Battery monomer, battery, electric equipment and energy storage device

Abstract

The embodiment of the invention provides a battery monomer, a battery, electric equipment and an energy storage device. The single battery comprises a shell, the shell comprises a first wall and a second wall, the first wall and the second wall are welded to form a first welding area, the first wall comprises a first area and a second area which are arranged in the first direction, the first area is arranged close to the first welding area, the thickness of the first area is larger than that of the second area, and the first direction is parallel to the thickness direction of the second wall. According to the technical scheme provided by the embodiment of the invention, the reliability of the battery can be improved.

Description

Battery cells, batteries, electrical equipment and energy storage devices Technical Field

[0001] 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

[0002] 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.

[0003] 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.

[0004] Summary of the Invention

[0005] 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.

[0006] This application is achieved through the following technical solutions:

[0007] In a first aspect, an embodiment of the present application provides a battery cell, which includes a shell, the shell including a first wall and a second wall, the first wall and the second wall are welded to form a first welding zone, the first wall includes a first zone and a second zone arranged along a first direction, the first zone is arranged adjacent to the first welding zone, the thickness of the first zone is greater than the thickness of the second zone, and the first direction is parallel to the thickness direction of the second wall.

[0008] According to the battery cell of the embodiment of the present application, the first wall and the second wall are welded to form a first welding zone, and the first zone adjacent to the first welding zone is thickened so that the thickness of the first zone is greater than the thickness of the second zone, thereby reducing the risk of fatigue cracking in the first zone and improving the reliability of the battery cell.

[0009] According to some embodiments of the present application, along the first direction, the size of the first area is H, satisfying 0<H≤5mm.

[0010] In the above solution, the size of the first area in the first direction satisfies the above range, and the first area has a certain range in the first direction, which can reduce the risk of cracking in the area of ​​the first wall close to the first welding area.

[0011] According to some embodiments of the present application, the thickness of the first region is t, the thickness of the second region is a, and a<t≤4a is satisfied.

[0012] In the above solution, the thickness of the first region and the thickness of the second region satisfy the above relationship, the first region has higher strength, and the first region occupies a smaller assembly space, so that the battery cell has a higher energy density.

[0013] According to some embodiments of the present application, a+0.1 mm≤t≤3a.

[0014] In the above solution, compared with a<t≤4a, when a+0.1mm≤t≤3a, the first area occupies a smaller assembly space and has higher strength.

[0015] According to some embodiments of the present application, one of the following conditions is met: along the thickness direction of the first wall, the second zone has a first surface facing the interior of the battery cell, and part of the first zone protrudes from the first surface; along the thickness direction of the first wall, the second zone has a second surface facing away from the interior of the battery cell, and part of the first zone protrudes from the second surface; along the thickness direction of the first wall, the second zone has a first surface facing the interior of the battery cell and a second surface facing away from the interior of the battery cell, part of the first zone protrudes from the first surface, and part of the first zone protrudes from the second surface.

[0016] In the above solution, when the first region partially protrudes from the first surface, the first region protrudes toward the interior of the battery cell relative to the second region. This reduces the space occupied by the first region on the side of the first wall facing away from the interior of the battery cell, while the first region has relatively high strength. When the first region partially protrudes from the second surface, the first region protrudes away from the interior of the battery cell relative to the second region. This reduces the space occupied by the first region on the side of the first wall facing the interior of the battery cell, while the first region has relatively high strength. When both the first region and the second region protrude from the first surface, the first region has relatively high strength and occupies relatively small space on both the side of the first wall facing the interior of the battery cell and the side facing away from the interior of the battery cell, respectively.

[0017] According to some embodiments of the present application, the first zone includes a thickening section and a transition section arranged along a first direction, the thickening section is connected to the second zone through the transition section, the thickness of the thickening section is greater than the thickness of the second zone, and the thickness of the transition section gradually decreases from the thickening section to the second zone.

[0018] In the above solution, the thickness of the transition section gradually decreases from the thickened section to the second zone to facilitate processing and manufacturing.

[0019] According to some embodiments of the present application, the first wall also includes a third zone. Along the first direction, the third zone, the first zone and the second zone are distributed in sequence. The second wall is connected to the third zone to form a first welding zone. The maximum thickness of the third zone is less than the maximum thickness of the first zone.

[0020] In the above scheme, the third zone, the first zone and the second zone are distributed in sequence along the first direction, the third zone is connected to the second wall, and the maximum thickness of the first zone is greater than the maximum thickness of the third zone, so that the first zone has higher strength to reduce the risk of fatigue cracking of the first wall, so that the battery cell has higher reliability.

[0021] According to some embodiments of the present application, the housing includes a shell and an end cover, the shell has an opening, the end cover closes the opening, one of the first wall and the second wall is the end cover, and the other is at least one wall portion of the shell.

[0022] In the above solution, when the first wall is an end cap and the second wall is at least one wall portion of the housing, the end cap can be thinner, satisfying the requirement for thinner wall thickness of the housing, thereby enabling the battery cell to have a higher gravimetric energy density. When the first wall is at least one wall portion of the housing and the second wall is an end cap, the housing is thinner than the end cap, and the thickening of the first area of ​​the first wall can reduce the risk of fatigue cracking of the first wall.

[0023] According to some embodiments of the present application, the shell includes two first side walls arranged opposite to each other along a second direction and two second side walls arranged opposite to each other along a third direction, the second direction, the third direction and the first direction are perpendicular to each other, the two first side walls and the two second side walls form a cavity with an opening, and the end cover closes the opening; the second wall is the end cover, and the first wall is the first side wall.

[0024] In the above solution, the second wall is the end cover, the first wall is the first side wall, the first side wall is connected to the end cover, and a thickened area is provided on the first side wall, which can reduce the risk of fatigue cracking of the first side wall and make the battery cell have higher reliability.

[0025] According to some embodiments of the present application, the second side wall and the end cover are welded to form a second fusion zone, the second side wall includes a third zone and a fourth zone arranged along the first direction, the third zone is arranged adjacent to the second fusion zone, and the maximum thickness of the third zone is greater than the maximum thickness of the fourth zone.

[0026] In the above solution, the thickening treatment of the second area of ​​the second side wall adjacent to the second fusion zone can reduce the risk of fatigue cracking of the second side wall.

[0027] According to some embodiments of the present application, the shell also includes a bottom wall, two first side walls and two second side walls are arranged around the bottom wall, the two first side walls and the two second side walls are connected to the bottom wall, the two first side walls and the two second side walls are integrally formed with the bottom wall, and the end cover is arranged opposite to the bottom wall.

[0028] In the above solution, the shell is integrally formed, which is convenient for processing and manufacturing.

[0029] According to some embodiments of the present application, the shell also includes a bottom wall, two first side walls and two second side walls are arranged around the bottom wall, the two first side walls and the two second side walls are all connected to the bottom wall, the end cover is arranged opposite to the bottom wall, and the area of ​​the outer surface of the first side wall is greater than the area of ​​the outer surface of the second side wall and greater than the area of ​​the outer surface of the bottom wall.

[0030] In the above solution, the first side wall can be the large surface of the battery cell. During the charge and discharge cycle of the battery cell, the large surface is subjected to a large force. Thickening the opening of the first side wall can reduce the risk of fatigue cracking of the large surface and improve the reliability of the battery cell.

[0031] According to some embodiments of the present application, openings are respectively provided at both ends of the shell, and there are two end covers, each of which closes the corresponding opening.

[0032] In the above solution, openings are respectively provided at both ends of the shell, and both openings are thickened to reduce the risk of fatigue cracking of the shell.

[0033] According to some embodiments of the present application, the maximum thickness of the first wall is smaller than the maximum thickness of the second wall.

[0034] In the above solution, the maximum thickness of the first wall is less than the maximum thickness of the second wall, and the thickening treatment of the first area of ​​the first wall can reduce the risk of fatigue cracking of the first wall.

[0035] In a second aspect, an embodiment of the present application provides a battery, which includes a battery cell provided in any of the above embodiments.

[0036] According to some embodiments of the present application, the housing includes a shell and an end cover, the shell has an opening, the end cover closes the opening, the second wall is the end cover, the first wall is a wall portion of the shell, the number of battery cells is multiple, and the multiple battery cells are stacked along a second direction, the second direction is perpendicular to the first direction, and the battery also includes an end plate, along the second direction, the end plate is arranged at the end of the multiple battery cells, along the direction of the second zone pointing to the first zone, at least part of the first zone exceeds the end plate.

[0037] In the above solution, the end plates are arranged at the ends of the plurality of battery cells in the second direction, and the end plates have a large connection area with the shells of adjacent battery cells to form a constraint on the shells and reduce the risk of fatigue cracking of the shells.

[0038] According to some embodiments of the present application, the end plate is disposed facing the first wall.

[0039] In the above solution, the end plate is arranged facing the first wall, and has a large contact area with the second area. During the battery cell charge and discharge cycle, the end plate can constrain the first wall to reduce the risk of fatigue cracking of the first wall.

[0040] In a third aspect, an embodiment of the present application provides an electrical device, which includes a battery cell or a battery as provided in any of the above embodiments.

[0041] In a fourth aspect, an embodiment of the present application provides an energy storage device, which includes a battery cell or a battery as provided in any of the above embodiments.

[0042] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become obvious from the description below, or will be learned through practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] 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 show 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.

[0044] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0045] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0046] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0047] FIG4 is a schematic diagram of a connection state of a first wall and a second wall provided in some embodiments of the present application;

[0048] FIG5 is a schematic diagram of a first region protruding from a first surface provided by some embodiments of the present application;

[0049] FIG6 is a schematic diagram of a first region protruding from a second surface provided by some embodiments of the present application;

[0050] FIG7 is a schematic diagram of a first region protruding from a first surface and a second surface according to some embodiments of the present application;

[0051] FIG8 is a schematic structural diagram of a housing provided in some embodiments of the present application;

[0052] FIG9 is a schematic diagram of a connection state between a second side wall and an end cover provided in some embodiments of the present application;

[0053] FIG10 is a schematic diagram of the assembly of an end plate and a plurality of battery cells provided in some embodiments of the present application;

[0054] FIG11 is a schematic diagram of the assembly of the end plate and the battery cell provided in an embodiment of the present application;

[0055] FIG12 is a partial enlarged view of point A in FIG11 .

[0056] In the drawings, the drawings are not drawn to scale.

[0057] Marking instructions: 100 - battery; 10 - housing; 11 - first sub-housing; 12 - second sub-housing; 20 - battery cell; 21 - housing; 211 - housing; 211a - first side wall; 211b - second side wall; 211c - bottom wall; 212 - end cover; 213 - first wall; 2131 - first area; 2131a - thickened section; 2131b - transition section; 2132 - second area; 2132a - first surface; 213 2b-second surface; 2133-fifth zone; 214-second wall; 215-first welding zone; 216-second welding zone; 217-third zone; 218-fourth zone; 21a-electrode terminal; 22-electrode assembly; 23-adapter; 30-end plate; 200-controller; 300-motor; 1000-vehicle; F-dividing line; P-thickness direction of the first wall; X-first direction; Y-second direction; Z-third direction. DETAILED DESCRIPTION

[0058] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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.

[0065] 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.

[0066] 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.

[0067] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.).

[0074] 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.

[0075] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] In some embodiments, the electrode assembly is a laminate structure.

[0084] 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, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0085] 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.

[0086] 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.

[0087] In some embodiments, the housing is provided with an explosion-proof valve for releasing the internal pressure of the battery cell.

[0088] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include square-shell, blade-shaped, and polygonal batteries. Polygonal batteries may be, for example, hexagonal batteries.

[0089] 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.

[0090] In some embodiments, a battery cell includes an outer shell, which includes a housing and an end cap. The housing has an opening, and the end cap seals the opening. To achieve the connection between the end cap and the housing, the end cap is typically welded to the housing. However, after the end cap and the housing are welded to form a weld mark, the area of ​​the end cap and the housing adjacent to the weld mark forms a heat-affected zone due to the high welding temperature, and the strength of the portion in the heat-affected zone is reduced. During the charge and discharge cycle of the battery cell, the components within the battery cell participate in electrochemical reactions, causing the housing to expand and contract, resulting in fatigue cracking in the heat-affected zone, which may lead to electrolyte leakage and even the risk of fire and explosion, resulting in low reliability of the battery cell.

[0091] In view of this, an embodiment of the present application provides a technical solution, in which a battery cell includes a shell, the shell includes a first wall and a second wall, the first wall and the second wall are welded to form a first welding zone, the first welding zone is a weld mark, the first wall includes a first zone and a second zone arranged along a first direction, the first direction is parallel to the thickness direction of the second wall, the first zone is arranged adjacent to the first welding zone, the thickness of the first zone is greater than the thickness of the second zone, so that the battery cell has higher reliability.

[0092] In such a battery cell, at least part of the first zone can be a heat-affected zone, and the thickness of the first zone is greater than that of the second zone. Thickening the first zone can increase the strength of the first zone to reduce the risk of fatigue cracking in the first zone, thereby improving the reliability of the battery cell.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] Please refer to Figure 2, which is an exploded view 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, which cover each other and together define 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-like 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.

[0100] 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.

[0101] 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.

[0102] Please refer to Figure 3, which is an exploded view 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.

[0103] 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.

[0104] The end cap 212 refers to a component that covers the opening of the shell 211 to isolate the internal environment of the battery cell 20 from the external environment. Without limitation, the shape of the end cap 212 can be adapted to the shape of the shell 211 to match the shell 211. Optionally, the end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 212 is not easily deformed when squeezed or collided, so that the battery cell 20 can have a higher structural strength and the reliability can also be improved. Functional components such as electrode terminals 21a can be provided on the end cap 212. The electrode terminal 21a can be used to electrically connect to the electrode assembly 22 for outputting or inputting electrical energy of the battery cell 20. The material of the end cap 212 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating structure may be provided inside the end cap 212 to isolate the electrical connection components in the housing 211 from the end cap 212 to reduce the risk of short circuits. For example, the insulating structure may be made of plastic, rubber, or the like.

[0105] 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.

[0106] Please refer to Figure 3 and further refer to Figure 4, which is a schematic diagram of the connection state of the first wall and the second wall provided in some embodiments of the present application. The embodiment of the present application provides a battery cell 20, which includes a shell 21. The shell 21 includes a first wall 213 and a second wall 214. The first wall 213 and the second wall 214 are welded to form a first welding area 215. The first wall 213 includes a first area 2131 and a second area 2132 arranged along a first direction X. The first area 2131 is arranged adjacent to the first welding area 215. The thickness of the first area 2131 is greater than the thickness of the second area 2132. The first direction X is parallel to the thickness direction of the second wall 214.

[0107] In FIG4 , the direction indicated by the letter X may be a first direction. The first direction X is parallel to the thickness direction of the second wall 214. For example, when the first wall 213 is the end cap 212 and the second wall 214 is a wall of the housing 211 connected to the end cap 212, the first area 2131 and the second area 2132 are sequentially distributed in the thickness direction of the second wall 214. Alternatively, when the first wall 213 is a wall of the housing 211 connected to the end cap 212 and the second wall 214 is the end cap 212, the first area 2131 and the second area 2132 are sequentially distributed in the thickness direction of the end cap 212.

[0108] First weld zone 215 is formed after welding first wall 213 and second wall 214. First weld zone 215 may be a weld mark. After first wall 213 and second wall 214 are welded to form first weld zone 215, the area immediately adjacent to first weld zone 215 forms a heat-affected zone. At least a portion of first zone 2131 may be the heat-affected zone.

[0109] The first zone 2131 is arranged adjacent to the first welding zone 215, which means that the first zone 2131 and the first welding zone 215 are distributed in sequence along the first direction X. For example, the dotted line in Figure 4 is the dividing line F between the first welding zone 215 and the first zone 2131, and the edge of one end of the first welding zone 215 in the first direction X contacts the edge of the end of the first zone 2131 in the first direction X away from the second zone 2132.

[0110] In some embodiments, the first wall 213 further includes a fifth zone 2133 . Along the first direction X, the fifth zone 2133 , the first zone 2131 , and the second zone 2132 are distributed in sequence. The second wall 214 is connected to the fifth zone 2133 to form a first welding zone 215 . The maximum thickness of the fifth zone 2133 is less than the maximum thickness of the first zone 2131 .

[0111] In Figure 4 , the area above the dividing line F is the fifth region 2133 and the first welded area 215, while the area below the dividing line F is the first region 2131. The fifth region 2133, the first region 2131, and the second region 2132 are sequentially arranged along the first direction X. The fifth region 2133 is connected to the second wall 214, and the maximum thickness of the first region 2131 is greater than the maximum thickness of the fifth region 2133. This ensures that the first region 2131 has greater strength, reduces the risk of fatigue cracking of the first wall 213, and enhances the reliability of the battery cell 20.

[0112] The second area 2132 may be disposed adjacent to the first area 2131 in the first direction X, or the second area 2132 may be disposed spaced apart from the first area 2131 in the first direction X.

[0113] The thickness of the first region 2131 is greater than that of the second region 2132 . The first region 2131 is thickened relative to the second region 2132 to improve the strength of the first region 2131 .

[0114] According to the battery cell 20 of the embodiment of the present application, the first wall 213 and the second wall 214 are welded to form a first welding zone 215, and the first zone 2131 adjacent to the first welding zone 215 is thickened so that the thickness of the first zone 2131 is greater than the thickness of the second zone 2132, thereby reducing the risk of fatigue cracking of the first zone 2131 and improving the reliability of the battery cell 20.

[0115] Referring to FIG. 4 , according to some embodiments of the present application, along the first direction X, the size of the first region 2131 is H, satisfying 0<H≤5 mm.

[0116] H may be the size of the first zone 2131 in the first direction X. Optionally, H may be, but is not limited to, 0.1 mm, 0.3 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc.

[0117] Optionally, 1mm≤H≤4mm.

[0118] In the above solution, the size of the first area 2131 in the first direction X satisfies the above range. The first area 2131 has a certain range in the first direction X, which can reduce the risk of cracking in the area of ​​the first wall 213 close to the first welding area 215.

[0119] Referring to FIG. 4 , according to some embodiments of the present application, the thickness of the first region 2131 is t, and the thickness of the second region 2132 is a, satisfying a<t≤4a.

[0120] In the figure, the direction indicated by letter P may be the thickness direction of the first wall 213. The thickness direction of the first area 2131 is parallel to the thickness direction P of the first wall, and the thickness direction of the second area 2132 is parallel to the thickness direction P of the first wall.

[0121] Optionally, the thickness t of the first region 2131 may be, but is not limited to, a, 1.2a, 1.4a, 1.6a, 1.8a, 2a, 2.2a, 2.4a, 2.6a, 2.8a, 3a, 3.2a, 3.4a, 3.6a, 3.8a, 4a, etc.

[0122] In the above solution, the thickness of the first region 2131 and the thickness of the second region 2132 satisfy the above relationship, the first region 2131 has higher strength, and the first region 2131 occupies less assembly space, so that the battery cell 20 has higher energy density.

[0123] According to some embodiments of the present application, a+0.1 mm≤t≤3a.

[0124] In some embodiments, a>0.2 mm, for example, 0.4 mm≤a≤2 mm.

[0125] Optionally, a may be, but is not limited to, 0.4 mm, 0.5 mm, 0.6 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, etc. a may be any value between 0.4 mm and 2 mm.

[0126] Alternatively, t may be, but is not limited to, a+0.1 mm, 2a, 2.1 a, 2.2a, 2.3a, 2.4a, 2.5a, 2.6a, 2.7a, 2.8a, 2.9a, 3a, etc.

[0127] In the above solution, compared with a<t≤4a, when a+0.1mm≤t≤3a, the first region 2131 occupies a smaller assembly space and has higher strength.

[0128] Please refer to Figures 5 to 7. Figure 5 is a schematic diagram of a first region protruding from a first surface according to some embodiments of the present application. Figure 6 is a schematic diagram of a first region protruding from a second surface according to some embodiments of the present application. Figure 7 is a schematic diagram of a first region protruding from both a first surface and a second surface according to some embodiments of the present application. According to some embodiments of the present application, one of the following conditions is satisfied: along the thickness direction P of the first wall, the second region 2132 has a first surface 2132a facing the interior of the battery cell 20, and a portion of the first region 2131 protrudes from the first surface 2132a; along the thickness direction P of the first wall, the second region 2132 has a second surface 2132b facing away from the interior of the battery cell 20, and a portion of the first region 2131 protrudes from the second surface 2132b; along the thickness direction P of the first wall, the second region 2132 has a first surface 2132a facing the interior of the battery cell 20 and a second surface 2132b facing away from the interior of the battery cell 20, and a portion of the first region 2131 protrudes from the first surface 2132a, and a portion of the first region 2131 protrudes from the second surface 2132b.

[0129] The first surface 2132 a and the second surface 2132 b may be two surfaces of the second region 2132 that are opposite to each other in the thickness direction P of the first wall.

[0130] When part of the first zone 2131 protrudes from the first surface 2132a, the first zone 2131 protrudes toward the interior of the battery cell 20 relative to the second zone 2132. When the first zone 2131 has higher strength, the space occupied by the first zone 2131 on the side of the first wall 213 facing away from the interior of the battery cell 20 is reduced.

[0131] When a portion of the first zone 2131 protrudes from the second surface 2132b, the first zone 2131 protrudes in a direction away from the interior of the battery cell 20 relative to the second zone 2132. While the first zone 2131 has higher strength, the space occupied by the first zone 2131 on the side of the first wall 213 facing the interior of the battery cell 20 is reduced.

[0132] When part of the first zone 2131 protrudes from the first surface 2132a and part of the first zone 2131 protrudes from the second surface 2132b, the first zone 2131 has higher strength and occupies smaller space on the side of the first wall 213 facing the interior of the battery cell 20 and the side away from the interior of the battery cell 20, respectively.

[0133] Please refer to Figure 5. According to some embodiments of the present application, the first zone 2131 includes a thickening section 2131a and a transition section 2131b arranged along the first direction X. The thickening section 2131a is connected to the second zone 2132 through the transition section 2131b. The thickness of the thickening section 2131a is greater than the thickness of the second zone 2132, and the thickness of the transition section 2131b gradually decreases from the thickening section 2131a to the second zone 2132.

[0134] The thickened section 2131a and the transition section 2131b are arranged along the first direction X. The thickened section 2131a is connected to the second area 2132 through the transition section 2131b, so that the thickened section 2131a, the transition section 2131b and the second area 2132 are distributed in sequence along the first direction X.

[0135] The thickened section 2131a can be a uniform thickness section or a variable thickness section. For example, when the thickened section 2131a is a uniform thickness section, the thickness of any region of the thickened section 2131a along the first direction X is equal, facilitating manufacturing. When the thickened section 2131a is a variable thickness section, the thickness of different regions of the thickened section 2131a varies.

[0136] Optionally, the thickened section 2131a is a section of equal thickness.

[0137] The thickness of the thickened section 2131 a is greater than the thickness of the second region 2132 , and the thickness of any region of the thickened section 2131 a is greater than the thickness of the second region 2132 .

[0138] In the above solution, the transition section 2131b is a transition area between the thickened section 2131a and the second area 2132, and the thickness of the transition section 2131b gradually decreases from the thickened section 2131a to the second area 2132 to facilitate processing and manufacturing.

[0139] Please refer to Figure 3 and further to Figure 8, which is a schematic diagram of the structure of a housing provided in some embodiments of the present application. According to some embodiments of the present application, the housing 21 includes a shell 211 and an end cap 212. The shell 211 has an opening, and the end cap 212 closes the opening. One of the first wall 213 and the second wall 214 is the end cap 212, and the other is at least one wall portion of the shell 211.

[0140] The housing 211 is used to carry the electrode assembly and the electrolyte. The end cap 212 closes the opening and is connected to the housing 211 to form a closed space.

[0141] The first wall 213 may be the end cover 212 , and the second wall 214 may be at least one wall portion of the shell 211 ; or, the first wall 213 may be at least one wall portion of the shell 211 , and the second wall 214 may be the end cover 212 .

[0142] In the above solution, when the first wall 213 is the end cap 212 and the second wall 214 is at least one wall portion of the housing 211, the end cap 212 can be thinner, satisfying the requirement for thinner wall thickness of the outer shell 21, thereby enabling the battery cell 20 to have a higher gravimetric energy density. When the first wall 213 is at least one wall portion of the housing 211 and the second wall 214 is the end cap 212, the housing 211 is thinner than the end cap 212. The thickened first region 2131 of the first wall 213 can reduce the risk of fatigue cracking of the first wall 213.

[0143] Please refer to Figure 8. According to some embodiments of the present application, the shell 211 includes two first side walls 211a arranged opposite to each other along the second direction Y and two second side walls 211b arranged opposite to each other along the third direction Z. The second direction Y, the third direction Z and the first direction X are perpendicular to each other. The two first side walls 211a and the two second side walls 211b form a cavity with an opening, and the end cover 212 closes the opening; the second wall 214 is the end cover 212, and the first wall 213 is the first side wall 211a.

[0144] The two first side walls 211a are arranged opposite to each other along the second direction Y, and the two first side walls 211a are arranged in parallel; the two second side walls 211b are arranged opposite to each other along the third direction Z, and the two second side walls 211b are arranged in parallel; the two ends of each first side wall 211a are respectively connected to the two second side walls 211b, and the two first side walls 211a and the two second side walls 211b form a cavity with an opening, so that the shell 211 is in the shape of a rectangular parallelepiped.

[0145] In the above solution, the second wall 214 is the end cover 212, the first wall 213 is the first side wall 211a, the first side wall 211a is connected to the end cover 212, and a thickened area is provided on the first side wall 211a, which can reduce the risk of fatigue cracking of the first side wall 211a, so that the battery cell 20 has higher reliability.

[0146] According to some embodiments of the present application, the area of ​​the outer surface of the first sidewall 211 a is greater than the area of ​​the outer surface of the second sidewall 211 b .

[0147] The first side wall 211a can be the large surface of the battery cell 20. During the charge and discharge cycle of the battery cell 20, the first side wall 211a is subjected to a large force. The first wall 213 is the first side wall 211a. The thickening treatment of the first area 2131 can improve the strength of the first side wall 211a and reduce the risk of fatigue cracking of the first side wall 211a.

[0148] Please refer to Figure 9, which is a schematic diagram illustrating the connection between the second sidewall and the end cap according to some embodiments of the present application. According to some embodiments of the present application, the second sidewall 211b and the end cap 212 are welded to form a second fusion zone 216. The second sidewall 211b includes a third zone 217 and a fourth zone 218 arranged along the first direction X. The third zone 217 is located adjacent to the second fusion zone 216, and the maximum thickness of the third zone 217 is greater than the maximum thickness of the fourth zone 218.

[0149] The thickness direction of the second sidewall 211 b may be parallel to the third direction Z. The thickness direction of the third region 217 and the thickness direction of the fourth region 218 are both parallel to the third direction Z.

[0150] Second weld zone 216 is formed after welding second sidewall 211b and end cap 212. Second weld zone 216 may be a weld mark. After second sidewall 211b and end cap 212 are welded to form second weld zone 216, the area immediately adjacent to second weld zone 216 forms a heat-affected zone. At least a portion of third zone 217 may be the heat-affected zone.

[0151] The third zone 217 is arranged adjacent to the second welding zone 216, which means that the third zone 217 and the second welding zone 216 are distributed in sequence along the first direction X, and the edge of one end of the second welding zone 216 in the first direction X contacts the edge of the third zone 217 in the first direction X away from the fourth zone 218.

[0152] The fourth area 218 may be disposed adjacent to the third area 217 in the first direction X, or the fourth area 218 may be disposed spaced apart from the third area 217 in the first direction X.

[0153] The thickness of the third region 217 is greater than that of the fourth region 218 . The third region 217 is thickened relative to the fourth region 218 to improve the strength of the third region 217 .

[0154] In the above solution, the second area 2132 of the second side wall 211 b adjacent to the second welding area 216 is thickened, which can reduce the risk of fatigue cracking of the second side wall 211 b.

[0155] Please refer to Figure 8. According to some embodiments of the present application, the shell 211 also includes a bottom wall 211c, two first side walls 211a and two second side walls 211b are arranged around the bottom wall 211c, the two first side walls 211a and the two second side walls 211b are both connected to the bottom wall 211c, the two first side walls 211a and the two second side walls 211b are integrally formed with the bottom wall 211c, and the end cover 212 is arranged opposite to the bottom wall 211c.

[0156] The bottom wall 211 c and the end cover 212 are disposed opposite to each other along the thickness direction of the end cover 212 . The thickness direction of the end cover 212 , the second direction Y, and the third direction Z are perpendicular to each other.

[0157] The two first side walls 211 a and the two second side walls 211 b are integrally formed with the bottom wall 211 c . The housing 211 may be stamped from a single plate, or the housing 211 may be roll-formed from a single plate.

[0158] In the above solution, the housing 211 is integrally formed, which is convenient for processing and manufacturing.

[0159] According to some embodiments of the present application, the shell 211 also includes a bottom wall 211c, two first side walls 211a and two second side walls 211b are arranged around the bottom wall 211c, the two first side walls 211a and the two second side walls 211b are all connected to the bottom wall 211c, the end cover 212 is arranged opposite to the bottom wall 211c, and the area of ​​the outer surface of the first side wall 211a is greater than the area of ​​the outer surface of the second side wall 211b and greater than the area of ​​the outer surface of the bottom wall 211c.

[0160] In the above scheme, the first side wall 211a can be the large surface of the battery cell 20. During the charge and discharge cycle of the battery cell 20, the large surface is subjected to a large force. The opening of the first side wall 211a is thickened to reduce the risk of fatigue cracking of the large surface and improve the reliability of the battery cell 20.

[0161] According to some embodiments of the present application, openings are respectively provided at both ends of the shell 211 , and there are two end covers 212 , each of which closes the corresponding opening.

[0162] In the above solution, openings are respectively provided at both ends of the shell 211 , and both openings are thickened to reduce the risk of fatigue cracking of the shell 211 .

[0163] According to some embodiments of the present application, the maximum thickness of the first wall 213 is smaller than the maximum thickness of the second wall 214 .

[0164] The first side wall 211 a is a first wall 213 , and the end cover 212 is a second wall 214 . The maximum thickness of the first side wall 211 a is smaller than the maximum thickness of the end cover 212 , and the end cover 212 has higher strength.

[0165] In the above solution, the maximum thickness of the first wall 213 is less than the maximum thickness of the second wall 214 , and the thickening treatment of the first area 2131 of the first wall 213 can reduce the risk of fatigue cracking of the first wall 213 .

[0166] According to some embodiments of the present application, an embodiment of the present application provides a battery 100, which includes a battery cell 20 provided in any of the above embodiments.

[0167] Please refer to Figure 10, which is a schematic diagram of the assembly of the end plate and multiple battery cells provided in some embodiments of the present application. According to some embodiments of the present application, the housing 21 includes a shell 211 and an end cover 212, the shell 211 has an opening, and the end cover 212 closes the opening. The second wall 214 is the end cover 212, and the first wall 213 is a wall portion of the shell 211. There are multiple battery cells 20, and the multiple battery cells 20 are stacked along the second direction Y, and the second direction Y is perpendicular to the first direction X. The battery 100 also includes an end plate 30, which is arranged at the end of the multiple battery cells 20 along the second direction Y, along the direction of the second area 2132 pointing to the first area 2131, and at least part of the first area 2131 exceeds the end plate 30.

[0168] Multiple battery cells 20 are stacked along the second direction Y. Along the second direction Y, the end plate 30 is arranged at the end of the multiple battery cells 20. The end plate 30 is connected to the battery cell 20 at the end of the multiple battery cells 20 in the second direction Y. The end plate 30 can limit the battery cell 20 at the end and restrain the deformation of the battery cell 20.

[0169] In the above solution, the end plate 30 is arranged at the end of multiple battery cells 20 in the second direction Y. 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 and reduce the risk of fatigue cracking of the shell 211.

[0170] 11 and 12 , FIG11 is a schematic diagram of the assembly of the end plate 30 and the battery cell according to an embodiment of the present application, and FIG12 is a partial enlarged view of point A in FIG11 . According to some embodiments of the present application, the end plate 30 is disposed facing the first wall 213 .

[0171] In the above solution, the end plate 30 is arranged facing the first wall 213, and the end plate 30 has a large contact area with the second area 2132. During the charge and discharge cycle of the battery cell 20, the end plate 30 can constrain the first wall 213 to reduce the risk of fatigue cracking of the first wall 213.

[0172] According to some embodiments of the present application, an electric device is provided, which includes a battery cell 20 or a battery 100 provided in any one of the above embodiments.

[0173] 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.

[0174] According to some embodiments of the present application, an energy storage device is provided. The energy storage device includes a battery cell 20 or a battery 100 as provided in any one of the above embodiments.

[0175] According to some embodiments of the present application, referring to Figures 4 to 9 , a battery cell 20 is provided. The battery cell 20 is in the form of a rectangular parallelepiped. The battery cell 20 includes a housing 21, an electrode assembly, and electrode terminals. The electrode assembly is disposed within the housing 21. The housing 21 includes a shell 211 and an end cap 212. The electrode terminal 21a is disposed in the end cap 212. The electrode terminal 21a is connected to the tab of the electrode assembly 22 via an adapter 23. The housing 211 includes two first side walls 211a arranged opposite each other along a second direction Y, two second side walls 211b arranged opposite each other along a third direction Z, and a bottom wall 211c. The two first side walls 211a and the two second side walls 211b form a cavity with an opening. The end cap 212 closes the opening and is disposed opposite the bottom wall 211c. The housing 21 includes a first wall 213 and a second wall 214. The first wall 213 is the first side wall 211a, and the second wall 214 is the end cap 212. The first wall 213 and the second wall 214 are welded to form a first welding zone 215. The first wall 213 includes a first zone 2131 and a second zone 2132 arranged along a first direction X. The first zone 2131 is arranged adjacent to the first welding zone 215. The thickness of the first zone 2131 is greater than that of the second zone 2132. The first direction X is parallel to the thickness direction of the second wall 214.

[0176] According to the battery cell 20 of the embodiment of the present application, the first area 2131 of the first side wall 211a close to the first welding area 215 is thickened, so that the first area 2131 has higher strength, reducing the risk of fatigue cracking of the first side wall 211a, and making the battery cell 20 have higher reliability.

[0177] 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, comprising: a housing including a first wall and a second wall, the first wall and the second wall being welded to form a first welding zone, the first wall including a first region and a second region arranged along a first direction, the first region being disposed adjacent to the first welding zone, the thickness of the first region being greater than the thickness of the second region, and the first direction being parallel to the thickness direction of the second wall.

2. The battery cell according to claim 1, wherein along the first direction, the size of the first region is H, satisfying 0 < H ≤ 5 mm.

3. The battery cell according to claim 1 or 2, wherein the thickness of the first region is t, and the thickness of the second region is a, satisfying a < t ≤ 4a.

4. The battery cell according to claim 3, wherein a + 0.1 mm ≤ t ≤ 3a.

5. The battery cell according to any one of claims 1-4, wherein one of the following conditions is satisfied: along the thickness direction of the first wall, the second region has a first surface facing the interior of the battery cell, and a part of the first region protrudes from the first surface; along the thickness direction of the first wall, the second region has a second surface facing away from the interior of the battery cell, and a part of the first region protrudes from the second surface; along the thickness direction of the first wall, the second region has a first surface facing the interior of the battery cell and a second surface facing away from the interior of the battery cell, a part of the first region protrudes from the first surface, and a part of the first region protrudes from the second surface.

6. The battery cell according to any one of claims 1-5, wherein the first region includes a thickened section and a transition section arranged along the first direction, the thickened section is connected to the second region through the transition section, the thickness of the thickened section is greater than the thickness of the second region, and the thickness of the transition section gradually decreases from the thickened section to the second region.

7. The battery cell according to any one of claims 1-6, wherein the first wall further includes a third region, along the first direction, the third region, the first region and the second region are arranged in sequence, the second wall is connected to the third region to form the first welding zone, and the maximum thickness of the third region is less than the maximum thickness of the first region.

8. The battery cell according to any one of claims 1-7, wherein the housing includes a housing body and an end cap, the housing body has an opening, the end cap closes the opening, and one of the first wall and the second wall is the end cap, and the other is at least one wall portion of the housing body.

9. The battery cell according to claim 8, wherein the housing body includes two first side walls oppositely arranged along a second direction and two second side walls oppositely arranged along a third direction, the second direction, the third direction and the first direction are perpendicular to each other in pairs, the two first side walls and the two second side walls enclose a cavity with an opening, and the end cap closes the opening; the second wall is the end cap, and the first wall is the first side wall.

10. The battery cell according to claim 9, wherein The second side wall and the end cover are welded to form a second welding zone. The second side wall includes a third zone and a fourth zone arranged along the first direction. The third zone is adjacent to the second welding zone, and the maximum thickness of the third zone is greater than the maximum thickness of the fourth zone.

11. The battery cell according to claim 9 or 10, wherein, the housing further includes a bottom wall. The two first side walls and the two second side walls surround the bottom wall. The two first side walls and the two second side walls are both connected to the bottom wall. The two first side walls and the two second side walls are integrally formed with the bottom wall. The end cover is disposed opposite to the bottom wall.

12. The battery cell according to any one of claims 9-11, wherein, the housing further includes a bottom wall. The two first side walls and the two second side walls surround the bottom wall. The two first side walls and the two second side walls are both connected to the bottom wall. The end cover is disposed opposite to the bottom wall. The area of the outer surface of the first side wall is greater than the area of the outer surface of the second side wall and greater than the area of the outer surface of the bottom wall.

13. The battery cell according to any one of claims 9-12, wherein, openings are respectively provided at both ends of the housing. The number of end covers is two, and each end cover closes the corresponding opening.

14. The battery cell according to any one of claims 9-13, wherein, the maximum thickness of the first wall is less than the maximum thickness of the second wall.

15. A battery, comprising the battery cell according to any one of claims 1-14.

16. The battery according to claim 15, wherein, the outer shell includes a housing and an end cover. The housing has an opening. The end cover closes the opening. The second wall is the end cover. The first wall is a wall portion of the housing. The number of battery cells is multiple, and the multiple battery cells are stacked along a second direction perpendicular to the first direction. The battery further includes an end plate. Along the second direction, the end plate is disposed at the end of the multiple battery cells. Along the direction from the second zone to the first zone, at least a part of the first zone exceeds the end plate.

17. The battery according to claim 16, wherein, the end plate faces the first wall.

18. An electrical device, comprising the battery cell according to any one of claims 1-14 or the battery according to any one of claims 15-17. The battery cell or the battery is used to provide electrical energy.

19. An energy storage device, comprising the battery cell according to any one of claims 1-14 or the battery according to any one of claims 15-17.

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