Battery monomer, battery and electric equipment

Abstract

The utility model discloses a battery monomer, a battery and electric equipment. The battery monomer comprises a shell, an electrode assembly and an insulating film, the housing includes a first wall. The first wall includes a first portion and a second portion. And the first part and the second part are spliced to form a splicing part. The electrode assembly is disposed within the housing. The insulating film is accommodated in the housing and covers at least part of the electrode assembly. The insulating film includes a side wall opposite the first wall. The side wall is provided with a concave part which is concave away from the splicing part, and the concave part and the splicing part are oppositely arranged. The arrangement of the concave part can increase the distance between the insulating film and the splicing part, so that the probability of interference between the splicing part at the joint of the first part and the second part and the insulating film can be reduced, the risk of breakage of the insulating film is reduced, and the reliability of the battery monomer is improved.

Description

Technical Field

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

[0002] The battery cell includes a housing and an insulating film disposed inside the housing. In the related art, the housing of the battery cell is formed by splicing two parts. However, the thickness of the splicing part is usually large, which is likely to interfere with the insulating film, resulting in the rupture of the insulating film and reducing the reliability of the battery cell. Summary of the Utility Model

[0003] The present application provides a battery cell, a battery, and an electrical device, which can solve the problem that when the housing of the battery cell is formed by splicing two parts, the thickness of the splicing part is large, which is likely to interfere with the insulating film, resulting in the rupture of the insulating film.

[0004] The battery cell according to an embodiment of the present application includes a housing, an electrode assembly, and an insulating film. The housing includes a first wall. The first wall includes a first part and a second part. The first part and the second part are spliced and form a splicing part. The electrode assembly is disposed inside the housing. The insulating film is received inside the housing and covers at least part of the electrode assembly. The insulating film includes a side wall opposite to the first wall. The side wall is provided with a recess recessed away from the splicing part, and the recess is disposed opposite to the splicing part.

[0005] In the battery cell according to the embodiment of the present application, the provision of the recess can increase the distance between the insulating film and the splicing part, thereby reducing the probability of interference between the splicing part at the connection of the first part and the second part and the insulating film, and reducing the risk of rupture of the insulating film, and improving the reliability of the battery cell.

[0006] In addition, since the insulating film covers at least part of the electrode assembly, the insulating film can isolate the electrode assembly and the housing to provide an insulating function, thereby reducing the probability of short circuit or other electrical failures of the battery cell.

[0007] In addition, the housing is formed by splicing two parts, which simplifies the manufacturing process of the battery cell and makes it more convenient to assemble the electrode assembly and the insulating film.

[0008] In some embodiments, the first part and the second part are welded to form the splicing part. The battery cell includes a welding auxiliary member disposed on the inner surface of the first wall and connected to the splicing part.

[0009] The welding auxiliary helps to reduce defects that may occur during the welding process, such as porosity, cracks, or incomplete penetration, etc., and improve the welding yield. However, the welding auxiliary has a certain thickness and is prone to interference with the insulating film. Therefore, setting the welding auxiliary at the splicing location can be opposite to the recessed portion, thereby reducing the probability of interference between the welding auxiliary and the insulating film, reducing the risk of rupture of the insulating film, and improving the reliability of the battery cell.

[0010] In some embodiments, along the arrangement direction of the first part and the second part, the length of the recessed portion is greater than the length of the welding auxiliary.

[0011] In this way, by making the length of the recessed portion greater than the length of the welding auxiliary, a wider protection area can be provided for the insulating film, and the longer recessed portion helps to further reduce the probability of interference between the welding auxiliary and the insulating film.

[0012] In some embodiments, the electrode assembly includes a first electrode assembly and a second electrode assembly connected to the first electrode assembly. Both the first electrode assembly and the second electrode assembly are disposed within the housing, and a gap is formed between the first electrode assembly and the second electrode assembly. A protruding portion is formed on one side of the side wall of the insulating film facing the electrode assembly. The protruding portion is disposed opposite to the recessed portion, and at least a part of the protruding portion is located within the gap.

[0013] In this way, the gap can provide a larger space for the protruding portion and the recessed portion, so that the distances between the protruding portion and the recessed portion and the splicing portion are greater, thereby further reducing the probability of interference between the splicing portion and the insulating film.

[0014] In some embodiments, the first electrode assembly includes a first straight portion and a first bent portion connected to the first straight portion. The second electrode assembly includes a second straight portion and a second bent portion connected to the second straight portion. The gap is formed between the first bent portion and the second bent portion.

[0015] In this way, the gap is formed by the inherent structure of the electrode assembly without the need to additionally form structures such as holes or grooves on the first electrode assembly or the second electrode assembly, which maintains the integrity of the electrode assembly, improves the manufacturing efficiency, and reduces the manufacturing cost.

[0016] In some embodiments, the insulating film includes a bottom wall. The side wall is connected to the bottom wall. An avoidance groove is provided at a portion of the bottom wall opposite to the splicing portion.

[0017] In this way, the setting of the avoidance groove can reduce the probability of interference between the splicing portion and the insulating film, thereby reducing the risk of rupture of the insulating film and improving the reliability of the battery cell.

[0018] In some embodiments, the housing includes an end cap and a shell body connected to the end cap. The shell body is provided with an opening. The end cap seals the opening. The battery cell further includes an insulating member disposed on a side of the end cap facing the electrode assembly. The insulating member includes a side surface opposite to the side wall, and a groove is formed in the side surface. The recess is at least partially disposed in the groove.

[0019] In this way, the setting of the groove can match the shape and structure of the recess, thereby reducing the probability of interference between the insulating member and the insulating film, reducing the risk of rupture of the insulating film, and improving the reliability of the battery cell.

[0020] In some embodiments, the side wall is connected to the side surface to form a connecting portion. The connecting portion is at least partially disposed in the recess.

[0021] In this way, there is a relatively large distance between the connecting portion and the first wall, which can reduce the probability of interference between the connecting portion and the first wall or the splicing portion, thereby reducing the risk of rupture of the insulating film and improving the reliability of the battery cell.

[0022] In some embodiments, the housing further includes a second wall connected to the first wall. The area of the second wall is larger than the area of the first wall.

[0023] In this way, since the splicing portion is disposed on the first wall with a relatively small area, this reduces the occupation of the effective internal space of the battery cell by the splicing portion, can adapt to the layout of the electrode assembly and the insulating film, and thus helps the setting of the recess.

[0024] The battery according to the embodiment of the present application includes the battery cell according to any one of the above embodiments.

[0025] Since the battery includes the above-mentioned battery cell, the battery at least includes all the beneficial effects of the above-mentioned battery cell, which will not be elaborated herein.

[0026] The electrical device according to the embodiment of the present application includes the battery according to the above embodiment or the battery cell according to any one of the above embodiments.

[0027] Since the electrical device includes the above-mentioned battery or battery cell, the electrical device at least includes all the beneficial effects of the above-mentioned battery or battery cell, which will not be elaborated herein.

[0028] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented according to the content of the specification. And in order to make the above and other objects, features and advantages of the present application more obvious and understandable, the specific embodiments of the present application are specifically given below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of illustrating the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to denote the same components. In the drawings:

[0030] Figure 1 is a schematic structural diagram of an electrical device provided by some embodiments of the present application;

[0031] Figure 2 is an explosion schematic diagram of a battery provided by some embodiments of the present application;

[0032] Figure 3 is an explosion schematic diagram of a battery cell provided by some embodiments of the present application;

[0033] Figure 4 is a schematic structural diagram of a battery cell provided by some embodiments of the present application;

[0034] Figure 5 is Figure 4 a cross-sectional view of the battery cell in the A-A direction of

[0035] Figure 6 is Figure 5 an enlarged view of part B of the battery cell of

[0036] Figure 7 is Figure 6 an enlarged view of part C of the battery cell of

[0037] Figure 8 is Figure 3 an enlarged view of part D of the battery cell of

[0038] Figure 9 is a partial schematic structural diagram of a battery cell provided by some embodiments of the present application.

[0039] Explanation of reference numerals:

[0040] Battery cell 100; housing 10; first wall 12; first part 120; second part 121; splicing part 101; electrode assembly 20; insulating film 30; side wall 31; recess 310; first sub-wall 311; second sub-wall 312; inner surface 122 of the first wall; body 313; welding auxiliary 40; first electrode assembly 21; second electrode assembly 22; gap 23; protrusion 314; first straight part 210; first bending part 211; second straight part 220; second bending part 221; bottom wall 32; avoidance groove 320; end cap 14; housing body 15; opening 150; insulating part 50; side surface 51; groove 510; second wall 13; electrical equipment 1000; battery 200; controller 300; motor 400; box body 201; first box body 202; second box body 203. Detailed implementation mode

[0041] The embodiments of the technical solutions of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solutions of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0042] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above drawings are intended to cover non-exclusive inclusion.

[0043] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, "a plurality" means more than two unless otherwise specifically defined.

[0044] Referring to "embodiment" herein means that a specific feature, structure or characteristic described in connection with the embodiment can be included in at least one embodiment of the present application. The appearance of this phrase at 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. Those skilled in the art will explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0045] In the description of the embodiments of the present application, the term "and / or" is merely a relationship describing associated objects, indicating that three relationships may exist. For example, A and / or B may represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0046] In the description of the embodiments of the present application, the term "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0047] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of the present application.

[0048] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may also be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0049] Currently, from the perspective of the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power stations, but also widely used in electric transportation such as electric bicycles, electric motorcycles, and electric vehicles, as well as in many fields such as aerospace. With the continuous expansion of the application fields of batteries, the market demand is also continuously increasing.

[0050] In the manufacturing process of battery cells, in order to meet the high-temperature resistance requirements of the battery cell casings, materials such as steel and titanium alloy are introduced as the casings of battery cells. However, due to the high strength of steel and titanium alloy materials, it is difficult to form them by processes such as stretching.

[0051] To solve the problem of difficult molding, a splicing molding technique can be adopted to complete the molding of the housing. For example, two sub-housings are spliced into one housing by welding or bonding. However, after splicing, the thickness at the joint of the two sub-housings is relatively large, which may cause interference with the insulating film accommodated in the housing, resulting in the rupture of the insulating film and further reducing the reliability of the battery cell.

[0052] To solve the problem that when forming the housing of a battery cell by splicing, the thickness of the splicing part is relatively large, which is likely to interfere with the insulating film and cause the insulating film to rupture, the distance between the splicing part and the insulating film can be increased, thereby reducing the probability of interference between the splicing part and the insulating film, reducing the risk of rupture of the insulating film, and improving the reliability of the battery cell.

[0053] Based on the above considerations, an embodiment of the present application provides a battery cell. An indentation is designed on the insulating film of the battery cell. The indentation indents the insulating film away from the splicing part, and the indentation is disposed opposite to the splicing part. Thus, there is a relatively large distance between the insulating film and the splicing part, which can reduce the probability of interference between the splicing part and the insulating film, reduce the risk of rupture of the insulating film, and improve the reliability of the battery cell.

[0054] Please refer to Figure 1 , Figure 1 FIG. is a schematic structural diagram of an electrical device 1000 provided in some embodiments of the present application. The electrical device 1000 of the embodiment of the present application uses a battery or a battery cell as a power source. The electrical device 1000 may be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. Among them, the electric toy may include a fixed or mobile electric toy, such as a game console, an electric vehicle toy, an electric ship toy, and an electric aircraft toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spaceship, etc.

[0055] For the convenience of description, the following embodiments will be described by taking a vehicle as an example of an electrical device 1000 according to the embodiment of the present application.

[0056] A battery 200 is disposed inside the vehicle. The battery 200 may be disposed at the bottom, head, or tail of the vehicle. The battery 200 can be used for power supply of the vehicle. For example, the battery 200 can be used as an operating power source of the vehicle.

[0057] The vehicle may further include a controller 300 and a motor 400. The controller 300 is used to control the battery 200 to supply power to the motor 400. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle.

[0058] In the embodiments of the present application, the battery 200 can not only serve as the operating power source of the vehicle, but also as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0059] Please refer to Figure 2 , Figure 2 which is an explosion schematic diagram of the battery 200 provided in some embodiments of the present application. The battery 200 includes battery cells 100 and a box body 201, and the box body 201 is used to accommodate the battery cells 100.

[0060] In the embodiments of the present application, the battery cell 100 can include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, magnesium-ion batteries, etc., and the embodiments of the present application are not limited thereto. The battery cell 100 can be in the shape of a cylinder, a flat body, a cuboid or other shapes, and the embodiments of the present application are not limited thereto either. Generally, the battery cell 100 is divided into three types according to the encapsulation method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application are not limited thereto either.

[0061] The battery 200 mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells 100 to provide higher voltage and capacity. For example, the battery 200 mentioned in the embodiments of the present application can include a battery module or a battery pack, etc. The battery 200 generally includes a box body 201 for encapsulating one or more battery cells 100. The box body 201 can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells 100.

[0062] Among them, the box body 201 is a component for accommodating the battery cells 100. The box body 201 provides an accommodation space for the battery cells 100, and the box body 201 can adopt various structures. In some embodiments, the box body 201 can include a first box body 202 and a second box body 203. The first box body 202 and the second box body 203 are covered with each other to define an accommodation space for accommodating the battery cells 100. The first box body 202 and the second box body 203 can be of various shapes, such as a cuboid, a cylinder, etc. The first box body 202 can be a hollow structure with one side open, and the second box body 203 can also be a hollow structure with one side open. The open side of the second box body 203 is covered on the open side of the first box body 202, then the box body 201 with an accommodation space is formed. It can also be that the first box body 202 is a hollow structure with one side open, and the second box body 203 is a plate-like structure. The second box body 203 is covered on the open side of the first box body 202, then the box body 201 with an accommodation space is formed. The first box body 202 and the second box body 203 can be sealed through a sealing element, and the sealing element can be a sealing ring, a sealing glue, etc.

[0063] In battery 200, when there are multiple battery cells 100, the multiple battery cells 100 can be connected in series, in 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 100. It can be that multiple battery cells 100 are first connected in series, in parallel, or in a combined series-parallel connection to form a battery module, and then multiple battery modules are connected in series, in parallel, or in a combined series-parallel connection to form an entirety and are accommodated in the box body 201. It can also be that all the battery cells 100 are directly connected in series, in parallel, or in a combined series-parallel connection together, and then the entirety formed by all the battery cells 100 is accommodated in the box body 201.

[0064] In some embodiments, the battery 200 may further include a busbar component. The multiple battery cells 100 can be electrically connected through the busbar component to achieve series, parallel, or combined series-parallel connection of the multiple battery cells 100. The busbar component can be a metal conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0065] In some embodiments, the battery 200 can be an energy storage device. The energy storage device includes an energy storage container, an energy storage electrical cabinet, etc.

[0066] Please refer to Figure 3 , Figure 3 which is an exploded view of the battery cell 100 provided in some embodiments of the present application. The battery cell 100 according to the embodiment of the present application includes a housing 10, an electrode assembly 20, and an insulating film 30. The housing 10 includes a first wall 12. The first wall 12 includes a first portion 120 and a second portion 121. The first portion 120 and the second portion 121 are spliced to form a splicing portion 101. The electrode assembly 20 is disposed in the housing 10. The insulating film 30 is received in the housing 10 and covers at least a portion of the electrode assembly 20. The insulating film 30 includes a side wall 31 opposite to the first wall 12. The side wall 31 is provided with a recess 310 recessed away from the splicing portion 101, and the recess 310 is disposed opposite to the splicing portion 101.

[0067] Specifically, the housing 10 is a structure for accommodating components such as the electrode assembly 20. The first wall 12 can be a side wall 31 of the housing 10. The first portion 120 and the second portion 121 can be two portions formed along the width direction of the first wall 12, and the width direction of the first wall 12 can be perpendicular to the height direction of the housing 10. The first portion 120 and the second portion 121 can be spliced by bonding, welding, etc. to form the splicing portion 101. For example, when the first portion 120 and the second portion 121 are spliced by welding, the splicing portion 101 is the weld formed during welding.

[0068] The electrode assembly 20 is a component in the battery cell 100 where electrochemical reactions occur. The housing 10 of the battery cell 100 may contain one or more electrode assemblies 20. The electrode assembly 20 is mainly formed by winding or laminating a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive electrode sheet and the negative electrode sheet having active materials constitute the main body of the electrode assembly 20, and the portions of the positive electrode sheet and the negative electrode sheet without active materials respectively constitute the electrode tabs. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or separately at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the electrode tabs are connected to the electrode terminals to form a current loop.

[0069] The insulating film 30 is located between the electrode assembly 20 and the housing 10, and is used to isolate the electrode assembly 20 from the inner wall of the housing 10, so as to reduce the probability of short circuit caused by the direct contact between the electrode assembly 20 and the inner wall. The insulating film 30 may cover at least a part of the outer peripheral surface of the electrode assembly 20.

[0070] Please refer to Figure 4 、 Figure 5 、 Figure 6 and Figure 7 , Figure 4 are schematic structural diagrams of the battery cell 100 provided in some embodiments of the present application; Figure 5 is Figure 4 a cross-sectional view of the battery cell 100 in the A-A direction;

[0071] Figure 6 is Figure 5 an enlarged view of part B of the battery cell 100; Figure 7 is Figure 6 an enlarged view of part C of the battery cell 100. The shape of the recess 310 may be zigzag, curved, or other shapes. The recess 310 may be formed by bending or folding a partial area of the side wall 31 of the insulating film 30. For example, the side wall 31 may include a first sub-wall 311 and a second sub-wall 312. Both the first sub-wall 311 and the second sub-wall 312 may be folded in a direction away from the splicing portion 101 to form the recess 310. After folding, the first sub-wall 311 and the second sub-wall 312 may be stacked together.

[0072] Please refer to Figure 6 and Figure 7 , the distance between the recess 310 and the inner surface 122 of the first wall 12 is the first distance d1. The side wall 31 includes a body 313 connected to the recess 310. The distance between the body 313 and the inner surface 122 of the first wall 12 is the second distance d2, and the first distance d1 is greater than the second distance d2.

[0073] Among them, the inner surface 122 of the first wall 12 refers to the surface of the first wall 12 close to the electrode assembly 20. The body 313 can be the part of the side wall 31 of the insulating film 30 directly connected to the recess 310, forming the main structure of the side wall 31. The first distance d1 refers to the maximum distance between each part of the recess 310 and the inner surface 122 of the first wall 12. The second distance d2 refers to the maximum distance between each part of the body 313 and the inner surface 122 of the first wall 12.

[0074] Since the first distance d1 is greater than the second distance d2, the distance between the recess 310 and the inner surface 122 of the first wall 12 is larger, and the probability of interference between the recess 310 and the splicing part 101 is lower.

[0075] The insulating film 30 can be made of a flexible material. The insulating film 30 can be a polyester film, a polypropylene film, a polyethylene film, etc. In one embodiment, the insulating film 30 can be a mylar film. The mylar film is a kind of polyester film. The mylar film has a high dielectric strength and a low dielectric constant, which makes it a good electrical insulating material. It can effectively isolate the electrode assembly 20 and the inner wall of the housing 10, thereby effectively reducing the probability of the battery cell 100 short - circuiting and improving the reliability of the battery cell 100. At the same time, the mylar film has good chemical stability and is not easily corroded by the electrolyte, and can remain stable in the chemical environment inside the battery cell 100 for a long time.

[0076] In addition, the mylar film has a high tensile strength and toughness. This makes the mylar film easy to fold to form the recess 310.

[0077] In the battery cell 100 of the embodiment of the present application, the setting of the recess 310 can increase the distance between the insulating film 30 and the splicing part 101, thereby reducing the probability of interference between the splicing part 101 at the connection of the first part 120 and the second part 121 and the insulating film 30, reducing the risk of the insulating film 30 breaking, and improving the reliability of the battery cell 100.

[0078] In addition, since the insulating film 30 covers at least part of the electrode assembly 20, the insulating film 30 can isolate the electrode assembly 20 and the housing 10 to provide an insulating function, thereby reducing the probability of the battery cell 100 short - circuiting or other electrical failures.

[0079] In addition, the housing 10 is formed by splicing two parts, which simplifies the manufacturing process of the battery cell 100 and makes it more convenient to assemble the electrode assembly 20 and the insulating film 30.

[0080] Please refer to Figure 6 and Figure 7, in some embodiments, the first part 120 and the second part 121 are welded to form a splicing part 101. The battery cell 100 includes a welding auxiliary 40 disposed on the inner surface 122 of the first wall 12 and connected to the splicing part 101.

[0081] Specifically, the shape of the welding auxiliary 40 can be a regular shape such as a boss shape or a prism shape, or an irregular shape to meet the needs of the welding process. The welding auxiliary 40 can be a backing, gasket or other structure disposed at the splicing joint formed by welding. The welding auxiliary 40 can be made of a material compatible with the material of the housing 10. For example, if the housing 10 is made of aluminum alloy, the welding auxiliary 40 can be made of the same aluminum alloy material or other materials with high temperature resistance and low oxidation, such as stainless steel or special alloys.

[0082] The welding auxiliary 40 helps to reduce defects that may occur during welding, such as pores, cracks or incomplete penetration, and improve the welding yield. However, the welding auxiliary 40 has a certain thickness and is prone to interference with the insulating film 30. Therefore, by disposing the welding auxiliary 40 at the splicing joint, it can be opposite to the recessed portion 310, thereby reducing the probability of interference between the welding auxiliary 40 and the insulating film 30, reducing the risk of rupture of the insulating film 30, and improving the reliability of the battery cell 100.

[0083] Please refer to Figure 6 and Figure 7 , in some embodiments, along the arrangement direction P of the first part 120 and the second part 121, the length L1 of the recessed portion 310 is greater than the length L2 of the welding auxiliary 40.

[0084] In this way, by making the length L1 of the recessed portion 310 greater than the length L2 of the welding auxiliary 40, a wider protection area can be provided for the insulating film 30, and the longer recessed portion 310 helps to further reduce the probability of interference between the welding auxiliary 40 and the insulating film 30.

[0085] Please refer to Figure 6 and Figure 7 , in some embodiments, the electrode assembly 20 includes a first electrode assembly 21 and a second electrode assembly 22 connected to the first electrode assembly 21. Both the first electrode assembly 21 and the second electrode assembly 22 are disposed within the housing 10. A gap 23 is formed between the first electrode assembly 21 and the second electrode assembly 22. A protruding portion 314 is formed on the side of the sidewall 31 of the insulating film 30 facing the electrode assembly 20, and the protruding portion 314 is disposed opposite to the recessed portion 310, and the protruding portion 314 is at least partially located within the gap 23.

[0086] Specifically, both the first electrode assembly 21 and the second electrode assembly 22 include a positive electrode sheet, a negative electrode sheet, and a separator that separates the positive electrode sheet and the negative electrode sheet. In the battery cell 100, the electrode assembly 20 can be formed by winding. Therefore, there are spaced areas in the winding area for different electrode assemblies 20. The gap 23 can be the spaced area between the first electrode assembly 21 and the second electrode assembly 22.

[0087] The shape of the protrusion 314 can be zigzag, curved, or other shapes. The protrusion 314 can be formed by bending or folding a partial area of the side wall 31 of the insulating film 30. After folding, a protrusion 314 can be formed on the side of the side wall 31 facing the electrode assembly 20, and a recess 310 can be formed on the side away from the electrode assembly 20.

[0088] In this way, the gap 23 can provide a larger space for the protrusion 314 and the recess 310, so that the distances between the protrusion 314 and the recess 310 and the splicing part 101 are larger, thereby further reducing the probability of interference between the splicing part 101 and the insulating film 30.

[0089] Please refer to Figure 6 , in some embodiments, the first electrode assembly 21 includes a first straight portion 210 and a first bent portion 211 connected to the first straight portion 210, the second electrode assembly 22 includes a second straight portion 220 and a second bent portion 221 connected to the second straight portion 220, and a gap 23 is formed between the first bent portion 211 and the second bent portion 221.

[0090] Specifically, both the first electrode assembly 21 and the second electrode assembly 22 can be formed by winding. The first straight portion 210 is the straight portion formed when the first electrode assembly 21 is wound. The first bent portion 211 is the bent portion formed when the first electrode assembly 21 is wound.

[0091] The second straight portion 220 is the straight portion formed when the second electrode assembly 22 is wound. The second bent portion 221 is the bent portion formed when the second electrode assembly 22 is wound. The second straight portion 220 can be arranged in parallel with the first straight portion 210. The second bent portion 221 can be arranged in the area of the second electrode assembly 22 close to the first bent portion 211.

[0092] In this way, the gap 23 is formed by the inherent structure of the electrode assembly 20, without the need to additionally form structures such as holes or grooves on the first electrode assembly 21 or the second electrode assembly 22, which maintains the integrity of the electrode assembly 20, improves the manufacturing efficiency, and reduces the manufacturing cost.

[0093] Please refer to Figure 6 and Figure 7, in some embodiments, along the arrangement direction P of the first part 120 and the second part 121, the length L3 of the gap 23 is greater than the length L1 of the recess 310.

[0094] Specifically, the length L3 of the gap 23 refers to the distance between the center lines of the first electrode assembly 21 and the second electrode assembly 22.

[0095] Thus, since the length L3 of the gap 23 is greater than the length L1 of the recess 310, this provides sufficient space for the recess 310, thereby reducing the direct contact between the insulating film 30 and the electrode assembly 20 and lowering the probability of interference between the insulating film 30 and the electrode assembly 20.

[0096] Please refer to Figure 8 , Figure 8 is Figure 3 an enlarged view of part D of the battery cell 100. In some embodiments, the insulating film 30 includes a bottom wall 32, a side wall 31 is connected to the bottom wall 32, and an avoidance groove 320 is provided at a portion of the bottom wall 32 opposite to the splicing portion 101.

[0097] Specifically, the bottom wall 32 is the part of the insulating film 30 for supporting the side wall 31 and the electrode assembly 20. The side wall 31 and the bottom wall 32 can be integrally formed; the side wall 31 and the bottom wall 32 can also be separately formed and can be connected by an adhesive means. The insulating film 30 can wrap at least part of the electrode assembly 20 by folding, with the bottom wall 32 of the insulating film 30 as the support surface, and folding along the connection between the side wall 31 and the bottom wall 32 to wrap the electrode assembly 20 in the insulating film 30. The shape of the avoidance groove 320 can be a regular shape such as a rectangle or a circle, or an irregular shape.

[0098] Thus, the provision of the avoidance groove 320 can reduce the probability of interference between the splicing portion 101 and the insulating film 30, thereby reducing the risk of rupture of the insulating film 30 and improving the reliability of the battery cell 100.

[0099] Please refer to Figure 9 , Figure 9 is a partial structural schematic diagram of the battery cell 100 provided in some embodiments of the present application. In some embodiments, the housing 10 further includes an end cap 14 and a housing body 15 connected to the end cap 14. The housing body 15 is provided with an opening 150, the end cap 14 seals the opening 150, and the battery cell 100 further includes an insulating member 50 disposed on the side of the end cap 14 facing the electrode assembly 20. The end cap 14 seals the opening 150. The insulating member 50 includes a side surface 51 opposite to the side wall 31, and a groove 510 is formed on the side surface 51, and at least part of the recess 310 is disposed in the groove 510.

[0100] Specifically, the shape of the opening 150 of the housing 10 can be a regular shape, such as a square, or an irregular shape.

[0101] The end cap 14 refers to a component that covers the opening 150 of the housing 10 to isolate the interior of the housing 10 from the external environment. Without limitation, the shape of the end cap 14 can be adapted to the shape of the housing 10 to fit the housing 10. The end cap 14 can be made of a material with a certain hardness and strength, such as aluminum alloy. In this way, the end cap 14 is not easily deformed when subjected to extrusion and collision, enabling the battery cell 100 to have higher structural strength and improved safety performance.

[0102] In some embodiments, a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 100 reaches a threshold value can also be provided on the end cap 14. The material of the end cap 14 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not make special restrictions on this.

[0103] The insulating member 50 can be used to isolate the electrical connection components in the housing 10 from the end cap 14 to reduce the risk of short circuit. The insulating member 50 can be made of polypropylene, polyethylene or other plastic materials. The insulating member 50 and the recessed portion 310 of the insulating film 30 can be heat - melted and connected.

[0104] In this way, the setting of the groove 510 can match the shape and structure of the recessed portion 310, thereby reducing the probability of interference between the insulating member 50 and the insulating film 30, reducing the risk of rupture of the insulating film 30, and improving the reliability of the battery cell 100.

[0105] In certain embodiments, the side wall 31 is connected to the side surface 51 to form a connection portion, and at least part of the connection portion is disposed in the recessed portion 310.

[0106] Specifically, the side wall 31 and the side surface 51 can be connected by bonding, heat - melting connection or other means. After connection, a connection portion can be formed between the side wall 31 and the side surface 51. The connection portion can be partially disposed in the recessed portion 310 or entirely disposed in the recessed portion 310.

[0107] It can be understood that since the connection portion has a certain thickness, if the connection portion is entirely disposed outside the recessed portion 310, interference may occur between the connection portion and the first wall 12, resulting in rupture of the insulating film 30.

[0108] Therefore, at least part of the connection portion is disposed in the recessed portion 310, which can make the connection portion have a larger distance from the first wall 12. This can reduce the probability of interference between the connection portion and the first wall 12 or the splicing portion 101, thereby reducing the risk of rupture of the insulating film 30 and improving the reliability of the battery cell 100.

[0109] In some embodiments, the housing 10 includes a second wall 13 connected to the first wall 12, and the area of the second wall 13 is larger than the area of the first wall 12.

[0110] Specifically, the first wall 12 and the second wall 13 can be integrally formed or connected by means such as welding. The areas of the second wall 13 and the first wall 12 both refer to the orthographic projection areas.

[0111] Thus, since the splicing portion 101 is provided on the first wall 12 with a smaller area, this reduces the occupation of the effective space inside the battery cell 100 by the splicing portion 101, and can adapt to the layout of the electrode assembly 20 and the insulating film 30, thereby contributing to the setting of the recessed portion 310.

[0112] Please refer to Figure 1 , Figure 6 and Figure 7 , in a specific embodiment, the battery cell 100 includes a housing 10, an electrode assembly 20, and an insulating film 30. The housing 10 includes a first wall 12. The first wall 12 includes a first portion 120 and a second portion 121. The first portion 120 and the second portion 121 are welded and formed with a splicing portion 101. The electrode assembly 20 is disposed inside the housing 10. The insulating film 30 is received inside the housing 10 and covers at least part of the electrode assembly 20.

[0113] The electrode assembly 20 includes a first electrode assembly 21 and a second electrode assembly 22 connected to the first electrode assembly 21. Both the first electrode assembly 21 and the second electrode assembly 22 are disposed inside the housing 10. A gap 23 is formed between the first electrode assembly 21 and the second electrode assembly 22. The insulating film 30 includes a side wall 31 opposite to the first wall 12. The side wall 31 is provided with a recessed portion 310 recessed away from the splicing portion 101. The recessed portion 310 is disposed opposite to the splicing portion 101, and part of the recessed portion 310 is recessed into the gap 23. A welding auxiliary 40 is provided on the inner surface 122 of the first wall 12 at the splicing portion 101.

[0114] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it; 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 or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that: The battery cell comprises: A shell, the shell comprising a first wall, the first wall comprising a first part and a second part, the first part and the second part are spliced ​​to form a splicing portion; an electrode assembly, wherein the electrode assembly is disposed in the housing; An insulating film is accommodated in the shell and covers at least a portion of the electrode assembly. The insulating film includes a side wall opposite to the first wall, the side wall is provided with a recessed portion recessed away from the splicing portion, and the recessed portion is arranged opposite to the splicing portion.

2. The battery cell according to claim 1, characterized in that: The first portion and the second portion are welded to form the splicing portion, and the battery cell includes a welding auxiliary member disposed on the inner surface of the first wall and connected to the splicing portion.

3. The battery cell according to claim 2, characterized in that: Along an arrangement direction of the first portion and the second portion, a length of the recessed portion is greater than a length of the welding auxiliary component.

4. The battery cell according to claim 1, characterized in that: The electrode assembly includes a first electrode assembly and a second electrode assembly connected to the first electrode assembly, the first electrode assembly and the second electrode assembly are both arranged in the shell, a gap is formed between the first electrode assembly and the second electrode assembly, a protrusion is formed on the side of the side wall of the insulating film facing the electrode assembly, the protrusion is arranged opposite to the recessed portion, and the protrusion is at least partially located in the gap.

5. The battery cell according to claim 4, characterized in that: The first electrode assembly includes a first straight portion and a first curved portion connected to the first straight portion, the second electrode assembly includes a second straight portion and a second curved portion connected to the second straight portion, and the gap is formed between the first curved portion and the second curved portion.

6. The battery cell according to claim 1, characterized in that: The insulating film comprises a bottom wall, the side wall is connected to the bottom wall, and a avoiding groove is provided at a position of the bottom wall opposite to the splicing portion.

7. The battery cell according to claim 1, characterized in that: The shell includes an end cover and a shell body connected to the end cover, the shell body is provided with an opening, and the end cover covers the opening. The battery cell also includes an insulating member arranged on the side of the end cover facing the electrode assembly, the insulating member includes a side surface opposite to the side wall, the side surface is formed with a groove, and the recessed portion is at least partially arranged in the groove.

8. The battery cell according to claim 7, characterized in that: The side wall is connected to the side surface to form a connecting portion, and the connecting portion is at least partially disposed in the recessed portion.

9. The battery cell according to claim 1, characterized in that: The housing further includes a second wall connected to the first wall, and an area of ​​the second wall is greater than an area of ​​the first wall.

10. A battery, characterized in that: The battery comprises the battery cell according to any one of claims 1 to 9.

11. An electrical device, characterized in that: The electrical equipment comprises the battery cell according to any one of claims 1 to 9 or the battery according to claim 10.

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