Battery cell, battery device, and electric device

Abstract

This application discloses a battery cell, a battery device, and an electrical appliance. The battery cell includes a housing, an electrode assembly, and a fixing member. The electrode assembly is disposed in the housing and includes multiple wound electrode sheets. The electrode assembly includes an electrode body and electrode tabs. The electrode body has a first end and a second end disposed opposite to each other along a first direction. The electrode tabs are connected to the first end. The electrode body includes a flat region and a bent region located on both sides of the flat region along a second direction. In the flat region, the electrode sheets are stacked along a third direction, and the first direction, the second direction, and the third direction intersect each other in pairs. The fixing member includes a first sub-component disposed at the first end. The two opposite ends of the fixing member are respectively connected to the two opposite side surfaces of the electrode body in the third direction to limit the size of the electrode body in the third direction. The battery cell provided by the embodiments of this application can improve reliability and processing yield.

Description

Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell, battery device, and electrical equipment. Background Technology

[0002] With the development of new energy technologies, batteries are being used more and more widely, for example in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools.

[0003] The development of battery technology must take into account multiple design factors. For example, improving the reliability of individual battery cells and increasing processing yield is an important research direction in the battery field. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical appliance that can improve reliability and processing yield.

[0005] In a first aspect, this application provides a battery cell, including a housing, an electrode assembly, and a fixing member; the electrode assembly is disposed in the housing and includes a plurality of wound electrode sheets, the electrode assembly includes an electrode body and electrode tabs, the electrode body has a first end and a second end disposed opposite to each other along a first direction, the electrode tabs are connected to the first end, the electrode body includes a flat region and a bent region located on both sides of the flat region along a second direction, in the flat region, the electrode sheets are stacked along a third direction, and the first direction, the second direction, and the third direction are intersected in pairs; the fixing member includes a first sub-component disposed at the first end, and the two opposite ends of the fixing member are respectively connected to the two opposite side surfaces of the electrode body in the third direction to limit the size of the electrode body in the third direction.

[0006] In the technical solution of this application embodiment, the battery cell includes a housing, an electrode assembly disposed in the housing, and a fixing member disposed on the electrode assembly. The electrode assembly is formed by winding multiple electrode sheets, and a tab is provided at one end in a first direction. The fixing member has a first sub-component connected to two opposite surfaces of the electrode assembly. The first sub-component can limit the thickness of the electrode assembly by its extension dimension in this direction. This can reduce the possibility that the wound electrode assembly has an opening in the center, thereby reducing the possibility of tab folding and separator folding problems. This reduces the risk of short circuit caused by anode-cathode overlap, and at the same time reduces the expansion of the electrode assembly during operation, improving the reliability of the battery cell.

[0007] According to some embodiments of this application, the electrode assembly includes two tabs spaced apart along a second direction, and a first sub-component disposed between the two tabs. The size of the first sub-component in the second direction is less than or equal to the distance between the two tabs. By positioning the first sub-component close to the center of the electrode assembly in the second direction, the possibility of interference between the first sub-component and the tabs is reduced.

[0008] According to some embodiments of this application, the difference between the dimension of the first sub-component in the second direction and the distance between the two tabs is 0-10 mm. This ensures that the dimension of the first sub-component is adapted to the tab spacing of the electrode assembly.

[0009] According to some embodiments of this application, the fixing member further includes a second sub-member disposed at the second end, with its opposite ends respectively connected to the two opposing side surfaces of the electrode body in a third-direction orientation. By simultaneously providing fixing members at opposite ends of the electrode assembly, the possibility of an opening forming at the center of the electrode assembly is further reduced.

[0010] According to some embodiments of this application, both the first sub-component and the second sub-component include a hollow area and two connecting areas located on both sides of the hollow area along a third direction. The two connecting areas are respectively connected to the opposite side surfaces of the electrode body in the third direction. The hollow area is provided with multiple through holes extending along the thickness direction of the fixing member. The hollow area reduces the influence of the fixing member on electrolyte wetting and electrode assembly venting.

[0011] According to some embodiments of this application, along a third direction, the size of the hollowed-out area is greater than or equal to the size of the electrode body. Along a first direction, the orthographic projection of the connection area of ​​the first sub-component forms a first pattern, and the orthographic projection of the connection area of ​​the second sub-component forms a second pattern. Both the first and second patterns are offset from and connected to the orthographic projection of the electrode body. This arrangement ensures that the hollowed-out areas in the two sub-components are directly opposite the electrode assembly, further reducing the possibility of obstruction by the fixing components.

[0012] According to some embodiments of this application, along the second direction, the size of the second sub-component is less than or equal to the size of the straight area, and along the first direction, the orthographic projection of the second sub-component is offset from the orthographic projection of the bending area. This offsetting of the second sub-component from the bending area reduces the possibility of redundancy in the second sub-component and a decrease in the robustness of the connection with the electrode assembly.

[0013] According to some embodiments of this application, along the second direction, the difference between the size of the second sub-component and the size of the straight area is 0-4mm, and the minimum distance between the opposite two edges of the second sub-component along the second direction and the opposite two edges of the straight area in that direction is 0-2mm. This ensures that the second sub-component has a suitable length dimension for easy installation.

[0014] According to some embodiments of this application, the fastener is bonded to the electrode assembly. The fastener includes a laminated insulating carrier layer and a high-temperature resistant adhesive layer, with the high-temperature resistant adhesive layer located between the insulating carrier layer and the electrode assembly. This provides the fastener with good insulation properties and improves the reliability of the bonded connection.

[0015] According to some embodiments of this application, the thickness of the fastener is 0.05μm-0.2μm. This allows the fastener to have a suitable thickness dimension.

[0016] Secondly, according to the embodiments of this application, a battery device is provided, including a housing and a battery cell as described in any embodiment of the first aspect, wherein the battery cell is disposed in the housing.

[0017] Thirdly, according to embodiments of this application, an electrical device is provided, including the battery device in any embodiment of the second aspect, the battery device being used to provide electrical energy. Attached Figure Description

[0018] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0019] Figure 1 A simplified schematic diagram of a vehicle provided for some embodiments of this application;

[0020] Figure 2 Explosion-proof diagrams of battery devices provided in some embodiments of this application;

[0021] Figure 3 This is an exploded schematic diagram of a battery cell provided in some embodiments of this application;

[0022] Figure 4 A partial structural schematic diagram of a battery cell provided in some embodiments of this application;

[0023] Figure 5 A top view schematic diagram of a partial structure of a battery cell provided in some embodiments of this application;

[0024] Figure 6 This is a bottom view of a partial structure of a battery cell provided in some embodiments of this application.

[0025] Figure label:

[0026] 1000 - Vehicles;

[0027] 100 - Individual battery cell; 200 - Battery assembly; 300 - Controller; 400 - Motor;

[0028] 10 - Housing; 20 - Electrode assembly; 30 - Fixture; 40 - Enclosure;

[0029] 21-Electrode body; 22-Electrode tab; 31-First sub-component; 32-Second sub-component;

[0030] 211 - First end; 212 - Second end; 213 - Straight area; 214 - Bending area; 311 - Hollowed-out area; 312 - Connecting area;

[0031] X - First direction; Y - Second direction; Z - Third direction. Detailed Implementation

[0032] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0034] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0035] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0036] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0037] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0038] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0039] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0040] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0041] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0042] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0043] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0044] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0045] As an example, the positive current collector can be a metal foil or a composite current collector.

[0046] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0047] As an example, the negative electrode current collector can be made of metal foil, foam metal, or composite current collector.

[0048] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0049] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0050] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0051] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0052] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0053] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0054] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene and polyvinylidene fluoride, and ceramic.

[0055] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0056] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0057] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0058] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0059] In some embodiments, the housing may be provided with functional components such as electrode terminals. The electrode terminals can be used to electrically connect to the electrode assembly for outputting or inputting electrical energy into the battery cell.

[0060] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0061] The battery device mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity.

[0062] In some embodiments, the battery device can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0063] In some embodiments, the battery device may be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0064] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0065] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0066] A battery cell typically includes a casing and electrode assemblies and electrolyte disposed within the casing. The electrode assembly usually includes a positive electrode, a negative electrode, and a separator for forming an insulating structure between the two. These three components can be manufactured into the desired electrode assembly by winding or stacking. Among them, wound electrode assemblies are widely used due to their high production efficiency, high structural strength, and low internal resistance.

[0067] In existing battery cell manufacturing processes, negative electrode sheets, separators, and positive electrode sheets are typically stacked in a specific order, then fixed at one end by a winding needle, and finally wound into shape by rotating or flipping the needle. Furthermore, to reduce the stress difference between the positive and negative electrode sheets during winding, they are usually positioned on the same side of the winding needle. The assembled structure after winding typically needs to be pressed under pressure to reduce its dimensions in a certain direction, forming a shape with a straight center and bent ends. This reduces the thickness of the electrode assembly and facilitates the connection of multiple electrode assemblies.

[0068] Based on this, the applicant discovered that the electrode assembly wound in the above manner is prone to a structure in which the electrode pieces are directly connected in the innermost circle. That is, the positive electrode piece / negative electrode piece is located in the innermost circle, and after winding, the two electrode pieces on both sides are directly connected without any separator for bonding. As a result, the bonding force on both sides of the electrode assembly along this direction is insufficient, and an opening is prone to appear in the center, that is, at the original fixed position of the winding needle. This opening leads to an increase in the distance between the tabs extending from both sides of the opening. During the winding process or during movement after winding, the tabs are prone to folding, resulting in short circuits or damage to the electrode assembly.

[0069] In view of this, the present application provides a technical solution that improves the reliability of battery cells and increases processing yield by setting a fixing member on the electrode assembly to limit its thickness.

[0070] The technical solutions described in this application are applicable to battery devices and electrical equipment using battery devices. Electrical equipment includes, for example, mobile phones, portable devices, laptops, electric vehicles, electric cars, ships, spacecraft, electric toys, and power tools. Spacecraft include, for example, airplanes, rockets, space shuttles, and spacecraft. Electric toys include, for example, stationary or mobile electric toys, specifically, game consoles, electric car toys, electric ship toys, and electric airplane toys. Power tools include, for example, metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, specifically, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers.

[0071] The battery cells described in this application are not limited to the electrical devices described above, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0072] Please see Figure 1 , Figure 1This is a simplified schematic diagram of a vehicle provided in some embodiments of this application. The vehicle can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 200 can be installed inside the vehicle 1000; specifically, for example, the battery device 200 can be installed at the bottom, front, or rear of the vehicle 1000. The battery device 200 can be used to power the vehicle 1000; for example, the battery device 200 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 300 and a motor 400. The controller 300, for example, is used to control the battery to supply power to the motor 400. The battery device 200 can be used for starting the vehicle 1000, navigation, etc. Of course, the battery can also be used to drive the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide propulsion for the vehicle 1000.

[0073] Figure 2 This is an exploded schematic diagram of a battery device provided in some embodiments of this application. For example... Figure 2 As shown, the battery device includes a housing and individual battery cells, with the individual battery cells housed within the housing.

[0074] The housing 40 is used to accommodate the battery cell 100, and the housing 40 can have various structures. In some embodiments, the housing 40 may include a first housing portion 41 and a second housing portion 42, which overlap each other, and together define a receiving portion 43 for accommodating the battery cell 100. The second housing portion 42 may be a hollow structure with one end open, and the first housing portion 41 may be a plate-like structure, with the first housing portion 41 covering the open side of the second housing portion 42 to form a housing 40 with the receiving portion 43; alternatively, both the first housing portion 41 and the second housing portion 42 may be hollow structures with one side open, with the open side of the first housing portion 41 covering the open side of the second housing portion 42 to form a housing 40 with the receiving portion 43. Of course, the first housing portion 41 and the second housing portion 42 can be various shapes, such as cylinders, cuboids, etc.

[0075] In a battery, there can be one or more battery cells 100. If there are multiple battery cells 100, they can be connected in series, in parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 100 are connected in both series and parallel configurations. Multiple battery cells 100 can be directly connected in series, in parallel, or in a mixed configuration, and then the whole assembly of multiple battery cells 100 is housed in the housing 40. Alternatively, multiple battery cells 100 can first be connected in series, in parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed configuration to form a whole assembly, which is then housed in the housing 40.

[0076] In some embodiments, there are multiple battery cells 100, which are first connected in series, parallel, or mixed to form a battery module. The multiple battery modules are then connected in series, parallel, or mixed to form a whole and housed within the housing 40.

[0077] Next, we will combine the appendix Figure 3 To be continued Figure 6 The structure of the battery cell 100, the battery device 200, and the electrical equipment is described.

[0078] Please refer to the following: Figure 3 and Figure 4 , Figure 3 This is an exploded view of a single battery cell provided in some embodiments of this application. Figure 4 This is a partial structural diagram of a battery cell provided in some embodiments of this application.

[0079] In a first aspect, this application provides a battery cell 100, including a housing, an electrode assembly 20, and a fixing member 30. The electrode assembly 20 is disposed in the housing and includes a plurality of wound electrode sheets. The electrode assembly 20 includes an electrode body 21 and an electrode tab 22. The electrode body 21 has a first end 211 and a second end 212 disposed opposite to each other along a first direction X. The electrode tab 22 is connected to the first end 211. The electrode body 21 includes a flat region 213 and a bent region 214 located on both sides of the flat region 213 along a second direction Y. In the flat region 213, the electrode sheets are stacked along a third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other. The fixing member 30 includes a first sub-component 31 disposed at the first end 211. The two opposite ends of the fixing member 30 are respectively connected to the two opposite side surfaces of the electrode body 21 in the third direction Z to limit the size of the electrode body 21 in the third direction Z.

[0080] This application provides a battery cell 100, including a housing 10 for providing containment, protection and support, and an electrode assembly 20 for realizing electrical functions. The housing 10 encloses a containment cavity, and the electrode assembly 20 is disposed in the containment cavity. At the same time, an electrolyte may also be disposed in the containment cavity, and the electrode assembly 20 is immersed in the electrolyte.

[0081] The electrode assembly 20 includes an electrode body 21 and tabs 22 extending from the electrode body 21. The electrode body 21 can be formed by winding multiple electrode sheets and spacers together, with each electrode sheet protruding in the same direction and stacked to form the tabs 22. The electrode body 21 has a first end 211 and a second end 212 opposite each other in a first direction X. The multiple tabs 22 can all be connected to the first end 211 of the electrode body 21, or the multiple tabs 22 can be respectively connected to the first end 211 and the second end 212 of the electrode body 21.

[0082] Meanwhile, the electrode body 21 may be formed by winding an electrode sheet, and may have a flat region 213 and a bent region 214 located on opposite sides of the flat region 213 along the second direction Y. Exemplarily, the electrode sheet is divided into multiple alternately arranged first and second regions. In the flat region 213, multiple first regions of multiple electrodes are stacked along the third direction Z. In the bent region 214, multiple second regions of multiple electrodes are bent and stacked. The first direction X, the second direction Y, and the third direction Z are arranged intersecting each other, or more preferably perpendicularly to each other.

[0083] The fastener 30 is disposed on the electrode assembly 20, including a first sub-component 31 located at the first end 211. The first sub-component 31 may extend along the second direction Y. The second direction Y is denoted as the length direction of the first sub-component 31. Its two opposite ends in the width direction perpendicular to it are respectively connected to the two opposite surfaces of the electrode assembly 20 in the third direction Z. The connection may be adhesive, snap-fit, or press-fit. By limiting the length dimension of the first sub-component 31 itself, a force along the third direction Z can be applied to the electrode assembly 20 accordingly.

[0084] The electrode in the electrode assembly 20 has a center when it is wound. With this center as the boundary, the electrode on both sides located in the third direction Z is divided into a first electrode group and a second electrode group. The fixing member 30 is used to press the first electrode group and the second electrode group together and connect them, that is, to limit the overall size of the electrode body 21 in the third direction Z.

[0085] Furthermore, the fastener 30 can be a rigid limiting buckle with a certain structural strength to improve the stability and reliability of the compression and fixing force on the first electrode group and the second electrode group; or, the fastener 30 can be a flexible adhesive tape to facilitate installation and require less space while effectively reducing the central opening, which means that the battery cell 100 can maintain a high energy density.

[0086] In the technical solution of this application embodiment, the battery cell 100 includes a housing, an electrode assembly 20 disposed in the housing, and a fixing member 30 disposed on the electrode assembly 20. The electrode assembly 20 is formed by winding multiple electrode sheets, and a tab 22 is provided at one end in the first direction X, and a first sub-component 31 in the fixing member 30 is provided. The first sub-component 31 is connected to two opposite surfaces of the electrode assembly 20 and can limit the thickness of the electrode assembly 20 by its own extension dimension in this direction. This can reduce the possibility that the wound electrode assembly 20 has an opening in the center, thereby reducing the possibility of the tab 22 folding or the separator folding, thereby reducing the risk of short circuit caused by the connection of the anode and cathode, and at the same time reducing the expansion of the electrode assembly 20 during operation, improving the reliability of the battery cell 100.

[0087] In some alternative embodiments, the electrode assembly 20 includes two tabs 22 spaced apart along a second direction Y, and a first sub-component 31 disposed between the two tabs 22, wherein the size of the first sub-component 31 in the second direction Y is less than or equal to the distance between the two tabs 22.

[0088] Optionally, the electrode assembly 20 may include an electrode body 21 and two tabs 22 connected to the electrode body 21. The two tabs 22 may both be located at the first end 211 and arranged at intervals along the second direction Y. A first sub-component 31 disposed at the first end 211 is located between the two tabs 22, so that the first sub-component 31 is disposed closer to the central region of the electrode body 21, which facilitates the application of a tightening and fixing force along the third direction Z.

[0089] Based on this, the size of the first sub-component 31 along the second direction Y can be less than or equal to the distance between the two tabs 22. Thus, the opposite two sides of the first sub-component 31 in the second direction Y can be respectively connected to the two tabs 22, or the size can be reduced to a certain extent relative to the edges of the two tabs 22 facing each other in the central area of ​​the second direction Y.

[0090] By limiting the length and position of the first sub-component 31, the possibility of interference between the first sub-component 31 and the tab 22 can be reduced, thereby improving the reliability of the battery cell 100, while ensuring that the first sub-component 31 is close to the center position of the electrode assembly 20 in the second direction Y and that the electrode body 21 is pressed tightly.

[0091] In some alternative embodiments, the difference between the dimension of the first sub-component 31 in the second direction Y and the distance between the two tabs 22 is 0-10 mm.

[0092] With the first sub-component 31 positioned between the two tabs 22, the difference between the dimension of the first sub-component 31 in the second direction Y and the distance between the tabs 22 can be selected as 0-10mm, for example, any one of 0, 2mm, 4mm, 6mm, 8mm, 10mm or any two of them.

[0093] By limiting the length of the first sub-component 31 in the second direction Y, the size of the first sub-component 31 can be adapted to the spacing of the tabs 22 of the electrode assembly 20. While maintaining the fixing and tightening force, a certain space margin is provided for the installation of the first sub-component 31, making it easy to assemble and less likely to interfere with the tabs 22.

[0094] In some optional embodiments, the fastener 30 further includes a second sub-component 32 disposed at the second end 212, the two ends of the second sub-component 32 being connected to the two opposing surfaces of the electrode body 21 in the third direction Z.

[0095] Similar to the first sub-component 31 disposed at the first end 211, the fastener 30 may also include a second sub-component 32 disposed at the second end 212, the second sub-component 32 being disposed opposite to the first sub-component 31 and being used to define the thickness dimension of the electrode assembly 20 at the second end 212 along the third direction Z.

[0096] Optionally, the second sub-component 32 may have the same or similar structural form as the first sub-component 31, with its opposite ends connected to the opposite two sides of the electrode assembly 20 in the third direction Z, and the electrode assembly 20 is correspondingly limited in the direction by its extension dimension or width dimension in the third direction Z, thereby pressing the first electrode group and the second electrode group together by tensioning or narrowing the second sub-component 32.

[0097] Optionally, the second sub-component 32 is disposed opposite to the first sub-component 31 in the first direction X. The first sub-component 31 and the second sub-component 32 can be symmetrically disposed about a reference plane, and the reference plane is perpendicular to the second direction Y. Furthermore, the two bending regions 214 in the electrode assembly 20 can be at the same vertical distance from the reference plane, thereby further ensuring that the electrode assembly 20 is subjected to uniform force.

[0098] By simultaneously providing fixing members 30 at both ends of the electrode assembly 20, the electrode assembly 20 can be subjected to uniform force and the possibility of an opening forming in the center of the electrode assembly 20 can be further reduced, thereby improving the reliability of the battery cell 100.

[0099] Please refer to the following: Figure 5 and Figure 6 , Figure 5 This is a top view schematic diagram of a partial structure of a battery cell 100 provided in some embodiments of this application. Figure 6 This is a bottom view of a partial structure of a battery cell 100 provided in some embodiments of this application.

[0100] In some optional embodiments, both the first sub-component 31 and the second sub-component 32 include a hollow area 311 and two connecting areas 312 located on both sides of the hollow area 311 along the third direction Z. The two connecting areas 312 are respectively connected to the two opposite side surfaces of the electrode body 21 in the third direction Z. The hollow area 311 is provided with a plurality of through holes that penetrate along the thickness direction of the fixing member 30.

[0101] Optionally, both the first sub-component 31 and the second sub-component 32 may include a hollow area 311 and a connecting area 312, and the connecting area 312 is disposed on opposite sides of the hollow area 311, so that the hollow area 311 with the through hole can be disposed directly opposite the end face of the electrode assembly 20 at the second end 212.

[0102] Taking the second sub-component 32 as an example, the second sub-component 32 may include two connecting areas 312 and a hollow area 311 sandwiched therebetween. The connecting areas 312 are used to connect with the surface of the electrode assembly 20, which may be an adhesive connection. The hollow area 311 can be tensioned through the connecting areas 312 and cover the end face of the electrode assembly 20 at the second end 212.

[0103] Optionally, when setting the second sub-component 32, the size of the hollow area 311 can be set according to the size of the end face of the second end 212 of the electrode assembly 20. For example, the length of the hollow area 311 in the second direction Y can be set according to the extension dimension of the area to be fixed in the second direction Y. Based on this, the shape of the second sub-component 32 after unfolding can be rectangular, that is, along the second direction Y, the extension dimension of the two connecting areas 312 can be the same as the extension dimension of the hollow area 311, so that the second sub-component 32 is easy to process. Alternatively, the extension dimension of the connecting area 312 in the second direction Y can be greater than or less than the extension dimension of the hollow area 311, as long as the connecting areas 312 on both sides of the hollow area 311 are symmetrically arranged, so that the second sub-component 32 is subjected to uniform force and the possibility of falling off or misalignment is reduced.

[0104] The hollow area 311 is provided with multiple through holes to allow gas and electrolyte to pass through the fixing member 30 and enter or exit the central region of the electrode assembly 20. The through holes provided in the hollow area 311 can be round holes, rectangular holes, elliptical holes or waist-shaped holes, etc., and can be arranged in an array and spaced apart to ensure uniform permeability of the fixing member in the hollow area 311 and facilitate processing.

[0105] By setting a hollow area 311 in the fixing member 30, a channel can be left for the passage of electrolyte and gas. While maintaining a large connection and fixing area, the electrode assembly 20 can achieve a good wetting effect and can discharge gas in time, thereby effectively improving the reliability of the battery cell 100.

[0106] In some optional embodiments, along the third direction Z, the size of the cutout area 311 is greater than or equal to the size of the electrode body 21, and along the first direction X, the orthographic projection of the connection area 312 of the first sub-component 31 forms a first pattern, and the orthographic projection of the connection area 312 of the second sub-component 32 forms a second pattern. The first pattern and the second pattern are both offset from and connected to the orthographic projection of the electrode body 21.

[0107] Optionally, in embodiments where both the first sub-component 31 and the second sub-component 32 are provided with a cutout area 311, the cutout area 311 of both can respectively cover the area where the two sub-components and the two end faces of the electrode assembly 20 are in contact with each other in the first direction X, that is, the area where the two sub-components and the two end faces of the electrode assembly 20 are in contact with each other in the first direction X is located within the cutout area 311.

[0108] Specifically, along the third direction Z, the extension dimension of the hollow area 311 can be the same as or slightly larger than the extension dimension of the electrode assembly 20 in the flat area 213. Furthermore, the connection area 312 of the first sub-component 31 and the second sub-component 32 can be connected only to the opposite two surfaces of the electrode assembly 20 in the third direction Z, without extending to the end face of the first end 211 and the second segment. That is, the orthographic projection of the connection area 312 along the first direction X is connected to the orthographic projection of the flat area 213 of the electrode assembly 20 along that direction but does not overlap.

[0109] Optionally, the hollow area 311 may have the same extension dimension as the flat area 213 in the third direction Z and make its opposite side edges in that direction flush with the opposite side edges of the corresponding end face of the electrode assembly 20; or, the hollow area 311 may extend from the end face of the electrode assembly 20 in the first direction X to at least one of the opposite side surfaces of the electrode assembly 20 in the third direction Z, as long as the connecting area 312 can securely connect the fastener 30 to the electrode assembly 20.

[0110] By making the hollow areas 311 in the two sub-components have a certain area and being positioned directly opposite the two end faces of the electrode assembly 20, the possibility of the fixing member 30 obstructing the flow of electrolyte or gas can be further reduced.

[0111] In some alternative embodiments, along the second direction Y, the size of the second sub-component 32 is less than or equal to the size of the straight area 213, and along the first direction X, the orthographic projection of the second sub-component 32 is offset from the orthographic projection of the bent area 214.

[0112] Optionally, in embodiments where a second sub-component 32 is provided, the second sub-component 32 can be entirely disposed within the flat region 213 and have an extension dimension in the second direction Y that is less than or equal to that of the flat region 213. Specifically, the maximum extension dimension of the second sub-component 32 in the second direction Y can be made smaller than the extension dimension of the flat region 213 at the end face of the second end 212 along that direction. Furthermore, the orthographic projection of the second sub-component 32 along the first direction X can be completely offset from the orthographic projection of the bending region 214 along that direction.

[0113] By positioning the second sub-component 32 in the flat area 213 and offsetting it from the bending area 214, the second sub-component 32 can be connected to the relatively flat, nearly planar, two-sided surfaces of the electrode assembly 20, thereby ensuring a firm connection between them. Simultaneously, offsetting the second sub-component 32 from the bending area 214 reduces the likelihood of warping or wrinkling after connection and facilitates easier connection of the second sub-component 32 to the electrode assembly 20.

[0114] In some optional embodiments, the difference between the size of the second sub-component 32 and the size of the straight area 213 along the second direction Y is 0-4 mm, and the minimum distance between the opposite side edges of the second sub-component 32 along the second direction Y and the opposite side edges of the straight area 213 in that direction is 0-2 mm.

[0115] Similar to the size setting of the first sub-component 31, the second sub-component 32 is set in the flat area 213, and the length dimension of the second sub-component 32 can be the same as or slightly smaller than the dimension of the flat area 213. Specifically, along the second direction Y, the difference between the two extension dimensions can be 0-4mm, for example, it can be any one of 0, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm or between any two of them.

[0116] Furthermore, the two opposite edges of the second sub-component 32 along the second direction Y have a first gap and a second gap with the one closer to the opposite two edges of the straight area 213 in the same direction. Both gaps can be between 0 and 2 mm, for example, any one of 0, 0.5 mm, 1 mm, 1.5 mm, 2 mm or between any two of them, so that the gap between the second sub-component 32 and the two edges of the straight area 213 is relatively uniform.

[0117] By limiting the difference between the length of the second sub-component 32 and the size of the flat area 213, the second sub-component 32 can have a length that matches the shape and size of the electrode assembly 20. While maintaining a good connection and fixing effect, a certain assembly tolerance is left, which makes it easy to connect the second sub-component 32 to the second end 212 of the electrode assembly 20.

[0118] In some optional embodiments, the fastener 30 is bonded to the electrode assembly 20. The fastener 30 includes an insulating carrier layer and a high-temperature resistant adhesive layer stacked together, with the high-temperature resistant adhesive layer located between the insulating carrier layer and the electrode assembly 20.

[0119] In this embodiment, the fastener 30 can be selected as high-temperature resistant adhesive tape and is connected and fixed to the electrode assembly 20 by adhesive bonding. Specifically, the fastener 30 can be selected as including an insulating support layer and a high-temperature resistant adhesive layer stacked together. The insulating support layer can be made of a high-temperature resistant flexible insulating material, so that the fastener 30 can be conformally positioned to the electrode assembly 20 while fixing the electrode assembly 20, reducing the possibility of damage to the electrode assembly 20. The high-temperature resistant adhesive layer can be made of an adhesive material that can maintain adhesion at high temperatures. During the operation of the battery cell 100, the electrode assembly 20 is prone to heat generation and expansion. By using a high-temperature resistant adhesive material to make the adhesive layer in the fastener 30, the possibility of problems such as the adhesive layer softening due to heat, the support layer falling off, or misalignment of the fastener 30 during the operation of the battery cell 100 can be reduced, thereby further improving the reliability of the battery cell 100.

[0120] In some alternative embodiments, the thickness of the fastener 30 is 0.05 μm to 0.2 μm.

[0121] Optionally, the extension dimension of the fastener 30 in its own thickness direction can be 0.05μm-0.2μm, for example, it can be any one of 0.05μm, 0.08μm, 0.11μm, 0.14μm, 0.17μm, 0.2μm or between any two of them, and can be further selected as about 0.1μm.

[0122] Optionally, the thickness of the fastener 30 can be the same or similar at various points to ensure uniform stress at the connection points with the electrode assembly 20. In embodiments where both the first sub-component 31 and the second sub-component 32 are provided, the thicknesses of the first sub-component 31 and the second sub-component 32 can be the same or similar to facilitate processing.

[0123] By limiting the numerical range of the thickness of the fastener 30, the fastener 30 can have a suitable thickness, thereby reducing the space required while maintaining good structural strength of the fastener 30, and reducing the possibility of interference with other components in the battery cell 100 or causing an increase in the size of the battery cell 100.

[0124] Secondly, according to the embodiments of this application, a battery device 200 is provided, including a housing 40 and a battery cell 100 as described in any embodiment of the first aspect, wherein the battery cell 100 is disposed in the housing 40.

[0125] Thirdly, according to the embodiments of this application, an electrical device is provided, including the battery device 200 in any embodiment of the second aspect, the battery device 200 being used to provide electrical energy.

[0126] The battery device 200 and the electrical equipment in this embodiment have all the beneficial effects of the battery cell 100 in the first aspect. For details, please refer to the specific description of the battery cell 100 in the above embodiments. This embodiment will not repeat the description here.

[0127] This application provides a battery cell 100, including a housing, an electrode assembly 20, and a fixing member 30. The electrode assembly 20 is disposed in the housing and includes a plurality of wound electrode sheets. The electrode assembly 20 includes an electrode body 21 and an electrode tab 22. The electrode body 21 has a first end 211 and a second end 212 disposed opposite to each other along a first direction X. The electrode tab 22 is connected to the first end 211. The electrode body 21 includes a flat region 213 and a bending region 214 located on both sides of the flat region 213 along a second direction Y. In the flat region 213, the electrode sheets are stacked along a third direction Z. The first direction X, the second direction Y, and the third direction Z are intersected in pairs. The fixing member 30 includes a first sub-component 31 disposed at the first end 211 and a second sub-component 32 disposed at the second end 212. The opposite ends of the first sub-component 31 and the second sub-component 32 are respectively connected to the opposite two side surfaces of the electrode body 21 in the third direction Z to limit the size of the electrode body 21 in the third direction Z.

[0128] The first sub-component 31 and the second sub-component 32 each include a hollow area 311 and two connecting areas 312 located on both sides of the hollow area 311 along the third direction Z. The two connecting areas 312 are respectively connected to the two opposite surfaces of the electrode body 21 in the third direction Z. The hollow area 311 is provided with a plurality of through holes that penetrate along the thickness direction of the fixing member 30.

[0129] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This 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 by, include: case; An electrode assembly is disposed in the housing and includes a plurality of wound electrode sheets. The electrode assembly includes an electrode body and electrode tabs. The electrode body has a first end and a second end disposed opposite to each other along a first direction. At least a portion of the electrode tabs are connected to the first end. The electrode body includes a flat region and a bent region located on both sides of the flat region along a second direction. In the flat region, the electrode sheets are stacked along a third direction. The first direction, the second direction, and the third direction intersect each other in pairs. The fastener includes a first sub-component disposed at the first end, wherein the two opposite ends of the first sub-component are respectively connected to the two opposite side surfaces of the electrode body in the third direction to define the size of the electrode body in the third direction.

2. The battery cell of claim 1, wherein, The electrode assembly includes two tabs spaced apart along the second direction, and a first sub-component is disposed between the two tabs. The size of the first sub-component in the second direction is less than or equal to the distance between the two tabs.

3. The battery cell of claim 2, wherein, The difference between the dimension of the first sub-component in the second direction and the distance between the two tabs is 0-10 mm.

4. The battery cell of any one of claims 1-3, wherein, The fixing member further includes a second sub-component disposed at the second end, wherein the two ends of the second sub-component are respectively connected to the two opposing surfaces of the electrode body on the third-direction side.

5. The battery cell of claim 4, wherein, Both the first sub-component and the second sub-component include a hollow area and two connecting areas located on both sides of the hollow area along the third direction. The two connecting areas are respectively connected to the opposite two side surfaces of the electrode body in the third direction. The hollow area is provided with a plurality of through holes that penetrate along the thickness direction of the fixing member.

6. The battery cell of claim 5, wherein, Along the third direction, the size of the hollow area is greater than or equal to the size of the electrode body. Along the first direction, the orthographic projection of the connection area of ​​the first sub-component forms a first pattern, and the orthographic projection of the connection area of ​​the second sub-component forms a second pattern. The first pattern and the second pattern are both offset from and connected to the orthographic projection of the electrode body.

7. The battery cell of claim 4, wherein, Along the second direction, the size of the second sub-component is less than or equal to the size of the straight area, and along the first direction, the orthographic projection of the second sub-component is offset from the orthographic projection of the bent area.

8. The battery cell of claim 7, wherein, Along the second direction, the difference between the size of the second sub-component and the size of the straight area is 0-4mm, and the minimum distance between the opposite two edges of the second sub-component along the second direction and the opposite two edges of the straight area in that direction is 0-2mm.

9. The battery cell of claim 1, wherein, The fastener is bonded to the electrode assembly. The fastener includes an insulating support layer and a high-temperature resistant adhesive layer stacked together. The high-temperature resistant adhesive layer is located between the insulating support layer and the electrode assembly.

10. The battery cell of claim 1, wherein, The thickness of the fastener is 0.05μm-0.2μm.

11. A battery device characterized by comprising: include: Box; A plurality of battery cells as described in any one of claims 1-10, wherein the battery cells are disposed in the housing.

12. An electrical device, characterized by Includes the battery device as described in claim 11, the battery device being used to provide electrical energy.

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