Composite pole piece, battery monomer, battery, electric equipment, rolling device and battery manufacturing equipment

Abstract

The utility model discloses a composite pole piece, a battery monomer, a battery, electric equipment, a rolling device and battery manufacturing equipment. The rolling device comprises a first embossing roller and a second embossing roller which are oppositely arranged. Wherein first protrusions are arranged on the roller surface of the first embossing roller, second protrusions are arranged on the roller surface of the second embossing roller, and the first protrusions and the second protrusions are arranged in a staggered mode. The rolling mechanism can increase the surface area of the composite pole piece and improve the reliability of the battery monomer using the composite pole piece.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a composite pole piece, a battery cell, a battery, an electrical device, a rolling device and a battery manufacturing device. 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 the development of battery technology, how to improve battery reliability is a research direction in battery technology. Utility Model Content

[0004] The embodiments of the present application provide a composite pole piece, a battery cell, a battery, an electrical device, a rolling device and a battery manufacturing device, which can effectively improve the reliability of the battery.

[0005] In a first aspect, an embodiment of the present application provides a rolling device, which includes a first embossing roller and a second embossing roller arranged opposite to each other; wherein the roller surface of the first embossing roller is provided with a first protrusion, and the roller surface of the second embossing roller is provided with a second protrusion, and the first protrusion and the second protrusion are staggered.

[0006] In the above technical solution, the roller surface of the first embossing roller is provided with a first protrusion to form a first protrusion on one surface of the composite pole sheet in the thickness direction, and the roller surface of the second embossing roller is provided with a second protrusion to form a second protrusion on the other surface of the composite pole sheet in the thickness direction, so that the surface area on both sides of the composite pole sheet in the thickness direction is increased, and the composite pole sheet with an increased surface area has a larger contact area with the electrolyte, which can improve the reliability of the battery cell.

[0007] In some embodiments, the first protrusions are arranged in multiple rows, and the multiple rows of first protrusions are arranged at intervals along the circumference of the first embossing roller, and each row of the first protrusions includes a plurality of first protrusions arranged at intervals along the axial direction of the first embossing roller; and / or, the second protrusions are arranged in multiple rows, and the multiple rows of second protrusions are arranged at intervals along the circumference of the second embossing roller, and each row of the second protrusions includes a plurality of second protrusions arranged at intervals along the axial direction of the second embossing roller.

[0008] In the above technical solution, the number of the first protrusions and / or the second protrusions arranged per unit area is increased, which can further increase the surface area on both sides of the composite pole piece in the thickness direction.

[0009] In some embodiments, a plurality of first protrusions are provided, the plurality of first protrusions are arranged at intervals along the circumference of the first embossing roller, and each first protrusion extends along the axial direction of the first embossing roller; and / or a plurality of second protrusions are provided, the plurality of second protrusions are arranged at intervals along the circumference of the second embossing roller, and each second protrusion extends along the axial direction of the second embossing roller.

[0010] In the above technical solution, the first protrusion extends along the axial direction of the first embossing roller, which can reduce the difficulty of preparing the first protrusion, thereby reducing the difficulty of preparing the first embossing roller; the second protrusion extends along the axial direction of the second embossing roller, which can reduce the difficulty of preparing the second protrusion, thereby reducing the difficulty of preparing the second embossing roller.

[0011] In some embodiments, the height of the first protrusion protruding from the roller surface of the first embossing roller is H1, satisfying 0um

[0012] In the above technical solution, H1>0um can increase the surface area of ​​the composite electrode, and H1≤100um composite electrode is not easy to crack, and the structural strength is high. Therefore, 0um0um can also increase the surface area of ​​the composite electrode, and H2≤100um composite electrode is not easy to crack, and the structural strength is high. Therefore, 0um<H2≤100um can also take into account both the surface area and structural strength of the composite electrode.<h1>

[0013] In the second aspect, an embodiment of the present application provides a battery manufacturing equipment, which includes a conveying device and a rolling device provided by any of the above embodiments; the conveying device is used to convey the stacked positive electrode sheets, isolation membranes and negative electrode sheets to between the first embossing roller and the second embossing roller.

[0014] In a third aspect, an embodiment of the present application provides a composite pole piece, comprising a stacked positive pole piece, an isolation membrane and a negative pole piece, the composite pole piece having a first surface and a second surface arranged opposite to each other along its thickness direction, the first surface being provided with a first convex portion, the second surface being provided with a first concave portion corresponding to the first convex portion, the second surface being provided with a second convex portion, and the first surface being provided with a second concave portion corresponding to the second convex portion.

[0015] In the above technical solution, the surface area of ​​the composite electrode is increased. The composite electrode of this structure can be used in a battery cell to increase the contact area with the electrolyte, reduce the concentration polarization of ions, thereby slowing down the desorption of lithium and improving the reliability of the battery cell.

[0016] ​In some embodiments, the first protrusions are arranged in multiple rows, and the multiple rows of first protrusions are arranged at intervals along the first direction, and each row of the first protrusions includes a plurality of first protrusions arranged at intervals along the second direction, and the first direction is perpendicular to the second direction; and / or, the second protrusions are arranged in multiple rows, and the multiple rows of second protrusions are arranged at intervals along the first direction, and each row of the second protrusions includes a plurality of second protrusions arranged along the second direction, and the first direction is perpendicular to the second direction.

[0017] In the above technical solution, the number of the first protrusions and / or the second protrusions arranged per unit area increases, and the number of the first grooves and / or the second grooves arranged per unit area increases, which can further increase the surface area on both sides of the composite pole piece in the thickness direction, further increase the contact area with the electrolyte, reduce the concentration polarization of ions, slow down the decomposition of lithium, and improve the reliability of the battery cell.

[0018] In some embodiments, along the second direction, an adjacent row of the first protrusions and an adjacent row of the second protrusions are staggered.

[0019] In the above technical solution, the first convex portion and the second convex portion are staggered in the second direction, and the first convex portion and the second convex portion are more evenly distributed in the second direction, which can improve the consistency of the interface of the composite pole piece.

[0020] In a fourth aspect, an embodiment of the present application provides a battery cell, and the battery cell includes the composite pole piece provided by any of the above embodiments.

[0021] In a fifth aspect, an embodiment of the present application provides a battery, the battery comprising a battery cell provided by any of the above embodiments.

[0022] In a sixth aspect, an embodiment of the present application provides an electrical device, the electrical device comprising a battery cell provided by any of the above embodiments or a battery provided by any of the embodiments, wherein the battery cell or the battery is used to power the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] 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.

[0024] Figure 1 A schematic diagram of the structure of a vehicle according to some embodiments of the present application;

[0025] Figure 2 An exploded schematic diagram of a battery according to some embodiments of the present application;

[0026] Figure 3 An exploded schematic diagram of a battery cell according to some embodiments of the present application;

[0027] Figure 4 This is a schematic diagram of the structure of the electrode assembly of some embodiments of the present application;

[0028] Figure 5 A schematic diagram of the structure of a composite pole piece in some embodiments of the present application;

[0029] Figure 6 It is a schematic diagram of an exploded view of a composite pole piece of some embodiments of the present application;

[0030] Figure 7 It is a cross-sectional view along AA;

[0031] Figure 8 for Figure 7 The enlarged view of point A in the middle;

[0032] Fig. 9 A schematic diagram of the structure of a battery manufacturing device according to some embodiments of the present application;

[0033] Fig.10 A schematic diagram of the structure of a rolling mechanism in some embodiments of the present application;

[0034] Fig.11 for Fig.10 A structural schematic diagram of the middle roller pressing mechanism from another perspective;

[0035] Fig.12 It is a structural schematic diagram of the rolling mechanism of some other embodiments of the present application;

[0036] Fig.13 for Fig.12 The enlarged view of point A in the middle;

[0037] Fig.14 Schematic diagram of the structure of the rolling mechanism of some other embodiments of the present application.

[0038] Icons: 2000-battery manufacturing equipment; 500-conveying device; 510-first conveying mechanism; 520-second conveying mechanism; 530-third conveying mechanism; 540-fourth conveying mechanism; 1000-vehicle; 100-battery; 200-motor; 300-controller; 400-rolling device; 410-first embossing roller; 411-first protrusion; 412-first groove; 420-second embossing roller; 421-second protrusion; 422-second groove; 1-complex Combined electrode sheet; 110-positive electrode sheet; 120-negative electrode sheet; 130-separating film; 111-first surface; 1111-first convex portion; 1112-second concave portion; 121-second surface; 1211-second convex portion; 1222-first concave portion; 10-battery cell; 11-end cover; 12-electrode assembly; 13-shell; 20-box; 21-first part; 22-second part; 23-accommodating space; X-first direction; Y-second direction; Z-thickness direction.

[0039] The drawings are not drawn to scale. DETAILED DESCRIPTION

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] The term "plurality" used in the present application refers to two or more (including two).

[0048] 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.

[0049] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists 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 back and forth between the positive and negative electrodes. The separator is set between the positive and negative electrodes to prevent the positive and negative electrode sheets from short-circuiting, while allowing active ions to pass through.

[0050] 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.

[0051] 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.).

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0057] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are accommodated in the case.

[0058] In some embodiments, multiple battery cells may be first integrated into at least one battery module, and then the battery module may be installed in a box to form a battery pack. In this embodiment, auxiliary structural members such as beams may be provided between the battery modules to improve the installation stability of the battery module in the box.

[0059] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0060] In some embodiments, the battery may be an energy storage device, which includes an energy storage container, an energy storage cabinet, and the like.

[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] Battery cells mainly rely on lithium ions to be intercalated and deintercalated between the positive and negative electrodes to achieve charge and discharge cycles. The electrolyte is a carrier for lithium ion transmission. The slow diffusion of the electrolyte in the active material layer will affect the transmission of lithium ions, resulting in concentration polarization around the negative electrode, lithium ion enrichment, and lithium precipitation, which reduces the reliability of the battery cell.

[0063] In view of this, in order to solve the problem of low reliability of battery cells caused by slow diffusion of electrolyte, the embodiment of the present application provides a technical solution, wherein the rolling device comprises a first embossing roller and a second embossing roller arranged opposite to each other. The roller surface of the first embossing roller is provided with a first protrusion, and the roller surface of the second embossing roller is provided with a second protrusion, and the first protrusion and the second protrusion are arranged in a staggered manner.

[0064] In such a rolling device, the roller surface of the first embossing roller is provided with a first protrusion to form a first protrusion on one surface of the composite pole sheet in the thickness direction, and the roller surface of the second embossing roller is provided with a second protrusion to form a second protrusion on the other surface of the composite pole sheet in the thickness direction, so that the surface area on both sides of the composite pole sheet in the thickness direction is increased to obtain a composite pole sheet with a larger surface area. Such a composite pole sheet has a large contact area with the electrolyte, which can increase the diffusion rate of the electrolyte in the active material layer, reduce the concentration polarization of ions, thereby slowly decomposing lithium and improving the reliability of the battery cell.

[0065] The technical solutions disclosed in the embodiments of the present application are applicable to but not limited to batteries and electrical equipment using batteries.

[0066] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles and spacecrafts, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.

[0067] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0068] Please refer to Figure 1 , Figure 1 1 is a schematic diagram of the structure of a vehicle 1000 according to some embodiments of the present application. A battery 100 is disposed inside the vehicle 1000. The battery 100 may be disposed at the bottom, head, or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may be used as an operating power source for the vehicle 1000.

[0069] The vehicle 1000 may further include a controller 300 and a motor 200 , wherein the controller 300 is used to control the battery 100 to supply power to the motor 200 , for example, to meet the power requirements of starting, navigating, and driving the vehicle 1000 .

[0070] In some embodiments of the present application, the battery 100 can not only serve as an operating power source for the vehicle 1000, but also serve as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0071] In some embodiments, please refer to Figure 2 , Figure 2 The battery 100 of some embodiments of the present application is an exploded schematic diagram, and the battery 100 includes a plurality of battery cells 10. The plurality of battery cells 10 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the plurality of battery cells 10 are connected in series and in parallel.

[0072] In some embodiments, the battery 100 may further include a busbar component (not shown), and the multiple battery cells 10 may be electrically connected via the busbar component to achieve series connection, parallel connection, or mixed connection of the multiple battery cells 10 .

[0073] The busbar component may be a metal conductor, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0074] In some embodiments, the battery 100 may further include a box 20, which is used to accommodate the battery cell 10. The box 20 may include a first portion 21 and a second portion 22, which cover each other to define an accommodating space 23 for accommodating the battery cell 10. Of course, the connection between the first portion 21 and the second portion 22 may be sealed by a sealing element (not shown), which may be a sealing ring, a sealant, etc.

[0075] The first part 21 and the second part 22 may be in various shapes, such as a cuboid, a cylinder, etc. The first part 21 may be a hollow structure with one side open, and the second part 22 may be a hollow structure with one side open, and the open side of the second part 22 covers the open side of the first part 21, thereby forming a box body 20 with a receiving space 23. Of course, the first part 21 may be a hollow structure with one side open, and the second part 22 may be a plate-like structure, and the second part 22 covers the open side of the first part 21, thereby forming a box body 20 with a receiving space 23.

[0076] Please refer to Figure 3 , Figure 3 This is a schematic diagram of an exploded view of a battery cell 10 according to some embodiments of the present application. The battery cell 10 may include a housing 13 , an electrode assembly 12 , an end cover 11 and other functional components.

[0077] The shell 13 is a component for accommodating the electrode assembly 12. The shell 13 can be a hollow structure with an opening at one end, or a hollow structure with openings at both ends. The shell 13 can be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The shell 13 can be in a variety of shapes, such as a cylinder, a cuboid, etc. For example, in Figure 3 In the embodiment, the housing 13 is a rectangular parallelepiped.

[0078] The end cap 11 is a component that covers the opening of the shell 13 to isolate the internal environment of the battery cell 10 from the external environment. The end cap 11 covers the opening of the shell 13, and the end cap 11 and the shell 13 together define a sealed space for accommodating the electrode assembly 12, the electrolyte and other functional components. The shape of the end cap 11 can be adapted to the shape of the shell 13. For example, the shell 13 is a rectangular parallelepiped structure, and the end cap 11 is a rectangular plate structure adapted to the shell 13. For another example, the shell 13 is a cylindrical structure, and the end cap 11 is a circular plate structure adapted to the shell 13. The material of the end cap 11 can also be a variety of materials. For example, the end cap 11 can be a metal material, such as copper, iron, aluminum, steel, aluminum alloy, etc. The material of the end cap 11 can be the same as or different from the material of the shell 13.

[0079] In the battery cell 10, there can be one or two end caps 11. If the shell 13 is a hollow structure with an opening at one end, one end cap 11 is provided accordingly; if the shell 13 is a hollow structure with openings at both ends, two end caps 11 are provided accordingly, and the two end caps 11 cover the two openings of the shell 13 respectively.

[0080] Reference Figure 4 , Figure 4 Schematic diagram of the structure of the electrode assembly 12 of some embodiments of the present application. In some embodiments, the electrode assembly 12 is a laminated structure, and the electrode assembly 12 includes a stacked positive electrode sheet 110 and a negative electrode sheet 120, and a separator 130 is disposed between the positive electrode sheet 110 and the negative electrode sheet 120.

[0081] Of course, in other embodiments, such as Figure 3 As shown, the electrode assembly 12 may also be a wound structure. Winding means that the positive electrode sheet 110, the negative electrode sheet 120 and the separator 130 are stacked and then wound in one direction.

[0082] Figure 5 This is a schematic diagram of the structure of a composite pole piece 1 according to some embodiments of the present application; Figure 6 It is a schematic diagram of an exploded view of a composite pole piece 1 of some embodiments of the present application; Figure 7 It is a cross-sectional view along AA; Figure 8 for Figure 7 Enlarged view of point A in the middle.

[0083] Reference Figure 5 and Figure 6The embodiment of the present application provides a composite electrode sheet 1, which includes a positive electrode sheet 110, a negative electrode sheet 120 and a separator 130 arranged in a stacked manner. It can be understood that the composite electrode sheet 1 is a state in which the positive electrode sheet 110, the separator 130 and the negative electrode sheet 120 are aggregated. If the electrode assembly 12 is a wound structure, the composite electrode sheet 1 is wound in one direction to obtain a wound electrode assembly 12; if the electrode assembly 12 is a laminated structure, the composite electrode sheet 1 is laminated in a thickness direction Z to obtain a laminated electrode assembly 12.

[0084] Reference Figure 7 and Figure 8 , and combined with reference Figure 5 and Figure 6 In some embodiments, the composite electrode sheet 1 includes a stacked positive electrode sheet 110, a separator 130 and a negative electrode sheet 120, and the composite electrode sheet 1 has a first surface 111 and a second surface 121 arranged opposite to each other along its thickness direction Z, the first surface 111 is provided with a first convex portion 1111, the second surface 121 is provided with a first concave portion 1222 corresponding to the first convex portion 1111, the second surface 121 is provided with a second convex portion 1211, and the first surface 111 is provided with a second concave portion 1112 corresponding to the second convex portion 1211.

[0085] Generally, the positive electrode sheet 110 includes a positive current collector and a positive active material layer coated on the surface of the positive current collector, and the negative electrode sheet 120 includes a negative current collector and a negative active material layer coated on the surface of the negative current collector.

[0086] Exemplarily, the first surface 111 may be the side of the positive electrode sheet 110 facing away from the negative electrode sheet 120, and the first surface 111 may also be the side of the negative electrode sheet 120 facing away from the positive electrode sheet 110. Exemplarily, the first surface 111 is the side of the positive electrode sheet 110 facing away from the negative electrode sheet 120, that is, the first surface 111 is the side of the positive electrode active material layer facing away from the negative electrode sheet 120; correspondingly, the second surface 121 is the side of the negative electrode sheet 120 facing away from the positive electrode sheet 110, that is, the second surface 121 is the side of the negative electrode active material layer facing away from the positive electrode sheet 110.

[0087] The first surface 111 is provided with a first convex portion 1111, and the second surface 121 is provided with a first concave portion 1222 corresponding to the first convex portion 1111, which means that along the thickness direction Z of the composite pole piece 1, the first convex portion 1111 corresponds to the first concave portion 1222, that is, the second surface 121 is recessed to form the first concave portion 1222, and the first convex portion 1111 corresponding to the first concave portion 1222 is formed on the first surface 111.

[0088] The shape of the first convex portion 1111 includes but is not limited to a circle, a rectangle, an ellipse, etc.

[0089] The second surface 121 is provided with a second convex portion 1211, and the first surface 111 is provided with a second concave portion 1112 corresponding to the second convex portion 1211, which means that along the thickness direction Z of the composite pole piece 1, the second convex portion 1211 corresponds to the second concave portion 1112, that is, the first surface 111 is recessed to form the second concave portion 1112, and a second convex portion 1211 corresponding to the second concave portion 1112 is formed on the second surface 121.

[0090] The shape of the second convex portion 1211 includes but is not limited to a circle, a rectangle, an ellipse, etc.

[0091] For example, in Figures 5 to 8 In the figure, the first convex portion 1111 and the second convex portion 1211 are rectangular.

[0092] It should be understood that, on the composite pole piece 1 , the first convex portion 1111 and the second convex portion 1211 are staggered and do not overlap, and correspondingly, the first concave portion 1222 and the second concave portion 1112 are also staggered and do not overlap.

[0093] In this embodiment, the first protrusion 1111 and the second recess 1112 increase the surface area of ​​the composite pole piece 1 on the side of the first surface 111, and the second protrusion 1211 and the first recess 1222 increase the surface area of ​​the composite pole piece 1 on the side of the second surface 121, thereby increasing the surface area of ​​the composite pole piece 1. The composite pole piece 1 with this structure can be used in the battery cell 10 to increase the contact area with the electrolyte, reduce the concentration polarization of ions, thereby slowly decomposing lithium and improving the reliability of the battery cell 10.

[0094] In some embodiments, the thickness of the composite pole piece 1 outside the first convex portion 1111 and the second convex portion 1211 is defined as the reference thickness, that is, the reference thickness is the distance between the first surface 111 and the second surface 121. Along the thickness direction Z of the composite pole piece 1, the first convex portion 1111 has a third surface and a fourth surface arranged opposite to each other, and the distance between the third surface and the fourth surface is the first thickness. Along the thickness direction Z of the composite pole piece 1, the second convex portion 1211 has a fifth surface and a sixth surface arranged opposite to each other, and the distance between the fifth surface and the sixth surface is the second thickness. Wherein, the reference thickness is equal to the first thickness and equal to the second thickness.

[0095] It can be understood that in this embodiment, along the thickness direction Z of the composite electrode sheet 1 , the thickness of the stacked positive electrode sheet 110 , the negative electrode sheet 120 and the isolation film 130 are equal everywhere in the composite electrode sheet 1 .

[0096] In some embodiments, the first convex portions 1111 are arranged in multiple rows, and the multiple rows of first convex portions 1111 are arranged at intervals along the first direction X, and each row of first convex portions 1111 includes multiple first convex portions 1111 arranged at intervals along the second direction Y, and the first direction X is perpendicular to the second direction Y. In this way, the number of first convex portions 1111 and first grooves 412 arranged in a unit area increases, which can further increase the surface area on both sides of the thickness direction Z of the composite pole piece 1, further increase the contact area with the electrolyte, reduce the concentration polarization of ions, slow the desorption of lithium, and improve the reliability of the battery cell 10.

[0097] The number of first protrusions 1111 can be set according to the size of the composite pole piece 1, and the first protrusions 1111 can be arranged in two rows, three rows, four rows, five rows, etc. The number of first protrusions 1111 included in each row of first protrusions 1111 can be two, three, four, etc.

[0098] In some embodiments, the second convex portions 1211 are arranged in multiple rows, and the multiple rows of second convex portions 1211 are arranged at intervals along the first direction X. Each row of second convex portions 1211 includes multiple second convex portions 1211 arranged along the second direction Y, and the first direction X is perpendicular to the second direction Y. In this way, the number of second convex portions 1211 and second grooves 422 arranged in a unit area increases, which can further increase the surface area on both sides of the thickness direction Z of the composite pole piece 1, further increase the contact area with the electrolyte, reduce the concentration polarization of ions, slow the desorption of lithium, and improve the reliability of the battery cell 10.

[0099] The number of second protrusions 1211 can be set according to the size of the composite pole piece 1, and the second protrusions 1211 can be arranged in two rows, three rows, four rows, five rows, etc. Each row of second protrusions 1211 can include two, three, four, etc.

[0100] For example, Figure 5 As shown, the first direction X is the length direction of the composite pole piece 1 , and the second direction Y is the width direction of the composite pole piece 1 .

[0101] In some embodiments, along the second direction Y, a row of adjacent first protrusions 1111 and a row of adjacent second protrusions 1211 are staggered.

[0102] The adjacent rows of first convex portions 1111 and second convex portions 1211 are staggered, which means that in the two adjacent rows of convex portions, the center of the first convex portion 1111 is not aligned with the center of the second convex portion 1211 in the second direction Y. In other words, in the first direction X, in the adjacent rows of first convex portions 111 and second convex portions 1211, the projection of the first convex portion 111 in the first direction X only partially overlaps or does not overlap with the projection of the second convex portion 1211 in the first direction X.

[0103] For example, Figure 5 As shown, the projection of the first convex portion 111 in the first direction X does not overlap with the projection of the second convex portion 1211 in the first direction X. It can be understood that in an adjacent row of first convex portions 1111 and a row of second convex portions 1211, along the second direction Y, the second convex portion 1211 is located between two first convex portions 1111, or the second convex portion 1211 is located between two first convex portions 1111, which can improve the consistency of the interface of the composite pole piece 1 and improve the structural strength of the composite pole piece 1.

[0104] In this embodiment, the first protrusion 1111 and the second protrusion 1211 are staggered in the second direction Y. The first protrusion 1111 and the second protrusion 1211 are more evenly distributed in the second direction Y, which can improve the consistency of the interface of the composite pole piece 1 and improve the structural strength of the composite pole piece 1.

[0105] The embodiment of the present application further provides a battery cell 10, and the battery cell 10 includes the composite pole piece 1 provided in any of the above embodiments.

[0106] The embodiment of the present application further provides a battery 100 , and the battery 100 includes the battery cell 10 provided in any of the above embodiments.

[0107] An embodiment of the present application further provides an electrical device, which includes the battery cell 10 provided by any of the above embodiments or the battery 100 provided by any of the embodiments, and the battery cell 10 or the battery 100 is used to supply power to the electrical device.

[0108] Fig. 9 This is a schematic diagram of the structure of a battery manufacturing device 2000 according to some embodiments of the present application. Fig. 9 The embodiment of the present application further provides a battery manufacturing device 2000 , and the battery manufacturing device 2000 includes a conveying device 500 and a rolling device 400 .

[0109] The conveying device 500 includes a first conveying mechanism 510, a second conveying mechanism 520 and a third conveying mechanism 530. The first conveying device 500 is used to convey the positive electrode sheet 110 to the fourth conveying mechanism 540, the second conveying device 500 is used to convey the separator 130 to the fourth conveying mechanism 540, and the third conveying device 500 is used to convey the negative electrode sheet 120 to the fourth conveying mechanism 540. The positive electrode sheet 110, the separator 130 and the negative electrode sheet 120 conveyed to the fourth conveying mechanism 540 are stacked. The fourth conveying mechanism 540 is used to convey the stacked positive electrode sheet 110, the separator 130 and the negative electrode sheet 120 to the rolling device 400.

[0110] The rolling device 400 can be used to prepare the composite electrode sheet 1 . The specific structure of the rolling device 400 is described in detail below.

[0111] Fig.10 A schematic diagram of the structure of a rolling mechanism in some embodiments of the present application; Fig.11 for Fig.10 A structural schematic diagram of the middle roller pressing mechanism from another perspective; Fig.12 It is a structural schematic diagram of the rolling mechanism of some other embodiments of the present application; Fig.13 for Fig.12 The enlarged view of point A in the middle; Fig.14 Schematic diagram of the structure of the rolling mechanism of some other embodiments of the present application.

[0112] The embodiment of the present application provides a rolling device 400, which can be used to roll a composite pole piece 1, wherein the composite pole piece 1 refers to a positive pole piece 110, a separator 130 and a negative pole piece 120 including a stacked and aggregated pole piece.

[0113] Reference Figures 10 to 14 In some embodiments, the rolling device 400 includes a first embossing roller 410 and a second embossing roller 420 that are arranged opposite to each other. The roller surface of the first embossing roller 410 is provided with a first protrusion 411, and the roller surface of the second embossing roller 420 is provided with a second protrusion 421, and the first protrusion 411 and the second protrusion 421 are arranged in a staggered manner.

[0114] Specifically, the first embossing roller 410 may be disposed on the side of the composite pole piece 1 away from the first surface 111, and the second embossing roller 420 may be disposed on the side of the composite pole piece 1 away from the second surface 121. The first embossing roller 410 rolls the composite pole piece 1 to form a first convex portion 1111 on the first surface 111 of the composite pole piece 1, and a first concave portion 1222 on the second surface 121. The second embossing roller 420 rolls the composite pole piece 1 to form a second convex portion 1211 on the second surface 121 of the composite pole piece 1, and a second concave portion 1112 on the first surface 111.

[0115] The first protrusion 411 and the second protrusion 421 are staggered. It can be understood that the first protrusion 411 is rolled out on the composite pole piece 1 to form a first protrusion 1111, and the second protrusion 421 is rolled out on the composite pole piece 1 to form a second protrusion 1211. The first protrusion 1111 and the second protrusion 1211 do not overlap.

[0116] In this embodiment, the roller surface of the first embossing roller 410 is provided with a first protrusion 411 to form a first protrusion 1111 on one surface of the composite pole piece 1 in the thickness direction Z, and the roller surface of the second embossing roller 420 is provided with a second protrusion 421 to form a second protrusion 1211 on the other surface of the composite pole piece 1 in the thickness direction Z, thereby increasing the surface area on both sides of the composite pole piece 1 in the thickness direction Z.

[0117] In addition, the rolling device 400 rolls the composite electrode sheet 1 to form and correspond the positive electrode sheet 110 , the separator 130 , and the negative electrode sheet 120 at one time, thereby improving production efficiency.

[0118] Reference Fig.10 and Fig.11 In some embodiments, the first protrusions 411 are arranged in multiple rows, and the multiple rows of first protrusions 411 are arranged at intervals along the circumference of the first embossing roller 410, and each row of first protrusions 411 includes multiple first protrusions 411 arranged at intervals along the axial direction of the first embossing roller 410. In this arrangement, the number of first protrusions 411 arranged per unit area increases, which can further increase the surface area on both sides of the thickness direction Z of the composite pole piece 1.

[0119] It can be understood that the first protrusion 411 is a bump, and the shape of the first protrusion 411 includes but is not limited to a circle, a rectangle, an ellipse, etc. Fig.10 In the embodiment, the first protrusion 411 is rectangular, so that the composite pole piece 1 forms a rectangular first protrusion 1111 and a rectangular first concave portion 1222. The first protrusions 411 can be arranged in two rows, three rows, four rows, etc. Each row of the first protrusions 411 can be provided with two, three, four or even more first protrusions 411. For example, in Fig.11 In the embodiment, the first protrusions 411 are arranged in twelve rows, and each row of the first protrusions 411 is arranged with twenty first protrusions 411 .

[0120] Reference Fig.10 and Fig.11 In some embodiments, the second protrusions 421 are arranged in multiple rows, and the multiple rows of second protrusions 421 are arranged at intervals along the circumference of the second embossing roller 420, and each row of second protrusions 421 includes multiple second protrusions 421 arranged at intervals along the axial direction of the second embossing roller 420. In this arrangement, the number of second protrusions 421 arranged per unit area increases, which can further increase the surface area on both sides of the thickness direction Z of the composite pole piece 1.

[0121] It can be understood that the second protrusion 421 is a bump, and the shape of the second protrusion 421 includes but is not limited to a circle, a rectangle, an ellipse, etc. Fig.10 In the embodiment, the second protrusions 421 are rectangular, so that the composite pole piece 1 forms a rectangular second protrusion 1211 and a rectangular second concave portion 1112. The second protrusions 421 can be arranged in two rows, three rows, four rows, etc. Each row of the second protrusions 421 can be provided with two, three, four or even more first protrusions 411. For example, in Fig.11 In the embodiment, the second protrusions 421 are arranged in twelve rows, and each row of the second protrusions 421 is arranged with twenty second protrusions 421 .

[0122] Reference Fig.12 and Fig.13In some embodiments, the first protrusions 411 are closely arranged in a field shape, and a first groove 412 is formed between two adjacent first protrusions 411, and the first groove 412 is for the second protrusion 421 to be inserted into.

[0123] In some embodiments, along the axial direction of the first embossing roller 410 , the first protrusions 411 and the second protrusions 421 are staggered.

[0124] Reference Fig.14 In some embodiments, a plurality of first protrusions 411 are provided, and the plurality of first protrusions 411 are arranged at intervals along the circumference of the first embossing roller 410 , and each first protrusion 411 extends along the axial direction of the first embossing roller 410 .

[0125] Each first protrusion 411 extends along the axial direction of the first embossing roller 410. It can be understood that in this embodiment, the first protrusion 411 is in the shape of an elongated strip.

[0126] The first protrusions 411 extend along the axial direction of the first embossing roller 410 , which can reduce the difficulty of preparing the first protrusions 411 , thereby reducing the difficulty of preparing the first embossing roller 410 .

[0127] Reference Fig.14 In some embodiments, a plurality of second protrusions 421 are provided, and the plurality of second protrusions 421 are arranged at intervals along the circumference of the second embossing roller 420 , and each second protrusion 421 extends along the axial direction of the second embossing roller 420 .

[0128] Each second protrusion 421 extends along the axial direction of the second embossing roller 420. It can be understood that in this embodiment, the second protrusion 421 is in the shape of an elongated strip.

[0129] The second protrusions 421 extend along the axial direction of the second embossing roller 420 , which can reduce the difficulty of preparing the second protrusions 421 , thereby reducing the difficulty of preparing the second embossing roller 420 .

[0130] Reference Fig.11 , Fig.12 , Fig.13 and Fig.14 Correspondingly, a first groove 412 is formed between two adjacent first protrusions 411 , and the first groove 412 can be inserted into the second protrusion 421 . A second groove 422 is formed between two adjacent first protrusions 411 , and the second groove 422 can be inserted into the first protrusion 411 .

[0131] Reference Fig.11 In some embodiments, the height of the first protrusion 411 protruding from the roller surface of the first embossing roller 410 is H1, which satisfies 0um

[0132] ​Exemplarily, H1 may be 1 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm. It should be understood that since it is impossible to list all values ​​between 0 um and 100 um, several intermediate values ​​are listed as examples. It can be understood that all values ​​between these values ​​can be used as the height of the first protrusion 411 protruding from the roller surface of the first embossing roller 410 as H1.

[0133] The height of the first protrusion 411 protruding from the roller surface of the first embossing roller 410 refers to the dimension of the first protrusion 411 protruding from the roller surface of the first embossing roller 410 along the radial direction of the first embossing roller 410 .

[0134] Reference Fig.11 In some embodiments, the height of the first protrusion 411 protruding from the roller surface of the first embossing roller 410 is H2, satisfying 0um<H2≤100um.

[0135] H1>0um can increase the surface area of ​​the composite pole piece 1 , and H1≤100um makes the composite pole piece 1 not easy to crack, and the structural strength of the composite pole piece 1 is relatively high. Therefore, 0um

[0136] Exemplarily, H2 may be 1 mm, 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, or 100 mm. It should be understood that since it is impossible to list all values ​​between 0 um and 100 um, several intermediate values ​​are listed as examples. It can be understood that all values ​​between these values ​​can be used as the height of the second protrusion 421 protruding from the roller surface of the second embossing roller 420 as H2.

[0137] The height of the second protrusions 421 protruding from the roller surface of the second embossing roller 420 refers to the dimension of the second protrusions 421 protruding from the roller surface of the second embossing roller 420 along the radial direction of the second embossing roller 420 .

[0138] H2>0um can increase the surface area of ​​the composite pole piece 1 , and H2≤100um makes the composite pole piece 1 not easy to crack and has a higher structural strength. Therefore, 0um<H2≤100um can take into account both the surface area and structural strength of the composite pole piece 1 .

[0139] ​The embodiment of the present application also provides a rolling device 400, which includes a first embossing roller 410 and a second embossing roller 420 arranged opposite to each other. The roller surface of the first embossing roller 410 is provided with a first protrusion 411, and the roller surface of the second embossing roller 420 is provided with a second protrusion 421, and the first protrusion 411 and the second protrusion 421 are arranged in a staggered manner. The first protrusion 411 is provided in multiple rows, and the multiple rows of first protrusions 411 are arranged at intervals along the circumference of the first embossing roller 410, and each row of first protrusions 411 includes multiple first protrusions 411 arranged at intervals along the axial direction of the first embossing roller 410; the second protrusion 421 is provided in multiple rows, and the multiple rows of second protrusions 421 are arranged at intervals along the circumference of the second embossing roller 420, and each row of second protrusions 421 includes multiple second protrusions 421 arranged at intervals along the axial direction of the second embossing roller 420.

[0140] The embodiment of the present application also provides a composite electrode sheet 1, comprising a stacked positive electrode sheet 110, a separator 130 and a negative electrode sheet 120, the composite electrode sheet 1 having a first surface 111 and a second surface 121 arranged opposite to each other along its thickness direction Z, the first surface 111 being provided with a first convex portion 1111, the second surface 121 being provided with a first concave portion 1222 corresponding to the first convex portion 1111, the second surface 121 being provided with a second convex portion 1211, and the first surface 111 being provided with a second concave portion 1112 corresponding to the second convex portion 1211. The first convex portions 1111 are provided in multiple rows, the multiple rows of the first convex portions 1111 are arranged at intervals along the first direction X, each row of the first convex portions 1111 includes multiple first convex portions 1111 arranged at intervals along the second direction Y, and the first direction X is perpendicular to the second direction Y. The second convex portions 1211 are arranged in multiple rows, and the multiple rows of second convex portions 1211 are arranged at intervals along the first direction X. Each row of second convex portions 1211 includes multiple second convex portions 1211 arranged along the second direction Y. The first direction X is perpendicular to the second direction Y. Along the second direction Y, adjacent rows of first convex portions 1111 and adjacent rows of second convex portions 1211 are staggered.

[0141] 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.

[0142] The above embodiments are only used to illustrate the technical solutions 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 modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A rolling device, characterized in that: The rolling device comprises a first embossing roller and a second embossing roller which are arranged opposite to each other; The roller surface of the first embossing roller is provided with a first protrusion, the roller surface of the second embossing roller is provided with a second protrusion, and the first protrusion and the second protrusion are staggered.

2. The rolling device according to claim 1, characterized in that: The first protrusions are arranged in multiple rows, the multiple rows of the first protrusions are arranged at intervals along the circumference of the first embossing roller, and each row of the first protrusions includes a plurality of the first protrusions arranged at intervals along the axial direction of the first embossing roller; and / or, The second protrusions are arranged in a plurality of rows, the plurality of rows of the second protrusions are arranged at intervals along the circumference of the second embossing roller, and each row of the second protrusions includes a plurality of the second protrusions arranged at intervals along the axial direction of the second embossing roller.

3. The rolling device according to claim 1, characterized in that: There are a plurality of the first protrusions, the plurality of the first protrusions are arranged at intervals along the circumference of the first embossing roller, and each of the first protrusions extends along the axial direction of the first embossing roller; and / or, A plurality of the second protrusions are provided, and the plurality of the second protrusions are arranged at intervals along the circumference of the second embossing roller, and each of the second protrusions extends along the axial direction of the second embossing roller.

4. The rolling device according to any one of claims 1 to 3, characterized in that: The height of the first protrusion protruding from the roller surface of the first embossing roller is H1, which satisfies 0um<H1≤100um; and / or, The height of the first protrusion protruding from the roller surface of the first embossing roller is H2, which satisfies 0um<H2≤100um.

5. A battery manufacturing device, characterized in that: include: The rolling device according to any one of claims 1 to 4; The conveying device is used to convey the stacked positive electrode sheet, the separator and the negative electrode sheet to between the first embossing roller and the second embossing roller.

6. A composite pole piece, characterized in that: The composite electrode sheet comprises a positive electrode sheet, an isolation film and a negative electrode sheet which are stacked together. The composite electrode sheet has a first surface and a second surface which are arranged opposite to each other along the thickness direction thereof. The first surface is provided with a first convex portion, the second surface is provided with a first concave portion corresponding to the first convex portion, the second surface is provided with a second convex portion, and the first surface is provided with a second concave portion corresponding to the second convex portion.

7. The composite pole piece according to claim 6, characterized in that: The first convex portions are arranged in multiple rows, the multiple rows of the first convex portions are arranged at intervals along a first direction, each row of the first convex portions includes multiple first convex portions arranged at intervals along a second direction, and the first direction is perpendicular to the second direction; and / or, The second protrusions are arranged in multiple rows, and the multiple rows of second protrusions are arranged at intervals along the first direction. Each row of the second protrusions includes a plurality of second protrusions arranged along the second direction, and the first direction is perpendicular to the second direction.

8. The composite pole piece according to claim 7, characterized in that: Along the second direction, an adjacent row of the first protrusions and an adjacent row of the second protrusions are staggered.

9. A battery cell, characterized in that: A composite pole piece comprising any one of claims 6 to 8.

10. A battery, characterized in that: Comprising the battery cell according to claim 9.

11. An electrical device, characterized in that: The invention comprises the battery cell according to claim 9 or the battery according to claim 10, wherein the battery cell or the battery is used to supply power to the electrical device.

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