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. An inner side wall of at least part of the area of the housing located at the opening is thickened to form a thickened area, an edge of the top cover is formed with a connecting area matching the thickened area, and the connecting area is connected with the thickened area. The inner side wall of at least part of the area of the housing located at the opening is thickened to form the thickened area, thereby increasing the structural strength of the connection between the housing and the top cover, so as to increase the connection strength of the housing and the top cover, 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, improving the expansion resistance of a casing, and increasing the service life of the battery cell.

Description

A battery cell, a battery, and an electrical device. Technical Field

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

[0002] This section is intended to provide background or context for embodiments of this application. The description herein is not intended to imply that it is prior art simply because it is included in this section.

[0003] In battery manufacturing, after placing the bare cell into a casing and closing the top cover, a casing-equipped cell is obtained. After the bare cell is placed in the casing, the casing and top cover need to be welded together. In related technologies, the expansion of the bare cell during cycles and the generation of gas during charging and discharging can cause cracks at the connection between the casing and the top cover, potentially leading to failure of the connection structure between them.

[0004] Summary of the Invention

[0005] In view of this, the embodiments of this application aim to provide a battery cell, a battery, and an electrical device that can improve the problem of connection structure failure between the casing and the top cover, and improve the service life of the battery cell.

[0006] To achieve the above objectives, a first aspect of this application provides a battery cell, comprising:

[0007] The outer casing has a storage space and openings;

[0008] A top cover and a sealing cover are provided at the opening;

[0009] Electrode assembly, disposed within the receiving space;

[0010] The inner wall of at least a portion of the outer shell at the opening is thickened to form a thickened region, and the edge of the top cover has a connecting region adapted to the thickened region, the connecting region being connected to the thickened region.

[0011] The battery cell provided in this application embodiment thickens the inner wall of at least a portion of the opening of the outer casing to form a thickened region. The edge of the top cover has a connection region adapted to the thickened region. The connection region is connected to the thickened region, thereby improving the structural strength at the connection between the outer casing and the top cover, thus improving the connection strength between the outer casing and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer casing and the top cover, improving the failure problem of the connection structure between the outer casing and the top cover, improving the expansion resistance of the casing, and increasing the service life of the battery cell.

[0012] In some embodiments, the thickened region extends along the edge of the opening.

[0013] In this embodiment, by extending the thickened area along the edge of the opening, the stress on the outer shell can be made more uniform.

[0014] 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.

[0015] In this way, the wall thickness of the thickened area can be designed specifically according to the needs, that is, according to the different stresses in different areas of the casing, thereby improving the structural strength of the casing in a targeted manner. While ensuring sufficient connection strength at the connection between the top cover and the casing, the weight and volume of the battery cell are reduced, the amount of material used in the casing is reduced, the cost is lowered, and the overall performance of the battery is improved.

[0016] In some embodiments, the thickened region includes multiple sub-regions arranged sequentially along the extension direction of the thickened region, each sub-region having the same wall thickness, and any two adjacent sub-regions having different wall thicknesses.

[0017] In this embodiment, by setting the thickened area to include multiple sub-areas, which increase in a stepped manner, or by increasing in a stepped manner first and then decreasing, the wall thickness of the thickened area can be designed specifically according to the requirements, i.e., according to the different stresses experienced by different areas of the casing. This can specifically improve the structural strength of the casing, ensuring sufficient connection strength between the top cover and the casing while reducing the weight and volume of the battery cells, reducing the amount of material used in the casing, lowering costs, and improving the overall performance of the battery.

[0018] In some embodiments, the battery cell is rectangular, and at least one large surface of the casing is provided with the thickened area.

[0019] In some embodiments, the battery cell is cylindrical, and at least a portion of the outer casing has the thickened region.

[0020] In some embodiments, the length dimension of the large surface of the outer shell is L, and the length dimension of the thickened region is L1, wherein,

[0021] 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 outer shell to 0.2-0.8, the outer shell has sufficient strength while reducing its weight and volume, reducing the amount of material used, lowering costs, and increasing the energy density of the battery.

[0022] In some embodiments, the wall thickness of the outer shell, excluding 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...

[0023] In this embodiment, by setting the ratio between the difference between the wall thickness of the thickened area and the wall thickness of other areas of the outer casing (excluding the thickened area) and the wall thickness of other areas of the outer casing (excluding the thickened area) to 0.2-2, the outer casing can have sufficient strength while reducing its weight and volume, reducing the amount of material used, lowering costs, and increasing the energy density of the battery.

[0024] In some embodiments, the wall thickness of the thickened region is T1, wherein 0.5mm ≤ T1 ≤ 1.5mm.

[0025] In this embodiment, by setting the wall thickness of the thickened area to 0.5mm-1.5mm, the casing has sufficient strength while reducing its weight and volume, reducing the amount of material used, lowering costs, and increasing the energy density of the battery.

[0026] In some embodiments, the thickened region includes a first sub-region, two second sub-regions, and two third sub-regions. The two second sub-regions are respectively connected to both sides of the first sub-region, and the two third sub-regions are respectively connected to the two second sub-regions. The wall thickness of the first sub-region, the second sub-region, and the third sub-region decreases sequentially.

[0027] In this embodiment, by designing the wall thickness of the thickened area to first increase in a stepwise manner and then decrease in a stepwise manner, it is beneficial to design the wall thickness of the thickened area in a targeted manner, thereby improving the structural strength of the shell. While ensuring sufficient connection strength at the connection between the top cover and the shell, the weight and volume of the battery cell are reduced, the amount of material used in the shell is reduced, the cost is lowered, and the overall performance of the battery is improved.

[0028] In some embodiments, the battery cell is rectangular, and at least one large surface of the outer casing has the thickened region. The length of the large surface of the outer casing is L, and the length of the first sub-region is L2.

[0029] In this embodiment, by setting the ratio of the length of the first sub-region to the length of the large surface of the outer shell to 0.2-0.6, and the wall thickness of the first sub-region being greater than the wall thickness of the second and third sub-regions, that is, setting the ratio of the length of the maximum wall thickness in the thickened region to the length of the large surface of the outer shell to 0.2-0.6, the outer shell has sufficient strength while reducing the weight and volume of the outer shell, reducing the amount of material used in the outer shell, lowering the cost, and increasing the energy density of the battery.

[0030] In some embodiments, the length of the second sub-region is L3, where L3 < L2, and 1 mm ≤ L3 ≤ 0.5 (L - L2 - 3 mm).

[0031] In this embodiment, by setting the length of the second sub-region to 1mm≤L3≤0.5(L-L2-3mm), the shell has sufficient strength while reducing its weight and volume, reducing the amount of material used, lowering costs, and increasing the energy density of the battery.

[0032] In some embodiments, the battery cell is rectangular, at least one large surface of the outer casing has the thickened region, the wall thickness of the other regions of the outer casing excluding the thickened region is T, and the wall thickness of the first sub-region is T2, wherein... Alternatively, 0.5mm≤T2≤1.5mm.

[0033] In some embodiments, the wall thickness of the second sub-region is T3, where T < T3 < 2T.

[0034] In this embodiment, the wall thickness of the second sub-region is set to T < T3 < 2T, and is less than the wall thickness of the first sub-region, so as to specifically strengthen the structural strength of the shell.

[0035] In some embodiments, the wall thickness of the third sub-region is T4, where T < T4 < 1.5T.

[0036] In this embodiment, the wall thickness of the third sub-region is set to T < T4 < 1.5T, and is less than the wall thickness of the second sub-region, so as to specifically strengthen the structural strength of the shell.

[0037] In some embodiments, the outer casing further includes transition regions disposed at both ends of the thickened region, wherein the wall thickness of the transition regions gradually increases or decreases along the extension direction of the thickened region;

[0038] The length dimension of the large surface of the outer shell is L, the wall thickness of the thickened region is the same along the extension direction of the thickened region, and the length dimension of the thickened region is L1. The length dimension of the inner sidewall of the transition region is L4, where L4 < L - L1.

[0039] In this embodiment, transition regions are provided at both ends of the thickened area to ensure a smooth connection between the thickened area and other areas of the outer shell. This not only improves the structural strength of the outer shell but also provides scratch protection. Furthermore, by setting the length of the inner sidewall of the transition region to L4 < L - L1, the slope and length of the transition region can be controlled.

[0040] In some embodiments, the angle between the inner wall of the transition region and the inner wall of the thickened region is A, where 90 < A < 180.

[0041] In this embodiment, the slope and length of the transition region are set by setting the included angle between the inner wall of the transition region and the inner wall of the thickened region to 90° < A < 180°.

[0042] In some embodiments, the top cover and / or the outer shell is made of aluminum.

[0043] A second aspect of this application provides a battery comprising at least one of the battery cells described above.

[0044] The battery provided in this application embodiment includes at least one battery cell of this application embodiment. By thickening the inner sidewall of at least a portion of the opening of the outer casing to form a thickened region, and forming a connection region adapted to the thickened region on the edge of the top cover, the connection region is connected to the thickened region. This improves the structural strength at the connection between the outer casing and the top cover, thereby increasing the connection strength between the outer casing and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer casing and the top cover, improving the failure problem of the connection structure between the outer casing and the top cover, improving the expansion resistance of the casing, and increasing the service life of the battery cell.

[0045] A third aspect of this application provides an electrical device including the battery described above, the battery being used to provide electrical energy to the electrical device.

[0046] The electrical device provided in this application includes a battery, which includes at least one battery cell according to this application embodiment. By thickening the inner wall of at least a portion of the opening of the outer casing to form a thickened region, and forming a connection region adapted to the thickened region on the edge of the top cover, the connection region is connected to the thickened region. This improves the structural strength at the connection between the outer casing and the top cover, thereby increasing the connection strength between the outer casing and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer casing and the top cover, improving the failure problem of the connection structure between the outer casing and the top cover, improving the expansion resistance of the casing, and increasing the service life of the battery cell. Attached Figure Description

[0047] Figure 1 is a structural schematic diagram of a vehicle provided in an embodiment of this application;

[0048] Figure 2 is a three-dimensional exploded view of a battery provided in an embodiment of this application;

[0049] Figure 3 is a top view of a battery cell provided in an embodiment of this application;

[0050] Figure 4 is a cross-sectional view of Figure 3 along the AA direction;

[0051] Figure 5 is an enlarged view of point B in Figure 4;

[0052] Figure 6 is a schematic diagram of the structure of the outer shell provided in the first embodiment of this application;

[0053] Figure 7 is a top view of the outer casing shown in Figure 6;

[0054] Figure 8 is an enlarged view of point C in Figure 7;

[0055] Figure 9 is a schematic diagram of the structure of the outer shell provided in the second embodiment of this application. Detailed Implementation

[0056] It should be noted that, unless otherwise specified, the embodiments and technical features in the embodiments of this application can be combined with each other, and the detailed descriptions in the specific implementation should be understood as explanations of the purpose of this application and should not be regarded as undue limitations on this application.

[0057] 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 pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having” and any variations thereof are intended to cover non-exclusive inclusion.

[0058] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0059] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0060] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects are in an "or" relationship.

[0061] In the description of the embodiments of this 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", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0062] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0063] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0064] With the development of clean energy, more and more devices are using electricity as their driving force, leading to the rapid development of power batteries, such as lithium-ion batteries, which can store a large amount of electrical energy and can be repeatedly charged and discharged. These power batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but are also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields.

[0065] With the government's strong promotion of new energy vehicles, they have ushered in a golden opportunity for development. Vehicle safety and stability have always been top concerns. Therefore, improving the safety of new energy vehicles will be one of the key factors determining their rapid popularization. Improving battery safety is a crucial way to enhance the overall safety of new energy vehicles.

[0066] In this application, the battery cell may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto.

[0067] The battery mentioned in the embodiments of this application refers to a single physical module comprising one or more battery cells to provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or a battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0068] A battery cell includes an electrode assembly and an electrolyte. The electrode assembly consists of a positive electrode, a negative electrode, and a separator. The battery cell primarily functions by the movement of metal ions between the positive and negative electrodes. The positive electrode includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector, and the uncoated positive current collector protrudes beyond the coated one, serving as the positive electrode tab. Taking a lithium-ion battery as an example, the positive current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode includes a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector, and the uncoated negative current collector protrudes beyond the coated one, serving as the negative electrode tab. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. To ensure that a large current can pass through without melting, there are multiple positive electrode tabs stacked together, and there are multiple negative electrode tabs stacked together. The separator can be made of PP (polypropylene) or PE (polyethylene), etc.

[0069] For example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0070] For example, the positive electrode current collector can be a metal foil or a composite current collector. For instance, the metal foil can be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, nickel, or titanium. The composite current collector may include a polymer substrate 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 substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0071] For example, the negative electrode can be a negative electrode sheet, which may include a negative electrode current collector.

[0072] For example, the negative electrode current collector can be a metal foil or a composite current collector. For instance, as a metal foil, it can be 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.

[0073] For example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0074] Exemplarily, the negative electrode active material may be any negative electrode active material known in the art for use in batteries. 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, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional 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.

[0075] The battery cell also includes a packaging film and a casing. The packaging film covers the outside of the electrode assembly, and the casing encapsulates the electrode assembly covered with the packaging film to form the battery cell. The packaging film can be Mylar film, and the casing can be an aluminum shell. After the electrode assembly is wound and formed, the Mylar film and casing are encapsulated through a Mylar film wrapping process and a casing insertion process. The Mylar film serves to seal and protect the electrode assembly, and it effectively insulates the electrode assembly and casing from each other, preventing internal short circuits within the battery cell. The casing provides protection.

[0076] Exemplarily, the housing includes a top cover and an outer shell, the housing having an opening, the top cover closing the opening to form a sealed space for accommodating substances such as electrode assemblies and electrolytes. The housing may have one or more openings. The top cover may also have one or more openings.

[0077] For example, the housing is provided with at least one electrode terminal, which is electrically connected to the tab of the electrode assembly. The electrode terminal can be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal can be located on the top cover or on the outer casing.

[0078] For example, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cell.

[0079] For example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. There are no particular limitations in the embodiments of this application.

[0080] For example, the battery cell also includes a pressure relief structure, which can be provided on the top cover or the outer casing, to release the internal pressure or temperature of the battery cell.

[0081] The development of battery technology must take into account multiple design factors, such as energy density, discharge capacity, charge-discharge rate and other performance parameters. In addition, battery reliability also needs to be considered.

[0082] In related technologies, when gas is generated during the cyclic expansion of the electrode assembly and the charging and discharging process, it exerts a force on the outer shell and the top cover, causing the outer shell to deform outward. This stretches the connection structure between the outer shell and the top cover, leading to fatigue cracking at the connection point and potentially causing the connection structure between the outer shell and the top cover to fail.

[0083] To address the issue of connection structure failure between the outer casing and the top cover, and to extend the lifespan of the battery cell, this application provides a battery cell comprising an outer casing, a top cover, and an electrode assembly. The outer casing has a receiving space and an opening. A sealing cap is disposed at the opening. The electrode assembly is disposed within the receiving space. Specifically, at least a portion of the inner wall of the outer casing at the opening is thickened to form a thickened region, and the edge of the top cover has a connection region adapted to the thickened region, the connection region being connected to the thickened region. This improves the pressure resistance and long-term reliability of the weld, and enhances the assembly and weldability of the top cover and the outer casing.

[0084] The battery cell provided in this application embodiment thickens the inner wall of at least a portion of the opening of the outer casing to form a thickened region. The edge of the top cover has a connection region adapted to the thickened region. The connection region is connected to the thickened region, thereby improving the structural strength at the connection between the outer casing and the top cover, thus improving the connection strength between the outer casing and the top cover, reducing the risk of fatigue cracking of the connection structure between the outer casing and the top cover, improving the failure problem of the connection structure between the outer casing and the top cover, improving the expansion resistance of the casing, and increasing the service life of the battery cell.

[0085] The technical solutions described in the embodiments of this application are applicable to batteries and electrical devices that use batteries.

[0086] The battery mentioned in the embodiments of this application refers to a single physical module comprising at least one battery cell provided in the embodiments of this application. One or more battery cells provide higher voltage and capacity. For example, the battery mentioned in this application may include a battery module or battery pack. A battery generally includes a housing for encapsulating one or more battery cells. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0087] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0088] It should be noted that the technical solutions described in the embodiments of this application are not limited to the batteries and electrical devices described above, but can also be applied to all batteries including housings and electrical devices using batteries. However, for the sake of brevity, the following embodiments are all described using electric vehicles as examples.

[0089] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 provided in some embodiments of this application. The vehicle 1000 may contain a controller 200, a motor 300, and a battery 100. The controller 200 controls the battery 100 to supply power to the motor 300. For example, the battery 100 may be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, it can serve as the operating power source for the vehicle 1000's electrical system, such as meeting the power requirements for starting, navigation, and operation. In another embodiment of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000 but also as the driving power source, replacing or partially replacing fuel or natural gas to provide driving power to the vehicle 1000.

[0090] To meet different power demands, battery 100 may include multiple battery cells 10, where each battery cell 10 is the smallest unit that makes up a battery module or battery pack 100. Multiple battery cells 10 can be connected in series, parallel, or in a hybrid configuration, where some cells are connected in series and others in parallel. Multiple battery cells 10 can be directly connected in series, parallel, or in a hybrid configuration and then housed within a casing. Alternatively, battery 100 can be composed of multiple battery cells 10 first connected in series, parallel, or in a hybrid configuration to form a battery module, and then these modules can be connected in series, parallel, or in a hybrid configuration to form a whole housed within a casing. Battery 100 may also include other structures, such as a busbar for electrical connection between the multiple battery cells 10. Each battery cell 10 can be a secondary or primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. Battery cells 10 can be cylindrical, flat, cuboid, or other shapes.

[0091] Referring to Figure 2, the battery 100 includes a battery case 20 and at least one battery cell 10, with the battery cell 10 disposed within the mounting space of the battery case 20.

[0092] The battery box 20 can be a simple three-dimensional structure such as a single cuboid, cylinder, or sphere, or it can be a complex three-dimensional structure composed of simple three-dimensional structures such as cuboids, cylinders, or spheres. The battery box 20 can be made of alloy materials such as aluminum alloy or iron alloy, polymer materials such as polycarbonate or polyisocyanurate foam, or composite materials such as glass fiber and epoxy resin.

[0093] The battery box 20 is used to accommodate the battery cell 10, and the battery box 20 can have various structures. In some embodiments, the battery box 20 may include a first box portion 21 and a second box portion 22, which overlap each other, and together define an installation space for accommodating the battery cell 10. The second box portion 22 may be a hollow structure with one end open, and the first box portion 21 may be a plate-like structure, with the first box portion 21 covering the open side of the second box portion 22 to form a battery box 20 with an installation space; alternatively, both the first box portion 21 and the second box portion 22 may be hollow structures with one side open, with the open side of the first box portion 21 covering the open side of the second box portion 22 to form a battery box 20 with an installation space. Of course, the first box portion 21 and the second box portion 22 can have various shapes, such as cylinders, cuboids, etc.

[0094] To improve the sealing performance after the first housing part 21 and the second housing part 22 are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 21 and the second housing part 22.

[0095] Assuming that the first box section 21 covers the top of the second box section 22, the first box section 21 can also be called the upper box cover, and the second box section 22 can also be called the lower box cover.

[0096] In battery 100, there can be one or more battery cells 10. If there are multiple battery cells 10, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 10 are connected in both series and parallel. Multiple battery cells 10 can be directly connected in series, in parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 10 is housed in battery box 20. Alternatively, multiple battery cells 10 can first be connected in series, in parallel, or in a mixed manner to form a battery module, and then multiple battery modules can be connected in series, in parallel, or in a mixed manner to form a whole assembly, which is then housed in battery box 20.

[0097] 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., and this application embodiment is not limited to this. The battery cell 10 may be cylindrical, flat, cuboid, or other shapes, etc., and this application embodiment is not limited to this. The battery cell 10 is generally divided into three types according to the packaging method: cylindrical battery cell, square battery cell, and pouch battery cell, and this application embodiment is not limited to this.

[0098] This application provides a battery cell, as shown in 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 disposed at the opening 11b. The electrode assembly is disposed within the receiving space 11a. At least a portion of the inner wall of the housing 11 at the opening 11b is thickened to form a thickened region 11c. The edge of the top cover 12 has a connection region adapted to the thickened region 11c, and the connection region is connected to the thickened region 11c.

[0099] Here, the shell can be cylindrical, flat, cuboid, or other shapes.

[0100] It should be noted that, in the embodiments of this application, the height direction of the outer shell 11 is the direction in which the shell enters the receiving space 11a from the opening 11b, or the opposite direction. When the outer shell 11 is cylindrical, the height direction of the outer shell 11 is the axial direction of the outer shell 11.

[0101] 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 is used. That is, the top cover 12 and the outer shell 11 are welded to each other in the area where the opening 11b is located.

[0102] The edge of the top cover 12 has a connection area that is adapted to the thickened region 11c, which helps to ensure the reliability of the connection between the connection area and the thickened region 11c.

[0103] The top cover 12 is generally perpendicular to the side of the outer shell 11. The outer shell 11 deforms outward, and a shear force parallel to the top cover 12 is generated at the connection between the outer shell 11 and the top cover 12. The structural strength of the outer shell 11 at the opening 11b is improved by providing a thickened region 11c on the inner wall of at least a portion of the outer shell 11.

[0104] The battery cell 10 provided in this application embodiment thickens the inner wall of at least a portion of the outer casing 11 at the opening 11b to form a thickened region 11c. The edge of the top cover 12 has a connection region adapted to the thickened region 11c. The connection region is connected to the thickened region 11c. This improves the structural strength at the connection between the outer casing 11 and the top cover 12, thereby increasing the connection strength between the outer casing 11 and the top cover 12, reducing the risk of fatigue cracking of the connection structure between the outer casing 11 and the top cover 12, improving the failure problem of the connection structure between the outer casing 11 and the top cover 12, improving the expansion resistance of the casing, and increasing the service life of the battery cell 10.

[0105] In some embodiments, see Figures 6 and 9, the thickened region 11c extends along the edge of the opening 11b.

[0106] Here, the thickened region 11c extends along the edge of the opening 11b, that is, the thickened region 11c extends along the edge of the top cover 12. In other words, when projected onto a plane parallel to the top cover 12, the outline shape of the center line of the thickened region 11c along the extension direction is exactly the same as or approximately the same as the edge shape of the opening 11b.

[0107] The inner wall of at least a portion of the outer casing 11 at the opening 11b is thickened to form a thickened region 11c. This thickened region 11c can be formed in a portion of the outer casing 11 at the opening 11b, or it can be formed in the entire area of ​​the outer casing 11 at the opening 11b. In other words, the outer casing 11 is provided with a thickened region 11c that surrounds the opening 11b.

[0108] In this embodiment, by extending the thickened region 11c along the edge of the opening 11b, the stress on the outer shell 11 can be made more uniform.

[0109] For example, when the battery cell 10 is cylindrical, at least a portion of the housing 11 is provided with a thickened region 11c.

[0110] The top cover 12 may have a thickened area 11c extending along the edge of the top cover 12, or the thickened area 11c may be partially surrounding the top cover 12.

[0111] For example, when the battery cell 10 is cuboid in shape, at least one large surface of the casing 11 is provided with a thickened region 11c.

[0112] Here, the thickened region 11c may be formed in a partial or complete area of ​​the large surface located at the opening 11b. Of course, the thickened region 11c may also be formed in a partial or complete area of ​​the small surface located at the opening 11b. In some embodiments, the thickened region 11c is formed in the partial areas of the two large surfaces of the outer shell 11 located at the opening 11b, while the thickened region 11c is not formed on the two small surfaces.

[0113] In this embodiment, by providing a thickened region 11c on at least one large surface of the outer shell 11, it is beneficial to improve the structural strength of the outer shell 11, 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.

[0114] It should be noted that the specific structure of the thickened region 11c is not limited here.

[0115] In some embodiments, referring to FIG6, the wall thickness of the thickened region 11c is the same along the extension direction of the thickened region 11c.

[0116] Here, the distance between the thickened region 11c and the outer wall of the outer shell 11 can be the same at any two positions in its extension direction, so that the force near the thickened region 11c can be more uniform.

[0117] In other embodiments, the wall thickness of the thickened region 11c increases along the extension direction of the thickened region 11c.

[0118] The increase in the wall thickness of the thickened region 11c along the extension direction of the thickened region 11c means that the wall thickness of the thickened region 11c can increase gradually or in a step-like manner along the extension direction of the thickened region 11c.

[0119] In this way, the wall thickness of the thickened area 11c can be designed specifically according to the needs, that is, according to the different stresses in different areas of the outer casing 11, thereby improving the structural strength of the outer casing 11. While ensuring sufficient connection strength at the connection between the top cover 12 and the outer casing 11, the weight and volume of the battery cell 10 are reduced, the materials used in the outer casing 11 are reduced, the cost is lowered, and the overall performance of the battery 100 is improved.

[0120] In some other embodiments, please refer to Figure 9, the wall thickness of the thickened region 11c first increases and then decreases along the extension direction of the thickened region 11c.

[0121] The phrase "the wall thickness of the thickened region 11c increases first and then decreases along the extension direction of the thickened region 11c" means that the wall thickness of the thickened region 11c can gradually increase first and then gradually decrease along the extension direction of the thickened region 11c, or it can increase first and then decrease in a step-like manner.

[0122] In this way, the wall thickness of the thickened area 11c can be designed specifically according to the needs, that is, according to the different stresses in different areas of the outer casing 11, thereby improving the structural strength of the outer casing 11. While ensuring sufficient connection strength at the connection between the top cover 12 and the outer casing 11, the weight and volume of the battery cell 10 are reduced, the materials used in the outer casing 11 are reduced, the cost is lowered, and the overall performance of the battery 100 is improved.

[0123] In some embodiments, referring to Figure 9, the thickened region 11c includes multiple sub-regions arranged sequentially along the extension direction of the thickened region 11c. Each sub-region has the same wall thickness, and the wall thicknesses of any two adjacent sub-regions are different. That is, the multiple sub-regions increase in a stepped manner, or the multiple sub-regions first increase and then decrease in a stepped manner.

[0124] Each sub-region has the same wall thickness, meaning that each sub-region is a region with equal wall thickness.

[0125] In this embodiment, by setting the thickened region 11c to include multiple sub-regions, which increase in a stepped manner, or which first increase and then decrease in a stepped manner, the wall thickness of the thickened region 11c can be designed specifically according to the requirements, i.e., according to the different stresses on different regions of the outer shell 11. This can specifically improve the structural strength of the outer shell 11, ensuring sufficient connection strength at the connection between the top cover 12 and the outer shell 11, while reducing the weight and volume of the battery cell 10, reducing the materials used in the outer shell 11, lowering costs, and improving the overall performance of the battery 100.

[0126] In some embodiments, referring to Figure 6, the length dimension of the large surface of the outer shell 11 is L, and the length dimension of the thickened region 11c is L1, wherein, For example, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8, etc.

[0127] here, This refers to the ratio of the length of the thickened area 11c on the main surface to the length of the main surface of the outer shell 11. The larger the value, the greater the proportion of the thickened region 11c. The smaller the value, the smaller the proportion of the thickened area 11c.

[0128] 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 outer shell 11 to 0.2-0.8, the outer shell 11 is made strong enough while reducing its weight and volume, reducing the amount of material used in the outer shell 11, lowering the cost, and increasing the energy density of the battery 100.

[0129] In some embodiments, referring to Figure 6, the wall thickness of the outer shell 11, excluding the thickened region 11c, is T. The wall thickness of the thickened region 11c is the same along its extension direction, and the wall thickness of the thickened region 11c is T1. 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.

[0130] The wall thickness of the thickened region 11c is the same along the extension direction of the thickened region 11c, that is, the thickened region 11c in this embodiment is a region with equal wall thickness.

[0131] here, It refers to the ratio between the difference between the wall thickness of the thickened region 11c and the wall thickness of the other regions of the outer shell 11 excluding the thickened region 11c, and the wall thickness of the other regions of the outer shell 11 excluding the thickened region 11c. The larger the value, the greater the increase in wall thickness of the thickened region 11c relative to other regions of the outer shell 11 besides the thickened region 11c. The smaller the value, the smaller the increase in wall thickness of the thickened region 11c relative to other regions of the outer shell 11 other than the thickened region 11c.

[0132] In this embodiment, by setting the ratio between the difference between the wall thickness of the thickened region 11c and the wall thickness of other regions of the outer shell 11 excluding the thickened region 11c to 0.2-2, the outer shell 11 can have sufficient strength while reducing the weight and volume of the outer shell 11, reducing the material used in the outer shell 11, lowering the cost, and increasing the energy density of the battery 100.

[0133] In some embodiments, referring to Figure 6, the wall thickness of the thickened region 11c is T1, where 0.5mm ≤ T1 ≤ 1.5mm. For example, it can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, or 1.5mm, etc.

[0134] In this embodiment, by setting the wall thickness of the thickened region 11c to 0.5mm-1.5mm, the outer casing 11 has sufficient strength while reducing its weight and volume, reducing the amount of material used in the outer casing 11, lowering costs, and increasing the energy density of the battery 100.

[0135] In some embodiments, please refer to FIG9, the thickened region 11c includes a first sub-region 11d, two second sub-regions 11e and two third sub-regions 11f. The two second sub-regions 11e are respectively connected to both sides of the first sub-region 11d, and the two third sub-regions 11f are respectively connected to the two second sub-regions 11e. The wall thickness of the first sub-region 11d, the second sub-region 11e and the third sub-region 11f decreases sequentially.

[0136] In other words, 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 arranged sequentially along the extension direction of the thickened region 11c.

[0137] The wall thickness of the first sub-region 11d, the second sub-region 11e, and the third sub-region 11f decreases sequentially. In other words, the wall thickness of the thickened region 11c is stepped, meaning that the wall thickness of the thickened region 11c first increases and then decreases.

[0138] Here, the battery cell 10 can be cylindrical or rectangular.

[0139] Taking a rectangular battery cell 10 as an example, the thickened area 11c can be located in the middle of the large surface of the outer casing 11.

[0140] In this embodiment, by designing the wall thickness of the thickened region 11c to first increase in a stepwise manner and then decrease in a stepwise manner, it is beneficial to design the wall thickness of the thickened region 11c in a targeted manner, thereby improving the structural strength of the outer shell 11. While ensuring sufficient connection strength at the connection between the top cover 12 and the outer shell 11, the weight and volume of the battery cell 10 are reduced, the materials used in the outer shell 11 are reduced, the cost is lowered, and the overall performance of the battery 100 is improved.

[0141] In some embodiments, referring to Figure 9, the battery cell 10 is rectangular, and at least one large surface of the casing 11 is provided with a thickened region 11c. The length dimension of the large surface of the casing 11 is L, and the length dimension of the first sub-region 11d is L2. For example, 0.2, 0.3, 0.4, 0.5, or 0.6, etc.

[0142] here, This refers to the ratio of the length of the first sub-region 11d to the length of the large surface of the outer shell 11. The larger the value, the greater the proportion of the first sub-region 11d. The smaller the value, the smaller the proportion of the first sub-region 11d.

[0143] 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 outer shell 11 to 0.2-0.6, and the wall thickness of the first sub-region 11d being greater than the wall thickness of the second sub-region 11e and the third sub-region 11f, that is, setting the ratio of the length of the maximum wall thickness in the thickened region 11c to the length of the large surface of the outer shell 11 to 0.2-0.6, the outer shell 11 is made strong enough while reducing the weight and volume of the outer shell 11, reducing the material used in the outer shell 11, reducing costs, and increasing the energy density of the battery 100.

[0144] In some embodiments, please continue to refer to Figure 9, the length dimension of the second sub-region 11e is L3, where L3 < L2, and 1mm ≤ L3 ≤ 0.5(L-L2-3mm).

[0145] In other words, the length dimension L3 of the second sub-region 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 L2 of the first sub-region 11d from the length dimension L of the large surface of the outer shell 11, and then subtracting 3 mm, and is less than the length dimension L2 of the first sub-region 11d.

[0146] In this embodiment, by setting the length of the second sub-region 11e to 1mm≤L3≤0.5(L-L2-3mm), the outer casing 11 is made strong enough while reducing its weight and volume, reducing the amount of material used in the outer casing 11, lowering the cost, and increasing the energy density of the battery 100.

[0147] For example, the length dimension L5 of the third sub-region 11f is smaller than the length dimension L3 of the second sub-region 11e.

[0148] In some embodiments, referring to Figure 9, the battery cell 10 is rectangular, and at least one large surface of the outer casing 11 is provided with the thickened region 11c. The wall thickness of the other regions of the outer casing 11, excluding the thickened region 11c, is T, and the wall thickness of the first sub-region 11d is T2. Alternatively, 0.5mm≤T2≤1.5mm.

[0149] The wall thickness of the first sub-region 11d in this embodiment is the same as that of the embodiment where the thickened region 11c is a region with equal wall thickness, that is, the same as T1. Therefore, it has the same beneficial effect, which will not be repeated here.

[0150] In some embodiments, referring to Figure 9, the wall thickness of the second sub-region 11e is T3, where T < T3 < 2T. That is, the wall thickness of the second sub-region 11e is greater than the wall thickness of the other regions of the outer shell 11 excluding the thickened region 11c, less than twice the wall thickness of the other regions of the outer shell 11 excluding the thickened region 11c, and less than the wall thickness of the first sub-region 11d.

[0151] For example, 1.1T, 1.2T, 1.3T, 1.4T, 1.5T, 1.6T, 1.7T, 1.8T, or 1.9T, etc.

[0152] In this embodiment, by setting the wall thickness of the second sub-region 11e to T < T3 < 2T and less than the wall thickness of the first sub-region 11d, the structural strength of the outer shell 11 is specifically enhanced. This ensures that the outer shell 11 has sufficient strength while reducing its weight and volume, reducing the amount of material used in the outer shell 11, lowering costs, and increasing the energy density of the battery 100.

[0153] In some embodiments, please continue to refer to Figure 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 the other regions of the outer shell 11 excluding the thickened region 11c, less than 1.5 times the wall thickness of the other regions of the outer shell 11 excluding 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.

[0154] For example, 1.1T, 1.15T, 1.2T, 1.25T, 1.3T, 1.35T, 1.4T, 1.45T, or 1.5T, etc.

[0155] In this embodiment, by setting the wall thickness of the third sub-region 11f to T < T4 < 1.5T and less than the wall thickness of the second sub-region 11e, the structural strength of the outer shell 11 is specifically enhanced. This ensures that the outer shell 11 has sufficient strength while reducing its weight and volume, reducing the amount of material used in the outer shell 11, lowering costs, and increasing the energy density of the battery 100.

[0156] In some embodiments, referring to Figures 6 to 8, the outer casing 11 further includes transition regions 11n disposed at both ends of the thickened region 11c. The wall thickness of the transition region 11n gradually increases or decreases along the extension direction of the thickened region 11c. The length dimension of the large surface of the outer casing 11 is L. The wall thickness of the thickened region 11c is the same along the extension direction of the thickened region 11c, and the length dimension of the thickened region 11c is L1. The length dimension of the inner sidewall of the transition region 11n is L4, where L4 < L - L1.

[0157] The inner wall of the transition region 11n is the side wall of the transition region 11n that is away from the outer wall of the outer shell 11.

[0158] In this embodiment, by providing transition regions 11n at both ends of the thickened region 11c, the thickened region 11c is smoothly connected to other regions of the outer shell 11, which not only improves the structural strength of the outer shell 11 but also provides scratch protection. Furthermore, by setting the length of the inner wall of the transition region 11n to L4 < L - L1, the slope and length of the transition region 11n can be set.

[0159] In some embodiments, referring to Figures 6 to 8, the included angle between the inner wall of the transition region 11n and the inner wall of the thickened region 11c is A, where 90° < A < 180°. For example, it can be 91°, 95°, 100°, 110°, 120°, 130°, 140°, 150°, 160°, 170°, or 179°, etc.

[0160] In this embodiment, the slope and length of the transition region 11n are set by setting the included angle between the inner wall of the transition region 11n and the inner wall of the thickened region 11c to 90° < A < 180°.

[0161] In some embodiments, as shown in Figures 4 and 5, the top cover 12 has the same shape as the inner shape of the outer shell 11, and the gap between the top cover 12 and the outer shell 11 is t, where 0.05mm ≤ t ≤ 0.3mm. For example, it can be 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, or 0.3mm, etc.

[0162] In this embodiment, by setting the gap between the top cover 12 and the outer shell 11 to 0.05mm-0.3mm, it is beneficial to improve the assembly and welding performance of the top cover 12 and the outer shell 11.

[0163] In some embodiments, the top cover 12 and / or the outer casing 11 are made of aluminum.

[0164] It is understood that when the top cover 12 and / or the outer casing 11 are made of aluminum, a thickened region 11c is formed by thickening the inner wall of at least a portion of the outer casing 11 at the opening 11b, and a connection region adapted to the thickened region 11c is formed on the edge of the top cover 12. The connection region is connected to the thickened region 11c, thereby improving the structural strength at the connection between the outer casing 11 and the top cover 12, thereby improving the connection strength between the outer casing 11 and the top cover 12, reducing the risk of fatigue cracking of the connection structure between the outer casing 11 and the top cover 12, improving the failure problem of the connection structure between the outer casing 11 and the top cover 12, improving the expansion resistance of the casing, and increasing the service life of the battery cell 10.

[0165] It should be noted that the length L of the large surface of the outer shell 11, the length L1 of the thickened region 11c, the length L2 of the first sub-region 11d, the length L3 of the second sub-region 11e, the length L4 of the inner wall of the transition region 11n, the length L5 of the third sub-region 11f, the wall thickness T of the other regions of the outer shell 11 excluding the thickened region 11c, the wall thickness T1 of the thickened region 11c, the wall thickness T2 of the first sub-region 11d, the wall thickness T3 of the second sub-region 11e, the wall thickness T4 of the third sub-region 11f, the included angle A between the inner wall of the transition region 11n and the inner wall of the thickened region 11c, and the gap t between the top cover 12 and the outer shell 11 can be obtained by testing and calculation using instruments such as a high-precision thickness gauge, an angle measuring instrument, and a vernier caliper under normal temperature conditions and when the top cover 12 is not assembled.

[0166] The battery cell 10 of this application will be further explained below with reference to specific test examples.

[0167] The test sample of this application embodiment: the inner wall of at least a portion of the outer shell 11 at the opening 11b is thickened to form a thickened region 11c, and the edge of the top cover 12 is formed with a connection region adapted to the thickened region 11c, and the connection region is connected to the thickened region 11c.

[0168] By conducting charge-discharge cycle experiments on the test samples and control groups of this application embodiment, and recording the number of cycles, the number of cycles for the five control groups of this application embodiment were 2015, 2336, 2165, 2380, and 2217, respectively, with an average of 2222 cycles. The number of cycles for the five test samples of the control groups were 2869, 2695, 2711, 2742, and 2796, respectively, with an average of 2762 cycles for the five test samples of this application embodiment. Compared with the control groups, the average number of cycles for the test samples of this application embodiment is significantly higher. The average value of the control group increased by 24.3%. When the electrode assembly expands cyclically and gas is generated during charging and discharging, forces are generated at the connection between the outer casing 11 and the top cover 12. The number of cycles of the battery cell 10 provided in this application embodiment is much greater than that of the control group. In other words, the battery cell 10 provided in this application embodiment improves the structural strength of the outer casing 11, reduces the risk of cracking of the connection structure between the outer casing 11 and the top cover 12, improves the problem of failure of the connection structure between the outer casing 11 and the top cover 12, improves fatigue performance, reduces the overall weld heat-affected deformation strain, and improves the service life of the battery cell 10.

[0169] In the description of this application, the references to terms such as "in one embodiment," "in some embodiments," "in other embodiments," "in yet another embodiment," or "exemplary," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the embodiments of this application. In this application, the illustrative expressions of the above terms do 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. Furthermore, without contradiction, those skilled in the art can combine the different embodiments or examples described in this application, as well as the features of the different embodiments or examples.

[0170] The above description is merely a preferred embodiment of this application and is not intended to limit the application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A single battery cell, comprising: The outer casing has a storage space and openings; A top cover and a sealing cover are provided at the opening; Electrode assembly, disposed within the receiving space; The inner wall of at least a portion of the outer shell at the opening is thickened to form a thickened region, and the edge of the top cover has a connecting region adapted to the thickened region, the connecting region being connected to the thickened region.

2. The battery cell according to claim 1, wherein the thickened region extends along the edge of the opening.

3. The battery cell according to claim 1, wherein 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.

4. The battery cell according to claim 1, wherein the thickened region comprises multiple sub-regions arranged sequentially along the extension direction of the thickened region, each sub-region having the same wall thickness, and any two adjacent sub-regions having different wall thicknesses.

5. The battery cell according to claim 1, wherein the battery cell is rectangular parallelepiped, and at least one large surface of the outer casing is provided with the thickened area; or, The battery cell is cylindrical, and at least a portion of the outer casing has the thickened area.

6. The battery cell according to claim 5, wherein the length dimension of the larger surface of the outer casing is L, and the length dimension of the thickened region is L1, wherein, 7. The battery cell according to claim 1, wherein the wall thickness of the outer casing, excluding the thickened region, is T, the wall thickness of the thickened region is the same along the extending direction of the thickened region, and the wall thickness of the thickened region is T1, wherein...

8. The battery cell according to claim 4, wherein the thickened region includes a first sub-region, two second sub-regions and two third sub-regions, the two second sub-regions are respectively connected to both sides of the first sub-region, the two third sub-regions are respectively connected to the two second sub-regions, and the wall thickness of the first sub-region, the second sub-regions and the third sub-regions decreases sequentially.

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

11. The battery cell according to claim 8, wherein the battery cell is rectangular, at least one large surface of the outer casing is provided with the thickened region, the wall thickness of the other regions of the outer casing excluding the thickened region is T, and the wall thickness of the first sub-region is T2, wherein... Alternatively, 0.5mm≤T2≤1.5mm.

12. The battery cell according to claim 11, wherein 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, where T < T4 < 1.5T.

13. The battery cell according to claim 5, wherein the outer casing further comprises transition regions disposed at both ends of the thickened region, the wall thickness of the transition regions gradually increasing or decreasing along the extension direction of the thickened region; The length dimension of the large surface of the outer shell is L, the wall thickness of the thickened region is the same along the extension direction of the thickened region, and the length dimension of the thickened region is L1. The length dimension of the inner sidewall of the transition region is L4. L4 < L - L1; and / or, The angle between the inner wall of the transition region and the inner wall of the thickened region is A. In the given information, 90 < A < 180.

14. The battery cell according to any one of claims 6-13, wherein the top cover and / or the outer casing is made of aluminum.

15. A battery comprising at least one battery cell as described in any one of claims 1-14.

16. An electrical device comprising the battery of claim 15, the battery being used to provide electrical energy to the electrical device.

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