Battery monomer, battery device and electric equipment

Abstract

The utility model discloses a battery monomer, a battery device and electric equipment. The battery monomer comprises a shell and an electrode assembly, wherein the electrode assembly comprises a first pole piece, a second pole piece and a first insulating part; the first pole piece comprises a first current collector and a first film layer, the first current collector comprises a first current collector main body and a first tab, and the first tab is led out from the end part of the first current collector main body along the first direction; the first film layer is arranged on the first surface of the first collector body and comprises a body area and a thinning area, and the thickness of the body area is larger than that of the thinning area. The first insulating part comprises a first insulating part and a second insulating part, the first insulating part is arranged on the side, away from the first current collector, of the thinning area and points to the direction of the thinning area along the main body area, the end, away from the first insulating part, of the second insulating part exceeds the end face of the first current collector main body, and the thickness of the first insulating part is smaller than that of the second insulating part. In the thickness direction, the first insulating part does not exceed the second surface, away from the first collector body, of the body region.

Description

Technical Field

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

[0002] With the development of new energy technologies, batteries are becoming increasingly widely used. For example, batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace, among other fields.

[0003] The development of battery technology must take into account multiple design factors at the same time, such as energy density, cycle life, assembly efficiency, processing technology, etc., and battery reliability must also be considered. Utility Model Content

[0004] The embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can reduce the risk of conduction between the positive and negative electrodes and improve the reliability of the battery cell.

[0005] According to a first aspect of the present application, a battery cell is provided, comprising a housing and an electrode assembly housed within the housing, the electrode assembly comprising a first electrode piece and a second electrode piece of opposite polarity. The first electrode piece comprises a first current collector and a first film layer, the first current collector comprises a first current collector body and a first electrode tab, the first electrode tab extending from an end portion of the first current collector body along a first direction, the first direction being perpendicular to the thickness direction of the first current collector, the first film layer being disposed on a first surface of the first current collector body along the thickness direction, the first film layer comprising a main body region and a thinning region, the thinning region being connected to the main body region and located on a side of the main body region facing the first electrode tab, the main body region having a thickness greater than that of the thinning region. The electrode assembly also includes a first insulating member, which is connected to the first pole piece and includes a first insulating portion and a second insulating portion arranged along a first direction. The first insulating portion is arranged on the side of the thinning area away from the first current collector, and along the direction of the main area pointing to the thinning area, the end of the second insulating portion away from the first insulating portion exceeds the end surface of the first current collector facing the first pole ear, and the thickness of the first insulating portion is less than the thickness of the second insulating portion; along the thickness direction of the first current collector, the first insulating member does not exceed the second surface of the main area away from the first current collector.

[0006] By providing a thinning region, the embodiments of the present application can reduce the possibility of bulging at the die-cut edge after winding or stacking the first electrode sheet. Furthermore, the first insulating portion, which is thinner in thickness, is located on the side of the thinning region facing away from the first current collector. The thinning space in the thinning region can be used to accommodate the first insulating portion, saving space. The second insulating portion, which is relatively thicker, extends beyond the end face of the first current collector, reducing the possibility of the second insulating portion being punctured by burrs or metal particles on the end face, thereby reducing the risk of conduction between the positive and negative electrodes and improving the reliability of the battery cell.

[0007] In some embodiments, the second insulating portion is located on the side of the thinned region facing away from the main body region. The relatively thick second insulating portion and the thinned region do not overlap in thickness. Within the range of not exceeding the second surface of the main body region, the thickness of the second insulating portion can be appropriately increased to improve its structural strength, further reduce the possibility of the second insulating portion being punctured by burrs or metal particles, and further improve the reliability of the battery cell.

[0008] In some embodiments, the electrode assembly further includes a second insulating member. The second insulating member and the first insulating member are respectively disposed on either side of the first electrode sheet along the thickness direction of the first current collector. A portion of the second insulating member is located on one side of the first current collector body along the thickness direction of the first current collector, extending beyond the end surface along the direction from the first current collector body toward the first electrode tab. The second insulating member is connected to the second insulating portion. The second insulating portion and the second insulating member can respectively shield burrs, metal particles, and the like on the end surface from both sides of the end surface along the thickness direction of the first current collector, thereby further reducing the risk of positive and negative electrode conduction and improving the reliability of the battery cell.

[0009] In some embodiments, the second insulating portion includes a second insulating film layer and a second adhesive layer. The second adhesive layer is disposed on the side of the second insulating film layer facing the first pole piece, and at least a portion of the second adhesive layer is bonded to the second insulating member. The second insulating portion is bonded to the second insulating member via the second adhesive layer, which improves the connection stability between the first and second insulating members and simplifies the assembly process. The second insulating film layer has relatively high structural strength and is not easily punctured.

[0010] In some embodiments, the first insulating portion includes a first insulating film layer, which is attached to a third surface of the thinned region facing away from the first current collector. There is no adhesive bond between the first insulating film layer and the third surface, and a certain gap can be formed between the first insulating film layer and the third surface, which facilitates filling with electrolyte and allowing the electrolyte to contact the thinned region. The structural design of the first insulating portion without an adhesive layer can reduce the first insulating portion's coverage of the active material in the thinned region, thereby facilitating the utilization of the capacity of the portion of the thinned region covered by the first insulating portion and reducing the impact on the capacity of the first electrode.

[0011] In some embodiments, the first insulating part includes a first insulating film layer and a first adhesive layer, the first adhesive layer is arranged on a side of the first insulating film layer facing the first tab, and is bonded to the thinning area; the thickness of the first adhesive layer is less than the thickness of the second adhesive layer. The thickness of the first adhesive layer is relatively small, which can reduce the possibility of overflow of the first adhesive layer towards the main body area, thereby reducing the shielding degree of the active substance of the first film layer by the first adhesive layer and reducing the capacity impact on the first tab. The thickness of the second adhesive layer is relatively large, which can increase the connection strength between the second insulating part and the second insulating member or the first tab, improve the structural strength of the second insulating part, and further reduce the risk of the second insulating part being pierced by burrs or metal particles.

[0012] In some embodiments, the thickness of the first insulating film layer is less than or equal to the thickness of the second insulating film layer. The thickness of the first insulating film layer is relatively small, which is conducive to reducing the overall thickness and space occupied by the first insulating part. The thickness of the second insulating film layer is relatively large, which is conducive to increasing the structural strength of the second insulating part and further reducing the risk of the second insulating part being pierced by burrs or metal particles.

[0013] In some embodiments, the first current collecting main body has two first surfaces arranged opposite along the thickness direction of the first current collector, the first tab includes two first film layers, and the two first film layers are symmetrically arranged at the two first surfaces; the first insulating member and the second insulating member are symmetrically arranged. Both of the two insulating members do not increase the thickness of the edge of the first tab, thereby reducing the possibility of edge bulging of the electrode assembly. Both of the two insulating members are provided with an insulating part (the second insulating part and the fourth insulating part) with a relatively large thickness, and are not easily pierced by burrs or metal particles, which is conducive to reducing the risk of the first tab being conductive with the second tab located on both sides of the first tab and improving the reliability of the battery cell.

[0014] In some embodiments, along the thickness direction of the first current collector, one end of the thinning area away from the main body area is flush with one end of the first current collecting main body facing the first tab; and the second insulating part is arranged on the outer side of the first current collecting main body facing the first tab. In this way, the area of the first film layer can be as large as possible, the coverage area of the active substance can be increased, and the capacity of the first tab can be improved.

[0015] In some embodiments, the end face includes a tab leading-out area and a non-tab leading-out area, the first tab extends out only from the tab leading-out area and protrudes from the second insulating part in a direction away from the first current collecting main body; and the second insulating part is arranged only on the outer side of the non-tab leading-out area in the first direction. Along the thickness direction of the first current collector, the second insulating part does not cover the first tab, which can increase the length of the first tab that can be connected with the conductive structure and further reduce the risk of interference between the second insulating part and the conductive structure.

[0016] In some embodiments, the first surface includes a coated region and an uncoated region arranged along a first direction, one end of the uncoated region being connected to the end face and the other end being connected to the coated region, the coated region being coated with the first film layer, and the uncoated region being uncoated with the first film layer; along the thickness direction of the first current collector, the second insulating portion covers the uncoated region. By providing the uncoated region on the first surface, embodiments of the present application can increase the contact area between the first current collector and the first insulating member, reduce the risk of the first insulating member falling off, and improve its stability and reliability. The end face and the first film layer are spaced apart along the first direction, which can reduce the risk of cutting the first film layer during cutting of the first electrode sheet and reduce waste of active material.

[0017] In some embodiments, the second insulating portion includes a second insulating film layer and a second adhesive layer. The second adhesive layer is disposed on a side of the second insulating film layer facing the first pole piece, and at least a portion of the second adhesive layer is bonded to the uncoated area. The second insulating portion is bonded to the uncoated area via the second adhesive layer, thereby improving the connection strength and stability between the first insulating member and the first pole piece and reducing the possibility of the first insulating member falling off.

[0018] In some embodiments, the end surface includes a tab lead-out region and a non-tab lead-out region. The first tab extends only from the tab lead-out region and protrudes beyond the second insulating portion in a direction away from the first current collector. The second insulating portion includes a first extension and a second extension. The first extension is located outside the non-tab lead-out region in the first direction, while the second extension is located outside the tab lead-out region in the first direction and covers a portion of the first tab along the thickness direction of the first current collector. Along the thickness direction of the first current collector, the first extension may cover the non-tab lead-out region to shield burrs or metal particles on the non-tab lead-out region. Along the thickness direction of the first current collector, the second extension may cover the root of the second tab near the first current collector, shielding burrs at the root of the first tab and reducing the risk of cracking at the root of the first tab. This also reduces the risk of the first tab being inserted upside down between the first and second pole pieces when bent.

[0019] In some embodiments, the first insulating portion is spaced apart from the main region along the first direction. Along the thickness direction of the first current collector, the first insulating portion only covers a portion of the thinned region, which facilitates more active material in the first film layer to contact the electrolyte and reduces capacity loss in the battery cell.

[0020] In some embodiments, the thickness of the second insulating portion is less than the thickness of the main region; and / or the thickness of the first insulating portion is less than the maximum thickness difference between the main region and the thinning region, which helps to reduce the possibility of bulging of the die-cut edge of the electrode assembly.

[0021] According to a second aspect of the present application, an embodiment of the present application provides a battery device, which includes a plurality of battery cells provided according to any embodiment of the present application.

[0022] According to a third aspect of the present application, an embodiment of the present application provides an electrical device, which includes a battery device provided according to any embodiment of the present application, and the battery device is used to provide electrical energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0024] Figure 1 It is a schematic structural diagram of a vehicle provided in some embodiments of the present application.

[0025] Figure 2 It is a schematic diagram of the exploded structure of the battery device provided in some embodiments of the present application.

[0026] Figure 3 This is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application.

[0027] Figure 4 Schematic top view of an electrode assembly of a battery cell provided in some embodiments of the present application.

[0028] Figure 5 for Figure 4 Schematic diagram of a local section taken along the AA direction.

[0029] Figure 6 This is a schematic structural diagram of the first pole piece of a battery cell in a flattened state provided in some embodiments of the present application.

[0030] Figure 7 yes Figure 6 Schematic diagram of the cross-sectional structure along the BB direction.

[0031] Figure 8 yes Figure 6 The diagram shows a structural diagram of the first pole piece, the first insulating member and the second insulating member after being connected.

[0032] Figure 9 yes Figure 8 Schematic diagram of the cross-sectional structure along the CC direction.

[0033] Figure 10 yes Figure 8 Schematic diagram of the cross-sectional structure along the DD direction.

[0034] Figure 11 This is a schematic cross-sectional structural diagram of a battery cell after the first pole piece, the first insulating member, and the second insulating member are connected, provided in other embodiments of the present application.

[0035] Figure 12 yes Figure 11 Schematic diagram of the cross-sectional structure along the EE direction.

[0036] Figure 13 This is a partial cross-sectional structural diagram of a battery cell after the first pole piece, the first insulating member, and the second insulating member are connected, provided in some embodiments of the present application.

[0037] In the attached figure:

[0038] Tag Name

[0039] Vehicle 1, battery device 2, controller 3, motor 4, box 5, battery cell 6;

[0040] Electrode assembly 10, first pole piece 11, first current collector 111, first film layer 112, main body area 1121, second surface 1121a, thinning area 1122, third surface 1122a, first current collector body 113, first surface 1131, coated area 1131a, uncoated area 1131b, end surface 1132, tab lead-out area 1132a, non-tab lead-out area 1132b, first tab 114, first insulating film layer 1141, second pole piece 12, second current collector 121, second film layer 122 , isolating member 13, first insulating member 14, first insulating portion 141, first insulating film layer 1411, first adhesive layer 1412, second insulating portion 142, second insulating film layer 1421, second adhesive layer 1422, first extension portion 142a, second extension portion 142b, second insulating member 15, third insulating portion 151, fourth insulating portion 152, outer shell 20, shell 21, end cover 22, first insulating member 23, electrode terminal 30, first box body portion 5a, second box body portion 5b, first direction X, thickness direction Y. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" 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-secondary relationship.

[0043] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0045] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0046] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

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

[0048] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0049] In the embodiment of the present application, the battery cell may be a secondary battery cell. A secondary battery cell refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0050] A battery cell typically includes an electrode assembly, which includes a positive electrode sheet and a negative electrode sheet. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. For example, the electrode assembly also includes a separator disposed between the positive and negative electrode sheets. The separator prevents short circuits between the positive and negative electrode sheets while allowing active ions to pass through.

[0051] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present application are not limited to this.

[0052] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, such as a hexagonal battery, etc. There is no special limitation in this application.

[0053] The battery cells may be hard-shell battery cells, soft-pack battery cells, or other types of battery cells.

[0054] The battery device 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, parallel, or hybrid via a busbar.

[0055] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells. A battery device generally includes a housing for enclosing one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0056] For example, the battery cell assembly can be a battery module, which is composed of multiple battery cells arranged and fixed to form a separate module. For example, the battery module can be formed by bundling multiple battery cells with cable ties. The battery cell assembly can be housed in a box by fixing the battery module in the box.

[0057] As an example, the box may include a top cover, a frame, and a bottom plate, wherein the top cover and the bottom plate are respectively connected to the frame to form a closed space inside the box to accommodate the battery cell assembly.

[0058] 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.

[0059] In some embodiments, the battery device may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0060] A battery cell generally consists of an electrode assembly and a housing, with the electrode assembly housed within the housing. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and released back and forth between the positive and negative electrodes. A separator is placed between the positive and negative electrodes to reduce the risk of short circuits while allowing active ions to pass through.

[0061] The housing is used to encapsulate the electrode assembly and electrolyte components. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film.

[0062] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode film layer disposed on at least one surface of the positive electrode current collector. The negative electrode may be a negative electrode sheet, which may include a negative electrode current collector and a negative electrode film layer disposed on at least one surface of the negative electrode current collector.

[0063] During the preparation of the electrode (positive or negative), it is usually necessary to cut (for example, the electrode slitting process or the tab die-cutting process) to form the required size and shape. However, after cutting, the current collector is prone to burrs or metal particles at the cutting position. During the charge and discharge process of the battery cell, the burrs or metal particles may puncture the separator and connect the positive and negative electrodes, causing a short circuit risk and affecting the reliability of the battery cell.

[0064] To address this issue, one feasible solution is to insulate the cut edges of the electrode sheets with insulating tape. However, the electrode sheets are relatively thin, and covering them with insulating tape increases the thickness of the cut edges, leading to bulging edges in the die-cut electrode assembly.

[0065] In view of this, the embodiments of the present application provide a technical solution. By providing a first insulating member of non-uniform thickness on the electrode sheet, the first insulating portion of the first insulating member with a smaller thickness covers the thinned area of ​​the film layer, thereby reducing the thickness space occupied by the first insulating portion. This is beneficial for the first insulating member to not extend beyond the main area of ​​the film layer and away from the surface of the first current collector, thereby reducing the risk of bulging edges in the die-cutting of the electrode assembly. The second insulating portion of the first insulating member with a larger thickness extends beyond the end face of the current collector, thereby reducing the possibility of the second insulating portion being punctured by burrs or metal particles on the end face of the current collector, reducing the risk of positive and negative electrode conduction, and improving the reliability of the battery cell.

[0066] The technical solutions provided in the embodiments of the present application are applicable to battery cells, battery devices, and electrical equipment using the battery devices.

[0067] The battery device disclosed in the embodiments of the present application can be used in various energy storage systems that use the battery device as a power source or use the battery device as an energy storage element. The power-consuming device can be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery car, an electric car, a ship, a spacecraft, and the like. Among them, the electric toy can 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, and the spacecraft can include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0068] For the convenience of description, the following embodiments are described by taking a vehicle as an example of an electrical device.

[0069] Figure 1 Schematic diagram of the structure of the vehicle provided by some embodiments of the present application. Figure 1 Vehicle 1 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle. A battery device 2 is provided inside vehicle 1. Battery device 2 can be located at the bottom, head, or tail of vehicle 1. Battery device 2 can be used to power vehicle 1. For example, battery device 2 can serve as an operating power source for vehicle 1. Vehicle 1 can also include a controller 3 and a motor 4. Controller 3 is used to control battery device 2 to power motor 4, for example, to meet the power requirements of vehicle 1 during startup, navigation, and driving.

[0070] In some embodiments of the present application, the battery device 2 can serve not only as an operating power source for the vehicle 1 , but also as a driving power source for the vehicle 1 , replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1 .

[0071] Figure 2 Schematic diagram of the exploded structure of the battery device provided in some embodiments of the present application. Figure 2The battery device 2 includes a housing 5 and a battery cell 6, and the battery cell 6 is accommodated in the housing 5. The housing 5 is used to provide a storage space for the battery cell 6, and the housing 5 can adopt a variety of structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b, and the first housing portion 5a and the second housing portion 5b cover each other, and the first housing portion 5a and the second housing portion 5b jointly define a storage space for accommodating the battery cell 6. The second housing portion 5b can be a hollow structure with one end open, and the first housing portion 5a can be a plate-shaped structure, and the first housing portion 5a covers the open side of the second housing portion 5b, so that the first housing portion 5a and the second housing portion 5b jointly define a storage space; the first housing portion 5a and the second housing portion 5b can also be hollow structures with one side open, and the open side of the first housing portion 5a covers the open side of the second housing portion 5b. Of course, the box body 5 formed by the first box body portion 5a and the second box body portion 5b can be in various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0072] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0073] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0074] In the battery device 2, there may be multiple battery cells 6, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections within the battery cells 6. Multiple battery cells 6 may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery unit 6 is housed within the housing 5. Alternatively, the battery device 2 may comprise multiple battery cells 6 that are first connected in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single unit housed within the housing 5. The battery device 2 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 6.

[0075] For example, the battery cell 6 may be the smallest unit constituting the battery device 2 .

[0076] Figure 3 This is a schematic diagram of the exploded structure of a battery cell provided in some embodiments of the present application. Figure 3The battery cell 6 includes a housing 20 and an electrode assembly 10, and the electrode assembly 10 is disposed in the housing 20. The electrode assembly 10 includes a positive electrode and a negative electrode. During the charge and discharge process of the battery cell 6, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. Optionally, the electrode assembly 10 also includes a separator disposed between the positive electrode and the negative electrode. The separator can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0077] The housing 20 is used to encapsulate the electrode assembly 10 and the electrolyte and other components. The housing 20 can be a steel housing, an aluminum housing, a plastic housing (such as polypropylene), a composite metal housing (such as a copper-aluminum composite housing), or an aluminum-plastic film.

[0078] In some embodiments, the housing 20 is a hollow structure, and a space is formed inside the housing to accommodate the electrode assembly 10 and the electrolyte. The shape of the housing 20 can be determined according to the specific shape of the electrode assembly 10. For example, if the electrode assembly 10 is a rectangular parallelepiped structure, a rectangular housing can be used.

[0079] The housing 20 can be made of a variety of materials, for example, metal or plastic. Alternatively, the housing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the housing 20 can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film.

[0080] As an example, the housing 20 includes a shell 21 and an end cover 22 . The shell 21 has an opening, and the end cover 22 is used to cover the opening.

[0081] The housing 21 is a component used to cooperate with the end cover 22 to form an internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly 10, electrolyte and other components.

[0082] The housing 21 and the end cap 22 may be separate components. For example, an opening may be provided on the housing 21 , and the end cap 22 may be placed over the opening to form an internal cavity of the battery cell 6 .

[0083] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from that of the housing 21.

[0084] The end cover 22 can be connected to the housing 21 by welding, bonding, clamping or other methods.

[0085] The housing 21 can be open at one end or at both ends. Exemplarily, the housing 21 is open at one side, and the end cover 22 is arranged as one and covers the opening of the housing 21. As another example, the housing 21 can also be open at both sides, and the end cover 22 is arranged as two, and the two end covers 22 cover the two openings of the housing 21 respectively.

[0086] In some embodiments, the battery cell 6 includes an electrode terminal 30 electrically connected to the electrode assembly 10 for inputting or outputting electric energy of the battery cell 6.

[0087] In some embodiments, referring to Figure 3 , the battery cell 6 includes a housing 20, an electrode assembly 10 arranged in the housing 20, and a first insulating member 23.

[0088] Figure 4 is a top view of an electrode assembly of a battery cell provided by some embodiments of the present application, Figure 5 is Figure 4 is a partial cross-sectional view taken along the A-A direction. Referring to Figure 4 and Figure 5 , the electrode assembly 10 includes a first electrode tab 11 and a second electrode tab 12 with opposite polarities.

[0089] Exemplarily, one of the first electrode tab 11 and the second electrode tab 12 is a positive electrode tab, and the other is a negative electrode tab.

[0090] In some embodiments, the positive electrode tab can include a positive electrode current collector and a positive electrode film layer arranged on at least one surface of the positive electrode current collector. As an example, the positive electrode current collector has two opposite surfaces in the thickness direction of itself, and the positive electrode film layer is arranged on any one or both of the two opposite surfaces of the positive electrode current collector.

[0091] As an example, the positive electrode current collector can adopt carbon, metal foil or composite current collector. The positive electrode film layer includes positive electrode active material, which can include at least one of the following materials: lithium-containing phosphate, lithium transition metal oxide and their respective modified compounds.

[0092] In some embodiments, the negative electrode tab can include a negative electrode current collector and a negative electrode film layer arranged on at least one surface of the negative electrode current collector. As an example, the negative electrode current collector has two opposite surfaces in the thickness direction of itself, and the negative electrode film layer is arranged on any one or both of the two opposite surfaces of the negative electrode current collector.

[0093] As an example, the negative electrode current collector can adopt metal foil, foamed metal or composite current collector. The negative electrode film layer includes negative electrode active material, which can include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based material, tin-based material and lithium titanate, etc.

[0094] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0095] In some embodiments, the electrode assembly 10 further includes a separator 13, which is used to separate the first electrode 11 from the second electrode 12. The separator 13 can reduce the risk of short circuit between the positive and negative electrodes while allowing active ions to pass through.

[0096] In some embodiments, the separator 13 includes an isolation membrane. The isolation membrane of the present application can be any known porous structure isolation membrane with good chemical stability and mechanical stability.

[0097] In some embodiments, the electrode assembly 10 is a wound structure. For example, the first electrode sheet 11 and the second electrode sheet 12 are both strip-shaped structures, and the first electrode sheet 11, the separator 13, and the second electrode sheet 12 are wound into a wound structure.

[0098] In some embodiments, the electrode assembly 10 is a laminated structure. As an example, a plurality of first electrode sheets 11 and a plurality of second electrode sheets 12 may be provided, and the plurality of first electrode sheets 11 and the plurality of second electrode sheets 12 may be alternately stacked.

[0099] Figure 6 is a schematic structural diagram of the first pole piece of a battery cell in a flattened state provided in some embodiments of the present application. Figure 7 yes Figure 6 Schematic diagram of the cross-sectional structure made along the BB direction, Figure 8 yes Figure 6 The schematic diagram of the structure after the first pole piece, the first insulating member and the second insulating member are connected is shown. Figure 9 yes Figure 8 Schematic diagram of the cross-sectional structure made along the CC direction, Figure 10 yes Figure 8 Schematic diagram of the cross-sectional structure made along the DD direction, Figure 11 is a schematic cross-sectional structural diagram of a battery cell after the first pole piece, the first insulating member, and the second insulating member are connected, provided in other embodiments of the present application. Figure 12 yes Figure 11 Schematic diagram of the cross-sectional structure made along the EE direction, Figure 13 This is a partial cross-sectional structural diagram of a battery cell after the first pole piece, the first insulating member, and the second insulating member are connected, provided in some embodiments of the present application.

[0100] Reference Figures 4 to 13 The battery cell 6 provided in the embodiment of the present application includes a housing 20 and an electrode assembly 10 accommodated in the housing 20. The electrode assembly 10 includes a first electrode sheet 11 and a second electrode sheet 12 with opposite polarities.

[0101] The first electrode sheet 11 includes a first current collector 111 and a first film layer 112. The first current collector 111 includes a first current collecting body 113 and a first electrode tab 114. The first electrode tab 114 extends from the end of the first current collecting body 113 along a first direction X, which is perpendicular to the thickness direction Y of the first current collector 111. The first film layer 112 is provided on a first surface 1131 of the first current collecting body 113 along the thickness direction Y. The first film layer 112 includes a main body region 1121 and a thinned region 1122. The thinned region 1122 is connected to the main body region 1121 and is located on the side of the main body region 1121 facing the first electrode tab 114. The main body region 1121 is thicker than the thinned region 1122.

[0102] The electrode assembly 10 also includes a first insulating member 14, which is connected to the first electrode sheet 11 and includes a first insulating portion 141 and a second insulating portion 142 arranged along a first direction X. The first insulating portion 141 is arranged on the side of the thinned region 1122 facing away from the first current collector 111. The second insulating portion 142 extends from the main region 1121 toward the thinned region 1122. The end of the second insulating portion 142 distal from the first insulating portion 141 extends beyond an end surface 1132 of the first current collector body 113 facing the first electrode tab 114. The thickness of the first insulating portion 141 is less than that of the second insulating portion 142. Along the thickness direction Y, the first insulating member 14 does not extend beyond the second surface 1121a of the main region 1121, distal from the first current collector body 113.

[0103] In some examples, the first electrode sheet 11 is a positive electrode sheet, the first current collector 111 is a positive electrode current collector, and the first film layer 112 is a positive electrode film layer and includes a positive electrode active material. In other examples, the first electrode sheet 11 is a negative electrode sheet, the first current collector 111 is a negative electrode current collector, and the first film layer 112 is a negative electrode film layer and includes a negative electrode active material.

[0104] In some examples, the first tab 114 and the first current collecting body 113 are integrally formed and can be formed by die cutting. In other examples, the first tab 114 and the first current collecting body 113 can also be formed independently and connected by welding or other suitable means.

[0105] The first current collecting body 113 includes two first surfaces 1131 that oppose each other along the thickness direction Y, with an end surface 1132 connecting the two first surfaces 1131. It will be appreciated that the first current collecting body 113 has a relatively small thickness, and the end surface 1132 is relatively small along the thickness direction Y. The end surface 1132 can be approximately a straight line. For example, the end surface 1132 can be formed during the cutting process of the first pole piece.

[0106] In some examples, one of the first surfaces 1131 may be provided with the first film layer 112 . In other examples, both of the first surfaces 1131 may be provided with the first film layer 112 .

[0107] One end of the thinned region 1122 close to the main region 1121 is directly connected to the main region 1121 .

[0108] The main body region 1121 may be a substantially uniform thickness structure, and the thinned region 1122 may be a substantially uniform thickness structure or a unequal thickness structure.

[0109] In some examples, along the direction from the first current collecting body 113 to the first electrode tab 114 , the thickness of the thinned region 1122 may decrease gradually or step by step.

[0110] In the embodiment of the present application, the thickness of the main region 1121 is greater than the thickness of the thinned region 1122 , which means that the average thickness of the main region 1121 is greater than the average thickness of the thinned region 1122 .

[0111] The first insulating member 14 can be connected to the first pole piece 11 by bonding, attaching or other appropriate methods.

[0112] The first insulating portion 141 covers at least a portion of the thinned region 1122 along the thickness direction Y. For example, the first insulating portion 141 may cover the entire thinned region 1122 or only a portion of the thinned region 1122 .

[0113] Along the thickness direction Y, the projection of the first insulating portion 141 is located within the projection of the thinned region 1122 , and the projection of the first insulating portion 141 does not overlap with the projection of the main region 1121 .

[0114] The end of the second insulating portion 142 closest to the first insulating portion 141 is directly connected to the first insulating portion 141. The end of the second insulating portion 142 further away from the first insulating portion 141 extends beyond the end surface 1132 of the first current collector 113. Along the thickness direction Y, the second insulating portion 142 covers the end surface 1132, thereby shielding burrs or metal particles formed on the end surface 1132 and reducing the risk of short circuits.

[0115] Along the thickness direction Y, the projection of the second insulating portion 142 may be separated from the projection of the thinned region 1122 , or may partially overlap with the projection of the thinned region 1122 .

[0116] The first insulating portion 141 is arranged on the side of the thinning zone 1122 away from the first current collector 111. The first insulating portion 141 and the thinning zone 1122 have overlapping thicknesses. In this application, the thickness of the first insulating portion 141 is set to be smaller than the thickness of the second insulating portion 142, which can reduce the total thickness of the first insulating portion 141 and the thinning zone 1122 after superposition, thereby saving space.

[0117] Along the thickness direction Y, the first insulating member 14 does not extend beyond the main region 1121 away from the second surface 1121a of the first current collecting body 113. The provision of the first insulating member 14 does not increase the thickness of the edge of the first electrode sheet 11, thereby reducing the possibility of bulging of the edge of the electrode assembly 10.

[0118] By providing a thinning region 1122, the embodiment of the present application can reduce the possibility of bulging of the die-cut edge of the first pole piece 11 after winding or stacking. In addition, the first insulating portion 141 with a smaller thickness is provided on the side of the thinning region 1122 facing away from the first current collector 111. The thinning space of the thinning region 1122 can be used to accommodate the first insulating portion 141, saving space. The second insulating portion 142 with a relatively larger thickness extends beyond the end face 1132 of the first current collector 113, which can reduce the possibility of the second insulating portion 142 being punctured by burrs or metal particles on the end face 1132, thereby reducing the risk of positive and negative pole conduction and improving the reliability of the battery cell 6.

[0119] In some embodiments, the second insulating portion 142 is located on a side of the thinned region 1122 away from the main region 1121 .

[0120] One end of the first insulating portion 141 close to the second insulating portion 142 extends to the edge of the first film layer 112 facing the first electrode tab 114 .

[0121] Along the thickness direction Y, the projections of the second insulating portion 142 and the thinned region 1122 do not overlap.

[0122] There is no thickness overlap between the second insulating part 142 and the thinning area 1122, which have relatively large thicknesses. Within the range of the second surface 1121a of the main area 1121, the thickness of the second insulating part 142 can be appropriately increased to improve its structural strength, further reduce the possibility of the second insulating part 142 being punctured by burrs or metal particles, and further improve the reliability of the battery cell 6.

[0123] In some embodiments, the electrode assembly 10 further includes a second insulating member 15. The second insulating member 15 and the first insulating member 14 are respectively disposed on both sides of the first electrode sheet 11 along the thickness direction Y. A portion of the second insulating member 15 is located on one side of the first current collector 113 along the thickness direction Y, along the direction of the first current collector 113 toward the first electrode tab 114. The second insulating member 15 extends beyond the end surface 1132 of the first current collector 113. The second insulating member 15 is connected to the second insulating portion 142.

[0124] The structure of the second insulating member 15 may be the same as or different from that of the first insulating member 14 .

[0125] The second insulating member 15 can be connected to the second insulating portion 142 by bonding, attaching or other appropriate methods.

[0126] Optionally, the portion of the second insulation member 15 beyond the end surface 1132 and the portion of the second insulation portion 142 beyond the end surface 1132 are connected.

[0127] In some examples, only one of the first surfaces 1131 of the first current collecting body 113 is provided with the first film layer 112, and a portion of the second insulation member 15 is directly provided on the other first surface 1131 of the first current collecting body 113.

[0128] In other examples, both of the first surfaces 1131 of the first current collecting body 113 are provided with the first film layer 112, and a portion of the second insulation member 15 can be provided on a side of the first film layer 112 away from the first current collecting body 113, or directly on one of the first surfaces 1131 of the first current collecting body 113.

[0129] In the direction of the first current collecting body 113 pointing to the first tab 114, both the second insulation portion 142 and the second insulation member 15 extend beyond the end surface 1132 of the first current collecting body 113, and the second insulation portion 142 and the second insulation member 15 can respectively shield burrs, metal particles and the like existing on the end surface 1132 from both sides of the end surface 1132 in the thickness direction Y, which is conducive to further reducing the risk of positive and negative conduction and improving the reliability of the battery monomer 6.

[0130] In some embodiments, the second insulation portion 142 includes a second insulation film layer 1421 and a second adhesive layer 1422, the second adhesive layer 1422 is provided on a side of the second insulation film layer 1421 facing the first tab 11, and at least a portion of the second adhesive layer 1422 is bonded to the second insulation member 15.

[0131] The second insulation film layer 1421 has a fourth surface facing the first tab 11, and the second adhesive layer 1422 can cover all of the fourth surface or only a portion of the fourth surface.

[0132] In some examples, along the thickness direction Y, the second adhesive layer 1422 can be provided only between the second insulation film layer 1421 and the second insulation member 15 and bonded to the second insulation member 15.

[0133] In other examples, along the thickness direction Y, a portion of the second adhesive layer 1422 can be provided between the second insulation film layer 1421 and the second insulation member 15 and bonded to the second insulation member 15; a portion of the second adhesive layer 1422 can be provided between the second insulation film layer 1421 and the first tab 114 and bonded to the first tab 114, and a portion of the second adhesive layer 1422 can also be provided between the second insulation film layer 1421 and a portion of the first surface 1131 and bonded to the first surface 1131.

[0134] The second insulating portion 142 is bonded to the second insulating member 15 via the second adhesive layer 1422, which helps to improve the connection stability between the first insulating member 14 and the second insulating member 15 and simplifies the assembly process. The second insulating film layer 1421 has a relatively high structural strength and is not easily punctured.

[0135] In some embodiments, reference Figure 9 and Figure 12 The first insulating portion 141 includes a first insulating film layer 1411 , and the first insulating film layer 1411 is attached to the third surface 1122 a of the thinned region 1122 away from the first current collecting body 113 .

[0136] The thickness of the first insulating film layer 1411 and the thickness of the second insulating film layer 1421 may be the same or different.

[0137] The first insulating film layer 1141 is directly attached to the third surface 1122 a , and there is no adhesive layer between the first insulating film layer 1141 and the third surface 1122 a .

[0138] Since there is no adhesion between the first insulating film layer 1141 and the third surface 1122 a , a certain gap can be formed between the first insulating film layer 1141 and the third surface 1122 a , which is conducive to filling the electrolyte so that the electrolyte contacts the thinned area 1122 .

[0139] The structural design of the first insulating part 141 without an adhesive layer can reduce the covering of the active material in the thinned area 1122 by the first insulating part 141 , which is beneficial to the capacity of the portion of the thinned area 1122 covered by the first insulating part 141 and reduces the impact on the capacity of the first electrode 11 .

[0140] In other embodiments, referring to Figure 13 The first insulating portion 141 includes a first insulating film layer 1411 and a first adhesive layer 1412. The first adhesive layer 1412 is disposed on the side of the first insulating film layer 1411 facing the first pole piece 11 and is bonded to the thinned area 1122. The thickness of the first adhesive layer 1412 is less than that of the second adhesive layer 1422.

[0141] Optionally, the thicknesses of the first adhesive layer 1412 and the second adhesive layer 1422 are substantially uniform, and the ratio of the thickness of the first adhesive layer 1412 to the thickness of the second adhesive layer 1422 may be 1 / 20 to 1 / 10.

[0142] The first adhesive layer 1412 is bonded to the thinned area 1122 , which can enhance the connection strength between the first insulating member 14 and the first pole piece 11 and reduce the phenomenon of the first insulating portion 141 lifting from the thinned area 1122 .

[0143] The relatively thin thickness of the first adhesive layer 1412 can reduce the possibility of the first adhesive layer 1412 overflowing toward the main body region 1121, thereby reducing the degree to which the first adhesive layer 1412 blocks the active material of the first film layer 112 and reduces the impact on the capacity of the first electrode 11. The relatively thick thickness of the second adhesive layer 1422 can increase the connection strength between the second insulating portion 142 and the second insulating member 15 or the first electrode 11, improve the structural strength of the second insulating portion 142, and further reduce the risk of the second insulating portion 142 being punctured by burrs or metal particles.

[0144] In some embodiments, the thickness of the first insulating film layer 1411 is less than or equal to the thickness of the second insulating film layer 1421 .

[0145] The first insulating film layer 1411 may have a substantially uniform thickness or a non-uniform thickness. For example, the thickness of the first insulating film layer 1411 may increase gradually or step by step along the direction from the first current collecting body 113 to the first electrode tab 114 .

[0146] In the embodiment of the present application, the thickness of the first insulating film layer 1411 is less than or equal to the thickness of the second insulating film layer 1421 , which means that the average thickness of the first insulating film layer 1411 is less than or equal to the average thickness of the second insulating film layer 1421 .

[0147] The first insulating film layer 1411 is relatively thin, which helps reduce the overall thickness and occupied space of the first insulating portion 141. The second insulating film layer 1421 is relatively thick, which helps increase the structural strength of the second insulating portion 142 and further reduces the risk of the second insulating portion 142 being punctured by burrs or metal particles.

[0148] In some embodiments, the first current collector 113 has two first surfaces 1131 oppositely disposed along the thickness direction Y. The first pole piece 11 includes two first film layers 112 symmetrically disposed on the two first surfaces 1131. The first insulating member 14 and the second insulating member 15 are symmetrically disposed.

[0149] The two first film layers 112 are symmetrically arranged and have the same structure. Both first film layers 112 have a main region 1121 and a thinning region 1122. The main regions 1121 of the two first film layers 112 are symmetrically arranged, and the thinning regions 1122 of the two first film layers 112 are symmetrically arranged.

[0150] The first insulating member 14 and the second insulating member 15 are symmetrically arranged and have the same structure. The second insulating member 15 has a third insulating portion 151 and a fourth insulating portion 152. The first insulating portion 141 and the third insulating portion 151 are symmetrically arranged, and the second insulating portion 142 and the fourth insulating portion 152 are symmetrically arranged.

[0151] The second insulating member 15 is located on the side of one of the first film layers 112 facing away from the first current collector 111. The third insulating portion 151 is located on the side of the thinned region 1122 of the first film layer 112 facing away from the first current collector 111. Along the direction from the main region 1121 toward the thinned region 1122, the end of the fourth insulating portion 152 distal from the third insulating portion 151 extends beyond the end surface 1132 of the first current collector body 113. The thickness of the third insulating portion 151 is less than that of the fourth insulating portion 152. Along the thickness direction Y, the second insulating member 15 does not extend beyond the main region 1121 of the first film layer 112, distal from the second surface 1121a of the first current collector body 113.

[0152] The third insulating portion 151 has the same structure as the first insulating portion 141, which will not be described in detail here. The fourth insulating portion 152 has the same structure as the second insulating portion 142, which will not be described in detail here.

[0153] A first film layer 112 is provided on both sides of the first current collector 113 along the thickness direction Y, which can increase the coverage area of ​​the active material and improve the capacity of the first pole piece 11. Neither of the two insulating members increases the thickness of the edge of the first pole piece 11, reducing the possibility of bulging at the edge of the electrode assembly 10. Both insulating members are provided with thicker insulating portions (second insulating portion 142 and fourth insulating portion 152), which are not easily punctured by burrs or metal particles, which helps to reduce the risk of conduction between the first pole piece 11 and the second pole pieces 12 located on both sides thereof, thereby improving the reliability of the battery cell 6.

[0154] In some embodiments, reference Figures 8 to 10 Along the thickness direction Y, the end of the thinned region 1122 facing away from the main region 1121 is flush with the end of the first current collecting body 113 facing the first electrode tab 114 . The second insulating portion 142 is provided on the outer side of the first current collecting body 113 facing the first electrode tab 114 .

[0155] In other words, the end of the thinned region 1122 away from the main region 1121 may extend to the end surface 1132 . The first film layer 112 may cover the entire area of ​​the first surface 1131 .

[0156] The second insulating portion 142 is disposed on the outer side of the first current collecting body 113 facing the first electrode tab 114. Along the thickness direction Y, the projection of the second insulating portion 142 does not overlap with the projection of the first current collecting body 113.

[0157] Along the thickness direction Y, the second insulating portion 142 may cover a portion of the first electrode tab 114 , or may not cover the first electrode tab 114 .

[0158] In the embodiment of the present application, the end of the thinned area 1122 away from the main area 1121 is flush with the end of the first current collecting body 113 facing the first electrode tab 114, which can maximize the area of ​​the first film layer 112, increase the coverage area of ​​the active material, and improve the capacity of the first electrode 11.

[0159] In some embodiments, the end surface 1132 includes a tab lead-out region 1132a and a non-tab lead-out region 1132b. The first tab 114 extends only from the tab lead-out region 1132a and protrudes from the second insulating portion 142 in a direction away from the first current collecting body 113. The second insulating portion 142 is provided only outside the non-tab lead-out region 1132b along the first direction X.

[0160] There can be one or more tab lead-out regions 1132a. For example, the number of tab lead-out regions 1132a corresponds to the number of first tabs 114. After the first tab 114 is cut off along the end surface 1132, the tab lead-out regions 1132a are exposed.

[0161] There can be one or more non-tab lead-out regions 1132b.

[0162] Illustratively, there are multiple tab lead-out regions 1132a and multiple non-tab lead-out regions 1132b, and the tab lead-out regions 1132a and the non-tab lead-out regions 1132b are alternately arranged.

[0163] The first tab 114 protrudes from the second insulating portion 142 to facilitate connection with other conductive structures, thereby reducing the risk of interference between the second insulating portion 142 and the conductive structures.

[0164] The second insulating portion 142 is only provided on the outside of the non-tab lead-out area 1132b along the first direction X. Along the thickness direction Y, the second insulating portion 142 does not cover the first tab 114, thereby increasing the length by which the first tab 114 can be connected to the conductive structure, further reducing the risk of interference between the second insulating portion 142 and the conductive structure.

[0165] In other embodiments, the second insulating portion 142 includes a first extension portion 142a and a second extension portion 142b, the first extension portion 142a is arranged on the outside of the non-tab lead-out area 1132b along the first direction X, and the second extension portion 142b is arranged on the outside of the tab lead-out area 1132a along the first direction X, and covers a portion of the first tab 114 along the thickness direction Y.

[0166] For example, a plane parallel to the first direction X and passing through the junction of the tab lead-out region 1132 a and the non-tab lead-out region 1132 b may be the interface between the first extension portion 142 a and the second extension portion 142 b .

[0167] In the first direction X, the size of the first extending portion 142 a and the size of the second extending portion 142 b may be equal or unequal.

[0168] In some examples, the dimension of the first extending portion 142 a along the first direction X is equal to the dimension of the second extending portion 142 b along the first direction X, and the second insulating portion 142 is configured with equal width for easy molding.

[0169] The first extension portion 142 a may include only the second insulating film layer 1421 , or may include both the second insulating film layer 1421 and the second adhesive layer 1422 .

[0170] In some examples, the first extension portion 142 a includes both a second insulating film layer 1421 and a second adhesive layer 1422 , and the first insulating member 14 is bonded to the second insulating member 15 via the second adhesive layer 1422 of the first extension portion 142 a .

[0171] The second extending portion 142 b may include only the second insulating film layer 1421 , or may include both the second insulating film layer 1421 and the second adhesive layer 1422 .

[0172] In some examples, the second extension portion 142b includes both a second insulating film layer 1421 and a second adhesive layer 1422. The second insulating portion 142 is bonded to the first pole tab 114 through the second adhesive layer 1422 of the second extension portion 142b, which helps to increase the structural strength of the first pole tab 114 and reduce the risk of cracking of the first pole tab 114 during bending.

[0173] Along the thickness direction Y, the first extension portion 142 a may cover the non-tab lead-out region 1132 b to shield burrs or metal particles on the non-tab lead-out region 1132 b .

[0174] Along the thickness direction Y, the second extension portion 142b can cover the root portion of the first electrode tab 114 near the first current collector 113, thereby shielding burrs at the root portion of the first electrode tab 114 and reducing the risk of cracking at the root portion of the first electrode tab 114. Furthermore, the risk of the first electrode tab 114 being inserted upside down between the first electrode sheet 11 and the second electrode sheet 12 when bent can be reduced.

[0175] In some embodiments, reference Figure 11 and Figure 12The first surface 1131 includes a coated area 1131a and an uncoated area 1131b arranged along the first direction X. One end of the uncoated area 1131b is connected to the end surface 1132, and the other end is connected to the coated area 1131a. The coated area 1131a is coated with the first film layer 112, and the uncoated area 1131b is not coated with the first film layer 112. Along the thickness direction Y, the second insulating portion 142 covers the uncoated area 1131b.

[0176] Only a portion of the first surface 1131 is coated with the first film layer 112, and the edge of the first surface 1131 near the end surface 1132 is not coated with the first film layer 112, forming an uncoated area 1131b. In this way, the first film layer 112 and the end surface 1132 can be spaced apart along the first direction X.

[0177] Along the thickness direction Y, the second insulating portion 142 completely covers the uncoated area 1131b, preventing the uncoated area 1131b from being directly exposed to the electrolyte and causing side reactions. Furthermore, the possibility of electrical connection between the uncoated area 1131b and the second electrode 12 is reduced, thereby reducing the risk of short circuits and improving reliability.

[0178] In this embodiment of the present application, by providing an uncoated area 1131b on the first surface 1131, the contact area between the first current collector 113 and the first insulating member 14 is increased, reducing the risk of the first insulating member 14 falling off, and improving its stability and reliability. The end surface 1132 and the first film layer 112 are spaced apart along the first direction X, which reduces the risk of cutting the first film layer 112 during the cutting process of the first electrode sheet 11 and reduces the waste of active material.

[0179] In some embodiments, reference Figure 9 and Figure 12 The second insulating portion 142 includes a second insulating film layer 1421 and a second adhesive layer 1422 . The second adhesive layer 1422 is disposed on a side of the second insulating film layer 1421 facing the first electrode 11 . At least a portion of the second adhesive layer 1422 is bonded to the uncoated area 1131 b .

[0180] The second insulating portion 142 may include a covering portion having one end connected to the first insulating portion 141 along the first direction X and the other end extending to the end surface 1132. Along the thickness direction Y, a projection of the covering portion overlaps with a projection of the uncoated region 1131b.

[0181] The covering portion may include both a second insulating film layer 1421 and a second adhesive layer 1422 , and may be bonded to the uncoated region 1131 b via the second adhesive layer 1422 .

[0182] Optionally, the second insulating part 142 further comprises a first extension part 142a and a second extension part 142b, the first extension part 142a is arranged at the outer side of the non-tab lead-out area 1132b along the first direction X, and the second extension part 142b is arranged at the outer side of the tab lead-out area 1132a along the first direction X and covers a part of the first tab 114 along the thickness direction Y.

[0183] The first end of the first extension part 142a close to the non-tab lead-out area 1132b and the second end of the second extension part 142b close to the tab lead-out area 1132a are both connected to the covering part.

[0184] The second insulating part 142 is adhered to the uncoated area 1131b by the second adhesive layer 1422, which can improve the connection strength and stability between the first insulating part 14 and the first tab 11, and reduce the possibility of the first insulating part 14 falling off.

[0185] In some embodiments, along the first direction X, the first insulating part 141 is arranged spaced apart from the main body area 1121.

[0186] The first insulating part 141 and the main body area 1121 do not overlap in the thickness direction Y, and there is no thickness overlap, which is beneficial to improve the space utilization.

[0187] The first insulating part 141 is arranged spaced apart from the main body area 1121, and along the thickness direction Y, the first insulating part 141 only covers a part of the thinned area 1122, which is beneficial to the more active substances of the first film layer 112 to contact the electrolyte, and is beneficial to reduce the capacity loss of the battery monomer 6.

[0188] In some embodiments, the thickness of the second insulating part 142 is less than the thickness of the main body area 1121.

[0189] The second insulating part 142 and the main body area 1121 can both be a structure with substantially uniform thickness.

[0190] Along the direction in which the first current collecting main body 113 points to the first film layer 112, the main body area 1121 can protrude beyond the surface of the second insulating part 142 away from the first current collecting main body 113, which is beneficial to reduce the possibility of the die-cut edge of the electrode assembly 10 being raised.

[0191] In some embodiments, the thickness of the first insulating part 141 is less than the maximum thickness difference between the main body area 1121 and the thinned area 1122.

[0192] The first insulating part 141 can be a structure with substantially uniform thickness, or a structure with non-uniform thickness. Illustratively, along the direction in which the first current collecting main body 113 points to the first tab 114, the thickness of the first insulating part 141 gradually increases or increases in sections.

[0193] The main body region 1121 may have a substantially uniform thickness. The thinned region 1122 may have a substantially uniform thickness or a non-uniform thickness. For example, the thinned region 1122 gradually decreases or decreases in sections along the direction from the first current collecting body 113 to the first electrode tab 114.

[0194] The thinned region 1122 has a minimum thickness at one end thereof away from the main region 1121 . The maximum thickness difference between the main region 1121 and the thinned region 1122 is the difference between the thickness of the main region 1121 and the minimum thickness of the thinned region 1122 .

[0195] In the embodiment of the present application, the thickness of the first insulating portion 141 is less than the maximum thickness difference between the main region 1121 and the thinning region 1122 , which means that the thickness at any position of the first insulating portion 141 is less than the maximum thickness difference between the main region 1121 and the thinning region 1122 .

[0196] In some embodiments, the second pole piece 12 includes a second current collector 121 and a second film layer 122. The second film layer 122 has the same structure as the first film layer 112 and is not further described here. The electrode assembly 10 also includes a third insulating member connected to the second pole piece 12. The third insulating member has the same structure as the first insulating member 14 and is not further described here.

[0197] According to the second aspect of the present application, an embodiment of the present application further provides a battery device 2, which includes a plurality of battery cells 6 provided according to any embodiment of the present application.

[0198] According to a third aspect of the present application, an embodiment of the present application further provides an electrical device, which includes a battery device 2 provided according to any embodiment of the present application, and the battery device 2 is used to provide electrical energy.

[0199] An embodiment of the present application provides a battery cell 6, which includes a housing 20 and an electrode assembly 10 housed within the housing 20. The electrode assembly 10 includes a first electrode sheet 11 and a second electrode sheet 12 of opposite polarity. The first electrode sheet 11 includes a first current collector 111 and a first film layer 112. The first current collector 111 includes a first current collector body 113 and a first electrode tab 114. The first electrode tab 114 extends from an end of the first current collector body 113 along a first direction X, which is perpendicular to the thickness direction Y of the first current collector 111. The first film layer 112 is disposed on a first surface 1131 of the first current collector body 113 along the thickness direction Y. The first film layer 112 includes a main body region 1121 and a thinned region 1122. The thinned region 1122 is connected to the main body region 1121 and is located on the side of the main body region 1121 facing the first electrode tab 114. The main body region 1121 is thicker than the thinned region 1122. The electrode assembly 10 also includes a first insulating member 14, which is connected to the first electrode sheet 11 and includes a first insulating portion 141 and a second insulating portion 142 arranged along a first direction X. The first insulating portion 141 is arranged on the side of the thinned region 1122 facing away from the first current collector 111. The second insulating portion 142 extends from the main region 1121 toward the thinned region 1122. The end of the second insulating portion 142 distal from the first insulating portion 141 extends beyond an end surface 1132 of the first current collector body 113 facing the first electrode tab 114. The thickness of the first insulating portion 141 is less than that of the second insulating portion 142. Along the thickness direction Y, the first insulating member 14 does not extend beyond the second surface 1121a of the main region 1121, distal from the first current collector body 113.

[0200] The thickness of the first insulating portion 141 is smaller than the difference in thickness between the main region 1121 and the thinned region 1122 . The thickness of the second insulating portion 142 is smaller than the thickness of the main region 1121 .

[0201] In some examples, the first insulating portion 141 does not have an adhesive layer, and the second insulating portion 142 has an adhesive layer.

[0202] In other examples, the first insulating portion 141 and the second insulating portion 142 both include an adhesive layer, and the thickness of the adhesive layer of the first insulating portion 141 is smaller than the thickness of the adhesive layer of the second insulating portion 142 .

[0203] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some or all of the technical features can be replaced equivalently. Such modifications or replacements do not change the essence of the corresponding technical solutions, which should be covered in the scope of the present application. In particular, the technical features mentioned in each embodiment can be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that: It comprises a housing and an electrode assembly contained in the housing, wherein the electrode assembly comprises a first pole piece and a second pole piece with opposite polarities; The first electrode sheet includes a first current collector and a first film layer. The first current collector includes a first current collecting body and a first tab. The first tab is extended from an end of the first current collecting body along a first direction. The first direction is perpendicular to the thickness direction of the first current collector. The first film layer is provided on a first surface of the first current collecting body along the thickness direction. The first film layer includes a main body region and a thinning region. The thinning region is connected to the main body region and is located on a side of the main body region facing the first tab. The thickness of the main body region is greater than the thickness of the thinning region. The electrode assembly also includes a first insulating member, which is connected to the first pole piece and includes a first insulating portion and a second insulating portion arranged along the first direction. The first insulating portion is arranged on the side of the thinning area away from the first current collector, and along the direction of the main area pointing to the thinning area, the second insulating portion has an end away from the first insulating portion that exceeds the end surface of the first current collector facing the first pole ear, and the thickness of the first insulating portion is less than the thickness of the second insulating portion; along the thickness direction, the first insulating member does not exceed the second surface of the main area away from the first current collector.

2. The battery cell according to claim 1, wherein: The second insulating portion is located on a side of the thinned region away from the main region.

3. The battery cell according to claim 1, wherein: The electrode assembly further includes a second insulating member, the second insulating member and the first insulating member are respectively provided on both sides of the first electrode sheet along the thickness direction, a portion of the second insulating member is located on one side of the first current collector along the thickness direction, and extends beyond the end surface in a direction from the first current collector to the first electrode tab; The second insulating member is connected to the second insulating portion.

4. The battery cell according to claim 3, characterized in that The second insulating portion includes a second insulating film layer and a second adhesive layer. The second adhesive layer is provided on a side of the second insulating film layer facing the first pole piece. At least a portion of the second adhesive layer is adhered to the second insulating member.

5. The battery cell according to claim 4, characterized in that The first insulating portion includes a first insulating film layer, and the first insulating film layer is attached to a third surface of the thinned region facing away from the first current collecting body.

6. The battery cell according to claim 4, characterized in that The first insulating portion includes a first insulating film layer and a first adhesive layer, wherein the first adhesive layer is provided on a side of the first insulating film layer facing the first pole piece and is bonded to the thinned area; The thickness of the first adhesive layer is smaller than the thickness of the second adhesive layer.

7. The battery cell according to claim 5 or 6, characterized in that: The thickness of the first insulating film layer is less than or equal to the thickness of the second insulating film layer.

8. The battery cell according to claim 3, characterized in that The first current collecting body has two first surfaces arranged opposite to each other along the thickness direction, and the first pole piece includes two first film layers, which are symmetrically arranged on the two first surfaces; The first insulating member and the second insulating member are symmetrically arranged.

9. The battery cell according to claim 1, characterized in that Along the thickness direction, an end of the thinned region away from the main region is flush with an end of the first current collecting body facing the first electrode tab; The second insulating portion is provided on an outer side of the first current collecting body facing the first electrode tab.

10. The battery cell according to claim 9, characterized in that The end surface includes a tab lead-out area and a non-tab lead-out area, the first tab extends only from the tab lead-out area and protrudes from the second insulating portion in a direction away from the first current collecting body; The second insulating portion is only provided on the outer side of the non-tab lead-out region along the first direction.

11. The battery cell according to claim 1, characterized in that The first surface includes a coated area and an uncoated area arranged along the first direction, one end of the uncoated area is connected to the end surface, and the other end is connected to the coated area, the coated area is coated with the first film layer, and the uncoated area is not coated with the first film layer; The second insulating portion covers the uncoated region along the thickness direction.

12. The battery cell according to claim 11, characterized in that The second insulating portion includes a second insulating film layer and a second adhesive layer. The second adhesive layer is provided on a side of the second insulating film layer facing the first pole piece. At least a portion of the second adhesive layer is adhered to the uncoated area.

13. The battery cell according to claim 1, characterized in that The end surface includes a tab lead-out area and a non-tab lead-out area, the first tab extends only from the tab lead-out area and protrudes from the second insulating portion in a direction away from the first current collecting body; The second insulating portion includes a first extension portion and a second extension portion. The first extension portion is arranged outside the non-tab lead-out area along the first direction. The second extension portion is arranged outside the tab lead-out area along the first direction and covers a portion of the first tab along the thickness direction.

14. The battery cell according to claim 1, characterized in that Along the first direction, the first insulating portion is spaced apart from the main body region.

15. The battery cell according to claim 1, characterized in that The thickness of the second insulating portion is smaller than the thickness of the main body region; and / or The thickness of the first insulating portion is smaller than a maximum thickness difference between the main region and the thinned region.

16. A battery device, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 15.

17. An electrical device, characterized in that: The battery device according to claim 16 is included, and is used to provide electrical energy.

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