Battery pole piece passing roller and rolling mill

Abstract

The utility model relates to battery manufacturing technical field, specifically disclose battery pole piece passes roller and roller press, this battery pole piece passes roller includes roller main part and annular boss, is provided with first area and second area for being opposite with the blank area of battery pole piece for being opposite with the coating area of battery pole piece on roller main part, first area and second area are sequentially arranged along the axial direction of roller main part, annular boss sets up in roller main part and is located first area, first area is provided with at least one annular boss. Since battery pole piece passes roller and protrudes in first area and has annular boss, annular boss lifts the coating area, and then the stress concentration area is transferred from the junction of blank area and coating area to first area, since the hardness of the coating area corresponding to first area is relatively greater than blank area, therefore, it is not easy to produce the wrinkle. Further improve the appearance quality of battery pole piece, avoid damaging the integrity of the internal structure of battery pole piece, avoid the adverse effect on subsequent battery assembly process and final product performance.

Description

Technical Field

[0001] This utility model relates to the field of battery manufacturing technology, and in particular to battery electrode rolling mill and roller press. Background Technology

[0002] The manufacturing process of lithium battery electrode sheets mainly includes: mixing raw materials such as active materials, binders and conductive agents in a specific weight ratio to prepare a uniform slurry, then uniformly coating the slurry on the surface of aluminum foil or copper foil current collector as required, pressing it into an electrode film of the target thickness by a rolling equipment, and then drying it to form a battery electrode sheet.

[0003] In the above process flow, rolling is the core compaction process in the manufacturing of lithium battery electrodes. Its mechanism of action is mainly reflected in two aspects: on the one hand, by compressing the thickness of the battery electrode, it effectively improves the cell volume utilization rate and assembly performance, thereby directly improving the energy density of the battery; on the other hand, the rolling process significantly affects the interfacial bonding strength between the active material and the current collector, while optimizing the pore distribution structure among the active material, conductive agent and binder inside the battery electrode. These changes in microstructure ultimately determine the various electrochemical performance indicators of the battery.

[0004] However, in the actual operation of existing rolling mills, although the battery electrode rolls play a crucial role in guiding and transporting the battery electrodes, the stress on the electrodes is concentrated at the boundary between the coated area (i.e., the paint area) and the uncoated area (i.e., the blank area) when the electrodes pass through the rolls. This leads to wrinkles easily appearing in the blank area. This problem not only affects the appearance quality of the battery electrodes, but more importantly, it may damage the integrity of the internal structure of the battery electrodes, thus adversely affecting subsequent battery assembly processes and the performance of the final product.

[0005] Therefore, how to effectively solve the problem of wrinkles in the blank area of ​​battery electrodes during the rolling process has become a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0006] The purpose of this utility model is to provide a battery electrode sheet passing roller and a roller press to solve the problem in the related technology that when the battery electrode sheet passes through the existing passing roller, the force on the battery electrode sheet is concentrated at the junction of the coated area (i.e., the coated area) and the blank area (i.e., the uncoated area), which makes the blank area prone to wrinkling defects.

[0007] On one hand, this utility model provides a battery electrode sheet guide roller, which includes:

[0008] The roller body has a first area opposite to the coating area of ​​the battery electrode and a second area opposite to the blank area of ​​the battery electrode, and the first area and the second area are arranged sequentially along the axial direction of the roller body.

[0009] An annular protrusion is disposed on the roller body and located in the first region, and at least one of the annular protrusions is disposed in the first region.

[0010] On the other hand, this utility model provides a roller press, including the battery electrode passing through the roller in any of the above-mentioned embodiments.

[0011] The beneficial effects of this utility model are as follows:

[0012] This utility model provides a battery electrode sheet guide roller and a roller press. The battery electrode sheet guide roller includes a roller body and an annular protrusion. The roller body is provided with a first area opposite to the coated area of ​​the battery electrode sheet and a second area opposite to the uncoated area of ​​the battery electrode sheet. The first area and the second area are arranged sequentially along the axial direction of the roller body. The annular protrusion is provided on the roller body and located in the first area, and the first area is provided with at least one annular protrusion. When the roller press equipped with this battery electrode sheet guide roller is working, the battery electrode sheet passes through the battery electrode sheet guide roller to guide and transport the battery electrode sheet. During this process, the coated area on the battery electrode sheet abuts against the first area, and the uncoated area on the battery electrode sheet faces the second area. Since the battery electrode sheet guide roller has an annular protrusion in the first area, the annular protrusion lifts the coated area, thereby transferring the stress concentration area from the boundary between the uncoated area and the coated area to the first area. Since the hardness of the coated area corresponding to the first area is greater than that of the uncoated area corresponding to the second area, wrinkles are less likely to occur. This improves the appearance quality of the battery electrode, avoids damaging the integrity of the internal structure of the battery electrode, and avoids adverse effects on subsequent battery assembly processes and the performance of the final product. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the interaction between the battery electrode sheet and the battery electrode sheet in Embodiment 1 of this utility model;

[0014] Figure 2 This is an axial side view of the battery electrode sheets passing through the roller in Embodiment 1 of this utility model;

[0015] Figure 3 This is a schematic diagram of the structure of the battery electrode sheet passing through the roller in Embodiment 1 of this utility model.

[0016] In the picture:

[0017] 100. Battery electrode; 101. Coated area; 102. Blank area;

[0018] 1. Roller body; 11. First zone; 12. Second zone; 2. Annular protrusion; 21. Rounded corner. Detailed Implementation

[0019] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Moreover, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0021] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0022] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0023] Example 1

[0024] A complete battery consists of battery electrodes (positive electrode + negative electrode), electrolyte, separator, and casing. Battery electrodes are the core functional components of the battery, and together with the electrolyte and separator, they form a "cell" unit.

[0025] Battery electrodes are composed of conductive materials, active substances, binders, etc. The main manufacturing process of battery electrodes includes: mixing raw materials such as active substances, binders, and conductive agents in a specific weight ratio to prepare a uniform slurry; then uniformly coating the slurry onto the surface of an aluminum or copper foil current collector according to the preset battery electrode areal density requirements; and finally drying to remove the solvent from the slurry to form the battery electrode. In subsequent processes, the rolled battery electrodes are continuously rolled to a specified thickness using a roll press, and finally, the slitting and tab forming processes are completed.

[0026] The battery electrode consists of alternating coating areas (areas coated with slurry) and blank areas (empty foil areas):

[0027] Coating area: Coated with positive and negative electrode slurries, it is the core area for energy storage. The slurry layer coated on the coating area is called the coating layer.

[0028] Blank area: The area where no paste is applied is the exposed area of ​​copper foil (negative electrode) or aluminum foil (positive electrode), which is used for subsequent processes such as welding tabs, positioning and cutting, and thermal bonding.

[0029] In existing rolling mills, the battery electrodes need to be transferred and guided by rollers during the rolling process. However, because the rollers only support the coating area 101, and there is a height difference between the blank area 102 and the coating area 101, the blank area 102 cannot fully contact the rollers. Therefore, the stress on the battery electrode is concentrated at the interface between the blank area 102 and the coating area 101. Furthermore, since the hardness of the blank area 102 is lower than that of the coating area 101, wrinkles are easily formed in the blank area 102. This problem not only affects the appearance quality of the battery electrodes but, more importantly, may damage the integrity of the internal structure, thus adversely affecting subsequent battery assembly processes and the performance of the final product.

[0030] To solve the above problems, such as Figures 1-3As shown, this embodiment provides a battery electrode roller, which includes a roller body 1 and an annular protrusion 2. The roller body 1 is provided with a first region 11 opposite to the coating area of ​​the battery electrode 100 and a second region 12 opposite to the blank area 102 of the battery electrode 100. The first region 11 and the second region 12 are arranged sequentially along the axial direction of the roller body 1. The annular protrusion 2 is provided on the roller body 1 and located in the first region 11. The first region 11 is provided with at least one annular protrusion 2. When the roller press equipped with the battery electrode guide roller is working, the battery electrode 100 passes through the battery electrode guide roller to guide and transport the battery electrode 100. During this process, the coated area 101 on the battery electrode 100 is in contact with the first area 11, and the blank area 102 on the battery electrode 100 is in contact with the second area 12. Since the battery electrode guide roller has an annular protrusion 2 in the first area 11, the annular protrusion 2 lifts the coated area 101, causing the boundary between the blank area 102 and the coated area 101 to be spaced apart from the roller body 1. This transfers the stress concentration area from the boundary between the blank area 102 and the coated area 101 to the first area 11. Since the hardness of the coated area 101 corresponding to the first area 11 is greater than that of the blank area 102 corresponding to the second area 12, wrinkles are less likely to occur. This improves the appearance quality of the battery electrode 100, avoids damaging the integrity of the internal structure of the battery electrode 100, and avoids adverse effects on subsequent battery assembly processes and the performance of the final product.

[0031] Optionally, the width of the annular protrusion 2 is 'a', where 'a' is in mm and 3 ≤ a ≤ 20. In this embodiment, when the coating area 101 of the battery electrode 100 abuts against the annular protrusion 2, if the width 'a' of the annular protrusion 2 is too small, it is easy to cause the force to concentrate at the point where the coating area 101 of the battery electrode 100 abuts against the annular protrusion 2, which can easily damage the coating of the coating area 101. If the width 'a' of the annular protrusion 2 is too large, although it can effectively disperse the force at the point where the coating area 101 abuts against the annular protrusion 2, it will significantly reduce the contact area between the battery electrode 100 and the roller body 1, resulting in insufficient friction between the roller body 1 and the battery electrode 100, which in turn causes slippage. This not only affects the quality of the coating but also affects the transmission and guiding efficiency of the battery electrode on the roller. In addition, if the width 'a' of the annular protrusion 2 is too large, it will increase the manufacturing cost of the battery electrode roll. Through experiments, it was found that when the value of 'a' is kept within the range of 3≤a≤20, the coating of the coating area 101 will not be damaged, and the transmission and guiding efficiency of the battery electrode roll will not be affected. At the same time, the manufacturing cost of the battery electrode roll can be effectively reduced.

[0032] Optionally, the value of 'a' can be one of 3, 8, 12, 15, 18, and 20.

[0033] Optionally, the protrusion height of the annular protrusion 2 relative to the roller body 1 is h, where h is in μm and 80≤h≤160. In this embodiment, the larger the protrusion height h of the annular protrusion 2, the greater the interaction force between the annular protrusion 2 and the contact position of the coating area 101 of the battery electrode 100, and the easier it is to damage the material layer of the coating area 101. If the protrusion height h of the annular protrusion 2 is too small, the stress concentration area of ​​the battery electrode 100 is not easy to move from the boundary position between the blank area 102 and the coating area 101 to the coating area 101, which may lead to wrinkles in the current collector of the blank area 102. In summary, through experiments, it was found that when the protrusion height h of the annular protrusion 2 is 80≤h≤160, it can ensure that the stress concentration area of ​​the battery electrode 100 moves from the boundary position between the blank area 102 and the coating area 101 to the coating area 101, while also avoiding damage to the coating of the coating area 101.

[0034] Optionally, the value of h can be one of 80, 90, 100, 130, 150 and 160.

[0035] Optionally, a second zone 12 is provided on both sides of the first zone 11, and two annular protrusions 2 are provided at intervals along the axial direction of the roller body 1 in the first zone 11. In this embodiment, compared with providing only one annular protrusion 2, this arrangement can better transfer the stress concentration area from the boundary between the blank area 102 and the coating area 101 to the first zone 11. Optionally, the distance between two adjacent annular protrusions 2 along the axial direction of the roller body 1 is greater than or equal to 20 mm.

[0036] Optionally, the width of the second region 12 between two adjacent first regions 11 is b, where b is in mm, and 40 ≤ b ≤ 100; the distance between the edge of the second region 12 and the edge adjacent to the annular protrusion 2 is L, where L is in mm, and 8 ≤ L ≤ 80. In this embodiment, the width of the second region 12 and the distance between the annular protrusion 2 and the second region 12 both affect whether the stress concentration area of ​​the battery electrode 100 can move from the boundary between the blank area 102 and the coating area 101 to the coating area 101. Therefore, by obtaining 40 ≤ b ≤ 100 and 8 ≤ L ≤ 80 through experiments, it can be ensured that the stress concentration area of ​​the battery electrode 100 can move from the boundary between the blank area 102 and the coating area 101 to the coating area 101.

[0037] For example, the value of b can be one of 40, 60, 80 and 100, and the value of L can be one of 8, 20, 40, 60 and 80.

[0038] Optionally, the distances between the second region 12 and the annular protrusions 2 on both sides are L1 and L2, respectively, and L1 and L2 are not equal. In this embodiment, provided that the stress concentration area can be moved from the boundary between the blank area 102 and the coating area 101 to the coating area 101, the distances between the annular protrusions 2 on both sides of the blank area 102 and the blank area 102 do not need to be the same.

[0039] In other embodiments, the annular protrusions 2 on both sides of the second region 12 are equidistant from the second region 12, i.e., L1 = L2.

[0040] Optionally, the units of L1 and L2 are both mm, and 20≤L1+L2≤100. In this embodiment, this setting can ensure that the stress concentration area of ​​the battery electrode 100 can be moved from the boundary position between the blank area 102 and the coating area 101 to the coating area 101.

[0041] Optionally, the annular protrusion 2 is detachably connected to the roller body 1. In this embodiment, since the force between the annular protrusion 2 and the battery electrode 100 is greater than the force between the roller body 1 and the battery electrode 100, the annular protrusion 2 experiences greater wear relative to the roller body 1 with long-term use of the battery electrode roller. Therefore, the annular protrusion 2 is detachably connected to the roller body 1, and when the annular protrusion 2 is worn significantly, it can be directly replaced, thereby reducing the usage cost of the battery electrode roller.

[0042] Optionally, the annular protrusion 2 is a tape wrapping component. In this embodiment, after determining the position and size of the annular protrusion 2 on the roller body 1, tape with the same width a as the annular protrusion 2 is wrapped to the designated position of the roller body 1. Then, based on the protrusion height h of the annular protrusion 2 relative to the roller body 1, the number of wrapping turns of the tape is determined, and finally, the required annular protrusion 2 is obtained.

[0043] Specifically, the height of the annular protrusion 2 relative to the roller body 1 is h, the thickness of the tape is c, and the number of wrapping turns of the tape winding component is q = h / c. Optionally, the number of wrapping turns q of the tape winding component can be 1 turn, 2 turns, or 3 turns, etc.

[0044] Optionally, the tape can be made of Teflon. In this embodiment, Teflon has extremely low surface tension and adheres almost entirely to no substance. The thin-film coating also maintains good non-stick properties, thus preventing coating adhesion. Teflon can withstand temperatures up to 300°C for short periods, and its typical continuous operating temperature range is -180°C to 260°C. During use, the annular protrusion 2 is less prone to deformation, ensuring that the stress concentration area can move from the boundary between the blank area 102 and the coated area 101 to the coated area 101, while simultaneously improving the durability of the annular protrusion 2. Teflon has an extremely low coefficient of friction, reducing wear and power consumption between it and the battery electrode 100. Teflon is resistant to corrosion from strong acids, strong alkalis, and organic solvents, preventing corrosion of the coating on the battery electrode 100.

[0045] In other embodiments, an annular limiting groove is recessed on the roller body 1 at the position corresponding to the annular protrusion 2. The annular protrusion 2 includes a first retaining ring and a second retaining ring, which are respectively disposed in the annular limiting groove, so as to provide an annular protrusion 2 on the roller body 1.

[0046] Regarding how the first and second retaining rings are fixed on the roller body 1, optionally, the first and second retaining rings are connected to each other to hold tightly on the roller body 1. For example, one end of the first retaining ring and one end of the second retaining ring are pivotally connected, the other end of the first retaining ring is provided with a clip, and the other end of the second retaining ring is provided with a buckle. The clip and the buckle are engaged, thereby holding the first and second retaining rings tightly on the roller body 1.

[0047] In other embodiments, the first retaining ring and the second retaining ring are detachably connected to the roller body 1 by adhesive bonding or screwing. For example, the annular limiting groove is coated with adhesive, and the first and second retaining rings are disposed within the annular limiting groove, thereby attaching the first and second retaining rings to the roller body 1. Alternatively, the bottom wall of the annular limiting groove has multiple threaded holes, and the first and second retaining rings are respectively provided with countersunk holes. Bolts pass through the countersunk holes and are screwed into the corresponding threaded holes to fix the first and second retaining rings to the roller body 1.

[0048] Optionally, multiple annular protrusions 2 are provided, and the thickness of the first retaining ring and the second retaining ring in the multiple annular protrusions 2 is different. This arrangement makes the protrusion height h of the annular protrusions 2 relative to the roller body 1 different when different annular protrusions 2 are installed on the roller body 1, so that the annular protrusions 2 with a more suitable height can be replaced according to the actual working effect.

[0049] Optionally, the annular protrusion 2 is provided with a microtexture on its outer peripheral surface opposite to the coating area 101. In this embodiment, the annular protrusion 2 is used to prepare an array of pits with a diameter of 15μm-50μm on its outer peripheral surface opposite to the coating area 101 using femtosecond laser pulses. This reduces the coefficient of friction on the outer peripheral surface of the annular protrusion 2, reduces wear on the coating area 101, and extends the service life of the battery electrode roll.

[0050] Optionally, the pits that make up the microtexture are arranged in a rectangular array.

[0051] Compared to the rectangular cross-section of the annular protrusion 2 along the radial direction, when the coating area 101 abuts against the outer peripheral surface of the annular protrusion 2, the bending angle of the coating area 101 at both sides of the annular protrusion 2 is relatively large, which can easily cause damage to the coating of the coating area 101. To improve this problem, optionally, the annular protrusion 2 is provided with rounded corners at both ends along the axial direction of the roller body 1. In this embodiment, the coating area 101 achieves a rounded transition on the outer peripheral surface of the annular protrusion 2 through rounded corners, which effectively reduces the bending angle of the coating area 101 at both sides of the annular protrusion 2, thereby improving the damage to the coating of the coating area 101 caused by the annular protrusion 2.

[0052] In other embodiments, the annular protrusion 2 has an arched cross-section along the radial direction. This arrangement causes the coating area 101 to transition to an arc on the outer peripheral surface of the annular protrusion 2, effectively reducing the bending angle of the coating area 101 at both sides of the annular protrusion 2, thereby improving the damage to the coating of the coating area 101 caused by the annular protrusion 2.

[0053] This embodiment also provides a roller press, including the battery electrode passing through the roller in the above scheme.

[0054] Optionally, the roller press also includes a frame, a drive unit, a pressure roller, a drive roller, and a driven roller. The drive roller, pressure roller, driven roller, and battery electrode passing roller are all rotatably mounted on the frame. The drive unit drives the rotating roller to rotate so that the battery electrode 100 moves between the drive roller and the driven roller. The pressure roller is used to press the battery electrode 100 thinner, and the battery electrode passing roller is used to support and guide the battery electrode 100.

[0055] Example 2

[0056] This embodiment is basically the same as Embodiment 1, except that the annular protrusion 2 and the roller body 1 are integrally formed. In this embodiment, the annular protrusion 2 and the roller body 1 can be machined by turning. In other embodiments, they can also be machined by additive manufacturing. This configuration makes the manufacturing precision of the battery electrode roller higher.

[0057] Example 3

[0058] This embodiment is basically the same as Embodiment 1, except that the annular protrusion 2 has two states relative to the roller body 1 along the axial direction: one is relatively sliding, and the other is relatively fixed. In this embodiment, this setting can adjust the relative position of the annular protrusion on the roller body 1 to accommodate different types of battery electrode sheets 100.

[0059] To adjust the relative position of the annular protrusion 2 on the roller body 1, optionally, the relative position of the annular protrusion 2 on the roller body 1 is adjusted according to the width dimensions of the coating area 101 and the blank area 102 on the battery electrode 100 along the axial direction of the roller body 1. After the adjustment is completed, the annular protrusion 2 is fixed relative to the roller body 1 to achieve coarse adjustment of the annular protrusion 2 and the roller body 1.

[0060] Then, the battery electrode sheet passing through the roller is tested to see if wrinkles will form in the blank area 102 when the battery electrode sheet 100 passes through the roller. If wrinkles are formed, the annular protrusion 2 is finely adjusted and fixed relative to the roller body 1. The test is repeated to see if wrinkles will form in the blank area 102 when the battery electrode sheet 100 passes through the roller. The above steps are repeated until wrinkles are no longer formed in the blank area 102 of the battery electrode sheet 100, so as to achieve fine adjustment of the annular protrusion 2 and the roller body 1.

[0061] Regarding how the annular protrusion 2 can achieve both relatively fixed and relatively sliding states on the roller body 1, for example, the annular protrusion 2 is sleeved on the roller body 1, and the annular protrusion 2 and the roller body 1 are glued and fixed by applying an adhesive between the annular protrusion 2 and the roller body 1. When it is necessary for the annular protrusion 2 and the roller body 1 to slide relative to each other to adjust their relative positions, an adhesive release agent is added between the annular protrusion 2 and the roller body 1 to achieve relative sliding between the annular protrusion 2 and the roller body 1.

[0062] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery electrode sheet passing through a roller, characterized in that, include: The roller body (1) is provided with a first region (11) opposite to the coating area (101) of the battery electrode (100) and a second region (12) opposite to the blank area (102) of the battery electrode (100). The first region (11) and the second region (12) are arranged sequentially along the axial direction of the roller body (1). An annular protrusion (2) is disposed on the roller body (1) and located in the first region (11), and at least one annular protrusion (2) is disposed in the first region (11).

2. The battery electrode rolling mill according to claim 1, characterized in that, The width of the annular protrusion (2) is a, where a is in mm, and 3 ≤ a ≤ 20.

3. The battery electrode rolling mill according to claim 1, characterized in that, The height of the annular protrusion (2) relative to the roller body (1) is h, where h is in μm and 80≤h≤160.

4. The battery electrode rolling process according to claim 1, characterized in that, The first region (11) is provided with the second region (12) on both sides, and the first region (11) is provided with two annular protrusions (2) at intervals along the axial direction of the roller body (1).

5. The battery electrode rolling mill according to claim 1 or 4, characterized in that, The width of the second region (12) between two adjacent first regions (11) is b, where b is in mm and 40 ≤ b ≤ 100; The distance between the edge of the second region (12) and the edge adjacent to the annular protrusion (2) is L, where L is in mm and 8 ≤ L ≤ 80.

6. The battery electrode rolling mill according to claim 5, characterized in that, The distances between the second region (12) and the annular protrusions (2) on both sides are L1 and L2, respectively, and L1 and L2 are not equal.

7. The battery electrode rolling mill according to claim 5, characterized in that, The distances between the second region (12) and the annular protrusions (2) on both sides are L1 and L2, respectively, and L1 and L2 are equal.

8. The battery electrode rolling process according to claim 6 or 7, characterized in that, The units for L1 and L2 are both mm, and 20 ≤ L1 + L2 ≤ 100.

9. The battery electrode rolling mill according to any one of claims 1-7, characterized in that, The distance between two adjacent annular protrusions (2) along the axial direction of the roller body (1) is greater than or equal to 20 mm.

10. The battery electrode rolling mill according to any one of claims 1-7, characterized in that, The annular protrusion (2) is detachably connected to the roller body (1).

11. The battery electrode rolling mill according to claim 10, characterized in that, The annular protrusion (2) is a Teflon tape wrapping component.

12. The battery electrode rolling mill according to any one of claims 1-7, characterized in that, The annular protrusion (2) and the roller body (1) are integrally formed.

13. The battery electrode rolling mill according to any one of claims 1-7, characterized in that, The annular protrusion (2) is used to provide a microtexture on the outer peripheral surface opposite to the coating area (101).

14. The battery electrode rolling process according to any one of claims 1-7, characterized in that, The annular protrusion (2) has rounded corners at both ends along the axial direction of the roller body (1).

15. The battery electrode rolling mill according to any one of claims 1-7, characterized in that, The annular protrusion (2) has two states relative to the roller body (1) along the axial direction of the roller body (1): relatively sliding and relatively fixed.

16. A roller press, characterized in that, Including the battery electrode rolling process according to any one of claims 1-15.

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