A rolling device and pole piece processing apparatus

Abstract

The application discloses a rolling device and a pole piece processing equipment, and relates to the technical field of battery processing. The rolling device can roll a pole piece. The pole piece is provided with a hollow foil area and a coating area. The rolling device comprises a roller shaft body and a rolling piece. The roller shaft body comprises first roller shaft sections and second roller shaft sections which are alternately arranged along a first direction. The first roller shaft sections are used for rolling the coating area of the pole piece. The rolling piece is arranged around the circumference of the second roller shaft sections. The rolling piece is used for rolling the hollow foil area of the pole piece. The outer circumferential surface of the rolling piece is provided with a plurality of protruding structures which are arranged at intervals along the circumferential direction of the second roller shaft sections. Therefore, the hollow foil area can form a reinforcing rib similar to a "concave-convex fluctuation" after rolling, so that the bending resistance of the hollow foil area is improved. In subsequent processing, the pole lug processed from the hollow foil area is not easy to be bent, and thus the yield of products is improved.

Description

Technical Field

[0001] This application belongs to the field of battery processing technology, specifically relating to a rolling device and electrode processing equipment. Background Technology

[0002] During the manufacturing process, battery electrodes need to be rolled by a rolling device. This is done to ensure that the thickness of the electrodes is rolled evenly to meet the process parameter requirements, and to enhance the adhesion strength between the active material and the foil.

[0003] During this process, because the empty foil area on the electrode cannot be stretched well, the tabs formed by die-cutting the empty foil area in subsequent processing are prone to folding, resulting in a low product yield. Utility Model Content

[0004] This application aims to provide a rolling device and electrode processing equipment that can solve the problem that the tabs formed by die-cutting the empty foil area on the electrode are prone to folding during subsequent processing due to the inability to stretch the empty foil area well, resulting in a low product yield.

[0005] To solve the above-mentioned technical problems, this application is implemented as follows:

[0006] In a first aspect, embodiments of this application propose a rolling device capable of rolling an electrode sheet, the electrode sheet having an empty foil area and a coating area, comprising: a roller shaft body and a rolling element, the roller shaft body comprising a first roller shaft segment and a second roller shaft segment alternately arranged along a first direction, the first roller shaft segment being used to roll the coating area of ​​the electrode sheet; the rolling element being circumferentially arranged around the second roller shaft segment; the rolling element being used to roll the empty foil area of ​​the electrode sheet; the outer peripheral surface of the rolling element having a plurality of protrusion structures, the plurality of protrusion structures being spaced apart along the circumferential direction of the second roller shaft segment.

[0007] Optionally, along the first direction, the rolling element has a stepped structure on at least one side edge, and the stepped structure rolls the boundary position between the empty foil area and the coated area in the electrode sheet.

[0008] Optionally, the roll forming member includes a first roll forming layer and a second roll forming layer. The first roll forming layer is connected to the outer peripheral surface of the second roller shaft segment. The second roll forming layer includes a plurality of adhesive members. Along the circumferential direction of the second roller shaft segment, the plurality of adhesive members are spaced apart and arranged around the side of the first roll forming layer opposite to the roller shaft body. The adhesive members form the protrusion structure. Along the first direction, the length of the first roll forming layer is greater than the length of the second roll forming layer. The stepped structure includes a first stepped structure formed between the first roll forming layer and the second roll forming layer.

[0009] Optionally, the roll forming member further includes a third roll forming layer, which surrounds and covers the side of the second roll forming layer opposite to the first roll forming layer; along the first direction, the length of the second roll forming layer is greater than the length of the third roll forming layer, and the stepped structure further includes a second stepped structure formed between the second roll forming layer and the third roll forming layer.

[0010] Optionally, along the circumferential direction of the roller body, the spacing between two adjacent adhesive parts is W1 mm, satisfying: 2≤W1≤10;

[0011] And / or, the width of the adhesive is W2 mm, satisfying: 2≤W2≤10.

[0012] Optionally, the electrode further includes a dispensing area S2 disposed between the empty foil area and the coating area, the length of the dispensing area along the first direction being L1 mm;

[0013] Along the first direction, the length difference between the first roll-pressed layer and the second roll-pressed layer on any side of the first stepped structure is L2mm, which satisfies: L1 / 4+1≤L2≤L1 / 4+5;

[0014] Along the first direction, the length difference between the second roll-pressed layer and the third roll-pressed layer on any side of the second stepped structure is L3mm, which satisfies: 3L1 / 4-5≤L3≤3L1 / 4-1.

[0015] Optionally, the roller pressing device shall satisfy at least one of the following conditions:

[0016] A. Along the radial direction of the roller body, the thickness of the first roll-pressed layer is d1μm, 80≤d1≤160;

[0017] B. Along the radial direction of the roller body, the thickness of the second roll-pressed layer is d2μm, 160≤d2≤320;

[0018] C. Along the radial direction of the roller body, the thickness of the third roll layer is d3μm, 80≤d4≤160.

[0019] Optionally, along the radial direction of the roller body, the orthographic projection of the protrusion structure on the outer peripheral surface of the second roller section is one or more of the following: S-shape, triangle, quadrilateral, trapezoid.

[0020] Optionally, multiple rollers are provided, and the multiple rollers are spaced apart along the first direction.

[0021] Secondly, embodiments of this application provide an electrode processing apparatus, including: a roller pressing device as described in any of the above claims.

[0022] In the embodiments of this application, the rolling device is capable of rolling an electrode sheet, which has an empty foil area and a coating area. The rolling device includes a roller shaft body and a rolling element. The roller shaft body includes a first roller shaft segment and a second roller shaft segment arranged alternately along a first direction. The first roller shaft segment is used to roll the coating area of ​​the electrode sheet. The rolling element is arranged circumferentially around the second roller shaft segment and is used to roll the empty foil area of ​​the electrode sheet. The outer circumferential surface of the rolling element has multiple protrusions, which are spaced apart along the circumferential direction of the second roller shaft segment. This allows the empty foil area to form a reinforcing rib similar to "undulations" after rolling, thereby improving the bending resistance of the empty foil area. In subsequent processing, the electrode tabs formed by processing the empty foil area are less prone to bending, thus improving the product yield.

[0023] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0024] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0025] Figure 1 This is a schematic diagram of the roller pressing device according to an embodiment of this application from one perspective;

[0026] Figure 2 This is a schematic diagram of the roller pressing device from another perspective according to an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of the roller pressing device for pressing electrode sheets according to an embodiment of this application;

[0028] Figure 4 According to the embodiments of this application Figure 3 Enlarged view of section B;

[0029] Figure 5 According to the embodiments of this application Figure 1 The first schematic diagram of section A;

[0030] Figure 6 According to the embodiments of this application Figure 1 The second schematic diagram of section A;

[0031] Figure 7 According to the embodiments of this application Figure 1 The third schematic diagram of section A;

[0032] Figure 8 According to the embodiments of this application Figure 1 The fourth type of diagram for section A.

[0033] Figure label:

[0034] 1: Electrode; S1: Empty foil area; S2: Dispensing area; S3: Coating area; 2: Roller body; 20: First roller section; 21: Second roller section; 3: Rolling component; 31: Protrusion structure; 32: Stepped structure; 32a: First stepped structure; 32b: Second stepped structure; 33: First rolled layer; 34: Second rolled layer; 341: Adhesive component; 342: First adhesive layer; 343: Second adhesive layer; 35: Third rolled layer; W1: Spacing between two adjacent second rolled layers; W2: Width of the second rolled layer; L1: Length of the dispensing area along the first direction of the roller body; L2: Length difference between the first and second rolled layers; L3: Length difference between the second and third rolled layers; d1: Thickness of the first rolled layer; d2: Thickness of the second rolled layer; d3: Thickness of the third rolled layer; X: First direction. Detailed Implementation

[0035] The embodiments of this application will now be described in detail. Examples of these embodiments are illustrated 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 application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0036] The terms "first" and "second" in the specification and claims of this application may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0037] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and 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, and therefore should not be construed as a limitation of this application.

[0038] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" 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 between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] Before explaining the rolling device and electrode processing equipment provided in the embodiments of this application, the application scenarios of the rolling device and electrode processing equipment provided in the embodiments of this application will be specifically described:

[0040] In the electrode processing of related technologies, after the electrode 1 undergoes the coating process, it needs to be rolled by a rolling device to achieve the required process parameters. During this process, due to the different thicknesses of the coating area S3 and the empty foil area S1 on the electrode 1, the foil stretching conditions of the two areas are different.

[0041] After the rolling process is completed, electrode 1 will enter the die-cutting process. The die-cutting process will use laser to cut the foil in the empty foil area into the electrode tabs of the electrode. If the foil is not stretched enough, the tabs will not have enough support after forming and will collapse, which will easily cause them to fold, resulting in a low product yield and safety hazards.

[0042] Therefore, this application provides a rolling device and an electrode processing equipment. The rolling device and electrode processing equipment provided in this application will be described in detail below with reference to the accompanying drawings and through specific embodiments and application scenarios.

[0043] like Figure 1 , Figure 2 , Figure 3 As shown, according to some embodiments of this application, a rolling device is capable of rolling an electrode sheet 1. The electrode sheet 1 is provided with an empty foil area S1 and a coating area S3. The rolling device includes: a roller body 2 and a rolling member 3. The roller body 2 includes a first roller section 20 and a second roller section 21 arranged alternately along a first direction X. The first roller section 20 is used to roll the coating area S3 of the electrode sheet. The rolling member 3 is arranged circumferentially around the second roller section 21. The rolling member 3 is used to roll the empty foil area S1 of the electrode sheet 1. The outer peripheral surface of the rolling member 3 has a plurality of protrusion structures 31, which are spaced apart along the circumferential direction of the second roller section 21.

[0044] In this embodiment, the outer peripheral surface of the roller pressing member 3 has a plurality of protrusions 31, which are arranged at intervals along the circumferential direction of the second roller shaft section 21. After the roller pressing member 3 rolls the empty foil area S1 of the electrode sheet 1, a reinforcing rib similar to "undulation" will be formed in the empty foil area S1 to improve the bending resistance of the empty foil area S1. In subsequent processing, the electrode tabs processed from the empty foil area S1 are less likely to be bent, thereby improving the yield of the product; at the same time, it can reduce the safety hazards in subsequent processing.

[0045] In specific applications, such as Figure 3 and Figure 4 As shown, electrode 1 includes an empty foil area S1, a dispensing area S2, and a coating area S3. The coating area S3 specifically refers to the area where the foil of electrode 1 is coated with active material, and the empty foil area S1 specifically refers to the area where no active material is coated. The dispensing area S2 is located between the empty foil area S1 and the coating area S3. The dispensing area S2 specifically refers to the area between the empty foil area S1 and the coating area S3 where a ceramic layer is coated to insulate and isolate the empty foil area S1 and the coating area S3. The active material is a substance that participates in the flow reaction and can be a positive electrode active material or a negative electrode active material, such as lithium cobalt oxide (LiCoO3), nickel cobalt manganese oxide (NMC), graphite, silicon, etc.

[0046] Specifically, the first direction X is the axial direction of the roller body 2; the roller pressing component 3 is arranged circumferentially around the second roller section 21, and the first roller section 20 and the second roller section 21 are arranged alternately along the first direction X, so that during the rolling process, the roller pressing component 3 is adapted to the empty foil area S1 of the electrode 1, thereby rolling the empty foil area S1; while the first roller pressing section 20 is adapted to the coating area S3 of the electrode 1, so as to roll the coating area S3.

[0047] It should be noted that the first roller section 20 and the second roller section 21 can be integrally formed parts, for example, by setting alternating areas along the axial direction on the same optical axis to form the first roller section and the second roller section; or they can be separate formed parts, for example, by alternately welding the second roller section 21 and the first roller section 20 to form the roller body 2. Those skilled in the art can make the settings according to actual needs.

[0048] It should be explained that the number of rollers 3 is matched with the number of empty foil areas S1 on the electrode 1. That is, the number of empty foil areas S1 on the electrode 1 to be rolled is the number of rollers 3. For example, the number of rollers 3 can be set to any number of 1, 2, 3, 4, 5, 6, etc.

[0049] Understandably, the rolling element 3 and the second roller shaft section 32 can be integrally formed. For example, grooves are cut at intervals along the axial direction of an optical axis, the optical axis section where the grooves are located is the first roller shaft section 20, and the remaining uncut parts form the second roller shaft section 32 and the rolling element 3. During specific rolling, a buffer layer is coated or pasted on the outer surface of the uncut parts to reduce damage to the electrode 1 when rolling the empty foil area S1 of the electrode 1. The rolling element 3 and the second roller shaft section 32 can also be separate formed parts. For example, along the axial direction of the optical axis, polytetrafluoroethylene cards or Teflon tapes are pasted at intervals on the outer surface of the optical axis to form the rolling element 3. The pasted optical axis section is the second rolling section 21, and the unpainted optical axis section is the first rolling section 20. Of course, other structural forms that can form the rolling element 3 are also possible. Those skilled in the art can make settings according to actual needs, and this application does not limit them.

[0050] It should be noted that the protruding structure 31 is disposed on the outer peripheral surface of the roller pressing part 3. In actual processing, for example, multiple pieces of polytetrafluoroethylene card or Teflon tape can be pasted at intervals along the circumferential direction of the roller body 2 to form the protruding structure 31; of course, it can also be formed by cutting the optical axis or other methods. Those skilled in the art can set it according to actual needs, and this application does not limit it.

[0051] In practical applications, the bending rate of foil is K = M / EI, where K is the bending rate, M is the load, E is the elastic modulus, and I is the moment of inertia. According to the formula, the bending rate K is directly proportional to the load M and inversely proportional to the product of the elastic modulus E and the moment of inertia I. Under the same load and material conditions, a larger moment of inertia makes bending more difficult. The moment of inertia I is only related to the size and shape of the cross-section (I = ∑y²*S, where y is the longitudinal intercept and S is the area). That is, the larger the cross-sectional area under stress, the larger the moment of inertia I, and the stronger the foil's resistance to bending. Normal foil is a flat, straight 'I' shape, resulting in a small area of ​​stress per unit length. When regular raised morphology is formed on the foil surface, the area of ​​stress per unit length increases, the moment of inertia I increases, and the bending resistance improves.

[0052] Therefore, when multiple protruding structures 31 are arranged at intervals along the circumferential direction of the second roller shaft section 21, after the multiple protruding structures 31 roll the empty foil area S1 of the electrode sheet 1, they form "undulating" reinforcing ribs on the empty foil area S1 of the electrode sheet 1. This ensures that the reinforcing ribs also exist on the electrode tabs formed by die-cutting the empty foil area S1 in subsequent processing. In this way, the unit force-bearing area increases under the same length of electrode tab, the moment of inertia I increases, the bending resistance is improved, and the yield of the product is improved. At the same time, it can reduce safety hazards in subsequent processing.

[0053] like Figure 1 and Figure 3As shown, in some embodiments of this application, along the first direction X, the roller pressing member 3 has a stepped structure 32 on at least one side edge, and the stepped structure 32 is located at the junction of the hollow foil area S1 and the coating area S3 in the roller pressing electrode sheet 1.

[0054] In this embodiment, a stepped structure 32 is provided on at least one edge of the rolling member 3, so that the junction of the hollow foil area S1 and the coating area S3 of the electrode 1 can be rolled through the stepped structure 32, so that the extensibility of the foil in the hollow foil area S1, the dispensing area S2 and the coating area S3 of the electrode 1 is consistent, and the effect of the tension of the ceramic layer and the active material layer on the dispensing area S2 and the coating area S3 on the stretching of the foil is reduced, so that the foil in the hollow foil area S1 can be rolled better and thus fully stretched.

[0055] It needs to be explained that when the ceramic layer and active material layer on the dispensing area S2 and coating area S3 are rolled on the electrode 1, due to the inherent properties of the ceramic layer and active material layer, they will generate tension on the foil, which will prevent the foil from being fully stretched when rolled. However, the stepped structure 32 can roll the ceramic layer and active material layer, so that the foil covered by the ceramic layer and active material layer can also be fully stretched, so that the extensibility of the foil in each area is consistent.

[0056] Understandably, such as Figure 3 and Figure 4 As shown, the boundary between the empty foil area S1 and the coating area S3 specifically refers to the dispensing area S2 located between the empty foil area S1 and the coating area S3, as well as at least a portion of the empty foil area S1 and the coating area S3 near the dispensing area S2.

[0057] In specific applications, such as Figure 1 and Figure 3 As shown, the roller pressing component 3 can have stepped structures 32 on both sides or on one side. The stepped structure 32 is adapted to the junction of the empty foil area S1 and the coating area S3 on the electrode sheet 1. For example, when rolling the empty foil area S1 at the edge of the electrode sheet 1, since the empty foil area S1 has a dispensing area S2 and a coating area S3 on only one side, the roller pressing component 3 adapted to this location has a stepped structure 32 on only one side. However, for the empty foil area S1 located in the middle, since the dispensing area S2 and the coating area S3 are provided on both sides, the roller pressing component 3 adapted to this location has a stepped structure 32 on both sides. Those skilled in the art can make adaptive adjustments according to actual needs.

[0058] like Figure 4 , Figure 5 , Figure 6 , Figure 7 and Figure 8As shown, in some embodiments of this application, the roll forming member 3 includes a first roll forming layer 33 and a second roll forming layer 34. The first roll forming layer 33 is connected to the outer peripheral surface of the second roller shaft section 21. The second roll forming layer 34 includes a plurality of adhesive members 341. Along the circumferential direction of the roller shaft body 2, the plurality of adhesive members 341 are spaced around the first roll forming layer 33 on the side away from the second roller shaft section 21. The adhesive members 341 form a protrusion structure 32. Along the first direction X, the length of the first roll forming layer 33 is greater than the length of the second roll forming layer 34. The stepped structure 32 includes a first stepped structure 32a formed between the first roll forming layer 33 and the second roll forming layer 34.

[0059] In this embodiment, along the circumferential direction of the roller body 2, multiple adhesive members 341 are arranged around the first roller pressing layer 33 on the side away from the second roller section 21, thereby forming a raised structure 32 by the adhesive members 341. This allows for the formation of "undulating" reinforcing ribs when rolling the empty foil area S1 of the electrode sheet 1. In specific operations, the raised structure 32 formed by the adhesive members 341 makes it easier to adjust the size of the adhesive members 341 according to the actual size of the rolled electrode sheet 1, thereby adjusting the size of the raised structure 32. This makes the processing more convenient and faster, and the cost is lower. In addition, the length of the first roller pressing layer 33 is greater than the length of the second roller pressing layer 34, thereby forming a first stepped structure 32a between the first roller pressing layer 33 and the second roller pressing layer 34. In this way, the first roller pressing layer 33 and the second roller pressing layer 34 can roll different areas of the electrode sheet 1, thereby further ensuring the consistency of the extension of different areas on the electrode sheet 1 when it is rolled.

[0060] It should be explained that, along the first direction X, the length of the first roll-formed layer 33 is greater than the length of the second roll-formed layer 34. In specific applications, such as... Figure 4 As shown, the first roll-pressing layer 33 can extend into the coating area S3 of the electrode 1, while the second roll-pressing layer 34 can extend into the dispensing area S2 of the electrode 1, thereby rolling different areas on the electrode 1. Since the thicknesses of the empty foil area S1, the dispensing area S2 and the coating area S3 are different, the first stepped structure 32a formed can roll the dispensing area S2 and the coating area S3, thereby improving the extensibility consistency of different areas on the electrode 1.

[0061] It should be noted that, as Figure 3 As shown, in the edge region of the roller body 2, since the empty foil region S1 is provided with a glue-applied area S2 and a coating area S3 on only one side, one end of the first roller layer 33 extends beyond the second roller layer 34 along the first direction X; in the central region of the roller body 2, since the empty foil region S1 is provided with a glue-applied area S2 and a coating area S3 on opposite sides, both ends of the first roller layer 33 extend beyond the second roller layer 34 along the first direction X.

[0062] It should be explained that the first roll forming layer 33 is specifically formed by wrapping Teflon tape around and pasting it on the outer circumferential surface of the roller body 2, and the adhesive component 341 is specifically a card made of polytetrafluoroethylene material or Teflon tape. The second roll forming layer 34 is specifically formed by pasting the adhesive component 341 at intervals along the axial direction of the roller body 2 on the side of the first roll forming layer 33 away from the roller body 2. In this way, the required structure can be formed with low-cost components. At the same time, the roll forming component 3 formed by pasting can be adapted to the electrode sheet 1 of different sizes, thereby improving the applicability of the roll forming device.

[0063] like Figure 2 and Figure 4 As shown, in one embodiment of this application, the second roll-pressed layer 34 includes a first adhesive layer 342 and a second adhesive layer 343. The first adhesive layer 342 is disposed between the first roll-pressed layer 33 and the second adhesive layer 343. Both the first adhesive layer 342 and the second adhesive layer 343 are formed by multiple adhesive members 341 that are circumferentially bonded around the roller body 2. The lengths of the first adhesive layer 342 and the second adhesive layer 343 are the same along the first direction X.

[0064] In this embodiment, the second roller pressing layer 34 is formed by the first adhesive layer 342 and the second adhesive layer 343, so that the adhesive settings can be configured according to actual needs. The first adhesive layer 342 and the second adhesive layer 343 are both formed by circumferentially spaced adhesive members 341 around the roller body 2, which makes it easier to replace during operation.

[0065] Specifically, the first adhesive layer 342 and the second adhesive layer 343 are both formed by bonding the first adhesive layer 342 to the first adhesive layer 343 with the adhesive part 341 of the card or Teflon tape. In this way, the first adhesive layer 342 and the second adhesive layer 343 have the same thickness in the radial direction of the roller body 2 and the same length in the first direction X, which makes the structure of the second roll-pressed layer 34 more regular and is conducive to the regular "reinforcing ribs" at the roll-pressing point when rolling the electrode 1.

[0066] like Figure 1 , Figure 2 , Figure 3 and Figure 4 As shown, in some embodiments of this application, the roll forming member 3 further includes a third roll forming layer 35, which surrounds and covers the side of the second roll forming layer 34 away from the first roll forming layer 33; along the first direction X, the length of the second roll forming layer 34 is greater than the length of the third roll forming layer 35, and the stepped structure 32 further includes a second stepped structure 32b formed between the second roll forming layer 34 and the third roll forming layer 35.

[0067] In this embodiment, a second stepped structure 32b is formed between the second roll-pressed layer 34 and the third roll-pressed layer 35, so that the second roll-pressed layer 34 and the third roll-pressed layer 35 can roll different areas of the electrode 1, thereby further ensuring the consistency of the extension of different areas of the electrode 1 when it is rolled.

[0068] It should be noted that, as Figure 3 As shown, in the edge region of the roller body 2, since the empty foil area S1 is provided with a glue area S2 on only one side, one end of the second roll layer 34 extends beyond the third roll layer 35 along the first direction X; in the central region of the roller body 2, since the empty foil area S1 is provided with glue areas S2 on both sides, both ends of the second roll layer 34 extend beyond the third roll layer 35 along the first direction X.

[0069] It should be explained that the third roll-pressed layer 35 is specifically a Teflon tape. The Teflon tape wraps around and covers the second roll-pressed layer 34 to form the third roll-pressed layer 35, thereby protecting the second roll-pressed layer 34. At the same time, since the second roll-pressed layer 34 and the third roll-pressed layer 35 have different lengths along the first direction X, the second roll-pressed layer 34 can extend into the dispensing area S2 of the electrode 1, and the third roll-pressed layer 35 can extend into the empty foil area S1 and the dispensing area S2, thereby rolling different areas on the electrode 1. Since the thicknesses of the empty foil area S1, the dispensing area S2 and the coating area S3 are different, the second stepped structure 32b formed can roll the empty foil area S1 and the dispensing area S2, thereby improving the uniformity of extension of different areas on the electrode 1.

[0070] like Figure 2 As shown, in some embodiments of this application, the distance between two adjacent adhesive pieces 341 along the circumferential direction of the roller body 2 is W1 mm, satisfying: 2≤W1≤10.

[0071] In this embodiment of the application, by setting the spacing W1 between two adjacent adhesive members 341 in the circumferential direction of the roller body 2 within a reasonable range, the regular protrusion morphology formed on the empty foil area S1 by the roller pressing member 3 after rolling the empty foil area S1 of the electrode sheet 1 is more obvious, that is, the force-bearing area of ​​the foil is larger, thereby strengthening the bending resistance.

[0072] It needs to be explained that when W1 < 2mm, the two adjacent adhesive pieces 341 are too close, which makes it easy for the reinforcing ribs with "undulations" to be formed on the empty foil area S1 after the electrode 1 is rolled. When W1 > 10mm, the two adjacent adhesive pieces 341 are too far apart, which makes the increase in the force-bearing area of ​​the empty foil area S1 after the electrode 1 is rolled by the roller 3 limited, and the bending resistance is not improved enough. As a result, the electrode tabs in the subsequent die-cutting process are still easy to bend.

[0073] In specific applications, the spacing W1 between two adjacent adhesive pieces 341 along the circumferential direction of the roller body 2 can be set to any value or a range between any two values, such as 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm.

[0074] like Figure 2 As shown, in some embodiments of this application, the width of the adhesive 341 along the circumferential direction of the roller body 2 is W2 mm, satisfying: 2≤W2≤10.

[0075] In this embodiment of the application, by setting the width W2 of the adhesive 341 along the circumferential direction of the roller body 2 within a reasonable range, the regular protrusion morphology formed on the empty foil area S1 by the roller pressing member 3 after rolling the empty foil area S1 of the electrode sheet 1 is more obvious, that is, the force-bearing area of ​​the foil is larger, thereby making the bending resistance stronger.

[0076] It needs to be explained that when W2 < 2mm, the width of the adhesive 341 is too small, which makes it difficult to form "undulating" reinforcing ribs on the empty foil area S1 after the electrode 1 is rolled; while when W2 > 10mm, the width of the adhesive 341 is too large, which makes the increase in the force-bearing area of ​​the empty foil area S1 after the electrode 1 is rolled by the roller 3 limited, and the bending resistance is not improved enough, so the electrode tabs in the subsequent die-cutting process are still easy to bend.

[0077] In specific applications, the width W2 of the adhesive component 341 along the circumferential direction of the roller body 2 can be set to any value or a range between any two values, such as 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm.

[0078] like Figure 4 As shown, in some embodiments of this application, the electrode 1 further includes a dispensing area S2 disposed between the empty foil area S1 and the coating area S3, the length of the dispensing area S2 along the first direction X is L1 mm; along the first direction X, the length difference between the first roll-pressed layer 33 and the second roll-pressed layer 34 on any side of the first stepped structure 32a is L2 mm, satisfying: L1 / 4+1≤L2≤L1 / 4+5.

[0079] In this embodiment of the application, by setting the length difference L2 between the first roll layer 33 and the second roll layer 34 on any side of the first step structure 32a within a reasonable range, the roll pressing effect of the first step structure 32a on the empty foil area S1, the dispensing area S2 and the coating area S3 of the electrode 1 can be guaranteed, thereby enabling the foil material in each area of ​​the electrode 1 to be stretched well and ensuring the consistency of the elongation of different areas of the electrode 1.

[0080] It should be noted that, as Figure 3 As shown, in the edge region of the roller body 2, the empty foil area S1 has a dotted adhesive area S2 and a coated area S3 on only one side; in the central region of the roller body 2, the empty foil area S1 has a dotted adhesive area S2 and a coated area S3 on opposite sides; therefore, when the first stepped structure 32a is located in the edge region of the roller body 2, a length difference L2 is formed on the side of the first stepped structure 32a facing the central region of the roller body 2 along the first direction X; when the first stepped structure 32a is located in the central region of the roller body 2, a length difference L2 is formed on both opposite sides of the first stepped structure 32a along the first direction X. In practical applications, any side of the first stepped structure 32a specifically refers to: in the edge region of the roller body 2, it refers to the side of the first stepped structure 32a facing the central region; in the central region of the roller body 2, it refers to any side of the first stepped structure 32a along the first direction X.

[0081] It should be explained that when L2 < L1 / 4 + 1 mm or L2 > L1 / 4 + 5 mm, the first roll layer 33 and the second roll layer 34 cannot simultaneously roll the dispensing area S2 and the coating area S3 effectively, so that the foil of the final electrode 1 cannot be fully stretched.

[0082] In specific applications, the length difference L2 between the first roll-pressed layer 33 and the second roll-pressed layer 34 on any side of the first stepped structure 32a can be set to any value or a range between any two values, such as L1 / 4+1mm, L1 / 4+1.5mm, L1 / 4+2mm, L1 / 4+2.5mm, L1 / 4+3mm, L1 / 4+3.5mm, L1 / 4+4mm, L1 / 4+4.5mm, L1 / 4+5mm.

[0083] Understandably, such as Figure 4 As shown, the length L1 of the dispensing area S2 along the first direction X specifically refers to the length of the dispensing area S2 along the arrangement direction of the empty foil area S1, the dispensing area S2, and the coating area S3. For example, L1 ≥ 5mm. When L1 > 5mm, the tension applied by the ceramic layer at the dispensing area S2 to the foil is relatively large. Therefore, the rolling element 3 needs to roll the dispensing area S2 and the coating area S3 simultaneously to ensure the uniformity of the foil's elongation at the empty foil area S1, the dispensing area S2, and the coating area S3.

[0084] like Figure 4 As shown, in some embodiments of this application, along the first direction X, the length difference between the second roll-pressed layer 34 and the third roll-pressed layer 35 on any side of the second stepped structure 32b is L3mm, which satisfies: 3L1 / 4-5≤L3≤3L1 / 4-1.

[0085] In this embodiment, by setting the length difference L3 between the second roll layer 34 and the third roll layer 35 on any side of the second step structure 32b within a reasonable range, the roll pressing effect of the second step structure 32b on the empty foil area S1, the dispensing area S2 and the coating area S3 of the electrode 1 can be guaranteed, thereby enabling the foil material in each area of ​​the electrode 1 to be stretched well and ensuring the consistency of elongation in different areas of the electrode 1.

[0086] It should be noted that, as Figure 3 As shown, in the edge region of the roller body 2, the empty foil area S1 has a dotted adhesive area S2 and a coated area S3 on only one side; in the central region of the roller body 2, the empty foil area S1 has a dotted adhesive area S2 and a coated area S3 on opposite sides; therefore, when the second stepped structure 32b is located in the edge region of the roller body 2, a length difference L3 is formed on the side of the second stepped structure 32b facing the central region of the roller body 2 along the first direction X; when the second stepped structure 32b is located in the central region of the roller body 2, a length difference L3 is formed on both opposite sides of the second stepped structure 32b along the first direction X. In practical applications, any side of the second stepped structure 32b specifically refers to: in the edge region of the roller body 2, it refers to the side of the second stepped structure 32b facing the central region; in the central region of the roller body 2, it refers to any side of the second stepped structure 32b along the first direction X.

[0087] It should be explained that when L3 < 3L1 / 4-5mm or L3 > 3L1 / 4-1mm, the first roll layer 33 and the second roll layer 34 cannot simultaneously roll the empty foil area S1, the dispensing area S2 and the coating area S3 effectively, so that the foil of the final electrode 1 cannot be fully stretched.

[0088] In specific applications, the length difference L3 between the second roll-pressed layer 34 and the third roll-pressed layer 35 on any side of the second step structure 32b can be set to any value or a range between any two values, such as 3L1 / 4-5mm, 3L1 / 4-4.5mm, 3L1 / 4-4mm, 3L1 / 4-3.5mm, 3L1 / 4-3mm, 3L1 / 4-2.5mm, 3L1 / 4-2mm, 3L1 / 4-1.5mm, 3L1 / 4-1mm.

[0089] like Figure 2As shown, in some embodiments of this application, the rolling device satisfies at least one of the following conditions: A. The thickness of the first rolling layer 33 along the radial direction of the roller body 2 is d1μm, 80≤d1≤160; B. The thickness of the second rolling layer 34 along the radial direction of the roller body 2 is d2μm, 160≤d2≤320; C. The thickness of the third rolling layer 35 along the radial direction of the roller body 2 is d3μm, 80≤d4≤160.

[0090] In this embodiment, by setting the thickness d1 of the first roll-forming layer 33, the thickness d2 of the second roll-forming layer 34, and the thickness d3 of the third roll-forming layer 35 within a reasonable range, it can be ensured that the roll forming member 3 can fully roll the electrode sheet 1 during roll forming. At the same time, the protruding structure 32 formed by the second roll-forming layer 34 can form a distinct "undulating" reinforcing rib structure on the empty foil area of ​​the electrode sheet 1, thereby further improving the bending resistance of the empty foil area S1. In subsequent processing, the electrode tabs formed by the empty foil area S1 are less likely to be bent, thereby improving the product yield. At the same time, it can reduce safety hazards in subsequent processing.

[0091] It should be explained that when the thickness d1 of the first roll-forming layer 33 is less than 80 μm, the rolling strength of the roll forming element 3 on the electrode 1 is insufficient, making the electrode tab formed after final die-cutting prone to collapse. When the thickness d1 of the first roll-forming layer 33 is greater than 160 μm, the roll forming element 3 over-rolls the electrode 1, making the electrode tab formed after final die-cutting prone to warping. When the thickness d2 of the second roll-forming layer 34 is less than 160 μm, the rolling strength of the roll forming element 3 on the electrode 1 is insufficient, making the electrode tab formed after final die-cutting prone to collapse. When the thickness d2 of the second roll-forming layer 34 is greater than 320 μm, the roll forming element 3 over-rolls the electrode 1, making the electrode tab formed after final die-cutting prone to warping. When the thickness d3 of the third roll layer 35 is less than 80 μm, the roll pressing strength of the roll pressing component 3 on the electrode 1 is insufficient, making the electrode tab formed after the final die cutting prone to collapse. When the thickness d3 of the third roll layer 35 is greater than 160 μm, the roll pressing component 3 will over-roll the electrode 1, making the electrode tab formed after the final die cutting prone to warping.

[0092] In specific applications, the thickness d1 of the first roll-pressed layer 33 can be set to any value or a range between any two values, such as 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm.

[0093] The thickness d2 of the second roll-pressed layer 34 can be set to any value or a range between any two values, such as 160μm, 170μm, 180μm, 190μm, 200μm, 30μm, 30μm, 230μm, 240μm, 250μm, 260μm, 270μm, 280μm, 290μm, 300μm, 310μm, 320μm.

[0094] The thickness d3 of the third roll-pressed layer 35 can be set to any value or a range between any two values, such as 80μm, 90μm, 100μm, 110μm, 120μm, 130μm, 140μm, 150μm, 160μm.

[0095] The following specific examples and comparative results illustrate the impact of the corresponding values ​​in the above examples on the battery cell:

[0096] In the actual production process, after the electrode 1 is rolled, the empty foil area S1 on the electrode 1 is die-cut to form an electrode tab. When the rolling effect is poor, the electrode tab will collapse or curl up. Based on this, the quality of the rolling effect is determined by observing whether the die-cut electrode tab deforms.

[0097] In the specific experiment, all other conditions were the same, only the thickness of the different roll-pressed layers was changed.

[0098] Table 1: Thickness Experimental Data

[0099]

[0100] As can be seen from Table 1;

[0101] With other conditions remaining unchanged, if the thickness d1 of the first roll-pressed layer 33 is less than 80 μm, the roll pressing strength of the roll pressing component 3 on the electrode 1 will be insufficient, making the electrode tab formed after the final die-cutting prone to collapse. If the thickness d1 of the first roll-pressed layer 33 is greater than 160 μm, the roll pressing component 3 will over-roll the electrode 1, making the electrode tab formed after the final die-cutting prone to warping.

[0102] With other conditions remaining unchanged, if the thickness d2 of the second roll-pressed layer 34 is less than 160 μm, the roll pressing strength of the roll pressing component 3 on the electrode 1 will be insufficient, making the electrode tab formed after the final die-cutting prone to collapse. If the thickness d2 of the second roll-pressed layer 34 is greater than 320 μm, the roll pressing component 3 will over-roll the electrode 1, making the electrode tab formed after the final die-cutting prone to warping.

[0103] With other conditions remaining unchanged, if the thickness d3 of the third roll layer 35 is less than 80 μm, the roll pressing strength of the roll pressing component 3 on the electrode 1 will be insufficient, making the electrode tab formed after the final die cutting prone to collapse. When the thickness d3 of the third roll pressing layer 35 is greater than 160 μm, the roll pressing component 3 will over-roll the electrode 1, making the electrode tab formed after the final die cutting prone to warping.

[0104] In some embodiments of this application, the second roll-formed layer 34 includes a first adhesive layer 342 and a second adhesive layer 343, wherein the thicknesses of the first adhesive layer 342 and the second adhesive layer 343 are equal, i.e., the thicknesses of the first adhesive layer 342 and the second adhesive layer 343 are between 80 μm and 160 μm. This allows for bonding using the same adhesive member 341, improving convenience.

[0105] In some embodiments of this application, the length of the adhesive 341 along the first direction X is between 40mm and 50mm, thereby ensuring that the protrusion structure 32 formed by the adhesive 341 can extend into the dispensing area S2 during rolling, thus ensuring the rolling effect on the dispensing area S2 and improving the elongation consistency of the electrode 1 after rolling.

[0106] like Figure 5 , Figure 6 , Figure 7 and Figure 8 As shown, in some embodiments of this application, along the radial direction of the roller body 2, the orthographic projection of the protrusion structure 32 on the outer peripheral surface of the second roller section 21 is one or more of the following: S-shape, triangle, quadrilateral, trapezoid.

[0107] In this embodiment, by making the orthographic projection of the protruding structure 32 on the outer peripheral surface of the second roller section 21 in the radial direction of the roller body 2 into one or more combinations of S-shape, triangle, quadrilateral, and trapezoid, the "undulating" reinforcing ribs formed by the roller pressing part 3 after rolling the electrode sheet 1 have different shapes. On the one hand, this improves the aesthetics of the final electrode ear, and on the other hand, it can form different stress areas according to different shapes, thereby increasing the range of bending resistance and allowing for corresponding settings according to different needs.

[0108] In specific applications, the orthographic projection of the protrusion structure 32 on the outer peripheral surface of the second roller section 21 can be one of any regular shapes such as S-shape, triangle, quadrilateral, trapezoid, or rhombus, or a combination of two or more.

[0109] like Figure 1 and Figure 3 As shown, in some embodiments of this application, multiple roller pressing elements 3 are provided, and the multiple roller pressing elements 3 are spaced apart along the first direction X.

[0110] In this embodiment of the application, by arranging multiple rolling elements 3 at intervals along the first direction X, the roller body 2 can simultaneously roll multiple empty foil areas S1 on the electrode 1 when rolling the electrode 1, thereby improving the processing efficiency of the rolling device and thus improving the production efficiency.

[0111] In specific applications, the number of roller pressing elements 3 is matched with the number of empty foil areas S1 on the electrode sheet 1. That is, the number of empty foil areas S1 on the electrode sheet 1 to be rolled is the number of roller pressing elements 3. For example, the number of roller pressing elements 3 can be set to any value such as 1, 2, 3, 4, 5, 6, etc.

[0112] In some embodiments of this application, an electrode processing apparatus is also proposed, which includes a rolling device as described in any of the above embodiments.

[0113] In this embodiment, the rolling device can roll the electrode sheet 1, which has an empty foil area S1 and a coating area S3. The rolling device includes a roller body 2 and a rolling element 3. The roller body 2 includes a first roller section 20 and a second roller section 21 arranged alternately along a first direction X. The first roller section 20 is used to roll the coating area S3 of the electrode sheet. The rolling element 3 is arranged circumferentially around the second roller section 21. The rolling element 3 is used to roll the empty foil area S1 of the electrode sheet 1. The outer circumferential surface of the rolling element 3 has a plurality of protrusions 31, which are spaced apart along the circumferential direction of the roller body 2. Thus, after the rolling element 3 rolls the empty foil area S1 of the electrode sheet 1, a reinforcing rib similar to "undulation" is formed in the empty foil area S1 to improve the bending resistance of the empty foil area S1. In subsequent processing, the electrode tabs formed by the empty foil area S1 are less likely to be bent, thereby improving the product yield. At the same time, it can reduce safety hazards in subsequent processing.

[0114] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0115] Although embodiments of this application have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of this application, the scope of which is defined by the claims and their equivalents.

Claims

1. A rolling device capable of rolling an electrode sheet (1), the electrode sheet (1) having an empty foil area S1 and a coating area S3, characterized in that, include: The roller body (2) and the roller pressing component (3) are provided. The roller body (2) includes a first roller section (20) and a second roller section (21) arranged alternately along a first direction (X). The first roller section (20) is used to roll the coating area S3 of the electrode sheet (1). The roller pressing component (3) is arranged circumferentially around the second roller section (21). The roller (3) is used to roll the empty foil area S1 of the electrode (1); the outer peripheral surface of the roller (3) has a plurality of protrusions (31), and the plurality of protrusions (31) are arranged at intervals along the circumferential direction of the second roller shaft section (21).

2. The roller pressing device according to claim 1, characterized in that, Along the first direction (X), the roller (3) has a stepped structure (32) on at least one side edge, and the stepped structure (32) rolls the boundary position of the empty foil area S1 and the coating area S3 in the electrode (1).

3. The roller pressing device according to claim 2, characterized in that, The roll forming member (3) includes a first roll forming layer (33) and a second roll forming layer (34). The first roll forming layer (33) is connected around the outer peripheral surface of the second roller shaft section (21). The second roll forming layer (34) includes a plurality of adhesive members (341). Along the circumferential direction of the second roller shaft section (21), the plurality of adhesive members (341) are spaced around the first roll forming layer (33) on the side away from the second roller shaft section (21). The adhesive members (341) form the protrusion structure (31). Along the first direction (X), the length of the first roll-formed layer (33) is greater than the length of the second roll-formed layer (34), and the stepped structure (32) includes a first stepped structure (32a) formed between the first roll-formed layer (33) and the second roll-formed layer (34).

4. The roller pressing device according to claim 3, characterized in that, The roll forming member (3) further includes a third roll forming layer (35), which surrounds and covers the second roll forming layer (34) on the side away from the first roll forming layer (33); along the first direction (X), the length of the second roll forming layer (34) is greater than the length of the third roll forming layer (35), and the stepped structure (32) further includes a second stepped structure (32b) formed between the second roll forming layer (34) and the third roll forming layer (35).

5. The roller pressing device according to claim 3, characterized in that, Along the circumferential direction of the roller body (2), the distance between two adjacent adhesive pieces (341) is W1 mm, satisfying: 2≤W1≤10; And / or, the width of the adhesive (341) is W2 mm, satisfying: 2≤W2≤10.

6. The roller pressing device according to claim 4, characterized in that, The electrode (1) further includes a dispensing area S2 disposed between the empty foil area S1 and the coating area S3, wherein the length of the dispensing area S2 along the first direction (X) is L1 mm; Along the first direction (X), the length difference between the first roll-pressed layer (33) and the second roll-pressed layer (34) on any side of the first stepped structure (32a) is L2mm, which satisfies: L1 / 4+1≤L2≤L1 / 4+5; Along the first direction (X), the length difference between the second roll-pressed layer (34) and the third roll-pressed layer (35) on any side of the second stepped structure (32b) is L3mm, which satisfies: 3L1 / 4-5≤L3≤3L1 / 4-1.

7. The roller pressing device according to claim 4, characterized in that, The roller pressing device must satisfy at least one of the following conditions: A. Along the radial direction of the roller body (2), the thickness of the first roll layer (33) is d1μm, 80≤d1≤160; B. Along the radial direction of the roller body (2), the thickness of the second roll layer (34) is d2μm, 160≤d2≤320; C. Along the radial direction of the roller body (2), the thickness of the third roll layer (35) is d3μm, 80≤d4≤160.

8. The roller pressing device according to claim 1, characterized in that, Along the radial direction of the roller body (2), the orthographic projection of the protrusion structure (31) on the outer peripheral surface of the second roller section (21) is one or more of the following: S-shaped, triangular, quadrilateral, and trapezoidal.

9. The roller pressing device according to claim 1, characterized in that, Multiple roller pressing elements (3) are provided, and the multiple roller pressing elements (3) are spaced apart along the first direction (X).

10. An electrode processing device, characterized in that, include: The roller pressing device as described in any one of claims 1-9.

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