Battery monomer, battery and electric device

Abstract

The embodiment of the utility model provides a battery monomer, a battery and a power utilization device. The battery monomer comprises a shell, a top cover and an electrode assembly, the housing has an accommodation space and an opening. And the top cover hermetically covers the opening. The electrode assembly is arranged in the accommodating space. Wherein the inner side wall of at least part of the area, located at the opening, of the shell is thickened to form a thickened area, a connecting area matched with the thickened area is formed on the edge of the top cover, and the connecting area is connected with the thickened area. According to the battery monomer provided by the embodiment of the invention, the inner side wall of the at least partial region, located at the opening, of the shell is thickened to form the thickened region, so that the structural strength of the joint of the shell and the top cover is improved, the connection strength of the shell and the top cover is improved, and the risk of fatigue cracking of the connection structure between the shell and the top cover is reduced; the problem of failure of a connecting structure between the shell and the top cover is solved, the expansion resistance of the shell is improved, and the service life of the battery monomer is prolonged.

Description

Technical Field

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

[0002] This section is intended to provide a background or context to 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 battery production process, after the bare cell is placed in the shell and the top cover is closed, the shelled cell 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 failure of the connection structure between the shell and the top cover. 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 inner wall of at least a part of the area of ​​the shell located at the opening is thickened to form a thickened area, and the edge of the top cover is formed with a connecting area adapted to the thickened area, and the connecting area is connected to the thickened area.

[0010] The battery cell provided in the embodiment of the present application is formed by thickening the inner wall of at least a part of the area of ​​the outer shell located at the opening to form a thickened area, and a connection area adapted to the thickened area is formed at the edge of the top cover, and the connection area is connected to the thickened area, thereby improving the structural strength of the connection between the outer shell and the top cover, thereby improving the connection strength 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 increasing the service life of the battery cell.

[0011] In some embodiments, the thickened area extends along an edge of the opening.

[0012] In this embodiment, the thickened area extends along the edge of the opening, so that the force on the shell can be more uniform.

[0013] In some embodiments, the wall thickness of the thickened region is the same along the extension direction of the thickened region; or, the wall thickness of the thickened region increases along the extension direction of the thickened region; or, the wall thickness of the thickened region first increases and then decreases along the extension direction of the thickened region.

[0014] In this way, the wall thickness of the thickened area can be designed according to the needs, that is, according to the different forces in different areas of the shell, so as to improve the structural strength of the shell in a targeted manner, while ensuring that the connection between the top cover and the shell has sufficient connection strength, reducing the weight and volume of the battery cell, reducing the material used in the shell, reducing costs, and improving the overall performance of the battery.

[0015] In some embodiments, the thickened region includes a plurality of sub-regions arranged in sequence along the extension direction of the thickened region, each sub-region has the same wall thickness, and any two adjacent sub-regions have different wall thicknesses.

[0016] In this embodiment, the thickened area is configured to include multiple sub-areas, and the multiple sub-areas increase in a step-like manner, or the multiple sub-areas first increase in a step-like manner and then decrease. In this way, the wall thickness of the thickened area can be designed in a targeted manner according to the needs, that is, according to the different forces in different areas of the shell, so as to improve the structural strength of the shell in a targeted manner, while ensuring that the connection between the top cover and the shell has sufficient connection strength, reducing the weight and volume of the battery cell, reducing the material used in the shell, reducing the cost, and improving the overall performance of the battery.

[0017] In some embodiments, the battery cell is in a rectangular parallelepiped shape, and at least one large surface of the housing is provided with the thickened area.

[0018] In some embodiments, the battery cell is cylindrical in shape, and the thickened area is disposed in at least a portion of the housing.

[0019] In some embodiments, the length dimension of the large surface of the shell is L, and the length dimension of the thickened area is L1, wherein:

[0020] In this embodiment, by setting the ratio of the length of the thickened area on the large surface to the length of the large surface of the shell to 0.2-0.8, the shell has sufficient strength while reducing the weight and volume of the shell, reducing the material used for the shell, reducing costs, and improving the energy density of the battery.

[0021] In some embodiments, the wall thickness of the shell in other regions except the thickened region is T, the wall thickness of the thickened region is the same along the extension direction of the thickened region, and the wall thickness of the thickened region is T1, wherein,

[0022] In this embodiment, the ratio of the difference between the wall thickness of the thickened area and the wall thickness of other areas of the shell except the thickened area is set to 0.2-2, so that the shell has sufficient strength while reducing the weight and volume of the shell, reducing the material used in the shell, reducing costs, and improving the energy density of the battery.

[0023] In some embodiments, the wall thickness of the thickened area is T1, wherein 0.5 mm ≤ T1 ≤ 1.5 mm.

[0024] In this embodiment, by setting the wall thickness of the thickened area to 0.5 mm-1.5 mm, the shell has sufficient strength while reducing the weight and volume of the shell, reducing the material used for the shell, reducing costs, and improving the energy density of the battery.

[0025] In some embodiments, the thickened area includes a first sub-area, two second sub-areas and two third sub-areas, the two second sub-areas are respectively connected to the two sides of the first sub-area, the two third sub-areas are respectively connected to the two second sub-areas, and the wall thickness of the first sub-area, the second sub-area and the third sub-area decreases successively.

[0026] In this embodiment, by designing the wall thickness of the thickened area to first increase in a step-like manner and then decrease in a step-like manner, it is beneficial to design the wall thickness of the thickened area in a targeted manner, thereby specifically improving the structural strength of the outer shell, while ensuring that the connection between the top cover and the outer shell has sufficient connection strength, reducing the weight and volume of the battery cell, reducing the material used in the outer shell, reducing costs, and improving the overall performance of the battery.

[0027] In some embodiments, the battery cell is in a rectangular shape, at least one large surface of the shell is provided with the thickened area, the length dimension of the large surface of the shell is L, and the length dimension of the first sub-area is L2, wherein,

[0028] In this embodiment, by setting the ratio of the length of the first sub-region to the length of the large surface of the shell to 0.2-0.6, and the wall thickness of the first sub-region is greater than the wall thickness of the second sub-region and the third sub-region, that is, the ratio of the length of the maximum wall thickness in the thickened area to the length of the large surface of the shell is set to 0.2-0.6, so that the shell has sufficient strength while reducing the weight and volume of the shell, reducing the material used in the shell, reducing costs, and improving the energy density of the battery.

[0029] In some embodiments, the length dimension of the second sub-region is L3, wherein L3<L2, and 1mm≤L3≤0.5(L-L2-3mm).

[0030] In this embodiment, by setting the length of the second sub-area to 1mm≤L3≤0.5 (L-L2-3mm), the shell has sufficient strength while reducing the weight and volume of the shell, reducing the material used for the shell, reducing costs, and improving the energy density of the battery.

[0031] In some embodiments, the battery cell is in a rectangular shape, at least one large surface of the shell is provided with the thickened area, the wall thickness of other areas of the shell except the thickened area is T, and the wall thickness of the first sub-area is T2, wherein, Alternatively, 0.5mm≤T2≤1.5mm.

[0032] In some embodiments, the wall thickness of the second sub-region is T3, wherein T<T3<2T.

[0033] In this embodiment, the wall thickness of the second sub-region is set to T<T3<2T and is smaller than the wall thickness of the first sub-region, so as to specifically strengthen the structural strength of the shell.

[0034] In some embodiments, the wall thickness of the third sub-region is T4, wherein T<T4<1.5T.

[0035] In this embodiment, the wall thickness of the third sub-region is set to T<T4<1.5T, which is smaller than the wall thickness of the second sub-region, so as to specifically strengthen the structural strength of the housing.

[0036] In some embodiments, the shell further includes transition regions disposed at both ends of the thickened region, and the wall thickness of the transition regions gradually increases or decreases along the extension direction of the thickened region;

[0037] The length dimension of the large surface of the shell is L, the wall thickness of the thickened area is the same along the extension direction of the thickened area, and the length dimension of the thickened area is L1, and the length dimension of the inner wall of the transition area is L4, wherein L4<L-L1.

[0038] In this embodiment, transition areas are provided at both ends of the thickened area so that the thickened area is smoothly connected to other areas of the shell, thereby improving the structural strength of the shell and also having an anti-scratch effect. In addition, by setting the length dimension of the inner side wall of the transition area to L4<L-L1, the setting of the slope and length of the transition area is achieved.

[0039] In some embodiments, an angle A is included between the inner side wall of the transition region and the inner side wall of the thickened region, wherein 90<A<180.

[0040] In this embodiment, the angle between the inner side wall of the transition area and the inner side wall of the thickened area is set to 90°<A<180°, thereby achieving the setting of the slope and length of the transition area.

[0041] In some embodiments, the top cover and / or the housing are made of aluminum.

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

[0043] The battery provided in the embodiment of the present application includes at least one battery cell of the embodiment of the present application, and a thickened area is formed by thickening the inner wall of at least a part of the area of ​​the outer shell located at the opening, and a connection area adapted to the thickened area is formed at the edge of the top cover, and the connection area is connected to the thickened area. Thus, the structural strength of the connection between the outer shell and the top cover is improved, thereby improving the connection strength 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.

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

[0045] The electrical device provided in the embodiment of the present application includes a battery, and the battery includes at least one battery cell of the embodiment of the present application. A thickened area is formed by thickening the inner wall of at least a part of the area of ​​the outer shell located at the opening, and a connection area adapted to the thickened area is formed at the edge of the top cover, and the connection area is connected to the thickened area. Thus, the structural strength of the connection between the outer shell and the top cover is improved, thereby improving the connection strength 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 increasing the service life of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

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

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

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

[0049] Figure 4 for Figure 3 Section view in AA direction;

[0050] Figure 5 for Figure 4 The enlarged view of point B in the middle;

[0051] Figure 6 A schematic diagram of the structure of a housing provided in the first embodiment of the present application;

[0052] Figure 7 for Figure 6 A top view of the housing is shown;

[0053] Figure 8 for Figure 7 Enlarged view of point C in the middle;

[0054] Fig. 9 A schematic structural diagram of a housing provided in the second embodiment of the present application.

[0055] Description of Reference Numerals

[0056] 10. Battery cell; 11. Shell; 11a. Accommodation space; 11b. Opening; 11c. Thickened area; 11d. First sub-area; 11e. Second sub-area; 11f. Third sub-area; 11n. Transition area; 12. Top cover; 20. Battery box; 21. First box body; 22. Second box body; 100. Battery; 200. Controller; 300. Motor; 1000. Vehicle. DETAILED DESCRIPTION

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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).

[0070] Illustratively, the positive electrode current collector has two surfaces opposite to each other in its thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0071] Exemplarily, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may 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 substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0072] Illustratively, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0073] For example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used.

[0074] Illustratively, the negative electrode current collector has two surfaces opposite to each other in its thickness direction, and the negative electrode active material is disposed on any one or both of the two opposite surfaces of the negative electrode current collector.

[0075] Exemplarily, the negative electrode active material may adopt the negative electrode active material for the battery known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0076] 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.

[0077] Exemplarily, the housing includes a top cover and an outer shell, the housing is provided with an opening, and the top cover closes the opening to form a closed space for accommodating substances such as the electrode assembly and the electrolyte. The housing may be provided with one or more openings. The top cover may also be provided with one or more openings.

[0078] Exemplarily, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the electrode tab of the electrode assembly. The electrode terminal can be directly connected to the electrode tab, or indirectly connected to the electrode tab through an adapter. The electrode terminal can be provided on the top cover, or on the housing.

[0079] Exemplarily, an explosion-proof valve is provided on the housing, and the explosion-proof valve is used to release the internal pressure of the battery cell.

[0080] Exemplarily, the battery cells may be cylindrical battery cells, prismatic battery cells, soft-pack battery cells or battery cells of other shapes. Prismatic battery cells include square-shell battery cells, blade-shaped battery cells, and polygonal prismatic batteries. Polygonal prismatic batteries are, for example, hexagonal prismatic batteries, etc. There are no particular limitations on the embodiments of the present application.

[0081] Exemplarily, the battery cell further includes a pressure relief structure, which may be disposed on the top cover or the outer shell to release the internal pressure or temperature of the battery cell.

[0082] The development of battery technology must take into account many design factors at the same time, such as energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0083] In the related art, 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, resulting in the problem of failure of the connection structure between the outer shell and the top cover.

[0084] In order to improve the problem of failure of the connection structure between the outer shell and the top cover and to increase the service life of the battery cell, an embodiment of the present application provides a battery cell, which includes an outer shell, a top cover and an electrode assembly. The outer shell has a accommodating space and an opening. The top cover sealing cover is arranged at the opening. The electrode assembly is arranged in the accommodating space. Among them, the inner side wall of at least a part of the area of ​​the outer shell located at the opening is thickened to form a thickened area, and the edge of the top cover is formed with a connection area adapted to the thickened area, and the connection area is connected to the thickened area. The pressure resistance and long-term reliability of the weld are improved, and the assembly and weldability of the top cover and the outer shell are improved.

[0085] The battery cell provided in the embodiment of the present application is formed by thickening the inner wall of at least a part of the area of ​​the outer shell located at the opening to form a thickened area, and a connection area adapted to the thickened area is formed at the edge of the top cover, and the connection area is connected to the thickened area, thereby improving the structural strength of the connection between the outer shell and the top cover, thereby improving the connection strength 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 increasing the service life of the battery cell.

[0086] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0087] 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.

[0088] 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.

[0089] 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.

[0090] 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.

[0091] In order to meet different power requirements, the battery 100 may include a plurality of battery cells 10, which refers to the smallest unit that constitutes a battery module or a battery pack 100. A plurality of battery cells 10 may be connected in series, in parallel, or in a mixed connection, and a mixed connection refers to a plurality of battery cells 10 that are both connected in series and in parallel. A plurality of battery cells 10 may be directly connected in series, in parallel, or in a mixed connection, and then the whole formed by the plurality of battery cells 10 is accommodated in a box; of course, the battery 100 may also be a plurality of battery cells 10 that are first connected in series, in parallel, or in a mixed connection to form a battery module, and then the plurality of battery modules are connected in series, in parallel, or in a mixed connection to form a whole, and are accommodated in a 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 the plurality of battery cells 10. Each battery cell 10 may be a secondary battery or a primary battery; it may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 10 may be cylindrical, flat, rectangular, or in other shapes.

[0092] Please refer to Figure 2 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 .

[0093] 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.

[0094] The battery box 20 is used to accommodate the battery cell 10, and the battery box 20 can be a variety of structures. In some embodiments, the battery box 20 may include a first box body 21 and a second box body 22, the first box body 21 and the second box body 22 cover each other, and the first box body 21 and the second box body 22 jointly define an installation space for accommodating the battery cell 10. The second box body 22 may be a hollow structure with one end open, the first box body 21 is a plate-like structure, and the first box body 21 covers the open side of the second box body 22 to form a battery box 20 with an installation space; the first box body 21 and the second box body 22 may also be a hollow structure with one side open, and the open side of the first box body 21 covers the open side of the second box body 22 to form a battery box 20 with an installation space. Of course, the first box body 21 and the second box body 22 may be in a variety of shapes, such as a cylinder, a cuboid, etc.

[0095] 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 .

[0096] 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.

[0097] 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 can be 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, and then the battery modules can be connected in series, in parallel, or in a mixed connection to form a whole, and then accommodated in the battery box 20.

[0098] For example, the battery cell 10 may include a lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, 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, square battery cells, and soft-pack battery cells, which is not limited in the embodiments of the present application.

[0099] The present application embodiment provides a battery cell. Figures 3 to 9 The battery cell 10 includes a housing 11, a top cover 12 and an electrode assembly. The housing 11 has a receiving space 11a and an opening 11b. The top cover 12 is provided with a sealing cover at the opening 11b. The electrode assembly is provided in the receiving space 11a. The inner side wall of at least a part of the area of ​​the housing 11 at the opening 11b is thickened to form a thickened area 11c, and the edge of the top cover 12 is formed with a connection area adapted to the thickened area 11c, and the connection area is connected to the thickened area 11c.

[0100] Here, the housing may be in a cylindrical, flat, rectangular or other shapes.

[0101] 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.

[0102] It should be noted that the specific method of connecting the top cover 12 and the outer shell 11 is not limited here, for example, welding, that is, the top cover 12 and the outer shell 11 are welded in the area located at the opening 11b.

[0103] The edge of the top cover 12 is formed with a connection area adapted to the thickened area 11 c , which is conducive to achieving connection reliability between the connection area and the thickened area 11 c .

[0104] The top cover 12 is generally perpendicular to the side of the shell 11. The shell 11 deforms outward, and a shear force parallel to the top cover 12 is generated at the connection between the shell 11 and the top cover 12. By providing a thickened area 11c on the inner side wall of at least a portion of the area of ​​the shell 11 at the opening 11b, the structural strength of the shell 11 at the opening 11b is improved.

[0105] The battery cell 10 provided in the embodiment of the present application is achieved by thickening the inner wall of at least a portion of the area of ​​the outer shell 11 located at the opening 11b to form a thickened area 11c, and the edge of the top cover 12 is formed with a connection area adapted to the thickened area 11c, and the connection area is connected to the thickened area 11c, thereby improving the structural strength of the connection between the outer shell 11 and the top cover 12, thereby improving the connection strength 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 shell's expansion resistance, and increasing the service life of the battery cell 10.

[0106] For some examples, see Figure 6 and Fig. 9 , the thickened area 11c extends along the edge of the opening 11b.

[0107] Here, the thickened area 11c extends along the edge of the opening 11b, that is, the thickened area 11c extends along the edge of the top cover 12, that is, when projected on a plane parallel to the top cover 12, the contour shape of the center line of the thickened area 11c along the extension direction is exactly the same or approximately the same as the edge shape of the opening 11b.

[0108] The inner wall of at least a portion of the outer shell 11 at the opening 11b is thickened to form a thickened area 11c. The thickened area 11c may be formed by a portion of the outer shell 11 at the opening 11b, or by the entire area of ​​the outer shell 11 at the opening 11b, that is, the outer shell 11 is provided with a thickened area 11c surrounding the opening 11b.

[0109] In this embodiment, the thickened area 11 c extends along the edge of the opening 11 b , so that the force applied to the housing 11 is more uniform.

[0110] Exemplarily, when the battery cell 10 is cylindrical, at least a portion of the outer shell 11 is provided with a thickened area 11 c.

[0111] The top cover 12 may be provided with a circle of thickened area 11 c extending along the edge of the top cover 12 , or may be partially surrounded by the thickened area 11 c .

[0112] Exemplarily, when the battery cell 10 is in a rectangular parallelepiped shape, at least one large surface of the housing 11 is provided with a thickened area 11 c .

[0113] Here, the thickened area 11c may be formed in a partial area or the entire area of ​​the large surface at the opening 11b, and of course, the thickened area 11c may also be formed in a partial area or the entire area of ​​the small surface at the opening 11b. In some embodiments, the thickened area 11c is formed in partial areas of the two large surfaces of the housing 11 at the opening 11b, and the thickened area 11c is not formed on the two small surfaces.

[0114] In this embodiment, by providing a thickened area 11c on at least one large surface of the outer shell 11, the structural strength of the outer shell 11 is improved, thereby improving the connection strength between the outer shell 11 and the top cover 12, and reducing the risk of fatigue cracking of the connection structure between the outer shell 11 and the top cover 12.

[0115] It should be noted that the specific structure of the thickened area 11c is not limited here.

[0116] For some examples, see Figure 6 , the wall thickness of the thickened region 11c is the same along the extending direction of the thickened region 11c.

[0117] Here, the distances between any two positions of the thickened area 11 c in its extending direction and the outer wall of the housing 11 can be made the same, so that the force near the thickened area 11 c can be made more uniform.

[0118] In some other embodiments, the wall thickness of the thickened region 11 c increases along the extending direction of the thickened region 11 c.

[0119] The wall thickness of the thickened region 11c increases along the extending direction of the thickened region 11c means that the wall thickness of the thickened region 11c may increase gradually or in a step-like manner along the extending direction of the thickened region 11c.

[0120] In this way, the wall thickness of the thickened area 11c can be designed according to needs, that is, according to the different forces in different areas of the outer shell 11, so as to improve the structural strength of the outer shell 11 in a targeted manner, while ensuring that the connection between the top cover 12 and the outer shell 11 has sufficient connection strength, reducing the weight and volume of the battery cell 10, reducing the material used in the outer shell 11, reducing costs, and improving the overall performance of the battery 100.

[0121] In some other embodiments, please refer to Fig. 9 , the wall thickness of the thickened area 11c first increases and then decreases along the extending direction of the thickened area 11c.

[0122] The wall thickness of the thickened area 11c first increases and then decreases along the extension direction of the thickened area 11c, which means that the wall thickness of the thickened area 11c may first gradually increase and then gradually decrease along the extension direction of the thickened area 11c, or may first increase and then decrease in a step-like manner.

[0123] In this way, the wall thickness of the thickened area 11c can be designed according to needs, that is, according to the different forces in different areas of the outer shell 11, so as to improve the structural strength of the outer shell 11 in a targeted manner, while ensuring that the connection between the top cover 12 and the outer shell 11 has sufficient connection strength, reducing the weight and volume of the battery cell 10, reducing the material used in the outer shell 11, reducing costs, and improving the overall performance of the battery 100.

[0124] For some examples, see Fig. 9 The thickened area 11c includes multiple sub-areas arranged in sequence along the extension direction of the thickened area 11c, each sub-area has the same wall thickness, and any two adjacent sub-areas have different wall thicknesses. That is, the multiple sub-areas increase in a step-like manner, or the multiple sub-areas increase in a step-like manner first and then decrease.

[0125] The wall thickness of each sub-region is the same, that is, a single sub-region is a region of equal wall thickness.

[0126] In this embodiment, the thickened area 11c is configured to include multiple sub-areas, and the multiple sub-areas increase in a step-like manner, or the multiple sub-areas first increase in a step-like manner and then decrease. In this way, the wall thickness of the thickened area 11c can be designed according to needs, that is, according to the different forces in different areas of the outer shell 11, so as to improve the structural strength of the outer shell 11 in a targeted manner, and at the same time, the connection between the top cover 12 and the outer shell 11 has sufficient connection strength, reduce the weight and volume of the battery cell 10, reduce the material used in the outer shell 11, reduce costs, and improve the overall performance of the battery 100.

[0127] For some examples, see Figure 6The length dimension of the large surface of the shell 11 is L, and the length dimension of the thickened area 11c is L1, wherein, For example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7 or 0.8, etc.

[0128] here, It refers to the ratio of the length of the thickened area 11 c on the large surface to the length of the large surface of the shell 11 . The larger the value is, the larger the proportion of the thickened area 11c is. The smaller it is, the smaller the proportion of the thickened area 11c is.

[0129] In this embodiment, by setting the ratio of the length of the thickened area 11c on the large surface to the length of the large surface of the shell 11 to 0.2-0.8, the shell 11 has sufficient strength while reducing the weight and volume of the shell 11, reducing the material used in the shell 11, reducing costs, and improving the energy density of the battery 100.

[0130] For some examples, see Figure 6 , the wall thickness of the shell 11 other than the thickened area 11c is T, the wall thickness of the thickened area 11c is the same along the extension direction of the thickened area 11c, and the wall thickness of the thickened area 11c is T1, wherein, For example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9 or 2, etc.

[0131] The wall thickness of the thickened region 11 c is the same along the extension direction of the thickened region 11 c , that is, the thickened region 11 c in this embodiment is a region of uniform wall thickness.

[0132] here, It refers to the ratio between the difference between the wall thickness of the thickened area 11 c and the wall thickness of other areas of the shell 11 except the thickened area 11 c and the wall thickness of other areas of the shell 11 except the thickened area 11 c. The larger the value is, the greater the wall thickness of the thickened area 11c is relative to other areas of the shell 11 except the thickened area 11c. The smaller it is, the smaller the wall thickness of the thickened area 11 c is relative to other areas of the housing 11 except the thickened area 11 c.

[0133] In this embodiment, the ratio of the difference between the wall thickness of the thickened area 11c and the wall thickness of other areas of the shell 11 except the thickened area 11c is set to 0.2-2, so that the shell 11 has sufficient strength while reducing the weight and volume of the shell 11, reducing the material used in the shell 11, reducing the cost, and improving the energy density of the battery 100.

[0134] For some examples, see Figure 6 The wall thickness of the thickened area 11c is T1, wherein 0.5 mm ≤ T1 ≤ 1.5 mm, for example, 0.5 mm, 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 or 1.5 mm, etc.

[0135] In this embodiment, by setting the wall thickness of the thickened area 11c to 0.5mm-1.5mm, the outer shell 11 has sufficient strength while reducing the weight and volume of the outer shell 11, reducing the material used for the outer shell 11, reducing costs, and improving the energy density of the battery 100.

[0136] For some examples, see Fig. 9 The thickened area 11c includes a first sub-area 11d, two second sub-areas 11e and two third sub-areas 11f. The two second sub-areas 11e are respectively connected to the two sides of the first sub-area 11d, and the two third sub-areas 11f are respectively connected to the two second sub-areas 11e, and the wall thicknesses of the first sub-area 11d, the second sub-area 11e and the third sub-area 11f decrease successively.

[0137] That is, the thickened region 11c includes a first sub-region 11d, a second sub-region 11e, a third sub-region 11f, a second sub-region 11e, and a first sub-region 11d which are sequentially arranged along the extending direction of the thickened region 11c.

[0138] The wall thicknesses of the first sub-region 11d, the second sub-region 11e and the third sub-region 11f decrease in sequence, that is, the wall thickness of the thickened region 11c is stepped, that is, the wall thickness of the thickened region 11c increases first and then decreases.

[0139] Here, the battery cell 10 may be in a cylindrical shape or in a rectangular parallelepiped shape.

[0140] Taking the battery cell 10 as an example, which is in the shape of a rectangular parallelepiped, the thickened area 11c may be disposed in the middle of the large surface of the housing 11.

[0141] In this embodiment, by designing the wall thickness of the thickened area 11c to first increase in a step-like manner and then decrease in a step-like manner, it is beneficial to design the wall thickness of the thickened area 11c in a targeted manner, thereby specifically improving the structural strength of the outer shell 11, while ensuring that the connection between the top cover 12 and the outer shell 11 has sufficient connection strength, reducing the weight and volume of the battery cell 10, reducing the material used in the outer shell 11, reducing costs, and improving the overall performance of the battery 100.

[0142] For some examples, see Fig. 9 The battery cell 10 is in a rectangular shape, at least one large surface of the shell 11 is provided with a thickened area 11c, the length dimension of the large surface of the shell 11 is L, and the length dimension of the first sub-area 11d is L2, wherein, For example, 0.2, 0.3, 0.4, 0.5 or 0.6 and so on.

[0143] here, It refers to the ratio of the length of the first sub-region 11 d to the length of the large surface of the housing 11 . The larger the value is, the larger the proportion of the first sub-region 11d is. The smaller it is, the smaller the proportion of the first sub-region 11d is.

[0144] In this embodiment, by setting the ratio of the length of the first sub-region 11d to the length of the large surface of the shell 11 to 0.2-0.6, and the wall thickness of the first sub-region 11d is greater than the wall thickness of the second sub-region 11e and the third sub-region 11f, that is, the ratio of the length of the maximum wall thickness in the thickened region 11c to the length of the large surface of the shell 11 is set to 0.2-0.6, so that the shell 11 has sufficient strength while reducing the weight and volume of the shell 11, reducing the material used in the shell 11, reducing the cost, and improving the energy density of the battery 100.

[0145] For some embodiments, please refer to Fig. 9 The length dimension of the second sub-region 11e is L3, wherein L3<L2, and 1mm≤L3≤0.5(L-L2-3mm).

[0146] That is to say, the length dimension L3 of the second sub-area 11e is greater than or equal to 1 mm, less than or equal to 0.5 times the value obtained by subtracting the length dimension L of the large surface of the shell 11 from the length dimension L2 of the first sub-area 11d and then subtracting 3 mm, and is less than the length dimension L2 of the first sub-area 11d.

[0147] In this embodiment, by setting the length of the second sub-region 11e to 1mm≤L3≤0.5 (L-L2-3mm), the outer shell 11 has sufficient strength while reducing the weight and volume of the outer shell 11, reducing the material used in the outer shell 11, reducing costs, and improving the energy density of the battery 100.

[0148] Exemplarily, the length dimension L5 of the third sub-region 11f is smaller than the length dimension L3 of the second sub-region 11e.

[0149] For some examples, see Fig. 9 The battery cell 10 is in a rectangular shape, at least one large surface of the shell 11 is provided with the thickened area 11c, the wall thickness of the other areas of the shell 11 except the thickened area 11c is T, and the wall thickness of the first sub-area 11d is T2, wherein, Alternatively, 0.5mm≤T2≤1.5mm.

[0150] The wall thickness of the first sub-region 11d in this embodiment is the same as the wall thickness of the thickened region 11c in the embodiment where the thickened region 11c is a region of equal wall thickness, that is, the same as T1, and therefore has the same beneficial effects, which will not be described in detail here.

[0151] For some examples, see Fig. 9 , the wall thickness of the second sub-region 11e is T3, wherein T<T3<2T. That is, the wall thickness of the second sub-region 11e is greater than the wall thickness of other regions of the shell 11 except the thickened region 11c, less than 2 times the wall thickness of other regions of the shell 11 except the thickened region 11c, and less than the wall thickness of the first sub-region 11d.

[0152] For example, 1.1T, 1.2T, 1.3T, 1.4T, 1.5T, 1.6T, 1.7T, 1.8T or 1.9T, etc.

[0153] In this embodiment, by setting the wall thickness of the second sub-region 11e to T<T3<2T and smaller than the wall thickness of the first sub-region 11d, the structural strength of the outer shell 11 is specifically strengthened, so that the outer shell 11 has sufficient strength, while reducing the weight and volume of the outer shell 11, reducing the material used in the outer shell 11, reducing costs, and improving the energy density of the battery 100.

[0154] For some embodiments, please refer to Fig. 9 , the wall thickness of the third sub-region 11f is T4, where T<T4<1.5T. That is, the wall thickness of the third sub-region 11f is greater than the wall thickness of other regions of the shell 11 except the thickened region 11c, less than 1.5 times the wall thickness of other regions of the shell 11 except the thickened region 11c, less than the wall thickness of the first sub-region 11d, and less than the wall thickness of the second sub-region 11e.

[0155] For example, 1.1T, 1.15T, 1.2T, 1.25T, 1.3T, 1.35T, 1.4T, 1.45T or 1.5T, etc.

[0156] In this embodiment, by setting the wall thickness of the third sub-region 11f to T<T4<1.5T and smaller than the wall thickness of the second sub-region 11e, the structural strength of the outer shell 11 is specifically strengthened, so that the outer shell 11 has sufficient strength, while reducing the weight and volume of the outer shell 11, reducing the material used for the outer shell 11, reducing costs, and improving the energy density of the battery 100.

[0157] For some examples, see Figures 6 to 8 The shell 11 also includes transition areas 11n disposed at both ends of the thickened area 11c, and the wall thickness of the transition area 11n gradually increases or decreases along the extension direction of the thickened area 11c. The length dimension of the large surface of the shell 11 is L, the wall thickness of the thickened area 11c is the same along the extension direction of the thickened area 11c, and the length dimension of the thickened area 11c is L1, and the length dimension of the inner side wall of the transition area 11n is L4, wherein L4<L-L1.

[0158] The inner side wall of the transition region 11 n is the side wall of the transition region 11 n that is away from the outer side wall of the housing 11 .

[0159] In this embodiment, transition regions 11n are provided at both ends of the thickened region 11c so that the thickened region 11c is smoothly connected to other regions of the housing 11, thereby improving the structural strength of the housing 11 and also providing an anti-scratch effect. In addition, by setting the length dimension of the inner side wall of the transition region 11n to L4<L-L1, the slope and length of the transition region 11n can be set.

[0160] For some examples, see Figures 6 to 8 The angle between the inner side wall of the transition area 11n and the inner side wall of the thickened area 11c is A, wherein 90°<A<180°, for example, 91°, 95°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170° or 179°, etc.

[0161] In this embodiment, the angle between the inner side wall of the transition area 11n and the inner side wall of the thickened area 11c is set to 90°<A<180°, thereby achieving the setting of the slope and length of the transition area 11n.

[0162] For some examples, see Figures 4 to 5The shape of the top cover 12 is consistent with the shape of the inner shell 11, and the gap between the top cover 12 and the shell 11 is t, wherein 0.05mm≤t≤0.3mm, for example, 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm or 0.3mm, etc.

[0163] In this embodiment, by setting the gap between the top cover 12 and the outer shell 11 to 0.05 mm-0.3 mm, it is beneficial to improve the assembly and welding performance of the top cover 12 and the outer shell 11.

[0164] In some embodiments, the top cover 12 and / or the housing 11 are made of aluminum.

[0165] It can be understood that when the material of the top cover 12 and / or the outer shell 11 is aluminum, the inner side wall of at least a portion of the outer shell 11 located at the opening 11b is thickened to form a thickened area 11c, and a connection area adapted to the thickened area 11c is formed at the edge of the top cover 12, and the connection area is connected to the thickened area 11c, thereby improving the structural strength of the connection between the outer shell 11 and the top cover 12, thereby improving the connection strength 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 improving the service life of the battery cell 10.

[0166] It should be noted that the length dimension L of the large surface of the shell 11, the length dimension L1 of the thickened area 11c, the length dimension L2 of the first sub-area 11d, the length dimension L3 of the second sub-area 11e, the length dimension L4 of the inner wall of the transition area 11n, the length dimension L5 of the third sub-area 11f, the wall thickness T of other areas of the shell 11 except the thickened area 11c, the wall thickness T1 of the thickened area 11c, the wall thickness T2 of the first sub-area 11d, the wall thickness T3 of the second sub-area 11e, the wall thickness T4 of the third sub-area 11f, the angle A between the inner wall of the transition area 11n and the inner wall of the thickened area 11c, the gap t between the top cover 12 and the shell 11 and other values ​​can be obtained by testing and calculation using instruments such as a high-precision thickness gauge, an angle measuring instrument, and a vernier caliper at room temperature when the top cover 12 is not assembled.

[0167] The battery cell 10 of the present application is further described below in conjunction with specific test examples.

[0168] The test sample of the embodiment of the present application: the inner wall of at least part of the area of ​​the shell 11 located at the opening 11b is thickened to form a thickened area 11c, and the edge of the top cover 12 is formed with a connecting area adapted to the thickened area 11c, and the connecting area is connected to the thickened area 11c.

[0169] By performing charge and discharge cycle experiments on the test samples and the control group of the embodiment of the present application, and recording the number of cycles, the number of cycles of the five control groups of the embodiment of the present application are 2015, 2336, 2165, 2380, and 2217, respectively, and the average number of cycles of the five control groups of the embodiment of the present application is 2222 times. The number of cycles of the five test samples of the control group are 2869, 2695, 2711, 2742, and 2796, respectively, and the average number of cycles of the five test samples of the embodiment of the present application is 2762 times. The average value of the test samples of the embodiment of the present application is higher than that of the control group. The average value of the control group increased by 24.3%. When the electrode assembly cyclically expands and generates gas during charge and discharge, force will be generated on 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 the number of cycles of the control group. In other words, the battery cell 10 provided in the embodiment of the present application improves the structural strength of the outer shell 11, 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, improves fatigue performance, reduces the overall weld thermal deformation strain, and increases the service life of the battery cell 10.

[0170] 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.

[0171] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application are included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that: include: A housing having a receiving space and an opening; A top cover, a sealing cover is arranged at the opening; An electrode assembly is disposed in the accommodation space; The inner wall of at least a part of the outer shell at the opening is thickened to form a thickened area, and a connection area adapted to the thickened area is formed at the edge of the top cover, and the connection area is connected to the thickened area.

2. The battery cell according to claim 1, characterized in that: The thickened area extends along an edge of the opening.

3. The battery cell according to claim 1, characterized in that: The wall thickness of the thickened area is the same along the extension direction of the thickened area; or, the wall thickness of the thickened area increases along the extension direction of the thickened area; or, the wall thickness of the thickened area first increases and then decreases along the extension direction of the thickened area.

4. The battery cell according to claim 1, characterized in that: The thickened region includes a plurality of sub-regions arranged in sequence along the extension direction of the thickened region, each sub-region has the same wall thickness, and any two adjacent sub-regions have different wall thicknesses.

5. The battery cell according to claim 1, characterized in that: The battery cell is in a rectangular parallelepiped shape, and at least one large surface of the housing is provided with the thickened area; or, The battery cell is cylindrical in shape, and the thickened area is provided on at least a portion of the housing.

6. The battery cell according to claim 5, characterized in that: The length dimension of the large surface of the shell is L, and the length dimension of the thickened area is L1, wherein, 7. The battery cell according to claim 1, characterized in that: The wall thickness of the shell in other areas except the thickened area is T, the wall thickness of the thickened area is the same along the extension direction of the thickened area, and the wall thickness of the thickened area is T1, wherein, 8. The battery cell according to claim 4, characterized in that: The thickened area includes a first sub-area, two second sub-areas and two third sub-areas, the two second sub-areas are respectively connected to the two sides of the first sub-area, the two third sub-areas are respectively connected to the two second sub-areas, and the wall thicknesses of the first sub-area, the second sub-area and the third sub-area decrease successively.

9. The battery cell according to claim 8, characterized in that: The battery cell is in a rectangular shape, at least one large surface of the shell is provided with the thickened area, the length dimension of the large surface of the shell is L, and the length dimension of the first sub-area is L2, wherein, 10. The battery cell according to claim 9, characterized in that: The length dimension of the second sub-region is L3, wherein L3<L2, and 1mm≤L3≤0.5(L-L2-3mm).

11. The battery cell according to claim 8, characterized in that: The battery cell is in a rectangular shape, at least one large surface of the shell is provided with the thickened area, the wall thickness of other areas of the shell except the thickened area is T, the wall thickness of the first sub-area is T2, wherein, Alternatively, 0.5mm≤T2≤1.5mm.

12. The battery cell according to claim 11, characterized in that: The wall thickness of the second sub-region is T3, wherein T<T3<2T; and / or, The wall thickness of the third sub-region is T4, wherein T<T4<1.5T.

13. The battery cell according to claim 5, characterized in that: The shell further comprises transition regions arranged at both ends of the thickened region, and the wall thickness of the transition regions gradually increases or decreases along the extension direction of the thickened region; The length dimension of the large surface of the shell is L, the wall thickness of the thickened area is the same along the extension direction of the thickened area, and the length dimension of the thickened area is L1, and the length dimension of the inner side wall of the transition area is L4, wherein L4<L-L1; and / or, The included angle between the inner side wall of the transition area and the inner side wall of the thickened area is A, wherein 90<A<180.

14. The battery cell according to any one of claims 6 to 13, characterized in that: The top cover and / or the housing are made of aluminum.

15. A battery, characterized in that: The invention comprises at least one battery cell according to any one of claims 1 to 14.

16. An electrical device, characterized in that: The battery according to claim 15 is used to provide electrical energy to the electrical device.

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