Rolling device and battery manufacturing equipment

Abstract

The utility model discloses a rolling device and battery manufacturing equipment, the rolling device is used for rolling a pole piece, the pole piece comprises a film coating area and a pole lug, the rolling device comprises a pair of rollers, each roller comprises a working section, a chamfering section and a non-working section which are arranged in the axial direction of the roller, the diameter of the working section is larger than or equal to that of the non-working section, and the chamfering section is arranged on the working section. The chamfering section is connected with the working section and the non-working section; the chamfering section comprises a first end connected with the working section and a second end connected with the non-working section, and the diameter of the chamfering section is gradually reduced from the first end to the second end. The working section and the chamfering section are used for rolling a film coating area, and the non-working section is used for keeping tabs empty. The pole piece rolled by the rolling device is used in the battery monomer, so that the reliability of the battery monomer can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to a rolling device and battery manufacturing equipment. Background Art

[0002] With the development of new energy technology, batteries are being used more and more widely. Batteries have high energy density, high safety, long service life, and are green and environmentally friendly to the social environment. They have been widely used in passenger cars, commercial vehicles, electric bicycles, heavy trucks, energy storage facilities, battery swap stations, engineering manufacturing, smart equipment, etc. At the same time, they also promote technical development and research in communications, medical equipment, energy development, etc.

[0003] In battery technology, how to improve the reliability of battery cells is a technical problem that needs to be solved urgently. Utility Model Content

[0004] The embodiments of the present application provide a rolling device and a battery manufacturing equipment, which can effectively improve the reliability of battery cells.

[0005] In a first aspect, an embodiment of the present application provides a rolling device, which is used to roll a pole piece, wherein the pole piece includes a coating area and a pole ear, and the rolling device includes a pair of rollers; each of the rollers includes a working section, a chamfering section, and a non-working section arranged along its axial direction, the diameter of the working section is greater than or equal to the diameter of the non-working section, and the chamfering section connects the working section and the non-working section; the chamfering section includes a first end connected to the working section and a second end connected to the non-working section, and the diameter of the chamfering section gradually decreases from the first end to the second end; the working section and the chamfering section are used to roll the coating area, and the non-working section is used to avoid the pole ear.

[0006] In the above technical solution, the chamfered section corresponds to the edge of the coating area. By arranging the chamfered section at the position of the roller corresponding to the edge of the coating area, the chamfered section can reduce the rolling force of the roller on the thinning area and reduce the thinning degree of the edge of the coating area, thereby alleviating the thickness difference between the edge and the middle of the coating area, especially when the middle part of the roller is deformed, the thickness difference between the edge and the middle of the coating area is alleviated, thereby improving the reliability of the battery cell using the pole piece.

[0007] In some embodiments, the chamfered section is a body of revolution, and the generatrix of the chamfered section is a curve or a straight line.

[0008] In the above technical solution, the chamfering section is a rotating body to facilitate the preparation of the chamfering section and reduce the difficulty of preparing the roller. The generatrix of the chamfering section is a curve or a straight line to alleviate the stress concentration caused by the rolling coating area of ​​the chamfering section.

[0009] In some embodiments, the generatrix of the chamfered section is an outwardly convex arc.

[0010] In the above technical solution, the generatrix of the chamfered section is an outwardly convex arc line, which can further alleviate the stress concentration caused by the roller coating area of ​​the chamfered section.

[0011] In some embodiments, along the axial direction of the roller, the size of the chamfered section is L, satisfying 0mm<L≤30mm.

[0012] In the above technical scheme, 0mm<L can alleviate the thickness difference between the edge and the middle of the coating area; L≤30mm can reduce the size requirement of the chamfered section in the axial direction of the roller, thereby obtaining a chamfered section with a shorter size in the axial direction; therefore, 0mm<L≤30mm, the size of the chamfered section in the axial direction of the roller is appropriate, which can alleviate the thickness difference between the edge and the middle of the coating area, and take into account the size requirement of the roller.

[0013] In some embodiments, a difference between a diameter of the first end and a diameter of the second end is Δφ, satisfying 0um<Δφ≤60um.

[0014] In the above technical scheme, 0um<△φ, so that the diameter of the second end is smaller than the diameter of the first end, so that the rolling force of the chamfer section on the edge of the coating area is reduced, and the edge of the coating area will not be rolled too thin; △φ≤60um, so that the difference between the diameter of the first end and the diameter of the second end will not be too small, and the chamfer section can exert a rolling force on the edge of the coating area, thereby alleviating the risk of insufficient compaction density at the edge of the coating area due to the chamfer section not rolling to the edge of the coating area; therefore, 0um<△φ≤60um, can take into account the thickness difference between the edge and the middle of the coating area and the compaction density of the edge of the coating area, and take into account the reliability and energy density of the battery cell.

[0015] In some embodiments, the roller surface of the chamfered section transitions to the roller surface of the working section in a circular arc; and / or, the roller surface of the chamfered section transitions to the roller surface of the non-working section in a circular arc.

[0016] In the above technical solution, the circular arc transition between the roller surface of the chamfered section and the roller surface of the working section can relieve stress concentration, and the circular arc transition between the roller surface of the chamfered section and the roller surface of the non-working section can relieve stress concentration.

[0017] In some embodiments, the diameter of the first end is equal to the diameter of the working section; and / or the diameter of the second end is equal to the diameter of the non-working section.

[0018] In the above technical solution, the difficulty of preparing the first chamfered section can be reduced, thereby reducing the difficulty of preparing the rolling roller.

[0019] In some embodiments, both ends of the roller in the axial direction are the non-working sections.

[0020] In the above technical solution, it is convenient for the roller to roll the pole piece with pole ears at both ends, thereby improving the compatibility of the roller.

[0021] In some embodiments, there are multiple working sections and multiple non-working sections, the non-working sections and the working sections are alternately arranged along the axial direction of the roller, and adjacent working sections and non-working sections are connected by the chamfered sections.

[0022] In the above technical solution, the compatibility of the rolling device can be further improved. The rolling device can be used to roll pole pieces with larger sizes in the axial direction of the roller, so that the pole piece is divided into multiple sub-pole pieces, which greatly improves the production efficiency of the pole piece.

[0023] In a second aspect, an embodiment of the present application further provides a battery manufacturing device, wherein the battery includes the above-mentioned rolling device. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 This is a schematic diagram of the structure of the pole piece of some embodiments of the present application;

[0026] Figure 2 For some embodiments of this application Figure 1 The cross-sectional view along AA is a pole piece rolled by the rolling device before improvement;

[0027] Figure 3 For other embodiments of this application Figure 1 The cross-sectional view along AA is a pole piece rolled out by the improved rolling device;

[0028] Figure 4 A schematic diagram of a rolling device for rolling pole pieces in some embodiments of the present application;

[0029] Figure 5 A schematic diagram of the structure of a rolling device in some embodiments of the present application;

[0030] Figure 6 A schematic diagram of the structure of a roller in some embodiments of the present application;

[0031] Figure 7 Schematic diagram of the structure of rollers in other embodiments of the present application;

[0032] Figure 8The schematic diagrams of the structures of rollers in some other embodiments of the present application;

[0033] Fig. 9 A schematic diagram of the structure of rollers in some other embodiments of the present application;

[0034] Fig.10 Schematic diagram of the structure of rollers in some further embodiments of the present application.

[0035] Icon: 100-Roller pressing device;

[0036] 10-roller; 11-working section; 12-non-working section; 13-chamfering section; 131-first end; 132-second end;

[0037] A-first gap; B-second gap;

[0038] P-axial;

[0039] 200-pole piece;

[0040] 21- coating area; 211- edge; 212- middle;

[0041] 22-ear;

[0042] X-width direction;

[0043] Z-thickness direction.

[0044] The drawings are not drawn to scale. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0046] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0047] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0048] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] In the description of the present application, it should be noted that, unless otherwise specified, "multiple" means more than two; the terms "upper", "lower", "left", "right", "inside", "outside", etc., indicating the orientation or positional relationship, are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. "Vertical" is not strictly vertical, but is within the allowable error range. "Parallel" is not strictly parallel, but is within the allowable error range.

[0050] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0051] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0052] The term "plurality" used in the present application refers to two or more (including two).

[0053] In the present application, battery cells may include but are not limited to lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries or magnesium-ion batteries, etc. Battery cells include but are not limited to cylinders, flat bodies, rectangular parallelepipeds or other shapes, etc. Battery cells generally include cylindrical battery cells, square battery cells and soft-pack battery cells, etc., according to the packaging method.

[0054] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. Metal ions (such as lithium ions) are embedded and removed between the positive electrode and the negative electrode. The separator is set between the positive electrode and the negative electrode to prevent the positive electrode sheet and the negative electrode sheet from short-circuiting, while allowing active ions to pass through.

[0055] The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as a positive electrode ear.

[0056] Taking lithium-ion batteries as an example, the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The positive electrode collector can be a metal foil or a composite current collector. For example, as a metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The composite current collector may include a polymer material base and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0057] The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as a negative electrode tab.

[0058] The negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with silver-plated surface, stainless steel with silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The negative electrode active material may be carbon or silicon, etc.

[0059] In order to ensure that a large current can pass without melting, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the isolation film can be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly can be a wound structure or a laminated structure.

[0060] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can reduce the impact of liquid or other foreign matter on the charging or discharging of the battery cells.

[0061] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0062] The electrode sheet includes a coating area and a tab, wherein the coating area refers to the area where the active material layer is located. Since the active material layer has fluidity, after the active material layer is coated on the current collector and dried, the coating area will be thin at the edge (thinning area) and thick in the middle, that is, there is a thickness difference between the edge and the middle of the coating area.

[0063] In the battery production process, rollers are usually used to roll pole pieces to increase the compaction density of the pole pieces and thus increase the energy density of the battery cell. In the related art, although rolling pole pieces with rollers can increase the compaction density of the pole pieces, the middle part of the roller will be deformed by deflection under the interaction force between the middle part of the roller and the middle part of the coating area, which makes the rolling force of the roller on the middle part of the coating area smaller, and the rolling force of the roller on the edge of the coating area increases, making the edge of the coating area thinner, resulting in an increase in the thickness difference between the edge and the middle of the coating area. The rolled pole pieces are used in battery cells. The gap corresponding to the edges of the coating areas of two adjacent pole pieces is large, the ion transmission distance is long, the insufficient power performance of the battery cell causes lithium precipitation, and the reliability of the battery cell is reduced.

[0064] In view of this, in order to solve the problem that the thickness difference between the edge and the middle of the coating area aggravated by the rolling of the pole piece by the roller, resulting in reduced battery reliability, an embodiment of the present application provides a rolling device, which is used to roll the pole piece, and the pole piece includes a coating area and a pole ear. The rolling device includes a pair of rollers, and each roller includes a working section, a chamfering section, and a non-working section arranged in sequence. The chamfering section includes a first end connected to the working section and a second end connected to the non-working section. From the first end to the second end, the diameter of the chamfering section gradually decreases, and the working section and the chamfering section are used to roll the coating area.

[0065] By setting a chamfered section at the position of the roller corresponding to the edge of the coating area, the rolling force of the chamfered section on the thinning area can be reduced. The chamfer can be reduced to reduce the degree of thinning of the edge of the coating area by the roller, thereby alleviating the thickness difference between the edge and the middle of the coating area, especially when the middle part of the roller is deformed, thereby improving the reliability of the battery cell using the pole piece.

[0066] The technical solution disclosed in the embodiments of the present application is applicable to rolling pole pieces.

[0067] Figure 1 It is a schematic diagram of the structure of the pole piece 200 of some embodiments of the present application; Figure 2 For other embodiments of this application Figure 1 The cross-sectional view along AA shows the pole piece 200 rolled out before the rolling device 100 is improved.

[0068] Reference Figure 1 to Figure 2 The pole piece 200 includes a coating area 21 and a pole ear 22 disposed on at least one side of the width direction X of the pole piece 200. The coating area 21 refers to the area formed after the active material layer is coated on the collector and dried. The active material layer has fluidity, and the edge 211 of the coating area 21 of the pole piece 200 after drying is thinned, and the thickness of the edge 211 of the coating area 21 is less than the thickness of the middle 212 of the coating area 21.

[0069] The pole piece 200 may have active material layers on both sides of the thickness direction Z to form a coating area 21 , or the pole piece 200 may have a coating area 21 on one side of the thickness direction Z and an empty foil area on the other side.

[0070] The electrode sheet 200 may include two tabs 22, namely a positive tab 22 and a negative tab 22. The positive tab 22 and the negative tab 22 may be on the same side or on different sides. Figure 1 As shown, two pole ears 22 are arranged on both sides of the width direction X of the pole piece 200 .

[0071] The pole piece 200 provided in the embodiment of the present application may be a positive pole piece 200 or a negative pole piece 200 .

[0072] The embodiment of the present application provides a rolling device 100, which can alleviate the thickness difference between the edge 211 and the middle 212 of the coating area 21 of the pole piece 200, and improve the reliability of the battery cell using the pole piece 200. The specific structure of the rolling device 100 is described in detail below.

[0073] Figure 3 For some embodiments of this application Figure 1 The cross-sectional view along AA is a pole piece 200 rolled out after the roller pressing device is improved; Figure 4Schematic diagram of a rolling device 100 rolling a pole piece 200 according to some embodiments of the present application; Figure 5 It is a structural schematic diagram of a rolling device 100 of some embodiments of the present application; Figure 6 It is a schematic structural diagram of a roller 10 in some embodiments of the present application; Figure 7 Schematic diagram of the structure of the roller 10 according to other embodiments of the present application.

[0074] Reference Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 The embodiment of the present application provides a rolling device 100 , which is used for rolling a pole piece 200 .

[0075] In some embodiments, the rolling device 100 includes a pair of rollers 10, each roller 10 includes a working section 11, a chamfering section 13, and a non-working section 12 arranged along its axial direction P, the diameter of the working section 11 is greater than or equal to the diameter of the non-working section 12, the chamfering section 13 connects the working section 11 and the non-working section 12; the chamfering section 13 includes a first end 131 connected to the working section 11 and a second end 132 connected to the non-working section 12, and the diameter of the chamfering section 13 gradually decreases from the first end 131 to the second end 132. The working section 11 and the chamfering section 13 are used to roll the coating area 21, and the non-working section 12 is used to avoid the empty pole ear 22.

[0076] The working section 11 refers to the area where the rolling force is applied to the pole piece 200. The roller surface of the working section 11 is in contact with the pole piece 200 and participates in the rolling of the pole piece 200. The non-working section 12 refers to the area where no rolling force is applied to the pole piece 200. The roller surface of the non-working section 12 does not contact the pole piece 200 and does not participate in the rolling of the pole piece 200. The non-working section 12 can reduce the risk of deformation or cracking of the pole ear 22.

[0077] The diameter of the working section 11 may be larger than the diameter of the non-working section 12 (e.g. Figure 6 The diameter of the working section 11 may also be equal to the diameter of the non-working section 12 (as shown in FIG. Figure 7 As shown). It should be noted that, since the thickness of the pole ear 22 is less than the thickness of the pole piece 200 in the coating area 21, there is a thickness difference between the pole ear 22 and the coating area 21. Therefore, when the diameter of the working section 11 is equal to the diameter of the non-working section 12, the non-working section 12 will not contact the pole ear 22, and the purpose of avoiding the pole ear 22 can be achieved. Of course, when the diameter of the working section 11 is greater than the diameter of the non-working section 12, the avoidance effect can be further improved.

[0078] The chamfer section 13 is a transition area between the working section 11 and the non-working section 12, wherein the chamfer section 13 also applies a rolling force to the pole piece 200, and the chamfer section 13 participates in the rolling of the pole piece 200. The diameter of the chamfer section 13 gradually decreases, and the chamfer section 13 is a step formed between the working section 11 and the non-working section 12.

[0079] The working section 11 and the chamfering section 13 are used to roll the coating area 21. The working section 11 corresponds to the middle 212 of the coating area 21 to meet the compaction density of the middle 212 of the coating area 21. The chamfering section 13 corresponds to the edge 211 of the coating area 21 to meet the compaction density of the edge 211 of the coating area 21. Figure 5 As shown, a first gap A is formed between the working sections 11 of a pair of rollers 10, and a second gap B is formed between the chamfered sections 13 of a pair of rollers 10. The first gap A corresponds to the middle 212 of the coating area 21, and the second gap B corresponds to the edge 211 of the coating area 21. It should be noted that although the roller surface of the chamfered section 13 is not coplanar with the roller surface of the working area, the roller 10 is deformed by deflection under the interaction force between the roller 10 and the pole piece 200, so that the chamfered section 13 can roll the edge 211 of the coating area 21, and the working section 11 can roll the middle 212 of the coating area 21.

[0080] Compared with the rolling force applied by the working section 11 to the middle 212 of the coating area 21, the rolling force applied by the chamfering section 13 to the edge 211 of the coating area 21 is smaller, so that after the rolling device 100 rolls the electrode 200, the edge 211 of the coating area 21 will not be too thin, and the thickness difference between the middle 212 of the coating area 21 and the edge 211 will not be aggravated. In this way, the thickness difference between the edge 211 of the coating area 21 and the middle 212 of the coating area 21 can even be reduced by 10um (e.g. Figure 2 ) is improved to 2um (such as Figure 3 ).

[0081] In this embodiment, the chamfered section 13 corresponds to the edge 211 of the coating area 21. By setting the chamfered section 13 at the position of the roller 10 corresponding to the edge 211 of the coating area 21, the chamfered section 13 can reduce the rolling force of the roller 10 on the thinning area, and reduce the degree of thinning of the edge 211 of the coating area 21, thereby alleviating the thickness difference between the edge 211 and the middle part 212 of the coating area 21, especially when the middle part 212 of the roller 10 is deformed, the thickness difference between the edge 211 and the middle part 212 of the coating area 21 is alleviated, thereby improving the reliability of the battery cell using the pole piece 200.

[0082] Reference Figure 6 and Figure 8 , Figure 8 Schematic diagram of the structure of the roller 10 in some other embodiments of the present application. In some embodiments, the chamfered section 13 is a body of revolution, and the generatrix of the chamfered section 13 is a curve or a straight line.

[0083] The chamfered section 13 is a rotating body, which facilitates the preparation of the chamfered section 13 and can reduce the difficulty of preparing the roller 10. The generatrix of the chamfered section 13 is a curve or a straight line to alleviate the stress concentration caused by the chamfered section 13 rolling the coating area 21.

[0084] In some embodiments, the generatrix of the chamfered section 13 is an outwardly convex arc. The generatrix of the chamfered section 13 being an outwardly convex arc can further alleviate the stress concentration caused by the chamfered section 13 rolling the coating area 21 .

[0085] Of course, in other embodiments, the generatrix of the chamfered section 13 may also be a concave arc.

[0086] Reference Figure 6 In some embodiments, along the axial direction P of the roller 10, the size of the chamfered section 13 is L, satisfying 0mm<L≤30mm.

[0087] For example, L can be 0.2 mm, 2 mm, 4 mm, 7 mm, 10 mm, 12 mm, 14 mm, 15 mm, 20 mm, 22 mm, 25 mm, 27 mm, 29 mm, 30 mm, etc. Since it is impossible to list all the values ​​between 0 and 30, several intermediate values ​​are listed here as examples, and it can be understood that any value between these values ​​can be used as the size L of the chamfered section 13.

[0088] In this embodiment, 0mm<L can alleviate the thickness difference between the edge 211 and the middle 212 of the coating area 21; L≤30mm can reduce the size requirement of the chamfered section 13 in the axial direction P of the roller 10, thereby obtaining a chamfered section 13 with a shorter size in the axial direction P; therefore, 0mm<L≤30mm, the size of the chamfered section 13 in the axial direction P of the roller 10 is appropriate, which can alleviate the thickness difference between the edge 211 and the middle 212 of the coating area 21, while taking into account the size requirement of the roller 10.

[0089] Continue to refer to Figure 6 In some embodiments, the difference between the diameter of the first end 131 and the diameter of the second end 132 is Δφ, which satisfies 0um<Δφ≤60um. It should be noted that, for the convenience of description, Figure 6 Δφ / 2, ie, the difference between the radius of the first end 131 and the radius of the second end 132, is illustrated in FIG.

[0090] For example, Δφ may be 0 mm, 14 mm, 17 mm, 20 mm, 24 mm, 27 mm, 30 mm, 34 mm, 37 mm, 40 mm, 44 mm, 47 mm, 50 mm, 54 mm, 57 mm, 60 mm, etc. Since it is impossible to list all values ​​between 0 and 60, several intermediate values ​​are listed here as examples. It can be understood that any value between these values ​​can be used as the difference between the diameter of the first end 131 and the diameter of the second end 132 as Δφ.

[0091] In this embodiment, 0um<△φ, so that the diameter of the second end 132 is smaller than the diameter of the first end 131, so that the rolling force of the chamfer section 13 on the edge 211 of the coating area 21 is reduced, and the edge 211 of the coating area 21 will not be rolled too thin; △φ≤60um, so that the difference between the diameter of the first end 131 and the diameter of the second end 132 will not be too small, and the chamfer section 13 can exert a rolling force on the edge 211 of the coating area 21, thereby alleviating the risk of insufficient compaction density of the edge 211 of the coating area 21 due to the chamfer section 13 not rolling to the edge 211 of the coating area 21; therefore, 0um<△φ≤60um can take into account the thickness difference between the edge 211 and the middle 212 of the coating area 21 and the compaction density of the edge 211 of the coating area 21, and take into account the reliability and energy density of the battery cell.

[0092] Reference Fig. 9 , Fig. 9 Schematic diagram of the structure of the roller 10 according to some other embodiments of the present application.

[0093] Reference Fig. 9 In some embodiments, the roller surface of the chamfered section 13 transitions to the roller surface of the working section 11 in an arc shape. The arc shape transition between the roller surface of the chamfered section 13 and the roller surface of the working section 11 can alleviate stress concentration.

[0094] Reference Fig. 9 In some embodiments, the roller surface of the chamfered section 13 transitions to the roller surface of the non-working section 12 in an arc shape. The arc shape transition between the roller surface of the chamfered section 13 and the roller surface of the non-working section 12 can alleviate stress concentration.

[0095] Of course, the roller surface of the chamfering section 13 and the roller surface of the working section 11 may not have an arc transition, as shown in FIG. Figure 6 In some embodiments, the diameter of the first end 131 is equal to the diameter of the working section 11. In this way, there is no step between the first end 131 of the chamfered section 13 and the working section 11.

[0096] Of course, the roller surface of the chamfered section 13 and the roller surface of the non-working section 12 may not have an arc transition. In some embodiments, the diameter of the second end 132 is equal to the diameter of the non-working section 12. In this way, there is no step between the second end 132 of the chamfered section 13 and the non-working section 12.

[0097] The diameter of the first end 131 is equal to the diameter of the working section 11 , and / or the diameter of the second end 132 is equal to the diameter of the non-working section 12 , which can reduce the difficulty of preparing the first chamfered section 13 , thereby reducing the difficulty of preparing the roller 10 .

[0098] Reference Figures 6 to 9 In some embodiments, both ends of the roller 10 in the axial direction P are non-working sections 12 .

[0099] In this embodiment, the two ends of the roller 10 in the axial direction P are non-working sections 12, which facilitates the roller 10 to roll the pole piece 200 with pole ears 22 at both ends of the width direction X of the pole piece 200, thereby improving the compatibility of the roller 10 and improving production efficiency.

[0100] In other embodiments, a non-working section 12 may be provided at one end of the roller 10 in the axial direction P, and not provided at the other end. In this case, the roller 10 is suitable for rolling a pole piece 200 with a pole ear 22 provided on one side.

[0101] Reference Fig.10 , Fig.10 The schematic diagram of the structure of the roller 10 of some other embodiments of the present application is shown in FIG. In some embodiments, a plurality of working segments 11 are provided, a plurality of non-working segments 12 are provided, the non-working segments 12 and the working segments 11 are alternately arranged along the axial direction P of the roller 10, and adjacent working segments 11 and non-working segments 12 are connected by chamfered segments 13.

[0102] There are two, three, four, etc. working sections 11, and there are two, three, four, etc. non-working sections 12. The number of working sections 11 and the number of non-working sections 12 may be the same or different. For example, Fig.10 As shown, two working sections 11 are provided, and three non-working sections 12 are provided. The non-working sections 12 and the working sections 11 are alternately arranged along the axial direction P of the roller 10. Adjacent working sections 11 and non-working sections 12 are connected by chamfered sections 13. The roller 10 is used to roll wider pole pieces 200. The rolled pole pieces 200 can be cut into two pieces after being cut, that is, one pole piece 200 can be cut into two sub-pole pieces.

[0103] There are multiple working sections 11 and multiple non-working sections 12, which can further improve the compatibility of the rolling device 100. The rolling device 100 can be used to roll pole pieces 200 with larger sizes in the axial direction P of the roller 10, so that the pole piece 200 is divided into multiple sub-pole pieces 200, which greatly improves the production efficiency of the pole piece 200.

[0104] The embodiment of the present application also provides a battery manufacturing device, and the battery includes the above-mentioned rolling device 100.

[0105] Reference Figure 6 , the embodiment of the present application further provides a rolling device 100, the rolling device 100 is used to roll the pole piece 200, and the pole piece 200 includes a coating area 21 and a pole ear 22. The rolling device 100 includes a pair of rollers 10, each roller 10 includes a working section 11, a chamfering section 13, a non-working section 12, a chamfering section 13, a working section 11, a chamfering section 13 and a non-working section 12 arranged along its axial direction P. The diameter of the working section 11 is greater than the diameter of the non-working section 12, and the adjacent working sections 11 and non-working sections 12 are connected by the chamfering section 13. The chamfering section 13 includes a first end 131 connected to the working section 11 and a second end 132 connected to the non-working section 12, and the diameter of the chamfering section 13 gradually decreases from the first end 131 to the second end 132. The working section 11 and the chamfering section 13 are used to roll the coating area 21, and the non-working section 12 is used to avoid the pole ear 22. The chamfered section 13 is a rotating body, the generatrix of the chamfered section 13 is a straight line, the diameter of the first end 131 is equal to the diameter of the working section 11, the diameter of the second end 132 is equal to the diameter of the non-working section 12, and the two ends of the roller 10 in its axial direction P are non-working sections 12.

[0106] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0107] The above embodiments are only used to illustrate the technical solution of the present application and are not used to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A rolling device for rolling a pole piece, wherein the pole piece comprises a coating area and a pole ear, characterized in that: The rolling device comprises a pair of rollers; Each of the rollers comprises a working section, a chamfering section and a non-working section arranged along its axial direction, the diameter of the working section is greater than or equal to the diameter of the non-working section, and the chamfering section connects the working section and the non-working section; The chamfered section comprises a first end connected to the working section and a second end connected to the non-working section, and the diameter of the chamfered section gradually decreases from the first end to the second end; The working section and the chamfering section are used for rolling the coating area, and the non-working section is used for avoiding the pole ear.

2. The rolling device according to claim 1, characterized in that: The chamfered section is a body of revolution, and the generatrix of the chamfered section is a curve or a straight line.

3. The rolling device according to claim 2, characterized in that: The generatrix of the chamfered section is an outwardly convex arc.

4. The rolling device according to any one of claims 1 to 3, characterized in that: Along the axial direction of the roller, the size of the chamfered section is L, which satisfies 0mm<L≤30mm.

5. The rolling device according to any one of claims 1 to 3, characterized in that: A difference between a diameter of the first end and a diameter of the second end is Δφ, which satisfies 0um<Δφ≤60um.

6. The rolling device according to any one of claims 1 to 3, characterized in that: The roller surface of the chamfered section and the roller surface of the working section have an arc transition; and / or, The roller surface of the chamfered section and the roller surface of the non-working section are in circular arc transition.

7. The rolling device according to any one of claims 1 to 3, characterized in that: The diameter of the first end is equal to the diameter of the working section; and / or, The diameter of the second end is equal to the diameter of the non-working section.

8. The rolling device according to any one of claims 1 to 3, characterized in that: The two ends of the roller in the axial direction are the non-working sections.

9. The rolling device according to any one of claims 1 to 3, characterized in that: There are a plurality of working sections and a plurality of non-working sections, the non-working sections and the working sections are alternately arranged along the axial direction of the roller, and adjacent working sections and non-working sections are connected via the chamfered sections.

10. A battery manufacturing device, characterized in that: The invention comprises the rolling device as described in any one of claims 1 to 9.

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