Battery monomer, battery device and electric equipment

Abstract

The utility model discloses a battery monomer, a battery device and electric equipment. The battery comprises a shell and an electrode assembly accommodated in the shell, and the electrode assembly comprises an insulating part, and a first pole piece and a second pole piece which are opposite in polarity. The first pole piece comprises a first pole piece main body and a first pole lug, the first pole lug is led out from the first pole piece main body along a first end surface in a first direction, and the first pole lug is provided with two first side surfaces which are oppositely arranged along a second direction; the insulating part is connected to the first pole piece and comprises an insulating body and a protruding part, at least part of the insulating body is arranged on the outer side of the first end face in the first direction, the protruding part protrudes out of the second end face of the insulating body in the first direction, and at least part of the protruding part is arranged on the outer side of the first side face in the second direction; and the first tab exceeds the protruding part in the direction far away from the first pole piece main body along the first direction. The protruding part is provided with two second side faces opposite in the second direction, and the second side faces are in smooth connection with the second end face.

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] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Summary of the Invention

[0004] This application provides a battery cell, a battery device, and an electrical appliance that improves reliability.

[0005] In a first aspect, this application provides a battery cell comprising a casing and an electrode assembly housed within the casing. The electrode assembly includes an insulating member and a first electrode and a second electrode with opposite polarities. The first electrode includes a first electrode body and a first tab. The first tab extends from a first end face of the first electrode body along a first direction. The first tab has two first side faces disposed opposite each other along a second direction. The first direction, the second direction, and the thickness direction of the first electrode are perpendicular to each other. The insulating member is connected to the first electrode and includes an insulating body and a protrusion. At least a portion of the insulating body is disposed on the outer side of the first end face along the first direction. The protrusion protrudes from a second end face of the insulating body in the first direction. At least a portion of the protrusion is disposed on the outer side of the first side face along the second direction. The first tab extends beyond the protrusion in the first direction away from the first electrode body. The protrusion has two second side faces opposite each other along the second direction, and the second side faces are smoothly connected to the second end face. The insulating body can block burrs on the first end face, and the protrusion can block burrs on the first side face, thus separating the burrs on the first end face and the first side face from the second electrode. This helps reduce the risk of burrs conducting between the positive and negative electrodes, reduces the possibility of thermal runaway caused by short circuits, and improves the reliability of the battery cell. The connection between the protrusion and the insulating body is relatively smooth and does not form a sharp structure, which helps reduce the risk of tearing of the insulating component at the connection between the protrusion and the insulating body, and improves the insulation protection effect of the insulating component.

[0006] In some embodiments, the projection of the second side surface is an arc along the thickness direction, and the projection of the second side surface is tangent to the projection of the second end surface. This helps to reduce the design difficulty of a smooth connection between the second side surface and the second end surface.

[0007] In some embodiments, the first side surface includes a straight portion and an arcuate portion, with the arcuate portion connecting the straight portion and the first end face along a first direction; at least a portion of the second side surface is located outside the arcuate portion along a second direction, and the second side surface has the same curvature as the arcuate portion. This reduces the likelihood that the outer side of the portion of the first side surface corresponding to the root of the first electrode tab will not have a protrusion, thus improving the insulation protection effect of the insulating member on the first side surface corresponding to the root of the first electrode tab.

[0008] In some embodiments, both the second side surface and the arcuate portion are arc surfaces. Along the thickness direction, the center of the circle corresponding to the projection of the second side surface coincides with the center of the circle corresponding to the projection of the arcuate portion. The first radius of the circle corresponding to the projection of the arcuate portion is r1, and the second radius of the circle corresponding to the projection of the second side surface is r2, where 0.1mm ≤ r1 - r2 ≤ 2mm. If r1 - r2 is greater than or equal to 0.1mm, the protrusion extending beyond the first electrode tab in the second direction is not too small, which helps the protrusion to more effectively block burrs on the first side surface. If r1 - r2 is less than or equal to 2mm, the protrusion extending beyond the first electrode tab in the second direction is not too large, which facilitates the bending of the first electrode tab and reduces the possibility of the end cap pressing against the protrusion and damaging the electrode assembly.

[0009] In some embodiments, the insulating body includes two insulating portions disposed opposite each other along the thickness direction; each insulating portion includes a first sub-portion and a second sub-portion. The first sub-portions of the two insulating portions are respectively disposed on both sides of the first electrode body along the thickness direction and connected to the first electrode body. The second sub-portions of the two insulating portions are disposed on the outer side of the first end face along a first direction and connected to each other, and the second sub-portions cover at least a portion of the first end face. On the one hand, the contact area between the insulating element and the first electrode can be increased by the two first sub-portions, reducing the risk of the insulating element falling off. On the other hand, the two second sub-portions can also cover the burrs on the first end face, thereby separating the burrs on the first end face from the second electrode in two directions along the thickness direction, which is beneficial to further reduce the risk of short circuit.

[0010] In some embodiments, the protrusion includes two sub-protrusions disposed opposite each other along the thickness direction. The two sub-protrusions are respectively connected to two insulating portions, and a portion of the first electrode tab is sandwiched between the two sub-protrusions. This allows the burrs on the first side surface to be separated from the second electrode sheet in two directions along the thickness direction, further reducing the risk of short circuits. Furthermore, the two sub-protrusions also provide protection for the root of the first electrode tab, reducing the risk of tearing at the root of the first electrode tab.

[0011] In some embodiments, the second sub-part has a third end face facing away from the first sub-part along a first direction. Along the thickness direction, the projections of the third end faces of the two second sub-parts overlap, and the second end face includes the third end faces of the two second sub-parts. The sub-protrusion has two opposing third side faces along a second direction. Along the thickness direction, the projections of the third side faces of the two sub-protrusions at least partially overlap, and the second side face includes the third side faces of the two sub-protrusions. The third side face of each sub-protrusion is smoothly connected to the third end face of the insulating part connected thereto. The edges of each insulating layer of the insulating member do not have sharp structures, and each insulating layer is not easily torn under external force, which is beneficial to improving the burr isolation effect of the insulating member on the first electrode sheet.

[0012] In some embodiments, the sub-protrusion includes a protruding body and two extensions. Along a second direction, the protruding body connects between the two extensions. The protruding body is located on one side of the first electrode tab along its thickness direction, and the two extensions are respectively located on both sides of the first electrode tab along the second direction. The extensions cover a portion of the second side surface. The protruding body can support the root of the first electrode tab near the first electrode body, reducing the risk of the first electrode tab being inserted backwards between the first and second electrodes during bending. Furthermore, the extensions can cover the burrs on the first side surface, separating the burrs from the second electrode, further reducing the risk of short circuits.

[0013] In some embodiments, the first electrode body includes a first current collector and a first film layer. The first current collector includes two first surfaces disposed opposite each other along the thickness direction, a first end face connecting the two first surfaces, and the first film layer disposed on the first surfaces. The first film layer and the first end face are spaced apart along a first direction, and a first sub-part covers a portion of the first surface and a portion of the first film layer along the thickness direction. This increases the connection area between the insulating body and the first electrode body, reducing the risk of insulation component detachment.

[0014] In some embodiments, the first film layer includes a main film region and a thinning region connected to the main film region. The thinning region is located on the side of the main film region near the first end face along a first direction, and the thickness of the thinning region is less than the thickness of the main film region. A first sub-part covers at least a portion of the thinning region along the thickness direction, and the projection of the first sub-part is separate from the projection of the main film region along the thickness direction. The first sub-part can share part of the space in the thickness direction with the main film region, which is beneficial to improving space utilization. There is no thickness overlap between the first sub-part and the main film region in the thickness direction, which can reduce the overall thickness of the first electrode and the insulating member at the edge, and help reduce the risk of poor gap control between the positive and negative electrodes due to edge bulging of the electrode assembly.

[0015] In some embodiments, the dimension of the portion of the first film layer covered by the first sub-part along the first direction is d1, where 0.1mm ≤ d1 ≤ 2mm. A d1 greater than or equal to 0.1mm increases the connection area between the insulating body and the first film layer, reducing the risk of insulation detachment; a d1 less than or equal to 2mm reduces the amount of insulation used, decreases the area of ​​the overlapping thickness between the insulation and the first film layer, which helps improve the curling phenomenon caused by uneven thickness, weakens the obstruction of active ions by the insulation, and reduces the capacity loss of the battery cell.

[0016] In some embodiments, the dimension of the second sub-part along the first direction is d2, where 0.1mm ≤ d2 ≤ 6mm. If d2 is greater than or equal to 0.1mm, the dimension of the insulating body extending beyond the first end face along the first direction is not too small, facilitating the second sub-part to cover the first end face along the first direction and improving the coverage effect on the burrs of the first end face; if d2 is less than or equal to 6mm, the dimension of the insulating body extending beyond the first end face along the first direction is not too large, and the dimension of the insulating part extending beyond the isolating part is not too large, which can reduce the pressing effect of the end cap on the electrode assembly and reduce the risk of the end cap damaging the electrode assembly.

[0017] In some embodiments, the thickness of the insulating part is h, where 9μm≤h≤30μm. h greater than or equal to 9μm reduces the risk of the insulating part being punctured by burrs, thus improving reliability; h less than or equal to 30μm reduces the weight of the insulating part, decreases the space occupied by the insulating part, and helps reduce the energy density loss of the battery cell.

[0018] In some embodiments, along the first direction, the distance between the third end face of the protrusion away from the insulating body and the first end face is d3, where 6mm ≤ d3 ≤ 15mm. If d3 is greater than or equal to 6mm, the protrusion can block more burrs on the first side and help reduce the risk of the first tab tearing at its root; if d3 is less than or equal to 15mm, the size of the first tab covered by the protrusion will not be too large, which can reduce the adverse effects of bending the first tab.

[0019] In some embodiments, the insulating element includes a substrate layer and an adhesive layer, with the substrate layer connected to the first electrode through the adhesive layer; the peel strength of the insulating element is 15 N / m-20 N / m. The relatively high peel strength between the insulating element and the first electrode helps reduce the risk of the insulating element detaching from the first electrode, thus improving reliability.

[0020] In some embodiments, the puncture strength of the insulation is greater than or equal to 410 gf. A higher puncture strength in the insulation helps reduce the risk of puncture and improves reliability.

[0021] In a second aspect, this application provides a battery device comprising a plurality of battery cells provided according to any embodiment of the first aspect.

[0022] Thirdly, this application provides an electrical device that includes a battery device according to any embodiment of the second aspect. Attached Figure Description

[0023] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0024] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0025] Figure 2 This is an exploded view of the battery device provided in some embodiments of this application;

[0026] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application;

[0027] Figure 4 This is a top view schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application;

[0028] Figure 5 for Figure 4 A partial sectional view along the AA direction;

[0029] Figure 6 A schematic diagram of the structure of the first electrode of a battery cell in a flattened state, provided in some embodiments of this application;

[0030] Figure 7 for Figure 6 Cross-sectional view along the CC direction;

[0031] Figure 8 for Figure 6 Cross-sectional view along the BB direction;

[0032] Figure 9 for Figure 6 A magnified view of region E in the middle;

[0033] Figure 10 for Figure 6 Cross-sectional view along the DD direction;

[0034] Figure 11 This is a schematic diagram of the structure of the insulating component of a battery cell provided in some embodiments of this application.

[0035] The reference numerals in the accompanying drawings for the specific embodiments are as follows:

[0036] Vehicle 1, battery unit 2, controller 3, motor 4, housing 5, first housing section 5a, second housing section 5b, storage space 5c, battery cell 6.

[0037] Electrode assembly 10, first electrode 11, first electrode body 111, first current collector body 1111, first surface 1111a, first film layer 1112, main film region 1112a, thinning region 1112b, first end face 111a, tab lead-out region 111b, non-tab lead-out region 111c, first tab 112, straight portion 1121, arc-shaped portion 1122, first side surface 112a, second electrode 12, second electrode body 121, second current collector body 1211, fourth end face 1211a, second film layer 1212, second tab 122. Isolator 13, Insulator 14, Insulating Body 141, First Sub-part 1411, Second Sub-part 1412, Third End Face 1412a, Second End Face 141a, Insulating Part 141b, Protrusion 142, Protruding Body 1421, Extension 1422, Third Side Face 1422a, Second Side Face 142a, Sub-protrusion 142b, Third End Face 142c, Recess 143, Insulating Layer 144, Substrate Layer 145, Adhesive Layer 146, Outer Shell 20, Housing 21, End Cap 22, Electrode Terminal 30, First Direction X, Second Direction Y, Thickness Direction Z. Detailed Implementation

[0038] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0039] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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 description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0040] In this application, the reference to "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 in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0041] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0042] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0043] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0044] In this application, "multiple" means two or more (including two).

[0045] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering.

[0046] In this embodiment of the application, the battery cell can be a secondary battery cell, which refers to a battery cell that can be used again after being discharged by recharging to activate the active materials.

[0047] 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-metal hydride battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., but the embodiments of this application are not limited to this.

[0048] A typical battery cell includes an electrode assembly, a housing, and electrode terminals. The electrode assembly is housed within the housing, and the electrode terminals are located within the housing. The housing encapsulates the electrode assembly and electrolyte components. The electrode assembly includes tabs, which are electrically connected to the electrode terminals via adapters or directly to the electrode terminals. The electrode terminals are used to electrically connect the electrode assembly to external circuitry within the battery cell to enable charging or discharging of the battery cell.

[0049] 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.

[0050] 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.

[0051] In some embodiments, the negative electrode may be a negative electrode sheet, which 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.

[0052] In some implementations, the separator is positioned 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] 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.

[0055] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0056] In some embodiments, the electrode assembly has a stacked structure.

[0057] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0058] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0059] A battery device typically includes a housing for encapsulating one or more individual battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the individual battery cells.

[0060] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into an independent module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties. The battery cell assembly can be housed within a housing by fixing the battery module within the housing. As an example, the housing can include a top cover, a frame, and a bottom plate. The top cover and bottom plate are respectively connected to the frame, creating a closed space inside the housing to house the battery cell assembly.

[0061] 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.

[0062] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0063] During the fabrication of electrodes (positive or negative electrodes), cutting (e.g., electrode slitting or tab die-cutting) is typically required to achieve the desired size and shape. The cut electrode usually consists of an electrode body and tabs extending from the end face of the electrode body. After cutting, burrs or metal particles are easily generated at the cut edges (e.g., the cut edges of the electrode body and the tabs). During the charging and discharging process of a battery cell, these burrs or metal particles may puncture the separator and conduct electricity between the positive and negative electrodes, posing a short-circuit risk and affecting the reliability of the battery cell.

[0064] To address the aforementioned issues, a feasible solution is to insulate and protect the cut edges of the electrode sheet using insulating tape. A portion of the insulating tape covers the cut end face of the electrode sheet body, while another portion covers the root area of ​​the tab, thus covering the burrs on the cut edges of both the electrode sheet body and the tab. At least a portion of the insulating tape covering the tab protrudes beyond the portion covering the electrode sheet body. During tape delivery, the connection between these two portions of the insulating tape is prone to tearing under external force, affecting the tape's protective effect on the electrode sheet.

[0065] In view of this, the present application provides a technical solution that connects an insulating member to a first electrode. The insulating member includes an insulating body and a protrusion. At least a portion of the insulating body is disposed on the outer side of the first end face of the first electrode body along a first direction to block burrs on the first end face. At least a portion of the protrusion is disposed on the outer side of the first side of the first electrode tab along a second direction to block burrs on the first side. This helps reduce the risk of burrs causing conduction between the positive and negative electrodes, improving the reliability of the battery cell. Furthermore, the two second sides of the protrusion along the second direction are smoothly connected to the second end face of the insulating body along the first direction. The connection between the protrusion and the insulating body is relatively smooth and does not form a sharp structure, which helps reduce the risk of tearing of the insulating member at the connection between the protrusion and the insulating body, improving the insulation protection effect of the insulating member.

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

[0067] The battery device disclosed in this application can be used in electrical devices that use the battery device as a power source or in various energy storage systems that use the battery device as an energy storage element. The electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc., and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0068] For ease of explanation, the following embodiments use a vehicle as an example of electrical equipment.

[0069] Figure 1 This is a structural schematic diagram of a vehicle provided in some embodiments of this application. (Refer to...) Figure 1 Vehicle 1 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 2 is installed inside vehicle 1, and the battery device 2 can be located at the bottom, front, or rear of vehicle 1. The battery device 2 can be used to power vehicle 1; for example, the battery device 2 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0070] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the 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 2This is an exploded structural diagram of a battery device provided in some embodiments of this application. (Refer to...) Figure 2 The battery device 2 includes a housing 5 and battery cells 6, with the battery cells 6 housed within the housing 5. The housing 5 provides space for the battery cells 6 and can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, together defining a housing space 5c for accommodating the battery cells 6. The second housing portion 5b may be a hollow structure with one open end, while the first housing portion 5a may be a plate-like structure, covering the open side of the second housing portion 5b so that the first housing portion 5a and the second housing portion 5b together define the housing space. Alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one open side, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b. Of course, the box 5 formed by the first box part 5a and the second box part 5b can be of various shapes, such as a cylinder, a cuboid, etc.

[0072] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

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

[0074] In the battery device 2, there can be multiple battery cells 6, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel configurations. Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 6 is housed within the housing 5. Alternatively, the battery device 2 can also consist of multiple battery cells 6 first connected in series, parallel, or in a mixed manner to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 5. The battery device 2 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 6.

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

[0076] Figure 3 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. (Refer to...) Figure 3 The battery cell 6 includes a housing 20 and an electrode assembly 10, with the electrode assembly 10 disposed inside the housing 20.

[0077] The outer casing 20 is used to encapsulate the electrode assembly 10 and electrolyte components. The outer casing 20 can be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0078] In some embodiments, the housing 20 is a hollow structure, with an internal space for accommodating 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 has a cuboid structure, a cuboid housing can be selected.

[0079] The outer casing 20 can be made of various materials, such as metal or plastic. Optionally, the outer casing 20 can be made of copper, iron, aluminum, steel, aluminum alloy, etc. For example, the outer casing 20 can be a steel casing, aluminum casing, plastic casing (such as polypropylene), composite metal casing (such as copper-aluminum composite casing), or aluminum-plastic film, etc.

[0080] As an example, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening and the end cap 22 for closing the opening.

[0081] The housing 21 is a component used to fit the end cap 22 to form the 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 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for 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 the material of the housing 21.

[0084] The end cap 22 can be connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0085] The housing 21 may be open at one end or open at both ends. For example, the housing 21 may be open on one side, with one end cap 22 covering the opening of the housing 21. Alternatively, the housing 21 may be open on both sides, with two end caps 22 covering the two openings of the housing 21 respectively.

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

[0087] Figure 4 This is a top view schematic diagram of the electrode assembly of a battery cell provided in some embodiments of this application. Figure 5 for Figure 4 A partial sectional view along the AA direction. (Refer to...) Figure 4 and Figure 5 The electrode assembly 10 includes a first electrode 11 and a second electrode 12 with opposite polarities.

[0088] For example, one of the first electrode 11 and the second electrode 12 is a positive electrode and the other is a negative electrode.

[0089] In some embodiments, the positive electrode may include a positive current collector and a positive electrode film layer disposed on at least one surface of the positive current collector. As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode film layer is disposed on either or both of the two opposite surfaces of the positive current collector.

[0090] As an example, the positive electrode current collector may be made of carbon, metal foil, or a composite current collector. The positive electrode film layer includes a positive electrode active material, which may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds.

[0091] In some embodiments, the negative electrode sheet may include a negative current collector and a negative electrode film layer disposed on at least one surface of the negative current collector. As an example, the negative current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode film layer is disposed on either or both of the two opposite surfaces of the negative current collector.

[0092] As an example, the negative electrode current collector can be a metal foil, a metal foam, or a composite current collector. The negative electrode film layer includes a negative electrode active material, which, as an example, can 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.

[0093] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0094] In some embodiments, the electrode assembly 10 further includes a separator 13 for separating the first electrode 11 and 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.

[0095] In some embodiments, the separator 13 includes a separator membrane. The separator membrane in this application can be any known porous structure separator membrane with good chemical and mechanical stability.

[0096] In some embodiments, the electrode assembly 10 is a wound structure. Exemplarily, the first electrode 11 and the second electrode 12 are both strip structures, and the first electrode 11, the spacer 13 and the second electrode 12 are wound into a wound structure.

[0097] In some embodiments, the electrode assembly 10 is a stacked structure. As an example, multiple first electrode plates 11 and multiple second electrode plates 12 may be provided, and multiple first electrode plates 11 and multiple second electrode plates 12 may be stacked alternately.

[0098] Reference Figures 1 to 9 In this embodiment of the application, the battery cell 6 includes a housing 20 and an electrode assembly 10 housed within the housing 20. The electrode assembly 10 includes an insulating member 14, and a first electrode 11 and a second electrode 12 with opposite polarities.

[0099] The first electrode 11 includes a first electrode body 111 and a first electrode tab 112. The first electrode tab 112 is led out from the first end face 111a of the first electrode body 111 along the first direction X. The first electrode tab 112 has two first side faces 112a arranged opposite each other along the second direction Y. The first direction X, the second direction Y and the thickness direction Z of the first electrode 11 are perpendicular to each other.

[0100] An insulating member 14 is connected to a first electrode 11. The insulating member 14 includes an insulating body 141 and a protrusion 142. At least a portion of the insulating body 141 is disposed on the outer side of a first end face 111a along a first direction X. The protrusion 142 protrudes from a second end face 141a of the insulating body 141 in the first direction X. At least a portion of the protrusion 142 is disposed on the outer side of a first side face 112a along a second direction Y. A first electrode tab 112 extends beyond the protrusion 142 along the first direction X in a direction away from the first electrode body 111. The protrusion 142 has two opposing second side faces 142a along the second direction Y, and the second side faces 142a are smoothly connected to the second end face 141a.

[0101] At least a portion of the first end face 111a and the first side face 112a may be formed in the cutting process of the first electrode 11.

[0102] The two first side surfaces 112a are arranged opposite each other along the second direction Y, meaning that the two first side surfaces 112a are arranged along the second direction Y, and the two first side surfaces 112a can be parallel to each other or not parallel.

[0103] Both the first electrode body 111 and the first electrode tab 112 have a small thickness. The first end face 111a and the first side face 112a have a small dimension in the thickness direction Z. Both the first end face 111a and the first side face 112a can be approximated as a line.

[0104] The insulating element 14 has a small thickness, and the second end face 141a and the second side face 142a have small dimensions in the thickness direction Z. Both the second end face 141a and the second side face 142a can be approximated as a line.

[0105] The statement that at least a portion of the insulating body 141 is located on the outer side of the first end face 111a along the first direction X means that at least a portion of the insulating body 141 protrudes from the first end face 111a in the first direction X, and does not require that the insulating body 141 and the first end face 111a overlap in the first direction X.

[0106] Optionally, the insulating body 141 overlaps with the first end face 111a in the first direction X. Along the thickness direction Z, the projection of the first end face 111a may lie within the projection of the insulating body 141.

[0107] The second end face 141a is an end face of the insulating body 141 that is away from the first electrode body 111 in the first direction X. The protrusion 142 protrudes from the second end face 141a along the direction from the first electrode body 111 to the first electrode tab 112.

[0108] The statement that at least a portion of the protrusion 142 is located on the outer side of the first side 112a along the second direction Y means that at least a portion of the protrusion 142 protrudes from the first side 112a along the second direction Y, and does not require that the protrusion 142 overlap with the first side 112a in the second direction Y.

[0109] Along the second direction Y, the two second side surfaces 142a of the protrusion 142 can be located outside the two first side surfaces 112a respectively.

[0110] The insulating element 14 can be connected to the first electrode 11 by adhesive, attachment or other suitable means.

[0111] The insulating component 14 can be connected to the first electrode body 111, or to the first electrode tab 112, or to both the first electrode body 111 and the first electrode tab 112.

[0112] The first electrode tab 112 extends beyond the protrusion 142 in the first direction X toward the direction away from the first electrode body 111. The portion of the first electrode tab 112 that extends beyond the protrusion 142 can be bent, which helps to reduce the stress on the first electrode tab 112 when bent.

[0113] The protrusion 142 can be formed by providing a recess 143 on the insulating member 14. The recess 143 can be formed by die-cutting off a portion of the insulating member 14.

[0114] The first electrode 11 may include a plurality of first electrode tabs 112. Correspondingly, the insulating member 14 includes a plurality of protrusions 142, and the plurality of protrusions 142 are disposed in a one-to-one correspondence with the plurality of first electrode tabs 112. A recess 143 is formed between any two adjacent protrusions 142.

[0115] The electrode assembly 10 and the end cap 22 are arranged along the first direction X. The recess 143 can reduce the size of the insulating body 141 extending beyond the insulating member 13 along the first direction X, thereby reducing the pressing effect of the end cap 22 on the electrode assembly 10 and reducing the risk of the electrode assembly 10 being damaged by the end cap 22.

[0116] The second side surface 142a may be entirely curved, or only a portion of the second side surface 142a may be curved. Optionally, at least the portion of the second side surface 142a that is directly connected to the second end face 141a may be curved to ensure a smooth connection with the second end face 141a.

[0117] The smooth connection between the second side surface 142a and the second end surface 141a means that the connection position between the second side surface 142a and the second end surface 141a is relatively smooth, without forming sharp structures such as acute angles, right angles or obtuse angles, and the transition between the second side surface 142a and the second end surface 141a is relatively gentle.

[0118] The insulating component 14 can be a one-piece molded structure or it can be assembled or connected together from multiple parts.

[0119] At least a portion of the insulating body 141 is disposed on the outer side of the first end face 111a of the first electrode body 111 along the first direction X, which can block burrs on the first end face 111a. At least a portion of the protrusion 142 is disposed on the outer side of the first side surface 112a of the first electrode tab 112 along the second direction Y, which can block burrs on the first side surface 112a. This separates the burrs on the first end face 111a and the first side surface 112a from the second electrode 12, which helps to reduce the risk of burrs conducting between the positive and negative electrodes, reduces the possibility of thermal runaway caused by short circuit, and improves the reliability of the battery cell 6. For example, the insulating member 14 can separate the burrs from the separator 13, reducing the risk of burrs piercing the separator 13.

[0120] Furthermore, the connection between the protrusion 142 and the insulating body 141 is relatively smooth and will not form a sharp structure, which helps to reduce the risk of the insulating component 14 tearing at the connection between the protrusion 142 and the insulating body 141 and improves the insulation protection effect of the insulating component 14.

[0121] In some embodiments, along the thickness direction Z, the projection of the second side surface 142a is an arc shape, and the projection of the second side surface 142a is tangent to the projection of the second end surface 141a.

[0122] Along the thickness direction Z, the projection of the second end face 141a can be a straight line or an arc curve.

[0123] Optionally, the projection of the second end face 141a along the thickness direction Z is one or more straight lines.

[0124] The protrusion 142 has a relatively small dimension along the first direction X. In this embodiment, the second side surface 142a is set as an arc surface, which helps to reduce the design difficulty of a smooth connection between the second side surface 142a and the second end surface 141a. For example, the protrusion 142 can be formed by die-cutting off a portion of the insulating member 14. The projection of the second side surface 142a is arc-shaped, which helps to reduce the difficulty of die-cutting.

[0125] In some embodiments, the first side surface 112a includes a straight portion 1121 and an arcuate portion 1122, with the arcuate portion 1122 connecting the straight portion 1121 and the first end face 111a along a first direction X. At least a portion of the second side surface 142a is located outside the arcuate portion 1122 along a second direction Y, and the second side surface 142a has the same curvature as the arcuate portion 1122.

[0126] The straight section 1121 is a plane, and the projection of the straight section 1121 along the thickness direction Z is a straight line.

[0127] The arc-shaped part 1122 is an arc-shaped curved surface, and the projection of the arc-shaped part 1122 along the thickness direction Z is an arc-shaped curve.

[0128] The second side surface 142a may be entirely located on the outer side of the arcuate portion 1122 along the second direction Y, or only a part of the second side surface 142a may be located on the outer side of the arcuate portion 1122 along the second direction Y. The other part of the second side surface 142a may be located, for example, on the outer side of the straight portion 1121 along the second direction Y.

[0129] Having the same curvature trend as the arcuate portion 1122 means that the general curvature trend of the second side surface 142a is the same as that of the arcuate portion 1122, but it does not require that the curvature shape of the second side surface 142a be the same as that of the arcuate portion 1122. For example, the curvature of the second side surface 142a may be the same as or different from that of the arcuate portion 1122.

[0130] The second side 142a of the protrusion 142 has the same curvature as the arcuate portion 1122 of the first tab 112, which can reduce the possibility that the outer side of the first side 112a corresponding to the root of the first tab 112 does not have the protrusion 142, and is conducive to improving the insulation protection effect of the insulating member 14 on the first side 112a corresponding to the root of the first tab 112.

[0131] In some embodiments, both the second side surface 142a and the arcuate portion 1122 are arc surfaces. Along the thickness direction Z, the center of the circle corresponding to the projection of the second side surface 142a coincides with the center of the circle corresponding to the projection of the arcuate portion 1122. The first radius of the circle corresponding to the projection of the arcuate portion 1122 is r1, and the second radius of the circle corresponding to the projection of the second side surface 142a is r2, where 0.1mm ≤ r1 - r2 ≤ 2mm.

[0132] Optionally, the central angle corresponding to the projection of the second side 142a may be the same as the central angle corresponding to the projection of the arc-shaped portion 1122.

[0133] Optionally, r1-r2 can be 0.1mm, 0.3mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, or any value between any two of them.

[0134] The radius of the circle corresponding to the projection of the arc-shaped portion 1122 is greater than the radius of the circle corresponding to the projection of the second side surface 142a. The difference between the radius of the circle corresponding to the projection of the arc-shaped portion 1122 and the radius of the circle corresponding to the projection of the second side surface 142a can represent the size by which the protrusion 142 extends beyond the first tab 112 along the second direction Y.

[0135] The projections of the second side surface 142a and the arcuate portion 1122 along the thickness direction Z are concentric arcs. On the one hand, the first tab 112 and the protrusion 142 can be die-cut using the same die-cutting mechanism, which helps to simplify the production equipment structure of the battery cell 6 and reduce costs; on the other hand, the protrusion 142 extends relatively uniformly beyond the first tab 112 along the second direction Y, which helps to improve the blocking effect of the insulating member 14 on the burrs of the first side surface 112a.

[0136] In this embodiment, r1-r2 is set to be greater than or equal to 0.1 mm, and the protrusion 142 extends beyond the first tab 112 in the second direction Y by a size that is not too small, which helps the protrusion 142 to more effectively block burrs on the first side 112a. In this embodiment, r1-r2 is set to be less than or equal to 2 mm, and the protrusion 142 extends beyond the first tab 112 in the second direction Y by a size that is not too large, which helps to bend the first tab 112 and reduces the possibility that the end cap 22 may press against the protrusion 142 and damage the electrode assembly 10.

[0137] In some embodiments, the insulating body 141 includes two insulating portions 141b disposed opposite to each other along the thickness direction Z. Each insulating portion 141b includes a first sub-portion 1411 and a second sub-portion 1412. The first sub-portions 1411 of the two insulating portions 141b are respectively disposed on both sides of the first electrode body 111 along the thickness direction Z and connected to the first electrode body 111. The second sub-portions 1412 of the two insulating portions 141b are disposed on the outer side of the first end face 111a along the first direction X and connected to each other. The second sub-portions 1412 cover at least a portion of the first end face 111a.

[0138] Along the thickness direction Z, the projection of the first sub-part 1411 is located within the projection of the first electrode body 111, and the projection of the second sub-part 1412 does not overlap with the projection of the first electrode body 111.

[0139] The first sub-parts 1411 of the two insulating portions 141b may have the same or different shapes. Along the thickness direction Z, the projections of the first sub-parts 1411 of the two insulating portions 141b at least partially overlap.

[0140] Along the direction from the first electrode body 111 to the first electrode tab 112, the second sub-part 1412 protrudes from the first end face 111a.

[0141] The second sub-parts 1412 of the two insulating portions 141b may have the same or different shapes. Along the thickness direction Z, the projections of the second sub-parts 1412 of the two insulating portions 141b at least partially overlap.

[0142] The second sub-parts 1412 of the two insulating parts 141b can be connected by adhesive or other suitable means.

[0143] The second sub-part 1412 covering at least a portion of the first end face 111a means that, along the first direction X, the projection of the second sub-part 1412 at least partially overlaps with the projection of the first end face 111a, and the second sub-part 1412 is able to cover at least a portion of the first end face 111a along the first direction X.

[0144] The first end face 111a may include a tab lead-out area 111b and a non-tab lead-out area 111c, wherein the first tab 112 is led out only from the tab lead-out area 111b and not from the non-tab lead-out area 111c. Optionally, along the first direction X, the second sub-parts 1412 of the two insulating portions 141b may cover the non-tab lead-out area 111c.

[0145] In this embodiment of the application, by providing two insulating portions 141b, on the one hand, the contact area between the insulating member 14 and the first electrode 11 can be increased by the two first sub-parts 1411, reducing the risk of the insulating member 14 falling off. On the other hand, the burrs of the first end face 111a can be covered by the two second sub-parts 1412, thereby separating the burrs of the first end face 111a from the second electrode 12 in two directions along the thickness direction Z, which is beneficial to further reduce the risk of short circuit.

[0146] In some embodiments, the protrusion 142 includes two sub-protrusions 142b disposed opposite to each other along the thickness direction Z, the two sub-protrusions 142b being respectively connected to two insulating portions 141b, and a portion of the first electrode tab 112 being sandwiched between the two sub-protrusions 142b.

[0147] The insulating member 14 includes two insulating layers 144, which are disposed opposite each other along the thickness direction Z. Each insulating layer 144 may include a sub-protrusion 142b and an insulating portion 141b connected to the sub-protrusion 142b. Optionally, the two insulating layers 144 may be formed independently.

[0148] The two sub-protrusions 142b can be integrally formed with the two insulating portions 141b respectively. Optionally, the insulating portion 141b and the sub-protrusions 142b located on the same side along the thickness direction Z can be integrally formed.

[0149] The two sub-protrusions 142b can have the same or different shapes.

[0150] Along the thickness direction Z, the projections of the two sub-protrusions 142b at least partially overlap. The two sub-protrusions 142b can be connected to each other by adhesive bonding or other suitable directions.

[0151] The root region where the first electrode tab 112 is directly connected to the first electrode body 111 can be sandwiched between the two sub-protrusions 142b.

[0152] A portion of the sub-protrusion 142b is located on one side of the first electrode tab 112 along the thickness direction Z, and covers the root region of the first electrode tab 112 along the thickness direction Z; another portion of the sub-protrusion 142b is located on the outer side of the first electrode tab 112 along the second direction Y, that is, the first side surface 112a of the first electrode tab 112 extends beyond the first electrode tab 112 in the second direction Y. The portions of the two sub-protrusions 142b that extend beyond the first electrode tab 112 can be connected to each other.

[0153] In this embodiment, by providing two sub-protrusions 142b, the burrs on the first side surface 112a can be separated from the second electrode plate 12 in two directions along the thickness direction Z, which helps to further reduce the risk of short circuit. Furthermore, the two sub-protrusions 142b can also protect the root of the first electrode tab 112, reducing the risk of tearing at the root of the first electrode tab 112.

[0154] In some embodiments, the second sub-part 1412 has a third end face 1412a facing away from the first sub-part 1411 along a first direction X. Along the thickness direction Z, the projections of the third end faces 1412a of the two second sub-parts 1412 overlap, and the second end face 141a includes the third end faces 1412a of the two second sub-parts 1412. The sub-protrusion 142b has two opposing third side faces 1422a along a second direction Y. Along the thickness direction Z, the projections of the third side faces 1422a of the two sub-protrusions 142b at least partially overlap, and the second side face 142a includes the third side faces 1422a of the two sub-protrusions 142b. The third side face 1422a of each sub-protrusion 142b is smoothly connected to the third end face 1412a of the insulating portion 141b connected thereto.

[0155] The third end face 1412a of the second sub-part 1412 can be formed by a die-cutting process. Optionally, the third end faces 1412a of the two second sub-parts 1412 can be die-cut in one die-cutting process so that their projections along the thickness direction Z overlap. Alternatively, the third end faces 1412a of the two second sub-parts 1412 can also be formed in different die-cutting processes.

[0156] Along the first direction X, the third side surface 1422a of the two sub-protrusions 142b are flush with each other.

[0157] The third side surface 1422a of the sub-protrusion 142b can be formed by a die-cutting process. Optionally, the third side surface 1422a of the two sub-protrusions 142b can be die-cut in one die-cutting process, such that their projections along the thickness direction Z at least partially overlap.

[0158] The third side surface 1422a of the two sub-protrusions 142b can be flush with each other along the first direction X. The third side surface 1422a of one of the sub-protrusions 142b can also extend beyond the third side surface 1422a of the other sub-protrusion 142b along the first direction X.

[0159] The third side 1422a of the two sub-protrusions 142b can be flush with each other along the second direction Y.

[0160] The third side surface 1422a of each sub-protrusion 142b is smoothly connected to the third end surface 1412a of the insulating part 141b connected thereto. As a result, the edges of each insulating layer 144 of the insulating member 14 do not have sharp structures, and each insulating layer 144 is not easily torn under external force, which is beneficial to improving the burr isolation effect of the insulating member 14 on the first electrode 11.

[0161] In some embodiments, the sub-protrusion 142b includes a protruding body 1421 and two extensions 1422. Along the second direction Y, the protruding body 1421 is connected between the two extensions 1422. The protruding body 1421 is located on one side of the first tab 112 along the thickness direction Z, and the two extensions 1422 are respectively located on both sides of the first tab 112 along the second direction Y. The extensions 1422 cover a portion of the second side surface 142a.

[0162] Along the thickness direction Z, the projection of the protruding body 1421 is located within the projection of the first tab 112, and the projection of the extension 1422 does not overlap with the projection of the first tab 112.

[0163] Optionally, along the thickness direction Z, the projections of the extensions 1422 of the two sub-protrusions 142b at least partially overlap and are connected to each other by adhesive or other suitable means.

[0164] The protruding body 1421 can be connected to the first tab 112 by adhesive or other suitable means.

[0165] Two extensions 1422 are located on the outer sides of the two first side surfaces 112a of the first tab 112 along the second direction Y. The two extensions 1422 may have the same shape or different shape.

[0166] The extension 1422 covering a portion of the second side surface 142a means that, along the second direction Y, the projection of the extension 1422 partially overlaps with the projection of the second side surface 142a, and the extension 1422 is able to cover a portion of the second side surface 142a along the second direction Y. Optionally, the extension 1422 may cover the second side surface 142a corresponding to the root region of the first tab 112.

[0167] In this embodiment, the protruding body 1421 supports the first tab 112 near the root of the first electrode body 111, reducing the risk of the first tab 112 being inserted backwards between the first electrode 11 and the second electrode 12 during bending. The extension 1422 in this embodiment helps to cover the burrs on the first side surface 112a, separating the burrs from the second electrode 12 and further reducing the risk of short circuits.

[0168] In some embodiments, the first electrode body 111 includes a first current collector 1111 and a first film layer 1112. The first current collector 1111 includes two first surfaces 1111a disposed opposite each other along the thickness direction Z, a first end face 111a connecting the two first surfaces 1111a, and the first film layer 1112 disposed on the first surface 1111a. The first film layer 1112 and the first end face 111a are spaced apart along the first direction X, and a first sub-part 1411 covers a portion of the first surface 1111a and a portion of the first film layer 1112 along the thickness direction Z.

[0169] In some examples, the first electrode 11 is a positive electrode, the positive current collector may include a first current collector body 1111, and the first film layer 1112 includes a positive active material layer. In other examples, the first electrode 11 is a negative electrode, the negative current collector may include a first current collector body 1111, and the first film layer 1112 includes a negative active material layer.

[0170] Optionally, a first film layer 1112 may be provided on one first surface 1111a, or both second surfaces 1111a may be provided with the first film layer 1112.

[0171] The first membrane layer 1112 and the first end face 111a are spaced apart along the first direction X, meaning that the first membrane layer 1112 only covers a part of the first surface 1111a, and the other part of the first surface 1111a is not covered by the first membrane layer 1112, and the area of ​​the first current collector 1111 that is not covered by the first membrane layer 1112 forms a blank area.

[0172] The first sub-part 1411 covers a portion of the first surface 1111a along the thickness direction Z, and the portion of the first sub-part 1411 covering the first surface 1111a can be connected to the first current collector 1111. The first sub-part 1411 also covers a portion of the first membrane layer 1112 along the thickness direction Z, and the portion of the first sub-part 1411 covering the first membrane layer 1112 can be connected to the first membrane layer 1112.

[0173] The first sub-part 1411 of this application embodiment simultaneously covers a portion of the first surface 1111a and a portion of the first film layer 1112, which is beneficial to increase the connection area between the insulating body 141 and the first electrode body 111 and reduce the risk of the insulating component 14 falling off.

[0174] In some embodiments, the first film layer 1112 includes a main film region 1112a and a thinning region 1112b connected to the main film region 1112a. The thinning region 1112b is located on the side of the main film region 1112a near the first end face 111a along the first direction X, and the thickness of the thinning region 1112b is less than the thickness of the main film region 1112a. A first sub-part 1411 covers at least a portion of the thinning region 1112b along the thickness direction Z, and the projection of the first sub-part 1411 is opposite to the projection of the main film region 1112a along the thickness direction Z.

[0175] The main membrane region 1112a can be of uniform thickness, and the average thickness of the thinning region 1112b is less than the thickness of the main membrane region 1112a.

[0176] The thinning region 1112b is closer to the first end face 111a than the main film region 1112a. Optionally, the thickness of the thinning region 1112b gradually decreases along the direction from the first electrode body 111 to the first tab 112. The gradual change in thickness of the thinning region 1112b reduces the possibility of steps forming in the first film layer 1112, which helps to reduce stress concentration.

[0177] Optionally, along the thickness direction Z, the first sub-section 1411 does not extend beyond the main membrane region 1112a.

[0178] Along the thickness direction Z, the projection of the first sub-part 1411 at least partially overlaps with the projection of the thinning region 1112b. The first sub-part 1411 can share part of the space in the thickness direction Z with the main film region 1112a, which is beneficial to improving space utilization. In the first direction X, the first sub-part 1411 and the main film region 1112a are spaced apart, and the first sub-part 1411 and the main film region 1112a do not overlap in the thickness direction Z, so there is no thickness superposition. This can reduce the thickness of the whole formed by the first electrode 11 and the insulating member 14 at the edge, which is beneficial to reducing the risk of poor gap control between the positive and negative electrodes due to edge bulging of the electrode assembly 10.

[0179] Furthermore, the first sub-section 1411 does not obstruct the transport of ions between the main film region 1112a and the second electrode 12, which helps to reduce the capacity loss of the battery cell 6.

[0180] In some embodiments, the portion of the first film layer 1112 covered by the first sub-part 1411 has a dimension d1 along the first direction X, where 0.1mm≤d1≤2mm.

[0181] Optionally, d1 can be 0.1mm, 0.3mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.2mm, 1.4mm, 1.6mm, 1.8mm, 2.0mm, or any value between any two of these.

[0182] In this embodiment, setting d1 to be greater than or equal to 0.1 mm increases the connection area between the insulating body 141 and the first film layer 1112, reducing the risk of the insulating component 14 detaching. In this embodiment, setting d1 to be less than or equal to 2 mm reduces the amount of insulating component 14 used, decreases the area of ​​the overlapping thickness between the insulating component 14 and the first film layer 1112, which helps improve the curling phenomenon caused by uneven thickness, weakens the obstruction of active ions by the insulating component 14, and reduces the capacity loss of the battery cell 6.

[0183] In some embodiments, the dimension of the second sub-part 1412 along the first direction X is d2, where 0.1mm≤d2≤6mm.

[0184] Optionally, d2 can be 0.1mm, 0.3mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, or any value between two of these.

[0185] The dimension of the second sub-part 1412 along the first direction X is the dimension of the insulating body 141 extending beyond the first end face 111a along the first direction X.

[0186] In this embodiment, d2 is set to be greater than or equal to 0.1 mm, ensuring that the dimension of the insulating body 141 extending beyond the first end face 111a along the first direction X is not too small. This facilitates the second sub-part 1412 covering the first end face 111a along the first direction X, improving the coverage effect on the burrs of the first end face 111a. In this embodiment, d2 is set to be less than or equal to 6 mm, ensuring that the dimension of the insulating body 141 extending beyond the first end face 111a along the first direction X is not too large, and that the dimension of the insulating member 14 extending beyond the isolating member 13 is not too large. This reduces the pressing effect of the end cap 22 on the electrode assembly 10, lowering the risk of the end cap 22 damaging the electrode assembly 10.

[0187] In some embodiments, the thickness of the insulating portion 141b is h, where 9 μm ≤ h ≤ 30 μm.

[0188] Optionally, h can be 9μm, 10μm, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 24μm, 26μm, 28μm, 30μm or any value between two of these.

[0189] The thickness of the protrusion 142b and the thickness of the insulating portion 141b can be the same or different. Optionally, the insulating layer 144 of the insulating member 14 can be a structure of equal thickness.

[0190] In this embodiment, setting h to be greater than or equal to 9 μm reduces the risk of the insulating component 14 being punctured by burrs, which is beneficial to improving reliability. In this embodiment, setting h to be less than or equal to 30 μm reduces the weight of the insulating component 14 and the space occupied by the insulating component 14, which is beneficial to reducing the energy density loss of the battery cell 6.

[0191] In some embodiments, along the first direction X, the distance between the third end face 142c of the protrusion 142 away from the insulating body 141 and the first end face 111a is d3, 6mm≤d3≤15mm.

[0192] Optionally, d3 can be 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm or any value between any two of these.

[0193] The distance between the third end face 142c and the first end face 111a is the size of the protrusion 142 extending beyond the first end face 111a along the first direction X, that is, the size of the portion of the first tab 112 covered by the protrusion 142 along the first direction X.

[0194] In this embodiment, d3 is set to be greater than or equal to 6 mm. The protrusion 142 can block more burrs on the first side 112a and helps reduce the risk of the first tab 112 tearing at its root. In this embodiment, d3 is set to be less than or equal to 15 mm. The size of the first tab 112 covered by the protrusion 142 is not too large, which can reduce the adverse effects of bending the first tab 112.

[0195] In some embodiments, the insulating member 14 includes a substrate layer 145 and an adhesive layer 146, wherein the substrate layer 145 is connected to the first electrode 11 via the adhesive layer 146. The peel strength between the insulating member 14 and the first electrode 11 is 15 N / m to 20 N / m.

[0196] Optionally, the substrate layer 145 may include at least one of polyethylene terephthalate, polypropylene, polyethylene, and their block copolymers.

[0197] Optionally, the adhesive layer 146 may include at least one of polyolefin, polyester, and styrene-isobutylene copolymer.

[0198] Optionally, the insulating element 14 includes two insulating layers 144, each insulating layer 144 including a substrate layer 145 and an adhesive layer 146. The adhesive layers 146 of the two insulating layers 144 are bonded together.

[0199] The substrate layer 145 can improve the strength of the insulating component 14 and reduce the deformation of the insulating component 14 during the attachment process. The insulating component 14 can be bonded to the first electrode 11 through the adhesive layer 146, which helps to improve the connection strength and stability between the insulating component 14 and the first electrode 11 and reduces the risk of the insulating component 14 falling off.

[0200] Optionally, the peel strength of the insulating element 14 and the first electrode 11 can be 15 N / m, 16 N / m, 17 N / m, 18 N / m, 19 N / m, 20 N / m or any value between any two of them.

[0201] Optionally, the insulating component 14 may include two insulating layers 144. The peel strength between the insulating component 14 and the first electrode 11 can be measured as follows: An insulating layer 144 with a thickness of 13 μm and a width of 8 mm is adhered to an aluminum foil with a thickness of 13 μm. The sample is immersed in an electrolyte at 70°C for 200 h, 400 h, 600 h, 800 h, and 1000 h, respectively, and then its peel strength is tested. Using a high-speed rail tensile testing machine, the sample after immersion is adhered to a stainless steel plate with double-sided tape, the side with the insulating layer 144 facing outwards, and is pressed firmly with a pressure roller. The entire sample is fixed on the tensile testing machine. The tensile testing machine clamps one end of the insulating layer 144 and pulls it upwards at a speed of 50 mm / min until the insulating layer 144 is completely peeled off from the aluminum foil. The displacement and force during the process are recorded. The results show that after 1000 h, the insulating layer 144 did not detach, and the peel strength is greater than 19 N / m.

[0202] The relatively high peel strength of the insulating component 14 and the first electrode 11 helps to reduce the risk of the insulating component 14 falling off the first electrode 11 and improves reliability.

[0203] In some embodiments, the puncture strength of the insulating element 14 is greater than or equal to 410 gf.

[0204] The puncture strength of the insulating component 14 can be determined according to standard GB / T36363-2018.

[0205] Optionally, the insulating element 14 may include two insulating layers 144. The insulating layer 144 with a thickness of 13μm and a size of 50mm×50mm is used for testing. A steel needle with a diameter of 1mm is used to test on a puncture tester. The force when the insulating layer 144 is punctured at a speed of 50mm / min is recorded. The recorded results are shown in Table 1.

[0206] Table 1

[0207] Needle puncture intensity (gf) 416.33 414.29 428.57 423.47 420.41 430.61 414.29 433.67 426.53 444.90 Mean = 425.31

[0208] As can be seen from Table 1, the insulating component 14 has a high puncture strength, which helps to reduce the risk of the insulating component 14 being punctured and improves reliability.

[0209] In some embodiments, the insulating element 14 has good insulation properties, the insulating element 14 will not break down under a voltage of 200V, and the resistance of the insulating element 14 is greater than or equal to 9999 megohms.

[0210] In some embodiments, the insulating element 14 exhibits good electrochemical stability. The withstand voltage test method for the insulating element 14 is as follows.

[0211] Conductive carbon black and hot melt adhesive were mixed in a mass ratio of 7:3, and then N-methylpyrrolidone solvent was added to disperse the mixture evenly to obtain a slurry. The solid content of the slurry was controlled at 7-10%. The slurry was coated onto aluminum foil and dried to obtain an electrode. The prepared electrode was fabricated into a button cell in a glove box for cyclic voltammetry testing. The test conditions were as follows: a scan speed of 0.1 mV / s was used for 3 cycles to observe whether redox peaks appeared within the voltage range of 2.5-5V. The voltage at which the first oxidation peak appeared was recorded to determine the electrochemical stability of the material. The test results are shown in Table 2.

[0212] Table 2

[0213] sample Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Oxidation voltage (V) 4.6 4.7 4.5 4.6 4.7

[0214] As can be seen from Table 2, the insulating component 14 exhibits an oxidation peak at higher voltages, demonstrating good electrochemical stability.

[0215] In some embodiments, the second electrode 12 includes a second electrode body 121 and a second tab 122, with the second electrode body 121 stacked on top of the first electrode body 111. The second electrode body 121 includes a second current collector 1211 and a second film layer 1212. The second current collector 1211 has a fourth end face 1211a on one side along the first direction X, and the second film layer 1212 is disposed on the surface of the second current collector 1211 along the thickness direction Z. In the thickness direction Z, the insulating member 14 separates the fourth end face 1211a from the first electrode 11.

[0216] According to a second aspect of this application, embodiments of this application also provide a battery device 2, which includes a plurality of battery cells 6 provided according to any embodiment of the first aspect of this application.

[0217] According to a third aspect of this application, embodiments of this application also provide an electrical device, which includes a battery device provided according to any embodiment of the second aspect of this application. The electrical device may be any of the aforementioned devices or systems that utilize individual battery cells.

[0218] This 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 an insulator 14, and a first electrode 11 and a second electrode 12 with opposite polarities. The first electrode 11 includes a first electrode body 111 and a first tab 112. The first tab 112 extends from a first end face 111a of the first electrode body 111 along a first direction X. The first tab 112 has two first side faces 112a disposed opposite each other along a second direction Y. The first direction X, the second direction Y, and the thickness direction Z of the first electrode 11 are perpendicular to each other.

[0219] An insulating member 14 is connected to a first electrode 11. The insulating member 14 includes an insulating body 141 and a protrusion 142. At least a portion of the insulating body 141 is disposed on the outer side of a first end face 111a along a first direction X. The protrusion 142 protrudes from a second end face 141a of the insulating body 141 in the first direction X. At least a portion of the protrusion 142 is disposed on the outer side of a first side face 112a along a second direction Y. The first electrode tab 112 extends beyond the protrusion 142 along the first direction X in a direction away from the first electrode body 111. The protrusion 142 has two opposing second side faces 142a along the second direction Y. Along the thickness direction Z, the projection of the second side face 142a is arc-shaped, and the projection of the second side face 142a is tangent to the projection of the second end face 141a.

[0220] The first side surface 112a includes a straight portion 1121 and an arcuate portion 1122. Along the first direction X, the arcuate portion 1122 connects the straight portion 1121 and the first end face 111a. At least a portion of the second side surface 142a is located outside the arcuate portion 1122 along the second direction Y. Both the second side surface 142a and the arcuate portion 1122 are arc surfaces. Along the thickness direction Z, the center of the circle corresponding to the projection of the second side surface 142a coincides with the center of the circle corresponding to the projection of the arcuate portion 1122. The difference between the radius of the circle corresponding to the projection of the arcuate portion 1122 and the radius of the circle corresponding to the projection of the second side surface 142a is r, where 0.1mm ≤ r ≤ 2mm.

[0221] The first current collector 1111 includes two first surfaces 1111a disposed opposite each other along the thickness direction Z, a first end face 111a connecting the two first surfaces 1111a, and a first film layer 1112 disposed on the first surface 1111a. The first film layer 1112 and the first end face 111a are spaced apart along the first direction X, and the insulating body 141 covers a portion of the first surface 1111a and a portion of the first film layer 1112 along the thickness direction Z.

[0222] The portion of the first film layer 1112 covered by the insulating body 141 has a dimension d1 along the first direction X, where 0.1mm ≤ d1 ≤ 2mm. The dimension of the insulating body 141 extending beyond the first end face 111a along the first direction X is d2, where 0.1mm ≤ d2 ≤ 6mm. Along the first direction X, the distance between the third end face 142c of the protrusion 142 away from the insulating body 141 and the first end face 111a is d3, where 6mm ≤ d2 ≤ 15mm.

[0223] 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, The battery cell includes a housing and an electrode assembly accommodated in the housing, the electrode assembly including an insulating member, and first and second polar tabs having opposite polarities; the first polar tab includes a first polar tab body and a first tab ear led out from a first end surface of the first polar tab body in a first direction, the first tab ear having two first side surfaces oppositely arranged in a second direction, the first direction, the second direction and a thickness direction of the first polar tab being perpendicular to each other; the insulating member is connected to the first polar tab, the insulating member including an insulating body and a protruding portion, at least a portion of the insulating body being arranged outside the first end surface in the first direction, the protruding portion protruding from a second end surface of the insulating body in the first direction, at least a portion of the protruding portion being arranged outside the first side surface in the second direction, the first tab ear exceeding the protruding portion in the first direction away from the first polar tab body; the protruding portion has two second side surfaces oppositely arranged in the second direction, the second side surfaces and the second end surface being smoothly connected.

2. The battery cell according to claim 1, wherein in the thickness direction, a projection of the second side surface is circular arc-shaped, the projection of the second side surface and a projection of the second end surface being tangent to each other.

3. The battery cell according to claim 1 or 2, wherein the first side surface includes a flat portion and an arc-shaped portion, in the first direction, the arc-shaped portion being connected between the flat portion and the first end surface; at least a portion of the second side surface is arranged outside the arc-shaped portion in the second direction, the second side surface having a same bending tendency as the arc-shaped portion.

4. The battery cell according to claim 3, wherein the second side surface and the arc-shaped portion are both circular arc surfaces, in the thickness direction, a center of a circle corresponding to a projection of the second side surface coincides with a center of a circle corresponding to a projection of the arc-shaped portion; a first radius of the circle corresponding to the projection of the arc-shaped portion is r1, a second radius of the circle corresponding to the projection of the second side surface is r2, 0.1mm≤r1-r2≤2mm.

5. The battery cell according to claim 1, wherein the insulating body includes two insulating portions oppositely arranged in the thickness direction; the insulating portions include first and second sub-portions, the first sub-portions of the two insulating portions are respectively arranged on both sides of the first polar tab body in the thickness direction and connected to the first polar tab body, the second sub-portions of the two insulating portions are arranged outside the first end surface in the first direction and connected to each other, the second sub-portions covering at least a portion of the first end surface.

6. The battery cell according to claim 5, wherein the protruding portion includes two sub-protruding portions oppositely arranged in the thickness direction, the two sub-protruding portions are respectively connected to the two insulating portions, a portion of the first tab ear is sandwiched between the two sub-protruding portions.

7. The battery cell according to claim 6, wherein The second sub-section has a third end surface facing away from the first sub-section along the first direction, and projections of the third end surfaces of the two second sub-sections overlap along the thickness direction, and the second end surface comprises the third end surfaces of the two second sub-sections; The sub-protrusions have two third side surfaces opposite along the second direction, and projections of the third side surfaces of the two sub-protrusions at least partially overlap along the thickness direction, and the second side surface comprises the third side surfaces of the two sub-protrusions; The third side surface of each sub-protrusion is smoothly connected to the third end surface of the insulating section connected thereto.

8. The battery cell of claim 6, wherein The sub-protrusion comprises a protruding body and two extension sections, and the protruding body is connected between the two extension sections along the second direction; The protruding body is arranged on one side of the first tab along the thickness direction, and the two extension sections are arranged on two sides of the first tab along the second direction; The extension section covers a part of the second side surface.

9. The battery cell of claim 5, wherein The first tab body comprises a first current collecting body and a first film layer, the first current collecting body comprises two first surfaces opposite along the thickness direction, and the first end surface connects the two first surfaces, and the first film layer is arranged on the first surface; The first film layer and the first end surface are arranged apart along the first direction, and the first sub-section covers a part of the first surface and a part of the first film layer along the thickness direction.

10. The battery cell of claim 9, wherein The first film layer comprises a main film region and a thinned region connected to the main film region, the thinned region is located on a side of the main film region close to the first end surface along the first direction, and a thickness of the thinned region is less than a thickness of the main film region; The first sub-section covers at least part of the thinned region along the thickness direction, and a projection of the first sub-section and a projection of the main film region are apart along the thickness direction.

11. The battery cell of claim 9, wherein A dimension of the part of the first film layer covered by the first sub-section along the first direction is d1, and 0.1mm≤d1≤2mm.

12. The battery cell of claim 5, wherein A dimension of the second sub-section along the first direction is d2, and 0.1mm≤d2≤6mm.

13. The battery cell of claim 5, wherein A thickness of the insulating section is h, and 9μm≤h≤30μm.

14. The battery cell of claim 1, wherein A distance between a third end surface of the protruding section away from the insulating body and the first end surface along the first direction is d3, and 6mm≤d3≤15mm.

15. The battery cell of claim 1, wherein The insulating piece comprises a base material layer and a glue layer, and the base material layer is connected to the first tab through the glue layer; A peel strength of the insulating piece is 15N / m-20N / m.

16. The battery cell according to claim 1, characterized in that, the puncture strength of the insulating member is greater than or equal to 410 gf.

17. A battery device characterized by comprising: a plurality of battery cells according to any one of claims 1 to 16.

18. An electrical device, characterized by a battery device according to claim 17 for providing electrical energy.

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