number of the powered wheels, and each powered wheel motor is drivingly connected to a corresponding powered wheel to drive the corresponding powered wheel to rotate.

8. The foil stretching device according to claim 1, characterized in that: The foil stretching device also includes: A second rotating shaft, wherein the at least two non-powered wheels are coaxially fixed on the second rotating shaft.

9. The foil stretching device according to claim 1, characterized in that: The width of the powered wheel is less than or equal to the width of the foil material area, and the width of the unpowered wheel is less than or equal to the width of the foil material area.

10. A pole piece rolling system, characterized in that: The invention comprises a foil stretching device as claimed in any one of claims 1 to 9.

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