Battery cell, battery, electrical device and method for preparing a battery cell

Abstract

An embodiment of the present application provides a battery cell, a battery, an electrical device, and a preparation method of the battery cell. The battery cell includes a housing, and the housing includes a first part and a second part arranged side by side, and a recess is provided on the second part. A first insulating film is coated on the first part, and a second insulating film is coated on the second part. In the embodiment of the present application, according to the different structures of the first part and the second part on the housing, a first insulating film for coating the first part and a second insulating film for coating the second part are designed respectively. Compared with the solution of only using one insulating film, the first insulating film and the second insulating film in the embodiment of the present application are separately arranged, which can better cover the recess, thereby improving the coating effect on the first part and the second part, reducing the risk of leakage problems of the battery cell, and improving safety.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices, such as mobile phones, laptop computers, battery cars, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools, etc. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and secondary alkaline zinc-manganese battery cells, etc.

[0003] However, during the use of existing battery cells, leakage problems are likely to occur, leading to potential safety hazards. Summary of the Invention

[0004] The present application provides a battery cell, a battery, an electrical device, and a method for manufacturing a battery cell, which can improve safety.

[0005] In a first aspect, an embodiment of the present application provides a battery cell. The battery cell includes a housing, the housing includes a first part and a second part arranged side by side, and a recess is provided on the second part. A first insulating film is coated on the first part, and a second insulating film is coated on the second part.

[0006] In the embodiment of the present application, according to the different structures of the first part and the second part on the housing, a first insulating film for coating the first part and a second insulating film for coating the second part are designed. Compared with the solution of using only one insulating film, the first insulating film and the second insulating film in the embodiment of the present application are separately arranged, which can better cover the recess, thereby improving the coating effect on the first part and the second part, reducing the risk of leakage problems of the battery cell, and improving safety.

[0007] In some embodiments, the first part and the second part are arranged side by side along a first direction, and the first insulating film wraps around the first part around an axis parallel to the first direction.

[0008] In the embodiment of the present application, the first insulating film is arranged around the axis, so that the first insulating film can surround and cover the outer peripheral side of the first part and simultaneously cover multiple surfaces of the first part, thereby better achieving the coating effect on the first part.

[0009] In some embodiments, a single first insulating film forms a ring structure surrounding the part.

[0010] In the embodiments of the present application, the annular structure formed by a single first insulating film can surround the first part, so that the outer peripheral side of the first part can be completely covered, realizing the complete coating of the first part, thereby further enhancing the insulation effect of the battery cell at the position of the first part and improving the safety of the battery cell.

[0011] In some embodiments, the number of the first insulating films is multiple, and the multiple first insulating films are connected end to end in sequence to form an annular structure surrounding the first part.

[0012] In the embodiments of the present application, by connecting the multiple first insulating films end to end, an annular structure capable of surrounding the first part is formed, which can ensure the coating effect on the first part. At the same time, when a first insulating film is damaged, only a few first insulating films can be replaced, which is beneficial to the later maintenance of the battery cell.

[0013] In some embodiments, the head end and the tail end of the first insulating film at least partially overlap to form a first overlapping region.

[0014] In the embodiments of the present application, by arranging the head end and the tail end of the first insulating film to at least partially overlap, a first overlapping region is formed. The existence of the first overlapping region can improve the fitting effect of the first insulating film at the first part. At the same time, since the first insulating film is a double-layer structure in the first overlapping region, the insulation effect of the battery cell at the position of the first overlapping region can be improved, and the risk of electric leakage can be reduced.

[0015] In some embodiments, the first part has a first side surface in the second direction and a first bottom surface in the third direction. The size of the first side surface in the third direction is smaller than the size of the first bottom surface in the second direction. The first direction, the second direction, and the third direction intersect pairwise. Among them, the first overlapping region is located on the first side surface or the first bottom surface.

[0016] In the embodiments of the present application, the first overlapping region is located on the first side surface or the first bottom surface, that is, the entire first overlapping region can be located in the same plane. Compared with the solution where the first overlapping region is located on multiple different planes at the same time, the first overlapping region located on the first side surface or the first bottom surface can make the head end and the tail end of the first insulating film fit and fix better, so that the first insulating film can be relatively flat at the first overlapping region, thereby reducing the risk of fitting failure at the first overlapping region.

[0017] In some embodiments, in some embodiments, the first overlapping region is located on the first side surface, the size of the first overlapping region in the third direction is L1, the size of the first side surface in the third direction is D1, and L1 and D1 satisfy: 2 mm ≤ L1 ≤ D1.

[0018] In the embodiments of the present application, the size of the first overlapping region in the third direction is set to be L1 not less than 2 mm, so as to ensure that the head end and the tail end of the first insulating film can have a first overlapping region with a certain size, reducing the risk of separation of the head end and the tail end. At the same time, in the embodiments of the present application, L1 is also set to be not greater than D1 to ensure that the first overlapping region can be completely located on the first side surface, meeting the actual production requirements.

[0019] In some embodiments, the first overlapping region is located on the first bottom surface. The size of the first overlapping region in the second direction is L2, and the size of the first bottom surface in the second direction is D2. L2 and D2 satisfy: 4 mm ≤ L2 ≤ D2.

[0020] In the embodiments of the present application, the size of the first overlapping region in the second direction is set to be L2 not less than 4 mm, so as to ensure that the head end and the tail end of the first insulating film can have a first overlapping region with a certain size, reducing the risk of separation of the head end and the tail end. At the same time, in the embodiments of the present application, L2 is also set to be not greater than D2 to ensure that the first overlapping region can be completely located on the first bottom surface, meeting the actual production requirements.

[0021] In some embodiments, the battery cell further includes an electrode assembly disposed in the housing. The electrode assembly includes a main body portion and a tab portion connected to each other. The main body portion has a first surface and a second surface connected to each other. The first surface is disposed opposite to the first bottom surface in the third direction, and the second surface is disposed opposite to the first side surface in the second direction. The size of the second surface in the third direction is smaller than the size of the first surface in the second direction. Among them, the first overlapping region is located on the first bottom surface, and the orthographic projection of the first surface on the first bottom surface and the orthographic projection of the first overlapping region on the first bottom surface are staggeredly distributed.

[0022] In the embodiments of the present application, in order to avoid the problem that the electrode assembly is unevenly stressed due to the different thicknesses at the position of the first overlapping region and other positions on the first insulating film, the orthographic projection of the first surface on the first bottom surface and the orthographic projection of the first overlapping region on the first bottom surface are staggeredly distributed in the embodiments of the present application, that is, the thickness of the first insulating film at the position corresponding to the first surface is kept consistent, thereby improving the use reliability of the battery cell.

[0023] In some embodiments, the second part is located on at least one side of the first part along the first direction. The second part has opposite first and second surfaces in the third direction. The concave portion is recessed inward from the second surface towards the first surface. The second insulating film includes a first sub - portion covering the first surface and a second sub - portion covering the second surface.

[0024] In the embodiment of the present application, according to the structure of the second part, the second insulating film is provided with a first sub - part and a second sub - part. The first sub - part covers the first surface, and the second sub - part covers the second surface. By adjusting the shape and size of the first sub - part and the second sub - part, the second insulating film can better cover the second part, thereby improving the insulation effect of the battery cell at the second part and enhancing the safety of the battery cell.

[0025] In some embodiments, the second sub - part includes a first segment, and a second segment and a third segment located on both sides of the first segment along the second direction. At least one of the second segment and the third segment is arranged to partially overlap with the first segment to form a second overlapping region.

[0026] In the embodiment of the present application, by arranging at least one of the second segment and the third segment to partially overlap with the first segment, a second overlapping region is formed. The existence of the second overlapping region can improve the fitting effect of the second insulating film at the second part. At the same time, since the second insulating film has a double - layer structure at the second overlapping region, the insulation effect of the battery cell at the second overlapping region can be improved, reducing the risk of leakage.

[0027] In some embodiments, the battery cell further includes an electrode assembly disposed in the housing. The electrode assembly includes a main body portion and a tab portion connected to each other. The main body portion has a first surface and a second surface that are connected to each other and intersect. The first surface is disposed opposite to the first surface in the third direction, and the size of the second surface in the third direction is smaller than the size of the first surface in the second direction. Among them, in a plane perpendicular to the third direction, the orthographic projection of the first surface is misaligned with the orthographic projection of the second overlapping region.

[0028] In the embodiment of the present application, in order to avoid the problem of uneven stress on the electrode assembly caused by the different thicknesses at the position of the second overlapping region and other positions on the second insulating film, the orthographic projection of the first surface is misaligned with the orthographic projection of the second overlapping region in the embodiment of the present application, that is, the thickness of the second insulating film at the position corresponding to the first surface is kept consistent, thereby improving the reliability of the battery cell in use.

[0029] In some embodiments, the size L3 of the second overlapping region in the second direction is not greater than 4 mm.

[0030] In the embodiment of the present application, the size L3 of the second overlapping region in the second direction is set to be not greater than 4 mm, reducing the interference effect among the first segment, the second segment, and the third segment, and improving the fitting effect of the second insulating film.

[0031] In some embodiments, the second insulating film has an unfolded state. In the unfolded state, the second insulating film is a sheet - like structure, and the first segment, the second segment, and the third segment are separated from each other and are all connected to the first sub - part.

[0032] In the embodiment of the present application, the first segment, the second segment, and the third segment in the unfolded state are separated from each other. During the transition from the unfolded state to the fitting state, the second segment and the third segment can be fitted towards the direction close to the first segment, thereby forming a second overlapping region. At the same time, the first segment, the second segment, and the third segment are all connected to the first sub-part. Therefore, only a simple cut is required on a sheet-like structure to obtain the second insulating film in the embodiment of the present application, and the preparation process is simple and convenient, which is conducive to large-scale production and manufacturing.

[0033] In some embodiments, the first sub-part includes an avoidance hole for avoiding the protrusion located on the first surface.

[0034] In the embodiment of the present application, an avoidance hole is provided on the first sub-part, and the avoidance hole penetrates through the first sub-part. The protrusion can completely penetrate through the avoidance hole. The existence of the avoidance hole can prevent the second insulating film from wrinkling and warping due to the protrusion, and improve the fitting effect between the second insulating film and the second part.

[0035] In some embodiments, the second insulating film and the first insulating film are overlapped to form a third overlapping region.

[0036] In the embodiment of the present application, by overlapping the second insulating film and the first insulating film, a third overlapping region is formed. The existence of the third overlapping region can improve the fitting effect among the first insulating film, the second insulating film, and the outer shell. At the same time, since the third overlapping region is a double-layer structure, the insulating effect of the battery cell at the third overlapping region can be improved, and the risk of electric leakage can be reduced.

[0037] In some embodiments, the third overlapping region covers the first part.

[0038] In the embodiment of the present application, since the second part is provided with a concave portion, if the third overlapping region is arranged on the second part, the existence of the concave portion may affect the fitting effect between the first insulating film and the second insulating film, resulting in the risk of wrinkling or warping. Therefore, to avoid this situation, the third overlapping region is arranged at the position of the first part in the embodiment of the present application to ensure the flat fitting of the first insulating film and the second insulating film.

[0039] In some embodiments, the dimension L4 of the third overlapping region in the first direction is not less than 4 mm.

[0040] In the embodiment of the present application, the dimension L4 of the third overlapping region in the first direction is set to be not less than 4 mm, so as to ensure the fitting effect between the first insulating film and the second insulating film and reduce the risk of warping at the third overlapping region.

[0041] In some embodiments, there are two first parts, and the two first parts are respectively located on both sides of the second part along the first direction, and the second insulating film wraps around the second part along an axis parallel to the first direction.

[0042] In the embodiments of the present application, the first parts are respectively located on both sides of the second part. When using the second insulating film to wrap the second part, it is impossible to semi-surround and wrap the second insulating film from the edge side of the second part. Therefore, in the embodiments of the present application, the second insulating film wraps around the second part along an axis parallel to the first direction, so that the second insulating film can cover multiple surfaces of the second part, improving the wrapping effect on the second part.

[0043] In some embodiments, the thickness of at least one of the first insulating film and the second insulating film is H, and H satisfies: 0.01 mm ≤ H ≤ 0.5 mm.

[0044] In the embodiments of the present application, the thickness of at least one of the first insulating film and the second insulating film is limited to avoid being too thick or too thin. While ensuring the insulation effect of the outer shell, the energy density of the battery cell is improved to meet the actual use requirements.

[0045] In a second aspect, the embodiments of the present application provide a battery, including a plurality of battery cells in any of the foregoing embodiments. The plurality of battery cells are arranged side by side in the thickness direction of the battery cell, and the recess is used to accommodate the electrode terminals of the battery cell adjacent to the recess.

[0046] In a third aspect, the embodiments of the present application provide an electrical device, including a battery cell in any of the foregoing embodiments, and the battery cell is used to provide electrical energy.

[0047] In a fourth aspect, the embodiments of the present application provide a method for manufacturing a battery cell, including:

[0048] Providing an outer shell, the outer shell includes a first part and a second part arranged side by side, and a recess is provided on the second part;

[0049] Providing a first insulating film and wrapping the first insulating film on the first part;

[0050] Providing a second insulating film and wrapping the second insulating film on the second part.

[0051] Compared with the prior art, the outer shell of the battery cell can be better wrapped, thereby improving the overall insulation performance of the outer shell, reducing the risk of electric leakage of the battery cell, and improving the use safety of the battery cell.

[0052] In some embodiments, providing a first insulating film and wrapping the first insulating film on the first part includes: wrapping the first insulating film around the first part to form an annular structure.

[0053] In the embodiments of the present application, by forming the first insulating film into a circular structure, the first insulating film can better cover the first part, thereby improving the insulation effect at the position of the first part.

[0054] In some embodiments, the second part is located on at least one side of the first part along the first direction. The second part has a relative first surface and a second surface in the third direction. The concave part is formed by inwardly recessing from the second surface towards the direction close to the first surface. The first direction intersects with the third direction.

[0055] The second insulating film includes a first sub - part and a second sub - part that are connected to each other. Providing the second insulating film and covering the second insulating film in the second part includes:

[0056] Cutting the second sub - part so that the second sub - part forms a first segment and second segments and third segments located on both sides of the first segment. The first segment, the second segments, and the third segments are separated from each other and are all connected to the first sub - part.

[0057] Attaching the first sub - part to the first surface;

[0058] Attaching the first segment, the second segments, and the third segments to the second surface so that the first segment, the second segments, and the third segments jointly cover the second surface.

[0059] In the embodiments of the present application, by separating the first segment, the second segments, and the third segments from each other, the first segment, the second segments, and the third segments can be respectively attached to the concave part, thereby reducing or avoiding the appearance of wrinkles. Thus, the attachment effect of the second insulating film can be improved, and the insulation performance of the second part can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required to be used in the embodiments of the present application. Obviously, the following described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained according to the drawings.

[0061] Figure 1 Structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0062] Figure 2 Explosion schematic diagram of a battery provided by some embodiments of the present application;

[0063] Figure 3 Structural schematic diagram of a battery cell provided by some embodiments of the present application;

[0064] Figure 4Schematic structural diagram of a battery cell provided by some embodiments of the present application from another perspective;

[0065] Figure 5 For Figure 4 Schematic cross-sectional structure diagram at A-A in;

[0066] Figure 6 Schematic structural diagram of the outer shell and the first insulating film in the battery cell provided by some embodiments of the present application;

[0067] Figure 7 Schematic structural diagram of the outer shell and the first insulating film in the battery cell provided by some embodiments of the present application;

[0068] Figure 8 For Figure 5 Enlarged structural diagram of area Q in;

[0069] Figure 9 Schematic internal structure diagram of the battery cell provided by some embodiments of the present application;

[0070] Figure 10 For Figure 9 Enlarged structural diagram of area P in;

[0071] Figure 11 Schematic internal structure diagram of the battery cell provided by some embodiments of the present application;

[0072] Figure 12 For Figure 11 Enlarged structural diagram of area M in;

[0073] Figure 13 For Figure 3 Enlarged structural diagram of area N in;

[0074] Figure 14 Schematic structural diagram of the battery cell provided by some embodiments of the present application;

[0075] Figure 15 Schematic structural diagram of the outer shell and the second insulating film in the battery cell provided by some embodiments of the present application;

[0076] Figure 16 Schematic structural diagram of the battery cell provided by some embodiments of the present application;

[0077] Figure 17 For Figure 2 Enlarged structural diagram of area 0 in;

[0078] Figure 18 Flowchart of the preparation method of the battery cell provided by some embodiments of the present application;

[0079] Figures 19 to 21It is a schematic structural diagram of the process of the method for preparing a battery cell provided by some embodiments of the present application;

[0080] Figure 22 It is a flowchart of the method for preparing a battery cell provided by some embodiments of the present application;

[0081] Figures 23 to 25 It is a schematic structural diagram of the process of the method for preparing a battery cell provided by some embodiments of the present application.

[0082] In the drawings, the drawings are not drawn to actual scale.

[0083] In the drawings:

[0084] 1000, vehicle;

[0085] 100, battery; 200, controller; 300, motor; 400, box body; 401, first box body; 402, second box body; 403, accommodating part; 500, battery module; 10, battery cell; 20, busbar member;

[0086] 1, outer shell; 11, first part; 111, first side surface; 112, first bottom surface; 113, second side surface; 114, second bottom surface; 12, second part; 121, first surface; 122, second surface; 1221, protrusion;

[0087] 2, first insulating film;

[0088] 3, second insulating film; 31, first sub - part; 311, avoidance hole; 32, second sub - part; 321, first segment; 322, second segment; 323, third segment;

[0089] 4, electrode assembly; 41, main body part; 411, first face; 412, second face; 42, tab;

[0090] 5, electrode terminal;

[0091] 6, terminal board;

[0092] A1, recess; A2, axis

[0093] B1, first overlapping area; B2, second overlapping area; B3, third overlapping area;

[0094] X, first direction; Y, second direction; Z, third direction. Detailed implementation manners

[0095] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly describe the technical solutions in the embodiments of this application with reference to the accompanying drawings in the embodiments of this application. Apparently, the described embodiments are some, but not all, of the embodiments of this application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in this application without creative efforts shall fall within the scope of protection of this application.

[0096] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those skilled in the technical field 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 accompanying drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of this application or the above accompanying drawings are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0097] Referring to "embodiment" in this application means that a specific feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of this application. The phrase appears in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0098] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled", and "attached" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0099] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0100] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, and other dimensions of various components shown in the accompanying drawings of the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device, are only for illustrative purposes and should not constitute any limitation to this application.

[0101] In this application, "a plurality of" means two or more (including two).

[0102] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, a magnesium-ion battery cell, etc., and the embodiments of this application do not limit this. The battery cell can be in the shape of a cylinder, a flat body, a cuboid or other shapes, etc., and the embodiments of this application do not limit this either. Generally, the battery cell is divided into three types according to the encapsulation method: cylindrical battery cell, square battery cell and soft-pack battery cell, and the embodiments of this application do not limit this either.

[0103] The battery mentioned in the embodiments of this application refers to a single physical module including one or more battery cells to provide a higher voltage and capacity. For example, the battery mentioned in this application may include a battery or a battery pack, etc. The battery generally includes a box body for encapsulating one or more battery cells. The box body can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cell.

[0104] The battery cell includes an electrode assembly and an electrolyte. The electrode assembly is composed of a positive electrode sheet, a negative electrode sheet and a separator. The battery cell mainly works by the movement of metal ions between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode current collector. The positive electrode current collector without the coated positive electrode active material layer protrudes from the positive electrode current collector with the coated positive electrode active material layer. The positive electrode current collector without the coated positive electrode active material layer serves as the positive electrode tab. Taking a lithium-ion battery as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material can be lithium cobaltate, lithium iron phosphate, ternary lithium or lithium manganate, etc. The negative electrode sheet includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector. The negative electrode current collector without the coated negative electrode active material layer protrudes from the negative electrode current collector with the coated negative electrode active material layer. The negative electrode current collector without the coated negative electrode active material layer serves as the negative electrode tab. The material of the negative electrode current collector can be copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that a large current can pass through without fusing, the number of positive electrode tabs is a plurality and they are stacked together, and the number of negative electrode tabs is a plurality and they are stacked together. The material of the separator can be polypropylene (PP) or polyethylene (PE), etc. In addition, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited to this.

[0105] The battery cell further includes a housing for accommodating the electrode assembly and the electrolyte. The housing includes a casing and an end cap connected to the casing. The casing and the end cap form a receiving cavity for accommodating the electrode assembly and the electrolyte. In some embodiments, the battery cell further includes a current collector member for electrically connecting the electrode assembly to the electrode terminal on the end cap.

[0106] During the use of the battery cell, the applicant noticed that the battery cell, especially the battery cell with a special-shaped structure, is prone to leakage problems.

[0107] The applicant's research found that the housing of the battery cell usually needs to be coated with an insulating material to insulate the battery cell from other structures. However, for some battery cells, especially special-shaped battery cells, it is difficult to completely cover some structures on the housing with the existing insulation coating technology. As a result, the battery cell has leakage problems and potential safety hazards.

[0108] Based on the above problems discovered by the applicant, the present application provides a battery cell that can improve the use safety of the battery cell.

[0109] The technical solutions described in the embodiments of the present application are applicable to electrical devices using batteries, such as battery-powered vehicles, electric vehicles, ships, spacecraft, electric toys, and power tools, etc. Among them, spacecraft such as airplanes, rockets, space shuttles, and spacecraft, etc., electric toys include fixed or mobile electric toys, specifically, for example, electric vehicle toys, electric ship toys, and electric airplane toys, etc., and power tools include 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.

[0110] The battery cells described in the embodiments of the present application are not limited to the above-described electrical devices, but for the sake of brevity of description, the following embodiments will be described by taking electric vehicles as an example.

[0111] Please refer to Figure 1, the 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, an extended-range vehicle, etc. A battery 100 can be disposed inside the vehicle 1000. Specifically, for example, the battery 100 can be disposed at the bottom, the front end or the rear end of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as the operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 200 and a motor 300. The controller 200 is used to control, for example, the power supply of the battery to the motor 300. The battery can be used for starting, navigation, etc. of the vehicle 1000. Of course, the battery 100 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.

[0112] Figure 2 An explosion schematic diagram of the battery provided by some embodiments of the present application. As Figure 2 shown, the battery 100 includes a box body 400 and battery cells 10, and the battery cells 10 are accommodated in the box body 400.

[0113] The box body 400 is used to accommodate the battery cells 10, and the box body 400 can have various structures. In some embodiments, the box body 400 can include a first box body part 401 and a second box body part 402. The first box body part 401 and the second box body part 402 cover each other, and the first box body part 401 and the second box body part 402 jointly define a receiving part 403 for accommodating the battery cells 10. The second box body part 402 can be a hollow structure with one end open, and the first box body part 401 is a plate-like structure. The first box body part 401 covers the open side of the second box body part 402 to form the box body 400 with the receiving part 403; both the first box body part 401 and the second box body part 402 can also be hollow structures with one side open, and the open side of the first box body part 401 covers the open side of the second box body part 402 to form the box body 400 with the receiving part 403. Of course, the first box body part 401 and the second box body part 402 can have various shapes, such as a cylinder, a cuboid, etc.

[0114] To improve the sealing performance after the connection between the first box body part 401 and the second box body part 402, a sealing member, such as sealant, sealing ring, etc., can also be provided between the first box body part 401 and the second box body part 402. Assuming that the first box body part 401 covers the top of the second box body part 402, the first box body part 401 can also be called the upper box cover, and the second box body part 402 can also be called the lower box body.

[0115] In the battery 100, there may be one or more battery cells 10. If there are multiple battery cells 10, the multiple battery cells 10 can be connected in series, parallel, or in a combined series-parallel connection. A combined series-parallel connection means that there are both series and parallel connections among the multiple battery cells 10. The multiple battery cells 10 can be directly connected in series, parallel, or in a combined series-parallel connection together, and then the whole formed by the multiple battery cells 10 is accommodated in the box body 400. Of course, it is also possible that the multiple battery cells 10 are first connected in series, parallel, or in a combined series-parallel connection to form battery modules, and then the multiple battery modules are connected in series, parallel, or in a combined series-parallel connection to form a whole and are accommodated in the box body 400. Exemplarily, adjacent battery cells 10 can be connected through the busbar member 20.

[0116] The structure of the battery cell 10 will be described in detail below with reference to the accompanying drawings.

[0117] An embodiment of the present application provides a battery cell 10. Please refer to Figure 3 , the battery cell 10 includes a housing 1. The housing 1 includes a first part 11 and a second part 12 arranged side by side. A recess A1 is provided on the second part 12. The first insulating film 2 is coated on the first part 11, and the second insulating film 3 is coated on the second part 12.

[0118] The first part 11 and the second part 12 are connected to each other and arranged side by side. The number and position of the first part 11 and the second part 12 are not limited in the embodiment of the present application. Exemplarily, there may be two second parts 12, and the two first parts 11 are respectively located on both sides of the first part 11.

[0119] A recess A1 is provided on the second part 12. The recess A1 specifically refers to the area on the second part 12 that is recessed inward relative to the first part 11. The presence of the recess A1 causes the overall surface of the housing 1 to be no longer flat. At this time, if a single insulating film is used to coat the entire housing 1, since the overall surface of the housing 1 is no longer flat, the insulating film cannot completely cover the housing 1, resulting in a leakage problem.

[0120] Therefore, the present application embodiment provides two insulating films, namely the first insulating film 2 and the second insulating film 3. The first insulating film 2 is specifically designed according to the outer contour of the first part 11, so as to improve the coating effect on the first part 11. The second insulating film 3 is specifically designed according to the outer contour of the second part 12, and can better cover the recess A1, so as to improve the coating effect on the second part 12.

[0121] It should be noted that the "coating" mentioned in the embodiments of the present application means that the first insulating film 2 can cover part or all of the first part 11, and the second insulating film 3 can cover part or all of the second part 12. And in addition to the first insulating film 2 and the second insulating film 3, the embodiments of the present application may further include a third insulating film or even more insulating films to improve the coating effect on the housing 1, and the embodiments of the present application do not limit this.

[0122] The embodiments of the present application do not limit the materials of the first insulating film 2 and the second insulating film 3. Exemplarily, at least one of the first insulating film 2 and the second insulating film 3 is a blue film structure.

[0123] The embodiments of the present application do not limit the specific coating method of the first insulating film 2 relative to the first part 11. Exemplarily, the first insulating film 2 can be arranged to surround or semi-surround the first part 11. Similarly, the embodiments of the present application do not limit the specific coating method of the second insulating film 3 relative to the second part 12.

[0124] In addition, the number of the first insulating film 2 and the second insulating film 3 can be one or more, and there may or may not be an overlap between the first insulating film 2 and the second insulating film 3. If there is an overlap between the first insulating film 2 and the second insulating film 3, the overlapping area can be located on the first part 11 or on the second part 12, and the embodiments of the present application do not limit this.

[0125] According to the different structures of the first part 11 and the second part 12 on the housing 1, the embodiments of the present application design the first insulating film 2 for coating the first part 11 and the second insulating film 3 for coating the second part 12 respectively. Compared with the solution of only using one insulating film, the first insulating film 2 and the second insulating film 3 provided in the embodiments of the present application are separately arranged, which can better cover the recess A1, thereby improving the coating effect on the first part 11 and the second part 12, reducing the risk of leakage problems of the battery cell 10, and improving safety.

[0126] In some embodiments, please refer to Figures 3 to 5 , the first part 11 and the second part 12 are arranged side by side along the first direction X, and the first insulating film 2 coats the first part 11 around an axis A2 parallel to the first direction X.

[0127] The first part 11 and the second part 12 are arranged side by side along the first direction X, and at least one of the first part 11 and the second part 12 can be provided with multiple ones. Exemplarily, two second parts 12 are provided, and the two second parts 12 are located on both sides of the first part 11 in the first direction X.

[0128] In the embodiments of the present application, the "axis A2" mentioned refers to a virtual straight line parallel to the first direction X. The first insulating film 2 is disposed around the axis A2 and covers the first part 11. It should be noted that there may or may not be a connection between the axis A2 and the shape of the housing 1. Specifically, if the housing 1 is cylindrical, the axis A2 may coincide with the central axis of the housing 1; if the housing 1 is square or some regular shapes, the axis A2 may coincide with the central axis A2 parallel to the first direction X in the housing 1; however, if the shape of the housing 1 is some irregular shapes, there is no connection between the axis A2 and the housing 1, and at this time, the axis A2 is only a virtual straight line parallel to the first direction X.

[0129] In addition, the first insulating film 2 may completely cover the first part 11 or cover some structures in the first part 11, and the embodiments of the present application do not limit this.

[0130] In the embodiments of the present application, the first insulating film 2 is disposed around the axis A2, so that the first insulating film 2 can surround and cover the outer peripheral side of the first part 11 and simultaneously cover multiple surfaces of the first part 11, thereby better achieving the covering effect on the first part 11.

[0131] In some embodiments, please refer to Figure 3 and Figure 6 , a single first insulating film 2 forms an annular structure surrounding the part.

[0132] The first insulating film 2 includes opposite head and tail ends. The first insulating film 2 is wound around the axis A2, and the head and tail ends are joined together to form an annular structure. Among them, there may or may not be an overlapping area between the head and tail ends of a single first insulating film 2, and the embodiments of the present application do not limit this, as long as a single first insulating film 2 can form a closed annular structure.

[0133] In the embodiments of the present application, the annular structure formed by a single first insulating film 2 can surround the first part 11, so that the outer peripheral side of the first part 11 can be completely covered, achieving complete covering of the first part 11, thereby further enhancing the insulation effect of the battery cell 10 at the position of the first part 11 and improving the safety of the battery cell 10.

[0134] In some embodiments, please refer to Figure 3 and Figure 7 , the number of the first insulating films 2 is multiple, and the multiple first insulating films 2 are connected end to end in sequence to form an annular structure surrounding the first part 11.

[0135] The statement in the embodiments of the present application that "a plurality of first insulating films 2 are connected end to end in sequence to form an annular structure surrounding the first part 11" means that: each first insulating film 2 has a relative head end and a tail end. Among any two adjacent first insulating films 2, the head end of one is connected to the tail end of the other, and the plurality of first insulating films 2 are arranged in sequence according to this rule. Then, the head end of the first insulating film 2 at the frontmost position is connected to the tail end of the first insulating film 2 at the rearmost position, so as to form an annular structure surrounding the first part 11.

[0136] It should be noted that, among two adjacent first insulating films 2 in the annular structure, the head end of one of them may or may not have an overlapping area with the tail end of the other, as long as it satisfies that the plurality of first insulating films 2 can form a closed annular structure.

[0137] In the embodiments of the present application, a plurality of first insulating films 2 are connected end to end to form an annular structure that can surround the first part 11, which can ensure the coating effect on the first part 11. At the same time, when a first insulating film 2 is damaged, only a few first insulating films 2 can be replaced, which is beneficial to the later maintenance of the battery cell 10.

[0138] In some embodiments, please refer to Figure 8 , the head end and the tail end of the first insulating film 2 at least partially overlap to form a first overlapping area B1.

[0139] When the number of the first insulating films 2 is one, the head end and the tail end of the first insulating film 2 at least partially overlap, so as to form a first overlapping area B1; when the number of the first insulating films 2 is multiple, the head end of one of the adjacent two first insulating films 2 overlaps with the tail end of the other, so as to form a first overlapping area B1. It should be noted that when the number of the first insulating films 2 is multiple, any two first insulating films 2 can form a first overlapping area B1, that is, the number of the first overlapping areas B1 can be one or multiple, and the embodiments of the present application do not limit this.

[0140] The thickness of the first insulating film 2 at the first overlapping area B1 is the sum of the thicknesses of the head end and the tail end of the first insulating film 2. Therefore, compared with other areas of the first insulating film 2, the thickness of the first insulating film 2 at the first overlapping area B1 is greater. The embodiments of the present application do not limit the thickness and other dimensions of the first overlapping area B1.

[0141] At the position of the first overlapping area B1, in addition to being attached and fixed to the first part 11, the first insulating film 2 can also be attached and fixed to the first insulating film 2 itself. Therefore, at the first overlapping area B1, the first insulating film 2 can play a dual fixing role, thereby improving the attachment effect between the first insulating film 2 and the first part 11.

[0142] In the embodiment of the present application, by at least partially overlapping the head end and the tail end of the first insulating film 2, a first overlapping region B1 is formed. The existence of the first overlapping region B1 can improve the fitting effect of the first insulating film 2 at the first part 11. At the same time, since the first insulating film 2 has a double-layer structure in the first overlapping region B1, the insulating effect of the battery cell at the position of the first overlapping region B1 can be improved, and the risk of leakage can be reduced.

[0143] In some embodiments, such as Figure 4 , Figure 5 and Figure 8 shown, the first part 11 has a first side surface 111 in the second direction Y and a first bottom surface 112 in the third direction Z. The size of the first side surface 111 in the third direction Z is smaller than the size of the first bottom surface 112 in the second direction Y. The first direction X, the second direction Y, and the third direction Z intersect pairwise. Among them, the first overlapping region B1 is located on the first side surface 111 or the first bottom surface 112.

[0144] The first direction X, the second direction Y, and the third direction Z are respectively one of the length direction, the width direction, and the height direction of the battery cell 10. Exemplarily, the first direction X, the second direction Y, and the third direction Z are perpendicular to each other pairwise.

[0145] The first side surface 111 and the first bottom surface 112 are respectively two surfaces of the first part 11, and the first side surface 111 can be connected to the first bottom surface 112. The first side surface 111 extends and is formed along the first direction X and the third direction Z respectively, and the first bottom surface 112 extends and is formed along the first direction X and the second direction Y respectively. Usually, the sizes of the first side surface 111 and the first bottom surface 112 in the first direction X are the same. Therefore, the size of the first side surface 111 in the third direction Z is smaller than the size of the first bottom surface 112 in the second direction Y, which indicates that the area size of the first bottom surface 112 is larger than the area size of the first side surface 111.

[0146] In the embodiment of the present application, the first overlapping region B1 is located on the first side surface 111 or the first bottom surface 112, that is, the entire first overlapping region B1 can be located in the same plane. Compared with the solution where the first overlapping region B1 is located on multiple different planes at the same time, the first overlapping region B1 being located on the first side surface 111 or the first bottom surface 112 can make the head end and the tail end of the first insulating film 2 better fit and be fixed, so that the first insulating film 2 can be relatively flat at the first overlapping region B1, thereby reducing the risk of fitting failure at the first overlapping region B1.

[0147] In some optional embodiments, the first part 11 also has a second side surface 113 opposite to the first side surface 111 in the second direction Y, and also has a second bottom surface 114 opposite to the first bottom surface 112 in the third direction Z. The annular structure formed by a single or multiple first insulating films 2 can completely cover the first side surface 111, the second side surface 113, the first bottom surface 112 and the second bottom surface 114.

[0148] Further, optionally, as Figure 8 As shown, there are two first insulating films 2, one of which is wrapped from the side of the first bottom surface 112 away from the second bottom surface 114 toward the second bottom surface 114, and the other first insulating film 2 is wrapped from the side of the second bottom surface 114 away from the first bottom surface 112 toward the first bottom surface 112, and finally the two first insulating films 2 form a first overlapping area at the first bottom surface 112 or the first side surface.

[0149] In some embodiments, as Figure 5 and Figure 8 As shown, the first overlapping area B1 is located on the first side surface 111 , the size of the first overlapping area B1 in the third direction Z is L1 , the size of the first side surface 111 in the third direction Z is D1 , and L1 and D1 satisfy: 2mm≤L1≤D1.

[0150] The first overlapping region B1 is located on the first side surface 111 and extends along both the first direction X and the third direction Z. If the dimensions of the first overlapping region B1 in the third direction Z are too small, the bonding between the leading and trailing ends of the first insulating film 2 cannot be guaranteed, and the leading and trailing ends may separate. Furthermore, since the first overlapping region B1 is located on the first side surface 111, the dimensions of the first overlapping region B1 must be within the dimensions of the first side surface 111.

[0151] In summary, in this embodiment of the present application, the dimension L1 of the first overlapping region B1 in the third direction Z is set to no less than 2 mm. This ensures that the leading and trailing ends of the first insulating film 2 have a first overlapping region B1 of a certain size, reducing the risk of separation between the leading and trailing ends. Furthermore, this embodiment of the present application also sets L1 to no greater than D1 to ensure that the first overlapping region B1 is completely located on the first side surface 111, meeting actual production requirements. For example, L1 is one of 2 mm, 3 mm, 4 mm, and 6 mm.

[0152] In some embodiments, see Figure 11 and Figure 12 The first overlapping area B1 is located on the first bottom surface 112 , the size of the first overlapping area B1 in the second direction Y is L2 , the size of the first bottom surface 112 in the second direction Y is D2 , and L2 and D2 satisfy: 4mm≤L2≤D2.

[0153] The first overlapping region B1 is located on the first bottom surface 112. The first overlapping region B1 extends along the first direction X and the second direction Y respectively. At this time, if the dimension of the first overlapping region B1 in the second direction Y is too small, the fitting effect between the head end and the tail end in the first insulating film 2 cannot be guaranteed, and there is an easy risk of separation between the head end and the tail end. At the same time, since the area dimension of the first bottom surface 112 is larger than the area dimension of the first side surface 111, the first overlapping region B1 located on the first bottom surface 112 can be allowed to have a larger dimension. In addition, since the first overlapping region B1 is located on the first bottom surface 112, the dimension of the first overlapping region B1 needs to be within the dimension range of the first bottom surface 112.

[0154] In summary, in the embodiment of the present application, the dimension of the first overlapping region B1 in the second direction Y, i.e., L2, is set to be not less than 4 mm, so as to ensure that the head end and the tail end of the first insulating film 2 can have a first overlapping region B1 with a certain dimension, reducing the risk of separation between the head end and the tail end. At the same time, in the embodiment of the present application, L2 is also set to be not greater than D2 to ensure that the first overlapping region B1 can be completely located on the first bottom surface 112, meeting the actual production requirements. Exemplarily, L2 is one of 4 mm, 6 mm, 8 mm, and 10 mm.

[0155] In some embodiments, please refer to Figure 5 and Figures 9 to 12 , the battery cell 10 further includes an electrode assembly 4 disposed in the housing 1. The electrode assembly 4 includes a main body portion 41 and a tab portion 42 that are connected to each other. The main body portion 41 has a first surface 411 and a second surface 412 that are connected to each other. The first surface 411 is disposed opposite to the first bottom surface 112 in the third direction Z, and the second surface 412 is disposed opposite to the first side surface 111 in the second direction Y. The dimension of the second surface 412 in the third direction Z is smaller than the dimension of the first surface 411 in the second direction Y. Among them, the first overlapping region B1 is located on the first bottom surface 112, and the orthographic projection of the first surface 411 on the first bottom surface 112 and the orthographic projection of the first overlapping region B1 on the first bottom surface 112 are misaligned.

[0156] The electrode assembly 4 is the main component for realizing the power supply function inside the battery cell 10. The electrode assembly 4 includes a main body portion 41 and a tab portion 42. The main body portion 41 can be the part of the electrode assembly 4 where the active material layer is provided, and the tab portion 42 can be the part of the electrode assembly 4 where the active material layer is not provided. The tab portion 42 can be located only on one side of the main body portion 41 or on both sides of the main body portion 41.

[0157] The main body portion 41 includes a first surface 411 and a second surface 412, and the first surface 411 and the second surface 412 intersect. The first surface 411 is disposed opposite to the first bottom surface 112, and optionally, the first surface 411 is parallel to the first bottom surface 112. The second surface 412 is disposed opposite to the first side surface 111, and optionally, the second surface 412 is parallel to the first side surface 111. The first surface 411 extends and is formed along the first direction X and the second direction Y respectively, and the second surface 412 extends and is formed along the first direction X and the third direction Z respectively. Usually, the dimensions of the first surface 411 in the first direction X are the same. Therefore, the dimension of the second surface 412 in the third direction Z is smaller than the dimension of the first surface 411 in the second direction Y, which indicates that the area dimension of the second surface 412 is larger than the area dimension of the first surface 411.

[0158] As can be seen from the foregoing, the thickness of the first overlapping region B1 will be greater than the thickness at other positions of the first insulating film 2. Therefore, a stepped structure will be formed at the junction of the first overlapping region and other structures. If the orthographic projection of the first overlapping region B1 on the first bottom surface 112 overlaps with the orthographic projection of the first surface 411 on the first bottom surface 112, then at the stepped structure, the electrode assembly 4 is prone to uneven force and safety hazards will occur.

[0159] Specifically, during the use of the battery cell 10, due to the influence of factors such as temperature, the main body portion 41 in the electrode assembly 4 will expand, resulting in an overall increase in the size of the main body portion 41. Especially on the surface with a larger size of the main body portion 41, that is, at the first surface 411, the electrode assembly 4 is prone to bulging.

[0160] In the case of battery expansion, the first surface 411 of the main body portion 41 will come into contact with the outer shell 1, and the acting force will be transmitted to the first insulating film 2 through the outer shell 1. The first insulating film 2 and the outer shell 1 will apply a certain reaction force to the main body portion 41 to inhibit the excessive expansion of the main body portion 41. If the orthographic projection of the first overlapping region B1 on the first bottom surface 112 overlaps with the orthographic projection of the first surface 411 on the first bottom surface 112, then on both sides of the stepped structure, due to the different thicknesses, the magnitudes of the acting forces applied to the main body portion 41 are not the same, which further leads to uneven force on the main body portion 41, thus affecting the normal operation of the electrode assembly 4 and easily causing certain safety hazards.

[0161] In the embodiments of the present application, in order to avoid the problem of uneven stress on the electrode assembly 4 caused by the difference in thickness at the position of the first overlapping region B1 and the thickness at other positions on the first insulating film 2, the positive projection of the first surface 411 on the first bottom surface 112 and the positive projection of the first overlapping region B1 on the first bottom surface 112 are arranged in a staggered manner, that is, the thickness of the first insulating film 2 at the position corresponding to the first surface 411 is kept consistent, thereby improving the service reliability of the battery cell 10. Optionally, the positive projection of the first overlapping region B1 on the first bottom surface 112 is located on at least one side of the positive projection of the first surface 411 on the first bottom surface 112 along the second direction Y.

[0162] In some embodiments, please refer to Figure 13 , Figure 14 , Figure 15 , the second part 12 is located on at least one side of the first part 11 along the first direction X. The second part 12 has opposite first surface 121 and second surface 122 in the third direction Z. The concave portion A1 is recessed inward from the second surface 122 toward the direction close to the first surface 121. The second insulating film 3 includes a first sub-portion 31 covering the first surface 121 and a second sub-portion 32 covering the second surface 122.

[0163] The second part 12 is located on at least one side of the first part 11 along the first direction X. Exemplarily, when the number of the second parts 12 is two, the two second parts 12 are located on both sides of the first part 11 along the first direction X.

[0164] The second part 12 has opposite first surface 121 and second surface 122, and the concave portion A1 is located on the second surface 122. The specific position of the concave portion A1 on the second surface 122 is not limited in the embodiments of the present application.

[0165] Due to the existence of the concave portion A1, the first surface 121 and the second surface 122 are not the same, and the first surface 121 is flatter than the second surface 122. Therefore, the embodiments of the present application set the second part 12 to include at least two parts, namely a first sub-portion 31 and a second sub-portion 32. The first sub-portion 31 is adjusted according to the shape profile of the first surface 121 and is arranged in a fitting manner with the first surface 121; the second sub-portion 32 is adjusted according to the shape profiles of the second surface 122 and the concave portion A1, so as to better cover the second surface 122 and the concave portion A1.

[0166] In the embodiment of the present application, according to the structure of the second part 12, the second insulating film 3 is provided with a first sub - part 31 and a second sub - part 32. The first sub - part 31 covers the first surface 121, and the second sub - part 32 covers the second surface 122. By adjusting the shape and size of the first sub - part 31 and the second sub - part 32, the second insulating film 3 can better cover the second part 12, thereby improving the insulation effect of the battery cell 10 at the second part 12 and enhancing the safety of the battery cell 10.

[0167] In some embodiments, referring to Figure 13 and Figure 15 , the second sub - part 32 includes a first segment 321, and a second segment 322 and a third segment 323 located on both sides of the first segment 321 along the second direction Y. At least one of the second segment 322 and the third segment 323 is partially overlapped with the first segment 321 to form a second overlapping region B2.

[0168] The first segment 321, the second segment 322, and the third segment 323 are arranged side by side in the second direction Y. The second segment 322 and the third segment 323 are respectively located on both sides of the first segment 321. The first segment 321 is used to cover the second surface 122 and the central position of the concave portion A1, and the second segment 322 and the third segment 323 are used to cover the second surface 122 and the edge positions of the concave portion A1.

[0169] Regarding the shape and size of the first segment 321, the second segment 322, and the third segment 323, the embodiment of the present application does not make any restrictions. Exemplarily, the second segment 322 and the third segment 323 are symmetrically distributed on both sides of the first segment 321.

[0170] At least one of the second segment 322 and the third segment 323 is partially overlapped with the first segment 321 to form a second overlapping region B2. Compared with the thickness of other regions at the second sub - part 32, the thickness of the second sub - part 32 at the second overlapping region B2 is greater. Among them, at the second overlapping position, it can be that the first segment 321 is attached to the second part 12, or the second segment 322 or the third segment 323 is attached to the second part 12. The embodiment of the present application does not make any restrictions on this.

[0171] At the position of the second overlapping region B2, in addition to being attached to the second part 12, at least one of the third segment 323 and the second segment 322 in the second sub - part 32 is also attached and fixed to the first segment 321. Therefore, at the second overlapping region B2, the second insulating film 3 can play a dual - fixing role, thereby improving the attachment effect between the second insulating film 3 and the second part 12. Optionally, the number of the second overlapping regions B2 is two. In one of the second overlapping regions B2, the first segment 321 and the second segment 322 overlap each other, and in the other second overlapping region B2, the first segment 321 and the third segment 323 overlap each other.

[0172] In the embodiment of the present application, by arranging at least one of the second segment 322 and the third segment 323 to partially overlap with the first segment 321, the second overlapping region B2 is formed. The existence of the second overlapping region B2 can improve the attachment effect of the second insulating film at the second part 12. At the same time, since the second insulating film 3 has a double - layer structure at the second overlapping region B2, the insulation effect of the battery cell 10 at the second overlapping region B2 can be improved, reducing the risk of electric leakage.

[0173] In some embodiments, please refer to Figure 5 、 Figure 9 and Figure 13 , the first surface 411 and the first surface 121 are arranged opposite to each other in the third direction Z. In a plane perpendicular to the third direction Z, the orthographic projection of the first surface 411 and the orthographic projection of the second overlapping region B2 are misaligned.

[0174] The "plane perpendicular to the third direction Z" mentioned in the embodiment of the present application refers to: any virtual plane perpendicular to the third direction Z. The orthographic projection of the first surface 411 in this plane is the projection of the first surface 411 along the third direction Z, and the orthographic projection of the second overlapping region B in this plane is the projection of the second overlapping region B2 along the third direction Z.

[0175] The thickness of the second overlapping region B2 is greater than the thickness of other positions of the second insulating film 3. Therefore, a step structure will be formed at the junction of the second overlapping region and other structures. Similar to the first overlapping region B1, if the orthographic projection of the second overlapping region B2 and the orthographic projection of the first surface 411 overlap, the electrode assembly 4 is likely to be unevenly stressed at the step structure, resulting in potential safety hazards.

[0176] In the embodiments of the present application, in order to avoid the problem of uneven stress on the electrode assembly 4 caused by the different thicknesses between the second overlapping region B2 and other positions on the second insulating film 3, the positive projection of the first surface 411 and the positive projection of the second overlapping region B2 are distributed in a staggered manner in the embodiments of the present application, that is, the thickness of the second insulating film 3 at the position corresponding to the first surface 411 is kept consistent, thereby improving the use reliability of the battery cell 10. Optionally, the positive projection of the second overlapping region B2 is located on at least one side of the positive projection of the first surface 411 along the first direction X.

[0177] In some embodiments, as Figure 13 and Figure 15 shown, the dimension L3 of the second overlapping region B2 in the second direction Y is not greater than 4 mm.

[0178] The second overlapping region B2 is formed by the overlap of at least one of the second segment 322 and the third segment 323 with the first segment 321. If the size of the second overlapping region B2 is too large, interference is likely to occur between the first segment 321, the second segment 322, and the third segment 323, which is not conducive to the fitting of the second insulating film 3.

[0179] Therefore, in the embodiments of the present application, the dimension L3 of the second overlapping region B2 in the second direction Y is set to be not greater than 4 mm, reducing the interference between the first segment 321, the second segment 322, and the third segment 323, and improving the fitting effect of the second insulating film. Exemplarily, L3 is one of 1 mm, 2 mm, 3 mm, and 4 mm.

[0180] In some embodiments, as Figure 15 shown, the second insulating film 3 has an unfolded state. In the unfolded state, the second insulating film 3 is a sheet structure, and the first segment 321, the second segment 322, and the third segment 323 are separated from each other and are all connected to the first sub - part 31.

[0181] The second insulating film 3 has at least two states: an unfolded state and a fitting state. In the unfolded state, the second insulating film 3 is a sheet structure and has not been fitted to the second part 12 yet; in the fitting state, the second insulating film 3 is fitted to the second part 12, and at this time, at least one of the second segment 322 and the third segment 323 overlaps with the first segment 321 to form the second overlapping region B2.

[0182] In order to enable the second insulating film 3 to form the second overlapping region B2 in the attached state, in the embodiments of the present application, the first segment 321, the second segment 322, and the third segment 323 in the unfolded state are separated from each other. During the transition from the unfolded state to the attached state, the second segment 322 and the third segment 323 can be attached in a direction approaching the first segment 321, thereby forming the second overlapping region B2. At the same time, the first segment 321, the second segment 322, and the third segment 323 are all connected to the first sub-part 31. Therefore, the second insulating film 3 in the embodiments of the present application can be obtained by simply cutting a sheet-like structure, and the preparation process is simple and convenient, which is beneficial to large-scale production and manufacturing.

[0183] In some embodiments, such as Figure 14 and Figure 15 shown, the first sub-part 31 includes an avoidance hole 311, and the avoidance hole 311 is used to avoid the protrusion 1221 located on the first surface 121.

[0184] Due to the limitation of the structure of the housing 1, there is a protrusion 1221 on the first surface 121. Exemplarily, the housing 1 includes a hollow structure housing and an end cover for covering the housing. The first surface 121 is located on the end cover, and the protrusion 1221 includes an electrode terminal 5, and the electrode terminal 5 is electrically connected to the pole ear of the electrode assembly. Further, the protrusion 1221 may further include a terminal plate 6 fixed on the housing, the electrode terminal 5 is installed on the terminal plate 6, and the terminal plate 6 can realize the fixation of the electrode terminal 5. Exemplarily, the electrode terminal 5 is riveted to the terminal plate 6.

[0185] In order to avoid the protrusion 1221, the avoidance hole 311 is provided on the first sub-part 31 in the embodiments of the present application. The avoidance hole 311 penetrates through the first sub-part 31, and the protrusion 1221 can completely penetrate through the avoidance hole 311. The existence of the avoidance hole 311 can prevent the second insulating film 3 from being wrinkled and warped due to the protrusion 1221, and improve the attachment effect between the second insulating film 3 and the second part 12.

[0186] In some alternative embodiments, protrusions are also provided on the second surface 122 and the first part 11. At this time, avoidance holes for avoiding the protrusions can also be provided on the first sub-part 31 and the first insulating film 2.

[0187] In some embodiments, such as Figure 13 and Figure 15 shown, the second insulating film 3 and the first insulating film 2 are overlapped to form a third overlapping region B3.

[0188] At the third overlapping region B3, either the first insulating film 2 or the second insulating film 3 can be attached to the housing 1. Also, either the first sub - portion 31 or the second sub - portion 32 in the second insulating film 3 can overlap with the first insulating film 2. In addition, the third overlapping region B3 can be located on the first part 11, or on the second part 12, or even partially on the first part 11 and partially on the second part 12. The embodiments of the present application do not limit the above content.

[0189] At the position of the third overlapping region B3, in addition to the first insulating film 2 or the second insulating film 3 being able to be attached to the housing 1, the first insulating film 2 can also be attached and fixed to the second insulating film 3. Therefore, double fixation can be achieved at the third overlapping region B3, thereby improving the attachment effect among the first insulating film 2, the second insulating film 3, and the housing 1.

[0190] In the embodiments of the present application, by overlapping the second insulating film 3 with the first insulating film 2, the third overlapping region B3 is formed. The existence of the third overlapping region B3 can improve the attachment effect among the first insulating film 2, the second insulating film 3, and the housing 1. At the same time, since the third overlapping region B3 has a double - layer structure, the insulation effect of the battery cell 10 at the third overlapping region B3 can be improved, reducing the risk of electric leakage.

[0191] In some embodiments, the third overlapping region B3 covers the first part 11, that is, the third overlapping region B3 is located at the first part 11 and not at the second part 12.

[0192] In the embodiments of the present application, since the second part 12 is provided with the recess A1, if the third overlapping region B3 is arranged at the second part 12, the existence of the recess A1 may affect the attachment effect between the first insulating film 2 and the second insulating film 3, resulting in the risk of wrinkles or warping. Therefore, to avoid this situation, the embodiments of the present application arrange the third overlapping region B3 at the position of the first part 11 to ensure the flat attachment of the first insulating film 2 and the second insulating film 3.

[0193] In some embodiments, as Figure 13 and Figure 15 shown, the dimension L4 of the third overlapping region B3 in the first direction X is not less than 4 mm.

[0194] The third overlapping region B3 extends along the first direction X and the second direction Y respectively. If the dimension of the third overlapping region B3 in the first direction X is too small, the attachment effect between the first insulating film 2 and the second insulating film 3 will be poor, easily leading to the risk of warping at the third overlapping region B3.

[0195] Therefore, in the embodiments of the present application, the size L4 of the third overlapping region B3 in the first direction X is set to be not less than 4 mm, so as to ensure the fitting effect between the first insulating film 2 and the second insulating film 3 and reduce the risk of warping at the third overlapping region B3. Exemplarily, L4 is one of 4 mm, 6 mm, 8 mm, and 10 mm.

[0196] In some embodiments, referring to Figure 16 , there are two first parts 11, and the two first parts 11 are respectively located on both sides of the second part 12 along the first direction X, and the second insulating film 3 wraps the second part 12 around an axis A2 parallel to the first direction X.

[0197] The "axis A2" mentioned in the embodiments of the present application refers to a virtual straight line parallel to the first direction X. The second insulating film 3 is arranged around the axis A2 and covers the second part 12. Among them, the axis A2 has no direct relationship with the shape and structure of the housing.

[0198] As can be seen from the foregoing, the recess A1 specifically refers to the area on the second part 12 that is recessed inward relative to the first part 11. Due to the existence of the recess A1, the first part 11 will at least partially protrude from the second part 12 in the third direction Z.

[0199] The first parts 11 are respectively located on both sides of the second part 12. When using the second insulating film 3 to wrap the second part 12, it is impossible to semi-surround and wrap the second part 12 from the edge side of the second part 12. Therefore, in the embodiments of the present application, the second insulating film 3 wraps the second part 12 around an axis A2 parallel to the first direction X, so that the second insulating film 3 can cover multiple surfaces of the second part 12 and improve the wrapping effect on the second part 12.

[0200] It should be noted that the embodiments of the present application do not limit the structure of the first insulating film 2 and how to wrap the first insulating film 2 around the first part 11. Exemplarily, the first part 11 has two opposite surfaces in the third direction Z, and the first insulating film 2 includes two parts corresponding to the two surfaces. During the process of the first insulating film 2 fitting with the first part 11, the first insulating film 2 first fits with one surface of the first part 11 in the third direction Z, then winds around to the side of the first part 11 away from the second part 12, and finally fits with the other surface of the first part 11 in the third direction Z.

[0201] In some embodiments, referring to Figure 3 and Figure 12 , the thickness of at least one of the first insulating film 2 and the second insulating film 3 is H, and H satisfies: 0.01 mm ≤ H ≤ 0.5 mm. Exemplarily, H is one of 0.01 mm, 0.02 mm, 0.05 mm, and 0.5 mm.

[0202] It should be noted that the embodiments of the present application include three cases in total. In the first case, only the thickness of the first insulating film 2 meets the limitation of 0.01 mm ≤ H ≤ 0.5 mm. In the second case, only the thickness of the second insulating film 3 meets the limitation of 0.01 mm ≤ H ≤ 0.5 mm. In the third case, while the thickness of the first insulating film 2 meets the limitation of 0.01 mm ≤ H ≤ 0.5 mm, the thickness of the second insulating film 3 also meets the limitation of 0.01 mm ≤ H ≤ 0.5 mm.

[0203] If the first insulating film 2 or the second insulating film 3 is too thin, it is likely to result in poor insulation effect of the housing 1. If the first insulating film 2 or the second insulating film 3 is too thick, it will cause the overall size of the battery cell to become larger, and then lead to a decrease in the energy density of the battery cell, unable to meet the requirement of being lightweight.

[0204] Therefore, the embodiments of the present application limit the thickness of at least one of the first insulating film 2 and the second insulating film 3 to avoid being too thick or too thin. While ensuring the insulation effect of the housing 1, the energy density of the battery cell is improved to meet the actual use requirements. Optionally, 0.1 mm ≤ H ≤ 0.2 mm. Exemplarily, H is one of 0.1 mm, 0.15 mm, 0.18 mm, and 0.2 mm.

[0205] In a second aspect, please refer to Figure 2 and Figure 17 , the embodiments of the present application provide a battery, including the battery cell 10 in any of the foregoing embodiments. A plurality of battery cells 10 are arranged side by side in the thickness direction of the battery cell 10, and the recess A1 is used to accommodate the electrode terminals of the battery cell 10 adjacent to the recess.

[0206] Combined with the figure and the foregoing content, it can be seen that the recess A1 can be provided on the second surface 122, and the electrode terminals (not shown in the figure) can protrude from the first surface 121. The first surface 121 and the second surface 122 are oppositely arranged in the third direction Z, and the third direction Z is the thickness direction of the battery cell 10. Optionally, the recess A1 can also be used to accommodate the terminal plate 6 of the battery cell 10 adjacent to the recess.

[0207] On this basis, the embodiments of the present application arrange a plurality of battery cells 10 side by side in the thickness direction of the battery cell 10, so that the electrode terminals can be located in the recesses of adjacent battery cells 10, thereby improving the space utilization rate.

[0208] It should be noted that the battery provided by the embodiments of the present application has the beneficial effects of the battery cell 10 in any of the foregoing embodiments. For specific reference, please refer to the description of the battery cell 10 above, and the embodiments of the present application will not be repeated here.

[0209] In a third aspect, an embodiment of the present application provides an electrical device, including the battery cell in any of the foregoing embodiments, and the battery cell is used to provide electrical energy.

[0210] It should be noted that the electrical device provided by the embodiment of the present application has the beneficial effects of the battery cell in any of the foregoing embodiments. For specific details, please refer to the description of the battery cell above, and the embodiments of the present application will not be elaborated herein.

[0211] In a fourth aspect, please refer to Figures 18 to 21 , an embodiment of the present application provides a method for preparing a battery cell, including:

[0212] S100: Provide a housing, the housing includes a first part and a second part arranged side by side, and a recess is provided on the second part.

[0213] Please refer to , in step S100, a recess A1 is provided on the second part 12, and the recess A1 specifically refers to a region on the second part 12 that is recessed inward relative to the first part 11. The existence of the recess A1 causes the overall surface of the housing 1 to be no longer flat. At this time, if an insulating film is used to cover the entire housing 1, since the overall surface of the housing 1 is no longer flat, the insulating film cannot completely cover the housing 1, resulting in a leakage problem.

[0214] S110: Provide a first insulating film and wrap the first insulating film around the first part.

[0215] Please refer to Figure 19 , in step S110, the first insulating film 2 is specifically designed according to the outer contour of the first part 11, so as to improve the wrapping effect on the first part 11.

[0216] S120: Provide a second insulating film and wrap the second insulating film around the second part.

[0217] Please refer to Figure 20 , in step S120, the second insulating film 3 is specifically designed according to the outer contour of the second part 12, and can better cover the recess A1, so as to improve the wrapping effect on the second part 12.

[0218] The preparation method provided by the embodiment of the present application can better wrap the housing 1 of the battery cell 10 compared with the prior art, thereby improving the overall insulation performance of the housing 1, reducing the risk of leakage of the battery cell, and improving the use safety of the battery cell.

[0219] In some embodiments, in step S110, it includes: surrounding the first insulating film 2 around the first part 11 to form a ring structure.

[0220] The first insulating film 2 forms an annular structure surrounding the first part 11, and the first insulating film 2 has various coating methods. Exemplarily, as Figure 21 and Figure 6 shown, the first part 11 includes a first bottom surface 112 and a first side surface 111 that are connected to each other and intersect. The area of the first bottom surface 112 is larger than that of the first side surface 111. The number of the first insulating films 2 is one, and a single first insulating film 2 forms an annular structure and forms an annular structure at the position of the first side surface 111.

[0221] Alternatively, as Figure 7 shown, the first part 11 further includes a second bottom surface 114 opposite to the first bottom surface 112. The number of the first insulating films 2 is two. One is located on the side of the first bottom surface 112 away from the second bottom surface 114 and coats in the direction close to the second bottom surface 114; the other is located on the side of the second bottom surface 114 away from the first bottom surface 112 and coats in the direction close to the first bottom surface 112, and the two can overlap at the position of the first side surface or the first bottom surface 112.

[0222] In the embodiment of the present application, by surrounding the first insulating film 2 to form an annular structure, the first insulating film 2 can better cover the first part 11, thereby improving the insulation effect at the position of the first part 11.

[0223] In some embodiments, please refer to Figure 7 , the second part 12 is located on at least one side of the first part 11 along the first direction X. The second part 12 has opposite first surface 121 and second surface 122 in the third direction Z. The recess A1 is formed by inwardly recessing from the second surface 122 towards the first surface 121. The first direction X intersects with the second direction Y.

[0224] The second insulating film 3 includes a first sub - part 31 and a second sub - part 32 that are connected to each other. In step S120, it includes:

[0225] S121: Cut the second sub - part so that the second sub - part forms a first segment and second segments and third segments located on both sides of the first segment. The first segment, the second segments, and the third segments are separated from each other and are all connected to the first sub - part.

[0226] Please refer to Figures 22 to 25, in step S121, the second insulating film 3 is in a sheet structure and has not been attached to the second part 12 yet. Due to the existence of the recess A1, if the second sub - part 32 is an integral structure, then during the process of the second sub - part 32 attaching and covering the recess A1, the second sub - part 32 will have wrinkling phenomena, resulting in poor attachment between the second sub - part 32 and the recess A1. To avoid this phenomenon, in the embodiment of the present application, the first segment 321, the second segment 322, and the third segment 323 are separated from each other, so that the first segment 321, the second segment 322, and the third segment 323 can be attached to the recess A1 respectively, thereby reducing or avoiding the appearance of wrinkles.

[0227] S122: Attach the first sub - part to the first surface.

[0228] Please refer to Figure 23 , in step S122, during the process of the second insulating film 3 covering the second part 12, since the first surface 121 is relatively flat, the first sub - part 31 is first attached to the first surface 121 to achieve the preliminary positioning between the second insulating film 3 and the second part 12.

[0229] S123: Attach the first segment, the second segment, and the third segment to the second surface, so that the first segment, the second segment, and the third segment jointly cover the second surface.

[0230] Please refer to Figure 24 , in step S123, the first segment 321 is attached to the central position of the second surface 122 and the recess A1, and the second segment 322 and the third segment 323 are respectively attached to the edge positions of the second surface 122 and the recess A1. Among them, for the attachment sequence of the first segment 321, the second segment 322, and the third segment 323, the embodiment of the present application does not make any restrictions. Exemplarily, the first segment 321 is attached first, and then the second segment 322 and the third segment 323 can be attached simultaneously.

[0231] In the embodiment of the present application, by separating the first segment 321, the second segment 322, and the third segment 323 from each other, the first segment 321, the second segment 322, and the third segment 323 can be attached to the recess A1 respectively, thereby reducing or avoiding the appearance of wrinkles. Thus, the attachment effect of the second insulating film 3 can be improved, and the insulation performance of the second part 12 can be enhanced.

[0232] According to some embodiments of the present application, please refer to Figure 25 、 Figure 3 、 Figure 5 、 Figure 7 、 Figure 8 、 Figure 9 、 Figure 12 and Figure 13 Figure 15, the battery includes a housing 1, a first insulating film 2, a second insulating film 3, and a battery cell 10. The housing 1 includes a first part 11 and a second part 12 arranged side by side in the first direction X, and the second part 12 is provided with a recess A1. The number of the first insulating films 2 is multiple, and the multiple first insulating films 2 are sequentially connected end to end to form an annular structure surrounding the first part 11, and the head and tail ends of the first insulating film 2 at least partially overlap to form a first overlapping region B1. The first part 11 has a first side surface 111 in the second direction Y and a first bottom surface 112 in the third direction Z, and the first overlapping region B1 is located on the first side surface 111 or the first bottom surface 112.

[0233] The second part 12 has opposite first surface 121 and second surface 122 in the third direction Z, and the recess A1 is formed by inward depression from the second surface 122 to the first surface 121. The second insulating film 3 includes a sub-part covering the first surface 121 and a second sub-part 32 covering the second surface 122. The second sub-part 32 includes a first segment 321, and a second segment 322 and a third segment 323 located on both sides of the first segment 321 in the second direction Y. At least one of the second segment 322 and the third segment 323 is arranged to partially overlap with the first segment 321 to form a second overlapping region B2. And the first insulating film 2 and the second insulating film 3 are at least partially overlapped to form a third overlapping region B3.

[0234] The electrode assembly 4 is located inside the housing 1. The electrode assembly 4 includes a main body part 41 and a tab part 42 connected to each other. The main body part 41 has a first surface 411 and a second surface 412 connected to each other. The first surface 411 is arranged opposite to the first side surface 111 in the second direction Y, and the second surface 412 is arranged opposite to the first bottom surface 112 in the third direction Z. In a plane perpendicular to the third direction Z, the orthographic projection of the first surface 411 is misaligned with the orthographic projection of the first overlapping region B1, and the orthographic projection of the first surface 411 is misaligned with the orthographic projection of the second overlapping region B2.

[0235] It should be noted that, without conflict, the embodiments and features in the embodiments of the present application can be combined with each other.

[0236] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting 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 recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features, but these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A battery cell, characterized in that, Comprising: A housing, the housing including a first part and a second part arranged side by side, and a recess is provided on the second part; A first insulating film, covering the first part; A second insulating film, covering the second part; The second part is located on at least one side of the first part in a first direction, the second part has a first surface and a second surface opposite to each other in a third direction, and the recess is formed by inwardly recessing from the second surface towards the first surface; The second insulating film includes a first sub-part covering the first surface and a second sub-part covering the second surface; The second sub-part includes a first segment and a second segment and a third segment located on both sides of the first segment in a second direction, and at least one of the second segment and the third segment is arranged to partially overlap with the first segment to form a second overlapping area, and the first direction, the second direction, and the third direction intersect pairwise.

2. The battery cell according to claim 1, characterized in that, The first part and the second part are arranged side by side in the first direction, and the first direction is the length direction of the battery cell.

3. The battery cell according to claim 1, wherein A flanging structure is provided at the edge of the housing, and the flanging structure at least partially surrounds the first part; The first insulating film covers part of the flanging structure.

4. The battery cell according to claim 3, characterized in that, The first part and the second part are arranged side by side in the first direction, the flanging structure is located on at least one side of the first part in the second direction, and the first direction intersects with the second direction.

5. The battery cell according to claim 1, characterized in that, The first part and the second part are arranged side by side in the first direction, and the first insulating film covers the first part around an axis parallel to the first direction.

6. The battery cell according to claim 5, characterized in that, A single first insulating film forms an annular structure surrounding the first part.

7. The battery cell according to claim 5, wherein The number of the first insulating films is multiple, and the multiple first insulating films are connected end to end in sequence to form an annular structure surrounding the first part.

8. The battery cell according to any one of claims 5-7, characterized in that, The head end and the tail end of the first insulating film at least partially overlap to form a first overlapping area.

9. The battery cell according to claim 8, characterized in that, The number of the first overlapping areas is multiple.

10. The battery cell according to claim 8, characterized in that, A flanging structure is provided at the edge of the housing; The first insulating film covers part of the flanging structure, and the first overlapping area is arranged to avoid the flanging structure.

11. The battery cell according to claim 8, wherein, The first part has a first side surface in the second direction and a first bottom surface in the third direction, the size of the first side surface in the third direction is smaller than the size of the first bottom surface in the second direction, and the first direction, the second direction, and the third direction intersect pairwise; Wherein, the first overlapping area is located on the first side surface or the first bottom surface.

12. The battery cell according to claim 11, characterized in that, The first overlapping area is located on the first side surface, the size of the first overlapping area in the third direction is L1, the size of the first side surface in the third direction is D1, and L1 and D1 satisfy: 2mm ≤ L1 ≤ D1.

13. The battery cell according to claim 12, characterized in that, The first overlapping area is located on the first bottom surface, the size of the first overlapping area in the second direction is L2, the size of the first bottom surface in the second direction is D2, and L2 and D2 satisfy: 4mm ≤ L2 ≤ D2.

14. The battery cell according to claim 11, characterized in that It further includes an electrode assembly disposed within the housing. The electrode assembly includes a main body portion and a tab portion that are interconnected. The main body portion has a first surface and a second surface that are interconnected. The first surface is disposed opposite to the first bottom surface in the third direction. The second surface is disposed opposite to the first side surface in the second direction. The dimension of the second surface in the third direction is smaller than the dimension of the first surface in the second direction. Wherein, the first overlapping region is located on the first bottom surface, and the orthographic projection of the first surface on the first bottom surface and the orthographic projection of the first overlapping region on the first bottom surface are staggeredly distributed.

15. The battery cell according to claim 14, wherein The orthographic projection of the first overlapping region on the first bottom surface is located on at least one side of the orthographic projection of the first surface on the first bottom surface along the second direction.

16. The battery cell according to any one of claims 1-7, characterized in that, The first insulating film covers at least part of the structure of the second portion.

17. The battery cell according to claim 1, characterized in that, It further includes an electrode assembly disposed within the housing. The electrode assembly includes a main body portion and a tab portion that are interconnected. The main body portion has a first surface and a second surface that are interconnected and intersect. The first surface is disposed opposite to the first surface in the third direction. The dimension of the second surface in the third direction is smaller than the dimension of the first surface in the second direction. Wherein, in a plane perpendicular to the third direction, the orthographic projection of the first surface and the orthographic projection of the second overlapping region are staggeredly distributed.

18. The battery cell according to claim 1, characterized in that, The dimension L3 of the second overlapping region in the second direction is not greater than 4 mm.

19. The battery cell according to claim 1, characterized in that, The second insulating film has an unfolded state. In the unfolded state, the second insulating film is a sheet-like structure, and the first segment, the second segment, and the third segment are separated from each other and are all connected to the first sub-portion.

20. The battery cell according to claim 11, wherein The first sub-portion includes an avoidance hole for avoiding a protrusion located on the first surface.

21. The battery cell according to any one of claims 1-7, characterized in that, The second insulating film overlaps with at least part of the first insulating film to form a third overlapping region.

22. The battery cell according to claim 21, characterized in that, The third overlapping region is located in the first portion.

23. The battery cell according to claim 21, wherein, The dimension L4 of the third overlapping region in the first direction is not less than 4 mm.

24. The battery cell according to any one of claims 1-7, characterized in that, There are two first portions, and the two first portions are respectively located on both sides of the second portion along the first direction. The second insulating film wraps around the second portion along an axis parallel to the first direction.

25. The battery cell according to any one of claims 1 to 7, characterized in that, A flanging structure is provided at the edge of the housing, and the flanging structure at least partially surrounds the second portion. The second insulating film wraps around part of the flanging structure.

26. The battery cell according to claim 25, wherein The first portion and the second portion are arranged side by side along the first direction, and the flanging structure is located on the side of the second portion away from the first portion along the first direction.

27. The battery cell according to any one of claims 1-7, characterized in that, The thickness of at least one of the first insulating film and the second insulating film is H, and H satisfies: 0.01 mm ≤ H ≤ 0.5 mm.

28. The battery cell according to claim 27, wherein, 0.1 mm ≤ H ≤ 0.2 mm.

29. A battery, characterized in that, It includes a plurality of battery cells as described in any one of claims 1-28. The plurality of battery cells are arranged side by side along the thickness direction of the battery cell, and the recess is used to accommodate the electrode terminals of the battery cell adjacent to the recess.

30. An electrical device, characterized in that, Comprising a battery cell as described in any one of claims 1-28, the battery cell being used to provide electrical energy.

31. A method for preparing a battery cell, characterized in that, Comprising: Providing a housing, the housing including a first part and a second part arranged side by side, a recess being provided on the second part, the second part being located on at least one side of the first part in a first direction, the second part having a first surface and a second surface opposite to each other in a third direction, the recess being formed by inwardly recessing from the second surface towards the first surface, the first direction intersecting the third direction; Providing a first insulating film and covering the first part with the first insulating film; Providing a second insulating film and covering the second part with the second insulating film; The second insulating film includes a first sub-part and a second sub-part connected to each other. The step of providing the second insulating film and covering the second part with the second insulating film includes: Cutting the second sub-part so that the second sub-part forms a first segment and second and third segments located on both sides of the first segment, the first segment, the second segment and the third segment being separated from each other and all connected to the first sub-part; Attaching the first sub-part to the first surface; Attaching the first segment, the second segment and the third segment to the second surface so that the first segment, the second segment and the third segment jointly cover the second surface.

32. The preparation method according to claim 31, characterized in that, The step of providing the first insulating film and covering the first part with the first insulating film includes: surrounding the first part with the first insulating film to form an annular structure.

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