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 and an electrode assembly, the shell comprises a top cover and an outer shell with a containing space and an opening. And the top cover hermetically covers the opening. The electrode assembly is arranged in the accommodating space. The top cover is provided with a cover body and a connecting side wall. One end of the connecting side wall is connected with one side, facing the electrode assembly, of the cover body, and the other end extends in the direction away from the cover body. The shell is at least connected with the outer side wall of the connecting side wall. According to the battery monomer provided by the embodiment of the invention, the deformation capability of the top cover can be improved, 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 top cover to deform the top cover; the risk of fatigue cracking of the connecting structure between the shell and the top cover is reduced, the expansion resistance of the shell is improved, and the structural strength of the connecting position of the top cover and the shell can be improved.

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 is provided with a cover body and a connecting side wall, one end of the connecting side wall is connected to the side of the cover body facing the electrode assembly, and the other end extends in a direction away from the cover body, the outer shell is connected to at least the outer side wall of the connecting side wall, and the size of the cover body in the height direction of the outer shell is different from the thickness of the connecting side wall.

[0010] In the battery cell provided in the embodiment of the present application, the top cover is provided with a cover body and a connecting side wall, and the outer shell is at least connected to the outer side wall of the connecting side wall. This structure can improve the deformation capacity of the top cover. Therefore, when the electrode assembly expands cyclically and generates gas during charge and discharge, when a force is applied to the connection between the outer shell and the top cover, the force is easily transmitted to the top cover to deform 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, improving the expansion resistance of the shell, and improving the service life of the battery cell. In addition, the outer shell is at least connected to the outer side wall of the connecting side wall, which is conducive to increasing the contact area and connection area between the top cover and the outer shell, improving the shear resistance (also called shear strength) of the connection between the outer shell and the top cover, that is, improving the maximum stress value that the connection between the outer shell and the top cover can bear under the action of shear force, thereby improving the structural strength of the connection between the top cover and the outer shell.

[0011] In some embodiments, the wall thickness of the cover body is different from the wall thickness of the connecting side wall.

[0012] This is beneficial for deforming the area of ​​the top cover with a smaller wall thickness, thereby further improving the deformation capacity of the top cover, thereby further facilitating the force at the connection between the shell and the top cover to be transmitted to the top cover to deform the top cover.

[0013] In some embodiments, at least a portion of a connection between the cover body and the connecting side wall is thinned to form a deformation zone, and a minimum wall thickness of the deformation zone is smaller than the wall thickness of the cover body and the connecting side wall.

[0014] The force at the connection between the shell and the top cover is transferred to the deformation area of ​​the top cover to deform the deformation area. In addition, by controlling the deformation of the deformation area of ​​the top cover, the position of the deformation area of ​​the top cover can be controlled, which is conducive to improving the reliability and expansion resistance of the shell.

[0015] In some embodiments, along the height direction of the shell, the top end of the connecting side wall is higher than the top end of the shell, or the top end of the connecting side wall is flush with the top end of the shell.

[0016] In this embodiment, by setting the top of the connecting side wall to be higher than the top of the shell, it is beneficial for the force of the shell acting on the connecting side wall to form a torque, thereby facilitating the deformation of the top cover.

[0017] By setting the top of the connecting side wall to be flush with the top of the outer shell, the volume of the top cover exposed from the outer shell can be reduced as much as possible, thereby reducing the volume of the battery cell, improving the compactness of the battery, and facilitating the subsequent production steps of the battery cell, thereby improving the production efficiency of the battery cell.

[0018] In some embodiments, the deformation area is formed at the connection between the cover body and the connecting side wall.

[0019] The force at the connection between the outer shell and the top cover can be transmitted to the peripheral side of the top cover more evenly, thereby improving the uniformity of the deformation of the top cover, thereby further reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover.

[0020] In some embodiments, the battery cell is in a rectangular parallelepiped shape, and the deformation area is provided on at least one long side of the top cover.

[0021] While ensuring that 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 deformation area of ​​the top cover, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover.

[0022] In some embodiments, the battery cell is cylindrical in shape, and at least a portion of the top cover is provided with a deformation region.

[0023] While ensuring that 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 deformation area of ​​the top cover, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell and the top cover.

[0024] In some embodiments, the surface of the deformation region is a plane, or the surface of the deformation region is a curved surface.

[0025] In some embodiments, a dimension of the connecting side wall in a height direction of the housing is H1, wherein 1 mm ≤ H1 ≤ 10 mm.

[0026] In this embodiment, by setting the size of the connecting side wall in the height direction of the outer shell to 1mm-10mm, the connecting side wall and the outer shell can have sufficient contact area and connection area, thereby improving the structural strength of the connection between the top cover and the outer shell, and the top cover can have sufficient deformation ability while not protruding too much from the outer shell, thereby making the structure of the battery cell compact and reducing the volume of the battery cell as much as possible, thereby improving the performance of the battery.

[0027] In some embodiments, a dimension of the connecting side wall in a height direction of the housing is H1, wherein 2 mm ≤ H1 ≤ 7 mm.

[0028] In some embodiments, the thickness of the connection portion between the shell and the connecting side wall is L1, and the thickness of the connecting side wall in other regions except the deformation region is L2, wherein L1≤L2≤5 mm.

[0029] In this embodiment, by setting the thickness of the connecting side wall to L1-5mm, that is, setting the thickness of the connecting side wall to be greater than or equal to the thickness of the connection between the shell and the connecting side wall, the connecting side wall can have sufficient strength, thereby improving the structural strength of the connection between the top cover and the shell, and at the same time, the deformation area 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 deformation area, thereby facilitating the deformation to be concentrated in the deformation area, thereby reducing the force on the connection structure between the shell and the top cover, reducing the risk of cracking of the connection structure between the shell and the top cover, improving the problem of failure of the connection structure between the shell and the top cover, and increasing the service life of the battery cell.

[0030] In some embodiments, the thickness of the connection portion between the shell and the connecting side wall is L1, and the thickness of the connecting side wall other than the deformation region is L2, wherein L1≤L2≤3 mm.

[0031] In some embodiments, the thickness of the connection between the shell and the connecting side wall is L1, and the minimum wall thickness of the deformation area is L3, wherein 0.5L1≤L3≤2L1.

[0032] In this embodiment, by setting the minimum wall thickness of the deformation area to 0.5L1-2L1, 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 deformation area, which is more conducive to concentrating the deformation in the deformation area, 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.

[0033] In some embodiments, the thickness of the connection between the shell and the connecting side wall is L1, and the minimum wall thickness of the deformation area is L3, wherein L1-0.2mm≤L3≤1.5L1.

[0034] In some embodiments, the dimension of the cover body in the height direction of the shell is H2, wherein 1mm≤H2≤5mm; and / or the thickness of the connection between the shell and the connecting side wall is L1, wherein 0.4mm≤L1≤2mm.

[0035] 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.

[0036] In this embodiment, by setting the thickness of the connection between the shell and the connecting side wall 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.

[0037] In some embodiments, the dimension of the cover body in the height direction of the shell is H2, wherein 1.5 mm ≤ H2 ≤ 3 mm; and / or the thickness of the connection between the shell and the connecting side wall is L1, wherein 0.6 mm ≤ L1 ≤ 1.7 mm.

[0038] A second aspect of an embodiment of the present application provides a battery, comprising at least one battery cell as described above.

[0039] The battery provided by the embodiment of the present application includes at least one battery cell of the embodiment of the present application, the top cover is provided with a cover body and a connecting side wall, and the outer shell is at least connected to the outer side wall of the connecting side wall, and the structure can improve the deformation capacity of the top cover, thereby, when the electrode assembly cyclically expands and generates gas during charge and discharge, when a force is applied to the connection between the outer shell and the top cover, the force is more easily transmitted to the top cover to deform 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, improving the expansion resistance of the shell, and improving the service life of the battery cell. In addition, the outer shell is at least connected to the outer side wall of the connecting side wall, which is conducive to increasing the contact area and connection area between the top cover and the outer shell, improving the shear resistance (also called shear strength) of the connection between the outer shell and the top cover, that is, improving the maximum stress value that the connection between the outer shell and the top cover can bear under the action of shear force, thereby improving the structural strength of the connection between the top cover and the outer shell.

[0040] 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.

[0041] The electric device provided in the embodiment of the present application includes a battery, the battery includes at least one battery cell of the embodiment of the present application, the top cover is provided with a cover body and a connecting side wall, and the outer shell is at least connected to the outer side wall of the connecting side wall, and the structure can improve the deformation capacity of the top cover, thereby, when the electrode assembly cyclically expands and generates gas during charge and discharge, when a force is applied to the connection between the outer shell and the top cover, the force is more easily transmitted to the top cover to deform 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, improving the expansion resistance of the shell, and improving the service life of the battery cell. In addition, the outer shell is at least connected to the outer side wall of the connecting side wall, which is conducive to increasing the contact area and connection area between the top cover and the outer shell, improving the shear resistance (also called shear strength) of the connection between the outer shell and the top cover, that is, improving the maximum stress value that the connection between the outer shell and the top cover can bear under the action of shear force, thereby improving the structural strength of the connection between the top cover and the outer shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 A schematic diagram of the structure of a vehicle provided in one embodiment of the present application;

[0043] Figure 2 A three-dimensional exploded schematic diagram of a battery provided in one embodiment of the present application;

[0044] Figure 3 A top view of a battery cell provided in one embodiment of the present application;

[0045] Figure 4 An exploded view of a battery cell provided in an embodiment of the present application, wherein the electrode assembly is omitted;

[0046] Figure 5 for Figure 3 Section view in AA direction;

[0047] Figure 6 for Figure 5 The enlarged view of point B in the middle;

[0048] 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;

[0049] 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.

[0050] Description of Reference Numerals

[0051] 10. Battery cell; 11. Shell; 11a. Accommodation space; 11b. Opening; 12. Top cover; 12a. Deformation area; 121. Cover body; 122. Connecting side wall; 20. Battery box; 21. First box body; 22. Second box body; 100. Battery; 200. Controller; 300. Motor; 1000. Vehicle. DETAILED DESCRIPTION

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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).

[0065] 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.

[0066] 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.

[0067] In order to improve the problem of failure of the connection structure between the 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 a shell and an electrode assembly. The shell includes a top cover and a shell having 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 is provided with a cover body and a connecting side wall. One end of the connecting side wall is connected to a side of the cover body facing the electrode assembly, and the other end extends in a direction away from the cover body. The shell is connected to at least the outer side wall of the connecting side wall.

[0068] In the battery cell provided in the embodiment of the present application, the top cover is provided with a cover body and a connecting side wall, and the outer shell is at least connected to the outer side wall of the connecting side wall. This structure can improve the deformation capacity of the top cover. Therefore, when the electrode assembly expands cyclically and generates gas during charge and discharge, when a force is applied to the connection between the outer shell and the top cover, the force is easily transmitted to the top cover to deform 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, improving the expansion resistance of the shell, and improving the service life of the battery cell. In addition, the outer shell is at least connected to the outer side wall of the connecting side wall, which is conducive to increasing the contact area and connection area between the top cover and the outer shell, improving the shear resistance (also called shear strength) of the connection between the outer shell and the top cover, that is, improving the maximum stress value that the connection between the outer shell and the top cover can bear under the action of shear force, thereby improving the structural strength of the connection between the top cover and the outer shell.

[0069] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] Please refer to Figure 1 , Figure 1 A 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.

[0074] 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.

[0075] 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 .

[0076] 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.

[0077] 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 an opening 11b at one end, the first box body 21 is a plate-like structure, and the first box body 21 covers the opening 11b 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 an opening 11b at one side, and the opening 11b side of the first box body 21 covers the opening 11b 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.

[0078] 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 .

[0079] 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.

[0080] 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.

[0081] 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.

[0082] The present application embodiment provides a battery cell 10. Figures 3 to 6 The battery cell 10 includes a shell and an electrode assembly. The shell includes a top cover 12 and a shell 11 having 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. Among them, the top cover 12 is provided with a cover body 121 and a connecting side wall 122. One end of the connecting side wall 122 is connected to a side of the cover body 121 facing the electrode assembly, and the other end extends in a direction away from the cover body 121. The shell 11 is connected to at least the outer side wall of the connecting side wall 122.

[0083] Here, the housing may be in a cylindrical, flat, rectangular or other shapes.

[0084] It should be noted that the height direction of the housing 11 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.

[0085] 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.

[0086] Exemplarily, the cover body 121 and the connecting side wall 122 are an integrated structure. The integrated cover body 121 and the connecting side wall 122 can reduce the number of parts, reduce assembly time, and improve assembly efficiency and structural strength.

[0087] Of course, the cover body 121 and the connecting side wall 122 may also be a split structure, for example, the connecting side wall 122 is welded to the side of the cover body 121 close to the electrode assembly. The split cover body 121 and the connecting side wall 122 are conducive to molding.

[0088] The outer shell 11 is connected to at least the outer side wall of the connecting side wall 122 , which means that the outer shell 11 may only be connected to the outer side wall of the connecting side wall 122 . Of course, the outer shell 11 may also be connected to the outer side wall of the cover body 121 .

[0089] Exemplarily, at least a portion of the connecting side wall 122 extends into the accommodating space 11 a through the opening 11 b , and then the outer side wall of the connecting side wall 122 is connected to the outer shell 11 .

[0090] Here, the top cover 12 is provided with a cover body 121 and a connecting side wall 122. On the one hand, the outer shell 11 is connected to the outer side wall of the connecting side wall 122. When a force is applied to the connection between the outer shell 11 and the top cover 12, a moment can be formed on the connecting side wall 122, so that the connecting side wall 122 or the cover body 121 can be deformed (see Figure 7 ), that is, when the electrode assembly expands cyclically and generates gas during charge and discharge, the force is more easily transmitted to the top cover 12 to deform the connecting side wall 122. On the other hand, the shell 11 is connected to the connecting side wall 122 and the outer wall of the cover body 121 at the same time, which is conducive to increasing the contact area and connection area between the top cover 12 and the shell 11, and improving the shear resistance (also called shear strength) of the connection between the shell 11 and the top cover 12, that is, improving the maximum stress value that the connection between the shell 11 and the top cover 12 can bear under the action of shear force, thereby improving the structural strength of the connection between the top cover 12 and the shell 11, and reducing the risk of fatigue cracking of the connection structure between the shell 11 and the top cover 12.

[0091] The top cover 12 is generally perpendicular to the side of the outer shell 11, and the outer shell 11 is deformed 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 the charge and discharge process, a force is exerted on the outer shell 11, which can cause the connecting side wall 122 or the cover body 121 to deform, 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 increasing the service life of the battery cell 10.

[0092] In the battery cell 10 provided in the embodiment of the present application, the top cover 12 is provided with a cover body 121 and a connecting side wall 122, and the outer shell 11 is connected to at least the outer side wall of the connecting side wall 122. This structure can improve the deformation ability of the top cover 12. Therefore, when the electrode assembly cyclically expands and generates gas during charging and discharging, when a force is applied to the connection between the outer shell 11 and the top cover 12, the force is more easily transmitted to the top cover 12 to cause the top cover 12 to deform, thereby reducing the stress 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, improving the expansion resistance of the shell, and increasing the service life of the battery cell 10. In addition, the outer shell 11 is connected to at least the outer side wall of the connecting side wall 122, which is beneficial to increase the contact area and connection area between the top cover 12 and the outer shell 11, and improve the shear resistance (also called shear strength) of the connection between the outer shell 11 and the top cover 12, that is, improve the maximum stress value that the connection between the outer shell 11 and the top cover 12 can bear under the action of shear force, thereby improving the structural strength of the connection between the top cover 12 and the outer shell 11.

[0093] For some examples, see Figure 6 , the wall thickness of the cover body 121 is different from the wall thickness of the connecting side wall 122.

[0094] Here, the wall thickness of the cover body 121 refers to the size of the cover body 121 in the height direction of the housing 11, that is, the thickness of the cover body 121 in the height direction of the housing 11 is different from the thickness of the connecting side wall 122. Figure 6 H2 shown.

[0095] The wall thickness of the cover body 121 is different from the wall thickness of the connecting side wall 122 , which means that the wall thickness of the cover body 121 may be greater than the wall thickness of the connecting side wall 122 , or the wall thickness of the cover body 121 may be less than the wall thickness of the connecting side wall 122 .

[0096] In this embodiment, by setting the wall thickness of the cover body 121 and the connecting side wall 122 to be different, it is beneficial to cause the area of ​​the top cover 12 with smaller wall thickness to deform, thereby further improving the deformation capacity of the top cover 12, which is further beneficial to further transmit the force at the connection between the outer shell 11 and the top cover 12 to the top cover 12 to cause the top cover 12 to deform.

[0097] For some examples, see Figure 4 and Figure 6 At least a portion of the connection between the cover body 121 and the connecting side wall 122 is thinned to form a deformation area 12a, and the minimum wall thickness of the deformation area 12a is smaller than the wall thickness of the cover body 121 and the connecting side wall 122.

[0098] The connection point between the cover body 121 and the connecting side wall 122 is the corner of the top cover 12 .

[0099] The minimum wall thickness of the deformation area 12a is smaller than the wall thickness of the cover body 121 and the connecting side wall 122, that is, it is conducive to transmitting the force at the connection between the shell 11 and the top cover 12 to the deformation area 12a of the top cover 12 to deform the deformation area 12a.

[0100] In this embodiment, by thinning the connection between the cover body 121 and the connecting side wall 122, the strength of the connection between the cover body 121 and the connecting side wall 122 can be weakened to form a deformation area 12a, which is further conducive to the force of the connection between the shell 11 and the top cover 12 being transmitted to the deformation area 12a of the top cover 12 to deform the deformation area 12a, thereby further reducing the risk of fatigue cracking of the connection structure between the shell 11 and the top cover 12. In addition, by controlling the deformation of the deformation area 12a of the top cover 12, the position of the deformation area 12a of the top cover 12 can be controlled, which is conducive to improving the reliability and expansion resistance of the shell.

[0101] It should be noted that at least part of the connection between the cover body 121 and the connecting side wall 122 is thinned to form the deformation area 12a, which means that part of the connection between the cover body 121 and the connecting side wall 122 can be thinned to form the deformation area 12a, or the entire connection between the cover body 121 and the connecting side wall 122 can be thinned to form the deformation area 12a, that is, the connection between the cover body 121 and the connecting side wall 122 is formed with a deformation area 12a, that is, the top cover 12 is provided with a circle of deformation area 12a.

[0102] Exemplarily, the battery cell 10 is cylindrical, and the deformation area 12a is provided on at least part of the top cover 12. That is, the top cover 12 may be provided with a circle of deformation areas 12a, or may be partially surrounded by deformation areas 12a.

[0103] When the top cover 12 is in a rectangular shape, the deformation area 12a may be formed partially or entirely on the long side, or partially or entirely on the short side. In some embodiments, the top cover 12 is provided with a circle of deformation areas 12a.

[0104] Here, by forming a deformation area 12a at the connection between the cover body 121 and the connecting side wall 122, a circle of deformation area 12a with weaker strength can be formed on the surrounding side of the top cover 12. As a result, the force at the connection between the outer shell 11 and the top cover 12 can be transmitted more evenly to the surrounding side of the top cover 12, thereby improving the uniformity of the deformation of the top cover 12, thereby further reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12.

[0105] In some other embodiments, please refer to Figure 4 The battery cell 10 is in a rectangular shape, and at least one long side of the top cover 12 is provided with a deformation area 12a, that is, the top cover 12 can have one long side corresponding to the deformation area 12a, or two long sides corresponding to the deformation area 12a, while the two short sides have no corresponding deformation area 12a.

[0106] In this embodiment, by providing a deformation area 12a on at least one long side of the top cover 12, 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 deformation area 12a of the top cover 12, thereby reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12.

[0107] For some examples, see Figure 6 , along the height direction of the shell 11 , the top of the connecting side wall 122 is higher than the top of the shell 11 .

[0108] The top of the connecting side wall 122 is higher than the top of the shell 11 , that is, the shell 11 is only connected to a portion of the outer wall of the connecting side wall 122 , and another portion of the connecting side wall 122 is located outside the shell 11 , that is, exposed to the shell 11 .

[0109] In this embodiment, by setting the top of the connecting side wall 122 to be higher than the top of the shell 11 , the force exerted by the shell 11 on the connecting side wall 122 is conducive to forming a torque, thereby facilitating the deformation of the top cover 12 .

[0110] In some embodiments, along the height direction of the housing 11 , the top end of the connecting side wall 122 is flush with the top end of the housing 11 .

[0111] The top of the connecting side wall 122 is flush with the top of the housing 11 , that is, the top of the connecting side wall 122 and the top of the housing 11 are located in the same plane.

[0112] In this embodiment, by setting the top end of the connecting side wall 122 to be flush with the top end of the outer shell 11, the volume of the top cover 12 exposed from the outer shell 11 can be reduced as much as possible, thereby reducing the volume of the battery cell 10, improving the compactness of the battery 100, and facilitating the subsequent production steps of the battery cell 10, thereby improving the production efficiency of the battery cell 10.

[0113] Of course, in other embodiments, along the height direction of the housing 11 , the top of the connecting side wall 122 may also be lower than the top of the housing 11 .

[0114] It should be noted that the surface shape of the deformation region 12a is not limited here.

[0115] For some examples, see Figure 6 , the surface of the deformation area 12a is a plane.

[0116] Here, the connection between the cover body 121 of the top cover 12 and the connecting side wall 122 may be beveled, and the beveled cut surface is the deformation area 12a, or the connection between the cover body 121 of the top cover 12 and the connecting side wall 122 may be chamfered, and the chamfered area is the deformation area 12a.

[0117] It should be noted that the surface of the deformation area 12 a may be partially formed on the cover body 121 , and another part formed on the connecting side wall 122 , or may be entirely formed on the cover body 121 .

[0118] In some other embodiments, the surface of the deformation region 12a is a curved surface.

[0119] Here, the curved surface may be an inwardly concave curved surface or an outwardly convex curved surface.

[0120] 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 H2, wherein 1mm≤H2≤5mm, for example, 1mm, 1.3mm, 1.4mm, 1.5mm, 1.7mm, 2mm, 3mm, 3.4mm, 3.5mm, 3.7mm, 4mm, 4.3mm, 4.5mm, 4.7mm or 5mm, etc.

[0121] The dimension of the cover body 121 in the height direction of the housing 11 refers to the wall thickness of the cover body 121 .

[0122] 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.

[0123] In some other embodiments, please refer to Figure 5 and Figure 6 The dimension of the cover body 121 in the height direction of the housing 11 is H2, wherein 1.5 mm ≤ H2 ≤ 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.

[0124] 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.

[0125] In some embodiments, please refer to Figure 5 and Figure 6 The thickness of the connection between the housing 11 and the connecting side wall 122 is L1, wherein 0.4 mm ≤ L1 ≤ 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.

[0126] The thickness of the connection between the shell 11 and the connecting side wall 122 is L2, that is, the thickness of the shell 11 near the opening 11b is L2.

[0127] 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.

[0128] 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.

[0129] 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.

[0130] In this embodiment, by setting the thickness of the connection between the outer shell 11 and the connecting side wall 122 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.

[0131] For other embodiments, please refer to Figure 5 and Figure 6 The thickness of the connection between the housing 11 and the connecting side wall 122 is L1, wherein 0.6 mm ≤ L1 ≤ 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, etc.

[0132] In this embodiment, by setting the thickness of the connection between the outer shell 11 and the connecting side wall 122 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.

[0133] In some embodiments, please refer to Figure 6 and Figure 7 , the dimension of the connecting side wall 122 in the height direction of the housing 11 is H1, wherein 1mm≤H1≤10mm, for example, 1mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 2mm, 3mm, 3.5mm, 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.3mm, 8.5mm, 8.6mm, 9.9mm, 9mm, 9.2mm, 9.4mm, 9.7mm, 9.9mm or 10mm, etc.

[0134] In this embodiment, by setting the dimension of the connecting side wall 122 in the height direction of the outer shell 11 to 1mm-10mm, the connecting side wall 122 and the outer shell 11 can have sufficient contact area and connection area, thereby improving the structural strength of the connection between the top cover 12 and the outer shell 11, and while the top cover 12 has sufficient deformation ability, it can also be made that the top cover 12 does not protrude too much from the outer shell 11, thereby making the structure of the battery cell 10 compact and reducing the volume of the battery cell 10 as much as possible, thereby improving the performance of the battery 100.

[0135] In some other embodiments, please refer to Figure 6 and Figure 7 , the dimension of the connecting side wall 122 in the height direction of the housing 11 is H1, wherein 2mm≤H1≤7mm, for example, 2mm, 2.3mm, 2.4mm, 2.5mm, 2.7mm, 2.9mm, 3mm, 3.4mm, 3.5mm, 3.7mm, 4mm, 4.3mm, 4.5mm, 4.7mm, 5mm, 5.4mm, 5.5mm, 5.8mm, 6mm, 6.3mm, 6.6mm, 6.9mm or 7mm, etc.

[0136] In this embodiment, by setting the size of the connecting side wall 122 in the height direction of the outer shell 11 to 2mm-7mm, the structural strength of the connection between the top cover 12 and the outer shell 11 can be further improved, and the top cover 12 can have sufficient deformation ability. At the same time, the structure of the battery cell 10 can be further made compact, and the volume of the battery cell 10 can be further reduced, thereby improving the performance of the battery 100.

[0137] In some embodiments, see Figure 6 and Figure 7 The thickness of the connection between the shell 11 and the connecting side wall 122 is L1, and the thickness of the connecting side wall 122 other than the deformation area 12a is L2, wherein L1≤L2≤5mm. In other words, the thickness of the connecting side wall 122 is greater than or equal to the thickness of the connection between the shell 11 and the connecting side wall 122, and less than or equal to 5mm.

[0138] Here, the thickness of the connection between the housing 11 and the connecting side wall 122 is the wall thickness of the first region.

[0139] In this embodiment, by setting the thickness of the connecting side wall 122 to L1-5mm, that is, setting the thickness of the connecting side wall 122 to be greater than or equal to the thickness of the connection between the outer shell 11 and the connecting side wall 122, the connecting side wall 122 can have sufficient strength, thereby improving the structural strength of the connection between the top cover 12 and the outer shell 11, and at the same time, the deformation area 12a 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 deformation area 12a, thereby facilitating the deformation to be concentrated in the deformation area 12a, 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, 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.

[0140] In some other embodiments, please refer to Figure 6 and Figure 7The thickness of the connection between the shell 11 and the connecting side wall 122 is L1, and the thickness of the connecting side wall 122 other than the deformation area 12a is L2, wherein L1≤L2≤3mm. In other words, the thickness of the connecting side wall 122 is greater than or equal to the thickness of the connection between the shell 11 and the connecting side wall 122, and less than or equal to 3mm.

[0141] In this embodiment, by setting the thickness of the connecting side wall 122 to L1-3mm, the connecting side wall 122 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 deformation area 12a on the top cover 12 close to the outer shell 11, which is further beneficial to the force transmission of the connection between the outer shell 11 and the top cover 12 to the deformation area 12a, thereby reducing the risk of cracking of the connection structure between the outer shell 11 and the top cover 12.

[0142] In some embodiments, see Figure 6 and Figure 7 , the thickness of the connection between the shell 11 and the connecting side wall 122 is L1, and the minimum wall thickness of the deformation area 12a is L3, wherein 0.5L1≤L3≤2L1. In other words, the minimum wall thickness of the deformation area 12a is L3 which is greater than or equal to 0.5 times the thickness of the connection between the shell 11 and the connecting side wall 122, and less than or equal to 2 times the thickness of the connection between the shell 11 and the connecting side wall 122.

[0143] L3 is, for example, 0.5L1, 0.6L1, 0.7L1, 0.8L1, 1L1, 1.1L1, 1.2L1, 1.4L1, 1.5L1, 1.6L1, 1.7L1, 1.8L1, 1.9L1 or 2L1, etc.

[0144] It can be understood that the smaller the minimum wall thickness of the deformation area 12a, 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 deformation area 12a, that is, it is more conducive to concentrating the deformation in the deformation area 12a, but it will affect the structural strength of the top cover 12 in the deformation area 12a.

[0145] In this embodiment, by setting the minimum wall thickness of the deformation area 12a to 0.5L1-2L1, the top cover 12 can have sufficient strength, and it can also be beneficial for the force at the connection between the outer shell 11 and the top cover 12 to be transferred to the deformation area 12a, which is more conducive to concentrating the deformation in the deformation area 12a, 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.

[0146] In some other embodiments, please refer to Figure 5 and Figure 6, the thickness of the connection between the shell 11 and the connecting side wall 122 is L1, and the minimum wall thickness of the deformation area 12a is L3, wherein L1-0.2mm≤L3≤1.5L1. In other words, the minimum wall thickness of the deformation area 12a is L3 which is greater than or equal to the thickness of the connection between the shell 11 and the connecting side wall 122 minus 0.2mm, and less than or equal to 1.5 times the thickness of the connection between the shell 11 and the connecting side wall 122.

[0147] L3 is, for example, L1-0.2mm, L1-0.1mm, 1L1, 1.1L1, 1.2L1, 1.4L1 or 1.5L1, etc.

[0148] In this embodiment, by setting the minimum wall thickness of the deformation area 12a to L1-0.2mm≤L3≤1.5L1, the force at the connection between the outer shell 11 and the top cover 12 can be transferred to the deformation area 12a, which helps to concentrate the deformation in the deformation area 12a. 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.

[0149] It should be noted that the dimension H1 of the connecting side wall in the height direction of the shell, the dimension H2 of the cover body in the height direction of the shell, the thickness L1 at the connection between the shell and the connecting side wall, the thickness L2 of the connecting side wall other than the deformation area, the minimum wall thickness L3 of the deformation area and other values ​​can be obtained by testing and calculation through high-precision thickness gauges, vernier calipers and other instruments at normal temperature when the top cover is not assembled.

[0150] The battery cell of the present application is further described below in conjunction with specific test examples.

[0151] The test sample of the embodiment of the present application: the top cover is provided with a cover body and a connecting side wall, one end of the connecting side wall is connected to the side of the cover body facing the electrode assembly, and the other end extends in a direction away from the cover body, and the outer shell is connected to at least the outer side wall of the connecting side wall. At least a part of the area where the cover body and the connecting side wall are connected is thinned to form a deformation area, and the minimum wall thickness of the deformation area is less than the wall thickness of the cover body and the connecting side wall.

[0152] 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 3174, 3192, 3241, 3266, and 3308, respectively, and the average number of cycles of the five test samples of the embodiment of the present application is 3236 times, and the number of cycles of the five test samples of the control group are 2690, 2732, 2788, 2805, and 2810, respectively, and the average number of cycles of the five test samples of the embodiment of the present application is 2765 times. When the electrode assembly cyclically expands and gas is generated 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.

[0153] 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.

[0154] 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: The housing comprises a top cover and a shell having a containing space and an opening, wherein the top cover sealing cover is arranged at the opening; An electrode assembly is disposed in the accommodation space; Among them, the top cover is provided with a cover body and a connecting side wall, one end of the connecting side wall is connected to the side of the cover body facing the electrode assembly, and the other end extends away from the cover body, and the outer shell is connected to at least the outer side wall of the connecting side wall.

2. The battery cell according to claim 1, characterized in that: The wall thickness of the cover body is different from the wall thickness of the connecting side wall.

3. The battery cell according to claim 1, characterized in that: At least a portion of the connection between the cover body and the connecting side wall is thinned to form a deformation area, and the minimum wall thickness of the deformation area is smaller than the wall thickness of the cover body and the connecting side wall.

4. The battery cell according to claim 3, characterized in that: The deformation area is formed at the connection between the cover body and the connection side wall.

5. The battery cell according to claim 3, characterized in that: The battery cell is in a rectangular parallelepiped shape, and at least one long side of the top cover is provided with the deformation area; or, The battery cell is cylindrical in shape, and the deformation area is provided on at least a portion of the top cover.

6. The battery cell according to claim 3, characterized in that: The surface of the deformation area is a plane, or the surface of the deformation area is a curved surface.

7. The battery cell according to any one of claims 1 to 6, characterized in that: Along the height direction of the shell, the top end of the connecting side wall is higher than the top end of the shell, or the top end of the connecting side wall is flush with the top end of the shell.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The dimension of the connecting side wall in the height direction of the housing is H1, wherein 1 mm ≤ H1 ≤ 10 mm.

9. The battery cell according to any one of claims 1 to 6, characterized in that: The dimension of the connecting side wall in the height direction of the housing is H1, wherein 2mm≤H1≤7mm.

10. The battery cell according to any one of claims 3 to 6, characterized in that: The thickness of the connection between the shell and the connecting side wall is L1, and the thickness of the connecting side wall in other areas except the deformation area is L2, wherein L1≤L2≤5mm.

11. The battery cell according to any one of claims 3 to 6, characterized in that: The thickness of the connection between the shell and the connecting side wall is L1, and the thickness of the connecting side wall in other areas except the deformation area is L2, wherein L1≤L2≤3mm.

12. The battery cell according to any one of claims 3 to 6, characterized in that: The thickness of the connection between the shell and the connecting side wall is L1, and the minimum wall thickness of the deformation area is L3, wherein 0.5L1≤L3≤2L1.

13. The battery cell according to any one of claims 3 to 6, characterized in that: The thickness of the connection between the shell and the connecting side wall is L1, and the minimum wall thickness of the deformation area is L3, wherein L1-0.2mm≤L3≤1.5L1.

14. The battery cell according to any one of claims 1 to 6, characterized in that: The dimension of the cover body in the height direction of the shell is H2, wherein 1mm≤H2≤5mm; and / or the thickness of the connection between the shell and the connecting side wall is L1, wherein 0.4mm≤L1≤2mm.

15. The battery cell according to any one of claims 1 to 6, characterized in that: The dimension of the cover body in the height direction of the shell is H2, wherein 1.5 mm ≤ H2 ≤ 3 mm; and / or the thickness of the connection between the shell and the connecting side wall is L1, wherein 0.6 mm ≤ L1 ≤ 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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