Battery cell, battery, and electrical device

Abstract

A battery cell (20), a battery (100), and an electrical device. The battery cell (20) comprises a casing (21) and a first sealing member (23). The casing (21) comprises a first wall (213), and the first wall (213) is provided with a liquid injection hole (2130); and the first sealing member (23) is configured to seal the liquid injection hole (2130), the first sealing member (23) and the first wall (213) are welded and form a connecting portion (230), the connecting portion (230) is provided around the liquid injection hole (2130), and the connecting portion (230) is exposed to the surface of the first sealing member (23) facing away from the first wall (213). The solution can improve the reliability of the battery (100).

Description

Battery cells, batteries and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application CN202322980687.7, entitled “Battery Cell, Battery and Electrical Equipment”, filed on November 03, 2023, 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, and an electrical 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, and an electrical device, which can improve the reliability of the battery.

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

[0009] In a first aspect, embodiments of the present application provide a battery cell comprising a housing and a first sealing member. The housing comprises a first wall having a liquid injection hole; the first sealing member is configured to seal the liquid injection hole and is welded to the first wall to form a connecting portion. The connecting portion is disposed around the liquid injection hole and is exposed on a surface of the first sealing member facing away from the first wall.

[0010] According to the battery cell of the embodiment of the present application, the first seal is welded to the first wall to form a connecting portion, which can be a weld mark, and the connecting portion is exposed on the surface of the first seal facing away from the first wall, so that the first seal and the first wall can be connected and fixed by penetration welding, which can enable the first seal and the first wall to have a larger sealing area (such as setting a wider connecting portion, or setting multiple connecting portions surrounding the injection hole) to improve the airtightness after the first seal is connected to the first wall, thereby improving the reliability of the battery cell.

[0011] According to some embodiments of the present application, the connecting portion includes a first portion and a second portion sequentially distributed along the thickness direction of the first wall, the first portion is located at the first sealing member, and the second portion is located at the first wall.

[0012] In the above solution, the first portion is located on the first sealing member, and the second portion is located on the first wall, so that the first sealing member is firmly connected to the first wall.

[0013] According to some embodiments of the present application, along the thickness direction of the first wall, there is a gap between the orthographic projection of the connecting portion and the edge of the first sealing member.

[0014] In the above solution, there is a gap between the orthographic projection of the connection portion and the edge of the first seal. The first seal can be connected to the first wall by penetration welding to form a connection portion, so that the first seal is firmly connected to the first wall, thereby improving the reliability of the battery cell.

[0015] According to some embodiments of the present application, the thickness of the first wall is H1, and the thickness of the first sealing member is H2, satisfying H2≤H1.

[0016] In the above solution, the thickness H1 of the first wall is greater than or equal to the wall thickness H2 of the first sealant, so that when the first sealant is welded to the first wall, the first wall near the injection hole is not easily welded through, thereby improving the reliability of the battery cell.

[0017] According to some embodiments of the present application, the connecting portion includes a first connecting portion and a second connecting portion, the first connecting portion is arranged around the liquid injection hole, and the second connecting portion is arranged around the first connecting portion.

[0018] In the above solution, the first connection part is arranged around the injection hole, and the second connection part is arranged around the first connection part, which can enhance the connection stability between the first sealing member and the first wall and improve the airtightness after the first sealing member and the first wall are connected.

[0019] According to some embodiments of the present application, the first seal has a fitting surface for fitting with the first wall, the width of the fitting surface in the first direction is L, the first direction intersects with the thickness direction of the first wall, the thickness of the first wall is H1, and 3*H1≤L≤6*H1 is satisfied.

[0020] In the above scheme, the width of the fitting surface in the first direction satisfies the above relationship. On the one hand, the first seal has a larger connection area with the first wall, and multiple connection parts can be set around the injection hole to ensure that the first seal is firmly connected to the first wall. On the other hand, the first seal occupies a smaller size in the first direction, reducing material.

[0021] According to some embodiments of the present application, the first wall includes a first surface facing away from the interior of the battery cell and a second surface facing the interior of the battery cell, the first surface is formed with a groove, the second surface forms a protrusion at a position corresponding to the groove, the injection hole is arranged on the bottom wall of the groove, and the first seal covers the groove.

[0022] In the above scheme, the first surface and the second surface can be two surfaces opposite to each other in the thickness direction of the first wall, a groove is formed on the first surface, and a protrusion is formed on the second surface at a position corresponding to the groove. The thickness of the first wall can be relatively thin, and the groove can be stamped, and the processing and manufacturing difficulty is relatively low; the injection hole is arranged on the bottom wall of the groove, and the first seal blocks the groove to reduce the space occupied by the first seal after assembly with the first wall.

[0023] According to some embodiments of the present application, the battery cell further includes a second sealing member, at least a portion of which is disposed in the liquid injection hole to seal the liquid injection hole.

[0024] In the above solution, at least a portion of the second sealing member is disposed in the liquid injection hole, so as to seal the liquid injection hole and reduce the risk of electrolyte leakage.

[0025] According to some embodiments of the present application, the first wall includes a flange portion, which is arranged on the side of the protrusion facing the interior of the battery cell, the protrusion has a third surface facing away from the second surface, the injection hole passes through the flange portion, and a portion of the outer periphery of the second seal is in contact with the inner surface of the flange portion.

[0026] In the above scheme, the injection hole passes through the flange portion, and the injection hole can be formed by stamping the first wall. The flange portion is arranged on the side of the bulge facing the interior of the battery cell, which can reasonably utilize the internal space of the battery cell; the flange portion can be annular in structure, and the outer peripheral portion of the second seal is fitted with the inner surface of the flange portion, so that the second seal has a larger sealing area with the first wall while blocking the injection hole, which can improve the sealing performance of the connection between the second seal and the first wall and reduce the risk of electrolyte leakage.

[0027] According to some embodiments of the present application, along the thickness direction of the first wall, the dimension of the flange portion protruding from the third surface is H3, and the wall thickness of the first wall is H1, satisfying H1≤H3≤3*H1.

[0028] In the above solution, the size of the flange protruding from the third surface satisfies the above relationship, which, on the one hand, provides a larger connection area between the second seal and the flange, and on the other hand, reduces the difficulty of processing and manufacturing.

[0029] According to some embodiments of the present application, along the thickness direction of the first wall, a dimension of the second sealing member protruding from the third surface is H4, satisfying H3≤H4.

[0030] In the above solution, the size of the second seal protruding from the third surface satisfies the above relationship. On the one hand, the second seal has a larger connection area with the flange portion. On the other hand, the second seal occupies a smaller assembly space, reducing the risk of interference between the second seal and other components.

[0031] According to some embodiments of the present application, the second sealing member includes a body and a flange, the body blocks the liquid injection hole, and the flange is formed on the outer peripheral surface of the body and connected to the bottom wall of the groove.

[0032] In the above solution, the flange is formed on the outer peripheral surface of the body, and the flange can limit the movement of the body toward the inside of the battery cell; at the same time, the flange is connected to the bottom wall of the groove, which can improve the sealing effect between the second seal and the first wall and reduce the risk of electrolyte leakage.

[0033] According to some embodiments of the present application, the first sealing member is provided with a recessed portion, which is recessed toward the groove. Along the thickness direction of the first wall, the orthographic projection of the recessed portion falls within the orthographic projection of the groove sidewall of the groove.

[0034] In the above solution, the provision of the recessed portion can improve the strength of the first seal. At the same time, the recessed portion is recessed toward the interior of the battery cell and is located in the groove, which can reduce space occupation and reduce the risk of interference between the first seal and other components.

[0035] According to some embodiments of the present application, along the thickness direction of the first wall, the orthographic projection of the recessed portion is arranged around the second sealing member.

[0036] In the above solution, the orthographic projection of the recessed portion is arranged around the second sealing member, which can reduce the risk of interference between the recessed portion and the second sealing member.

[0037] According to some embodiments of the present application, along the first direction, the minimum distance between the orthographic projection of the recess along the thickness direction of the first wall and the orthographic projection of the flange along the thickness direction of the first wall is D1, satisfying 0.05mm≤D1≤0.2mm, and the first direction intersects with the thickness direction of the first wall.

[0038] In the above scheme, the minimum distance between the orthographic projection of the recessed portion along the thickness direction of the first wall and the orthographic projection of the flange along the thickness direction of the first wall in the first direction satisfies the above relationship. On the one hand, the risk of interference between the recessed portion and the flange can be reduced. On the other hand, the space occupied by the recessed portion in the first direction can be reduced.

[0039] According to some embodiments of the present application, the second sealing member is spaced apart from the first sealing member along the thickness direction of the first wall.

[0040] In the above solution, the second sealing member is spaced apart from the first sealing member so that the second sealing member does not interfere with the first sealing member, thereby facilitating assembly of the first sealing member and the first wall.

[0041] According to some embodiments of the present application, the second sealing component is a rubber component.

[0042] In the above solution, the rubber member can undergo elastic deformation, and the second sealing member can be interference-fitted with the liquid injection hole, so as to enhance the sealing effect between the second sealing member and the hole wall of the liquid injection hole.

[0043] According to some embodiments of the present application, the thickness of the first wall is H1, satisfying H1≤0.6 mm.

[0044] In the above solution, the thin first wall facilitates the connection of the first seal to the first wall by penetration welding. This allows for a larger connection area between the first seal and the first wall, thereby improving the airtightness of the connection. The thin first wall also reduces the weight of the battery cell, thereby meeting the requirement for lightweight use.

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

[0046] In a third aspect, an embodiment of the present application further provides an electrical device, which includes a battery cell or a battery as provided in any of the above embodiments, and the battery cell or the battery is used to provide electrical energy.

[0047] 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

[0048] 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.

[0049] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0050] FIG2 is an exploded view of a battery provided in some embodiments of the present application;

[0051] FIG3 is an exploded view of a battery cell provided in some embodiments of the present application;

[0052] FIG4 is a schematic diagram of the assembly of a first sealing member and a first wall provided in some embodiments of the present application;

[0053] FIG5 is a cross-sectional view of an assembled state of a first sealing member and a first wall provided in some embodiments of the present application;

[0054] In the drawings, the drawings are not drawn to scale.

[0055] Marking instructions: 100 - battery; 10 - housing; 11 - first sub-housing; 12 - second sub-housing; 20 - battery cell; 21 - housing; 211 - housing; 212 - end cap; 213 - first wall; 213a - first surface; 213b - second surface; 213c - third surface; 2130 - injection hole; 2131 - groove; 2131a - groove bottom wall; 2131b - groove side wall; 2132 - protrusion; 2133 - flange; 22 - electrode assembly; 23 - first seal; 23a - Fourth surface; 23b-fifth surface; 230-connecting part; 230a-first connecting part; 230b-second connecting part; 2301-first part; 2302-second part; 231-fitting surface; 232-recessed part; 233-second protrusion; 234-second recessed part; 24-second sealing member; 241-main body; 242-flange; 25-electrode terminal; 26-adapter; 200-controller; 300-motor; 1000-vehicle; X-first direction; Z-thickness direction of the first wall. DETAILED DESCRIPTION

[0056] 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.

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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).

[0062] 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.

[0063] 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.

[0064] 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.

[0065] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] 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.).

[0072] 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.

[0073] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] In some embodiments, the electrode assembly is a laminate structure.

[0082] 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).

[0083] 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.

[0084] 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.

[0085] In some embodiments, the housing is provided with an explosion-proof valve for releasing the internal pressure of the battery cell.

[0086] As an example, the battery cell can be a cylindrical battery cell, 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, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in the embodiments of the present application.

[0087] 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.

[0088] A battery cell includes a casing with an injection hole for injecting electrolyte into the cell. After injection, the injection hole is typically sealed to reduce the risk of electrolyte leakage. For example, a metal seal is welded to the casing to seal the injection hole. However, the sealing area between the metal seal and the casing is small. In particular, when the casing has thin walls, butt welding can easily penetrate the metal seal or the casing, failing to achieve satisfactory airtightness after welding.

[0089] In view of this, the present application provides a technical solution, in which a battery cell includes a shell and a first seal, the shell includes a first wall, the injection hole is arranged on the first wall, the first seal is welded to the first wall and forms a connecting portion, the connecting portion is arranged around the injection hole, the connecting portion is exposed to the surface of the first seal facing away from the first wall, the first seal and the first wall can be welded in the thickness direction of the first wall, the first seal and the first wall have a large sealing area, so that the airtightness after the first seal is connected to the first wall is higher, and the reliability of the battery cell is higher.

[0090] In such a battery cell, the connection portion is a weld mark. Since the connection portion is exposed to the surface of the first seal facing away from the first wall, the first seal and the first wall can be connected and fixed by penetration welding, so that the first seal and the first wall have a larger sealing area. For example, a wider connection portion is provided, or multiple connection portions surrounding the injection hole are provided to improve the airtightness after the first seal and the first wall are connected, thereby improving the reliability of the battery cell.

[0091] 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.

[0092] 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.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] The housing 211 is a component that cooperates with the end cap 212 to form the internal environment of the battery cell 20. This 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 have various shapes and sizes. Specifically, the shape of the housing 211 can be determined based on 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, and aluminum alloys.

[0102] 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 25 and pressure relief mechanisms can be provided on the end cap 212. The electrode terminal 25 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 portion 230 in the housing 211 from the end cap 212 to reduce the risk of short circuit. For example, the insulating structure may be made of plastic, rubber, or the like.

[0103] 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 the 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. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tab is connected to the electrode terminal 25 through the adapter 26 to form a current loop.

[0104] Please refer to Figure 3, and further refer to Figures 4 and 5. Figure 4 is a schematic diagram of the assembly of the first seal and the first wall provided in some embodiments of the present application, and Figure 5 is a cross-sectional view of the assembled state of the first seal and the first wall provided in some embodiments of the present application. According to some embodiments of the present application, the present application provides a battery cell 20, which includes a shell 21 and a first seal 23. The shell 21 includes a first wall 213, and the first wall 213 is provided with a liquid injection hole 2130; the first seal 23 is used to close the liquid injection hole 2130, and the first seal 23 is welded to the first wall 213 to form a connecting portion 230, which is arranged around the liquid injection hole 2130, and the connecting portion 230 is exposed to the surface of the first seal 23 facing away from the first wall 213.

[0105] The first wall 213 may be the end cover 212 or a wall of the housing 211 . For example, the first wall 213 and other walls form the housing 211 .

[0106] The first sealing member 23 is a metal member, and the material of the first sealing member 23 can be aluminum, aluminum alloy, etc.

[0107] The first sealing member 23 is used to be welded to the first wall 213 . The first sealing member 23 closes the injection hole 2130 to shield the injection hole 2130 and reduce the risk of electrolyte leakage inside the battery cell 20 .

[0108] The connection portion 230 is formed by welding the first sealing member 23 to the first wall 213. The connection portion 230 can be referred to as a weld mark. The connection portion 230 is exposed on the surface of the first sealing member 23 facing away from the first wall 213. This means that the connection portion 230 is exposed on the surface of the first sealing member 23 facing away from the first wall 213. The first sealing member 23 and the first wall 213 can be welded together along the thickness direction Z of the first wall 213 from the side of the first sealing member 23 facing away from the first wall 213.

[0109] The thickness of the first wall 213 and the thickness of the first sealing member 23 can be relatively thin, so that the first sealing member 23 and the first wall 213 can be connected by penetration welding, and the first sealing member 23 and the first wall 213 have a larger connection area.

[0110] The connection portion 230 is disposed around the liquid injection hole 2130 to achieve a sealed connection between the first sealing member 23 and the first wall 213 , thereby sealing the liquid injection hole 2130 .

[0111] According to the battery cell 20 of the embodiment of the present application, the first seal 23 and the first wall 213 can be penetrated and welded along the thickness direction Z of the first wall 213, on the side of the first seal 23 facing away from the first wall 213, so that the connecting portion 230 is exposed on the surface of the first seal 23 facing away from the first wall 213, so that the first seal 23 and the first wall 213 have a larger sealing area, such as providing a wider connecting portion 230, or providing multiple connecting portions 230 surrounding the injection hole 2130, so as to improve the airtightness after the first seal 23 is connected to the first wall 213, thereby improving the reliability of the battery cell 20.

[0112] According to some embodiments of the present application, the connecting portion 230 includes a first portion 2301 and a second portion 2302 sequentially distributed along the thickness direction Z of the first wall 213 . The first portion 2301 is located at the first sealing member 23 , and the second portion 2302 is located at the first wall 213 .

[0113] In the above solution, the first portion 2301 is located on the first sealing member 23 , and the second portion 2302 is located on the first wall 213 , so that the first sealing member 23 is firmly connected to the first wall 213 .

[0114] According to some embodiments of the present application, along the thickness direction Z of the first wall 213 , there is a gap between the orthographic projection of the connecting portion 230 and the edge of the first sealing member 23 .

[0115] In the above scheme, there is a gap between the positive projection of the connecting portion 230 and the edge of the first sealing member 23. The first sealing member 23 can be connected to the first wall 213 by penetration welding to form the connecting portion 230, so that the first sealing member 23 is firmly connected to the first wall 213, thereby improving the reliability of the battery cell 20.

[0116] Referring to FIG. 5 , according to some embodiments of the present application, the thickness of the first wall 213 is H1, and the thickness of the first sealing member 23 is H2, satisfying H2≤H1.

[0117] The first wall 213 includes a first surface 213a facing away from the interior of the battery cell 20 and a second surface 213b facing the interior of the battery cell 20. The thickness of the first wall 213 may be the distance between the first surface 213a and the second surface 213b. The thickness direction Z of the first wall 213 may be parallel to the thickness direction of the first sealing member 23.

[0118] In the above solution, the thickness H1 of the first wall 213 is greater than or equal to the wall thickness H2 of the first seal 23 , so that when the first seal 23 is welded to the first wall 213 , the first wall 213 near the injection hole 2130 is not easily welded through, thereby improving the reliability of the battery cell 20 .

[0119] 4 and 5 , according to some embodiments of the present application, the connection portion 230 includes a first connection portion 230 a and a second connection portion 230 b . The first connection portion 230 a is disposed around the injection hole 2130 , and the second connection portion 230 b is disposed around the first connection portion 230 a .

[0120] The first connection part 230a and the second connection part 230b are two connection parts 230 arranged around the injection hole 2130. The first connection part 230a and the second connection part 230b cooperate to form two blocking structures to reduce the risk of electrolyte leakage from the space between the first seal 23 and the first wall 213.

[0121] The first connection portion 230a and the second connection portion 230b may both be annular structures, and the width of the first connection portion 230a and the width of the second connection portion 230b may be the same or different.

[0122] In the above solution, the first connection part 230a is arranged around the injection hole 2130, and the second connection part 230b is arranged around the first connection part 230a, which can enhance the connection stability between the first sealing member 23 and the first wall 213 and improve the airtightness after the first sealing member 23 and the first wall 213 are connected.

[0123] According to some embodiments of the present application, there may be multiple, for example, three or more, connection parts 230. The multiple connection parts 230 are all arranged around the injection hole 2130, and the multiple connection parts 230 may be multiple concentric ring structures.

[0124] Please refer to Figure 5. According to some embodiments of the present application, the first sealing member 23 has a fitting surface 231 for fitting with the first wall 213. The width of the fitting surface 231 in the first direction X is L. The first direction X intersects with the thickness direction Z of the first wall 213. The thickness of the first wall 213 is H1, satisfying 3*H1≤L≤6*H1.

[0125] In the figure, the direction indicated by the letter X may be a first direction. The first direction X may be a length direction of the first wall 213 or a width direction of the first wall 213. Optionally, the first direction X may be perpendicular to a thickness direction Z of the first wall 213.

[0126] The contact surface 231 is the surface of the first sealing member 23 that contacts the first wall 213. The contact surface 231 is disposed around the liquid injection hole 2130. The contact surface 231 is annular in structure. The width of the contact surface 231 refers to the width of the cross section of the contact surface 231 taken along a plane perpendicular to its extension direction. For example, in FIG5 , the dimension indicated by the letter L is the width of the contact surface 231.

[0127] The size of the fitting surface 231 in the first direction X affects the connection area between the first sealing member 23 and the first wall 213 . The larger the size of the fitting surface 231 in the first direction X, the larger the connection area between the first sealing member 23 and the first wall 213 can be.

[0128] Optionally, L may be, but is not limited to, 3*H1, 3.5*H1, 4*H1, 4.5*H1, 5*H1, 5.5*H1, 6*H1, etc.

[0129] In the above scheme, the width of the fitting surface 231 in the first direction X satisfies the above relationship. On the one hand, the first seal 23 and the first wall 213 have a larger connection area, and multiple connection parts 230 can be set around the injection hole 2130 to ensure that the first seal 23 and the first wall 213 are firmly connected. On the other hand, the first seal 23 occupies a smaller size in the first direction X, reducing material.

[0130] Please refer to Figure 5. According to some embodiments of the present application, the first wall 213 includes a first surface 213a facing away from the interior of the battery cell 20 and a second surface 213b facing the interior of the battery cell 20. The first surface 213a is formed with a groove 2131, and the second surface 213b forms a protrusion 2132 at a position corresponding to the groove 2131. The injection hole 2130 is arranged on the bottom wall 2131a of the groove 2131, and the first sealing member 23 blocks the groove 2131.

[0131] The second surface 213 b and the first surface 213 a may be two surfaces facing each other in the thickness direction Z of the first wall 213 . The second surface 213 b is disposed away from the first sealing member 23 .

[0132] The groove 2131 is formed by the first surface 213a being recessed toward the interior of the battery cell 20 . The depth direction of the groove 2131 may be parallel to the thickness direction Z of the first wall 213 . The injection hole 2130 passes through the bottom wall 2131a of the groove 2131 , that is, the injection hole 2130 passes through the protrusion 2132 .

[0133] The first sealing member 23 blocks the groove 2131 and is connected to the first surface 213 a , so that the first sealing member 23 closes the liquid injection hole 2130 .

[0134] In the above scheme, the first surface 213a and the second surface 213b can be two opposite surfaces in the thickness direction Z of the first wall 213, the first surface 213a is formed with a groove 2131, and the second surface 213b forms a protrusion 2132 at a position corresponding to the groove 2131. The thickness of the first wall 213 can be relatively thin, and the groove 2131 can be stamped, and the processing and manufacturing difficulty is relatively low; the injection hole 2130 is arranged on the bottom wall 2131a of the groove 2131, and the first seal 23 blocks the groove 2131 to reduce the space occupied after the first seal 23 is assembled with the first wall 213.

[0135] 5 , according to some embodiments of the present application, the battery cell 20 further includes a second sealing member 24 , at least a portion of which is disposed in the liquid injection hole 2130 to block the liquid injection hole 2130 .

[0136] The second sealing member 24 is disposed in the liquid injection hole 2130 , and is connected to the hole wall of the liquid injection hole 2130 to seal the liquid injection hole 2130 .

[0137] In the above solution, at least a portion of the second sealing member 24 is disposed in the liquid injection hole 2130 , so as to seal the liquid injection hole 2130 and reduce the risk of electrolyte leakage.

[0138] Please refer to Figure 5. According to some embodiments of the present application, the first wall 213 includes a flange portion 2133, which is arranged on the side of the protrusion 2132 facing the interior of the battery cell 20. The protrusion 2132 has a third surface 213c facing away from the second surface 213b. The injection hole 2130 passes through the flange portion 2133, and a portion of the outer periphery of the second seal 24 is in contact with the inner surface of the flange portion 2133.

[0139] The first wall 213 may be an integrally formed structure. For example, when the first wall 213 is punched to form the liquid injection hole 2130 , a portion of the first wall 213 is folded toward the inside of the battery cell 20 to form a flange portion 2133 .

[0140] The first sealing member 23 is located on a side of the first wall 213 facing away from the interior of the battery cell 20 , so as to reduce the risk of interference between the first sealing member 23 and the flange portion 2133 .

[0141] The inner surface of the flange portion 2133 forms a portion of the liquid injection hole 2130 . The flange portion 2133 is annular and can guide the electrolyte when the electrolyte is injected into the battery cell 20 .

[0142] In the above scheme, the injection hole 2130 passes through the flange portion 2133. The injection hole 2130 can be formed by stamping the first wall 213. The flange portion 2133 is arranged on the side of the protrusion 2132 facing the interior of the battery cell 20, which can reasonably utilize the internal space of the battery cell 20; the flange portion 2133 can be an annular structure, and the outer peripheral portion of the second seal 24 is fitted with the inner surface of the flange portion 2133, so that the second seal 24 has a larger sealing area with the first wall 213 while blocking the injection hole 2130, which can improve the connection sealing between the second seal 24 and the first wall 213 and reduce the risk of electrolyte leakage.

[0143] 5 , according to some embodiments of the present application, along the thickness direction Z of the first wall 213 , the flange portion 2133 protrudes from the third surface 213 c by a dimension H3 , and the thickness of the first wall 213 is H1 , satisfying H1 ≤ H3 ≤ 3*H1.

[0144] The third surface 213c faces the interior of the battery cell 20 , and the flange portion 2133 protrudes from the third surface 213c along the thickness direction Z of the first wall 213 . H3 may be a dimension of the flange portion 2133 protruding from the third surface 213c along the thickness direction Z of the first wall 213 .

[0145] Optionally, H3 may be, but is not limited to, H1, 1.5*H1, 2*H1, 2.5*H1, 3*H1, etc.

[0146] In the above solution, the size of the flange portion 2133 protruding from the third surface 213c satisfies the above relationship, which, on the one hand, provides a larger connection area between the second seal 24 and the flange portion 2133, and on the other hand, reduces the difficulty of processing and manufacturing.

[0147] Referring to FIG. 5 , according to some embodiments of the present application, along the thickness direction Z of the first wall 213 , the dimension of the second sealing member 24 protruding from the third surface 213 c is H4 , satisfying H3 ≤ H4 .

[0148] A portion of the second sealing member 24 protrudes from the third surface 213 c along the thickness direction Z of the first wall 213 , and H4 may be a dimension of the portion of the second sealing member 24 protruding from the third surface 213 c in the thickness direction Z of the first wall 213 .

[0149] In the above scheme, the size of the second seal 24 protruding from the third surface 213c satisfies the above relationship. On the one hand, the second seal 24 and the flange portion 2133 have a larger connection area. On the other hand, the second seal 24 occupies a smaller assembly space, reducing the risk of interference between the second seal 24 and other components.

[0150] 5 , according to some embodiments of the present application, the second sealing member 24 includes a body 241 and a flange 242 . The body 241 blocks the liquid injection hole 2130 , and the flange 242 is formed on the outer peripheral surface of the body 241 and connected to the bottom wall 2131 a of the groove 2131 .

[0151] The main body 241 may be columnar, the outline of the main body 241 matches the outline of the liquid injection hole 2130 , and the portion of the main body 241 located in the liquid injection hole 2130 fits against the hole wall of the liquid injection hole 2130 .

[0152] The flange 242 may be integrally formed with the body 241 , so that the flange 242 and the body 241 are firmly connected.

[0153] The flange 242 is formed on the outer circumferential surface of the body 241 and is disposed around the circumference of the body 241 , so that the flange 242 and the groove bottom wall 2131 a of the groove 2131 have a larger connection area.

[0154] In the above scheme, the flange 242 is formed on the outer peripheral surface of the main body 241, and the flange 242 can limit the movement of the main body 241 toward the inside of the battery cell 20; at the same time, the flange 242 is connected to the bottom wall 2131a of the groove 2131, which can improve the sealing effect between the second sealing member 24 and the first wall 213 and reduce the risk of electrolyte leakage.

[0155] Please refer to Figure 5. According to some embodiments of the present application, the first sealing member 23 is provided with a recessed portion 232, which is recessed toward the groove 2131. Along the thickness direction Z of the first wall 213, the orthographic projection of the recessed portion 232 falls within the orthographic projection of the groove side wall 2131b of the groove 2131.

[0156] The first seal 23 is located on the side of the first wall 213 facing away from the interior of the battery cell 20, so that the first seal 23 conceals the groove 2131. Referring to Figure 5 , the first seal 23 includes a fourth surface 23a and a fifth surface 23b. The fourth surface 23a and the fifth surface 23b are disposed opposite each other in the thickness direction Z of the first wall 213. The fourth surface 23a is the surface of the first seal 23 facing away from the interior of the battery cell 20, and the fifth surface 23b is the surface of the first seal 23 facing the interior of the battery cell 20. The recessed portion 232 is formed by the fourth surface 23a being recessed toward the interior of the battery cell 20. The recessed portion 232 forms a protrusion at the corresponding position on the fifth surface 23b.

[0157] The recessed portion 232 can be a reinforced area of ​​the first seal 23. The recessed portion 232 is recessed toward the groove 2131. Along the thickness direction Z of the first wall 213, the orthographic projection of the recessed portion 232 falls within the orthographic projection of the groove side wall 2131b of the groove 2131, so that part of the limiting portion is located within the groove 2131.

[0158] In the above solution, the provision of the recessed portion 232 can improve the strength of the first seal 23. At the same time, the recessed portion 232 is recessed toward the interior of the battery cell 20 and is located in the groove 2131, which can reduce space occupation and reduce the risk of interference between the first seal 23 and other components.

[0159] According to some embodiments of the present application, the first sealing member 23 has a second protrusion 233 formed on the fourth surface 23a. The second protrusion 233 forms a second recess 234 at a corresponding position on the fifth surface 23b. The second protrusion 233 is disposed around the recess 232. The provision of the second protrusion 233 facilitates stamping and forming of the first sealing member 23 and facilitates stress relief.

[0160] In some embodiments, along the thickness direction Z of the first wall 213 , the projection of the second recessed portion 234 falls into the groove 2131 , so as to facilitate the assembly of the first sealing member 23 and the first wall 213 .

[0161] Referring to FIG. 5 , according to some embodiments of the present application, along the thickness direction Z of the first wall 213 , the orthographic projection of the recess 232 is disposed around the second sealing member 24 .

[0162] The orthographic projection of the recessed portion 232 can be the orthographic projection of the recessed portion 232 onto the bottom wall 2131a of the groove 2131 along the thickness direction Z of the first wall 213. When viewed along the thickness direction Z of the first wall 213, the orthographic projection of the recessed portion 232 is located outside the second sealing member 24 and surrounds the second sealing member 24. A gap may exist between the orthographic projection of the recessed portion 232 and the second sealing member 24, or the orthographic projection of the recessed portion 232 may contact the outer circumferential surface of the second sealing member 24. When the battery cell 20 is assembled, the recessed portion 232 does not interfere with the second sealing member 24.

[0163] In the above solution, part of the recess 232 is disposed in the groove 2131 , and the orthographic projection of the recess 232 is disposed around the second sealing member 24 , which can reduce the risk of interference between the recess 232 and the second sealing member 24 .

[0164] Referring to FIG. 5 , according to some embodiments of the present application, along the first direction X, a minimum distance between an orthographic projection of the recessed portion 232 along the thickness direction Z of the first wall 213 and an orthographic projection of the flange 242 along the thickness direction Z of the first wall 213 is D1, satisfying 0.05 mm ≤ D1 ≤ 0.2 mm, and the first direction X intersects the thickness direction Z of the first wall 213.

[0165] The orthographic projection of the recessed portion 232 along the thickness direction Z of the first wall 213 may be the orthographic projection of the recessed portion 232 along the thickness direction Z of the first wall 213 on the groove bottom wall 2131 a of the groove 2131 .

[0166] The orthographic projection of the flange 242 along the thickness direction Z of the first wall 213 may be the orthographic projection of the flange 242 along the thickness direction Z of the first wall 213 on the groove bottom wall 2131 a of the groove 2131 .

[0167] The bottom wall 2131a of the groove 2131 is perpendicular to the thickness direction Z of the first wall 213. On the bottom wall 2131a of the groove 2131, D1 can be a small distance between the orthographic projection of the recessed portion 232 on the bottom wall 2131a of the groove 2131 and the orthographic projection of the flange 242 on the bottom wall 2131a of the groove 2131.

[0168] Alternatively, D1 may be, but is not limited to, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, etc.

[0169] In the above scheme, the minimum distance between the orthographic projection of the recessed portion 232 along the thickness direction Z of the first wall 213 and the orthographic projection of the flange 242 along the thickness direction Z of the first wall 213 in the first direction X satisfies the above relationship. On the one hand, the risk of interference between the recessed portion 232 and the flange 242 can be reduced. On the other hand, the space occupied by the recessed portion 232 in the first direction X can be reduced.

[0170] According to some embodiments of the present application, along the thickness direction Z of the first wall 213 , the second sealing member 24 is spaced apart from the first sealing member 23 .

[0171] In the above solution, the second sealing member 24 is spaced apart from the first sealing member 23 so that the second sealing member 24 does not interfere with the first sealing member 23 , thereby facilitating assembly of the first sealing member 23 and the first wall 213 .

[0172] According to some embodiments of the present application, the second sealing member 24 is a rubber member.

[0173] In the above solution, the rubber member can undergo elastic deformation, and the second sealing member 24 can be interference-fitted with the injection hole 2130 , so as to enhance the sealing effect between the second sealing member 24 and the hole wall of the injection hole 2130 .

[0174] In some embodiments, the second sealing member 24 may be a T-shaped fluororubber nail.

[0175] According to some embodiments of the present application, the surface of the second sealing member 24 facing away from the interior of the battery cell 20 does not exceed the first surface 213 a of the first wall 213 to save assembly space.

[0176] According to some embodiments of the present application, the thickness of the first wall 213 is H1, satisfying H1≤0.6 mm.

[0177] The thinness of the first wall 213 facilitates the connection of the first seal 23 and the first wall 213 by penetration welding, allowing for a larger connection area between the first seal 23 and the first wall 213, thereby improving the airtightness after the first seal 23 and the first wall 213 are connected. The thinness of the first wall 213 allows the battery cell 20 to be lightweight, thereby meeting the requirement for lightweight use.

[0178] According to some embodiments of the present application, a battery 100 is further provided. The battery 100 includes a battery cell 20 as provided in any of the above embodiments.

[0179] According to some embodiments of the present application, an electric device is further provided. The electric device includes a battery cell 20 or a battery 100 as provided in any of the above embodiments. The battery cell 20 or the battery 100 is used to provide electrical energy.

[0180] According to some embodiments of the present application, referring to Figures 3 to 5 , a battery cell 20 is provided. The battery cell 20 includes a housing 21, electrode terminals 25, an electrode assembly 22, a first seal 23, and a second seal 24. The housing 21 includes a shell 211 and an end cap 212. The end cap 212 seals the opening of the housing 211. The electrode terminals 25 are disposed on the end cap 212. The electrode assembly 22 and the electrolyte are contained within the housing 21. The housing 21 includes a first wall 213, which is provided with an injection hole 2130. The first wall 213 includes a first surface 213a facing away from the interior of the battery cell 20 and a second surface 213b facing the interior of the battery cell 20. The first surface 213a is formed with a groove 2131, and the second surface 213b has a protrusion 2132 formed at a position corresponding to the groove 2131. The injection hole 2130 is provided on the bottom wall 2131a of the groove 2131 and extends through the bottom wall 2131a. The first wall 213 includes a flange portion 2133 located on the side of the protrusion 2132 facing the interior of the battery cell 20. The injection hole 2130 extends through the flange portion 2133. The second seal 24 includes a body 241 and a flange 242. The contour of the body 241 matches the contour of the injection hole 2130, and the outer circumference of the body 241 conforms to the wall of the injection hole 2130. The flange 242 is formed on the outer circumference of the body 241 and is arranged around the circumference of the body 241. The flange 242 is connected to the bottom wall 2131a of the groove 2131, and a portion of the body 241 is located within the injection hole 2130. The thickness of the first wall 213 is H1, where H1 ≤ 0.6 mm. Along the thickness direction Z of the first wall 213, the dimension of the flange portion 2133 protruding from the third surface 213c is H3, satisfying the following conditions: H1 ≤ H3 ≤ 3*H1.

[0181] According to the battery cell 20 of the embodiment of the present application, the first wall 213 is relatively thin. The first seal 23 and the first wall 213 can be welded together along the thickness direction Z of the first wall 213, on the side of the first seal 23 facing away from the first wall 213, so that the connection portion 230 is exposed on the surface of the first seal 23 facing away from the first wall 213, thereby ensuring a larger sealing area between the first seal 23 and the first wall 213. The second seal 24 is disposed within the injection hole 2130 and is in contact with the inner surface of the flange portion 2133, thereby ensuring a larger connection area between the second seal 24 and the first wall 213. The second seal 24 can block the injection hole 2130. The coordinated use of the first seal 23 and the second seal 24 can reduce the risk of electrolyte leakage and improve the reliability of the battery cell 20.

[0182] 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: The housing comprises a first wall, wherein the first wall is provided with a liquid injection hole; The first sealing member is used to close the injection hole. The first sealing member is welded to the first wall to form a connecting portion. The connecting portion is arranged around the injection hole and is exposed to a surface of the first sealing member that is away from the first wall.

2. The battery cell according to claim 1, wherein: The connecting portion includes a first portion and a second portion sequentially distributed along the thickness direction of the first wall, the first portion is located at the first sealing member, and the second portion is located at the first wall.

3. The battery cell according to claim 1 or 2, wherein: Along the thickness direction of the first wall, there is a gap between the orthographic projection of the connecting portion and the edge of the first sealing member.

4. The battery cell according to any one of claims 1 to 3, wherein: The thickness of the first wall is H1, and the thickness of the first sealing member is H2, satisfying H2≤H1.

5. The battery cell according to any one of claims 1 to 4, wherein: The connecting portion includes a first connecting portion and a second connecting portion, wherein the first connecting portion is disposed around the liquid injection hole, and the second connecting portion is disposed around the first connecting portion.

6. The battery cell according to claim 5, wherein: The first sealing member has a fitting surface for fitting with the first wall, the fitting surface has a width L in a first direction, the first direction intersects with a thickness direction of the first wall, the thickness of the first wall is H1, and 3*H1≤L≤6*H1 is satisfied.

7. The battery cell according to any one of claims 1 to 6, wherein: The first wall includes a first surface facing away from the interior of the battery cell and a second surface facing the interior of the battery cell, the first surface is formed with a groove, the second surface forms a protrusion at a position corresponding to the groove, the injection hole is arranged on the bottom wall of the groove, and the first sealing member covers the groove.

8. The battery cell according to claim 7, wherein: The battery cell further includes a second sealing member, at least a portion of which is disposed in the liquid injection hole to block the liquid injection hole.

9. The battery cell according to claim 8, wherein: The first wall includes a flange portion, which is arranged on the side of the protrusion facing the battery cell. The protrusion has a third surface facing away from the second surface. The flange portion protrudes from the third surface. The injection hole passes through the flange portion, and a portion of the outer periphery of the second seal is in contact with the inner surface of the flange portion.

10. The battery cell according to claim 9, wherein: Along the thickness direction of the first wall, the dimension of the flange portion protruding from the third surface is H3, and the wall thickness of the first wall is H1, satisfying H1≤H3≤3*H1.

11. The battery cell according to claim 10, wherein: Along the thickness direction of the first wall, the dimension of the second sealing member protruding from the third surface is H4, satisfying H3≤H4.

12. The battery cell according to any one of claims 9 to 11, wherein: The second sealing member includes a body and a flange, wherein the body blocks the liquid injection hole, and the flange is formed on the outer peripheral surface of the body and connected to the bottom wall of the groove.

13. The battery cell according to claim 12, wherein: The first sealing member is provided with a recessed portion, which is recessed toward the groove. Along the thickness direction of the first wall, the orthographic projection of the recessed portion falls within the orthographic projection of the groove side wall of the groove.

14. The battery cell according to claim 13, wherein: Along the thickness direction of the first wall, the orthographic projection of the recessed portion is arranged around the second sealing member.

15. The battery cell according to claim 14, wherein: Along the first direction, the minimum distance between the orthographic projection of the recess along the thickness direction of the first wall and the orthographic projection of the flange along the thickness direction of the first wall is D1, satisfying 0.05mm≤D1≤0.2mm, and the first direction intersects with the thickness direction of the first wall.

16. The battery cell according to any one of claims 8 to 15, wherein: The second sealing member is spaced apart from the first sealing member along a thickness direction of the first wall.

17. The battery cell according to any one of claims 8 to 16, wherein: The second sealing member is a rubber member.

18. The battery cell according to any one of claims 1 to 17, wherein: The thickness of the first wall is H1, satisfying H1≤0.6 mm.

19. A battery comprising the battery cell according to any one of claims 1 to 18.

20. An electrical device, comprising the battery cell according to any one of claims 1 to 18 or the battery according to claim 19, wherein the battery cell or the battery is used to provide electrical energy.

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