Battery pole piece and rolling device

Abstract

The utility model relates to a battery pole piece and a rolling device, and belongs to the technical field of batteries, the battery pole piece comprises a foil piece, at least one surface of the foil piece is provided with blank areas and coating areas which are alternately arranged in the width direction of the foil piece, and the coating areas are coated with electrode slurry layers and protective slurry layers located on at least one side of the electrode slurry layers in the width direction; and a plurality of notches which penetrate through the protective slurry layer and the foil and are arranged at intervals along the length direction of the foil are formed in the battery pole piece. As the protective slurry layer coating part is provided with the plurality of notches which penetrate through the protective slurry layer and the foil and are arranged at intervals along the length direction of the foil, the notches can release stress, so that the extension of the protective slurry layer coating part is larger, and the tensile extension of the protective slurry layer coating part is ensured; and the coating part of the protective slurry layer can be matched with the stretching extension of the blank area, so that the extension of the coating part of the subsequent electrode slurry layer after rolling can be matched, and wrinkles generated by rolling can be effectively reduced.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and particularly to a battery electrode sheet and a rolling device. Background Art

[0002] Electrode sheet rolling is an essential process in the battery manufacturing process. The purpose of rolling is to obtain an electrode sheet that meets the design parameters. Electrode sheet rolling can enhance the bonding strength between the active material electrode paste and the foil, preventing the peeling of the electrode paste layer during electrolyte immersion and battery use. At the same time, electrode sheet rolling can compress the volume of the battery cell, improve the energy density of the battery cell, reduce the internal porosity of the electrode sheet, reduce the battery resistance, and improve the battery performance.

[0003] Since the foil usually uses copper foil or aluminum foil with good metal workability and ductility, during the electrode sheet rolling process, the electrode paste coated on the foil surface is extruded against each other, applying a certain pressure to the foil, causing the foil to have a certain extension. That is, the part of the foil corresponding to the electrode paste will be extended under the action of pressure, while the part without the coated electrode paste will not be extended. The extensions of the two positions are inconsistent, forming a wavy edge of the foil in appearance. In severe cases, fine wrinkles will be formed. The wrinkles may subsequently cause the diaphragm to be punctured, leading to a short circuit. The electrode paste at the wrinkled edge is also more likely to fall off, causing relatively serious quality problems.

[0004] Therefore, in the existing manufacturing method, the part without the coated electrode paste is stretched and extended in advance, and then the part with the electrode paste is rolled and extended, so that the extensions of the foil areas corresponding to the two parts are basically the same, thereby reducing the wrinkles generated by rolling. However, in order to prevent problems such as short circuits caused by burrs generated during the formation of the tab by laser cutting the electrode sheet, a protective paste layer (such as a ceramic paste layer, an organic insulating layer, a semiconductor paste layer, etc.) is coated between the electrode paste layer and the blank area on the electrode sheet. That is, the part of the electrode sheet without the coated electrode paste includes the protective paste layer and the blank area. Due to the material characteristics of the protective paste layer, the coated part of the protective paste layer is not easily extended during stretching, making it difficult to match the extension of the stretched blank area and also unable to match the extension after rolling of the part coated with the electrode paste, and thus unable to effectively reduce the wrinkles generated by rolling. Summary of the Invention

[0005] Embodiments of the present application provide a battery electrode sheet and a rolling device to solve the problem that the coated part of the protective paste layer on the electrode sheet is not easily extended during stretching and is difficult to match the stretching extension of the blank area and the rolling extension of the part coated with the electrode paste.

[0006] In a first aspect, embodiments of the present application provide a battery electrode sheet, including:

[0007] A foil, at least one surface of which has blank areas and coated areas alternately arranged along its own width direction, an electrode paste layer is coated on the coated area, and a protective paste layer is located on at least one side of the electrode paste layer along the width direction. A plurality of cuts are provided on the battery electrode sheet, penetrating through the protective paste layer and the foil and spaced along the length direction of the foil.

[0008] In a first aspect, in some embodiments, the cuts are linear and extend laterally along the protective paste layer.

[0009] In a first aspect, in some embodiments, the inclination directions of the cuts located on the same side of the electrode paste layer along the width direction are the same.

[0010] In a first aspect, in some embodiments, one end of the cut is close to the side edge of the electrode paste layer, and the other end extends to the blank area.

[0011] In a first aspect, in some embodiments, the distance between each cut and the side edge of the electrode paste layer is not less than 1 mm, and the distance between two adjacent cuts is not less than 1 mm.

[0012] In a second aspect, an embodiment of the present application provides a rolling device, including:

[0013] An unwinding mechanism, a tangent mechanism, a stretching mechanism, a rolling mechanism, and a winding mechanism arranged in sequence along the conveying direction of the battery electrode sheet;

[0014] The tangent mechanism includes a cutting head for cutting the coated part of the protective paste layer on the battery electrode sheet to form a cut penetrating through the battery electrode sheet;

[0015] The stretching mechanism includes an upper stretching roller and a lower stretching roller. The diameters of the roller sections of the upper stretching roller and the lower stretching roller that contact the blank area and the protective paste layer on the battery electrode sheet are larger than the diameters of the roller sections that contact the electrode paste layer.

[0016] The rolling mechanism includes an upper pressing roller and a lower pressing roller respectively arranged on both sides of the battery electrode sheet for rolling the electrode paste layer on the battery electrode sheet.

[0017] In a second aspect, in some embodiments, the cutting head is a laser cutting head, and the included angle formed by the moving track of the laser cutting head cutting the cut and the conveying direction of the battery electrode sheet is an obtuse angle.

[0018] In a second aspect, in some embodiments, the cutting head is a cutting blade, and the included angle formed by the cutting blade and the conveying direction of the battery electrode sheet is an obtuse angle.

[0019] In a second aspect, in some embodiments, the roller sections of the upper stretching roller and the lower stretching roller that come into contact with the blank areas and the protective slurry layer on the battery electrode sheet are surrounded and adhered with Teflon tapes.

[0020] In a second aspect, in some embodiments, a tensioning mechanism is further included between the rolling mechanism and the winding mechanism. The tensioning mechanism includes an upper tensioning roller and a lower tensioning roller, and a driving mechanism for driving the upper tensioning roller and the lower tensioning roller to approach or move away from each other.

[0021] The beneficial effects brought by the technical solutions provided in this application include:

[0022] The embodiments of this application provide a battery electrode sheet and a rolling device, including a foil, at least one surface of which has blank areas and coating areas arranged alternately along its own width direction. An electrode slurry layer and a protective slurry layer located on at least one side edge of the electrode slurry layer along the width direction are coated on the coating areas. A plurality of cuts are provided on the battery electrode sheet, which penetrate through the protective slurry layer and the foil and are arranged at intervals along the length direction of the foil.

[0023] Since a plurality of cuts that penetrate through the protective slurry layer and the foil and are arranged at intervals along the length direction of the foil are provided on the coated part of the protective slurry layer, the cuts can release stress, enabling the coated part of the protective slurry layer to have a greater extension, ensuring the stretching and extension of the coated part of the protective slurry layer, making the coated part of the protective slurry layer match the stretching and extension of the blank area, and thus also matching the rolling extension of the subsequent coated part of the electrode slurry layer, thereby effectively reducing the wrinkles generated during rolling.

[0024] In addition, the embodiments of this application also provide a rolling device. Through the unwinding mechanism and the winding mechanism, the conveying of the battery electrode sheet is realized. At the same time, in cooperation with the tangent mechanism, the protective slurry layer on the battery electrode sheet can be cut to form cuts that penetrate through the battery electrode sheet. Since the cutting head of the tangent mechanism can continuously work during the conveying of the battery electrode sheet, a plurality of cuts that penetrate through the protective slurry layer and the foil and are arranged at intervals along the length direction of the foil can be formed on the coated part of the protective slurry layer of the battery electrode sheet, so as to solve the problem that the coated part of the protective slurry layer on the electrode sheet is not easily extended during stretching and is difficult to match the stretching and extension of the blank area and the rolling extension of the coated part of the electrode slurry. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of this application, the drawings required for description in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0026] Figure 1Schematic diagram of the structure of the battery electrode sheet according to an embodiment of the present application;

[0027] Figure 2 Cross-sectional schematic diagram of the electrode paste layer according to an embodiment of the present application;

[0028] Figure 3 Schematic diagram of the implementation of the rolling device according to an embodiment of the present application;

[0029] Figure 4 Schematic diagram of the structure of the rolling device according to an embodiment of the present application;

[0030] Figure 5 Schematic diagram of the structure of the upper stretching roller according to an embodiment of the present application.

[0031] In the drawings, the list of components represented by each reference numeral is as follows:

[0032] 100, battery electrode sheet; 10, foil; 11, blank area; 12, coating area; 20, electrode paste layer; 30, protective paste layer; 40, notch;

[0033] 200, unwinding mechanism; 300, tangent mechanism; 400, stretching mechanism; 410, upper stretching roller; 420, lower stretching roller; 430, Teflon tape; 500, rolling mechanism; 510, upper pressure roller; 520, lower pressure roller; 600, winding mechanism; 700, tensioning mechanism. Detailed implementation manners

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0035] The embodiments of the present application provide a battery electrode sheet and a rolling device, which can solve the problem that the coated part of the protective paste layer on the electrode sheet is not easily extended during stretching, and it is difficult to match the stretching and extension of the blank area and the rolling and extension of the electrode paste coated part.

[0036] Refer to Figures 1 to 5 As shown, in the first aspect of the embodiments of the present application, a battery electrode sheet is provided, including:

[0037] The foil 10 has, on at least one of its surfaces, blank areas 11 and coated areas 12 that are alternately arranged along its width direction. An electrode paste layer 20 and a protective paste layer 30 located on at least one side of the electrode paste layer 20 along the width direction are coated on the coated areas 12. A plurality of cuts 40 are provided on the battery electrode sheet 100 that penetrate through the protective paste layer 30 and the foil 10 and are spaced along the length direction of the foil 10. Specifically, both surfaces of the foil 10 may have blank areas 11 and coated areas 12 that are alternately arranged along its width direction; or only one surface of the foil 10 has blank areas 11 and coated areas 12 that are alternately arranged along its width direction, and the other side is not coated and is all blank area 11; the protective paste layer may be provided only on one side of the electrode paste layer, or may be provided on both sides. There is no limit to the number of the blank areas 11 and the coated areas 12 either. It may only include one blank area 11 and one coated area 12, or two blank areas 11 and one coated area 12, or may also include multiple blank areas 11 and multiple coated areas 12, etc.

[0038] On the coated part of the protective paste layer 30 of the battery electrode sheet 100 in the embodiment of the present application, a plurality of cuts 40 are provided that penetrate through the protective paste layer 30 and the foil 10 and are spaced along the length direction of the foil 10. The cuts 40 can release stress, can make the extension of the coated part of the protective paste layer 30 larger, ensure the stretching extension of the coated part of the protective paste layer 30, so that the coated part of the protective paste layer 30 can match the stretching extension of the blank area 11, and thus can also match the rolling extension of the subsequent coated part of the electrode paste layer 20, thereby effectively reducing the wrinkles generated by rolling.

[0039] It should be noted that when the extension states of the coated part of the electrode paste layer 20, the coated part of the protective paste layer 30, and the blank area 11 are the same, it is the optimal state. In the optimal state, the whole foil 10 extends evenly and no wrinkles are generated. The purpose of providing the cuts 40 penetrating through the coated part of the protective paste layer 30 of the battery electrode sheet 100 in the present application is to increase the stretching extension of the coated part of the protective paste layer 30, that is, to ensure that after the coated part of the electrode paste layer 20 is roll-extended, the extensions of the coated part of the protective paste layer 30 and the blank area 11 match the extension of the coated part of the electrode paste layer 20, so that the extension states of the three are as close to the optimal state as possible.

[0040] It should be noted that since the components in the protective paste layer have properties such as anti-electrolyte corrosion and relative softness, coating the protective paste layer 30 on one side of the electrode paste layer 20 along the width direction can reduce the probability of burrs generated during the laser cutting of the tab, and at the same time prevent the generated burrs from piercing or scratching the separator, reducing the internal short-circuit rate of the battery and improving the safety performance of the lithium-ion battery during use. The protective paste layer is a conventional design in the art, and it can be a ceramic paste layer, an organic insulating layer, a semiconductor paste layer, etc., which will not be described in detail here.

[0041] In a first aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown, an embodiment of the present application provides a battery electrode sheet. A cut 40 of the battery electrode sheet 100 is linear and extends along the lateral direction of the protective paste layer 30.

[0042] On the protective paste layer 30 of the embodiment of the present application, a plurality of cuts 40 are provided that penetrate the foil 10 and are spaced along the length direction of the foil 10. The cuts 40 are linear and extend along the lateral direction of the protective paste layer 30. The cuts 40 extending along the lateral direction of the protective paste layer 30 means that the linear cuts 40 intersect the stretching direction of the coated part of the protective paste layer 30 (i.e., the length direction of the foil 10). Therefore, the coated part of the protective paste layer 30 can be extended more, ensuring the stretching and extension of the coated part of the protective paste layer 30, and making it easy for the stretching and extension of the coated part of the protective paste layer 30 to match the stretching and extension of the blank area 11.

[0043] In a first aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown, an embodiment of the present application provides a battery electrode sheet. The inclination directions of the cuts 40 on the same side of the electrode paste layer 20 of the battery electrode sheet 100 along the width direction are the same. Further, when cuts 40 are provided on both sides of the electrode paste layer 20, the cuts 40 on both sides are symmetrically arranged, and the inclination directions of the cuts 40 on a single side are the same.

[0044] The inclination directions of the cuts 40 on a single side of the electrode paste layer 20 in the embodiment of the present application are the same (i.e., the inclination angles of all the cuts 40 on one side of the electrode paste layer 20 relative to the length direction of the foil 10 are the same), which can reduce the risk of tape breakage during the conveying and stretching of the battery electrode sheet 100. Specifically, since the coated part of the protective paste layer 30 and the blank area 11 are stretched and extended in advance to facilitate the subsequent matching of the extension during the rolling of the coated part of the electrode paste layer 20. When stretching and extending in advance, due to the different material properties of the covering materials of the coated part of the electrode paste layer 20, the coated part of the protective paste layer 30, and the blank area 11, the stretching and extension states of the three are different. The coated part of the electrode paste layer 20 is the most difficult to stretch and extend, resulting in stretching marks near the coated part of the electrode paste layer 20 after the pre-stretching and extension. The included angle formed by the stretching marks and the conveying direction of the battery electrode sheet 100 is an obtuse angle. In this embodiment, the inclination directions of the cuts 40 on a single side of the electrode paste layer 20 are the same, which can make the cuts 40 basically extend along the direction of the stretching marks, thereby avoiding excessive intersection angles between the cuts 40 and the stretching marks and causing stretching and tearing of the tape.

[0045] In a first aspect, in some alternative embodiments: Refer to Figures 1 to 5As shown in the figure, an embodiment of the present application provides a battery electrode sheet. One end of the cut 40 of the battery electrode sheet 100 is close to the side edge of the electrode paste layer 20, and the other end extends to the blank area 11.

[0046] One end of the cut 40 in the embodiment of the present application is close to the side edge of the electrode paste layer 20, which can make the coated area of the protective paste layer 30 extend as large as possible without damaging the electrode paste layer 20, ensuring the stretching and extension of the coated area of the protective paste layer 30. In addition, the other end of the cut 40 extends to the blank area 11, which can reduce the processing difficulty of the cut 40 and further ensure that the coated area of the protective paste layer 30 is easy to stretch and extend.

[0047] In a first aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown in the figure, an embodiment of the present application provides a battery electrode sheet. The distance between each cut 40 of the battery electrode sheet 100 and the side edge of the electrode paste layer 20 is not less than 1 mm, and the distance between two adjacent cuts 40 is not less than 1 mm.

[0048] The distance between the cut 40 in the embodiment of the present application and the side edge of the electrode paste layer 20 is not less than 1 mm, which can prevent the end of the cut 40 from being too close to the electrode paste layer 20 and causing tearing and expansion during stretching and extension, thereby damaging the electrode paste layer 20. The distance between two adjacent cuts 40 is not less than 1 mm, which can prevent two adjacent cuts 40 from being too close and causing a break between the cuts 40.

[0049] Refer to Figures 1 to 5 As shown in the figure, a second aspect of the embodiment of the present application provides a rolling device, including:

[0050] An unwinding mechanism 200, a cutting mechanism 300, a stretching mechanism 400, a rolling mechanism 500, and a winding mechanism 600 arranged in sequence along the conveying direction of the battery electrode sheet 100;

[0051] The cutting mechanism 300 includes a cutting head for cutting the coated area of the protective paste layer 30 on the battery electrode sheet 100 to form a cut 40 penetrating the battery electrode sheet 100;

[0052] The stretching mechanism 400 includes an upper stretching roller 410 and a lower stretching roller 420. The diameters of the roller sections of the upper stretching roller 410 and the lower stretching roller 420 that contact the blank area 11 and the protective paste layer 30 on the battery electrode sheet 100 are larger than the diameters of the roller sections that contact the electrode paste layer 20;

[0053] The rolling mechanism 500 includes an upper pressing roller 510 and a lower pressing roller 520 respectively arranged on both sides of the battery electrode sheet 100 for rolling the electrode paste layer 20 on the battery electrode sheet 100.

[0054] The rolling device according to the embodiment of the present application realizes the conveyance of the battery electrode sheet 100 through the unwinding mechanism 200 and the winding mechanism 600. Meanwhile, in cooperation with the tangent mechanism 300, the coating part of the protective slurry layer 30 on the battery electrode sheet 100 can be cut to form a cut 40 penetrating the battery electrode sheet 100. Since the cutting head of the tangent mechanism 300 can continuously work during the conveyance of the battery electrode sheet 100, several cuts 40 penetrating the protective slurry layer 30 and the foil 10 and spaced along the length direction of the foil 10 can be formed on the coating part of the protective slurry layer 30 of the battery electrode sheet 100. The related effects of the cut 40 have been described in the above embodiments, so they will not be elaborated here.

[0055] In addition, since the diameters of the upper stretching roller 410 and the lower stretching roller 420 of the stretching mechanism 400 in contact with the blank area 11 and the roller section of the protective slurry layer 30 on the battery electrode sheet 100 are larger than the diameters of the roller sections in contact with the electrode slurry layer 20, the upper stretching roller 410 and the lower stretching roller 420 can be used in cooperation to stretch and extend the coating part of the protective slurry layer 30 and the blank area 11 in advance, so as to facilitate the rolling and extension of the subsequent coating part of the electrode slurry layer 20. Specifically, when there is a coating area 12 on only one side of the foil 10, only one stretching roller (one of the upper stretching roller 410 or the lower stretching roller 420) that will contact the coating area 12 has roller sections with different diameters, and the other stretching roller (the other of the upper stretching roller 410 or the lower stretching roller 420) that does not contact the coating area 12 has the same diameter; if there are coating areas 12 on both sides of the foil 10, both the upper stretching roller 410 and the lower stretching roller 420 have roller sections with different diameters.

[0056] Exemplarily, both the unwinding mechanism 200 and the winding mechanism 600 are winding machines, and the tangent mechanism 300 is a laser cutting machine with multiple laser cutting heads. The laser cutting machine can drive the multiple laser cutting heads to move to continuously process the cut 40 on the conveyed battery electrode sheet 100.

[0057] The stretching mechanism 400 further includes a first working cylinder of pneumatic or hydraulic pressure for driving the upper stretching roller 410 and the lower stretching roller 420 to approach or move away from each other. The first working cylinder can be used to drive the upper stretching roller 410 and the lower stretching roller 420 to move, and the roller sections with different diameters on the upper stretching roller 410 and the lower stretching roller 420 are used to stretch and extend the coating part of the protective slurry layer 30 and the blank area 11.

[0058] The rolling mechanism 500 further includes a second working cylinder of pneumatic or hydraulic pressure for driving the upper pressing roller 510 and the lower pressing roller 520 to approach or move away from each other, so as to adjust the rolling spacing of the battery electrode sheet 100, and facilitate the rolling and extension of the subsequent coating part of the electrode slurry layer 20 to match the extension of the coating part of the protective slurry layer 30 and the blank area 11.

[0059] Second aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown, an embodiment of the present application provides a rolling device, the cutting head of the rolling device is a laser cutting head, and the included angle formed by the moving track of the laser cutting head cutting the cut 40 and the conveying direction of the battery electrode sheet 100 is an obtuse angle.

[0060] The cutting head of the embodiment of the present application is a laser cutting head, that is, the tangent mechanism 300 is a laser cutting machine with a plurality of laser cutting heads. The laser cutting machine can drive the plurality of laser cutting heads to move to continuously process the cut 40 on the conveyed battery electrode sheet 100.

[0061] And the included angle formed by the moving track of the laser cutting head cutting the cut 40 and the conveying direction of the battery electrode sheet 100 is an obtuse angle, which can make the processed cut 40 extend basically along the direction of the stretching lines, thereby avoiding the stretching and tearing of the belt due to the excessive intersection angle between the cut 40 and the stretching lines. It should be noted that the reason for the generation of the stretching lines has been described in the above embodiments, so it will not be repeated here.

[0062] Second aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown, an embodiment of the present application provides a rolling device, the cutting head of the rolling device is a cutting blade, and the included angle formed by the cutting blade and the conveying direction of the battery electrode sheet 100 is an obtuse angle. Wherein, the included angle formed by the cutting blade and the conveying direction of the battery electrode sheet 100 refers to the included angle formed by the direction in which the cutting blade extends from the side close to the electrode paste layer 20 to the side far from the electrode paste layer 20 and the conveying direction of the battery electrode sheet 100.

[0063] The cutting head of the embodiment of the present application is a cutting blade, and the included angle formed by the cutting blade and the conveying direction of the battery electrode sheet 100 is an obtuse angle. Exemplarily, the cutting blades can be installed around and at intervals on the roller, and the cut 40 can be continuously processed on the conveyed battery electrode sheet 100 by rolling.

[0064] And the included angle formed by the cutting blade and the conveying direction of the battery electrode sheet 100 is an obtuse angle, which can make the processed cut 40 extend basically along the direction of the stretching lines, thereby avoiding the stretching and tearing of the belt due to the excessive intersection angle between the cut 40 and the stretching lines. It should be noted that the reason for the generation of the stretching lines has been described in the above embodiments, so it will not be repeated here.

[0065] Second aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown, an embodiment of the present application provides a rolling device, and the roller sections of the upper stretching roller 410 and the lower stretching roller 420 of the rolling device that are used to contact the blank area 11 and the protective paste layer 30 on the battery electrode sheet 100 are surrounded and adhered with Teflon tapes 430.

[0066] In the embodiment of the present application, Teflon tapes 430 are wound around the upper stretching roller 410 and the lower stretching roller 420. The roller sections without the Teflon tapes 430 adhered are in contact with the electrode paste layer 20, and the roller sections with the Teflon tapes 430 adhered are in contact with the blank area 11 and the protective paste layer 30. However, the diameters of the roller sections at the winding and pasting positions of the Teflon tapes 430 will become larger, which easily contact the blank area 11 and the protective paste layer 30 on the battery electrode sheet 100, and then stretch and extend the blank area 11 and the protective paste layer 30.

[0067] In a second aspect, in some alternative embodiments: Refer to Figures 1 to 5 As shown, the embodiment of the present application provides a rolling device, which further includes a tensioning mechanism 700 disposed between the rolling mechanism 500 and the winding mechanism 600. The tensioning mechanism 700 includes an upper tensioning roller and a lower tensioning roller, and a driving mechanism for driving the upper tensioning roller and the lower tensioning roller to approach or separate from each other.

[0068] The tensioning mechanism 700 of the embodiment of the present application is disposed between the rolling mechanism 500 and the winding mechanism 600, which can tension the battery electrode sheet 100, stabilize the conveying state of the battery electrode sheet 100, and ensure the tightness after winding by the winding mechanism 600. Exemplarily, the driving mechanism can be a pneumatic or hydraulic working cylinder. The battery electrode sheet 100 sequentially bypasses the upper tensioning roller and the lower tensioning roller, and the working cylinder can be used to drive the upper tensioning roller and the lower tensioning roller to approach or separate from each other, so as to adjust the tension of the battery electrode sheet 100.

[0069] In the description of the present application, it should be noted that the orientation or positional relationship indicated by terms such as "upper" and "lower" is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application 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 to the present application. Unless otherwise clearly specified and defined, the terms "installation", "connection", and "connection" 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, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0070] It should be noted that in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising said element.

[0071] The above are only specific embodiments of the present application, enabling those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. A battery pole piece, characterized in that: include: A foil (10) having at least one surface with blank areas (11) and coating areas (12) arranged alternately along its width direction, the coating area (12) being coated with an electrode slurry layer (20) and a protective slurry layer (30) located on at least one side of the electrode slurry layer (20) along the width direction, and the battery electrode (100) being provided with a plurality of cuts (40) penetrating the protective slurry layer (30) and the foil (10) and being arranged at intervals along the length direction of the foil (10).

2. The battery pole piece according to claim 1, characterized in that: The cutout (40) is linear and extends along the side of the protective slurry layer (30).

3. The battery pole piece according to claim 1, characterized in that: The inclination directions of the cutouts (40) located on the same side of the electrode slurry layer (20) along the width direction are consistent.

4. The battery pole piece according to claim 1, characterized in that: One end of the cutout (40) is close to the side edge of the electrode slurry layer (20), and the other end extends to the blank area (11).

5. The battery pole piece according to claim 1, characterized in that: The distance between each of the cutouts (40) and the side edge of the electrode slurry layer (20) is not less than 1 millimeter, and the distance between two adjacent cutouts (40) is not less than 1 millimeter.

6. A rolling device, characterized in that: include: An unwinding mechanism (200), a cutting mechanism (300), a stretching mechanism (400), a rolling mechanism (500) and a winding mechanism (600) are sequentially arranged along the conveying direction of the battery pole piece (100); The cutting mechanism (300) comprises a cutting head for cutting a coating portion of the protective slurry layer (30) on the battery pole piece (100) to form a cut (40) penetrating the battery pole piece (100); The stretching mechanism (400) comprises an upper stretching roller (410) and a lower stretching roller (420), wherein the diameter of the roller sections on the upper stretching roller (410) and the lower stretching roller (420) contacting the blank area (11) and the protective slurry layer (30) on the battery electrode sheet (100) is greater than the diameter of the roller section contacting the electrode slurry layer (20); The rolling mechanism (500) comprises an upper pressing roller (510) and a lower pressing roller (520) which are respectively arranged on both sides of the battery electrode sheet (100) to roll the electrode slurry layer (20) on the battery electrode sheet (100).

7. The rolling device according to claim 6, characterized in that: The cutting head is a laser cutting head, and the angle formed by the moving track of the laser cutting head for cutting the incision (40) and the conveying direction of the battery electrode sheet (100) is an obtuse angle.

8. The rolling device according to claim 6, characterized in that: The cutting head is a cutting blade, and the angle formed by the cutting blade and the conveying direction of the battery electrode sheet (100) is an obtuse angle.

9. The rolling device according to claim 6, characterized in that: Teflon tape (430) is adhered around the roller sections of the upper stretching roller (410) and the lower stretching roller (420) for contacting the blank area (11) and the protective slurry layer (30) on the battery electrode sheet (100).

10. The rolling device according to claim 6, characterized in that: It also includes a tensioning mechanism (700) disposed between the rolling mechanism (500) and the winding mechanism (600), wherein the tensioning mechanism (700) includes an upper tensioning roller and a lower tensioning roller, and a driving mechanism for driving the upper tensioning roller and the lower tensioning roller to move closer to or away from each other.

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