Battery monomer, battery, electric equipment and energy storage device

Abstract

A battery cell (20), a battery (100), an electric device, and an energy storage device. The battery cell (20) comprises a housing (21). The shell (21) comprises a shell body (211) and an end cover (212), the shell body (211) is provided with an opening (211a), the shell body (211) comprises a first wall (24), the first wall (24) comprises a first opening part (241) and a first body part (242) which are sequentially arranged along a first direction (Z), the first direction (Z) is parallel to the thickness direction of the end cover (212), the first opening part (241) is close to the opening (211a) relative to the first body part (242), and the end cover (212) is welded with the first opening part (241) to seal the opening (211a). Wherein the first opening part (241) comprises a plurality of first thickening areas (241a) and at least one first transition area (241b), the plurality of first thickening areas (241a) are arranged in the circumferential direction of the opening (211a) at intervals, every two adjacent first thickening areas (241a) are connected through the corresponding first transition area (241b), and the maximum thickness of the first thickening areas (241a) is larger than the thickness of the first body part (242); the maximum thickness of the first thickened region (241a) is greater than the thickness of the first transition region (241b). The reliability of the battery cells (20) can be improved.

Description

Battery cells, batteries, electrical equipment and energy storage devices

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese patent application CN202420292359.X, filed on February 18, 2024, entitled “Battery cell, battery, electrical device and energy storage device”, the entire contents of which are incorporated herein by reference.

[0003] This application relates to the field of battery technology, and more specifically, to a battery cell, a battery, an electrical device, and an energy storage device.

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. For electric vehicles, battery technology is a crucial factor in their development.

[0005] Battery reliability is a crucial factor in battery manufacturing. Therefore, improving battery reliability is a pressing technical challenge in battery technology.

[0006] Summary of the Invention

[0007] This application provides a battery cell, a battery, an electrical device, and an energy storage device, which can improve the reliability of the battery cell.

[0008] This application is achieved through the following technical solution:

[0009] In a first aspect, embodiments of this application provide a battery cell including a casing. The casing includes a housing and an end cap. The housing has an opening and includes a first wall. The first wall includes a first opening and a first body portion sequentially disposed along a first direction, which is parallel to the thickness direction of the end cap. The first opening is closer to the opening than the first body portion. The end cap is welded to the first opening to close the opening. The first opening includes a plurality of first thickened regions and at least one first transition region. The plurality of first thickened regions are spaced apart circumferentially along the opening. Adjacent first thickened regions are connected by a first transition region. The maximum thickness of the first thickened region is greater than the thickness of the first body portion, and the maximum thickness of the first thickened region is greater than the thickness of the first transition region.

[0010] According to the battery cell of this application embodiment, a plurality of first thickened regions are arranged circumferentially around the opening. The maximum thickness of the first thickened region is greater than the thickness of the first body portion. The first thickened region is a thickened area of ​​the first opening, which can improve the strength of the first opening and the first wall, reduce the risk of cracking in the area near the welding position of the casing and the end cap, and improve the reliability of the battery cell. At the same time, the arrangement of multiple first thickened regions circumferentially around the opening can reduce the demolding difficulty of the casing during processing and manufacturing, and reduce the manufacturing difficulty of the battery cell.

[0011] According to some embodiments of this application, along the circumferential direction of the opening, the distance between any two adjacent first thickened areas is greater than or equal to 2 mm, and the distance between any two adjacent first thickened areas is less than or equal to 15 mm.

[0012] In the above scheme, the distance between two adjacent first thickened areas satisfies the above relationship. On the one hand, when the distance between any two adjacent first thickened areas is less than or equal to 15mm, the multiple first thickened areas have a large size in the circumferential direction of the opening, which can improve the strength of the first opening. On the other hand, when the distance between any two adjacent first thickened areas is greater than or equal to 2mm, it can reduce the demolding difficulty during shell processing and manufacturing, and facilitate demolding.

[0013] According to some embodiments of this application, along the second direction, the size of the first thickened area is greater than or equal to 0.1 times the size of the first wall, the size of the first thickened area is less than or equal to 0.5 times the size of the first wall, and the second direction, the first direction, and the thickness direction of the first wall are perpendicular to each other.

[0014] In the above scheme, the size of the first thickened area in the second direction satisfies the above relationship. On the one hand, when the size of the first thickened area is greater than or equal to 0.1 times the size of the first wall, the strength of the first opening can be improved. On the other hand, when the size of the first thickened area is less than or equal to 0.5 times the size of the first wall, the demolding difficulty during shell processing and manufacturing can be reduced.

[0015] According to some embodiments of this application, the thickness direction of the first thickened region is parallel to the thickness direction of the first wall, the difference between the maximum thickness of the first thickened region and the thickness of the first body is greater than or equal to 0.05 mm, and the difference between the maximum thickness of the first thickened region and the thickness of the first body is less than or equal to the thickness of the first body.

[0016] In the above scheme, the difference between the maximum thickness of the first thickened area and the thickness of the first body part satisfies the above relationship. On the one hand, when the difference between the maximum thickness of the first thickened area and the thickness of the first body part is greater than or equal to 0.05 mm, the first thickened area has high strength. On the other hand, when the difference between the maximum thickness of the first thickened area and the thickness of the first body part is less than or equal to the thickness of the first body part, the space occupied by the first thickened area is small, so that the battery cell can have high energy density.

[0017] According to some embodiments of this application, the maximum thickness of the first thickened area is greater than or equal to 0.25 mm, and the maximum thickness of the first thickened area is less than or equal to 2.4 mm.

[0018] In the above scheme, the thickness of the first thickened area satisfies the above relationship. On the one hand, when the maximum thickness of the first thickened area is greater than or equal to 0.25mm, the first thickened area has high strength. On the other hand, when the maximum thickness of the first thickened area is less than or equal to 2.4mm, the space occupied by the first thickened area is small.

[0019] According to some embodiments of this application, the thickness of the first body portion is greater than or equal to 0.2 mm, and the thickness of the first body portion is less than or equal to 1.2 mm.

[0020] In the above scheme, on the one hand, when the thickness of the first body part is greater than or equal to 0.2 mm, the first body part has high strength; on the other hand, when the thickness of the first body part is less than or equal to 1.2 mm, the space occupied by the first body part in the thickness direction of the first wall is small, so that the battery cell can have high energy density.

[0021] According to some embodiments of this application, the first body portion has a first surface facing the interior of the battery cell, and a first thickened region protrudes from the first surface.

[0022] In the above scheme, the first thickened area protrudes from the first surface, so that the side of the first thickened area away from the inside of the battery cell can be parallel to the side of the first body that is away from the inside of the battery cell, thereby reducing the space occupied by the first thickened area on the outside of the battery cell and reducing the risk of interference between the first thickened area and other components.

[0023] According to some embodiments of this application, an end cap is disposed in an opening, the end cap has a first side facing the first opening, the first side is provided with a first recessed area corresponding to the first thickened area, and at least a portion of the first thickened area is located in the first recessed area.

[0024] In the above scheme, at least a portion of the first thickened area is located within the first recessed area to facilitate the mating of the end cap with the first wall and to facilitate the connection between the end cap and the housing.

[0025] According to some embodiments of this application, the end cap has a second surface facing away from the interior of the battery cell, and along a first direction, the maximum distance between one end of the first thickened region facing away from the second surface and the second surface is less than or equal to 10 mm.

[0026] In the above scheme, along the first direction, the maximum distance between the end of the first thickened area away from the second surface and the second surface is less than or equal to 10mm. This not only makes the first opening have high strength to reduce the risk of the shell cracking near the welding position of the shell and the end cap, but also facilitates the demolding of the shell during the manufacturing process, making it easier to manufacture.

[0027] According to some embodiments of this application, a plurality of first thickened regions include a first central thickened region, which extends along a second direction and passes through the center of the first wall in the second direction. The second direction, the first direction, and the thickness direction of the first wall are perpendicular to each other.

[0028] In the above scheme, the first central thickened area passes through the center of the first wall in the second direction, which makes the strength of the area near the center of the first wall in the second direction higher, which helps to reduce the risk of cracking of the shell in the area near the welding position of the shell and the end cap.

[0029] According to some embodiments of this application, a plurality of first thickened regions are centrally symmetrically arranged about the first wall in a second direction, and the second direction, the first direction, and the thickness direction of the first wall are perpendicular to each other.

[0030] In the above scheme, the arrangement of multiple first thickened areas gives the first opening high strength and improves the welding strength between the first opening and the end cap.

[0031] According to some embodiments of this application, the housing further includes a second wall connected to the first wall, and an end cap connected to the second wall. The second wall includes a second opening and a second body portion spaced apart along a first direction. The second opening is close to the second body portion relative to the opening, and the end cap is welded to the second opening. The second opening includes a plurality of second thickened regions and at least one second transition region. The plurality of second thickened regions are spaced apart circumferentially along the opening, and two adjacent second thickened regions are connected through the second transition region. The maximum thickness of the second thickened region is greater than the thickness of the second body portion, and the maximum thickness of the second thickened region is greater than the thickness of the second transition region.

[0032] In the above scheme, the second wall is arranged adjacent to the first wall, and the structure of the second wall is similar to that of the first wall. The setting of the second thickened area can enhance the strength of the second opening and the second wall, further reducing the risk of cracking in the area near the welding position of the casing and the end cap. At the same time, multiple second thickened areas are arranged circumferentially along the opening, which can reduce the demolding difficulty of the casing during processing and manufacturing, and reduce the manufacturing difficulty of the battery cells.

[0033] According to some embodiments of this application, the area of ​​the outer surface of the second wall is smaller than the area of ​​the outer surface of the first wall.

[0034] In the above scheme, the area of ​​the outer surface of the second wall is smaller than the area of ​​the outer surface of the first wall. The first wall can be the large surface of the shell. The setting of the first thickened area and the setting of the second thickened area can reduce the risk of cracking of the shell in the area near the welding position of the shell and the end cap.

[0035] According to some embodiments of this application, the second body portion has a third surface facing the interior of the battery cell, and a second thickened region protrudes from the third surface.

[0036] In the above scheme, the second thickened area protrudes from the third surface, so that the side of the second thickened area away from the inside of the battery cell can be parallel to the side of the second body that is away from the inside of the battery cell, thereby reducing the space occupied by the second thickened area on the outside of the battery cell and reducing the risk of interference between the second thickened area and other components.

[0037] According to some embodiments of this application, an end cap is disposed within an opening, the end cap having a second side facing the second opening, the second side having a second recessed area corresponding to the second thickened area, and at least a portion of the second thickened area being located within the second recessed area.

[0038] In the above scheme, the setting of the second recessed area facilitates the fit between the end cap and the second wall, and facilitates the connection between the end cap and the shell.

[0039] According to some embodiments of this application, the thickness of the first transition region is equal to the thickness of the first body portion.

[0040] In the above scheme, the thickness of the first transition zone is equal to the thickness of the first body part, which facilitates processing and manufacturing.

[0041] According to some embodiments of this application, there are two first walls, which are disposed opposite each other in a third direction and are parallel to the thickness direction of the first walls; the housing also includes a bottom wall and two second walls disposed opposite each other in a second direction, the two first walls and the two second walls forming an opening, the bottom wall being disposed opposite each other in a first direction, and the first direction, the second direction and the third direction being perpendicular to each other.

[0042] In the above scheme, the bottom wall and the opening are arranged opposite each other. During the assembly of the battery cell, the bottom wall can support the electrode assembly to facilitate the positioning of the electrode assembly.

[0043] According to some embodiments of this application, the housing has a prismatic structure, has two openings, and has two end caps, which respectively close the two openings.

[0044] In the above scheme, the housing has two openings, and two end caps respectively close the two openings to facilitate the assembly of the electrode assembly with the housing.

[0045] Secondly, embodiments of this application also provide a battery, which includes a battery cell as provided in any of the above embodiments.

[0046] According to some embodiments of this application, there are multiple battery cells, which are stacked along a third direction to form a battery cell group. The third direction is parallel to the thickness direction of the first wall. The battery also includes an end plate, which is disposed at the end of the battery cell group along the third direction. In the direction from the first body portion to the first opening portion, at least a portion of the first opening portion extends beyond the end plate.

[0047] In the above scheme, the end plate is set at the end of the battery cell pack in the third direction. The end plate has a large connection area with the housing of the adjacent battery cell to form a constraint on the housing and reduce the risk of cracking in the area near the welding position of the housing and the end cover.

[0048] Thirdly, embodiments of this application also provide an electrical device, which includes a battery cell or battery as provided in any of the above embodiments, the battery cell or battery being used to provide electrical energy.

[0049] Fourthly, embodiments of this application also provide an energy storage device, which includes a battery cell or battery as provided in any of the above embodiments.

[0050] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application.

[0051] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0053] Figure 2 is an exploded view of a battery provided in some embodiments of this application;

[0054] Figure 3 is an exploded view of a battery cell provided in some embodiments of this application;

[0055] Figure 4 is an exploded structural diagram of the shell provided in some embodiments of this application;

[0056] Figure 5 is a top view of the housing provided in some embodiments of this application;

[0057] Figure 6 is a cross-sectional view along the AA direction of Figure 5;

[0058] Figure 7 is a magnified view of part B in Figure 6;

[0059] Figure 8 is a cross-sectional view along the CC direction of Figure 5;

[0060] Figure 9 is a magnified view of part D in Figure 8;

[0061] Figure 10 is a schematic diagram of the assembly of the end cap and the first opening provided in some embodiments of this application;

[0062] Figure 11 is a schematic diagram of the end cap structure provided in some embodiments of this application;

[0063] Figure 12 is a magnified view of part E in Figure 11;

[0064] Figure 13 is a schematic diagram of the structure of the housing provided in some other embodiments of this application;

[0065] Figure 14 is a schematic diagram of the assembly of the end cap and the second opening provided in some embodiments of this application;

[0066] Figure 15 is a structural schematic diagram of the end cap provided in some other embodiments of this application;

[0067] Figure 16 is a magnified view of part F in Figure 15;

[0068] Figure 17 is a schematic diagram of the assembly of an end plate and multiple battery cells provided in some embodiments of this application;

[0069] Figure 18 is a schematic diagram of the assembly of the end plate and the battery cell provided in some embodiments of this application;

[0070] Figure 19 is a magnified view of part G in Figure 18.

[0071] The accompanying drawings are not drawn to scale.

[0072] Marking Explanation: 100 - Battery; 10 - Housing; 11 - First Sub-Housing; 12 - Second Sub-Housing; 20 - Individual Battery Cell; 20a - Individual Battery Cell Assembly; 21 - Housing; 210 - First Welding Area; 211 - Housing; 211a - Opening; 212 - End Cap; 212a - First Side; 212b - First Recessed Area; 212c - Second Side; 212d - Second Recessed Area; 212e - Second Surface; 22 - Electrode Assembly; 23 - Electrode Terminal; 24 - First Wall; 241 - First Opening Part; 241a-First thickened area; 241b-First transition area; 241c-First central thickened area; 242-First body part; 242a-First surface; 25-Second wall; 251-Second opening; 251a-Second thickened area; 251b-Second transition area; 252-Second body part; 252a-Third surface; 26-Bottom wall; 30-End plate; 200-Controller; 300-Motor; 1000-Vehicle; X-Thickness direction of the first wall; Y-Second direction; Z-First direction.

[0073] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0074] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application 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, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0075] In this application, the reference to "embodiment" means that a specific 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 mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0076] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0077] 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, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0078] In this application, "multiple" refers to two or more (including two), and similarly, "multiple groups" refers to two or more (including two), and "multiple pieces" refers to two or more (including two).

[0079] In some embodiments, the battery can be a battery module, and when there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0080] In some embodiments, the battery can be a battery pack, which includes a housing and individual battery cells, with the individual battery cells or battery modules housed within the housing.

[0081] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0082] In some embodiments, the battery can be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0083] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0084] The battery cell may be, but is not limited to, lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc.

[0085] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0086] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0087] As an 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.

[0088] As an example, the positive electrode current collector can be a metal foil or a composite current collector. For example, 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. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0089] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used.

[0090] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0091] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, 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, or made of carbon, nickel, or titanium, etc.

[0092] In some embodiments, 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.

[0093] As an example, the negative electrode active material may be a 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.

[0094] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0095] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a separate component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes.

[0096] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0097] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0098] In some implementations, the electrode assembly is a stacked structure.

[0099] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be a steel housing, an aluminum housing, or a composite metal housing (such as a copper-aluminum composite housing).

[0100] In some embodiments, the housing includes an end cap and a casing, the casing having an opening, and the end cap closing the opening to form a sealed space for accommodating substances such as electrode assemblies and electrolytes. The casing may have one or more openings. The end cap may also be provided one or more times.

[0101] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal 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 end cap or on the housing.

[0102] In some implementations, an explosion-proof valve is provided on the housing. The explosion-proof valve is used to release the internal pressure of the battery cells.

[0103] As an example, the battery cell can be 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.

[0104] 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.

[0105] In some embodiments, a battery cell includes a casing and an electrode assembly disposed within the casing. The casing includes a housing and end caps, the housing having an opening and the end caps closing the opening. The end caps are typically welded to the housing. The high temperatures during welding can easily cause a heat-affected zone (HAZ) to form between the end cap and the housing near the weld position, resulting in lower strength in the portion of the end cap and housing within the HAZ. During the charging and discharging process of the battery cell, or when the electrode assembly generates excessive gas, or when the battery cell experiences thermal runaway, cracks can easily occur in the area near the weld position between the housing and the end cap, leading to casing damage and reducing the battery cell's lifespan and reliability.

[0106] In view of this, the present application provides a technical solution in which a battery cell includes a casing, the casing includes a housing and an end cap, the housing includes a first wall, the first wall includes an opening and a first body portion arranged sequentially along a first direction, the first direction being parallel to the thickness direction of the end cap, the first opening being closer to the opening relative to the first body portion, and the end cap being welded to the first opening to close the opening. The first opening includes multiple first thickened areas and at least one first transition area, the multiple first thickened areas and at least one first transition area being staggered along the circumference of the opening, the maximum thickness of the first thickened area being greater than the thickness of the first body portion, and the maximum thickness of the first thickened area being greater than the thickness of the first transition area, which can improve the strength of the first opening and reduce the risk of cracking of the casing in the area near the welding position of the housing and the end cap, thus making the battery cell have higher reliability.

[0107] In this type of battery cell, the maximum thickness of the first thickened region is greater than the thickness of the first body portion. This thickening process gives the first thickened region higher strength, enhancing the strength of the first opening. The connection between the end cap and the first opening reduces the risk of cracking in the area near the weld between the casing and the end cap, thus improving the reliability of the battery cell. Furthermore, the multiple first thickened regions spaced circumferentially along the opening reduce the difficulty of demolding the casing during manufacturing, thereby reducing the manufacturing difficulty of the battery cell.

[0108] The batteries disclosed in this application can be used, but are not limited to, in electrical equipment such as vehicles, ships, or aircraft. A power system for such electrical equipment can be constructed using batteries disclosed in this application.

[0109] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric bicycles, electric motorcycles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0110] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0111] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is installed inside the vehicle 1000, and the battery 100 can 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, the battery 100 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 of the vehicle 1000.

[0112] The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300, for example, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0113] In some embodiments 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 for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0114] Please refer to Figure 2, which is an exploded view of a battery provided in some embodiments of this application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can adopt various structures. In some embodiments, the housing 10 may include a first sub-housing 11 and a second sub-housing 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second sub-housing 12 may be a hollow structure with one open end, while the first sub-housing 11 may be a plate-like structure, covering the open side of the second sub-housing 12 so that the first sub-housing 11 and the second sub-housing 12 jointly define the space. Alternatively, both the first sub-housing 11 and the second sub-housing 12 may be hollow structures with one open side, with the open side of the first sub-housing 11 covering the open side of the second sub-housing 12.

[0115] In battery 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0116] Among them, the battery cell 20 can be a secondary battery or a primary battery; the battery cell 20 can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited to these.

[0117] Please refer to Figure 3, which is an exploded view of a battery cell provided in some embodiments of this application. As shown in Figure 3, the battery cell 20 includes a housing 21, an electrode assembly 22, and other functional components. The housing 21 includes a shell 211 and an end cap 212. The shell 211 has an opening, and the end cap 212 closes the opening to isolate the internal environment of the battery cell 20 from the external environment.

[0118] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20, wherein the formed internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. The housing 211 can have various shapes and sizes. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The housing 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0119] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with certain hardness and strength (such as aluminum alloy), so that end cap 212 is not easily deformed under pressure and impact, allowing battery cell 20 to have higher structural strength and improved reliability. Functional components such as electrode terminals 23 can be provided on end cap 212. Electrode terminals 23 can be used for electrical connection with electrode assembly 22 to output or input electrical energy to battery cell 20. The material of end cap 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not impose special limitations on this. In some embodiments, an insulating structure can also be provided on the inner side of end cap 212. The insulating structure can be used to isolate the electrical connection components inside housing 211 from end cap 212 to reduce the risk of short circuit. For example, the insulating structure can be made of plastic, rubber, etc.

[0120] Electrode assembly 22 is the component in the battery cell 20 where the electrochemical reaction occurs. The housing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets to separate them and prevent internal short circuits. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly, while the portions without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body.

[0121] Please refer to Figure 3, and further refer to Figures 4 to 9. Figure 4 is an exploded structural diagram of the casing provided in some embodiments of this application. Figure 5 is a top view of the casing provided in some embodiments of this application. Figure 6 is a cross-sectional view along the AA direction of Figure 5. Figure 7 is a partial enlarged view at point B in Figure 6. Figure 8 is a cross-sectional view along the CC direction of Figure 5. Figure 9 is a partial enlarged view at point D in Figure 8. According to some embodiments of this application, this application provides a battery cell 20, which includes a casing 21. The casing 21 includes a housing 211 and an end cap 212. The housing 211 has an opening 211a. The housing 211 includes a first wall 24, which includes a first opening 241 and a first body portion 242 sequentially arranged along a first direction Z. The first direction Z is parallel to the thickness direction of the end cap 212. The first opening 241 is close to the opening 211a relative to the first body portion 242. The end cap 212 is welded to the first opening 241 to close the opening 211a. The first opening 241 includes a plurality of first thickened regions 241a and at least one first transition region 241b. The plurality of first thickened regions 241a are arranged at circumferential intervals along the opening 211a. Two adjacent first thickened regions 241a are connected by the first transition region 241b. The maximum thickness of the first thickened region 241a is greater than the thickness of the first body portion 242, and the maximum thickness of the first thickened region 241a is greater than the thickness of the first transition region 241b.

[0122] In the diagram, the direction indicated by the letter Z is the first direction, which is parallel to the thickness direction of the end cap 212. The first direction Z can also be parallel to the height direction of the battery cell 20. The direction indicated by the letter X can be the thickness direction of the first wall 24. The thickness directions of the first thickened region 241a and the first transition region 241b are both parallel to the thickness direction X of the first wall. The thickness direction X of the first wall is perpendicular to the first direction Z. The thickness direction X of the first wall can be parallel to the width direction of the battery cell 20, or it can be parallel to the length direction of the battery cell 20.

[0123] To facilitate the distinction between the first opening 241 and the first body 242, the dashed line F1 in Figures 7 and 9 is the dividing line between the first opening 241 and the first body 242.

[0124] In some embodiments, the battery cell 20 further includes an electrode assembly 22 located within the housing 211.

[0125] Along the first direction Z, the first body portion 242 is farther away from the opening 211a than the first opening portion 241. The first opening portion 241 can form the opening 211a so that the opening 211a can be closed after the end cap 212 is welded to the first opening portion 241.

[0126] Please refer to Figure 10, which is a schematic diagram of the assembly of the end cap and the first opening provided in some embodiments of this application. In some embodiments, the end cap 212 is welded to a portion of the first opening 241 to form a first weld area 210, which may be referred to as a solder mark.

[0127] In some embodiments, the first body portion 242 may be a uniform thickness structure, and the thickness of the first body portion 242 at any position may be the maximum thickness of the first body portion 242.

[0128] In some embodiments, the first thickened region 241a can be a constant thickness structure or a variable thickness structure. When the first thickened region 241a is a constant thickness structure, the maximum thickness of the first thickened region 241a is the thickness at any position of the first thickened region 241a; when the first thickened region 241a is a variable thickness structure, the maximum thickness of the first thickened region 241a is the thickness at the position where the thickness of the first thickened region 241a is the maximum.

[0129] Optionally, when the first thickened region 241a is a variable thickness structure, the thickness of the first thickened region 241a can gradually decrease from the end away from the first body portion 242 toward the end closer to the first body portion 242, and the area with the largest thickness of the first thickened region 241a is located at the end away from the first body portion 242.

[0130] In some embodiments, the first transition region 241b can be a constant thickness structure or a variable thickness structure. Optionally, the first transition region 241b is a constant thickness structure, and the thickness of the first transition region 241b is the thickness at any position of the first transition region 241b.

[0131] Multiple first thickened regions 241a are spaced apart circumferentially around the opening 211a, such that the multiple first thickened regions 241a and at least one first transition region 241b can be staggered along the circumferential direction of the opening 211a. The number of first thickened regions 241a can be greater than the number of first transition regions 241b, or the number of first thickened regions 241a can be equal to the number of first transition regions 241b. For example, when there are three first thickened regions 241a and two first transition regions 241b, the first thickened regions 241a, first transition regions 241b, first thickened regions 241a, first transition regions 241b, and first thickened regions 241a are distributed sequentially along the circumferential direction of the opening 211a.

[0132] According to the battery cell 20 of this application embodiment, a plurality of first thickened regions 241a are arranged circumferentially around the opening 211a. The maximum thickness of the first thickened region 241a is greater than the thickness of the first body portion 242. The first thickened region 241a is a thickened area of ​​the first opening 241, which can improve the strength of the first opening 241, improve the strength of the first wall 24, reduce the risk of cracking of the housing 211 in the area near the welding position of the housing 211 and the end cap 212, and improve the reliability of the battery cell 20. At the same time, the arrangement of a plurality of first thickened regions 241a circumferentially around the opening 211a can reduce the demolding difficulty of the housing 211 during processing and manufacturing, and reduce the manufacturing difficulty of the battery cell 20.

[0133] In some embodiments, the dimensions of the plurality of first thickened regions 241a may be equal or unequal. The dimensions of the first thickened regions 241a may include the thickness, length, and width of the first thickened regions 241a.

[0134] In some embodiments, the dimensions of the plurality of first transition regions 241b may be equal or unequal. The dimensions of the first transition regions 241b may include the thickness, length, and width of the first transition regions 241b.

[0135] Please refer to Figure 5. According to some embodiments of this application, along the circumferential direction of the opening 211a, the distance between any two adjacent first thickened areas 241a is greater than or equal to 2 mm, and the distance between any two adjacent first thickened areas 241a is less than or equal to 15 mm.

[0136] The distance between any two adjacent first thickened areas 241a is L1, that is, 2mm≤L1≤15mm.

[0137] Optionally, L1 can be, but is not limited to, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc.

[0138] In the above scheme, the distance between two adjacent first thickened areas 241a satisfies the above relationship. On the one hand, when L1≤15mm, multiple first thickened areas 241a can occupy a larger size in the circumferential direction of the opening 211a, which can improve the strength of the first opening 241. On the other hand, when L1≥2mm, it can reduce the demolding difficulty during the processing and manufacturing of the shell 211 and facilitate demolding.

[0139] According to some embodiments of this application, 5mm≤L1≤10mm.

[0140] Optionally, L1 can be, but is not limited to, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.5mm, 9mm, 9.5mm, 10mm, etc.

[0141] In the above scheme, compared with L1 < 5mm, when L1 ≥ 5mm, the demolding difficulty during the processing and manufacturing of the shell 211 is further reduced; compared with L1 > 10mm, when L1 ≤ 10mm, the first opening 241 has higher strength, reducing the risk of cracking of the shell 211 in the area near the welding position of the shell 211 and the end cap 212.

[0142] Please refer to Figure 5. According to some embodiments of this application, along the second direction Y, the size of the first thickened area 241a is greater than or equal to 0.1 times the size of the first wall 24, and the size of the first thickened area 241a is less than or equal to 0.5 times the size of the first wall 24. The second direction Y, the first direction Z, and the thickness direction X of the first wall are perpendicular to each other.

[0143] Along the second direction Y, the dimension of the first wall 24 is L2, and the dimension of the first thickened area 241a is L3, satisfying 0.1*L2≤L3<0.5*L2.

[0144] In the diagram, the direction indicated by the letter Y can be a second direction, which can be parallel to the length direction of the battery cell 20 or parallel to the width direction of the battery cell 20. The second direction Y is part of the circumferential direction of the opening 211a.

[0145] 0.1*L2 refers to 0.1 times the dimension of the first wall 24 in the second direction Y. 0.5*L2 refers to 0.5 times the dimension of the first wall 24 in the second direction Y.

[0146] Optionally, L3 can be, but is not limited to, 0.1*L2, 0.15*L2, 0.2*L2, 0.25*L2, 0.3*L2, 0.35*L2, 0.4*L2, 0.45*L2, etc.

[0147] In the above scheme, the dimensions of the first thickened area 241a in the second direction Y satisfy the above relationship, which can improve the strength of the first opening 241 on the one hand, and reduce the demolding difficulty during the processing and manufacturing of the shell 211 on the other hand.

[0148] In some embodiments, the dimensions of the plurality of first thickened regions 241a in the second direction Y may be equal or unequal. When the dimensions of the plurality of first thickened regions 241a in the second direction Y are equal, it facilitates processing and manufacturing. When the dimensions of the first thickened regions 241a in the second direction Y are unequal, it can meet the requirements for local thickening and reduce the difficulty of demolding the shell.

[0149] According to some embodiments of this application, 0.2*L2≤L3≤0.25*L2.

[0150] Optionally, L3 can be, but is not limited to, 0.2*L2, 0.21*L2, 0.22*L2, 0.23*L2, 0.24*L2, 0.25*L2, etc.

[0151] In the above scheme, compared with L3 < 0.2*L2, when L3 ≥ 0.2*L2, the first thickened area 241a has a larger length in the second direction Y, which further enhances the strength of the first opening 241; compared with L3 > 0.25*L2, when L3 ≤ 0.25*L2, the demolding difficulty during the processing and manufacturing of the shell 211 is further reduced.

[0152] Referring to Figures 7 and 9, according to some embodiments of this application, the thickness direction of the first thickened region 241a is parallel to the thickness direction X of the first wall, the difference between the maximum thickness of the first thickened region 241a and the thickness of the first body portion 242 is greater than or equal to 0.05 mm, and the difference between the maximum thickness of the first thickened region 241a and the thickness of the first body portion 242 is less than or equal to the thickness of the first body portion 242.

[0153] The thickness of the first body part 242 is t1, and the maximum thickness of the first thickened region 241a is t2, satisfying that 0.05mm≤t2-t1≤t1.

[0154] In some embodiments, referring to Figure 9, the thickness of the first transition region 241b can be t3.

[0155] t2-t1 refers to the difference between the maximum thickness of the first thickened region 241a and the thickness of the first body portion 242, which can be understood as the thickness value of the first thickened region 241a relative to the first body portion 242. Wherein, t1 > 0.05 mm.

[0156] In the above scheme, the maximum thickness of the first thickened region 241a and the thickness difference of the first body part 242 satisfy the above relationship. On the one hand, the first thickened region 241a has high strength, and on the other hand, the first thickened region 241a occupies a small space, so that the battery cell 20 can have a high energy density.

[0157] According to some embodiments of this application, 0.2mm≤t2-t1≤0.8*t1.

[0158] In the above scheme, compared with t2-t1<0.2mm, when t2-t1≥0.2mm, the strength of the first thickened region 241a is further enhanced, so that the first opening 241 has higher strength; compared with t2-t1>0.8*t1, when t2-t1≤0.8*t1, the space occupied by the first thickened region 241a is further reduced, and the impact on the energy density of the battery cell 20 is reduced.

[0159] According to some embodiments of this application, the maximum thickness of the first thickened region 241a is greater than or equal to 0.25 mm, and the maximum thickness of the first thickened region 241a is less than or equal to 2.4 mm.

[0160] Optionally, t2 can be, but is not limited to, 0.25mm, 0.3mm, 0.35mm, 0.4mm, 0.45mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, etc.

[0161] In the above scheme, the thickness of the first thickened region 241a satisfies the above relationship, which on the one hand makes the first thickened region 241a have high strength, and on the other hand makes the space occupied by the first thickened region 241a small.

[0162] According to some embodiments of this application, 0.8mm ≤ t2 ≤ 1.8mm.

[0163] Optionally, t2 can be, but is not limited to, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, 1.05mm, 1.1mm, 1.15mm, 1.2mm, 1.25mm, 1.3mm, 1.35mm, 1.4mm, 1.45mm, 1.5mm, 1.55mm, 1.6mm, 1.65mm, 1.7mm, 1.75mm, 1.8mm, etc.

[0164] In the above scheme, compared with t2 < 0.8 mm, when t2 ≥ 0.8 mm, the first thickened region 241a has higher strength, and the first opening 241 has higher strength; compared with t2 > 1.8 mm, when t2 ≤ 1.8 mm, the space occupied by the first thickened region 241a is smaller, reducing the impact on the energy density of the battery cell 20.

[0165] According to some embodiments of this application, the thickness of the first body portion 242 is greater than or equal to 0.2 mm, and the thickness of the first body portion 242 is less than or equal to 1.2 mm.

[0166] Optionally, t1 can be, but is not limited to, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, etc.

[0167] In the above scheme, the thickness of the first body part 242 satisfies the above relationship. On the one hand, when the thickness of the first body part 242 is greater than or equal to 0.2 mm, the first body part 242 has high strength. On the other hand, when the thickness of the first body part 242 is less than or equal to 1.2 mm, the space occupied by the first body part 242 in the thickness direction X of the first wall is small, so that the battery cell 20 has high energy density.

[0168] According to some embodiments of this application, 0.6mm ≤ t1 ≤ 1mm.

[0169] Optionally, t1 can be, but is not limited to, 0.6mm, 0.65mm, 0.7mm, 0.75mm, 0.8mm, 0.85mm, 0.9mm, 0.95mm, 1mm, etc.

[0170] In the above scheme, compared with t1 < 0.6 mm, when t1 ≥ 0.6 mm, the first body part 242 has higher strength; compared with t1 > 1 mm, when t1 ≤ 1 mm, the first body occupies less space, and the battery cell 20 has higher energy density.

[0171] Referring to Figures 7 and 10, according to some embodiments of this application, the first body portion 242 has a first surface 242a facing the interior of the battery cell 20, and a first thickened region 241a protrudes from the first surface 242a.

[0172] In the above scheme, the first thickened area 241a protrudes from the first surface 242a, so that the side of the first thickened area 241a away from the inside of the battery cell 20 can be parallel to the side of the first body part 242 away from the inside of the battery cell 20, thereby reducing the space occupied by the first thickened area 241a on the outside of the battery cell 20 and reducing the risk of interference between the first thickened area 241a and other components.

[0173] Please refer to Figure 4, and further refer to Figures 11 and 12. Figure 11 is a structural schematic diagram of the end cap provided in some embodiments of this application, and Figure 12 is a partial enlarged view of point E in Figure 11. According to some embodiments of this application, the end cap 212 is disposed in the opening 211a. The end cap 212 has a first side surface 212a facing the first opening 241. The first side surface 212a is provided with a first recessed area 212b corresponding to the first thickened area 241a. At least a portion of the first thickened area 241a is located in the first recessed area 212b.

[0174] The end cap 212 is disposed in the opening 211a, and the side of the end cap 212 is connected to the inner surface of the housing 211 to facilitate welding of the end cap 212 to the housing 211.

[0175] The first recessed area 212b refers to the area of ​​the end cap 212 corresponding to the first thickened area 241a. The first recessed area 212b is a recess formed on the first side surface 212a. In the thickness direction X of the first wall, the first recessed area 212b is recessed relative to other areas in a direction away from the first wall 24, so that at least a portion of the first thickened area 241a is located in the first recessed area 212b.

[0176] In the above scheme, at least a portion of the first thickened area 241a is located in the first recessed area 212b, so as to facilitate the fit between the end cap 212 and the first wall 24, and to facilitate the welding of the end cap 212 and the housing 211.

[0177] Referring to Figure 10, according to some embodiments of this application, the end cap 212 has a second surface 212e facing away from the interior of the battery cell 20. Along the first direction Z, the maximum distance between the end of the first thickened region 241a facing away from the second surface 212e and the second surface 212e is less than or equal to 10 mm.

[0178] The maximum distance between the end of the first thickened region 241a that is away from the second surface 212e and the second surface 212e is h1, which satisfies h1≤10mm.

[0179] The maximum distance between the end of the first thickened region 241a away from the second surface 212e and the second surface 212e refers to the maximum distance between the end of the first thickened region 241a near the first body portion 242 and the second surface 212e along the first direction Z.

[0180] In the above scheme, along the first direction Z, the maximum distance between the end of the first thickened area 241a facing away from the second surface 212e and the second surface 212e is less than or equal to 10mm. This not only makes the first opening 241 have high strength to reduce the risk of the shell 211 cracking near the welding position of the shell 211 and the end cap 212, but also makes it easy for the shell 211 to be demolded during the processing and manufacturing process, which is convenient for processing and manufacturing.

[0181] Please refer to Figure 4 and further to Figure 13, which is a schematic diagram of the structure of the housing provided in some other embodiments of this application. According to some embodiments of this application, a plurality of first thickened regions 241a include a first central thickened region 241c, which extends along the second direction Y and passes through the center of the first wall 24 in the second direction Y. The second direction Y, the first direction Z, and the thickness direction X of the first wall are perpendicular to each other.

[0182] The center of the first central thickened region 241c in the second direction Y may coincide with the center of the first wall 24 in the second direction Y, or the center of the first central thickened region 241c in the second direction Y may not coincide with the center of the first wall 24 in the second direction Y.

[0183] Among the multiple first thickened regions 241a, some of the first thickened regions 241a can be distributed at both ends of the first middle thickened region 241c in the second direction Y, so that the first wall 24 is thickened at multiple positions in the second direction Y, thereby improving the strength of the first opening 241.

[0184] In the above scheme, the first central thickened area 241c passes through the center of the first wall 24 in the second direction Y, so that the strength of the area near the center of the first wall 24 in the second direction Y is high, which helps to reduce the risk of cracking of the shell 211 in the area near the welding position of the shell 211 and the end cover 212.

[0185] According to some embodiments of this application, a plurality of first thickened regions 241a are centrally symmetrically arranged about the first wall 24 in the second direction Y, and the second direction Y, the first direction Z and the thickness direction X of the first wall are perpendicular to each other.

[0186] In some embodiments, one of the plurality of first thickened regions 241a may pass through the center of the first wall 24 in the second direction Y. For example, the plurality of first thickened regions 241a may include a first central thickened region 241c, which may pass through the center of the first wall 24 in the second direction Y.

[0187] In some embodiments, at least one of the first transition zones 241b may pass through the center of the first wall 24 in the second direction Y.

[0188] In the above scheme, the arrangement of multiple first thickened areas 241a makes the first opening 241 have high strength and improves the welding strength between the first opening 241 and the end cap 212.

[0189] Please refer to Figure 3, and further refer to Figure 13. According to some embodiments of this application, the housing 211 further includes a second wall 25 connected to the first wall 24. An end cap 212 is connected to the second wall 25. The second wall 25 includes a second opening 251 and a second body portion 252 spaced apart along a first direction Z. The second opening 251 is closer to the opening 211a than the second body portion 252. The end cap 212 is welded to the second opening 251. The second opening 251 includes a plurality of second thickened regions 251a and at least one second transition region 251b. The plurality of second thickened regions 251a are spaced apart circumferentially along the opening 211a. Adjacent second thickened regions 251a are connected through the second transition region 251b. The maximum thickness of the second thickened region 251a is greater than the thickness of the second body portion 252, and the maximum thickness of the second thickened region 251a is greater than the thickness of the second transition region 251b.

[0190] The thickness direction of the second wall 25 can be parallel to the second direction Y.

[0191] The second wall 25 is arranged adjacent to the first wall 24. There can be two second walls 25 and two first walls 24. The two second walls 25 are spaced apart along the second direction Y, and the two first walls 24 are spaced apart along the thickness direction X of the first wall. The two ends of the second wall 25 are respectively connected to the two first walls 24.

[0192] Along the first direction Z, the second body portion 252 is farther away from the opening 211a than the second opening portion 251. The second opening portion 251 can form the opening 211a so that the opening 211a can be closed after the end cap 212 is connected to the second opening portion 251.

[0193] In some embodiments, the end cap 212 is welded to a portion of the second opening 251 to form a second weld zone, which may be referred to as a weld mark.

[0194] In some embodiments, the second body portion 252 may be a uniform thickness structure, and the thickness of the second body portion 252 at any position may be the maximum thickness of the second body portion 252.

[0195] In some embodiments, the second thickened region 251a can be a constant thickness structure or a variable thickness structure. When the second thickened region 251a is a constant thickness structure, the maximum thickness of the second thickened region 251a is the thickness at any position of the second thickened region 251a; when the second thickened region 251a is a variable thickness structure, the maximum thickness of the second thickened region 251a is the thickness at the position where the thickness of the second thickened region 251a is the maximum.

[0196] Optionally, when the second thickened region 251a is a variable thickness structure, the thickness of the second thickened region 251a can gradually decrease from the end away from the second body portion 252 toward the end closer to the second body portion 252, and the area with the largest thickness of the second thickened region 251a is located at the end away from the second body portion 252.

[0197] In some embodiments, the second transition region 251b can be a constant thickness structure or a variable thickness structure. Optionally, the second transition region 251b is a constant thickness structure, and the thickness of the second transition region 251b is the thickness at any position of the second transition region 251b.

[0198] Multiple second thickened regions 251a are spaced apart circumferentially around the opening 211a, such that the multiple second thickened regions 251a and at least one second transition region 251b can be staggered along the circumference of the opening 211a. The number of second thickened regions 251a can be greater than the number of second transition regions 251b, or the number of second thickened regions 251a can be equal to the number of second transition regions 251b. For example, when there are two second thickened regions 251a and one second transition region 251b, the second thickened regions 251a, second transition regions 251b, and second thickened regions 251a are distributed sequentially along the circumference of the opening 211a.

[0199] In the above scheme, the second wall 25 is arranged adjacent to the first wall 24, and the structure of the second wall 25 is similar to that of the first wall 24. The provision of the second thickened area 251a can enhance the strength of the second opening 251 and the second wall 25, further reducing the risk of cracking of the housing 211 in the area near the welding position of the housing 211 and the end cap 212. At the same time, multiple second thickened areas 251a are arranged circumferentially at intervals along the opening 211a, which facilitates the reduction of the demolding difficulty of the housing 211 during processing and manufacturing, and reduces the manufacturing difficulty of the battery cell 20.

[0200] According to some embodiments of this application, the area of ​​the outer surface of the second wall 25 is smaller than the area of ​​the outer surface of the first wall 24.

[0201] In the above scheme, the area of ​​the outer surface of the second wall 25 is smaller than the area of ​​the outer surface of the first wall 24. The first wall 24 can be the large surface of the shell 211. The setting of the first thickened area 241a and the setting of the second thickened area 251a can reduce the risk of cracking of the shell 211 in the area near the welding position of the shell 211 and the end cover 212.

[0202] According to some embodiments of this application, along the circumferential direction of the opening, the distance between two adjacent second thickened areas is L4, which satisfies 2mm≤L4≤15mm.

[0203] Optionally, L4 can be, but is not limited to, 2mm, 3mm, 4mm, 5mm, 6mm, 7mm, 8mm, 9mm, 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, etc.

[0204] In the above scheme, the distance between two adjacent second thickened areas 251a satisfies the above relationship. On the one hand, it can improve the strength of the second opening 251, and on the other hand, it can reduce the demolding difficulty during the processing and manufacturing of the shell 211, making demolding easier.

[0205] Optionally, 5mm≤L1≤10mm.

[0206] According to some embodiments of this application, along the third direction, the size of the second wall 25 is L5, and the size of the second thickened area 251a is L6, satisfying 0.1*L5≤L6<0.5*L5, and the third direction is parallel to the thickness direction X of the first wall.

[0207] In the above scheme, the dimensions of the second thickened area 251a in the third direction satisfy the above relationship, which can improve the strength of the second opening 251 on the one hand, and reduce the demolding difficulty during the processing and manufacturing of the shell 211 on the other hand.

[0208] Optionally, 0.2*L5≤L6≤0.25*L5.

[0209] According to some embodiments of this application, the thickness of the second body portion 252 is t4, and the maximum thickness of the second thickened region 251a is t5, satisfying that 0.05mm≤t5-t4≤t4.

[0210] In the above scheme, the difference between the maximum thickness of the second thickened region 251a and the thickness of the second body part 252 satisfies the above relationship. On the one hand, the second thickened region 251a has high strength, and on the other hand, the second thickened region 251a occupies a small space, so that the battery cell 20 can have a high energy density.

[0211] Optionally, 0.2mm≤t5-t4≤0.8*t4.

[0212] According to some embodiments of this application, 0.25mm ≤ t4 ≤ 1.25mm.

[0213] According to some embodiments of this application, 0.85mm ≤ t5 ≤ 1.85mm.

[0214] Please refer to Figure 14, which is a schematic diagram of the assembly of the end cap and the second opening provided in some embodiments of this application. According to some embodiments of this application, the second body portion 252 has a third surface 252a facing the interior of the battery cell 20, and a second thickened region 251a protrudes from the third surface 252a.

[0215] In the above scheme, the second thickened area 251a protrudes from the third surface 252a, so that the side of the second thickened area 251a away from the inside of the battery cell 20 can be parallel to the side of the second body portion 252 away from the inside of the battery cell 20, thereby reducing the space occupied by the second thickened area 251a on the outside of the battery cell 20 and reducing the risk of interference between the second thickened area 251a and other components.

[0216] Please refer to Figure 14, and further to Figures 15 and 16. Figure 15 is a structural schematic diagram of the end cap provided in some embodiments of this application, and Figure 16 is a partial enlarged view of point F in Figure 15. According to some embodiments of this application, the end cap 212 is disposed within the opening 211a. The end cap 212 has a second side surface 212c facing the second opening 251. The second side surface 212c is provided with a second recessed area 212d corresponding to the second thickened area 251a. At least a portion of the second thickened area 251a is located within the second recessed area 212d.

[0217] The second recessed area 212d refers to the area of ​​the end cap 212 corresponding to the second thickened area 251a. The second recessed area 212d is a recess formed on the second side surface 212c. In the thickness direction of the second wall 25, the second recessed area 212d is recessed relative to other areas in a direction away from the second wall 25, so that at least a portion of the second thickened area 251a is located in the second recessed area 212d.

[0218] In the above scheme, the setting of the second recessed area 212d facilitates the cooperation between the end cover 212 and the second wall 25, and facilitates the connection between the end cover 212 and the housing 211.

[0219] According to some embodiments of this application, the thickness of the first transition region 241b may be greater than the thickness of the first body portion 242.

[0220] According to some embodiments of this application, the end cap 212 has a second surface 212e facing away from the interior of the battery cell 20, and the maximum distance between the end of the second thickened region 251a facing away from the second surface 212e and the second surface 212e along the first direction Z is less than or equal to 10 mm.

[0221] The maximum distance between the end of the second thickened region 251a that is away from the second surface 212e and the second surface 212e is h2, which satisfies h2≤10mm.

[0222] The maximum distance between the end of the second thickened region 251a away from the second surface 212e and the second surface 212e refers to the maximum distance between the end of the second thickened region 251a near the second body portion 252 and the second surface 212e along the first direction Z.

[0223] In the above scheme, along the first direction Z, the maximum distance between the end of the second thickened area 251a that is away from the second surface 212e and the second surface 212e is less than or equal to 10mm. This not only makes the second opening 251 have high strength to reduce the risk of the shell 211 cracking near the welding position of the shell 211 and the end cap 212, but also makes it easy for the shell 211 to be demolded during the processing and manufacturing process, which is convenient for processing and manufacturing.

[0224] According to some embodiments of this application, a plurality of second thickened regions 251a include a second central thickened region, which extends along a third direction parallel to the thickness direction X of the first wall, and the second central thickened region passes through the center of the second wall 25 in the third direction.

[0225] The center of the second central thickened area in the third direction may coincide with the center of the second wall 25 in the third direction, or the center of the second central thickened area in the third direction may not coincide with the center of the second wall 25 in the third direction.

[0226] Among the multiple second thickened regions 251a, some of the second thickened regions 251a can be distributed at both ends of the second middle thickened region in the third direction, so that the second wall 25 is thickened at multiple positions in the third direction, thereby improving the strength of the second opening 251.

[0227] In the above scheme, the second central thickened area passes through the center of the second wall 25 in the third direction, which makes the area near the center of the second wall 25 in the third direction stronger, which helps to reduce the risk of cracking of the shell 211 in the area near the welding position of the shell 211 and the end cover 212.

[0228] According to some embodiments of this application, a plurality of second thickened regions 251a are centrally symmetrically arranged about the second wall 25 in the third direction.

[0229] In some embodiments, one of the plurality of second thickened regions 251a may be located at the center of the third direction through the second wall 25. For example, the plurality of second thickened regions 251a may include a second central thickened region, which may be located at the center of the third direction through the second wall 25.

[0230] In some embodiments, at least one of the second transition zones 251b may pass through the second wall 25 at the center of the third-party upward direction.

[0231] In the above scheme, the arrangement of multiple second thickened areas 251a makes the second opening 251 have higher strength and improves the welding strength between the second opening 251 and the end cap 212.

[0232] According to some embodiments of this application, the thickness of the first transition region 241b is equal to the thickness of the first body portion 242.

[0233] In the above scheme, the thickness of the first transition region 241b is equal to the thickness of the first body part 242, which facilitates processing and manufacturing.

[0234] According to some embodiments of this application, the thickness of the second transition region 251b is equal to the thickness of the second body portion 252.

[0235] In the above scheme, the thickness of the second transition region 251b is equal to the thickness of the second body part 252, which facilitates processing and manufacturing.

[0236] Referring to Figure 4, according to some embodiments of this application, there are two first walls 24, which are disposed opposite each other in a third direction, and the third direction is parallel to the thickness direction X of the first wall. The housing 211 also includes a bottom wall 26 and two second walls 25 disposed opposite each other in a second direction Y. The two first walls 24 and the two second walls 25 form an opening 211a. Along the first direction Z, the bottom wall 26 is disposed opposite to the opening 211a, and the first direction Z, the second direction Y and the third direction are perpendicular to each other.

[0237] The first wall 24 is connected to two second walls 25 at both ends in the second direction Y, and the second wall 25 is connected to two first walls 24 at both ends in the third direction Z; one end of the first wall 24 is connected to the bottom wall 26 in the first direction Z, one end of the second wall 25 is connected to the bottom wall 26 in the first direction Z, and the other end of the first wall 24 and the other end of the second wall 25 in the first direction Z form an opening 211a.

[0238] In some embodiments, the two first walls 24, the two second walls 25, and the bottom wall 26 are integrally formed.

[0239] In the above scheme, the bottom wall 26 is arranged opposite to the opening 211a. During the assembly of the battery cell 20, the bottom wall 26 can support the electrode assembly 22 to facilitate the positioning of the electrode assembly 22.

[0240] According to some embodiments of this application, the housing 211 has a prismatic structure, the housing 211 has two openings 211a, and the number of end caps 212 is two, with the two end caps 212 respectively closing the two openings 211a.

[0241] When the housing 211 has a prismatic structure, the battery cell 20 can be a square battery. In other embodiments, the housing 211 can be a hexagonal prism, an octagonal prism, etc.

[0242] When the positive electrode tab and the negative electrode tab are disposed at both ends of the electrode assembly, the housing 211 has two openings 211a, and the positive electrode terminal and the negative electrode terminal can be disposed on the two end caps 212 respectively, so as to be electrically connected to the positive electrode tab and the negative electrode tab respectively, so as to facilitate the charging and discharging of the battery cell 20.

[0243] In the above scheme, openings 211a are respectively provided at both ends of the shell 211, and the first wall 24 is provided at both ends in the first direction Z. The first openings 241 at each end in the first direction Z form the corresponding opening 211a. The provision of the first thickened area 241a can enhance the strength of the shell 211 near the opening 211a, thereby reducing the risk of cracking of the shell 211 near the welding area between the shell 211 and the end cap 212.

[0244] According to some embodiments of this application, this application also provides a battery 100, which includes a battery cell 20 as provided in any of the above embodiments.

[0245] Please refer to Figures 17 to 19. Figure 17 is a schematic diagram of the assembly of an end plate and multiple battery cells according to some embodiments of this application. Figure 18 is a schematic diagram of the assembly of an end plate and battery cells according to some embodiments of this application. Figure 19 is a partial enlarged view of point G in Figure 18. According to some embodiments of this application, there are multiple battery cells 20, which are stacked along a third direction to form a battery cell group 20a. The battery 100 also includes an end plate 30, which is disposed at the end of the battery cell group 20a along a third direction. In the direction from the first body portion 242 to the first opening portion 241, at least a portion of the first opening portion 241 extends beyond the end plate 30.

[0246] Multiple battery cells 20 are stacked along a third direction. Along the third direction, an end plate 30 is disposed at the end of the battery cell group 20a. The end plate 30 is connected to the battery cell 20 located at the end of the battery cell group 20a in the third direction. The end plate 30 can limit the battery cell 20 at that end and constrain the deformation of the battery cell 20.

[0247] In the above scheme, the end plate 30 is disposed at the end of the multiple battery cells 20 in the third direction. The end plate 30 has a large connection area with the housing 211 of the adjacent battery cell 20 to form a constraint on the housing 211 and reduce the risk of cracking of the housing 211 in the area near the welding position of the housing 211 and the end cap 212.

[0248] According to some embodiments of this application, the end plate 30 is disposed facing the first wall 24.

[0249] In the above scheme, the end plate 30 is disposed facing the first wall 24, and the end plate 30 and the first body part 242 have a large contact area. During the charging and discharging cycle of the battery cell 20, the end plate 30 can constrain the first wall 24 to reduce the risk of cracking of the housing 211 in the area near the welding position of the housing 211 and the end cover 212.

[0250] According to some embodiments of this application, this application also provides an electrical device, which includes a battery cell 20 or a battery 100 as provided in any of the above embodiments, the battery cell 20 or the battery 100 being used to provide electrical energy.

[0251] The electrical equipment can be any of the above-mentioned systems or devices that use battery cells 20 or batteries, with battery cells 20 or batteries 100 used to provide electrical energy.

[0252] According to some embodiments of this application, this application also provides an energy storage device, which includes a battery cell 20 or a battery 100 as provided in any of the above embodiments.

[0253] According to some embodiments of this application, referring to Figures 3 to 14, this application provides a battery cell 20, which is cuboid in shape. The battery cell 20 includes a housing 21 and an electrode assembly 22, with the electrode assembly 22 disposed within the housing 21. The housing 21 includes a shell 211 and an end cap 212. The shell 211 has an opening 211a, which is closed by the end cap 212. The shell 211 includes two first walls 24 disposed opposite each other along a third direction and two second walls 25 disposed opposite each other along a second direction Y. The two ends of the first walls 24 in the second direction Y are respectively connected to the two second walls 25. The area of ​​the outer surface of the first wall 24 is larger than the area of ​​the outer surface of the second wall 25. The first wall 24 includes a first opening 241 and a first body portion 242 sequentially disposed along a first direction Z, which is parallel to the thickness direction of the end cap 212. The first opening 241 is closer to the opening 211a relative to the first body portion 242, and the end cap 212 is welded to the first opening 241. The first opening 241 includes a plurality of first thickened regions 241a and at least one first transition region 241b. The plurality of first thickened regions 241a are spaced apart circumferentially along the opening 211a. Any two adjacent first thickened regions 241a are connected by the first transition region 241b. The maximum thickness of the first thickened region 241a is greater than the thickness of the first body portion 242, and the maximum thickness of the first thickened region 241a is greater than the thickness of the first transition region 241b. Along the circumferential direction of the opening 211a, the distance between two adjacent first thickened regions 241a is L1, which satisfies 2mm ≤ L1 ≤ 15mm.

[0254] According to the embodiments of this application, the battery cell 20 has a thickened first thickened region 241a, which enhances the thickness of the first opening 241, giving the first opening 241 higher strength and reducing the risk of cracking in the area near the welding position of the housing 211 and the end cap 212. Multiple thickened regions 241a are spaced apart along the circumference of the opening 211a, which improves the strength of the first opening 241 while reducing the difficulty of demolding during the processing and manufacturing of the housing 211, thus reducing the manufacturing difficulty of the battery cell 20.

[0255] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

A battery cell, characterized in that, include: An outer casing includes a housing and an end cap. The housing has an opening. The housing includes a first wall, which includes a first opening and a first body portion arranged sequentially along a first direction. The first direction is parallel to the thickness direction of the end cap. The first opening is close to the opening relative to the first body portion. The end cap is welded to the first opening to close the opening. The first opening includes a plurality of first thickened regions and at least one first transition region. The plurality of first thickened regions are spaced apart circumferentially along the opening. Two adjacent first thickened regions are connected through the first transition region. The maximum thickness of the first thickened region is greater than the thickness of the first body portion, and the maximum thickness of the first thickened region is greater than the thickness of the first transition region. The battery cell according to claim 1 is characterized in that, Along the circumference of the opening, the distance between any two adjacent first thickened areas is greater than or equal to 2 mm, and the distance between any two adjacent first thickened areas is less than or equal to 15 mm. The battery cell according to claim 1 or 2 is characterized in that, Along the second direction, the size of the first thickened area is greater than or equal to 0.1 times the size of the first wall, and the size of the first thickened area is less than or equal to 0.5 times the size of the first wall. The second direction, the first direction, and the thickness direction of the first wall are perpendicular to each other. The battery cell according to any one of claims 1-3 is characterized in that, The thickness direction of the first thickened area is parallel to the thickness direction of the first wall. The difference between the maximum thickness of the first thickened area and the thickness of the first body part is greater than or equal to 0.05 mm. The difference between the maximum thickness of the first thickened area and the thickness of the first body part is less than or equal to the thickness of the first body part. The battery cell according to claim 4 is characterized in that, The maximum thickness of the first thickened area is greater than or equal to 0.25 mm, and the maximum thickness of the first thickened area is less than or equal to 2.4 mm. The battery cell according to claim 4 or 5 is characterized in that, The thickness of the first body part is greater than or equal to 0.2 mm, and the thickness of the first body part is less than or equal to 1.2 mm. The battery cell according to any one of claims 1-6 is characterized in that, The first body portion has a first surface facing the interior of the battery cell, and the first thickened area protrudes from the first surface. The battery cell according to claim 7 is characterized in that, The end cap is disposed within the opening, and the end cap has a first side facing the first opening. The first side has a first recessed area corresponding to the first thickened area, and at least a portion of the first thickened area is located within the first recessed area. The battery cell according to any one of claims 1-8 is characterized in that, The end cap has a second surface facing away from the interior of the battery cell, and along the first direction, the maximum distance between the end of the first thickened region facing away from the second surface and the second surface is less than or equal to 10 mm. The battery cell according to any one of claims 1-9 is characterized in that, The plurality of first thickened areas include a first central thickened area, which extends along a second direction and passes through the center of the first wall in the second direction. The second direction, the first direction, and the thickness direction of the first wall are perpendicular to each other. The battery cell according to any one of claims 1-10 is characterized in that, Multiple first thickened zones are centrally symmetrically arranged about the first wall in a second direction, and the second direction, the first direction, and the thickness direction of the first wall are perpendicular to each other. The battery cell according to any one of claims 1-11 is characterized in that, The housing further includes a second wall connected to the first wall, and an end cap connected to the second wall. The second wall includes a second opening and a second body portion spaced apart along the first direction. The second opening is close to the second body portion relative to the opening. The end cap is welded to the second opening. The second opening includes a plurality of second thickened areas and at least one second transition area. The plurality of second thickened areas are spaced apart circumferentially along the opening. Two adjacent second thickened areas are connected through the second transition area. The maximum thickness of the second thickened area is greater than the thickness of the second body portion, and the maximum thickness of the second thickened area is greater than the thickness of the second transition area. The battery cell according to claim 12 is characterized in that, The area of ​​the outer surface of the second wall is smaller than the area of ​​the outer surface of the first wall. The battery cell according to claim 12 or 13 is characterized in that, The second body portion has a third surface facing the interior of the battery cell, and the second thickened region protrudes from the third surface. The battery cell according to claim 14 is characterized in that, The end cap is disposed within the opening, and the end cap has a second side facing the second opening. The second side has a second recessed area corresponding to the second thickened area, and at least a portion of the second thickened area is located within the second recessed area. The battery cell according to any one of claims 1-15 is characterized in that, The thickness of the first transition zone is equal to the thickness of the first body portion. The battery cell according to any one of claims 1-16 is characterized in that, The number of first walls is two, and the two first walls are arranged opposite each other in a third direction, which is parallel to the thickness direction of the first walls; the shell also includes a bottom wall and two second walls arranged opposite each other in a second direction, the two first walls and the two second walls forming the opening, and the bottom wall is arranged opposite each other in the first direction, the first direction, the second direction and the third direction are perpendicular to each other. The battery cell according to any one of claims 1-17 is characterized in that, The housing has a prismatic structure and two openings. There are two end caps, which respectively close the two openings. A battery characterized in that, Includes the battery cell as described in any one of claims 1-18. The battery according to claim 19 is characterized in that, The number of battery cells is multiple, and the multiple battery cells are stacked along a third direction to form a battery cell group. The third direction is parallel to the thickness direction of the first wall. The battery also includes an end plate. Along the third direction, the end plate is disposed at the end of the battery cell group. In the direction from the first body portion to the first opening portion, at least a portion of the first opening portion extends beyond the end plate. An electrical appliance, characterized in that, Includes a battery cell as described in any one of claims 1-18 or a battery as described in any one of claims 19-20, wherein the battery cell or the battery is used to provide electrical energy. An energy storage device, characterized in that, Includes a battery cell as described in any one of claims 1-18 or a battery as described in any one of claims 19-20.

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