Battery monomer, battery device and electric equipment

Abstract

The utility model discloses a battery monomer, a battery device and electric equipment, the battery monomer comprises an electrode assembly and a shell, the electrode assembly is accommodated in the shell, the shell comprises a first wall, the first wall comprises a first sub-wall and a second sub-wall, the areas, close to each other, of the first sub-wall and the second sub-wall are respectively provided with a concave part and a convex part, at least part of the protruding part protrudes in the thickness direction of the first wall and extends into the concave part, and the first sub-wall is connected with the second sub-wall in a welded mode. The battery monomer provided by the embodiment of the utility model can reduce the processing difficulty and improve the reliability.

Description

Technical Field

[0001] The present application relates to the field of batteries, and particularly to a battery cell, a battery device, and an electrical equipment. Background Art

[0002] With the development of new energy technologies, batteries are increasingly widely used, such as in mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools.

[0003] The development of battery technologies needs to consider various design factors simultaneously. For example, how to improve the reliability of battery cells and reduce the processing difficulty is an important research direction in the field of batteries. Summary of the Utility Model

[0004] The present application provides a battery cell, a battery device, and an electrical equipment, which can improve the reliability.

[0005] In a first aspect, the present application provides a battery cell, including an electrode assembly and a housing. The electrode assembly is accommodated in the housing. The housing includes a housing body and an end cap. The housing body has an opening, and the end cap covers the opening. The housing body includes a first wall, and the first wall includes a first sub-wall and a second sub-wall. In regions where the first sub-wall and the second sub-wall are close to each other, a concave portion and a convex portion are respectively provided. The convex portion at least partially protrudes along the thickness direction of the first wall and extends into the concave portion, and the first sub-wall and the second sub-wall are connected by welding.

[0006] In the technical solution of the embodiment of the present application, the battery cell includes a housing and an electrode assembly disposed in the housing. Among them, the first wall of the housing includes a first sub-wall and a second sub-wall connected by welding. Moreover, the first sub-wall and the second sub-wall form a snap connection through a concave portion and a convex portion that are concavo-convexly arranged along the thickness direction of the first wall and cooperate with each other, and welding is performed on the basis of the snap connection. Thus, the connection strength between the first sub-wall and the second sub-wall can be improved, and the relative positions of the two are more stable. And by making the two sub-walls snap-connected, the process requirements for welding can be reduced, and the processing difficulty of the housing can be reduced.

[0007] According to some embodiments in the embodiments of the present application, both the first sub-wall and the second sub-wall include a main region and a thinning region. The thickness of the main region is greater than that of the thinning region, and the thinning region is located between the two main regions; among them, at least a part of the thinning region of the first sub-wall and the thinning region of the second sub-wall are stacked, the concave portion is provided in the thinning region of the first sub-wall, and the convex portion is provided in the thinning region of the second sub-wall. On the basis of forming a snap connection, the maximum thickness of the first wall is reduced.

[0008] According to some embodiments in the embodiments of the present application, the convex portion protrudes in a direction away from the electrode assembly, and the surface of the main region of the first sub-wall facing the electrode assembly is flush with the surface of the second sub-wall facing the electrode assembly. The possibility of the concave portion and the convex portion affecting the space for arranging the electrode assembly in the housing is reduced.

[0009] According to some embodiments in the embodiments of the present application, the first sub-wall and the second sub-wall are welded together to form a welded portion. Along the thickness direction of the first wall, the orthographic projection of the thinning region of the first sub-wall and the orthographic projection of the thinning region of the second sub-wall have an overlapping region, and the overlapping region covers the orthographic projection of the welded portion. The welding position is set in the region where the two thinning regions are stacked, which facilitates welding connection with a relatively small power.

[0010] According to some embodiments in the embodiments of the present application, the first sub-wall and the second sub-wall are welded together to form a welded portion. The welded portion extends along a first direction, and the first direction intersects with the thickness direction of the first wall; both the concave portion and the convex portion extend along the first direction, or the first sub-wall includes a plurality of concave portions arranged at intervals along the first direction, and the second sub-wall includes a plurality of convex portions arranged at intervals along the first direction, and the plurality of convex portions and the plurality of concave portions are correspondingly arranged. The concave portion and the convex portion can extend continuously along the first direction or include multiple pairs of concave portions / convex portions arranged at intervals.

[0011] According to some embodiments in the embodiments of the present application, at least a part of the housing extends in a ring shape, and the first sub-wall and the second sub-wall are respectively arranged close to opposite ends of the housing in its own extending direction. This facilitates the processing of the housing and reduces the welding process required for the formation of the outer shell.

[0012] According to some embodiments in the embodiments of the present application, the housing further includes two second walls, the two second walls are arranged opposite to each other and are respectively connected to the edges of the first sub-wall and the second sub-wall facing away from each other. Along the circumferential direction of the housing, the size of the second wall is larger than the size of the first wall. The first wall that needs to be welded is arranged on the side surface of the battery cell, reducing the possibility of interference with the electrode assembly.

[0013] According to some embodiments in the embodiments of the present application, the first sub-wall and the second sub-wall are welded together to form a welded portion. Along the direction from the first sub-wall to the second sub-wall, the maximum size of the welded portion is less than or equal to one-fourth of the size of the first wall. Reducing the width of the welded portion improves the processing efficiency.

[0014] According to some embodiments of the present application, the convex portion includes a main convex portion and an extension portion. The main convex portion extends along a first direction and protrudes along the thickness direction of the first wall. The extension portion is connected to the main convex portion and protrudes relative to the main convex portion along a second direction. The first direction, the second direction, and the thickness direction of the first wall are pairwise intersecting. The convex portion can be set as a bent and extended structure to improve the stability of the snap connection between the first sub-wall and the second sub-wall.

[0015] According to some embodiments of the present application, the convex portion includes one main convex portion and two extension portions. The two extension portions protrude relative to the main convex portion in directions away from each other. The convex portion is set as a T shape to further improve the connection reliability.

[0016] In a second aspect, according to an embodiment of the present application, a battery device is provided, including a box body and the battery cell in any one of the embodiments of the first aspect. The battery cell is disposed in the box body.

[0017] In a third aspect, according to an embodiment of the present application, an electrical equipment is provided, including the battery device in any one of the embodiments of the second aspect. The battery device is used to provide electrical energy. Description of the Drawings

[0018] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0019] Figure 1 is a schematic diagram of a vehicle provided by some embodiments of the present application;

[0020] Figure 2 is an exploded view of a battery device provided by some embodiments of the present application;

[0021] Figure 3 is an exploded view of a battery cell provided by some embodiments of the present application;

[0022] Figure 4 is a partial structural schematic diagram of a housing provided by some embodiments of the present application;

[0023] Figure 5 is Figure 4 an enlarged view of the area P shown;

[0024] Figure 6 is a partial structural schematic diagram of a housing provided by some other embodiments of the present application;

[0025] Figure 7 is a partial structural schematic diagram of a housing provided by some other embodiments of the present application.

[0026] Reference Signs:

[0027] 1000 - Vehicle;

[0028] 100 - Battery cell; 200 - Battery device; 300 - Controller; 400 - Motor;

[0029] 10 - Housing; 20 - Electrode assembly; 30 - Box body;

[0030] 11 - First wall; 12 - Second wall; 13 - Housing body; 14 - End cover; 31 - First box body part; 32 - Second box body part; 33 - Accommodating part;

[0031] 111 - First sub - wall; 112 - Second sub - wall; 113 - Recess; 114 - Protrusion; 115 - Main body area; 116 - Thinning area; 117 - Main protrusion; 118 - Extension part;

[0032] X - First direction; Y - Thickness direction of the first wall; Z - Second direction. Detailed Embodiments

[0033] Hereinafter, embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, so they are only examples and cannot be used to limit the protection scope of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein 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 inclusion.

[0035] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary - secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means more than two, unless otherwise specifically and clearly defined.

[0036] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in connection with the embodiments can be included in at least one embodiment of this application. The phrase does not necessarily refer to the same embodiment every time it appears in the specification, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. 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 article generally represents an "or" relationship between the associated objects before and after.

[0038] In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0039] In the description of the embodiments of the present application, for technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the embodiments of the present application.

[0040] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0041] In the embodiments of the present application, the battery cell can be a secondary battery, which refers to a battery cell that can activate the active material and continue to be used through charging after discharging.

[0042] The battery cell can be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium-metal battery, a sodium-metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application do not limit this.

[0043] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are embedded and extracted back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent the short circuit between the positive and negative electrodes and at the same time allow the active ions to pass through.

[0044] 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 provided on at least one surface of the positive electrode current collector.

[0045] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is provided on either or both of the two opposite surfaces of the positive electrode current collector.

[0046] As an example, the positive electrode current collector may be a metal foil or a composite current collector.

[0047] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector.

[0048] As an example, the negative electrode current collector may be a metal foil, a foam metal or a composite current collector.

[0049] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material provided on at least one surface of the negative electrode current collector.

[0050] As an example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is provided on either or both of the two opposite surfaces of the negative electrode current collector.

[0051] As an example, the negative electrode active material may be a negative electrode active material for battery cells 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, and lithium titanate, etc.

[0052] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0053] In some embodiments, the electrode assembly further includes a separator, which is disposed between the positive electrode and the negative electrode.

[0054] In some embodiments, the separator is a separator membrane. The present application does not particularly limit the type of the separator membrane, and any known porous structure separator membrane with good chemical stability and mechanical stability can be selected.

[0055] As an example, the main material of the separator membrane may be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0056] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0057] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. There is no specific limitation on the type of the electrolyte in this application, and it can be selected according to requirements. The electrolyte can be liquid, gel-like or solid.

[0058] In some embodiments, the electrode assembly is provided with tabs, and the tabs can conduct the current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0059] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum-plastic film, etc.

[0060] In some embodiments, functional components such as electrode terminals can be provided on the housing. The electrode terminals can be used to electrically connect to the electrode assembly for outputting or inputting the electrical energy of the battery cell.

[0061] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal prism battery, etc. There is no special limitation in this application.

[0062] The battery device mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0063] In some embodiments, the battery device can be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0064] In some embodiments, the battery device can be a battery pack, and the battery pack includes a box body and battery cells, and the battery cells or battery modules are accommodated in the box body.

[0065] In some embodiments, the box body can be a part of the chassis structure of a vehicle. For example, a part of the box body can become at least a part of the floor of the vehicle, or a part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0066] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage electrical cabinet, etc.

[0067] A battery cell generally includes a housing and an electrode assembly, an electrolyte, etc. disposed in the housing. The housing serves to provide support, accommodation, and protection for the electrode assembly and the like therein. To facilitate the arrangement of structures such as the electrode assembly within the housing, the housing generally includes two structural parts, namely an end cap and a housing body that are snap-fitted and welded together. Among them, the housing body usually needs to be welded at at least one joint to form a required ring-shaped / box-shaped structure.

[0068] On this basis, the applicant has found that, for reliability considerations, the battery cell has certain requirements for the structural strength of the housing, and correspondingly, certain requirements for the connection strength of the welded joints. In existing battery cells, only welding is used to connect the joints, which has relatively high requirements for the welding process and is prone to problems such as misalignment and deformation.

[0069] In view of this, the embodiments of the present application provide a technical solution. By providing a structural component with a concave-convex fit at the joint of the housing, it can form a dual connection and fixation of snap connection and welding, reduce the requirements for the welding process, and improve reliability.

[0070] The technical solution described in the embodiments of the present application is applicable to battery devices and electrical equipment using battery devices. The electrical equipment includes, for example, mobile phones, portable devices, laptop computers, battery-powered vehicles, electric vehicles, ships, spacecraft, electric toys, and power tools, etc. Among them, spacecraft includes, for example, airplanes, rockets, space shuttles, and spaceships, etc. Electric toys include, for example, fixed or mobile electric toys, specifically, for example, game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc. Power tools include, for example, metal-cutting power tools, grinding power tools, assembly power tools, and railway power tools, specifically, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers.

[0071] The battery cell described in the embodiments of the present application is not limited to the above-described electrical equipment. However, for the sake of simplicity of description, the following embodiments will be described by taking an electric vehicle as an example.

[0072] Please refer to Figure 1 , Figure 1A simplified schematic diagram of a vehicle provided for some embodiments of the present application. The vehicle 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, an extended-range vehicle, etc. A battery device 200 can be provided inside the vehicle 1000. Specifically, for example, the battery device 200 can be provided at the bottom, the front end, or the rear end of the vehicle 1000. The battery device 200 can be used to supply power to the vehicle 1000. For example, the battery device 200 can serve as the operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 300 and a motor 400. The controller 300 is used to control, for example, the battery to supply power to the motor 400. The battery device 200 can be used for starting, navigation, etc. of the vehicle 1000. Of course, the battery can also be used to drive the vehicle 1000 to travel, replacing or partially replacing fuel or natural gas to provide drive for the vehicle 1000.

[0073] Figure 2 An exploded schematic diagram of the battery device provided for some embodiments of the present application. As Figure 2 shown, the battery device 200 includes a box body 30 and battery cells 100. The battery cells 100 are accommodated in the box body 30.

[0074] The box body 30 is used to accommodate the battery cells 100, and the box body 30 can be of various structures. In some embodiments, the box body 30 can include a first box body part 31 and a second box body part 32. The first box body part 31 and the second box body part 32 cover each other, and the first box body part 31 and the second box body part 32 jointly define a receiving part 33 for accommodating the battery cells 100. The second box body part 32 can be a hollow structure with an opening 224 at one end. The first box body part 31 is a plate-like structure. The first box body part 31 covers the opening 224 side of the second box body part 32 to form the box body 30 with the receiving part 33. Both the first box body part 31 and the second box body part 32 can also be hollow structures with an opening 224 on one side. The opening 224 side of the first box body part 31 covers the opening 224 side of the second box body part 32 to form the box body 30 with the receiving part 33. Of course, the first box body part 31 and the second box body part 32 can be of various shapes, such as a cylinder, a cuboid, etc.

[0075] In the battery, the number of battery cells 100 can be one or multiple. If there are multiple battery cells 100, the multiple battery cells 100 can be connected in series, in parallel, or in a series-parallel combination. A series-parallel combination means that there are both series and parallel connections among the multiple battery cells 100. The multiple battery cells 100 can be directly connected in series, in parallel, or in a series-parallel combination together, and then the whole formed by the multiple battery cells 100 is accommodated in the box body 30. Of course, it can also be that multiple battery cells 100 are first connected in series, in parallel, or in a series-parallel combination to form battery modules, and then the multiple battery modules are connected in series, in parallel, or in a series-parallel combination to form a whole and are accommodated in the box body 30.

[0076] In some embodiments, there are multiple battery cells 100. The multiple battery cells 100 are first connected in series, parallel, or in a hybrid connection to form a battery module. Then, multiple battery modules are connected in series, parallel, or in a hybrid connection to form an entirety and are accommodated in the box body 30.

[0077] Next, in combination with the attached Figure 3 to the attached Figure 7 the structures of the battery cell 100, the battery device 200, and the electrical equipment will be described.

[0078] Please refer to Figures 3 to 5 , Figure 3 which is an exploded view of the battery cell provided in some embodiments of the present application, Figure 4 which is a partial structural schematic diagram of the outer shell provided in some embodiments of the present application, Figure 5 is Figure 4 an enlarged view of the area P shown.

[0079] In a first aspect, the present application provides a battery cell 100, including an electrode assembly 20 and an outer shell 10. The electrode assembly 20 is accommodated in the outer shell 10. The outer shell 10 includes a housing 13 and an end cap 14. The housing 13 has an opening, and the end cap 14 covers the opening. The housing 13 includes a first wall 11. The first wall 11 includes a first sub-wall 111 and a second sub-wall 112. A recess 113 and a protrusion 114 are respectively provided in the regions where the first sub-wall 111 and the second sub-wall 112 are close to each other. The protrusion 114 at least partially protrudes along the thickness direction Y of the first wall 11 and extends into the recess 113, and the first sub-wall 111 is welded to the second sub-wall 112.

[0080] The embodiments of the present application provide a battery cell 100, including an outer shell 10 for providing functions such as accommodation, protection, and support, and an electrode assembly 20 for realizing electrical functions. The outer shell 10 encloses to form an accommodation cavity, and the electrode assembly 20 is disposed in the accommodation cavity. At the same time, an electrolyte, an insulating film, etc. can also be disposed in the accommodation cavity, and the electrode assembly 20 is at least partially immersed in the electrolyte.

[0081] To facilitate disposing the electrode assembly 20 and the electrolyte, etc. in the outer shell 10, it is optional to set the outer shell 10 to include multiple components such as a housing 13 and an end cap 14, and the components can be connected by welding. The housing 13 can have an opening, and the end cap 14 covers the opening and is optionally welded to the housing 13. Optionally, the housing 13 can be in the shape of a box with one opening, or the housing 13 can be in the shape of a ring with two oppositely disposed openings.

[0082] Optionally, the electrode assembly 20 can be made by stacking or winding a positive electrode tab, a separator, and a negative electrode tab. The separator is disposed between the positive electrode tab and the negative electrode tab to provide functions such as electrical insulation and an ion permeation channel. The positive electrode tab and the negative electrode tab can include a main body portion and an ear portion. The ear portion is led out from the main body portion and electrically connected to the electrode terminal disposed on the housing 10.

[0083] In the embodiment of the present application, the housing 13 includes a first wall 11. The first wall 11 is composed of two sub-walls. The first sub-wall 111 and the second sub-wall 112 are optionally extended along the same plane and are welded and connected at one end close to each other.

[0084] Specifically, the first sub-wall 111 and the second sub-wall 112 are respectively provided with a recess 113 and a protrusion 114. The cross-sectional shapes and dimensions of the two match each other, so that the protrusion 114 can at least partially extend into the recess 113. Among them, the recess 113 is at least partially recessed along the thickness direction Y of the first wall 11. Correspondingly, the protrusion 114 at least partially extends along the thickness direction Y, and the section of the protrusion 114 extending along the thickness direction Y is at least partially located in the recess 113 to form a snap connection.

[0085] This snap connection structure can at least limit the relative positions of the first sub-wall 111 and the second sub-wall 112 in the width direction of the recess 113 / protrusion 114, so that the first sub-wall 111 and the second sub-wall 112 can form a snap connection before welding. By simultaneously using snap connection and welding connection for the first sub-wall 111 and the second sub-wall 112, the reliability of the housing 10 can be effectively improved, and the requirements for the welding process can be reduced.

[0086] Optionally, the cross-sectional shape of the recess 113 can be selected as a rectangle, a triangle, a trapezoid, a semi-circle, a semi-ellipse, etc., as long as it is convenient for processing and forming, and the protrusion 114 can extend into the recess 113 to form a snap connection.

[0087] Optionally, one or more first walls 11 can be provided in the housing 10. Each first wall 11 can be provided with a first sub-wall 111 and a second sub-wall 112. The first sub-wall 111 and the second sub-wall 112 in the same first wall 11 simultaneously use snap connection and welding connection. In each first wall 11, the number of protrusions 114 can correspond to the number of recesses 113. In an embodiment where the first wall 11 includes a plurality of protrusions 114 and a plurality of recesses 113, these recesses 113 and protrusions 114 can be optionally extended in the same direction as the welding track, or can be optionally arranged in an array, or can be optionally arranged at intervals in a specific direction, etc. The present application does not make specific limitations on this, as long as the first sub-wall 111 and the second sub-wall 112 can form a snap connection.

[0088] In the technical solution of the embodiment of the present application, the battery cell 100 includes a housing 10 and an electrode assembly 20 disposed in the housing 10. The first wall 11 of the housing 10 includes a first sub-wall 111 and a second sub-wall 112 connected by welding. Moreover, the first sub-wall 111 and the second sub-wall 112 form a snap connection through a concave portion 113 and a convex portion 114 that are concavely and convexly arranged along the thickness direction Y of the first wall 11 and cooperate with each other, and welding is performed on the basis of the snap connection. Thereby, the connection strength between the first sub-wall 111 and the second sub-wall 112 can be improved, and the relative positions of the two can be made more stable. In addition, by making the two sub-walls snap-connected, the process requirements for welding can be reduced, and the processing difficulty of the housing 10 can be reduced.

[0089] Please refer to Figure 6 , Figure 6 which is a schematic diagram of a partial structure of the housing provided in some other embodiments of the present application.

[0090] In some alternative embodiments, both the first sub-wall 111 and the second sub-wall 112 include a main body region 115 and a thinning region 116. The thickness of the main body region 115 is greater than that of the thinning region 116, and the thinning region 116 is located between the two main body regions 115. Among them, the thinning region 116 of the first sub-wall 111 and the thinning region 116 of the second sub-wall 112 are at least partially stacked, the concave portion 113 is disposed in the thinning region 116 of the first sub-wall 111, and the convex portion 114 is disposed in the thinning region 116 of the second sub-wall 112.

[0091] In the first wall 11, both the first sub-wall 111 and the second sub-wall 112 may include a main body region 115 and a thinning region 116. The thickness of the first wall 11 in the main body region 115 is greater than that in the thinning region 116. The main body region 115 and the thinning region 116 do not overlap with each other, and may be arranged adjacently or spaced apart from each other. Optionally, the thickness of the main body region 115 in the first sub-wall 111 may be the same as or similar to the thickness of the main body region 115 in the second sub-wall 112, and the thickness of the thinning region 116 in the first sub-wall 111 may be the same as or similar to the thickness of the thinning region 116 in the second sub-wall 112, so that the overall structural strength of the first wall 11 is more uniform and convenient for processing.

[0092] Exemplarily, the first sub-wall 111 may include a main body region 115 and a thinning region 116, and at the same time, the second sub-wall 112 may similarly include a first main body region 115 and a thinning region 116. Along the arrangement direction of the first sub-wall 111 and the second sub-wall 112, the two thinning regions 116 are disposed between the two main body regions 115, and the two thinning regions 116 are at least partially stacked, and the convex portion 114 and the concave portion 113 are respectively located in the stacked region of the two thinning regions 116, so that the two can be snap-connected.

[0093] Optionally, when setting the thinning region 116, the sum of the thicknesses of the thinning region 116 of the first sub-wall 111 and the thinning region 116 of the second sub-wall 112 can be made less than or equal to the thicknesses of the two main regions 115, so as to reduce the possibility that the clamping connection bulges inward or outward and occupies space. The thickness of the thinning region 116 in the first sub-wall 111 can be made greater than the thickness of the thinning region 116 in the second sub-wall 112, so as to provide a relatively sufficient setting space for the recess 113 in the thickness direction Y of the first wall 11.

[0094] By setting both the first sub-wall 111 and the second sub-wall 112 to have a thinning region 116 with a relatively thin thickness, the maximum thickness of the first wall 11 can be reduced on the basis of forming a clamping connection.

[0095] In some alternative embodiments, the convex portion 114 protrudes in a direction away from the electrode assembly 20, and the surface of the main region 115 of the first sub-wall 111 facing the electrode assembly 20 is flush with the surface of the second sub-wall 112 facing the electrode assembly 20.

[0096] The first sub-wall 111 and the second sub-wall 112 in the first wall 11 are respectively provided with a recess 113 and a convex portion 114, and the two cooperate with each other to form a clamping connection. On this basis, the convex portion 114 in the second sub-wall 112 can protrude in a direction away from the electrode assembly 20. Correspondingly, the opening of the recess 113 in the first sub-wall 111 can be located on the side of its own bottom facing the electrode assembly 20.

[0097] Further, the thickness of the thinning region 116 in the first wall 11 is less than the thickness of the main region 115. In the first sub-wall 111 provided with the recess 113, along the thickness direction Y of the first wall 11, the thinning region 116 can be disposed to be biased toward the side away from the electrode assembly 20. Optionally, the surface of the thinning region 116 facing away from the electrode assembly 20 is flush with the surface of the main region 115 facing away from the electrode assembly 20. In the second sub-wall 112 provided with the convex portion 114, along the thickness direction Y of the first wall 11, the thinning region 116 can be disposed to be biased toward the side close to the electrode assembly 20. Optionally, the surface of the thinning region 116 close to the electrode assembly 20 is flush with the surface of the main region 115 close to the electrode assembly 20. Thereby, it can further facilitate the processing of the first wall 11 and the formation of a clamping connection.

[0098] Optionally, on the basis of the foregoing stacked thinning regions 116, the surface of the main region 115 of the first sub-wall 111 close to the electrode assembly 20 can be made flush with the surface of the second sub-wall 112 as a whole close to the electrode assembly 20, that is, the inner surface of the main region 115 of the first sub-wall 111 is flush with the inner surface of the second sub-wall 112, so that the inner surface of the first wall 11 as a whole is flat and does not have a protruding structure.

[0099] By making the protrusion 114 protrude in a direction away from the electrode assembly 20 and the inner surface of at least a portion of the first sub-wall 111 being flush with the inner surface of the second sub-wall 112, the possibility of the recess 113 and the protrusion 114 affecting the space in which the electrode assembly 20 is arranged in the outer shell 10 can be reduced, thereby reducing the possibility of causing adverse interference to the energy density of the battery cell 100.

[0100] In some optional embodiments, the first sub-wall 111 is welded to the second sub-wall 112 to form a fusion bond, and along the thickness direction Y of the first wall 11, the orthographic projection of the thinning area 116 of the first sub-wall 111 and the orthographic projection of the thinning area 116 of the second sub-wall 112 have an overlapping area, and the overlapping area covers the orthographic projection of the fusion bond.

[0101] In the embodiment of the present application, the first sub-wall 111 and the second sub-wall 112 are connected by both snap-fitting and welding. After welding, a first welding portion can be formed. The first welding portion extends along the first direction X and can be optionally configured to have the same or similar size as the first wall 11 in this direction so that the force is evenly applied everywhere.

[0102] On this basis, along the thickness direction Y of the first wall 11, the orthographic projection of the welded portion can be covered by the overlapping area of ​​the orthographic projections of the thinning areas 116 of the two sub-walls, that is, when welding is performed, the welded portion formed is located in the thinning areas 116 of the two sub-walls, and the two thinning areas 116 are welded and connected. The welded portion can cover part of the convex portion 114 and part of the concave portion 113, or, in an embodiment where the width of the thinning area 116 allows, the welded portion can be staggered with the convex portion 114 and the concave portion 113.

[0103] By arranging the welded portion in the thinned regions 116 of the two sub-walls, the power required for welding can be effectively reduced, thereby improving the overall processing efficiency of the housing 10 and the battery cell 100 .

[0104] In some optional embodiments, the first sub-wall 111 and the second sub-wall 112 are welded and connected to form a fusion portion, which extends along a first direction X, and the first direction X is arranged to intersect with the thickness direction Y of the first wall 11; the recess 113 and the protrusion 114 both extend along the first direction X, or the first sub-wall 111 includes a plurality of recesses 113 arranged at intervals along the first direction X, and the second sub-wall 112 includes a plurality of protrusions 114 arranged at intervals along the first direction X, and the plurality of protrusions 114 and the plurality of recesses 113 are arranged correspondingly.

[0105] As described above, the first sub-wall 111 and the second sub-wall 112 can be optionally welded together to form a welded portion extending in the first direction X, and the concave portion 113 and the convex portion 114 can be optionally coextensive and continuous with the welded portion in the same direction, or the concave portion 113 and the convex portion 114 can be spaced apart in the first direction X.

[0106] Specifically, the concave portion 113 and the convex portion 114 can extend continuously in the first direction X, and their dimensions can be the same as or similar to the dimensions of the first wall 11 in this direction. In this embodiment, the first wall 11 can be provided with a snap structure, which is composed of a convex portion 114 and a concave portion 113, or the first wall 11 can be provided with multiple pairs of snap structures, and these snap structures are arranged in sequence along the direction from the first sub-wall 111 to the second sub-wall 112. By setting the snap structure to extend continuously in the first direction X, the snap connection can be made stable and reliable, and the first wall 11 as a whole can have good structural strength.

[0107] Alternatively, the first wall 11 can be provided with multiple convex portions 114 and multiple concave portions 113, and these convex portions 114 and concave portions 113 can be spaced apart in the first direction X to form multiple pairs of cooperating snap structures. In this embodiment, the convex portion 114 and the concave portion 113 can be optionally arranged in one-to-one correspondence, or one concave portion 113 can correspond to multiple convex portions 114. By spacing multiple snap structures apart in the first direction X, the overall weight of the housing 10 can be reduced and materials can be saved. At the same time, through the spaces between multiple snap structures, relative position limitation of the first sub-wall 111 and the second sub-wall 112 in the first direction X can be provided, further improving the stable reliability of the snap connection.

[0108] Optionally, in an embodiment where the first wall 11 is provided with multiple spaced-apart snap structures, the multiple snap structures can be arranged in one or more columns spaced apart in the first direction X, and / or the multiple snap structures can also be arranged in an array.

[0109] In some alternative embodiments, at least a part of the housing extends in a ring shape, and the first sub-wall 111 and the second sub-wall 112 are respectively disposed near opposite ends of the housing in its own extending direction.

[0110] Optionally, in an embodiment where the housing extends continuously along its circumference and includes only one main structure, the first sub-wall 111 and the second sub-wall 112 are respectively disposed at opposite ends of the housing in its own extending direction, and a complete ring structure is formed through the welded connection between the first sub-wall 111 and the second sub-wall 112. Alternatively, in an embodiment where the housing includes multiple parts, first sub-walls 111 and second sub-walls 112 can be respectively disposed at opposite ends of each part in its own extending direction, and a ring structure that is sequentially connected end to end is formed through the welded connection between adjacent parts.

[0111] By setting the housing to be annular and arranging the two sub-walls at opposite ends respectively, the housing can be easily processed and the welding process required for the formation of the outer shell 10 can be reduced.

[0112] In some alternative embodiments, the housing further includes two second walls 12, which are arranged oppositely and are respectively connected to the edges of the first sub-wall 111 and the second sub-wall 112 facing away from each other. Along the circumferential direction of the housing, the size of the second wall 12 is larger than that of the first wall 11.

[0113] In the housing, in addition to the first wall 11 that needs to be welded, two second walls 12 can also be provided, and these two second walls 12 can be respectively connected to opposite sides of the first wall 11. Taking the housing as a whole being rectangular as an example, the housing can include two first walls 11 and two second walls 12. Specifically, the two oppositely arranged wall portions can have the same size, and the two opposite sides of each first wall 11 in the circumferential direction of the housing can be respectively connected to the two second walls 12.

[0114] In the embodiment where the housing includes two first walls 11 and two second walls 12, the two first walls 11 are arranged oppositely, and the two second walls 12 are arranged oppositely. The housing as a whole can include two parts, where each part includes a second wall 12 and the first sub-wall 111 / second sub-wall 112 respectively arranged on opposite sides of the second wall 12. The sub-walls at both ends of the two parts are respectively welded to form a complete annular housing.

[0115] On this basis, along the circumferential direction of the housing, the size of the two second walls 12 connected to opposite sides of the first wall 11 can be larger than that of the first wall 11. Still taking the housing as a rectangular ring as an example, the second wall 12 can be the larger front surface, and the first wall 11 can be the smaller side surface.

[0116] According to the arrangement mode of multiple battery cells 100 in the battery device 200 and the structural shape of the electrode assembly 20 in the battery cell 100, by arranging the first wall 11 that needs to be welded on the smaller side of the battery cell 100, the influence on the overall energy density of the battery cell 100 can be further reduced, and at the same time, the possibility of interfering with the arrangement positions of multiple battery cells 100 in the battery device 200 can be reduced.

[0117] In some alternative embodiments, the first sub-wall 111 and the second sub-wall 112 are welded to form a welded joint, and along the direction from the first sub-wall 111 to the second sub-wall 112, the maximum size of the welded joint is less than or equal to one-fourth of the size of the first wall 11.

[0118] As described above, a fusion joint may be formed at the welded joint between the first sub-wall 111 and the second sub-wall 112. The fusion joint may extend along the first direction X, and its extension dimension may be the same as or similar to the dimensions of the first sub-wall 111 and the second sub-wall 112 in this direction. On this basis, the dimension of the fusion joint in the direction pointing from the first sub-wall 111 to the second sub-wall 112, that is, the width of the fusion joint, may be less than or equal to one-fourth of the dimension of the entire first wall 11 in this direction.

[0119] Optionally, along its own extension trajectory, the width dimensions of each part of the fusion joint may remain the same or similar, so that the strength of the welded connection is uniform and reliable. At the same time, the welding dimension of the fusion joint may be set according to parameters such as the required welded connection strength, and its maximum width should be less than one-fourth of the overall width of the first wall 11, reducing the possibility of reduced processing efficiency caused by an overly wide fusion joint.

[0120] Please refer to Figure 7 , Figure 7 which is a schematic partial structure diagram of the housing provided by some other embodiments of the present application.

[0121] In some alternative embodiments, the convex portion 114 includes a main protruding portion 117 and an extension portion 118. The main protruding portion 117 extends along the first direction X and protrudes along the thickness direction Y of the first wall 11. The extension portion 118 is connected to the main protruding portion 117 and protrudes relative to the main protruding portion 117 along the second direction Z. The first direction X, the second direction Z, and the thickness direction Y of the first wall 11 intersect pairwise.

[0122] On the basis that the concave portion 113 and the convex portion 114 are respectively provided on the first sub-wall 111 and the second sub-wall 112 and the concave portion 113 and the convex portion 114 are engaged with each other, the strength of the snap connection can be further improved by adjusting the structure of the convex portion 114. Specifically, the convex portion 114 may include a main protruding portion 117 and an extension portion 118 provided on the main protruding portion 117. Among them, the main protruding portion 117 is connected to the supporting structure in the thinning area 116 of the second sub-wall 112 that extends in the same direction as the main body area 115. The main protruding portion 117 may extend along the first direction X and protrude along the thickness direction Y from the supporting structure. The extension portion 118 may be connected to one end of the main protruding portion 117 away from the supporting structure and protrude from the main protruding portion 117 in other directions intersecting with the thickness direction Y of the first wall 11.

[0123] Optionally, the same second sub-wall 112 may be provided with one or more main protrusions 117, and each main protrusion 117 may be connected with one or more extensions 118. By providing the extension 118 in the protrusion 114, and making the protruding direction of the extension 118 intersect with the thickness direction Y of the first wall 11, the snap connection between the protrusion 114 and the recess 113 can provide a positioning function in the thickness direction Y of the first wall 11, that is, in addition to the positioning function within the plane where the first wall 11 is located, the snap connection between the protrusion 114 and the recess 113 can also reduce the possibility of relative displacement between the first sub-wall 111 and the second sub-wall 112 in the thickness direction Y.

[0124] It is understood that in the embodiment where the convex portion 114 includes the main protruding portion 117 and the extending portion 118, the shape of the concave portion 113 should match the convex portion 114. In the process of snapping the convex portion 114 into the concave portion 113, the extension dimension of the concave portion 113 along the first direction X can be made the same as the extension dimension of the first wall 11 in the same direction, and then the first sub-wall 111 and the second sub-wall 112 are relatively moved along the first direction X, so that the convex portion 114 is inserted into the concave portion 113 along the first direction X. Alternatively, the convex portion 114 itself can have a certain elastic deformation ability by adjusting parameters such as the material or thickness of the convex portion 114, and then it is inserted into the concave portion 113 along the thickness direction Y, and after entering the concave portion 113, it stretches to form a preset shape.

[0125] Optionally, in an embodiment where the protrusion 114 includes an extension portion 118, the extension portion 118 may extend along a specific plane, or the extension portion 118 may have an inflection point, such as forming a spiral shape in a cross section, thereby further improving the stability of the clamping.

[0126] By configuring the protrusion 114 as a structure that is at least partially bent and extended, the stability of the snap-fit ​​connection between the first sub-wall 111 and the second sub-wall 112 can be further improved.

[0127] In some optional embodiments, the protrusion 114 includes a main protrusion 117 and two extension portions 118 , and the two extension portions 118 are respectively protruded in directions away from each other relative to the main protrusion 117 .

[0128] In the embodiment where the protrusion 114 includes the extension portion 118, each protrusion 114 may include a main protrusion 117 and two extension portions 118, and the two extension portions 118 extend opposite to each other, thereby enabling the protrusion 114 to form a "T"-shaped cross-section in a cross section perpendicular to the first direction X. Figure 7 As shown, Figure 7FIG. 0 is a schematic structural view obtained by observing the housing along the first direction X. Among them, two extending portions 118 extending in opposite directions can be connected to the same side end of the main protruding portion 117. Taking the direction in this drawing as an example, the two extending portions 118 extending to the left and right (along the second direction Z) are both connected to the lower end (one end in the thickness direction Y) of the main protruding portion 117, forming a structure similar to an inverted "T" shape.

[0129] Optionally, to facilitate the snap connection between the convex portion 114 and the concave portion 113, the two extending portions 118 extending in opposite directions in the same convex portion 114 can have different extension sizes, that is, the two cross arms of the "T" shaped structure can have a long and a short structure form. Thus, by inserting the long side first into the concave portion 113 and the short side subsequently, the convex portion 114 can be snap-connected to the concave portion 113 along the thickness direction Y of the first wall 11 with less deformation of the convex portion 114.

[0130] By setting the convex portion 114 as a "T" shape, the connection reliability can be further improved, especially the positioning reliability in the thickness direction Y of the first wall 11.

[0131] In a second aspect, according to an embodiment of the present application, a battery device 200 is provided, including a box body 30 and the battery cell 100 in any embodiment of the first aspect, and the battery cell 100 is disposed in the box body 30.

[0132] In a third aspect, according to an embodiment of the present application, an electrical device is provided, including the battery device 200 in any embodiment of the second aspect, and the battery device 200 is used to provide electrical energy.

[0133] The battery device 200 and the electrical device in the embodiments of the present application have all the beneficial effects of the battery cell 100 in the first aspect. For specific descriptions of the battery cell 100, reference can be made to the above embodiments, and details are not repeated herein.

[0134] An embodiment of the present application provides a battery cell 100, including an electrode assembly 20 and a housing 10. The electrode assembly 20 is accommodated in the housing 10. The housing 10 includes a housing body 13 and an end cover 14. The housing body 13 has an opening, and the end cover 14 covers the opening. The housing body 13 includes a first wall 11. The first wall 11 includes a first sub-wall 111 and a second sub-wall 112. A concave portion 113 and a convex portion 114 are respectively provided in the regions where the first sub-wall 111 and the second sub-wall 112 are close to each other. The convex portion 114 protrudes at least partially along the thickness direction Y of the first wall 11 and extends into the concave portion 113, and the first sub-wall 111 and the second sub-wall 112 are welded together.

[0135] Among them, both the first sub-wall 111 and the second sub-wall 112 include a main body area 115 and a thinning area 116. The thickness of the main body area 115 is greater than that of the thinning area 116, and the thinning area 116 is located between two main body areas 115. Among them, the thinning area 116 of the first sub-wall 111 and the thinning area 116 of the second sub-wall 112 are at least partially stacked, and the concave portion 113 and the convex portion 114 are both arranged in the thinning area 116. The convex portion 114 protrudes in a direction away from the electrode assembly 20, and the surface of the main body area 115 of the first sub-wall 111 facing the electrode assembly 20 is flush with the surface of the second sub-wall 112 facing the electrode assembly 20.

[0136] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the specification of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: Electrode assembly; A shell, wherein the electrode assembly is accommodated in the shell, the shell comprises a shell and an end cover, the shell has an opening, the end cover covers the opening, the shell comprises a first wall, the first wall comprises a first sub-wall and a second sub-wall, the first sub-wall and the second sub-wall are respectively provided with a recess and a protrusion in the area close to each other, the protrusion at least partially protrudes along the thickness direction of the first wall and extends into the recess, and the first sub-wall is welded to the second sub-wall.

2. The battery cell according to claim 1, characterized in that: The first sub-wall and the second sub-wall each include a main body region and a thinned region, the thickness of the main body region is greater than the thickness of the thinned region, and the thinned region is located between the two main body regions; The thinning area of ​​the first sub-wall and the thinning area of ​​the second sub-wall are at least partially stacked, the concave portion is arranged in the thinning area of ​​the first sub-wall, and the convex portion is arranged in the thinning area of ​​the second sub-wall.

3. The battery cell according to claim 2, characterized in that: The convex portion is arranged to protrude in a direction away from the electrode assembly, and a side surface of the main body area of ​​the first sub-wall facing the electrode assembly is flush with a side surface of the second sub-wall facing the electrode assembly.

4. The battery cell according to claim 2, characterized in that: The first sub-wall is welded to the second sub-wall to form a fusion bond. Along the thickness direction of the first wall, the orthographic projection of the thinning area of ​​the first sub-wall and the orthographic projection of the thinning area of ​​the second sub-wall have an overlapping area, and the overlapping area covers the orthographic projection of the fusion bond.

5. The battery cell according to claim 1, characterized in that: The first sub-wall is welded to the second sub-wall to form a fusion joint, the fusion joint extends along a first direction, and the first direction intersects with a thickness direction of the first wall; The concave portion and the convex portion both extend along the first direction, or the first sub-wall includes a plurality of the concave portions arranged at intervals along the first direction, and the second sub-wall includes a plurality of the convex portions arranged at intervals along the first direction, and the plurality of the convex portions and the plurality of the concave portions are respectively arranged correspondingly.

6. The battery cell according to claim 1, characterized in that: The shell at least partially extends in an annular shape, and the first sub-wall and the second sub-wall are respectively arranged close to two opposite end portions of the shell in the circumferential direction thereof.

7. The battery cell according to claim 6, characterized in that: The shell further includes two second walls, which are arranged opposite to each other and respectively connected to the edges of one side of the first sub-wall and the second sub-wall facing away from each other. Along the circumference of the shell, the size of the second wall is larger than that of the first wall.

8. The battery cell according to claim 1, characterized in that: The first sub-wall is connected to the second sub-wall by welding to form a fusion portion. Along the direction from the first sub-wall to the second sub-wall, the maximum size of the fusion portion is less than or equal to one quarter of the size of the first wall.

9. The battery cell according to claim 1, characterized in that: The protrusion includes a main protrusion and an extension portion, the main protrusion extends along a first direction and is protruded along the thickness direction of the first wall, the extension portion is connected to the main protrusion and is protruded along a second direction relative to the main protrusion, and the first direction, the second direction and the thickness direction of the first wall are intersected in pairs.

10. The battery cell according to claim 9, characterized in that: The convex portion includes one main convex portion and two extending portions, and the two extending portions are respectively arranged to protrude in directions away from each other relative to the main convex portion.

11. A battery device, characterized in that: include: Box; A plurality of battery cells according to any one of claims 1 to 10, wherein the battery cells are arranged in the box.

12. An electrical device, characterized in that: The battery device as claimed in claim 11 is used to provide electrical energy.

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