Battery cell, battery, and electrical apparatus

Abstract

The embodiments of the present application provide a battery cell, a battery, and an electrical apparatus. The battery cell comprises a housing, a top cover, and an electrode assembly. The housing is provided with an accommodating space and an opening. The top cover seals and covers the opening. The electrode assembly is arranged within the accommodating space. The top cover comprises a cover body, a connecting side wall and a groove formed between the cover body and the connecting side wall, and an end portion of the housing extends into the groove and is connected with the top cover. When the electrode assembly expands cyclically and produces gas during charging and discharging, the housing deforms outwards when force is produced at the connection between the housing and the top cover, and the connecting side wall limits and supports the housing, so as to limit further outward deformation of the housing to a certain extent, thereby reducing the risk of fatigue cracking of the connecting structure between the housing and the top cover, improving the problem of failure of the connecting structure between the housing and the top cover, and increasing the service life of the battery cell.

Description

Battery monomer, battery and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of battery, in particular to a battery monomer, a battery and an electric device. BACKGROUND

[0002] This section is intended to provide background or context to the embodiments of the application. The description herein does not constitute admission that the information provided herein is prior art.

[0003] In the production process of the battery, after the bare battery cell is put into the shell and the top cover is closed, the battery cell with shell can be obtained. After the bare battery cell is put into the shell, shell cover welding needs to be performed to weld the shell and the top cover together. In the related art, when the bare battery cell circulates and expands and gas is generated during charging and discharging, the connection between the shell and the top cover will crack, and there is a problem of causing the connection structure between the shell and the top cover to fail.

[0004] SUMMARY

[0005] Therefore, the embodiments of the present application aim to provide a battery monomer, a battery and an electric device, which can improve the problem of the connection structure between the shell and the top cover failing, and improve the service life of the battery monomer.

[0006] To achieve the above-mentioned purpose, a first aspect of the embodiments of the present application provides a battery monomer, comprising:

[0007] a shell having a containing space and an opening;

[0008] a top cover, a sealing cover of which is arranged at the opening;

[0009] an electrode assembly arranged in the containing space;

[0010] The top cover comprises a cover body, a connecting side wall and a groove formed between the cover body and the connecting side wall, and the end of the shell extends into the groove and is connected with the top cover.

[0011] The battery monomer provided by the embodiments of the present application has the sealing cover of the top cover arranged at the opening of the shell. The top cover is arranged to comprise a cover body and a connecting side wall, and a groove is formed between the cover body and the connecting side wall. When assembled, the end of the shell extends into the groove and is connected with the top cover. Therefore, when the electrode assembly circulates and expands and gas is generated during charging and discharging, the connection between the shell and the top cover is subjected to the action of force, the shell will deform outwardly, and the connecting side wall will limit and support the shell, so as to limit the continuous deformation of the shell to a certain extent, reduce the risk of fatigue cracking of the connection structure between the shell and the top cover, improve the problem of the connection structure between the shell and the top cover failing, and improve the service life of the battery monomer.

[0012] In some embodiments, the shell comprises a body section and a connecting section connected to the body section, the connecting section extends into the recess and is connected to the top cover, and the distance between the connecting section and the central axis of the battery cell is less than the distance between the body section and the central axis of the battery cell.

[0013] By setting the distance between the connecting section and the central axis of the battery cell to be less than the distance between the body section and the central axis of the battery cell, the body section is expanded outward as much as possible while achieving the extension of the connecting section into the recess and the connection to the top cover, thereby increasing the size of the accommodation space and further improving the energy density of the battery cell.

[0014] In some embodiments, the shell comprises a transition section, the body section and the connecting section are connected through the transition section, the plane where the body section is located is parallel to the plane where the connecting section is located, and along the direction from the body section to the connecting section, the distance between the transition section and the central axis of the battery cell gradually decreases.

[0015] By setting the transition section, along the direction from the body section to the connecting section, the distance between the transition section and the central axis of the battery cell gradually decreases, thereby increasing the size of the accommodation space as much as possible and further improving the energy density of the battery cell.

[0016] In some embodiments, the height of the top cover at the recess is H1, wherein 0.2mm≤H1≤1.5mm.

[0017] By setting the height of the top cover at the recess to be 0.2mm-1.5mm, the height of the top cover at the recess can satisfy the penetration welding between the top cover and the end of the shell, and the top cover at the recess can also have sufficient structural strength.

[0018] In some embodiments, the height of the top cover at the recess is H1, wherein 0.3mm≤H1≤1mm.

[0019] By setting the height of the top cover at the recess to be 0.3mm-1mm, the penetration welding between the top cover and the end of the shell can be facilitated, and the top cover at the recess can further have sufficient structural strength.

[0020] In some embodiments, in a cross section perpendicular to the extension direction of the recess, the width of the recess is L1, wherein 0.4mm≤L1≤3.5mm.

[0021] By setting the width of the groove to 0.4mm-3.5mm, the end of the shell is facilitated to extend into the groove, and the welding area of the end of the shell and the groove wall is facilitated to increase, so as to improve the strength of the connecting structure between the shell and the top cover, reduce the risk of cracking of the connecting structure between the shell and the top cover, and improve the service life of the battery monomer.

[0022] In some embodiments, in a cross section perpendicular to the extension direction of the groove, the width of the groove is L1, wherein 0.6mm≤L1≤1mm.

[0023] By setting the width of the groove to 0.6mm-1mm, the connecting structure of the shell and the top cover can have sufficient strength while facilitating the manufacturing of the shell and the top cover.

[0024] In some embodiments, the height of the connecting side wall is H2, and the height of the cover body is H, wherein H-0.5mm≤H2≤13mm.

[0025] The connecting side wall in this height range can make the connecting side wall have sufficient contact area with the shell. When the electrode assembly cyclically swells and gas is generated during charging and discharging, the connecting side wall can sufficiently limit and support the shell, so as to limit the deformation of the shell to a certain extent, reduce the risk of fatigue cracking of the connecting structure between the shell and the top cover, improve the failure problem of the connecting structure between the shell and the top cover, and improve the service life of the battery monomer.

[0026] In some embodiments, the height of the connecting side wall is H2, and the height of the cover body is H, wherein H≤H2≤11mm.

[0027] In some embodiments, the thickness of the connecting side wall is L2, wherein 0.2mm≤L2≤1.5mm.

[0028] In this embodiment, by setting the thickness of the connecting side wall to 0.2mm-1.5mm, the connecting side wall can have sufficient strength, so as to improve the structural strength of the connecting portion of the top cover and the shell while minimizing the volume of the top cover, thereby improving the energy density of the battery monomer.

[0029] In some embodiments, the thickness of the connecting section is L3, wherein 0.3mm≤L3≤3mm; or,

[0030] In a cross section perpendicular to the extension direction of the groove, the width of the groove is L1, and the thickness of the connecting section is L3, wherein 0≤L1-L3≤0.3mm.

[0031] By setting the thickness of the connecting section to 0.3mm-3mm, the connecting section can have sufficient strength, thereby improving the structural strength of the connection between the top cover and the shell while minimizing the volume of the top cover and the shell as much as possible, thereby improving the energy density of the battery monomer.

[0032] By setting the difference between L1-L3 to 0-0.3mm, on the one hand, the shell can extend into the groove, and on the other hand, when the shell deforms outward, the connecting side wall can limit and support the shell, i.e., it is beneficial to reduce the deformation of the shell or the degree of deformation.

[0033] In some embodiments, the outer side wall of the shell forms a stepped surface facing the top cover, and the end of the connecting side wall abuts the stepped surface.

[0034] Here, on the one hand, the stepped surface can position the top cover, and together with the end surface of the shell, it can form a double positioning effect on the top cover, which is beneficial to improve the deformation of the top cover, and on the other hand, it is also beneficial to increase the structural strength of the shell at the stepped surface.

[0035] In some embodiments, the size of the stepped surface in the thickness direction of the shell is L4, where 0.1mm≤L4≤0.5mm.

[0036] By setting the size of the stepped surface in the thickness direction of the shell to 0.1mm-0.5mm, the positioning of the top cover can be achieved while minimizing the volume of the shell and the material for forming, which is beneficial to reduce costs and improve the energy density of the battery monomer.

[0037] In some embodiments, the groove extends along the edge of the top cover.

[0038] In this way, the stress near the groove can be more uniform.

[0039] In some embodiments, the battery monomer is a cuboid, and at least one long side of the top cover is provided with the groove; or,

[0040] When the battery monomer is rectangular, the top cover and the shell are more likely to deform outward and crack at the large surface, i.e., the connection structure between the long side of the top cover and the shell fails. Therefore, by providing a groove on the long side of the top cover, the problem of connection structure failure between the top cover and the shell can be effectively improved.

[0041] The battery monomer is a cylinder, and at least part of the area of the top cover is provided with the groove.

[0042] When the battery monomer is cylindrical, the top cover can be provided with a groove extending along the edge of the top cover, or can be partially surrounded by a groove.

[0043] In some embodiments, the material of the top cover and / or the shell is aluminum.

[0044] In some embodiments, the height of the cover body is H, wherein 1mm≤H≤5mm.

[0045] By setting the height of the cover body to 1mm-5mm, the top cover 12 has sufficient strength to protect the electrode assembly in the accommodation space, while reducing the weight and volume of the battery monomer, reducing the material of the top cover, reducing the cost, and improving the overall performance of the battery.

[0046] In some embodiments, the height of the cover body is H, wherein 1.5mm≤H≤3mm.

[0047] The second aspect of the embodiments of the present application provides a battery comprising at least one battery monomer as described above.

[0048] The battery provided by the embodiments of the present application comprises at least one battery monomer of the embodiments of the present application, and the top cover sealing cover is arranged at the opening of the shell. By setting the top cover to comprise a cover body and a connecting side wall and forming a groove between the cover body and the connecting side wall, during assembly, the end of the shell can be inserted into the groove and connected with the top cover. Thus, when the electrode assembly cyclically expands and generates gas during charging and discharging, the force acting on the connecting portion of the shell and the top cover causes the shell to deform outwardly, and the connecting side wall supports and limits the shell, thereby limiting the deformation of the shell to a certain extent, reducing the risk of fatigue cracking of the connecting structure between the shell and the top cover, improving the failure of the connecting structure between the shell and the top cover, and prolonging the service life of the battery monomer.

[0049] The third aspect of the embodiments of the present application provides a power consuming device comprising the battery as described above, wherein the battery is used to provide electric energy for the power consuming device.

[0050] The power consuming device provided by the embodiments of the present application comprises a battery, and the top cover sealing cover is arranged at the opening of the shell. By setting the top cover to comprise a cover body and a connecting side wall and forming a groove between the cover body and the connecting side wall, during assembly, the end of the shell can be inserted into the groove and connected with the top cover. Thus, when the electrode assembly cyclically expands and generates gas during charging and discharging, the force acting on the connecting portion of the shell and the top cover causes the shell to deform outwardly, and the connecting side wall supports and limits the shell, thereby limiting the deformation of the shell to a certain extent, reducing the risk of fatigue cracking of the connecting structure between the shell and the top cover, improving the failure of the connecting structure between the shell and the top cover, and prolonging the service life of the battery monomer. BRIEF DESCRIPTION OF DRAWINGS

[0051] Fig. 1 is a structural schematic diagram of a vehicle according to an embodiment of the present application;

[0052] Fig. 2 is a perspective exploded schematic diagram of a battery according to an embodiment of the present application;

[0053] Fig. 3 is a top view of a battery cell according to an embodiment of the present application;

[0054] Fig. 4 is a sectional view of Fig. 3 in the direction of A-A;

[0055] Fig. 5 is an enlarged view of B in Fig. 4;

[0056] Fig. 6 is a schematic diagram of deformation of a connection between a shell and a top cover when subjected to force according to an embodiment of the present application;

[0057] Fig. 7 is a schematic diagram of cracking of a connection between a shell and a top cover when subjected to force according to the prior art. DETAILED DESCRIPTION

[0058] It should be noted that the embodiments and technical features in the present application can be combined with each other without conflict, and the detailed description in the specific embodiments should be understood as an explanation and illustration of the purpose of the present application, and should not be regarded as an improper limitation of the present application.

[0059] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application; the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion.

[0060] In the description of the embodiments of the present application, the technical terms "first", "second", "third" and the like 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 technical features indicated. In the description of the embodiments of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly and specifically limited.

[0061] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearance of the phrase in various places in the specification does not necessarily all refer to the same embodiment, or necessarily alternatives to other embodiments. It will be explicitly and implicitly appreciated by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0062] In the description of the embodiments of the present application, the term "and / or" is merely an association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which can represent the three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are "or" relationship.

[0063] In the description of the embodiments of the present application, the technical terms "length", "width", "thickness", "height", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "circumferential", "height direction", "first direction", "second direction" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the embodiments of the present application and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed in a particular orientation, be operated or used, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0064] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0065] In the description of the embodiments of the present application, unless otherwise explicitly specified and limited, the technical term "contact" should be understood in a broad sense, which can be direct contact or contact through an intermediate medium layer, which can be contact between two objects in contact without mutual force, or contact between two objects in contact with mutual force.

[0066] With the development of clean energy, more and more equipment uses electric energy as driving energy, and then as power battery which can store more electric energy and can be charged and discharged repeatedly, such as lithium ion battery. Among them, the power battery is not only applied to energy storage power supply systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric bicycles, electric motorcycles, electric vehicles and other electric vehicles, as well as aerospace and other fields.

[0067] With the vigorous promotion of new energy vehicles by the state, new energy vehicles have ushered in a good opportunity for development. The safety and stability of the vehicle have always been the most concerned by people. Therefore, improving the safety of new energy vehicles will be one of the important factors to determine whether new energy vehicles can be quickly popularized. Improving the safety of the battery is an important way to improve the safety of new energy vehicles.

[0068] In this application, the battery monomer can 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. The embodiments of the present application are not limited thereto. The battery monomer can be in the shape of a cylinder, a cuboid, or other shapes, etc. The embodiments of the present application are also not limited thereto.

[0069] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery monomers to provide higher voltage and capacity. For example, the battery mentioned in the present application can include a battery module or a battery pack, etc. The battery generally includes a box for packaging one or more battery monomers. The box can avoid the influence of liquid or other foreign matters on the charging or discharging of the battery monomer.

[0070] The battery monomer includes an electrode assembly and an electrolyte, and the electrode assembly is composed of a positive electrode sheet, a negative electrode sheet, and a separator. The battery monomer 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 current collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the positive electrode active material layer protrudes from the positive electrode current collector with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer serves as a positive electrode tab. Taking a lithium ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the negative electrode active material layer protrudes from the negative electrode current collector with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer serves as a negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that no fuse occurs when passing a large current, the number of positive electrode tabs is multiple and stacked together, and the number of negative electrode tabs is multiple and stacked together. The material of the separator can be PP (polypropylene) or PE (polyethylene), etc.

[0071] Exemplarily, the positive electrode current collector has two opposite surfaces in the thickness direction thereof, and the positive electrode active material is disposed on either one or both of the two opposite surfaces of the positive electrode current collector.

[0072] Exemplarily, the positive electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be employed. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver, and silver alloy, etc.) on a polymer material base material (e.g., a base material of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0073] Exemplarily, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative electrode current collector.

[0074] Exemplarily, the negative electrode current collector can employ a metal foil or a composite current collector. For example, as the metal foil, silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, a carbon electrode, carbon, nickel, or titanium, etc. can be employed.

[0075] Exemplarily, the negative electrode current collector has two surfaces opposite in a thickness direction thereof, and the negative electrode active material is disposed on any one or both of the two surfaces of the negative electrode current collector.

[0076] Exemplarily, the negative electrode active material can employ a negative electrode active material for a battery known in the art. As an example, the negative electrode active material can include at least one of artificial graphite, natural graphite, soft carbon, hard carbon, a silicon-based material, a tin-based material, lithium titanate, etc. The silicon-based material can be selected from at least one of elemental silicon, a silicon oxide compound, a silicon-carbon composite, a silicon-nitrogen composite, and a silicon alloy. The tin-based material can be selected from at least one of elemental tin, a tin oxide compound, and a tin alloy. However, the present application is not limited to these materials, and other conventional materials that can be used as a negative electrode active material for a battery can also be used. The negative electrode active material can be used alone or in combination of two or more.

[0077] The battery cell further includes a packaging film and a case. The packaging film is coated on the outside of the electrode assembly, and the case encapsulates the electrode assembly coated with the packaging film, thereby forming the battery cell. The packaging film can be a mylar film, and the case can be an aluminum case. The mylar film and the case are encapsulated after the electrode assembly is wound into a shape, through a mylar coating process and a case insertion process. The mylar film serves to seal and protect the electrode assembly, and the mylar film can effectively insulate the electrode assembly and the case from each other, thereby preventing internal short circuit of the battery cell. The case serves to protect.

[0078] Exemplarily, the shell comprises a top cover and a shell body, the shell is provided with an opening, and the top cover seals the opening to form a sealed space for accommodating the electrode assembly, the electrolyte and the like. The shell can be provided with one or more openings. The top cover can also be provided with one or more openings.

[0079] Exemplarily, at least one electrode terminal is arranged on the shell, and the electrode terminal is electrically connected with the tab of the electrode assembly. The electrode terminal can be directly connected with the tab or indirectly connected with the tab through an adapter. The electrode terminal can be arranged on the top cover or arranged on the shell body.

[0080] Exemplarily, an explosion-proof valve is arranged on the shell. The explosion-proof valve is used for releasing the internal pressure of the battery monomer.

[0081] Exemplarily, the battery monomer can be a cylindrical battery monomer, a prismatic battery monomer, a soft package battery monomer or a battery monomer of other shapes, the prismatic battery monomer includes a square battery monomer, a blade-shaped battery monomer, a multi-prismatic battery monomer, for example, a hexagonal battery monomer, and the like, and the embodiments of the present application are not particularly limited.

[0082] Exemplarily, the battery monomer further comprises a pressure relief structure, which can be arranged on the top cover or arranged on the shell body to release the internal pressure or temperature of the battery monomer.

[0083] The development of battery technology needs to consider various design factors, such as energy density, discharge capacity, charge-discharge rate and other performance parameters, and in addition, the reliability of the battery also needs to be considered.

[0084] In the related art, as shown in FIG. 7, when the shell is deformed outwardly and the connecting structure between the shell and the top cover is stretched due to the force generated when the electrode assembly generates gas during the cycle expansion and the charging and discharging of the electrode assembly, the connection between the shell and the top cover is fatigued and cracked, and there is a problem of failure of the connecting structure between the shell and the top cover.

[0085] In order to improve the problem of failure of the connecting structure between the shell and the top cover and improve the service life of the battery monomer, the embodiments of the present application provide a battery monomer, which comprises a shell, a top cover and an electrode assembly. The shell has an accommodation space and an opening. The top cover sealing cover is arranged at the opening. The electrode assembly is arranged in the accommodation space. The top cover comprises a cover body, a connecting side wall and a groove formed between the cover body and the connecting side wall, and the end of the shell extends into the groove and is connected with the top cover.

[0086] The battery cell provided by the embodiments of the present application is characterized in that the top cover sealing cover is arranged at the opening of the shell, the top cover is provided with a cover body and a connecting side wall, and a groove is formed between the cover body and the connecting side wall. When assembling, the end of the shell can be inserted into the groove and connected with the top cover. Thus, when the electrode assembly cyclically expands and generates gas during charging and discharging, the shell will deform outwardly, and the connecting side wall will limit and support the shell, thereby limiting the continuous deformation of the shell to a certain extent, reducing the risk of fatigue cracking of the connecting structure between the shell and the top cover, improving the failure of the connecting structure between the shell and the top cover, and prolonging the service life of the battery cell.

[0087] The technical solutions described in the embodiments of the present application are suitable for batteries and electric devices using the batteries.

[0088] The battery mentioned in the embodiments of the present application refers to at least one battery cell provided by the embodiments of the present application. One or more battery cells are provided as a single physical module to provide higher voltage and capacity. For example, the battery mentioned in the present application can include a battery module or a battery pack, etc. The battery generally includes a box for packaging one or more battery cells. The box can prevent liquid or other foreign matter from affecting the charging or discharging of the battery cell.

[0089] The electric device can be a vehicle, a mobile phone, a portable device, a notebook computer, a ship, a spacecraft, an electric toy and an electric tool, etc. The vehicle can be a fuel automobile, a gas automobile or a new energy automobile, and the new energy automobile can be a pure electric automobile, a hybrid electric automobile or a range extended automobile, etc. The spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc. The electric toy includes a fixed or mobile electric toy, for example, a game console, an electric automobile toy, an electric ship toy and an electric airplane toy, etc. The electric tool includes a metal cutting electric tool, a grinding electric tool, an assembling electric tool and a railway electric tool, for example, an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact electric drill, a concrete vibrator and an electric planer, etc. The embodiments of the present application do not specially limit the above electric devices.

[0090] It should be noted that the technical solutions described in the embodiments of the present application are not only limited to the above described batteries and electric devices, but also can be applied to all batteries including a box and electric devices using the batteries. However, for the sake of simplicity, the following embodiments are described by taking an electric vehicle as an example.

[0091] Referring to FIG. 1, FIG. 1 is a structural schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 can be internally provided with a controller 200, a motor 300, and a battery 100, and the controller 200 can be configured to control the battery 100 to supply power to the motor 300. For example, the battery 100 can be arranged at the bottom, the front, or the rear of the vehicle 1000. The battery 100 can be configured to supply power to the vehicle 1000, for example, the battery 100 can be configured as an operating power source of the vehicle 1000, and can be configured to supply power to the circuit system of the vehicle 1000, for example, to meet the power demand of the vehicle 1000 during starting, navigation, and operation. In another embodiment of the present application, the battery 100 can be configured not only as an operating power source of the vehicle 1000, but also as a driving power source of the vehicle 1000, to replace or partially replace fuel or natural gas to provide driving power to the vehicle 1000.

[0092] In order to meet different power demands, the battery 100 can include a plurality of battery cells 10, and the battery cell 10 can be the smallest unit of a battery 100 module or a battery 100 pack. The plurality of battery cells 10 can be connected in series, in parallel, or in a mixed connection, and the mixed connection means that the plurality of battery cells 10 are connected in series and in parallel. The plurality of battery cells 10 can be directly connected in series, in parallel, or in a mixed connection, and the plurality of battery cells 10 can be accommodated in a box. Of course, the battery 100 can be a plurality of battery cells 10 connected in series, in parallel, or in a mixed connection to form a battery 100 module, and a plurality of battery 100 modules can be connected in series, in parallel, or in a mixed connection to form a whole and can be accommodated in a box. The battery 100 can also include other structures, for example, the battery 100 can also include a busbar component for realizing the electrical connection between the plurality of battery cells 10. Each battery cell 10 can be a secondary battery or a primary battery, and can be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 10 can be a cylinder, a flat body, a cuboid, or other shapes.

[0093] Referring to FIG. 2, the battery 100 includes a battery box 20 and at least one battery cell 10 (not shown in the figure), and the battery cell 10 is arranged in the mounting space of the battery box 20.

[0094] The battery box 20 can be a simple cuboid or a cylinder or a sphere, or can be a complex cuboid structure composed of a simple cuboid or a cylinder or a sphere. The material of the battery box 20 can be an alloy material such as an aluminum alloy or an iron alloy, or a high polymer material such as polycarbonate or polyisocyanurate foam plastic, or a composite material such as glass fiber and epoxy resin.

[0095] The battery box 20 is used to accommodate the battery monomer 10, and the battery box 20 can be of various structures. In some embodiments, the battery box 20 can include a first box body part 21 and a second box body part 22, the first box body part 21 and the second box body part 22 are mutually covered, and the first box body part 21 and the second box body part 22 jointly define a mounting space for accommodating the battery monomer 10. The second box body part 22 can be a hollow structure with one end open, and the first box body part 21 is a plate-shaped structure, which is covered on the open side of the second box body part 22 to form the battery box 20 with the mounting space; the first box body part 21 and the second box body part 22 can also be hollow structures with one side open, and the open side of the first box body part 21 is covered on the open side of the second box body part 22 to form the battery box 20 with the mounting space. Of course, the first box body part 21 and the second box body part 22 can be of various shapes, such as a cylinder, a cuboid, etc.

[0096] In order to improve the sealing performance of the first box body part 21 and the second box body part 22 after being connected, a sealing member such as sealing glue, a sealing ring, etc. can be arranged between the first box body part 21 and the second box body part 22.

[0097] Suppose that the first box body part 21 is covered on the top of the second box body part 22, the first box body part 21 can also be called an upper box cover, and the second box body part 22 can also be called a lower box cover.

[0098] In the battery 100, the battery monomer 10 can be one or multiple. If the battery monomer 10 is multiple, the multiple battery monomers 10 can be connected in series, in parallel or in a mixed manner, and the mixed manner means that the multiple battery monomers 10 are connected in series and in parallel. The multiple battery monomers 10 can be directly connected in series, in parallel or in a mixed manner, and then the whole of the multiple battery monomers 10 is accommodated in the battery box 20; of course, the multiple battery monomers 10 can be first connected in series, in parallel or in a mixed manner to form a battery 100 module, and then multiple battery 100 modules are connected in series, in parallel or in a mixed manner to form a whole, which is accommodated in the battery box 20.

[0099] Exemplarily, the battery monomer 10 can include a lithium ion battery monomer 10, a sodium ion battery monomer 10 or a magnesium ion battery monomer 10, etc., and the embodiments of the present application are not limited thereto. The battery monomer 10 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc., and the embodiments of the present application are not limited thereto. The battery monomer 10 is generally divided into three types according to the packaging manner: a cylindrical battery monomer 10, a square battery monomer 10 and a soft package battery monomer 10, and the embodiments of the present application are not limited thereto.

[0100] The battery cell 10 provided by the embodiments of the present application, as shown in FIGS. 3-6, comprises a shell 11, a top cover 12 and an electrode assembly. The shell 11 has a containing space 11a and an opening 11b. The top cover 12 is sealed and covers the opening 11b. The electrode assembly is arranged in the containing space 11a. The top cover 12 comprises a cover body 121, a connecting side wall 122 and a groove 12a formed between the cover body 121 and the connecting side wall 122, and the end of the shell 11 extends into the groove 12a and is connected with the top cover 12.

[0101] Here, the shell 11 can be in the shape of a cylinder, a flat body, a cuboid or other shapes.

[0102] It should be noted that the height direction in the embodiments of the present application is the direction of entering the containing space 11a from the opening 11b, or the opposite direction. When the shell 11 is in the shape of a cylinder, the height direction of the shell 11 is the axial direction of the shell 11.

[0103] Exemplarily, the cover body 121 and the connecting side wall 122 are in an integrated structure. The integrated cover body 121 and the connecting side wall 122 can reduce the number of parts, reduce the assembly time, improve the assembly efficiency and the structural strength.

[0104] Of course, the cover body 121 and the connecting side wall 122 can also be in a split structure, for example, the connecting side wall 122 is welded on the side of the cover body 121 close to the electrode assembly. The split cover body 121 and the connecting side wall 122 are beneficial to molding.

[0105] Here, the top cover 12 is provided with the cover body 121 and the connecting side wall 122, and the groove 12a is formed between the cover body 121 and the connecting side wall 122. On the one hand, when the top cover 12 and the shell 11 are assembled, the end of the shell 11 is first extended into the groove 12a of the top cover 12, and then the shell 11 is connected with the top cover 12, which is beneficial to positioning the shell 11, thereby improving the assembly efficiency. On the other hand, when the electrode assembly is cyclically expanded and gas is generated during charging and discharging, the connection between the shell 11 and the top cover 12 is subjected to force, the shell 11 will deform outwardly, the top cover 12 limits the shell 11 between the cover body 121 and the connecting side wall 122 through the groove 12a, and the connecting side wall 122 limits and supports the shell 11, thereby limiting the shell 11 from further deforming outwardly to a certain extent, 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.

[0106] The battery monomer 10 provided by the embodiment of the present application, the top cover 12 sealing cover is arranged at the opening 11b of the shell 11, by setting the top cover 12 to include the cover body 121 and the connecting side wall 122, and forming the groove 12a between the cover body 121 and the connecting side wall 122, when assembling, the end of the shell 11 can be inserted into the groove 12a and connected with the top cover 12, thereby, when the force is generated to the connecting part of the shell 11 and the top cover 12 when the electrode assembly circulates and expands and the gas is generated during charging and discharging, the shell 11 will deform outwardly, and the connecting side wall 122 will limit and support the shell 11, so that the deformation of the shell 11 can be limited to a certain extent, the risk of fatigue cracking of the connecting structure between the shell 11 and the top cover 12 is reduced, the failure problem of the connecting structure between the shell 11 and the top cover 12 is improved, and the service life of the battery monomer 10 is improved.

[0107] It should be noted that the specific manner of connecting the top cover 12 and the shell 11 is not limited here, for example, welding.

[0108] In some embodiments, referring to FIGS. 3-6, the height of the top cover 12 at the groove 12a satisfies that the end of the shell 11 and the top cover 12 can be welded by means of penetration welding. That is, the end of the shell 11 and the top cover 12 can be welded by laser from the outside of the top cover 12, for example, the side wall welding of the end of the shell 11 and the groove 12a in the height direction.

[0109] It can be understood that if the height dimension of the top cover 12 at the groove 12a is too large, the welding efficiency or effect of the laser will be reduced, and therefore the height of the top cover 12 at the groove 12a needs to satisfy that the penetration welding between the end of the shell 11 and the top cover 12 can be achieved.

[0110] Of course, the shell 11 can also be connected with the connecting side wall 122, and the end of the shell 11 can also be welded with the groove wall of the groove 12a while the shell 11 is connected with the connecting side wall 122.

[0111] It should be noted that the specific structure of the shell 11 is not limited here.

[0112] In some embodiments, referring to FIG. 5, the shell 11 includes a body segment 11c and a connecting segment 11d connected with the body segment 11c. The connecting segment 11d is inserted into the groove 12a and connected with the top cover 12, and the distance between the connecting segment 11d and the central axis of the battery monomer 10 is less than the distance between the body segment 11c and the central axis of the battery monomer 10.

[0113] Here, the distance between the connection section 11d and the center axis of the battery cell 10 is smaller than the distance between the body section 11c and the center axis of the battery cell 10, that is, the connection section 11d forms the opening 11b, and the housing 11 is contracted at the opening 11b.

[0114] In this embodiment, by setting the distance between the connection section 11d and the center axis of the battery cell 10 to be smaller than the distance between the body section 11c and the center axis of the battery cell 10, the body section 11c is expanded outward as much as possible while achieving the connection section 11d extending into the groove 12a and connecting with the top cover 12, thereby improving the size of the accommodation space 11a, and further improving the energy density of the battery cell 10.

[0115] In some embodiments, referring to FIG. 5, the housing 11 includes a transition section 11e, the body section 11c and the connection section 11d are connected through the transition section 11e, the plane where the body section 11c is located is parallel to the plane where the connection section 11d is located, and along the direction from the body section 11c to the connection section 11d, the distance between the transition section 11e and the center axis of the battery cell 10 gradually decreases.

[0116] In this embodiment, by setting the distance between the transition section 11e and the center axis of the battery cell 10 to gradually decrease along the direction from the body section 11c to the connection section 11d, the size of the accommodation space 11a can be improved as much as possible, and further the energy density of the battery cell 10 can be improved.

[0117] In some embodiments, referring to FIG. 5 and FIG. 6, the height of the top cover 12 at the groove 12a is H1, wherein 0.2mm≤H1≤1.5mm. For example, 0.2mm, 0.3mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or 1.5mm, and the like.

[0118] The height of the top cover 12 at the groove 12a is the thickness of the groove wall of the top cover 12 at the groove 12a.

[0119] If the height of the top cover 12 at the groove 12a is too large, the welding efficiency or effect of the laser will be reduced, and if the height of the top cover 12 at the groove 12a is too small, the structural strength of the top cover 12 at the groove 12a will be reduced.

[0120] In this embodiment, by setting the height of the top cover 12 at the groove 12a to be 0.2mm-1.5mm, the height of the top cover 12 at the groove 12a can satisfy the penetration welding between the top cover 12 and the end of the housing 11, and the top cover 12 at the groove 12a can have sufficient structural strength.

[0121] In some embodiments, referring to FIGS. 5 and 6, the height of the top cover 12 at the groove 12a is H1, where 0.3mm≤H1≤1mm. For example, 0.3mm, 0.4mm, 0.7mm, 0.9mm, or 1mm, and the like.

[0122] In this embodiment, by setting the height of the top cover 12 at the groove 12a to be 0.3mm-1mm, the penetration welding between the top cover 12 and the end of the shell 11 can be facilitated, and the top cover 12 at the groove 12a has sufficient structural strength.

[0123] In some embodiments, referring to FIGS. 5 and 6, in the cross section perpendicular to the extension direction of the groove 12a, the width of the groove 12a is L1, where 0.4mm≤L1≤3.5mm. For example, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 1mm, 1.3mm, 1.5mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.4mm, or 3.5mm, and the like.

[0124] Here, the width of the groove 12a refers to the dimension of the groove 12a in the thickness direction of the shell 11.

[0125] It can be understood that the greater the width of the groove 12a, the more conducive to the assembly between the shell 11 and the top cover 12, and the strength of the connecting structure of the top end of the shell 11 and the top cover 12.

[0126] In this embodiment, by setting the width of the groove 12a to be 0.4mm-3.5mm, the end of the shell 11 is facilitated to extend into the groove 12a, and the welding area of the end of the shell 11 and the groove wall of the groove 12a is increased, thereby increasing the strength of the connecting structure between the shell 11 and the top cover 12, reducing the risk of cracking of the connecting structure between the shell 11 and the top cover 12, and improving the service life of the battery monomer 10.

[0127] In some embodiments, referring to FIGS. 5 and 6, in the cross section perpendicular to the extension direction of the groove 12a, the width of the groove 12a is L1, where 0.6mm≤L1≤1mm. For example, 0.6mm, 0.7mm, 0.8mm, 0.9mm, or 1mm, and the like.

[0128] In this embodiment, by setting the width of the groove 12a to be 0.6mm-1mm, the connecting structure of the shell 11 and the top cover 12 has sufficient strength while facilitating the manufacturing of the shell 11 and the top cover 12.

[0129] In some embodiments, referring to FIGS. 5 and 6, the height of the connecting side wall 122 is H2, and the height of the cover body is H, where H-0.5mm≤H2≤13mm. That is, the height of the connecting side wall 122 is greater than or equal to the height of the cover body minus 0.5mm and less than or equal to 13mm.

[0130] The connecting side wall 122 in this height range can enable the connecting side wall 122 to have sufficient contact area with the shell 11, so that when the connecting portion of the shell 11 and the top cover 12 is subjected to force generated by the cyclic expansion of the electrode assembly and the generation of gas during charging and discharging, the connecting side wall 122 can sufficiently limit and support the shell 11, so as to limit the shell 11 from continuing to deform outward to some extent, further reduce the risk of fatigue cracking of the connecting structure between the shell 11 and the top cover 12, improve the failure problem of the connecting structure between the shell 11 and the top cover 12, and improve the service life of the battery monomer 10.

[0131] In some embodiments, referring to FIGS. 5 and 6, the height of the connecting side wall 122 is H2, and the height of the cover body is H, where H≤H2≤11mm. That is, the height of the connecting side wall 122 is greater than or equal to the height of the cover body and less than or equal to 11mm.

[0132] In this embodiment, the connecting side wall 122 in this height range can further enable the connecting side wall 122 to have sufficient contact area with the shell 11, so that when the connecting portion of the shell 11 and the top cover 12 is subjected to force generated by the cyclic expansion of the electrode assembly and the generation of gas during charging and discharging, the connecting side wall 122 can sufficiently limit and support the shell 11, so as to limit the shell 11 from continuing to deform outward to some extent, further reduce the risk of fatigue cracking of the connecting structure between the shell 11 and the top cover 12, improve the failure problem of the connecting structure between the shell 11 and the top cover 12, and improve the service life of the battery monomer 10.

[0133] In some embodiments, referring to FIGS. 5 and 6, the thickness of the connecting side wall 122 is L2, where 0.2mm≤L2≤1.5mm. For example, 0.2mm, 0.4mm, 0.5mm, 0.7mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or 1.5mm, and the like.

[0134] In this embodiment, by setting the thickness of the connecting side wall 122 to 0.2mm-1.5mm, the connecting side wall 122 can have sufficient strength, so as to improve the structural strength of the connecting portion of the top cover 12 and the shell 11, while also minimizing the volume of the top cover 12, so as to improve the energy density of the battery monomer 10.

[0135] In some embodiments, referring to FIGS. 5 and 6, the thickness of the connecting side wall 122 is L2, where 0.3mm≤L2≤1mm. For example, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.8mm, 0.9mm, or 1mm, etc.

[0136] In this embodiment, by setting the thickness of the connecting side wall 122 to 0.3mm-1mm, the connecting side wall 122 can be further made to have sufficient strength, so as to improve the structural strength of the connection between the top cover 12 and the shell 11, while further reducing the volume of the top cover 12, so as to improve the energy density of the battery monomer 10.

[0137] In some embodiments, referring to FIGS. 5 and 6, the thickness of the connecting section 11d is L3, where 0.3mm≤L3≤3mm. For example, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.9mm, 1mm, 1.2mm, 1.5mm, 1.6mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, or 3mm, etc.

[0138] Here, the thickness of the connecting section 11d is the thickness of the connection between the shell 11 and the top cover 12, in other words, the thickness of the area where the shell 11 extends into the groove 12a.

[0139] In this embodiment, by setting the thickness of the connecting section 11d to 0.3mm-3mm, the connecting section 11d can be made to have sufficient strength, so as to improve the structural strength of the connection between the top cover 12 and the shell 11, while further reducing the volume of the top cover 12 and the shell 11 as much as possible, so as to improve the energy density of the battery monomer 10.

[0140] In some embodiments, referring to FIGS. 5 and 6, in the cross section perpendicular to the extending direction of the groove 12a, the width of the groove 12a is L1, and the thickness of the connecting section 11d is L3, where 0≤L1-L3≤0.3mm. For example, 0, 0.1mm, 0.15mm, 0.2mm, 0.25mm, or 0.3mm, etc.

[0141] By setting the difference L1-L3 to be in the range of 0-0.3mm, on the one hand, it is conducive to the shell 11 extending into the groove 12a, and on the other hand, it is conducive to the connecting side wall 122 playing a limiting and supporting role on the shell 11 when the shell 11 deforms outward, that is, it is conducive to reducing the situation or degree of deformation of the shell 11.

[0142] In some embodiments, referring to Figs. 5 and 6, the outer side wall of the shell 11 is formed with a stepped surface 11n facing the top cover 12, and the end of the connecting side wall 122 abuts against the stepped surface 11n.

[0143] Here, on one hand, the stepped surface 11n can play a positioning role for the top cover 12, and together with the end surface of the shell 11, form a double positioning effect for the top cover 12, which is beneficial to improve the deformation of the top cover 12, on the other hand, it is also beneficial to increase the structural strength of the shell 11 at the position where the stepped surface 11n is formed.

[0144] In some embodiments, referring to Figs. 5 and 6, the dimension of the stepped surface 11n in the thickness direction of the shell 11 is L4, where 0.1≤L4≤0.5mm. For example, 0.1mm, 0.2mm, 0.3mm, 0.4mm or 0.5mm, etc.

[0145] Here, the dimension of the stepped surface 11n in the thickness direction of the shell 11 is the distance that the stepped surface 11n extends outward along the outer side wall of the shell 11.

[0146] In this embodiment, by setting the dimension of the stepped surface 11n in the thickness direction of the shell 11 to 0.1mm-0.5mm, the positioning of the top cover 12 is achieved while the volume of the shell 11 and the material for molding are reduced as much as possible, which is beneficial to reduce the cost and improve the energy density of the battery monomer 10.

[0147] It should be noted that the extension direction of the groove 12a is not limited here.

[0148] In some embodiments, referring to Figs. 5 and 6, the groove 12a extends along the edge of the top cover 12.

[0149] Here, the groove 12a extends along the edge of the top cover 12, that is, the profile shape of the center line of the groove 12a in the extension direction is completely or approximately the same as the profile shape of the top cover 12 when projected on a plane parallel to the top cover 12.

[0150] It can be understood that the groove 12a extending along the edge of the top cover 12 can make the distance between any two positions of the groove 12a in the extension direction and the edge of the top cover 12 the same, that is, the distance between any two positions of the groove 12a in the extension direction and the outer side wall of the connecting side wall 122 the same, so that the stress near the groove 12a is more uniform.

[0151] It should be noted that the top cover 12 can be formed with the groove 12a in a partial region between the cover body 121 and the connecting side wall 122, or can be formed with the groove 12a in the whole region between the cover body 121 and the connecting side wall 122, i.e. the top cover 12 is provided with a ring of grooves 12a extending along the edge of the top cover 12. Here, the edge of the top cover 12 refers to the outer side wall of the connecting side wall 122.

[0152] In some embodiments, the battery cell 10 is in a cylindrical shape, and at least a partial region of the top cover 12 is provided with the groove 12a.

[0153] Exemplarily, when the battery cell 10 is in a cylindrical shape, the top cover 12 can be provided with a ring of grooves 12a extending along the edge of the top cover 12, or can be partially surrounded by the groove 12a.

[0154] In some embodiments, the battery cell 10 is in a cuboid shape, and at least one long side of the top cover 12 is provided with the groove 12a.

[0155] Here, one long side of the top cover 12 can be provided with the groove 12a, or both long sides of the top cover 12 can be provided with the groove 12a.

[0156] When the battery cell 10 is in a rectangular shape, the top cover 12 and the shell 11 are more likely to be deformed outward and cracked at the large face, i.e. the connecting structure of the top cover 12 and the shell 11 at the long side of the top cover 12 is failed, thus, by providing the groove 12a at the long side of the top cover 12, the problem of the connecting structure failure between the top cover 12 and the shell 11 can be effectively improved.

[0157] A partial or whole region of the long side can be formed with the groove 12a, or a partial or whole region of the short side can be formed with the groove 12a. In some embodiments, the top cover 12 is provided with a ring of grooves 12a corresponding to the contour of the top cover 12.

[0158] In some embodiments, the material of the top cover 12 and / or the shell 11 is aluminum.

[0159] It can be understood that when the material of the top cover 12 and / or the shell 11 is aluminum, by forming the groove 12a between the cover body 121 and the connecting side wall 122, when assembling, the end of the shell 11 can be inserted into the groove 12a and connected with the top cover 12, so that when the electrode assembly circulates and expands and the force generated by the charging and discharging gas acts on the connection between the shell 11 and the top cover 12, the shell 11 will deform outwardly, and the connecting side wall 122 will limit and support the shell 11, thereby limiting the continuous deformation of the shell 11 to a certain extent, reducing the risk of fatigue cracking of the connection structure between the shell 11 and the top cover 12, improving the failure of the connection structure between the shell 11 and the top cover 12, and improving the service life of the battery monomer 10.

[0160] In some embodiments, referring to FIGS. 5 and 6, the height of the cover body 121 is H, wherein 1 mm≤H≤5 mm. For example, 1 mm, 1.2 mm, 1.4 mm, 1.5 mm, 1.8 mm, 2 mm, 3 mm, 3.4 mm, 3.5 mm, 3.7 mm, 4 mm, 4.4 mm, 4.5 mm, 4.7 mm, or 5 mm, and the like.

[0161] In this embodiment, by setting the height of the cover body 121 to 1 mm-5 mm, the top cover 1212 has sufficient strength for protecting the electrode assembly in the accommodation space 11a, while reducing the weight and volume of the battery monomer 10, and reducing the material of the top cover 12, reducing the cost, and improving the comprehensive performance of the battery 100.

[0162] In other embodiments, referring to FIGS. 5 and 6, the height of the cover body 121 is H, wherein 1.5 mm≤H≤3 mm. For example, 1.5 mm, 1.7 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, and the like.

[0163] In this embodiment, by setting the height of the cover body 121 to 1.5 mm-3 mm, the top cover 12 has sufficient strength for protecting the electrode assembly in the accommodation space 11a, while further reducing the weight and volume of the battery monomer 10, reducing the material of the top cover 12, reducing the cost, and further improving the comprehensive performance of the battery 100.

[0164] It should be noted that the height H of the cover body, the height H1 of the top cover 12 at the groove 12a, the height H2 of the connecting side wall 122, the width L1 of the groove 12a, the thickness L2 of the connecting side wall 122, the thickness L3 of the connecting section 11d, the size L4 of the step surface 11n in the thickness direction of the shell 11 and the like can be obtained by high-precision thickness gauges, vernier calipers and the like and calculation when the top cover 12 is not assembled at room temperature.

[0165] The battery cell 10 of the present application will be further described below in combination with specific test examples.

[0166] The test sample of the embodiment of the present application: the top cover 12 includes a cover body 121 and a connecting piece, the cover body 121 has a channel passing through the cover body 121, and the connecting piece is arranged on the side of the cover body 121 close to the electrode assembly and closes the channel.

[0167] Through the charge-discharge cycle experiments of the test sample and the control group of the embodiment of the present application, and recording the number of cycles, the cycle numbers of the five control groups of the embodiment of the present application are 3010, 3312, 3126, 3385 and 3215, the average cycle number of the five test samples of the embodiment of the present application is 3209 times, the cycle numbers of the five test samples of the control group are 3916, 3852, 3733, 3949 and 3871, the average cycle number of the five test samples of the embodiment of the present application is 3864 times, the average of the test sample of the embodiment of the present application is improved by 20.4% compared with the average of the control group, when the electrode assembly is cycled and expanded and gas is generated by charge and discharge, force will be generated on the connection between the shell 11 and the top cover 12, the cycle number of the battery cell 10 provided by the embodiment of the present application is much larger than that of the control group, that is, the battery cell 10 provided by the embodiment of the present application reduces the risk of cracking of the connection structure between the shell 11 and the top cover 12, improves the problem of failure of the connection structure between the shell 11 and the top cover 12, and improves the service life of the battery cell 10.

[0168] In the description of the present application, the description of the terms "in an embodiment", "in some embodiments", "in another embodiment", "in yet another embodiment", or "exemplary" and the like means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are contained in at least one embodiment or example of the embodiments of the present application. In the present application, the exemplary description of the above terms is not necessarily for the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, the skilled in the art can combine the different embodiments or examples described in the present application and the features of the different embodiments or examples without contradiction.

[0169] The above descriptions are only the preferred embodiment of the present application, not intended to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall fall into the scope of protection of the present application.

Claims

1. A battery cell, comprising: a housing having a receiving space and an opening; A top cover and a sealing cover are provided at the opening; an electrode assembly, disposed in the accommodation space; The top cover includes a cover body, a connecting side wall, and a groove formed between the cover body and the connecting side wall. The end of the shell extends into the groove and is connected to the top cover.

2. The battery cell according to claim 1, wherein the outer shell includes a main body segment and a connecting segment connected to the main body segment, the connecting segment extends into the groove and is connected to the top cover, and the distance between the connecting segment and the central axis of the battery cell is smaller than the distance between the main body segment and the central axis of the battery cell.

3. The battery cell according to any one of claims 1-2, wherein the outer shell includes a transition section, the main body section and the connecting section are connected through the transition section, the plane where the main body section is located is parallel to the plane where the connecting section is located, and along the direction from the main body section to the connecting section, the distance between the transition section and the central axis of the battery cell gradually decreases.

4. The battery cell according to any one of claims 1 to 3, wherein the height of the top cover at the groove is H1, 0.2mm≤H1≤1.5mm; and / or, In a cross section perpendicular to an extending direction of the groove, a width of the groove is L1, wherein 0.4 mm ≤ L1 ≤ 3.5 mm.

5. The battery cell according to any one of claims 1 to 3, wherein the height of the top cover at the groove is H1, wherein: 0.3mm≤H1≤1mm; and / or, In a cross section perpendicular to an extending direction of the groove, a width of the groove is L1, wherein 0.6 mm ≤ L1 ≤ 1 mm.

6. The battery cell according to any one of claims 1 to 5, wherein the height of the connecting side wall is H2, the height of the cover body is H, and H-0.5mm≤H2≤13mm; and / or, The thickness of the connecting side wall is L2, wherein 0.2 mm ≤ L2 ≤ 1.5 mm.

7. The battery cell according to claim 3, wherein the thickness of the connecting section is L3, 0.3mm≤L3≤3mm; or, In a cross section perpendicular to the extending direction of the groove, the width of the groove is L1, and the thickness of the connecting section is L3, wherein 0≤L1-L3≤0.3 mm. 8 . The battery cell according to claim 1 , wherein an outer side wall of the housing is formed with a stepped surface facing the top cover, and an end portion of the connecting side wall abuts against the stepped surface.

9. The battery cell according to claim 8, wherein the dimension of the step surface in the thickness direction of the housing is L4, wherein: 0.1mm≤L4≤0.5mm. 10 . The battery cell according to claim 1 , wherein the groove extends along an edge of the top cover.

11. The battery cell according to any one of claims 4 to 10, wherein the top cover and / or the outer shell are made of aluminum.

12. The battery cell according to any one of claims 1 to 11, wherein the battery cell is in a rectangular parallelepiped shape, and at least one long side of the top cover is provided with the groove; or The battery cell is cylindrical in shape, and the groove is provided in at least a portion of the top cover.

13. The battery cell according to any one of claims 1 to 12, wherein the height of the cover body is H, 1mm≤H≤5mm.

14. A battery comprising at least one battery cell according to any one of claims 1 to 13.

15. An electrical device comprising the battery according to claim 14, wherein the battery is used to provide electrical energy for the electrical device.

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