Battery cell, battery, electric device, and energy storage apparatus

Abstract

A battery cell (20), a battery (100), an electric device, and an energy storage apparatus. The battery cell (20) comprises a casing (21). The casing (21) comprises a shell (211) and an end cover (212). An opening (211a) is formed in the shell (211). The shell (211) comprises a first wall (24). The first wall (24) comprises a first opening part (241) and a first body part (242) sequentially arranged in 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 an opening (211a) with respect to the first body part (242). The end cover (212) is welded to the first opening part (241) to seal the opening (211a). 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 at intervals in a circumferential direction of the opening (211a). Two adjacent first thickening areas (241a) are connected by means of the first transition area (241b). The maximum thickness of the first thickening areas (241a) is greater than the thickness of the first body part (242), and the maximum thickness of the first thickening areas (241a) is greater than the thickness of the first transition area (241b). The present application can improve the reliability of the battery cell (20).

Description

Battery cells, batteries, electrical equipment and energy storage devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application CN202420292359.X, filed on February 18, 2024, entitled “Battery Cell, Battery, Electrical Equipment and Energy Storage Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, an electrical device, and an energy storage device. Background Art

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

[0005] During the manufacturing process of batteries, battery reliability is an issue that cannot be ignored. Therefore, how to improve battery reliability is a technical problem that needs to be solved urgently in battery technology.

[0006] Summary of the Invention

[0007] The present 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 solutions:

[0009] In a first aspect, an embodiment of the present application provides a battery cell, which includes a housing. The housing includes a shell and an end cap. The shell has an opening. The shell includes a first wall. The first wall includes a first opening portion and a first main body portion arranged in sequence along a first direction. The first direction is parallel to the thickness direction of the end cap. The first opening portion is close to the opening relative to the first main body portion. The end cap is welded to the first opening portion to close the opening. The first opening portion includes a plurality of first thickened regions and at least one first transition region. The plurality of first thickened regions are arranged at intervals along the circumference of the opening. Two adjacent first thickened regions are connected by the first transition region. The maximum thickness of the first thickened region is greater than the thickness of the first main body portion. The maximum thickness of the first thickened region is greater than the thickness of the first transition region.

[0010] In the battery cell of the embodiment of the present application, multiple first thickened regions are spaced apart along the circumference of the opening. The maximum thickness of the first thickened regions is greater than the thickness of the first main body. The first thickened regions are thickened areas 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 weld between the housing and the end cap, and improve the reliability of the battery cell. Furthermore, the multiple first thickened regions are spaced apart along the circumference of the opening, which can reduce the difficulty of demolding the housing during processing and manufacturing, thereby reducing the difficulty of manufacturing the battery cell.

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

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

[0013] According to some embodiments of the present 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 difficulty of demolding during shell processing and manufacturing can be reduced.

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

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

[0017] According to some embodiments of the present 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 zone satisfies the above relationship. On the one hand, when the maximum thickness of the first thickened zone is greater than or equal to 0.25 mm, the first thickened zone has higher strength. On the other hand, when the maximum thickness of the first thickened zone is less than or equal to 2.4 mm, the space occupied by the first thickened zone is smaller.

[0019] According to some embodiments of the present 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 main body is greater than or equal to 0.2 mm, the first main body has higher strength; on the other hand, when the thickness of the first main body is less than or equal to 1.2 mm, the first main body occupies less space in the thickness direction of the first wall, so that the battery cell can have a higher energy density.

[0021] According to some embodiments of the present application, 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.

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

[0023] According to some embodiments of the present application, the end cover is arranged in the opening, and the end cover has a first side facing the first opening portion. 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 solution, at least a portion of the first thickened area is located in the first recessed area, so as to facilitate the cooperation between the end cover and the first wall and the connection between the end cover and the shell.

[0025] According to some embodiments of the present application, the end cap has a second surface facing away from the interior of the battery cell, and along the first direction, a maximum distance between an 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 solution, along the first direction, the maximum distance between the end of the first thickened zone facing away from the second surface and the second surface is less than or equal to 10 mm, which not only makes the first opening portion have higher strength to reduce the risk of cracking of the shell near the welding position of the shell and the end cover, but also facilitates the demolding of the shell during the processing and manufacturing process, thereby facilitating processing and manufacturing.

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

[0028] In the above solution, the first central thickened area passes through the center of the first wall in the second direction, so that the strength of the area near the center of the first wall in the second direction is higher, which facilitates reducing the risk of cracking of the shell in the area near the welding position of the shell and the end cover.

[0029] According to some embodiments of the present application, the plurality of first thickened regions are symmetrically arranged about the center of the first wall in the 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 solution, the arrangement of the multiple first thickened areas enables the first opening to have a higher strength, thereby improving the welding strength between the first opening and the end cover.

[0031] According to some embodiments of the present application, the shell also includes a second wall, the second wall is connected to the first wall, the end cover is connected to the second wall, the second wall includes a second opening portion and a second main body portion arranged at intervals along the first direction, the second opening portion is close to the opening relative to the second main body portion, and the end cover is welded to the second opening portion; the second opening portion includes a plurality of second thickened areas and at least one second transition area, the plurality of second thickened areas are arranged at intervals along the circumference of the opening, two adjacent second thickened areas are connected by the second transition area, the maximum thickness of the second thickened area is greater than the thickness of the second main body portion, and the maximum thickness of the second thickened area is greater than the thickness of the second transition area.

[0032] In the above solution, the second wall is positioned adjacent to the first wall and has a similar structure. The provision of the second thickened region enhances the strength of the second opening, thereby strengthening the second wall and further reducing the risk of cracking in the area surrounding the weld between the housing and the end cap. Furthermore, the provision of multiple second thickened regions spaced circumferentially along the opening reduces the difficulty of demolding the housing during manufacturing, thereby reducing the difficulty of manufacturing the battery cells.

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

[0035] According to some embodiments of the present application, the second body portion has a third surface facing the interior of the battery cell, and the second thickened area 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 facing away from the interior of the battery cell can be parallel to the side of the second main body facing away from the interior of the battery cell, so as to reduce the space occupied by the second thickened area on the outside of the battery cell and reduce the risk of interference between the second thickened area and other components.

[0037] According to some embodiments of the present application, the end cover is arranged in the opening, and the end cover has a second side surface facing the second opening portion. The second side surface is provided with a second recessed area corresponding to the second thickened area, and at least a portion of the second thickened area is located in the second recessed area.

[0038] In the above solution, the provision of the second recessed area can facilitate the cooperation between the end cover and the second wall, and facilitate the connection between the end cover and the shell.

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

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

[0041] According to some embodiments of the present application, there are two first walls, and the two first walls are arranged opposite to each other in a third direction, and the third direction is parallel to the thickness direction of the first walls; the shell also includes a bottom wall and two second walls arranged opposite to each other in the second direction, the two first walls and the two second walls form an opening, and along the first direction, the bottom wall and the opening are arranged opposite to each other, and the first direction, the second direction and the third direction are perpendicular to each other.

[0042] In the above solution, the bottom wall is arranged opposite to the opening. During the assembly of the battery cell, the bottom wall can support the electrode assembly to facilitate positioning of the electrode assembly.

[0043] According to some embodiments of the present application, the shell is a prismatic structure, the shell has two openings, and there are two end covers, which respectively close the two openings.

[0044] In the above solution, the shell has two openings, and the two end covers respectively close the two openings to facilitate assembly of the electrode assembly and the shell.

[0045] In a second aspect, an embodiment of the present application further provides a battery, which includes a battery cell provided in any of the above embodiments.

[0046] According to some embodiments of the present application, there are multiple battery cells, and the multiple battery cells are stacked along a third direction to form a battery cell group, and the third direction is parallel to the thickness direction of the first wall. The battery also includes an end plate, and along the third direction, the end plate is arranged at the end of the battery cell group, along the direction of the first main body portion pointing to the first opening portion, and at least a portion of the first opening portion exceeds the end plate.

[0047] In the above solution, the end plate is arranged at the end of the battery cell group in the third direction, and the end plate has a large connection area with the shell of the adjacent battery cell to form a constraint on the shell, thereby reducing the risk of cracking of the shell in the area near the welding position of the shell and the end cover.

[0048] In a third aspect, an embodiment of the present application further provides an electrical device, which includes a battery cell or battery as provided in any of the above embodiments, and the battery cell or battery is used to provide electrical energy.

[0049] In a fourth aspect, an embodiment of the present application further provides an energy storage device, which includes a battery cell or a battery as provided in any of the above embodiments.

[0050] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0052] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0053] FIG2 is an exploded schematic diagram of a battery provided in some embodiments of the present application;

[0054] FIG3 is an exploded schematic diagram of a battery cell provided in some embodiments of the present application;

[0055] FIG4 is a schematic diagram of the exploded structure of a housing provided in some embodiments of the present application;

[0056] FIG5 is a top view of a housing provided in some embodiments of the present application;

[0057] FIG6 is a cross-sectional view taken along the AA direction of FIG5 ;

[0058] FIG7 is a partial enlarged view of point B in FIG6;

[0059] FIG8 is a cross-sectional view taken along the CC direction of FIG5 ;

[0060] FIG9 is a partial enlarged view of point D in FIG8 ;

[0061] FIG10 is a schematic diagram of the assembly of the end cover and the first opening portion provided in some embodiments of the present application;

[0062] FIG11 is a schematic structural diagram of an end cap provided in some embodiments of the present application;

[0063] FIG12 is a partial enlarged view of point E in FIG11 ;

[0064] FIG13 is a schematic structural diagram of a housing provided in some other embodiments of the present application;

[0065] FIG14 is a schematic diagram of the assembly of the end cover and the second opening portion provided in some embodiments of the present application;

[0066] FIG15 is a schematic structural diagram of end covers provided in other embodiments of the present application;

[0067] FIG16 is a partial enlarged view of point F in FIG15 ;

[0068] FIG17 is a schematic diagram of the assembly of an end plate and multiple battery cells according to some embodiments of the present application;

[0069] FIG18 is a schematic diagram of the assembly of an end plate and a battery cell according to some embodiments of the present application;

[0070] FIG19 is a partial enlarged view of point G in FIG18 .

[0071] In the drawings, the drawings are not drawn to scale.

[0072] Markings: 100 - battery; 10 - housing; 11 - first sub-housing; 12 - second sub-housing; 20 - battery cell; 20a - battery cell group; 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 middle thickened area; 242-first main body; 242a-first surface; 25-second wall; 251-second opening; 251a-second thickened area; 251b-second transition area; 252-second main body; 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. DETAILED DESCRIPTION

[0073] The following detailed description of the embodiments of the present application is provided in conjunction with the accompanying drawings and examples. The following detailed description of the embodiments and the accompanying drawings are used to illustrate the principles of the present application, but are not intended to limit the scope of the present application, that is, the present application is not limited to the described embodiments.

[0074] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0075] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0076] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0077] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0078] The term "multiple" in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0079] In some embodiments, the battery may be a battery module. 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 may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0081] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0082] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0083] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0084] The battery cells may be, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, and the like.

[0085] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the 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 electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0088] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0089] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present 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 may be a metal foil or a composite current collector. For example, the metal foil may be silver-plated aluminum, silver-plated stainless steel, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel, or titanium.

[0092] In some embodiments, the negative electrode current collector has two opposite surfaces in its 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 for a battery that is well known in the art. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, lithium titanate, etc. The silicon-based material may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. The tin-based material may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, the present application is not limited to these materials, and other traditional materials that can be used as negative electrode active materials for batteries may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0094] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0095] As an example, the primary 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 positioned 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, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0097] In some embodiments, the electrode assembly is a wound structure, wherein the positive electrode sheet and the negative electrode sheet are wound into the wound structure.

[0098] In some embodiments, the electrode assembly is a laminate structure.

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

[0100] In some embodiments, the housing includes an end cap and a shell. The shell has an opening, and the end cap closes the opening to form a sealed space for accommodating the electrode assembly, electrolyte, and other substances. The shell may have one or more openings. One or more end caps may also be provided.

[0101] In some embodiments, the housing is provided with at least one electrode terminal, which is electrically connected to a tab of the electrode assembly. The electrode terminal may be directly connected to the tab or indirectly connected to the tab via an adapter. The electrode terminal may be provided on an end cap or on the housing.

[0102] In some embodiments, the housing is provided with an explosion-proof valve for releasing the internal pressure of the battery cell.

[0103] As an example, the battery cell can be a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square shell battery cell, a blade-shaped battery cell, a polygonal battery, and a polygonal battery such as a hexagonal battery. There is no special limitation in the embodiments of the present application.

[0104] The development of battery technology must take into account multiple design factors at the same time, such as energy density, discharge capacity, charge and discharge rate and other performance parameters. In addition, battery reliability must also be considered.

[0105] In some embodiments, a battery cell includes an outer shell and an electrode assembly, wherein the electrode assembly is disposed within the outer shell. The outer shell includes a shell and an end cap, wherein the shell has an opening and the end cap closes the opening. The end cap is usually welded to the shell. The high temperature during welding of the end cap and the shell easily causes a heat-affected zone to form on the portion of the end cap and the shell near the welding position, and the strength of the portion of the end cap and the shell in the heat-affected zone is relatively low. During the charge and discharge process of the battery cell, or when the electrode assembly produces a large amount of gas, or when the battery cell experiences thermal runaway, it is easy to cause the shell to crack in the area near the welding position of the shell and the end cap, resulting in damage to the shell and reducing the service life and reliability of the battery cell.

[0106] In view of this, an embodiment of the present application provides a technical solution, wherein a battery cell includes a housing, the housing including a shell and an end cap, the shell including a first wall, the first wall including an opening portion and a first main portion arranged in sequence along a first direction, the first direction being parallel to the thickness direction of the end cap, the first opening portion being closer to the opening relative to the first main portion, and the end cap being welded to the first opening portion to close the opening. The first opening portion includes a plurality of first thickened regions and at least one first transition region, the plurality of first thickened regions and the at least one first transition region being staggered along the circumference of the opening, the maximum thickness of the first thickened region being greater than the thickness of the first main portion, and the maximum thickness of the first thickened region being greater than the thickness of the first transition region, thereby increasing the strength of the first opening portion and reducing the risk of cracking of the shell in the area near the welding position between the shell and the end cap, thereby providing the battery cell with higher reliability.

[0107] In such a battery cell, the maximum thickness of the first thickened region is greater than the thickness of the first main body. The thickening treatment of the first thickened region provides greater strength, thereby 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 housing and the end cap, thereby improving the reliability of the battery cell. Furthermore, the multiple first thickened regions are spaced circumferentially along the opening, reducing the difficulty of demolding the housing during processing and manufacturing, thereby reducing the difficulty of manufacturing the battery cell.

[0108] The battery disclosed in the embodiments of the present application can be used, but is not limited to, in electrical equipment such as vehicles, ships, or aircraft. The battery disclosed in the present application can be used to form a power supply system for the electrical equipment.

[0109] The embodiments of the present application provide an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, an electric bicycle, an electric motorcycle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0110] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0111] Please refer to Figure 1, which is a schematic diagram of the structure of the vehicle provided in some embodiments of the present application. Vehicle 1000 can be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000, and the battery 100 can be provided at the bottom, head or tail of the vehicle 1000. The battery 100 can be used to power the vehicle 1000. For example, the battery 100 can be used as an operating power source for the vehicle 1000, for the circuit system of the vehicle 1000, such as for the working power requirements during the startup, navigation and operation of the vehicle 1000.

[0112] The vehicle 1000 may further 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, to meet the power requirements of the vehicle 1000 during startup, navigation, and driving.

[0113] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0114] Please refer to Figure 2, which is an exploded schematic diagram of a battery provided in some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 being housed within the housing 10. The housing 10 is used to provide a storage space for the battery cell 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first sub-housing 11 and a second sub-housing 12, the first sub-housing 11 and the second sub-housing 12 covering each other, and the first sub-housing 11 and the second sub-housing 12 jointly defining a storage space for accommodating the battery cell 20. The second sub-housing 12 can be a hollow structure with one end open, and the first sub-housing 11 can be a plate-shaped structure, with the first sub-housing 11 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 a storage space; the first sub-housing 11 and the second sub-housing 12 can also be hollow structures with one end open, with the open side of the first sub-housing 11 covering the open side of the second sub-housing 12.

[0115] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0116] The battery cell 20 may be a secondary battery or a primary battery; the battery cell 20 may also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto.

[0117] Please refer to Figure 3, which is an exploded schematic diagram of a battery cell provided in some embodiments of the present application. As shown in Figure 3, a battery cell 20 includes a housing 21, an electrode assembly 22, and other functional components. Housing 21 includes a shell 211 and an end cap 212. Shell 211 has an opening, and end cap 212 closes the opening, isolating the internal environment of 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 be used to 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 be of 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 a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0119] The end cap 212 is a component that covers the opening of the housing 211 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 212 can be adapted to the shape of the housing 211 to fit the housing 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap 212 from deforming when subjected to compression or collision, thereby providing the battery cell 20 with greater structural strength and improved reliability. Functional components such as electrode terminals 23 can be provided on the end cap 212. The electrode terminals 23 can be used to electrically connect to the electrode assembly 22 to output or input electrical energy to the battery cell 20. The end cap 212 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this is not particularly limited in the present embodiment. In some embodiments, an insulating structure can be provided on the inner side of the end cap 212 to isolate the electrical connection components within the housing 211 from the end cap 212 to reduce the risk of short circuits. For example, the insulating structure may be plastic, rubber, or the like.

[0120] The electrode assembly 22 is a component in the battery cell 20 where electrochemical reactions occur. One or more electrode assemblies 22 may be contained in the housing 211. The electrode assembly 22 is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The separator is used to separate the positive electrode sheet and the negative electrode sheet to avoid internal short circuits between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body.

[0121] Referring to FIG3 and further to FIG4 through FIG9 , FIG4 is a schematic diagram of an exploded structure of a housing provided in some embodiments of the present application, FIG5 is a top view of a housing provided in some embodiments of the present application, FIG6 is a cross-sectional view taken along the AA direction of FIG5 , FIG7 is a partial enlarged view of position B of FIG6 , FIG8 is a cross-sectional view taken along the CC direction of FIG5 , and FIG9 is a partial enlarged view of position D of FIG8 . According to some embodiments of the present application, a battery cell 20 is provided. The battery cell 20 includes a housing 21. The housing 21 includes a shell 211 and an end cap 212. The shell 211 has an opening 211a. The shell 211 includes a first wall 24. The first wall 24 includes a first opening portion 241 and a first body portion 242 arranged sequentially along a first direction Z. The first direction Z is parallel to the thickness direction of the end cap 212. The first opening portion 241 is closer to the opening 211a than the first body portion 242. The end cap 212 is welded to the first opening portion 241 to close the opening 211a. Among them, the first opening portion 241 includes multiple first thickened areas 241a and at least one first transition area 241b. The multiple first thickened areas 241a are arranged at intervals along the circumference of the opening 211a. Two adjacent first thickened areas 241a are connected by the first transition area 241b. The maximum thickness of the first thickened area 241a is greater than the thickness of the first main body portion 242, and the maximum thickness of the first thickened area 241a is greater than the thickness of the first transition area 241b.

[0122] In the figure, the direction indicated by the letter Z is the first direction, which is parallel to the thickness direction of the end cap 212 and can 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 the thickness direction X of the first wall can be parallel to the length direction of the battery cell 20.

[0123] In order to facilitate the distinction between the first opening portion 241 and the first body portion 242 , the dotted line F1 in FIG. 7 and FIG. 9 is a boundary line between the first opening portion 241 and the first body portion 242 .

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

[0125] Along the first direction Z, the first body portion 242 is farther away from the opening 211 a than the first opening portion 241 . The first opening portion 241 can enclose the opening 211 a so that the end cover 212 and the first opening portion 241 can be welded to close the opening 211 a .

[0126] Please refer to Figure 10, which is a schematic diagram of the assembly of the end cap and the first opening portion provided in some embodiments of the present application. In some embodiments, the end cap 212 and a portion of the first opening portion 241 are welded to form a first weld zone 210, which can be called a weld mark.

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

[0128] In some embodiments, the first thickened region 241a may have a uniform thickness or a variable thickness structure. When the first thickened region 241a has a uniform thickness, 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 has 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 zone 241a is a thickened structure, the thickness of the first thickened zone 241a can gradually decrease from the end away from the first main body portion 242 toward the end close to the first main body portion 242, and the area with the largest thickness of the first thickened zone 241a is located at the end away from the first main body portion 242.

[0130] In some embodiments, the first transition region 241b may be of uniform thickness or of variable thickness. Optionally, the first transition region 241b is of uniform thickness, 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 the at least one first transition region 241b are staggered along the circumference 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, the first transition region 241b, the first thickened regions 241a, the first transition region 241b, and the first thickened regions 241a are sequentially distributed along the circumference of the opening 211a.

[0132] In the battery cell 20 of the embodiment of the present application, multiple first thickened regions 241a are spaced apart along the circumference of the opening 211a. The maximum thickness of the first thickened regions 241a is greater than the thickness of the first main body 242. The first thickened regions 241a are thickened areas of the first opening 241. This improves the strength of the first opening 241 and the first wall 24, reduces the risk of cracking in the housing 211 near the weld between the housing 211 and the end cap 212, and improves the reliability of the battery cell 20. Furthermore, the spaced-apart arrangement of the multiple first thickened regions 241a along the circumference of the opening 211a reduces the difficulty of demolding the housing 211 during processing and manufacturing, thereby reducing the manufacturing difficulty of the battery cell 20.

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

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

[0135] 5 , according to some embodiments of the present application, along the circumference of the opening 211 a , the spacing between any two adjacent first thickened areas 241 a is greater than or equal to 2 mm, and the spacing between any two adjacent first thickened areas 241 a is less than or equal to 15 mm.

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

[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 portion 241. On the other hand, when L1≥2mm, it can reduce the difficulty of demolding during the processing and manufacturing of the shell 211, making demolding easier.

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

[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 solution, compared with L1<5mm, when L1≥5mm, the difficulty of demolding the shell 211 during processing and manufacturing is further reduced; compared with L1>10mm, when L1≤10mm, the first opening portion 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 cover 212.

[0142] Please refer to Figure 5. According to some embodiments of the present 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, the size of the first thickened area 241a is less than or equal to 0.5 times the size of the first wall 24, and 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 size of the first wall 24 is L2, and the size of the first thickened area 241 a is L3, satisfying 0.1*L2≤L3<0.5*L2.

[0144] In the figure, the direction indicated by letter Y may be the second direction, which may be parallel to the length direction of the battery cell 20 or the width direction of the battery cell 20. The second direction Y is a portion of the circumference 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 may 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 solution, the size of the first thickened area 241a in the second direction Y satisfies the above relationship, which can improve the strength of the first opening 241 on the one hand, and reduce the difficulty of demolding 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, processing and manufacturing are facilitated. When the dimensions of the first thickened regions 241a in the second direction Y are unequal, local thickening requirements can be met and the difficulty of shell demolding can be reduced.

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

[0150] Optionally, L3 may 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, further enhancing the strength of the first opening 241; compared with L3>0.25*L2, when L3≤0.25*L2, the difficulty of demolding during the processing and manufacturing of the shell 211 is further reduced.

[0152] Please refer to Figures 7 and 9. According to some embodiments of the present application, the thickness direction of the first thickened area 241a is parallel to the thickness direction X of the first wall, the difference between the maximum thickness of the first thickened area 241a and the thickness of the first main body portion 242 is greater than or equal to 0.05 mm, and the difference between the maximum thickness of the first thickened area 241a and the thickness of the first main body portion 242 is less than or equal to the thickness of the first main body portion 242.

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

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

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

[0156] In the above scheme, the difference between the maximum thickness of the first thickened area 241a and the thickness of the first main body 242 satisfies the above relationship. On the one hand, the first thickened area 241a has higher strength. On the other hand, the first thickened area 241a occupies less space, so that the battery cell 20 can have a higher energy density.

[0157] According to some embodiments of the present application, 0.2 mm ≤ 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 area 241a is further enhanced, so that the first opening portion 241 has higher strength; compared with t2-t1>0.8*t1, when t2-t1≤0.8*t1, the space occupied by the first thickened area 241a is further reduced, thereby reducing the impact on the energy density of the battery cell 20.

[0159] According to some embodiments of the present application, the maximum thickness of the first thickened region 241 a is greater than or equal to 0.25 mm, and the maximum thickness of the first thickened region 241 a 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 solution, the thickness of the first thickened area 241a satisfies the above relationship, which, on the one hand, makes the first thickened area 241a have higher strength, and on the other hand, makes the space occupied by the first thickened area 241a smaller.

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

[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<0.8mm, when t2≥0.8mm, the first thickened area 241a is further made to have higher strength, and the first opening portion 241 is further made to have higher strength; compared with t2>1.8mm, when t2≤1.8mm, the space occupied by the first thickened area 241a is further made smaller, thereby reducing the impact on the energy density of the battery cell 20.

[0165] According to some embodiments of the present 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] Alternatively, t1 may be, but is not limited to, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, etc.

[0167] In the above scheme, the thickness of the first main body portion 242 satisfies the above relationship. On the one hand, when the thickness of the first main body portion 242 is greater than or equal to 0.2 mm, the first main body portion 242 has higher strength; on the other hand, when the thickness of the first main body portion 242 is less than or equal to 1.2 mm, the first main body portion 242 occupies less space in the thickness direction X of the first wall, so that the battery cell 20 has a higher energy density.

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

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

[0170] In the above solution, compared with t1<0.6mm, when t1≥0.6mm, the first body portion 242 further has higher strength; compared with t1>1mm, when t1≤1mm, the first body further occupies smaller space, so that the battery cell 20 has higher energy density.

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

[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 facing away from the interior of the battery cell 20 can be parallel to the side of the first main body 242 facing away from the interior of the battery cell 20, so as to reduce the space occupied by the first thickened area 241a outside the battery cell 20 and reduce the risk of interference between the first thickened area 241a and other components.

[0173] Please refer to Figure 4 and further to Figures 11 and 12. Figure 11 is a schematic structural diagram of an end cap provided in some embodiments of the present application, and Figure 12 is a partial enlarged view of point E in Figure 11. According to some embodiments of the present application, the end cap 212 is disposed within 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 within the first recessed area 212b.

[0174] The end cover 212 is disposed in the opening 211 a , and a side surface of the end cover 212 is connected to an inner surface of the shell 211 , so as to facilitate welding of the end cover 212 and the shell 211 .

[0175] The first recessed area 212b refers to the area of ​​the end cover 212 corresponding to the first thickened area 241a. The first recessed area 212b is a recessed portion 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 within the first recessed area 212b.

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

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

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

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

[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 10 mm, which not only makes the first opening portion 241 have higher strength to reduce the risk of cracking of the shell 211 near the welding position of the shell 211 and the end cover 212, but also facilitates the demolding of the shell 211 during the processing and manufacturing process, thereby facilitating processing and manufacturing.

[0181] Please refer to Figure 4 and further to Figure 13, which is a schematic structural diagram of a housing provided in some other embodiments of the present application. According to some embodiments of the present application, the plurality of first thickened regions 241a include a first central thickened region 241c. The first central thickened region 241c 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 area 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 area 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 areas 241a, some of the first thickened areas 241a can be distributed at both ends of the first middle thickened area 241c in the second direction Y, so that multiple positions of the first wall 24 in the second direction Y are thickened to improve the strength of the first opening portion 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 higher, which facilitates reducing 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 the present application, the plurality of first thickened regions 241 a are symmetrically arranged about the center of 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 multiple first thickened regions 241a may pass through the center of the first wall 24 in the second direction Y. For example, the multiple first thickened regions 241a may include a first middle thickened region 241c, and the first middle thickened region 241c may pass through the center of the first wall 24 in the second direction Y.

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

[0188] In the above solution, the arrangement of the plurality of first thickened areas 241 a enables the first opening portion 241 to have a higher strength, thereby improving the welding strength between the first opening portion 241 and the end cover 212 .

[0189] Please refer to Figure 3 and further to Figure 13. According to some embodiments of the present application, the housing 211 further includes a second wall 25, which is connected to the first wall 24. The end cap 212 is connected to the second wall 25. The second wall 25 includes a second opening portion 251 and a second main body portion 252 spaced apart along the first direction Z. The second opening portion 251 is closer to the opening 211a than the second main body portion 252. The end cap 212 is welded to the second opening portion 251. The second opening portion 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 along the circumference of the opening 211a. Two adjacent second thickened regions 251a are connected by the second transition region 251b. The maximum thickness of the second thickened regions 251a is greater than the thickness of the second main body portion 252, and the maximum thickness of the second thickened regions 251a is greater than the thickness of the second transition region 251b.

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

[0191] The second wall 25 is arranged adjacent to the first wall 24. The number of the second walls 25 can be two, and the number of the first walls 24 can be two. The two second walls 25 are arranged at intervals along the second direction Y, and the two first walls 24 are arranged at intervals 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 211 a than the second opening portion 251 . The second opening portion 251 can enclose the opening 211 a so that the end cover 212 can be connected to the second opening portion 251 to close the opening 211 a .

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

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

[0195] In some embodiments, the second thickened region 251a may have a uniform thickness or a variable thickness structure. When the second thickened region 251a has a uniform thickness, 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 has a variable thickness structure, the maximum thickness of the second thickened region 251a is the thickness at the position where the second thickened region 251a has the maximum thickness.

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

[0197] In some embodiments, the second transition region 251b may be of a uniform thickness or a variable thickness structure. Optionally, the second transition region 251b is of a uniform 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 the at least one second transition region 251b are 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, the second transition region 251b, and the second thickened region 251a are sequentially distributed along the circumference of the opening 211a.

[0199] In the above embodiment, the second wall 25 is disposed adjacent to the first wall 24 and has a similar structure to the first wall 24. The provision of the second thickened region 251a enhances the strength of the second opening 251 and the second wall 25, further reducing the risk of cracking of the housing 211 near the weld between the housing 211 and the end cap 212. Furthermore, the provision of multiple second thickened regions 251a at intervals along the circumference of the opening 211a facilitates easier demolding of the housing 211 during fabrication, thereby reducing the manufacturing difficulty of the battery cell 20.

[0200] According to some embodiments of the present 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 the present application, along the circumference 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 solution, 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 portion 251, and on the other hand, it can reduce the difficulty of demolding during the processing and manufacturing of the shell 211, making demolding easier.

[0205] Optionally, 5mm≤L1≤10mm.

[0206] According to some embodiments of the present 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 solution, the size of the second thickened area 251a in the third direction satisfies the above relationship, which can improve the strength of the second opening 251 on the one hand, and reduce the difficulty of demolding 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 the present application, the thickness of the second body portion 252 is t4, and the maximum thickness of the second thickened area 251 a is t5, satisfying 0.05 mm ≤ t5 - t4 ≤ t4.

[0210] In the above solution, the difference between the maximum thickness of the second thickened area 251a and the thickness of the second main body 252 satisfies the above relationship. On the one hand, the second thickened area 251a has higher strength. On the other hand, the second thickened area 251a occupies less space, so that the battery cell 20 can have a higher energy density.

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

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

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

[0214] Please refer to Figure 14, which is a schematic diagram of the assembly of the end cap and the second opening according to some embodiments of the present application. According to some embodiments of the present application, the second body portion 252 has a third surface 252a facing the interior of the battery cell 20, and the second thickened area 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 facing away from the interior of the battery cell 20 can be parallel to the side of the second main body 252 facing away from the interior of the battery cell 20, so as to reduce the space occupied by the second thickened area 251a outside the battery cell 20 and reduce 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 schematic structural diagram of an end cap provided in some other embodiments of the present application, and Figure 16 is a partial enlarged view of point F in Figure 15. According to some embodiments of the present 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 portion 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 cover 212 corresponding to the second thickened area 251a. The second recessed area 212d is a recessed portion 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 within the second recessed area 212d.

[0218] In the above solution, the provision of the second recessed area 212 d can facilitate the cooperation between the end cover 212 and the second wall 25 , and facilitate the connection between the end cover 212 and the housing 211 .

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

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

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

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

[0223] In the above scheme, along the first direction Z, the maximum distance between the end of the second thickened area 251a facing away from the second surface 212e and the second surface 212e is less than or equal to 10 mm, which not only makes the second opening portion 251 have higher strength to reduce the risk of cracking of the shell 211 near the welding position of the shell 211 and the end cover 212, but also facilitates the demolding of the shell 211 during the processing and manufacturing process, thereby facilitating processing and manufacturing.

[0224] According to some embodiments of the present application, multiple second thickened regions 251a include a second central thickened region, which extends along a third direction, is parallel to the thickness direction X of the first wall, and 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 areas 251a, some of the second thickened areas 251a can be distributed at both ends of the second middle thickened area in the third direction, so that multiple positions of the second wall 25 in the third direction are thickened to improve the strength of the second opening portion 251.

[0227] In the above scheme, the second central thickened area passes through the center of the second wall 25 in the third direction, so that the strength of the area near the center of the second wall 25 in the third direction is higher, which facilitates reducing 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 the present application, the plurality of second thickened regions 251 a are symmetrically arranged about the center of the second wall 25 in the third direction.

[0229] In some embodiments, one of the multiple second thickened regions 251a may pass through the center of the second wall 25 in the third direction. For example, the multiple second thickened regions 251a may include a second middle thickened region, and the second middle thickened region may pass through the center of the second wall 25 in the third direction.

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

[0231] In the above solution, the arrangement of the plurality of second thickened areas 251 a enables the second opening portion 251 to have a higher strength, thereby improving the welding strength between the second opening portion 251 and the end cover 212 .

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

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

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

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

[0236] Referring to Figure 4 , according to some embodiments of the present application, there are two first walls 24 , which are disposed opposite each other in a third direction parallel to the thickness direction X of the first walls. The housing 211 further 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 define an opening 211 a. Along a first direction Z, the bottom wall 26 is disposed opposite the opening 211 a. 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 the two second walls 25 at both ends in the second direction Y, and the second wall 25 is connected to the two first walls 24 at both ends in the third direction; one end of the first wall 24 in the first direction Z is connected to the bottom wall 26, and one end of the second wall 25 in the first direction Z is connected to the bottom wall 26, and the other end of the first wall 24 in the first direction Z 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 solution, the bottom wall 26 is disposed opposite to the opening 211 a . During the assembly of the battery cell 20 , the bottom wall 26 can support the electrode assembly 22 to facilitate positioning of the electrode assembly 22 .

[0240] According to some embodiments of the present application, the shell 211 is a prismatic structure, the shell 211 has two openings 211 a , and there are two end covers 212 , which respectively close the two openings 211 a .

[0241] When the housing 211 is a prismatic structure, the battery cell 20 may be a square battery. In other embodiments, the housing 211 may be a hexagonal prism, an octagonal prism, or the like.

[0242] When the positive electrode tab and the negative electrode tab are arranged at both ends of the electrode assembly, the shell 211 has two openings 211a, and the positive electrode terminal and the negative electrode terminal can be respectively arranged on the two end covers 212 so as to be electrically connected to the positive electrode tab and the negative electrode tab respectively, so as to facilitate 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 first opening portions 241 are provided at both ends of the first wall 24 in the first direction Z. The first opening portions 241 at each end in the first direction Z surround the corresponding opening 211a. The setting of the first thickened area 241a can enhance the strength of the shell 211 near the opening 211a, so as to reduce the risk of cracking of the shell 211 near the welding area between the shell 211 and the end cover 212.

[0244] According to some embodiments of the present application, an embodiment of the present application further provides a battery 100 , which includes a battery cell 20 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 the present application. Figure 18 is a schematic diagram of the assembly of an end plate and a battery cell according to some embodiments of the present application. Figure 19 is a partial enlarged view of point G in Figure 18. According to some embodiments of the present application, there are multiple battery cells 20, and the multiple battery cells 20 are stacked along a third direction to form a battery cell group 20a. The battery 100 also includes an end plate 30. Along the third direction, the end plate 30 is disposed at an end of the battery cell group 20a, along the direction from the first body portion 242 to the first opening portion 241, and 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 arranged at the end of the battery cell group 20a. The end plate 30 is connected to the battery cell 20 at the end of the battery cell group 20a located in the third direction. The end plate 30 can limit the battery cell 20 at the end and restrain the deformation of the battery cell 20.

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

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

[0249] In the above scheme, the end plate 30 is arranged facing the first wall 24, and the end plate 30 has a large contact area with the first main body portion 242. During the charge and discharge cycle of the battery cell 20, the end plate 30 can constrain the first wall 24 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.

[0250] According to some embodiments of the present application, an electrical device is further provided, which includes a battery cell 20 or a battery 100 as provided in any of the above embodiments, and the battery cell 20 or the battery 100 is used to provide electrical energy.

[0251] The electrical equipment may be any of the above-mentioned systems or devices using the battery cell 20 or the battery 100 , and the battery cell 20 or the battery 100 is used to provide electrical energy.

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

[0253] According to some embodiments of the present application, referring to Figures 3 to 14 , embodiments of the present application provide a battery cell 20, which is rectangular. The battery cell 20 includes an outer shell 21 and an electrode assembly 22, which is disposed within the outer shell 21. The outer shell 21 includes a housing 211 and an end cap 212. The housing 211 has an opening 211a, and the end cap 212 seals the opening 211a. The housing 211 includes two first walls 24 arranged opposite each other along a third direction and two second walls 25 arranged opposite each other along a second direction Y. The first wall 24 is connected to the two second walls 25 at its ends in the second direction Y. The outer surface area of ​​the first wall 24 is greater than the outer surface area of ​​the second wall 25. The first wall 24 includes a first opening portion 241 and a first body portion 242, arranged sequentially along a first direction Z. The first direction Z is parallel to the thickness of the end cap 212. The first opening portion 241 is closer to the opening 211a than the first body portion 242, and the end cap 212 is welded to the first opening portion 241. The first opening portion 241 includes multiple first thickened regions 241a and at least one first transition region 241b. The multiple first thickened regions 241a are spaced apart along the circumference of 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 main body 242, and the maximum thickness of the first thickened region 241a is greater than the thickness of the first transition region 241b. Along the circumference of the opening 211a, the spacing between two adjacent first thickened regions 241a is L1, satisfying the following conditions: 2 mm ≤ L1 ≤ 15 mm.

[0254] In the battery cell 20 of the embodiment of the present application, the first thickened region 241a is thickened to increase the thickness of the first opening 241, providing greater strength and reducing the risk of cracking in the area of ​​the housing 211 near the weld between the housing 211 and the end cap 212. Multiple first thickened regions 241a are spaced apart along the circumference of the opening 211a, enhancing the strength of the first opening 241 while reducing the difficulty of demolding the housing 211 during fabrication, thereby simplifying the manufacturing of the battery cell 20.

[0255] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be substituted with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but encompasses all technical solutions within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: A housing comprising a shell and an end cap, wherein the shell has an opening and includes a first wall, the first wall including a first opening portion and a first body portion sequentially arranged along a first direction, the first direction being parallel to a thickness direction of the end cap, the first opening portion being closer to the opening relative to the first body portion, and the end cap being welded to the first opening portion to close the opening; In which, the first opening portion includes multiple first thickened areas and at least one first transition area, the multiple first thickened areas are arranged at intervals along the circumference of the opening, two adjacent first thickened areas are connected by the first transition area, the maximum thickness of the first thickened area is greater than the thickness of the first main body portion, and the maximum thickness of the first thickened area is greater than the thickness of the first transition area.

2. The battery cell according to claim 1, wherein: 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.

3. The battery cell according to claim 1 or 2, 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.

4. The battery cell according to any one of claims 1 to 3, 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 main body is greater than or equal to 0.05 mm, and the difference between the maximum thickness of the first thickened area and the thickness of the first main body is less than or equal to the thickness of the first main body.

5. The battery cell according to claim 4, 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.

6. The battery cell according to claim 4 or 5, characterized in that: 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.

7. The battery cell according to any one of claims 1 to 6, 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.

8. The battery cell according to claim 7, characterized in that The end cover is arranged in the opening, and has a first side surface facing the first opening. The first side surface 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.

9. The battery cell according to any one of claims 1 to 8, characterized in that: The end cover has a second surface facing away from the interior of the battery cell. Along the first direction, a maximum distance between an end of the first thickened region facing away from the second surface and the second surface is less than or equal to 10 mm.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The multiple first thickened areas include a first central thickened area, which extends along the 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.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The plurality of first thickened areas are symmetrically arranged about the center of the first wall in the second direction, and the second direction, the first direction and the thickness direction of the first wall are perpendicular to each other.

12. The battery cell according to any one of claims 1 to 11, characterized in that: The housing further includes a second wall connected to the first wall, the end cap connected to the second wall, the second wall including a second opening portion and a second main body portion spaced apart along the first direction, the second opening portion being closer to the opening relative to the second main body portion, and the end cap being welded to the second opening portion; The second opening portion includes multiple second thickened areas and at least one second transition area. The multiple second thickened areas are arranged at intervals along the circumference of the opening. Two adjacent second thickened areas are connected by the second transition area. The maximum thickness of the second thickened area is greater than the thickness of the second main body portion, and the maximum thickness of the second thickened area is greater than the thickness of the second transition area.

13. The battery cell according to claim 12, characterized in that: An area of ​​an outer surface of the second wall is smaller than an area of ​​an outer surface of the first wall.

14. The battery cell according to claim 12 or 13, characterized in that: The second body portion has a third surface facing the interior of the battery cell, and the second thickened area protrudes from the third surface.

15. The battery cell according to claim 14, characterized in that The end cover is arranged in the opening, and has a second side surface facing the second opening. The second side surface is provided with a second recessed area corresponding to the second thickened area, and at least a portion of the second thickened area is located in the second recessed area.

16. The battery cell according to any one of claims 1 to 15, characterized in that: The thickness of the first transition region is equal to the thickness of the first body portion.

17. The battery cell according to any one of claims 1 to 16, characterized in that: There are two first walls, and the two first walls are arranged opposite to each other in a third direction, and the third direction is parallel to the thickness direction of the first wall; The shell also includes a bottom wall and two second walls arranged opposite to each other in a second direction. The two first walls and the two second walls surround the opening. Along the first direction, the bottom wall and the opening are arranged opposite to each other. The first direction, the second direction and the third direction are perpendicular to each other.

18. The battery cell according to any one of claims 1 to 17, characterized in that: The shell is a prismatic structure, has two openings, and has two end covers, which respectively close the two openings.

19. A battery, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 18.

20. The battery according to claim 19, characterized in that There are multiple battery cells, 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 arranged at the end of the battery cell group, along the direction of the first main body pointing to the first opening, and at least a portion of the first opening exceeds the end plate.

21. An electrical device, characterized in that: The method comprises the battery cell according to any one of claims 1 to 18 or the battery according to any one of claims 19 to 20, wherein the battery cell or the battery is used to provide electrical energy.

22. An energy storage device, characterized in that: The method comprises the battery cell according to any one of claims 1 to 18 or the battery according to any one of claims 19 to 20.

Images