Battery monomer, battery and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery and a power utilization device. The battery monomer comprises a shell, a top cover and an electrode assembly, the housing has an accommodation space and an opening. And the top cover hermetically covers the opening. The electrode assembly is arranged in the accommodating space. The top cover comprises a cover body and a connecting piece, and the cover body is provided with a channel penetrating through the cover body. The connecting piece is arranged on the side, close to the electrode assembly, of the cover body and seals the channel. According to the battery monomer provided by the embodiment of the invention, the strength of the top cover at the channel can be weakened, and when the electrode assembly circularly expands and generates gas during charging and discharging, a force is generated on the joint of the shell and the top cover, and the force is easily transmitted to the area of the top cover at the channel; therefore, the stress of the connecting structure between the shell and the top cover is reduced, the risk of fatigue cracking of the connecting structure between the shell and the top cover is reduced, the problem of failure of the connecting structure between the shell and the top cover is improved, and the service life of the single battery is prolonged.

Description

Technical Field

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

[0002] This section is intended to provide a background or context for the embodiments of the present application. No description herein is admitted to be prior art by virtue of its inclusion in this section.

[0003] In the production process of battery cells, after placing the bare cell into the shell and closing the top cover, a cell with a shell can be obtained. After the bare cell is placed in the shell, the shell cover needs to be welded to weld the shell and the top cover together. In the related art, when the bare cell expands during the cycle and generates gas during the charge and discharge process, it will cause cracks at the connection between the shell and the top cover, and there is a problem of causing the connection structure between the shell and the top cover to fail. Utility Model Content

[0004] In view of this, the embodiments of the present application hope to provide a battery cell, a battery and an electrical device, which can improve the problem of failure of the connection structure between the outer shell and the top cover and increase the service life of the battery cell.

[0005] To achieve the above-mentioned purpose, a first aspect of an embodiment of the present application provides a battery cell, comprising:

[0006] A housing having a receiving space and an opening;

[0007] A top cover, a sealing cover is arranged at the opening;

[0008] An electrode assembly is disposed in the accommodation space;

[0009] The top cover includes a cover body and a connecting piece, the cover body has a channel penetrating the cover body, and the connecting piece is arranged on a side of the cover body close to the electrode assembly and closes the channel.

[0010] In the battery cell provided in the embodiment of the present application, the top cover sealing cover is arranged at the opening of the outer shell, and the cover body is provided with a channel penetrating the cover body, and a connecting piece is provided on the side of the cover body close to the electrode assembly to close the channel. That is to say, the strength of the top cover at the channel can be weakened. Therefore, when the electrode assembly cyclically expands and generates gas during charging and discharging, when force is exerted on the connection between the outer shell and the top cover, the force is more easily transmitted to the area of ​​the top cover at the channel. That is to say, the area of ​​the top cover at the channel is equivalent to forming a force buffer zone at the connection between the outer shell and the top cover, thereby reducing the force on the connection structure between the outer shell and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover, improving the problem of failure of the connection structure between the outer shell and the top cover, and improving the service life of the battery cell.

[0011] In some embodiments, the channel extends along an edge of the cover body.

[0012] The distances between any two positions of the channel in its extending direction and the housing can be made the same, so that the force near the channel can be made more uniform.

[0013] In some embodiments, the connecting member is recessed toward a side away from the channel to form a groove, and the groove is communicated with the channel.

[0014] This makes the area of ​​the top cover located at the channel more prone to deformation, further alleviates the stress on the connection between the outer shell and the top cover, and further reduces the risk of fatigue cracking of the connection structure between the outer shell and the top cover.

[0015] In some embodiments, at least a portion of the side wall of the connector away from the channel protrudes so that the corresponding side wall of the connector close to the channel is recessed to form the groove; or, at least a portion of the side wall of the connector close to the channel is thinned to form the groove.

[0016] For example, by using a processing technique such as milling or planing to thin at least a portion of the side wall of the connector near the channel to form a groove, the groove formed by this processing method has high precision and is easy to form. In this embodiment, the structural strength of the groove can be further reduced so that the area of ​​the top cover located at the channel is more prone to deformation.

[0017] For example, by stamping, at least a portion of the side wall of the connecting member away from the channel is convex, so that the side wall of the connecting member corresponding to the side close to the channel is concave to form a groove.

[0018] In some embodiments, in a cross section perpendicular to the extension direction of the channel, the cross-sectional shape of the groove is one of an arc shape, a U shape and a polygon shape.

[0019] Here, the groove can have different cross-sectional shapes according to requirements.

[0020] In some embodiments, the cover body is provided with a circle of the channels corresponding to the contour of the cover body.

[0021] In this embodiment, the cover body can form a circle of strength weakening structure in the area of ​​the cover body close to the connection with the outer shell by providing a circle of channels corresponding to the contour of the cover body. As a result, the force at the connection between the outer shell and the top cover can be more easily transmitted to the area of ​​the top cover located at the channel, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover.

[0022] In some embodiments, the cover body is rectangular, and at least one long side of the cover body is provided with the channel corresponding to the outline of the cover body.

[0023] In this embodiment, by providing a channel corresponding to the contour of the cover body on at least one long side of the cover body, while the top cover has sufficient structural strength, the force at the connection between the outer shell and the top cover can be easily transmitted to the area of ​​the top cover located at the channel, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover.

[0024] In some embodiments, in a cross section perpendicular to an extension direction of the channel, a width of the channel is L1, wherein 0.5 mm ≤ L1 ≤ 10 mm.

[0025] By setting the width of the channel to 0.5mm-10mm, the top cover can have sufficient strength, and the force at the connection between the outer shell and the top cover can be transferred to the channel, which is more conducive to concentrating the deformation at the channel, thereby reducing the force on the connection structure between the outer shell and the top cover, reducing the risk of cracking of the connection structure between the outer shell and the top cover, and improving the service life of the top cover.

[0026] In some embodiments, in a cross section perpendicular to an extension direction of the channel, a width of the channel is L1, wherein 0.8 mm ≤ L1 ≤ 3 mm.

[0027] By setting the width of the channel to 0.8mm-3mm, the force at the connection between the shell and the top cover can be transferred to the channel, which helps to concentrate the deformation on the channel. At the same time, it can further make the top cover have sufficient strength and improve the service life of the top cover.

[0028] In some embodiments, the thickness of the connection between the shell and the cover body is L2, and the thickness of the groove wall of the groove is L3, wherein L2≤L3≤4L2.

[0029] By setting the thickness of the groove wall to L2-4L2, the connecting piece can have sufficient strength to improve the reliability of the top cover, while also helping to concentrate the deformation at the groove, thereby reducing the stress on the connecting structure between the outer shell and the top cover, and reducing the risk of cracking of the connecting structure between the outer shell and the top cover.

[0030] In some embodiments, the thickness of the connection between the shell and the cover body is L2, and the thickness of the groove wall of the groove is L3, wherein L2≤L3≤2L2.

[0031] By setting the thickness of the groove wall to L2-2L2, the connecting piece can have sufficient strength to improve the reliability of the top cover, while further facilitating the concentration of deformation at the groove, thereby reducing the stress on the connecting structure between the outer shell and the top cover, and further reducing the risk of cracking of the connecting structure between the outer shell and the top cover.

[0032] In some embodiments, the distance between the channel and the housing is L4, where 1 mm ≤ L4 ≤ 10 mm.

[0033] By setting the distance between the channel and the shell to 1mm-10mm, the top cover can have sufficient strength, thereby improving the structural strength of the connection between the top cover and the shell. At the same time, the channel on the top cover can be set as close to the shell as possible, which is more conducive to the force at the connection between the shell and the top cover being transmitted to the channel, thereby facilitating the deformation to be concentrated at the channel, thereby reducing the force on the connection structure between the shell and the top cover, and reducing the risk of cracking of the connection structure between the shell and the top cover.

[0034] In some embodiments, the thickness of the connection between the shell and the cover body is L2, and the distance between the channel and the shell is L4, wherein 2L2≤L4≤4mm.

[0035] By setting the distance between the channel and the shell to 2L2-4mm, the top cover can have sufficient strength, thereby improving the structural strength of the connection between the top cover and the shell. At the same time, the channel on the top cover can be further set as close to the shell as possible, which is more conducive to the force at the connection between the shell and the top cover to be transferred to the channel, thereby further facilitating the deformation to be concentrated in the channel, thereby further reducing the force on the connection structure between the shell and the top cover, and reducing the risk of cracking of the connection structure between the shell and the top cover.

[0036] In some embodiments, a dimension of the cover body in a height direction of the shell is H, wherein 1mm≤H≤5mm; and / or a thickness of a connection between the shell and the cover body is L2, wherein 0.4mm≤L2≤2mm.

[0037] In some embodiments, a dimension of the cover body in a height direction of the shell is H, wherein 1.5 mm ≤ H ≤ 3 mm; and / or a thickness of a connection between the shell and the cover body is L2, wherein 0.6 mm ≤ L2 ≤ 1.7 mm.

[0038] In this embodiment, by setting the height of the cover body to 1mm-5mm, the top cover can have sufficient strength to protect the electrode assembly in the accommodating space while reducing the weight and volume of the battery cell, and can reduce the material used for the top cover, reduce costs, and improve the overall performance of the battery.

[0039] By setting the height of the cover body to 1.5mm-3mm, the top cover can have sufficient strength to protect the electrode assembly in the accommodating space, while further reducing the weight and volume of the battery cell, reducing the material used for the top cover, reducing costs, and further improving the overall performance of the battery.

[0040] By setting the thickness of the connection between the shell and the cover body to 0.4mm-2mm, the connection between the top cover and the shell has sufficient connection strength, while reducing the weight and volume of the battery cell, reducing the material used for the top cover, reducing costs, and improving the overall performance of the battery.

[0041] By setting the thickness of the connection between the shell and the cover body to 0.6mm-1.7mm, the connection between the top cover and the shell has sufficient connection strength, while further reducing the weight and volume of the battery cell, reducing the material used for the top cover, reducing costs, and further improving the overall performance of the battery.

[0042] A second aspect of an embodiment of the present application provides a battery, comprising at least one battery cell as described above.

[0043] The battery provided in the embodiment of the present application includes at least one battery cell of the embodiment of the present application, and the top cover sealing cover is arranged at the opening of the outer shell, and the cover body is provided with a channel penetrating the cover body, and a connecting piece is provided on the side of the cover body close to the electrode assembly to close the channel, that is, the strength of the top cover at the channel can be weakened, thereby, when the electrode assembly cyclically expands and generates gas during charging and discharging and generates force on the connection between the outer shell and the top cover, the force is more easily transmitted to the area of ​​the top cover at the channel, that is, the area of ​​the top cover at the channel is equivalent to forming a force buffer zone at the connection between the outer shell and the top cover, thereby reducing the force on the connection structure between the outer shell and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover, improving the problem of failure of the connection structure between the outer shell and the top cover, and improving the service life of the battery cell.

[0044] A third aspect of an embodiment of the present application provides an electrical device, comprising the battery described above, wherein the battery is used to provide electrical energy to the electrical device.

[0045] The electrical device provided in the embodiment of the present application includes a battery, and the battery includes at least one battery cell of the embodiment of the present application. The top cover sealing cover is arranged at the opening of the outer shell, and the cover body is provided with a channel penetrating the cover body, and a connecting piece is provided on the side of the cover body close to the electrode assembly to close the channel. That is to say, the strength of the top cover at the channel can be weakened. Therefore, when the electrode assembly cyclically expands and generates gas during charging and discharging, when force is applied to the connection between the outer shell and the top cover, the force is more easily transmitted to the area of ​​the top cover at the channel. That is to say, the area of ​​the top cover at the channel is equivalent to forming a force buffer zone at the connection between the outer shell and the top cover, thereby reducing the force on the connection structure between the outer shell and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover, improving the problem of failure of the connection structure between the outer shell and the top cover, and increasing the service life of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 A schematic diagram of the structure of a vehicle provided in one embodiment of the present application;

[0047] Figure 2 A three-dimensional exploded schematic diagram of a battery provided in one embodiment of the present application;

[0048] Figure 3 A top view of a battery cell provided in one embodiment of the present application;

[0049] Figure 4 An exploded view of a battery cell provided in an embodiment of the present application, wherein the electrode assembly is omitted;

[0050] Figure 5 for Figure 3 Section view in AA direction;

[0051] Figure 6 for Figure 5 The enlarged view of point B in the middle;

[0052] Figure 7 A schematic diagram of the deformation of the connection between the housing and the top cover provided in one embodiment of the present application when subjected to force;

[0053] Figure 8 The figure is a schematic diagram of cracking of the connection between the shell and the top cover in the prior art when subjected to stress.

[0054] Description of Reference Numerals

[0055] 10. Battery cell; 11. Shell; 11a. Accommodation space; 11b. Opening; 12. Top cover; 121. Cover body; 121a. Channel; 122. Connector; 122a. Groove; 20. Battery box; 21. First box body; 22. Second box body; 100. Battery; 200. Controller; 300. Motor; 1000. Vehicle. DETAILED DESCRIPTION

[0056] It should be noted that, in the absence of conflict, the embodiments and technical features in the embodiments of the present application can be combined with each other, and the detailed description in the specific implementation method should be understood as an explanation of the purpose of the present application and should not be regarded as an improper limitation on the present application.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions.

[0058] In the description of the embodiments of the present application, the technical terms "first", "second", "third", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0059] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0060] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0061] In the description of the embodiments of the present application, the orientation or position relationship indicated by technical terms such as "length", "width", "thickness", "height", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "circumferential", "height direction", "first direction", and "second direction" are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present application.

[0062] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0063] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, the technical term "contact" should be understood in a broad sense, and may be direct contact or contact through an intermediate medium layer. It may be contact with essentially no interaction force between the two contacting parties, or it may be contact with interaction force between the two contacting parties.

[0064] With the development of clean energy, more and more devices use electric energy as driving energy, and then power batteries that can store more electric energy and can be charged and discharged repeatedly are developing rapidly, such as lithium-ion batteries. Among them, power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, electric cars, as well as aerospace and other fields.

[0065] With the country's vigorous promotion of new energy vehicles, new energy vehicles have ushered in a great opportunity for development. The safety and stability of automobiles have always been people's greatest concern. Therefore, improving the safety of new energy vehicles will be one of the important factors that determine whether new energy vehicles can be quickly popularized. Improving the safety of batteries is an important way to improve the safety of new energy vehicles.

[0066] In the present application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery or a magnesium-ion battery, etc., which is not limited in the embodiments of the present application. The battery cell may be cylindrical, rectangular or in other shapes, etc., which is not limited in the embodiments of the present application.

[0067] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0068] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide, etc. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode collector. The negative electrode collector not coated with the negative electrode active material layer protrudes from the negative electrode collector coated with the negative electrode active material layer. The negative electrode collector not coated with the negative electrode active material layer serves as the negative electrode tab. The negative electrode current collector may be made of copper, and the negative electrode active material may be carbon or silicon. In order to ensure that a large current can pass without melting, the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together. The material of the separator may be PP (polypropylene) or PE (polyethylene).

[0069] The battery cell also includes a packaging film and a shell. The packaging film is coated on the outside of the electrode assembly, and the shell encapsulates the electrode assembly coated with the packaging film to form a battery cell. The packaging film can be a Mylar film, and the shell can be an aluminum shell. After the electrode assembly is wound and formed, the Mylar film and the shell are encapsulated through the Mylar wrapping process and the shelling process. Among them, the Mylar film plays a role in sealing and protecting the electrode assembly, and the Mylar film can effectively insulate the electrode assembly and the shell from each other to avoid internal short circuits in the battery cell. The shell plays a protective role.

[0070] For related technologies, see Figure 8 When gas is generated during the cyclic expansion of the electrode assembly and the charge and discharge process, force is exerted on the outer shell and the top cover, causing the outer shell to deform outward, thereby stretching the connection structure between the outer shell and the top cover, and further causing fatigue cracking at the connection between the outer shell and the top cover, which may cause the connection structure between the outer shell and the top cover to fail.

[0071] In order to improve the problem of failure of the connection structure between the outer shell and the top cover and to increase the service life of the battery cell, an embodiment of the present application provides a battery cell, which includes an outer shell, a top cover and an electrode assembly. The outer shell has a receiving space and an opening. The top cover sealing cover is arranged at the opening. The electrode assembly is arranged in the receiving space. Among them, the top cover includes a cover body and a connector, and the cover body has a channel penetrating the cover body. The connector is arranged on the side of the cover body close to the electrode assembly and closes the channel.

[0072] In the battery cell provided in the embodiment of the present application, the top cover sealing cover is arranged at the opening of the outer shell, and the cover body is provided with a channel penetrating the cover body, and a connecting piece is provided on the side of the cover body close to the electrode assembly to close the channel. That is to say, the strength of the top cover at the channel can be weakened. Therefore, when the electrode assembly cyclically expands and generates gas during charging and discharging, when force is exerted on the connection between the outer shell and the top cover, the force is more easily transmitted to the top cover at the channel. That is to say, the area of ​​the top cover at the channel is equivalent to forming a force buffer zone at the connection between the outer shell and the top cover, thereby reducing the force on the connection structure between the outer shell and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover, improving the problem of failure of the connection structure between the outer shell and the top cover, and improving the service life of the battery cell.

[0073] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0074] The battery mentioned in the embodiments of the present application refers to a battery cell including at least one battery cell provided in the embodiments of the present application. One or more battery cells provide a single physical module with higher voltage and capacity. For example, the battery mentioned in the present application may include a battery module or a battery pack. The battery generally includes a box for encapsulating one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cells.

[0075] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0076] It should be noted that the technical solutions described in the embodiments of the present application are not limited to the batteries and electrical devices described above, but can also be applied to all batteries including a box and electrical devices using batteries. However, for the sake of simplicity, the following embodiments are described using electric vehicles as examples.

[0077] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle 1000 provided for some embodiments of the present application. A controller 200, a motor 300 and a battery 100 may be provided inside the vehicle 1000, and the controller 200 is used to control the battery 100 to power the motor 300. For example, a battery 100 may be provided at the bottom, front or rear of the vehicle 1000. The battery 100 may be used to power the vehicle 1000, for example, the battery 100 may be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1000. In another embodiment of the present application, the battery 100 may not only be used as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0078] In order to meet different power requirements, the battery 100 may include a plurality of battery cells 10, which refers to the smallest unit constituting the battery 100 module or the battery 100 pack. A plurality of battery cells 10 may be connected in series, in parallel or in hybrid connection, and hybrid connection means that a plurality of battery cells 10 are both connected in series and in parallel. A plurality of battery cells 10 may be directly connected in series, in parallel or in hybrid connection, and then the whole formed by the plurality of battery cells 10 is accommodated in the box; of course, the battery 100 may also be a plurality of battery cells 10 connected in series, in parallel or in hybrid connection to form a battery 100 module, and a plurality of battery 100 modules are then connected in series, in parallel or in hybrid connection to form a whole, and are accommodated in the box. The battery 100 may also include other structures, for example, the battery 100 may also include a confluence component for realizing electrical connection between a plurality of battery cells 10. Among them, each battery cell 10 may be a secondary battery 100 or a primary battery 100; it may also be a lithium-sulfur battery 100, a sodium-ion battery 100 or a magnesium-ion battery 100, but is not limited thereto. The battery cell 10 may be cylindrical, flat, rectangular or in other shapes.

[0079] The battery 100 includes a battery box 20 and at least one battery cell 10 , and the battery cell 10 is disposed in an installation space of the battery box 20 .

[0080] The battery box 20 can be a simple three-dimensional structure such as a single cuboid, cylinder or sphere, or a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders or spheres. The material of the battery box 20 can be alloy materials such as aluminum alloy, iron alloy, etc., or polymer materials such as polycarbonate, polyisocyanurate foam plastics, or composite materials such as glass fiber and epoxy resin.

[0081] The battery box 20 is used to accommodate the battery cell 10, and the battery box 20 can be a variety of structures. In some embodiments, the battery box 20 may include a first box body 21 and a second box body 22, the first box body 21 and the second box body 22 cover each other, and the first box body 21 and the second box body 22 jointly define an installation space for accommodating the battery cell 10. The second box body 22 may be a hollow structure with one end open, the first box body 21 is a plate-like structure, and the first box body 21 covers the open side of the second box body 22 to form a battery box 20 with an installation space; the first box body 21 and the second box body 22 may also be a hollow structure with one side open, and the open side of the first box body 21 covers the open side of the second box body 22 to form a battery box 20 with an installation space. Of course, the first box body 21 and the second box body 22 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0082] In order to improve the sealing performance after the first box body 21 and the second box body 22 are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 21 and the second box body 22 .

[0083] Assuming that the first box body portion 21 covers the top of the second box body portion 22 , the first box body portion 21 can also be referred to as an upper box cover, and the second box body portion 22 can also be referred to as a lower box cover.

[0084] In the battery 100, there can be one or more battery cells 10. If there are more than one battery cell 10, the battery cells 10 can be connected in series, in parallel or in a mixed connection. A mixed connection means that the battery cells 10 are connected in series and in parallel. The battery cells 10 can be directly connected in series, in parallel or in a mixed connection, and then the whole formed by the battery cells 10 is accommodated in the battery box 20; of course, the battery cells 10 can also be connected in series, in parallel or in a mixed connection to form a battery module 100, and then the battery modules 100 are connected in series, in parallel or in a mixed connection to form a whole, and then accommodated in the battery box 20.

[0085] Exemplarily, the battery cell 10 may include a lithium-ion battery cell 10, a sodium-ion battery cell 10, or a magnesium-ion battery cell 10, etc., which is not limited in the embodiments of the present application. The battery cell 10 may be cylindrical, flat, rectangular, or in other shapes, etc., which is not limited in the embodiments of the present application. The battery cell 10 is generally divided into three types according to the packaging method: cylindrical battery cells 10, square battery cells 10, and soft-pack battery cells 10, which is not limited in the embodiments of the present application.

[0086] The present application embodiment provides a battery cell 10. Figures 3 to 6The battery cell 10 includes a housing 11, a top cover 12 and an electrode assembly. The housing 11 has a receiving space 11a and an opening 11b. The sealing cover of the top cover 12 is arranged at the opening 11b. The electrode assembly is arranged in the receiving space 11a. The top cover 12 includes a cover body 121 and a connector 122, and the cover body 121 has a channel 121a penetrating the cover body 121. The connector 122 is arranged on the side of the cover body 121 close to the electrode assembly and closes the channel 121a.

[0087] Here, the housing 11 may be cylindrical, flat, rectangular or in other shapes.

[0088] It should be noted that the height direction described in the embodiment of the present application is the direction from the opening 11b to the accommodating space 11a, or the opposite direction from the opening 11b to the accommodating space 11a. When the housing 11 is cylindrical, the height direction of the housing 11 is the axial direction of the housing 11.

[0089] It should be noted that the specific method of connecting the top cover 12 and the housing 11 is not limited here, for example, welding.

[0090] Exemplarily, the cover body 121 and the connecting member 122 are an integrated structure. The integrated cover body 121 and the connecting member 122 can reduce the number of parts, reduce assembly time, and improve assembly efficiency and structural strength.

[0091] Of course, the cover body 121 and the connector 122 may also be a split structure, for example, the connector 122 is welded to the side of the cover body 121 close to the electrode assembly. The split cover body 121 and connector 122 are conducive to molding.

[0092] The cover body 121 has a channel 121a that penetrates the cover body 121, that is, the channel 121a penetrates both ends of the cover body 121 along the height direction of the battery cell 10, so that the structural strength of the top cover 12 at the channel 121a can be weakened, so that when the electrode assembly cyclically expands and generates gas during charge and discharge, when a force is applied to the connection between the housing 11 and the top cover 12, the force is more easily transmitted to the area of ​​the top cover 12 located at the channel 121a, for example, so that the area of ​​the top cover 12 located at the channel 121a is deformed (such as Figure 7 Compared with only grooving the cover body 121, the channel 121a of the embodiment of the present application penetrates the cover body 121, which can further facilitate the transmission of the force at the connection between the housing 11 and the top cover 12 to the area of ​​the top cover 12 located at the channel 121a.

[0093] The top cover 12 is generally perpendicular to the side of the outer shell 11, and the outer shell 11 deforms outward, and a shear force parallel to the top cover 12 is generated at the connection between the outer shell 11 and the top cover 12. When the electrode assembly expands cyclically and generates gas during charging and discharging, the force exerted on the outer shell 11 can be concentrated at the channel 121a of the top cover 12, thereby reducing the shear force on the connection between the outer shell 11 and the top cover 12, reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12, improving the problem of failure of the connection structure between the outer shell 11 and the top cover 12, and improving the service life of the battery cell 10.

[0094] In the battery cell 10 provided in the embodiment of the present application, the top cover 12 sealing cover is arranged at the opening 11b of the outer shell 11, and the cover body 121 is provided with a channel 121a that penetrates the cover body 121, and a connector 122 is provided on the side of the cover body 121 close to the electrode assembly to close the channel 121a. That is to say, the strength of the top cover 12 at the channel 121a can be weakened. Therefore, when the electrode assembly cyclically expands and generates gas during charging and discharging, when a force is exerted on the connection between the outer shell 11 and the top cover 12, the force is more easily transmitted to the top cover 12 at the channel 121a. That is to say, the area of ​​the top cover 12 at the channel 121a is equivalent to forming a force buffer zone at the connection between the outer shell 11 and the top cover 12, thereby reducing the force on the connection structure between the outer shell 11 and the top cover 12, reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12, improving the problem of failure of the connection structure between the outer shell 11 and the top cover 12, and improving the service life of the battery cell 10.

[0095] It should be noted that the extension direction of the channel 121a is not limited here. Figure 3 and Figure 4 , the extending direction of the channel 121 a is the same as the extending direction of the outline of the cover body 121 .

[0096] Here, the extension direction of the channel 121a is the same as the extension direction of the outline of the cover body 121, that is, when projected on a plane parallel to the top cover 12, the outline shape of the center line of the channel 121a along the extension direction is completely the same or approximately the same as the outline shape of the cover body 121.

[0097] It can be understood that the extension direction of the channel 121a is the same as the extension direction of the outline of the cover body 121, so that the distance between any two positions of the channel 121a in its extension direction and the shell 11 are the same, so that the force near the channel 121a can be more uniform.

[0098] It should be noted that the cover body 121 may be formed with the channel 121a in a partial area near the edge of the cover body 121, or may be formed with the channel 121a in the entire area near the edge of the cover body 121, that is, the cover body 121 is provided with a circle of channels 121a corresponding to the outline of the cover body 121. Here, the outline of the cover body 121 refers to the side wall where the top cover 12 is connected to the housing 11.

[0099] For example, when the housing 11 is cylindrical, a circle of channels 121 a may be provided on the circumference of the cover body 121 , or the channels 121 a may be provided partially around the cover body 121 .

[0100] When the housing 11 is rectangular, the channel 121a may be formed partially or entirely on the long side or partially or entirely on the short side. In some embodiments, the cover body 121 is provided with a circle of channels 121a corresponding to the outline of the cover body 121.

[0101] Here, the channel 121 a corresponding to the outline of the cover body 121 means that the extending direction of the channel 121 a set on the cover body 121 is substantially the same as or completely the same as the outline of the cover body 121 .

[0102] In this embodiment, the cover body 121 can form a circle of strength weakening structure in the area where the cover body 121 is close to the connection with the outer shell 11 by setting a circle of channels 121a extending along the edge of the cover body 121. As a result, the force at the connection between the outer shell 11 and the top cover 12 can be more easily transmitted to the area of ​​the top cover 12 located at the channel 121a, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12.

[0103] In some other embodiments, please refer to Figure 4 At least one long side of the cover body 121 is provided with a channel 121a corresponding to the outline of the cover body 121, that is, the cover body 121 can have one long side corresponding to the channel 121a, or two long sides can have the channel 121a corresponding to the two short sides, while no channel 121a is provided correspondingly.

[0104] In this embodiment, by providing a channel 121a corresponding to the contour of the cover body 121 on at least one long side of the cover body 121, while the top cover 12 has sufficient structural strength, the force at the connection between the outer shell 11 and the top cover 12 can be easily transmitted to the area of ​​the top cover 12 located at the channel 121a, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12.

[0105] In some embodiments, see Figures 3 to 6The connecting member 122 is recessed toward a side away from the channel 121 a to form a groove 122 a , and the groove 122 a is communicated with the channel 121 a .

[0106] Exemplarily, the groove 122a corresponds to the channel 121a, that is, the extending direction of the groove 122a is substantially the same as or completely the same as the extending direction of the channel 121a.

[0107] Here, the connecting member 122 is recessed toward the side away from the channel 121a to form a groove 122a, which is equivalent to increasing the depth of the groove on the top cover 12. Here, the depth of the groove is equal to the sum of the depth of the channel 121a and the depth of the groove 122a.

[0108] In this embodiment, the connecting member 122 is recessed toward the side away from the channel 121a to form a groove 122a, so that the area of ​​the top cover 12 located at the channel 121a is more prone to deformation, further alleviating the stress at the connection between the outer shell 11 and the top cover 12, and further reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12.

[0109] It should be noted that there are many ways to form the groove 122 a.

[0110] In some embodiments, at least a portion of the sidewall of the connecting member 122 close to the channel 121 a is thinned to form a groove 122 a .

[0111] Here, part of the side wall of the connecting member 122 close to the channel 121 a may be thinned to form the groove 122 a , or the entire side wall of the connecting member 122 close to the channel 121 a may be thinned to form the groove 122 a .

[0112] In this embodiment, at least a portion of the side wall of the connecting member 122 close to the channel 121 a is thinned to form a groove 122 a , that is, the thickness of the groove wall of the groove 122 a is smaller than the wall thickness of other areas of the connecting member 122 .

[0113] For example, at least a portion of the side wall of the connector 122 near the channel 121a is thinned by milling, planing or other processing techniques to form the groove 122a. The groove 122a formed by this processing method has high precision and is easy to form. In this embodiment, the structural strength of the groove 122a can be further reduced so that the area of ​​the top cover 12 located at the channel 121a is more prone to deformation.

[0114] In some other embodiments, please refer to Figure 6 At least a portion of the side wall of the connecting member 122 away from the channel 121a protrudes, so that the side wall of the connecting member 122 corresponding to the side close to the channel 121a is recessed to form a groove 122a.

[0115] Here, part of the side wall of the connecting member 122 away from the channel 121a may protrude, so that the corresponding side wall of the connecting member 122 close to the channel 121a is recessed to form the groove 122a; or the entire side wall of the connecting member 122 away from the channel 121a may protrude, so that the corresponding side wall of the connecting member 122 close to the channel 121a is recessed to form the groove 122a.

[0116] In this embodiment, the thickness of the groove wall of the groove 122 a is equal to the wall thickness of the connecting member 122 .

[0117] For example, by stamping, at least a portion of the side wall of the connecting member 122 away from the channel 121 a is protruded, so that the side wall of the connecting member 122 corresponding to the side close to the channel 121 a is recessed to form a groove 122 a.

[0118] It should be noted that the cross-sectional shape of the groove 122 a is not limited here.

[0119] In some embodiments, in a cross section perpendicular to the extension direction of the channel 121 a , the cross-sectional shape of the groove 122 a is one of an arc shape, a U shape, and a polygon shape.

[0120] Exemplarily, the arc is, for example, a semicircle.

[0121] The polygon is, for example, a rectangle.

[0122] Here, the groove 122a can have different cross-sectional shapes according to requirements.

[0123] In some embodiments, see Figure 5 and Figure 6 The dimension of the cover body 121 in the height direction of the housing 11 is H, wherein 1 mm ≤ H ≤ 5 mm, for example, 1 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.7 mm, 2 mm, 3 mm, 3.4 mm, 3.5 mm, 3.7 mm, 4 mm, 4.3 mm, 4.5 mm, 4.7 mm or 5 mm, etc.

[0124] In this embodiment, by setting the height of the cover body 121 to 1mm-5mm, the top cover 12 can have sufficient strength to protect the electrode assembly in the accommodating space 11a, while reducing the weight and volume of the battery cell 10, and can reduce the material used for the top cover 12, reduce costs, and improve the overall performance of the battery 100.

[0125] In some other embodiments, please refer to Figure 5 and Figure 6The dimension of the cover body 121 in the height direction of the housing 11 is H, wherein 1.5 mm ≤ H ≤ 3 mm, for example, 1.5 mm, 1.6 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm or 3 mm, etc.

[0126] In this embodiment, by setting the height of the cover body 121 to 1.5mm-3mm, the top cover 12 can have sufficient strength to protect the electrode assembly in the accommodating space 11a, while further reducing the weight and volume of the battery cell 10, reducing the material used for the top cover 12, reducing costs, and further improving the overall performance of the battery 100.

[0127] In some embodiments, please refer to Figure 5 and Figure 6 The thickness of the connection between the housing 11 and the cover body 121 is L2, wherein 0.4 mm ≤ L2 ≤ 2 mm, for example, 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1 mm, 1.3 mm, 1.5 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2 mm.

[0128] The thickness of the connection between the outer shell 11 and the cover body 121 is L2, that is, the thickness of the outer shell 11 near the opening 11b is L2.

[0129] It should be noted that the housing 11 may include regions with different thicknesses. For example, along the height direction of the housing 11, the housing 11 includes a first region close to one end of the opening 11b and a second region away from one end of the opening 11b, that is, the thickness of the first region is L2. The thickness of the first region is different from the thickness of the second region.

[0130] Exemplarily, the thickness of the first region is greater than that of the second region. Since the first region is close to one end of the opening 11b, the top cover 12 is connected to the first region, and by setting the thickness of the first region to be greater than that of the second region, the connection strength of the top cover 12 and the housing 11 can be improved.

[0131] It should be noted that the height of the first area is not limited here, and at least needs to be connected to the top cover 12. Exemplarily, the height of the first area is not less than 10 mm.

[0132] In this embodiment, by setting the thickness of the connection between the outer shell 11 and the cover body 121 to 0.4mm-2mm, the connection between the top cover 12 and the outer shell 11 has sufficient connection strength, while reducing the weight and volume of the battery cell 10, reducing the material used for the top cover 12, reducing costs, and improving the overall performance of the battery 100.

[0133] For other embodiments, please refer to Figure 5 and Figure 6 The thickness of the connection between the housing 11 and the cover body 121 is L2, wherein 0.6 mm ≤ L2 ≤ 1.7 mm, for example, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm or 1.7 mm.

[0134] In this embodiment, by setting the thickness of the connection between the outer shell 11 and the cover body 121 to 0.6mm-1.7mm, the connection between the top cover 12 and the outer shell 11 has sufficient connection strength, while further reducing the weight and volume of the battery cell 10, reducing the material used for the top cover 12, reducing costs, and further improving the overall performance of the battery 100.

[0135] In some embodiments, see Figure 5 and Figure 6 In a cross section perpendicular to the extension direction of the channel 121a, the width of the channel 121a is L1, wherein 0.5mm≤L1≤10mm, for example, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 1mm, 2mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0136] Here, the width of the channel 121 a refers to the dimension of the channel 121 a in the thickness direction of the housing 11 .

[0137] It is understandable that the larger the width of the channel 121a, the more conducive it is for the force at the connection between the shell 11 and the top cover 12 to be transmitted to the channel 121a, that is, it is more conducive to concentrating the deformation at the channel 121a, but it will affect the structural strength of the top cover 12 at the channel 121a.

[0138] In this embodiment, by setting the width of the channel 121a to 0.5mm-10mm, the top cover 12 can have sufficient strength, and it is also beneficial for the force at the connection between the outer shell 11 and the top cover 12 to be transferred to the channel 121a, which is more conducive to concentrating the deformation at the channel 121a, thereby reducing the force on the connection structure between the outer shell 11 and the top cover 12, reducing the risk of cracking of the connection structure between the outer shell 11 and the top cover 12, and improving the service life of the top cover 12.

[0139] In some other embodiments, please refer to Figure 5 and Figure 6In a cross section perpendicular to the extension direction of the channel 121a, the width of the channel 121a is L1, wherein 0.8mm≤L1≤3mm, for example, 0.8mm, 0.9mm, 1mm, 1.2mm, 1.3mm, 1.5mm, 1.6mm, 1.8mm, 2mm, 2.2mm, 2.4mm, 2.5mm, 2.6mm, 2.8mm, 2.9mm or 3mm, etc.

[0140] In this embodiment, by setting the width of the channel 121a to 0.8mm-3mm, the force at the connection between the outer shell 11 and the top cover 12 can be transferred to the channel 121a, which helps to concentrate the deformation on the channel 121a. At the same time, the top cover 12 can be further made to have sufficient strength, thereby improving the service life of the top cover 12.

[0141] In some embodiments, see Figure 5 and Figure 6 , the thickness of the connection between the shell 11 and the cover body 121 is L2, and the thickness of the groove wall of the groove 122a is L3, wherein L2≤L3≤4L2. In other words, the thickness of the groove wall of the groove 122a is greater than or equal to the thickness of the connection between the shell 11 and the cover body 121, and less than or equal to 4 times the thickness of the connection between the shell 11 and the cover body 121.

[0142] It should be noted that the thickness of the connection between the housing 11 and the cover body 121 is the thickness of the first region.

[0143] Here, the side wall of the connecting member 122 away from the channel 121a protrudes, so that the side wall of the connecting member 122 corresponding to the side close to the channel 121a is recessed to form a groove 122a. Therefore, the thickness of the groove wall of the groove 122a is the thickness of the connecting member 122.

[0144] L3 is, for example, 1L2, 1.2L2, 1.3L2, 1.5L2, 1.6L2, 1.8L2, 2L2, 2.2L2, 2.5L2, 2.8L2, 3L2, 3.3L2, 3.5L2, 3.6L2, 3.7L2, 3.8L2, 3.9L2 or 4L2, etc.

[0145] In this embodiment, by setting the thickness of the groove wall of the groove 122a to L2-4L2, the connecting member 122 can have sufficient strength to improve the reliability of the top cover 12, while also facilitating the concentration of deformation at the groove 122a, thereby reducing the stress on the connecting structure between the outer shell 11 and the top cover 12, and reducing the risk of cracking of the connecting structure between the outer shell 11 and the top cover 12.

[0146] In some other embodiments, please refer to Figure 5 and Figure 6, the thickness of the connection between the shell 11 and the cover body 121 is L2, and the thickness of the groove wall of the groove 122a is L3, wherein L2≤L3≤2L2. In other words, the thickness of the groove wall of the groove 122a is greater than or equal to the thickness of the connection between the shell 11 and the cover body 121, and less than or equal to 2 times the thickness of the connection between the shell 11 and the cover body 121.

[0147] L3 is, for example, 1L2, 1.2L2, 1.3L2, 1.4L2, 1.5L2, 1.6L2, 1.7L2, 1.8L2, 1.9L2 or 2L2, etc.

[0148] In this embodiment, by setting the thickness of the groove wall of the groove 122a to L2-2L2, the connecting member 122 can have sufficient strength to improve the reliability of the top cover 12, while further facilitating the deformation to be concentrated at the groove 122a, thereby reducing the stress on the connecting structure between the outer shell 11 and the top cover 12, and further reducing the risk of cracking of the connecting structure between the outer shell 11 and the top cover 12.

[0149] In some embodiments, see Figure 5 and Figure 6 , the distance between the channel 121a and the housing 11 is L4, where 1mm≤L4≤10mm.

[0150] Here, the distance between the channel 121 a and the housing 11 is the distance between the side wall of the channel 121 a and the housing 11 .

[0151] L1 is, for example, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm or 10mm, etc.

[0152] In this embodiment, by setting the distance between the channel 121a and the outer shell 11 to 1mm-10mm, the top cover 12 can have sufficient strength, thereby improving the structural strength of the connection between the top cover 12 and the outer shell 11, and the channel 121a on the top cover 12 can be set as close to the outer shell 11 as possible, which is more conducive to the force at the connection between the outer shell 11 and the top cover 12 being transmitted to the channel 121a, thereby facilitating the deformation to be concentrated at the channel 121a, thereby reducing the force on the connection structure between the outer shell 11 and the top cover 12, and reducing the risk of cracking of the connection structure between the outer shell 11 and the top cover 12.

[0153] In some other embodiments, please refer to Figure 5 and Figure 6, the thickness of the connection between the shell 11 and the cover body 121 is L2, and the distance between the channel 121a and the shell 11 is L4, wherein 2L2≤L4≤4mm. That is, the distance between the channel 121a and the shell 11 is greater than or equal to 2 times the thickness of the connection between the shell 11 and the cover body 121, and less than or equal to 4 times the thickness of the connection between the shell 11 and the cover body 121.

[0154] In this embodiment, by setting the distance between the channel 121a and the outer shell 11 to 2L2-4mm, the top cover 12 can have sufficient strength, thereby improving the structural strength of the connection between the top cover 12 and the outer shell 11, and can further make the channel 121a on the top cover 12 as close to the outer shell 11 as possible, which is more conducive to the force at the connection between the outer shell 11 and the top cover 12 being transmitted to the channel 121a, thereby further facilitating the deformation to be concentrated at the channel 121a, and further reducing the force on the connection structure between the outer shell 11 and the top cover 12, thereby reducing the risk of cracking of the connection structure between the outer shell 11 and the top cover 12.

[0155] It should be noted that the width L1 of the channel, the thickness L2 of the connection between the outer shell and the cover body, the thickness L3 of the groove wall, the distance L4 between the channel and the outer shell, the dimension H of the cover body in the height direction of the outer shell and other values ​​can be tested and calculated by high-precision thickness gauges, vernier calipers and other instruments at room temperature when the top cover is not assembled.

[0156] The battery cell of the present application is further described below in conjunction with specific test examples.

[0157] The test sample of the embodiment of the present application: the top cover includes a cover body and a connecting piece, the cover body has a channel penetrating the cover body, and the connecting piece is arranged on a side of the cover body close to the electrode assembly and closes the channel.

[0158] By carrying out charge and discharge cycle experiments on the test samples of the embodiment of the present application and the control group, and recording the number of cycles, the number of cycles of the five test samples of the embodiment of the present application are 3263, 3351, 3374, 3410, and 3486, respectively, and the average number of cycles of the five test samples of the embodiment of the present application is 3376 times, and the number of cycles of the five test samples of the control group are 2415, 2577, 2634, 2680, and 2699, respectively, and the average number of cycles of the five test samples of the embodiment of the present application is 2601 times. When the electrode assembly cyclically expands and generates gas during charge and discharge, force is generated at the connection between the outer shell 11 and the top cover 12. The number of cycles of the battery cell 10 provided in the embodiment of the present application is much greater than that of the control group. That is to say, the battery cell 10 provided in the embodiment of the present application reduces the risk of cracking of the connection structure between the outer shell 11 and the top cover 12, improves the problem of failure of the connection structure between the outer shell 11 and the top cover 12, and increases the service life of the battery cell 10.

[0159] In the description of the present application, the description with reference to the terms "in one embodiment", "in some embodiments", "in other embodiments", "in yet other embodiments", or "exemplary" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present application, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. In addition, those skilled in the art may combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0160] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing having a receiving space and an opening; A top cover, a sealing cover is arranged at the opening; An electrode assembly is disposed in the accommodation space; The top cover includes a cover body and a connecting piece, the cover body has a channel penetrating the cover body, and the connecting piece is arranged on a side of the cover body close to the electrode assembly and closes the channel.

2. The battery cell according to claim 1, characterized in that: The channel extends along an edge of the cover body.

3. The battery cell according to claim 1, characterized in that: The connecting member is recessed toward a side away from the channel to form a groove, and the groove is communicated with the channel.

4. The battery cell according to claim 3, characterized in that: At least part of the side wall of the connecting member away from the channel side protrudes, so that the side wall of the connecting member corresponding to the channel side is recessed to form the groove; or, at least part of the side wall of the connecting member close to the channel side is thinned to form the groove.

5. The battery cell according to claim 3, characterized in that: In a cross section perpendicular to an extending direction of the channel, a cross-sectional shape of the groove is one of an arc shape, a U shape and a polygon shape.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The cover body is provided with a circle of the channels corresponding to the contour of the cover body.

7. The battery cell according to any one of claims 1 to 5, characterized in that: The cover body is rectangular, and at least one long side of the cover body is provided with the channel corresponding to the outline of the cover body.

8. The battery cell according to any one of claims 1 to 5, characterized in that: In a cross section perpendicular to the extension direction of the channel, the width of the channel is L1, wherein 0.5 mm ≤ L1 ≤ 10 mm.

9. The battery cell according to any one of claims 1 to 5, characterized in that: In a cross section perpendicular to the extension direction of the channel, the width of the channel is L1, wherein 0.8 mm ≤ L1 ≤ 3 mm.

10. The battery cell according to any one of claims 3 to 5, characterized in that: The thickness of the connection between the shell and the cover body is L2, and the thickness of the groove wall of the groove is L3, wherein L2≤L3≤4L2.

11. The battery cell according to any one of claims 3 to 5, characterized in that: The thickness of the connection between the shell and the cover body is L2, and the thickness of the groove wall of the groove is L3, wherein L2≤L3≤2L2.

12. The battery cell according to any one of claims 1 to 5, characterized in that: The distance between the channel and the housing is L4, wherein 1mm≤L4≤10mm.

13. The battery cell according to any one of claims 1 to 5, characterized in that: The thickness of the connection between the shell and the cover body is L2, and the distance between the channel and the shell is L4, wherein 2L2≤L4≤4mm.

14. The battery cell according to any one of claims 1 to 5, characterized in that: The dimension of the cover body in the height direction of the shell is H, wherein 1mm≤H≤5mm; and / or the thickness of the connection between the shell and the cover body is L2, wherein 0.4mm≤L2≤2mm.

15. The battery cell according to any one of claims 1 to 5, characterized in that: The dimension of the cover body in the height direction of the shell is H, wherein 1.5 mm ≤ H ≤ 3 mm; and / or the thickness of the connection between the shell and the cover body is L2, wherein 0.6 mm ≤ L2 ≤ 1.7 mm.

16. A battery, characterized in that: Comprising at least one battery cell according to any one of claims 1 to 15.

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

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