Battery cells, battery devices, manufacturing equipment, energy storage systems and electrical devices

Abstract

The present application relates to the field of battery technology. The present application discloses a battery cell, a battery device, a manufacturing device, an energy storage system and an electrical device. The battery cell includes: a shell and an electrode assembly. The electrode assembly is arranged in the shell. The electrode assembly includes: a first diaphragm and a first pole piece stacked in a first direction, and the first diaphragm is connected to the same end of the first pole piece in a second direction. The end of the first diaphragm connected to the first pole piece protrudes from the first pole piece in the second direction, and the first diaphragm is suitable for driving the first pole piece to be wound to the winding needle when the first diaphragm is rolled up to the winding needle. The first direction is orthogonal to the second direction. Therefore, by connecting the first diaphragm to one end of the length of the first pole piece, the first pole piece can be pulled to be wound to the winding needle during the process of winding the first diaphragm to the winding needle, so as to improve the winding efficiency, thereby improving the production efficiency of the electrode assembly and the battery cell.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, a manufacturing device, an energy storage system and an electrical device. Background Art

[0002] In the related art, the wound electrode assembly is mainly composed of an anode electrode sheet, a cathode electrode sheet and a separator, which are stacked and wound. However, during the winding process, the anode electrode sheet and the cathode electrode sheet need to be inserted and fed separately, and there is an insertion and feeding action, which leads to low production efficiency of the winding core. Summary of the invention

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a battery cell, which can realize synchronous rolling of the pole piece and the separator, thereby improving the production efficiency of the battery cell.

[0004] The present application also provides a battery device having the battery cell.

[0005] The present application further proposes a manufacturing device for the above-mentioned battery cell.

[0006] The present application further proposes an energy storage system using the above battery device.

[0007] The present application further proposes an electrical device using the above energy storage system.

[0008] In the first aspect, the present application proposes a battery cell, comprising: a shell and an electrode assembly, the electrode assembly is arranged in the shell, the electrode assembly comprises: a first diaphragm and a first pole sheet stacked in a first direction, and the first diaphragm is connected to the first pole sheet at the same end in the second direction, the end of the first diaphragm connected to the first pole sheet protrudes out of the first pole sheet in the second direction, and the first diaphragm is suitable for driving the first pole sheet to be wound onto a winding needle when rolling up to a winding needle, and the first direction is orthogonal to the second direction.

[0009] According to the battery cell of the embodiment of the present application, by connecting the first diaphragm to one end of the length of the first pole piece, the first pole piece can be pulled and wound onto the winding needle during the process of winding the first diaphragm onto the winding needle, thereby improving the winding efficiency and further improving the production efficiency of the electrode assembly and the battery cell.

[0010] According to some embodiments of the present application, the electrode assembly also includes: a second diaphragm and a second electrode sheet stacked in the first direction, the first diaphragm and the second diaphragm are located on both sides of the first electrode sheet in the first direction, and the second diaphragm and the second electrode sheet are connected to the same end in the second direction, an end of the second diaphragm connected to the second electrode sheet protrudes out of the second electrode sheet in the second direction, and the second diaphragm is suitable for driving the second electrode sheet to be wound onto the winding needle when rolling up to the winding needle.

[0011] In the above technical solution, the second diaphragm is connected to one end of the length of the second pole piece, so that when the second diaphragm is wound onto the winding needle, the second pole piece can be pulled and wound onto the winding needle, thereby improving the winding efficiency and further improving the production efficiency of the electrode assembly and the battery cell.

[0012] According to some embodiments of the present application, the second diaphragm is connected to the same end of the first pole piece in the second direction, so that when the first diaphragm is rolled up to the winding needle, the first pole piece, the second diaphragm and the second pole piece are sequentially driven to be wound up to the winding needle.

[0013] In the above technical scheme, when the diaphragm and the electrode sheet are wound by the winding needle, the first diaphragm is wound preferentially, and during the rolling of the first diaphragm, the first electrode sheet and the second diaphragm can be driven synchronously, and the second diaphragm pulls the second electrode sheet to be wound to the winding needle. During the winding process of the electrode assembly, the feeding action of the first electrode sheet, the feeding action of the second electrode sheet and the feeding action of the second diaphragm can be omitted, thereby improving the winding efficiency and improving the processing efficiency of the electrode assembly.

[0014] According to some embodiments of the present application, a first connection region is provided between the first diaphragm and the first pole piece, and in the second direction, a first interval is provided between the first connection region and an adjacent end portion of the first pole piece, and a size of the first interval is 5 mm to 10 mm.

[0015] In the above technical solution, the distance between the first connection area and the end of the first electrode sheet can be made more reasonable, thereby improving the reliability and safety of the electrode assembly. At the same time, the size of the air avoidance area (ie, the first gap) is smaller, which can also reduce the cost of the electrode assembly.

[0016] According to some embodiments of the present application, the length dimension of the first connection area is 30 mm to 100 mm.

[0017] In the above technical solution, the length of the first connection area is not less than 30 mm, which can make the connection stability and reliability between the first pole piece and the first diaphragm higher, and the length of the first connection area does not exceed 100 mm. While taking into account the connection stability and reliability between the first pole piece and the first diaphragm, it can prevent the length of the first connection area from being too long, thereby reducing the difficulty of connecting the first pole piece and the first diaphragm and further improving the processing efficiency of the electrode assembly.

[0018] According to some embodiments of the present application, a second connection region is provided between the second pole piece and the second diaphragm, and in the second direction, a second interval is provided between the second connection region and an adjacent end portion of the first pole piece, and a size of the second interval is 5 mm to 10 mm.

[0019] In the above technical scheme, on the one hand, the gap between the end area of ​​the first pole piece and the second diaphragm, the second diaphragm and the second pole piece after winding can be made smaller, so as to avoid the thickness of the end area of ​​the first pole piece becoming larger due to the setting of the glue layer, so as to reduce the gap in the end area of ​​the first pole piece after the electrode assembly is in the blanking state, thereby reducing the probability of diaphragm breakage; on the other hand, there are burrs in the end area of ​​the first pole piece, and the second pole piece is connected to the second diaphragm in this area. The burrs may pierce the second diaphragm, resulting in a short circuit between the first pole piece and the second pole piece. Therefore, setting a second interval between the second connection area and the end of the first pole piece can reduce the probability of short circuit in the electrode assembly and further improve the safety and reliability of the electrode assembly.

[0020] According to some embodiments of the present application, the first connection region at least partially overlaps with the second connection region.

[0021] In the above technical solution, in the embodiment where the first connection area overlaps with the second connection area, the size of the air avoidance area is smaller in the winding direction of the electrode assembly, which can make the gap consistency of the electrode assembly after being in the unloading state better. In the embodiment where the first connection area at least partially overlaps with the second connection area, the bonding accuracy requirements for the first connection area and the second connection area are lower, the processing difficulty is lower, and the processing efficiency is higher.

[0022] According to some embodiments of the present application, the length dimension of the second connection area is 30 mm to 100 mm.

[0023] In the above technical solution, the length of the second connection area is not less than 30 mm, which can make the connection stability and reliability between the second pole piece and the second diaphragm higher, and the length of the second connection area does not exceed 100 mm. While taking into account the connection stability and reliability between the second pole piece and the second diaphragm, it can prevent the length of the second connection area from being too long, thereby reducing the difficulty of connecting the second pole piece and the second diaphragm and further improving the processing efficiency of the electrode assembly.

[0024] According to some embodiments of the present application, the second pole piece includes a plurality of sub-pole pieces, which are arranged sequentially in the second direction, and after the electrode assembly is wound, the projected contours in the direction of the winding axis are such that some of the sub-pole pieces are formed into arc contours, and some of the sub-pole pieces are formed into annular contours.

[0025] In the above technical solution, at least a portion of the second pole piece can be constructed as a stacked structure, which is beneficial to improving the consistency of the interlayer gap in the corner area (hereinafter referred to as the bending area) of the electrode assembly in the blanking state, and can reduce the probability of cracking of the outer ring pole piece, thereby improving the safety and reliability of the electrode assembly.

[0026] According to some embodiments of the present application, the sub-pole piece defining an annular contour is connected to the first diaphragm and the second diaphragm.

[0027] According to some embodiments of the present application, the length of the sub-pole sheet defining the arc-shaped contour gradually increases in a direction away from the winding axis of the electrode assembly.

[0028] In the above technical solution, as the winding needle is wound, the outer diameter of the electrode assembly wound on the winding needle gradually increases, so that the length of the sub-pole piece with the arc-shaped contour relatively located on the radial outside is greater than the length of the sub-pole piece with the arc-shaped contour relatively located on the radial inside, so that the effective area of ​​the electrode assembly after processing is larger (the area where the first pole piece and the second pole piece are opposite to each other on both sides of a second diaphragm is defined as the effective area, and the area where only the first pole piece or only the second pole piece is arranged in a certain area is defined as the invalid area), and the energy density of the electrode assembly is higher.

[0029] According to some embodiments of the present application, after the electrode assembly is cut, the electrode assembly defines a main body area and bending areas located on both sides of the main body area, and at least one end of the sub-pole piece with an arc-shaped contour is located in the main body area.

[0030] In the above technical scheme, after the electrode assembly is cut, the electrode assembly will be further extruded in the radial direction and deformed into the oblong or runway-shaped outline as shown in the figure, and the two ends of the electrode assembly are formed into bending areas, and the middle area corresponds to the area where the large surface of the battery cell of the battery cell is located, forming the main body area, so that at least one end of the sub-pole piece with an arc-shaped outline in the wound state has a projected outline in the cut state located within the straight line edge defined by the main body area, that is, located in the area where the large surface of the battery cell is located, which can improve the interlayer gap in the bending area at one end of the electrode assembly, improve the consistency of the interlayer gap in the bending area, and at the same time reduce the stress concentration problem in the bending area, so as to reduce the probability of cracking of the outer ring pole piece and improve the reliability and stability of the electrode assembly.

[0031] In a second aspect, an embodiment of the present application provides a battery device, including: a battery cell in the above embodiment, the battery cell is used to store or provide electrical energy.

[0032] In the third aspect, an embodiment of the present application provides a manufacturing device for a battery cell, comprising: a winding needle, which is used to wind the electrode assembly of the battery cell in the above embodiment, and the winding needle is constructed as a vacuum adsorption winding needle, the end of the first diaphragm protrudes the first pole piece in the second direction, and the protruding length C1 and the outer circumferential length C2 of the winding needle satisfy: 0.25C2≤C1≤0.75C2.

[0033] In a fourth aspect, an embodiment of the present application provides an energy storage system, comprising: a power conversion device and the battery device in the above embodiment, wherein the power conversion device is used to electrically connect the power generation device and the energy storage device.

[0034] In a fifth aspect, an embodiment of the present application provides an electrical device, including: a battery device or an energy storage system in the above embodiments, wherein the battery device or the energy storage device is used to store or provide electrical energy.

[0035] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0037] Figure 1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0038] Figure 2 is a schematic diagram of a battery device according to an embodiment of the present application;

[0039] Figure 3 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0040] Figure 4 is a schematic diagram of the cooperation between the electrode assembly and the winding needle according to the first embodiment of the present application;

[0041] Figure 5 is a schematic diagram of an electrode assembly in a blanking state according to the first embodiment of the present application;

[0042] Figure 6 yes Figure 5 The middle circle shows a partial enlarged schematic diagram of area A;

[0043] Figure 7 is a schematic diagram of the cooperation between the electrode assembly and the winding needle according to the second embodiment of the present application;

[0044] Figure 8 is a schematic diagram of an electrode assembly in a blanking state according to a second embodiment of the present application;

[0045] Fig. 9 is a schematic diagram of a sub-pole piece according to an embodiment of the present application;

[0046] Fig.10 is a schematic diagram of another sub-pole piece according to an embodiment of the present application;

[0047] Fig.11 It is a schematic diagram of the cooperation between the electrode assembly and the winding needle in the prior art;

[0048] Fig.12 It is a schematic diagram of an electrode assembly in the prior art in a blanking state;

[0049] Fig.13 is a schematic diagram of an energy storage system according to an embodiment of the present application.

[0050] Reference numerals:

[0051] This application:

[0052] The electrode assembly 100,

[0053] A first diaphragm 10, a first pole piece 20, a second diaphragm 30, a second pole piece 40, a sub-pole piece 41,

[0054] first connection area a, first interval b, second connection area c, second interval d, main area e, bending area f,

[0055] Winding needle 200, battery cell 300, battery device 400, power device 500, controller 600, motor 700, box 800, energy storage system 900,

[0056] Shell 310, end cover 320,

[0057] Power generation equipment 910, power conversion equipment 920;

[0058] Existing technology:

[0059] Electrode assembly 100'

[0060] The first diaphragm 10', the first pole piece 20', the second diaphragm 30', the second pole piece 40', and the clamping winding needle 200'. DETAILED DESCRIPTION

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0068] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0069] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0070] The term “plurality” used in this application refers to two or more (including two).

[0071] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0072] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0073] At present, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric cars, electric vehicles, as well as assembly, aerospace and other fields. As the application fields of batteries continue to expand, their market demand is also constantly expanding.

[0074] The battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged.

[0075] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0076] The battery apparatus mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include multiple battery cells, which are connected in series, in parallel or in mixed connection through a busbar component.

[0077] In some embodiments, a battery cell assembly is generally formed by arranging a plurality of battery cells.

[0078] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module may be formed by bundling a plurality of battery cells by a cable tie.

[0079] In some embodiments, the battery device may be a battery pack, which includes a case and one or more battery cell assemblies, wherein the battery cell assemblies are accommodated in the case.

[0080] As an example, the battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box by fixing the battery module in the box.

[0081] As an example, the battery cell assembly may also be housed in the case by directly fixing a plurality of battery cells to the case.

[0082] As an example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0083] 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.

[0084] The embodiment of the present application provides an energy storage device, including one or more battery clusters (Battery Cluster) to increase the voltage and capacity of the energy storage device. The battery cluster may include multiple battery devices, and the multiple battery devices are connected in series through a busbar component to increase the voltage of the energy storage device. When the energy storage device includes multiple battery clusters, the multiple battery clusters are connected in parallel to increase the capacity of the energy storage device.

[0085] The energy storage device can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems or temporary power supply systems. The energy storage device can store electrical energy as needed and output electrical energy at an appropriate time. For example, the energy storage device can store electrical energy during low power consumption and provide electrical energy to relevant users or electrical equipment during peak power consumption. The energy storage system provided in the embodiment of the present application can be any power system that requires the use of an energy storage device.

[0086] In some embodiments, the energy storage device is an energy storage container or an energy storage cabinet.

[0087] In some embodiments, the energy storage device may include a cabinet and one or more battery clusters, wherein the battery clusters are housed in the cabinet.

[0088] The technical solutions described in the embodiments of the present application are applicable to battery devices and electrical devices using the battery devices.

[0089] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0090] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0091] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application. A battery is provided inside the vehicle, and the battery can be provided at the bottom, head, or tail of the vehicle. The battery can be used to power the vehicle, for example, the battery can be used as an operating power source for the vehicle.

[0092] The vehicle may further include a controller 600 and a motor 700 . The controller 600 is used to control the battery device 400 to supply power to the motor 700 . The motor 700 serves as a load, for example, to meet the power requirements for starting, navigating and driving the vehicle.

[0093] In some embodiments of the present application, the battery device 400 can not only be used as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0094] Please refer to Figure 2 , Figure 2 An exploded view of a battery provided in some embodiments of the present application. The battery device 400 includes a battery cell and a box 800, and the box 800 is used to accommodate the battery cell (ie, a battery module).

[0095] Among them, the box body 800 is a component for accommodating the battery unit. The box body 800 provides a placement space for multiple battery cells 300 in the battery unit. The box body 800 can adopt a variety of structures. In some embodiments, the box body 800 may include a tray and a box body 800, and the tray and the box body 800 cover each other to define a placement space for accommodating the battery cells 300. The tray and the box body 800 can be in a variety of shapes, such as a cuboid, a cylinder, etc. The tray can be a hollow structure with one side open, and the box body 800 can also be a hollow structure with one side open. The open side of the box body 800 covers the open side of the tray, so as to form a box body 800 with a placement space. It can also be that the tray is a hollow structure with one side open, and the box body 800 is a plate-like structure. The box body 800 covers the open side of the tray, so as to form a box body 800 with a placement space. As an example, the battery cell 300 may be a cylindrical battery cell 300 , a prismatic battery cell 300 , or a battery cell 300 of other shapes, which is not particularly limited in the present application.

[0096] In the battery device 400, there can be one or more battery cells 300. If there are more than one battery cell 300, the battery cells 300 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the battery cells 300 are both connected in series and in parallel. The battery cells 300 can be connected in series, in parallel, or in mixed connection to form a battery unit, and then the battery units are connected in series, in parallel, or in mixed connection to form a whole, and are contained in the box 800. All the battery cells 300 can also be directly connected in series, in parallel, or in mixed connection, and then the whole formed by all the battery cells 300 is contained in the box 800.

[0097] The battery cell 300 is the smallest energy unit of the battery unit or the battery device 400. The battery unit or the battery device 400 includes a plurality of battery cells 300. The battery cell 300 includes a shell, an end cover, and an electrode assembly 100 disposed in the shell.

[0098] like Figure 3As shown, the battery cell 300 includes: a shell 310, an end cover 320 and an electrode assembly 100. The shell 310 may include a bottom plate and a side plate. The side plate is arranged around the bottom plate and defines a receiving space with a mounting opening. The electrode assembly 100 and other functional components can be arranged in the receiving space. The end cover 320 covers the mounting opening of the shell 310 to isolate the internal environment of the battery cell 300 from the external environment. The shape of the end cover 320 is compatible with the shape of the shell 310. The end cover 320 can be supported by a material with a certain hardness and strength (such as aluminum alloy, carbon fiber plate), and the end cover can effectively protect the safety and reliability of the internal components of the shell 310 during extrusion and collision.

[0099] In some embodiments, the end cap 320 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 300 reaches a threshold value. The material of the end cap 320 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member may also be provided on the inner side of the end cap 320, and the insulating member may be used to isolate the electrical connection components in the housing 310 from the end cap 320 to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, etc.

[0100] The housing 310 is a component used to cooperate with the end cap 320 to form an internal environment of the battery cell 300, wherein the formed internal environment can be used to accommodate the electrode assembly 100, the electrolyte and other components. The housing 310 and the end cap 320 can be independent components, and a mounting opening can be set on the housing 310, and the internal environment of the battery cell 300 is formed by covering the opening with the end cap 320 at the mounting opening.

[0101] The shell 310 can be in various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism shape, etc. Specifically, the shape of the shell 310 can be determined according to the specific shape and size of the electrode assembly 100. The shell 310 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0102] The electrode assembly 100 is a component in the battery cell 300 where electrochemical reactions occur. One or more electrode assemblies 100 may be included in the housing 310. The electrode assembly 100 is mainly formed by winding or stacking an anode electrode sheet and a cathode electrode sheet, and a diaphragm is usually provided between the anode electrode sheet and the cathode electrode sheet. The portion of the anode electrode sheet and the cathode electrode sheet with active materials constitutes the main body of the electrode assembly 100, and the portion of the anode electrode sheet and the cathode electrode sheet without active materials each constitutes a tab. The anode tab and the cathode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the anode active material and the cathode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0103] In the prior art, during the winding process of the cathode electrode sheet, anode electrode sheet and diaphragm of the wound electrode assembly 100, after the diaphragm is rolled up, the anode electrode sheet and the cathode electrode sheet need to be inserted and fed separately, and the insertion and feeding action is required, which reduces the production efficiency of the electrode assembly 100.

[0104] Based on this, the present application proposes an electrode assembly 100 , in which the electrode sheet and the diaphragm can be rolled up synchronously, eliminating the insertion and feeding action, thereby improving the production efficiency of the electrode assembly 100 .

[0105] Reference below Figure 1-Figure 13 An electrode assembly 100 , a battery cell 300 , a battery, and an electric device 500 according to an embodiment of the present application are described.

[0106] See also Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 as well as Figure 8 As shown, the present application proposes a battery cell 300 , including a housing 310 , an electrode assembly 100 , and an end cover 320 .

[0107] Among them, the electrode assembly 100 includes: a first diaphragm 10 and a first electrode sheet 20 stacked in a first direction, and the first diaphragm 10 is connected to the first electrode sheet 20 at the same end in the second direction, and the end of one end of the first diaphragm 10 connected to the first electrode sheet 20 protrudes from the first electrode sheet 20 in the second direction, and the first diaphragm 10 is suitable for driving the first electrode sheet 20 to be wound to the winding needle 200 when it is rolled up to the winding needle 200, and the first direction is orthogonal to the second direction.

[0108] It should be noted that the first direction is the stacking direction of the electrode assembly 100 . Before the electrode assembly 100 is wound or cut, the first direction is the thickness direction of the electrode assembly 100 , and the second direction is the length direction of the electrode assembly 100 .

[0109] It should be pointed out that, combined with Figure 4 and Figure 5 As shown, or combined Figure 7 and Figure 8 As shown, during the processing of the electrode assembly 100 of the embodiment of the present application, it is necessary to be wound by the winding needle 200. During the processing, the electrode assembly 100 is in Figure 4 and Figure 7 The winding state shown in the figure, when the electrode assembly 100 is wound to the required thickness, the electrode assembly 100 needs to be removed from the winding needle 200. At this time, the electrode assembly 100 is switched to the unloading position, and the electrode assembly 100 at the unloading position is further compressed and deformed to Figure 5 and Figure 8 As shown in the unloading state, the electrode assembly 100 has an unwinding state and a unwinding state, and the electrode assembly 100 in the unwinding state is wound on the axis of the winding needle 200, and the radial, circumferential and axial directions defined in the present application are defined based on the electrode assembly 100 being in the unwinding state, and the first direction and the second direction are defined based on the direction when the electrode assembly 100 is laid flat before being in the unwinding state.

[0110] Specifically, the present application bonds the first diaphragm 10 and the first pole piece 20 at the same end in the length direction so that the first pole piece 20 and the first diaphragm 10 can be formed into a composite part, and during the rolling process of the winding needle 200, one length end of the first diaphragm 10 can be connected to the winding needle 200, and as the first diaphragm 10 is rolled up, the first pole piece 20 connected to the first diaphragm 10 is synchronously driven to be wound onto the winding needle 200 successively or synchronously.

[0111] It is understandable that the above bonding can be achieved directly by providing a glue coating layer, or by other physical means to achieve the connection between the electrode and the diaphragm without changing the physical and chemical properties of the electrode and the diaphragm.

[0112] That is to say, when the diaphragm and the electrode sheet are wound by the winding needle 200, the first diaphragm 10 is wound up first. During the rolling process of the first diaphragm 10, the portion of the first diaphragm 10 protruding from the first electrode sheet 20 at one end of the length can be wound onto the winding needle 200 first, and the first electrode sheet 20 can be synchronously pulled and wound onto the winding needle 200. During the winding process of the electrode assembly 100, the insertion and feeding action of the first electrode sheet 20 can be omitted, thereby improving the winding efficiency, thereby improving the processing efficiency of the electrode assembly 100.

[0113] According to the battery cell 300 of the embodiment of the present application, the first diaphragm 10 is connected to one length end of the first pole piece 20, so that when the first diaphragm 10 is wound onto the winding needle 200, the first pole piece 20 can be pulled and wound onto the winding needle 200, so as to improve the winding efficiency, thereby improving the production efficiency of the electrode assembly 100 and the battery cell 300.

[0114] According to some embodiments of the present application, the electrode assembly 100 also includes: a second diaphragm 30 and a second electrode sheet 40 stacked in a first direction, the first diaphragm 10 and the second diaphragm 30 are located on both sides of the first electrode sheet 20 in the first direction, and the second diaphragm 30 and the second electrode sheet 40 are connected at the same end in the second direction, the end of one end of the second diaphragm 30 connected to the second electrode sheet 40 protrudes out of the second electrode sheet 40 in the second direction, and the second diaphragm 30 is suitable for driving the second electrode sheet 40 to be wound to the winding needle 200 when rolling up to the winding needle 200.

[0115] Specifically, in the embodiment of the present application, the first electrode sheet 20 can be a positive electrode sheet or a negative electrode sheet, and the corresponding second electrode sheet 40 can be a negative electrode sheet or a positive electrode sheet, and after the positive electrode sheet is compounded with the positive electrode membrane, the positive electrode membrane is rolled up, and the positive electrode sheet is pulled to achieve rolling up, without the need to perform the positive electrode sheet inserting and feeding action, and after the negative electrode sheet is compounded with the negative electrode membrane, the negative electrode membrane is rolled up, and the negative electrode sheet is pulled to achieve rolling up, without the need to perform the negative electrode sheet inserting and feeding action.

[0116] In this way, by connecting the second diaphragm 30 to one end of the length of the second pole piece 40, the second pole piece 40 can be pulled and wound onto the winding needle 200 during the process of winding the second diaphragm 30 onto the winding needle 200, so as to improve the winding efficiency and further improve the production efficiency of the electrode assembly 100 and the battery cell 300.

[0117] Of course, the structure of the embodiments of the present application is not limited to this. In other embodiments, after the first diaphragm 10 is compounded with the first pole piece 20 and the second diaphragm 30 is compounded with the second pole piece 40, the protruding ends of the first diaphragm 10 and the second diaphragm 30 can be compounded, or the second diaphragm 30 and the first pole piece 20 can be compounded, so that the first diaphragm 10 can sequentially pull the first pole piece 20, the second diaphragm 30, and the second pole piece 40 to achieve winding.

[0118] In other words, the second diaphragm 30 is connected to the same end of the first pole piece 20 in the second direction, or the second diaphragm 30 is connected to the same end of the first diaphragm 10 in the second direction, so that when the first diaphragm 10 is rolled up to the winding needle, the first pole piece 20, the second diaphragm 30 and the second pole piece 40 are driven to be wound to the winding needle in sequence.

[0119] Specifically, the first diaphragm 10, the first pole piece 20, the second diaphragm 30 and the second pole piece 40 are arranged in sequence along the first direction, the first diaphragm 10 is connected to one length end of the first pole piece 20, the second diaphragm 30 is connected to one length end of the first pole piece 20, and the first diaphragm 10 and the second diaphragm 30 are located on both sides of the first pole piece 20 in the first direction, and the second diaphragm 30 is connected to the second pole piece 40 on the other side in the first direction.

[0120] At the same time, the present application can bond the first diaphragm 10 to the first electrode piece 20, the first electrode piece 20 between the first diaphragm 10 and the second diaphragm 30, and bond the first diaphragm 10 and the second diaphragm 30 at the same time, and bond the second electrode piece 40 to the second diaphragm 30, so that the first electrode piece 20, the second electrode piece 40, the first diaphragm 10 and the second diaphragm 30 can be formed into a composite part, and during the winding process of the winding needle 200, the first diaphragm 10 is preferentially wound on the winding needle 200, and synchronously drives the first electrode piece 20 connected to the first diaphragm 10, the second diaphragm 30 connected to the first electrode piece 20, and the second electrode piece 40 connected to the second diaphragm 30 to be wound to the winding needle 200 successively or synchronously.

[0121] Alternatively, the present application can bond the first diaphragm 10 to the first pole piece 20, and the second pole piece 40 to the second diaphragm 30, and the first diaphragm 10 and the second diaphragm 30 protrude from the first pole piece 20 and the second pole piece 40 respectively in the length direction, and the protruding parts are bonded, so that the first pole piece 20, the second pole piece 40, the first diaphragm 10 and the second diaphragm 30 can be formed into a composite part, and during the winding process of the winding needle 200, the first diaphragm 10 is preferentially wound on the winding needle 200, and synchronously drives the second diaphragm 20 and the first pole piece 20, and the second diaphragm 20 further pulls the second pole piece 40, so as to be wound to the winding needle 200 successively or synchronously.

[0122] It is understandable that the above bonding can be achieved directly by providing a glue coating layer, or by other physical means to achieve the connection between the electrode and the diaphragm without changing the physical and chemical properties of the electrode and the diaphragm.

[0123] Of course, the embodiments of the present application are not limited to this. In other embodiments, the first pole piece 20 is connected to the first diaphragm 10, and the second diaphragm 30 is connected to the second pole piece 40, and the first diaphragm 10 and the second diaphragm 30 can be wound on the winding needle 200 synchronously or successively, and the first pole piece 20 and the second pole piece 40 are pulled to be wound on the winding needle 200 respectively.

[0124] That is to say, when the diaphragm and the electrode sheet are wound by the winding needle 200, the first diaphragm 10 is wound up first, and during the rolling process of the first diaphragm 10, the first electrode sheet 20 and the second diaphragm 30 can be driven synchronously, and the second diaphragm 30 pulls the second electrode sheet 40 to be wound onto the winding needle 200. During the winding process of the electrode assembly 100, the feeding action of the first electrode sheet 20, the feeding action of the second electrode sheet 40 and the feeding action of the second diaphragm 30 can be omitted, thereby improving the winding efficiency, thereby improving the processing efficiency of the electrode assembly 100.

[0125] like Figure 6 As shown, there is a first connection area a between the first diaphragm 10 and the first pole piece 20. In the second direction, there is a first interval b between the first connection area a and the adjacent end of the first pole piece 20. The size of the first interval b is 5 mm to 10 mm.

[0126] Specifically, the area connected between the first diaphragm 10 and the first electrode piece 20 is defined as the first connection area a, and the first connection area a is spaced apart from the end of the first electrode piece 20. On the one hand, the gap between the end area of ​​the first electrode piece 20 and the first diaphragm 10, the second diaphragm 30 and the second electrode piece 40 after winding can be made smaller, thereby avoiding the thickness of the end area of ​​the first electrode piece 20 becoming larger due to the setting of the glue layer, so as to reduce the probability of diaphragm breakage in the end area of ​​the first electrode piece 20 after the electrode assembly 100 is in a blanking state; on the other hand, there are burrs in the end area of ​​the first electrode piece 20, and the first electrode piece 20 is connected to the first diaphragm 10 in this area. The burrs may pierce the first diaphragm 10, resulting in a short circuit between the first electrode piece 20 and the second electrode piece 40. Therefore, a first interval b is set between the first connection area a and the end of the first electrode piece 20, which can reduce the probability of short circuit in the electrode assembly 100 and further improve the safety and reliability of the electrode assembly 100.

[0127] It should be pointed out that the first pole piece 20 has two ends in the second direction, one end is arranged adjacent to the first connection area a, and the other end is arranged relatively far away from the first connection area a, and the first interval b between the first pole piece 20 and the first connection area a refers to the distance between one end adjacent to the first connection area a and the first connection area a.

[0128] In addition, it can be understood that the size of the first interval b can be 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, and the first interval b is not less than 5mm and not more than 10mm, so that the distance between the first connection area a and the end of the first electrode plate 20 is more reasonable, thereby improving the reliability and safety of the electrode assembly 100. At the same time, the size of the air avoidance area (ie, the first interval b) is smaller, which can also reduce the cost of the electrode assembly 100.

[0129] Therefore, on the one hand, the first diaphragm 10, the first electrode piece 20, the second diaphragm 30 and the second electrode piece 40 are compositely connected, and the first diaphragm 10 is preferentially rolled into the winding needle 200, so that the first diaphragm 10, the first electrode piece 20, the second diaphragm 30 and the second electrode piece 40 can be synchronously rolled up, eliminating the insertion and feeding action to improve the processing efficiency of the electrode assembly 100. On the other hand, the first connection area a is spaced apart from the end of the first electrode piece 20, which can reduce the probability of the first diaphragm 10 breaking and reduce the probability of the electrode assembly 100 short-circuiting, so as to improve the safety and reliability of the electrode assembly 100.

[0130] According to some embodiments of the present application, the length dimension of the first connection area a is 30 mm to 100 mm.

[0131] Exemplarily, the length dimension of the first connection area a is 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm or 100 mm.

[0132] It can be understood that the length of the first connection area a is not less than 30 mm, which can make the connection stability and reliability between the first pole piece 20 and the first diaphragm 10 higher, and the length of the first connection area a does not exceed 100 mm. While taking into account the connection stability and reliability of the first pole piece 20 and the first diaphragm 10, it can prevent the length of the first connection area a from being too long, thereby reducing the difficulty of connecting the first pole piece 20 and the first diaphragm 10 and further improving the processing efficiency of the electrode assembly 100.

[0133] like Figure 6 As shown, according to some embodiments of the present application, there is a second connection area c between the second pole piece 40 and the second diaphragm 30, and in the second direction, there is a second interval d between the second connection area c and the end of the first pole piece 20, and the size of the second interval d is 5mm~10mm.

[0134] Specifically, the area connected between the second diaphragm 30 and the second electrode piece 40 is defined as the second connection area c, and the second connection area c is spaced apart from the end of the first electrode piece 20. On the one hand, the gap between the end area of ​​the first electrode piece 20 and the second diaphragm 30, the second diaphragm 30 and the second electrode piece 40 after winding can be made smaller, so as to avoid the thickness of the end area of ​​the first electrode piece 20 becoming larger due to the setting of the glue layer, so as to reduce the gap in the end area of ​​the first electrode piece 20 after the electrode assembly 100 is in the blanking state, thereby reducing the probability of diaphragm breakage; on the other hand, there are burrs in the end area of ​​the first electrode piece 20, and the second electrode piece 40 is connected to the second diaphragm 30 in this area. The burrs may pierce the second diaphragm 30, resulting in a short circuit between the first electrode piece 20 and the second electrode piece 40. Therefore, a second interval d is set between the second connection area c and the end of the first electrode piece 20, which can reduce the probability of short circuit in the electrode assembly 100 and further improve the safety and reliability of the electrode assembly 100.

[0135] It should be pointed out that the second pole piece 40 has two ends in the second direction, one end is arranged adjacent to the second connection area c, and the other end is arranged relatively far away from the second connection area c, and the first interval d between the second pole piece 40 and the second connection area c refers to the distance between one end of the second pole piece 40 adjacent to the first connection area c and the first connection area c.

[0136] In addition, it can be understood that the size of the second interval d can be 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, and the first interval b is not less than 5mm and not more than 10mm, so that the distance between the second connection area c and the end of the first electrode sheet 20 is more reasonable, thereby improving the reliability and safety of the electrode assembly 100. At the same time, the size of the air avoidance area (ie, the second interval d) is smaller, which can also reduce the cost of the electrode assembly 100.

[0137] According to some embodiments of the present application, the first connection region a at least partially overlaps with the second connection region c.

[0138] That is, the ends of the first connection region a and the second connection region c may be flush or spaced apart, so that the first connection region a and the second connection region c overlap, or the first connection region a partially overlaps with the second connection region c.

[0139] Thus, in the embodiment where the first connection area a overlaps with the second connection area c, the size of the air avoidance area is smaller in the winding direction of the electrode assembly 100, so that the gap consistency of the electrode assembly 100 after being in the blanking state is better, and in the embodiment where the first connection area a at least partially overlaps with the second connection area c, the bonding accuracy requirements for the first connection area a and the second connection area c are lower, the processing difficulty is lower, and the processing efficiency is higher.

[0140] According to some embodiments of the present application, the length dimension of the second connection area c is 30 mm to 100 mm.

[0141] Exemplarily, the length dimension of the second connection region c is 30 mm, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm or 100 mm.

[0142] It can be understood that the length of the second connection area c is not less than 30 mm, which can make the connection stability and reliability between the second pole piece 40 and the second diaphragm 30 higher, and the length of the second connection area c does not exceed 100 mm. While taking into account the connection stability and reliability of the second pole piece 40 and the second diaphragm 30, it can prevent the length of the second connection area c from being too long, thereby reducing the difficulty of connecting the second pole piece 40 and the second diaphragm 30 and further improving the processing efficiency of the electrode assembly 100.

[0143] According to some embodiments of the present application, the first diaphragm 10 and the first pole piece 20 , the first pole piece 20 and the second diaphragm 30 , and the second diaphragm 30 and the second pole piece 40 are at least partially bonded.

[0144] That is to say, in some embodiments, the first diaphragm 10 and the first electrode piece 20, the first electrode piece 20 and the second diaphragm 30, and the second diaphragm 30 and the second electrode piece 40 are all bonded except for the end avoidance areas (i.e., the first gap b and the second gap d); in other embodiments, only a portion of the first electrode piece 20 is connected to the first diaphragm 10, only a portion of the first electrode piece 20 is connected to the second diaphragm 30, and only a portion of the second diaphragm 30 is connected to the second electrode piece 40.

[0145] It can be understood that in the embodiment where the first diaphragm 10 and the first electrode piece 20, the first electrode piece 20 and the second diaphragm 30, and the second diaphragm 30 and the second electrode piece 40 are all bonded together, the connection strength between the first diaphragm 10 and the first electrode piece 20, the first electrode piece 20 and the second diaphragm 30, and the second diaphragm 30 and the second electrode piece 40 is higher. In the embodiment where the first diaphragm 10 and the first electrode piece 20, the first electrode piece 20 and the second diaphragm 30, and the second diaphragm 30 and the second electrode piece 40 are at least partially bonded together, the processing difficulty of the electrode assembly 100 is lower and the processing efficiency is higher.

[0146] It should be noted that see Figure 4 , Figure 5 and Figure 6 As shown, in the first embodiment of the present application, the first pole piece 20 and the second pole piece 40 are stacked in the first direction and further wound, so that the electrode assembly 100 is constructed as a wound electrode assembly, and in the second embodiment of the present application, see Figure 7 and Figure 8As shown, the second pole piece 40 may be composed of a plurality of sub-pole pieces 41 , and at least a portion of the sub-pole pieces 41 may be formed into a laminate structure after being wound.

[0147] See also Fig. 9 and Fig.10 As shown, according to some embodiments of the present application, the second pole piece 40 includes a plurality of sub-pole pieces 41, and the plurality of sub-pole pieces 41 are arranged sequentially in the second direction before winding, and after the electrode assembly 100 is wound, the projected contours in the direction of the winding axis, some of the sub-pole pieces 41 are formed into arc contours, and some of the sub-pole pieces 41 are formed into annular contours.

[0148] It should be noted that after the plurality of sub-pole sheets 41 are sequentially arranged along the length direction, they are wound by the winding needle 200, and after the winding is completed, at least part of the sub-pole sheets 41 is formed into Fig. 9 As shown in the projection profile, another part of the sub-pole piece 41 is formed as Fig.10 The projected contour shown is so that a winding structure is formed between part of the sub-pole piece 41 and the first pole piece 20, while a stacked structure is formed between another part of the sub-pole piece 41 and the first pole piece 20. The number of sub-pole pieces 41 forming a stacked structure is 3 to 8 pieces, such as 3, 4, 5, 6, 7 or 8 pieces, and the sub-pole piece 41 forming a winding structure can also be connected to the second diaphragm 30, which can omit the insertion and feeding action, and realize the stacked structure processing through winding.

[0149] Thus, the winding efficiency and the lamination efficiency can be improved, thereby improving the processing efficiency of the electrode assembly 100 .

[0150] like Figure 8 As shown, the sub-pole piece 41 defining an annular contour is connected to the first diaphragm 10 and the second diaphragm 30. After the winding is completed, the sub-pole piece 41 defining an arc contour is located radially inside and / or radially outside the sub-pole piece 41 defining an annular contour, and the sub-pole piece 41 with an annular contour is connected to the first diaphragm 10 and the second diaphragm 30.

[0151] As a result, at least a portion of the second pole piece 40 can be constructed as a stacked structure, which is beneficial to improving the consistency of the interlayer gap in the corner area (hereinafter referred to as the bending area f) of the electrode assembly 100 in the blanking state, and can reduce the probability of cracking of the outer ring pole piece, thereby improving the safety and reliability of the electrode assembly 100.

[0152] According to some embodiments of the present application, the length of the sub-pole sheet 41 defining an arc-shaped profile gradually increases in a direction away from the winding axis of the electrode assembly 100 .

[0153] It can be understood that as the winding needle 200 is wound, the outer diameter of the electrode assembly 100 wound on the winding needle 200 gradually increases, so that the length of the sub-pole piece 41 with the arc-shaped contour relatively located on the radial outside is greater than the length of the sub-pole piece 41 with the arc-shaped contour relatively located on the radial inside, so that the effective area of ​​the electrode assembly 100 after processing is larger (the area where the first pole piece 20 and the second pole piece 40 are opposite to each other on both sides of a second diaphragm 30 is defined as the effective area, and the area where only the first pole piece 20 or the second pole piece 40 is only provided in a certain area is defined as the invalid area), and the energy density of the electrode assembly 100 is higher.

[0154] See also Figure 8 As shown, according to some embodiments of the present application, after the electrode assembly 100 is cut, the electrode assembly 100 defines a main body area e and bending areas f located on both sides of the main body area e, and at least one end of the sub-pole piece 41 with an arc-shaped contour is located in the main body area e.

[0155] It should be pointed out that after the electrode assembly 100 is cut, it will be further extruded in the radial direction and deformed into the oblong or runway-shaped outline as shown in the figure, and the two ends of the electrode assembly 100 are formed into bending areas f, and the middle area corresponds to the area where the large surface of the battery cell 300 of the battery cell 300 is located, forming the main area e, so that at least one end of the sub-pole piece 41 with an arc-shaped outline in the wound state, the projected outline in the cut-out state is located within the straight line edge defined by the main area e, that is, located in the area where the large surface of the battery cell 300 is located, which can improve the interlayer gap in the bending area f at one end of the electrode assembly 100, improve the consistency of the interlayer gap in the bending area f, and reduce the stress concentration problem in the bending area f, so as to reduce the probability of cracking of the outer ring electrode piece and improve the reliability and stability of the electrode assembly 100.

[0156] like Figure 3 As shown, the present application proposes a battery cell 300 , including: the electrode assembly 100 in the above embodiment.

[0157] like Figure 2 As shown, an embodiment of the present application provides a battery device 400, including: the battery cell 300 in the above embodiment, the battery cell 300 is used to store or provide electrical energy.

[0158] The present application proposes a manufacturing device for a battery cell 300, the manufacturing device includes a winding needle 200, the winding needle 200 is used to wind the electrode assembly 100 of the above-mentioned battery cell 300, and the winding needle 200 is constructed as a vacuum adsorption winding needle, the end of the first diaphragm 10 protrudes from the first pole piece 20 in the second direction, and the protruding length C1 and the outer circumferential length C2 of the winding needle 200 satisfy: 0.25C2≤C1≤0.75C2.

[0159] Here, it should be pointed out that see Fig.11 and Fig.12 As shown, the clamping winding needle used in the prior art is defined as 200', the electrode assembly in the prior art is 100', the first diaphragm is 10', the first pole piece is 20', the second diaphragm is 30', and the second pole piece is 40'. In the prior art, the first diaphragm 10' and the first pole piece 20', the second diaphragm 30' and the second pole piece 40', and the first pole piece 20' and the second diaphragm 30' are all independently arranged, and there is no connection relationship and constraint between them. In the process of winding, they need to be clamped and fixed by the clamping winding needle 200'. The first diaphragm 10' and the second diaphragm 30' result in that the end area lengths of the first diaphragm 10' and the second diaphragm 30' need to be set larger. The circumference of the winding needle 200 is defined as C, and the end area length (i.e., the head end of the diaphragm used for winding and clamping on the winding needle 200) needs to be at least 1.25C (for example, if the circumference of the winding needle 200 is 10mm, the end area length needs to be 12.5mm). The amount of diaphragm used is large, the material cost is high, and it is difficult to fix the diaphragm on the winding needle 200, resulting in low production efficiency.

[0160] In other words, see Fig.11 As shown, in the prior art, when the electrode assembly 100' is in a blanking state, the innermost side of the electrode assembly 100' is the end region of the diaphragm (i.e., the clamping and rolling region of the diaphragm), the projection profile of the end region of the diaphragm is S-shaped, the length of the end region is large, and the material cost is high.

[0161] Based on this, according to some embodiments of the present application, the electrode assembly 100 is circumferentially wound on the winding needle 200, the winding needle 200 is constructed as a vacuum adsorption winding needle 200, at least one end of the first diaphragm 10 and the second diaphragm 30 is protruding, and the protruding length C1 and the outer circumferential length C2 of the winding needle 200 satisfy: 0.25C2≤C1≤0.75C2.

[0162] Specifically, combined Fig.11 and Fig.12 As shown, it can be concluded that the end regions of the first diaphragm 10 and the second diaphragm 30 in the lower state in the prior art are both S-shaped, and the Figure 4 , Figure 5 or Figure 7 and Figure 8 As shown, in the embodiment of the present application, the end regions of the first diaphragm 10 and the second diaphragm 30 are C-shaped.

[0163] That is to say, the manufacturing equipment of the embodiment of the present application cooperates with the above-mentioned electrode assembly 100 through a vacuum adsorption winding needle. While the first diaphragm 10, the second diaphragm 30, the first pole piece 20 and the second pole piece 40 are compositely connected, a vacuum adsorption winding needle 200 is used. There is no need to reserve a portion for clamping the winding needle 200. The length of the end area of ​​the first diaphragm 10 and the second diaphragm 30 can be shorter, and the corresponding protrusion length (that is, the end area length) can be 0.25C2~0.75C2. For example: if the circumference of the winding needle 200 is 10mm, the protrusion length can be controlled within 2.5mm~7.5mm.

[0164] It can be understood that a protrusion length of not less than 0.25C2 can increase the adsorption strength between the diaphragm and the winding needle 200 to improve the winding effect, while a protrusion length of not more than 0.75C2 can effectively reduce the protrusion length, making the length of the end blank diaphragm shorter, lower material cost and higher production efficiency.

[0165] like Fig.13 As shown, an embodiment of the present application provides an energy storage system 900, including: a power conversion device 920 and the battery device 400 in the above embodiment, and the power conversion device 920 is used to electrically connect the power generation device 910 and the energy storage device.

[0166] like Figure 1 As shown, an embodiment of the present application provides an electric device 500, including: a battery cell 300 in the above embodiment, or an energy storage system 900, the battery cell 300 or the energy storage system is used to store or provide electric energy.

[0167] Other structures and operations of the battery cell 300 , the battery device 400 , the energy storage system 900 and the power consumption device 500 according to the embodiment of the present invention are known to those skilled in the art and will not be described in detail here.

[0168] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0169] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that: include: case; An electrode assembly, the electrode assembly being arranged in the housing, the electrode assembly comprising: a first diaphragm (10), a first pole piece (20), a second diaphragm (30) and a second pole piece (40) stacked in a first direction, The first diaphragm (10) and the second diaphragm (30) are located on both sides of the first pole piece (20) in the first direction, and the first diaphragm (10) and the first pole piece (20) are connected at the same end in the second direction, and the end of one end of the first diaphragm (10) connected to the first pole piece (20) protrudes from the first pole piece (20) in the second direction, the second diaphragm (30) and the second pole piece (40) are connected at the same end in the second direction, and the end of one end of the second diaphragm (30) and the second pole piece (40) are connected to the second pole piece (40) in the second direction, and the second diaphragm (30) and the first pole piece (20) are connected at the same end in the second direction, so that when the first diaphragm (10) is rolled up to the winding needle, the first pole piece (20), the second diaphragm (30) and the second pole piece (40) are driven to be wound to the winding needle in sequence, and the first direction is orthogonal to the second direction.

2. The battery cell according to claim 1, characterized in that: The connecting area of ​​the first diaphragm (10) and the first pole piece (20) at the same end in the second direction is a first connecting area (a), and in the second direction, there is a first gap (b) between the first connecting area (a) and the adjacent end of the first pole piece (20), and the size of the first gap (b) is 5 mm to 10 mm.

3. The battery cell according to claim 2, characterized in that: The length of the first connection area (a) is 30 mm to 100 mm.

4. The battery cell according to claim 1, characterized in that: The connecting area of ​​the second pole piece (40) and the second diaphragm (30) at the same end in the second direction is a second connecting area (c), and in the second direction, there is a second interval (d) between the second connecting area (c) and the adjacent end of the first pole piece (20), and the size of the second interval (d) is 5 mm to 10 mm.

5. The battery cell according to claim 4, characterized in that: The first connection area (a) at least partially overlaps with the second connection area (c).

6. The battery cell according to claim 4, characterized in that: The length of the second connection area (c) is 30 mm to 100 mm.

7. The battery cell according to claim 1, characterized in that: The second pole piece (40) comprises a plurality of sub-pole pieces, the plurality of sub-pole pieces being arranged in sequence in the second direction, and after the electrode assembly is wound, the projected contours in the direction of the winding axis are such that some of the sub-pole pieces (41) are formed into arc contours, and some of the sub-pole pieces (41) are formed into annular contours.

8. The battery cell according to claim 7, characterized in that: The sub-pole piece (41) defining the annular contour is connected to the first diaphragm (10) and the second diaphragm (30).

9. The battery cell according to claim 7, characterized in that: The sub-pole sheet (41) defining the arc-shaped contour gradually increases in length in a direction away from the winding axis of the electrode assembly.

10. The battery cell according to any one of claims 7 to 9, characterized in that: After the electrode assembly is cut, the electrode assembly defines a main body area (e) and bending areas (f) located on both sides of the main body area (e), and defines that at least one end of the sub-electrode sheet (41) with the arc-shaped profile is located in the main body area (e).

11. A battery device, characterized in that: include: The battery cell according to any one of claims 1 to 10, wherein the battery cell is used to store or provide electrical energy.

12. A battery cell manufacturing device, characterized in that: include: A winding needle, the winding needle is used for winding the electrode assembly of the battery cell according to any one of claims 1 to 10, and the winding needle is constructed as a vacuum adsorption winding needle, the end of the first diaphragm (10) protrudes from the first pole piece (20) in the second direction, and the protruding length C1 and the outer circumferential length C2 of the winding needle satisfy: 0.25C2≤C1≤0.75C2.

13. An energy storage system, characterized in that: include: A power conversion device and a battery device as claimed in claim 11, wherein the power conversion device is used to electrically connect a power generation device and a battery device.

14. An electrical device, characterized in that: include: The battery device according to claim 11, or the energy storage system according to claim 13, wherein the battery device or the energy storage system is used to store or provide electrical energy.

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