Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device. The battery monomer comprises a shell, an insulating film and a connecting piece, the outer surface of the shell comprises two first surfaces, a second surface and a third surface, the two first surfaces are oppositely arranged, the second surface is connected with the two first surfaces, the third surface is connected with the two first surfaces, and the first surfaces, the second surface and the third surface intersect with one another. The insulating film is integrally arranged and comprises a main body area and an ending area, the main body area covers the two first surfaces and the second surface, the ending area covers the third surface and is connected with the main body area, the ending area comprises a plurality of folding lugs, the folding lugs are at least partially overlapped, and the folding lugs comprise first folding lugs and second folding lugs; a part of the first folding lug is self-folded to form a folding part with a plurality of layers of insulating films, and the folding part is laminated on one side, back to the third surface, of the second folding lug. And at least part of the connecting piece is connected between the folding part and the second folding lug. According to the invention, the reliability of the battery monomer can be effectively improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0003] In the development of battery technology, the reliability of battery cells directly affects the reliability, cost of use, and user experience of end products. Therefore, how to effectively improve the reliability of battery cells is a technical problem that needs to be solved urgently in battery technology. Utility Model Content

[0004] In view of the above problems, the present application provides a battery cell, a battery and an electrical device, which can effectively improve the reliability of the battery cell.

[0005] In a first aspect, an embodiment of the present application provides a battery cell, comprising a housing, an insulating film, and a connector. The outer surface of the housing comprises two first surfaces, a second surface, and a third surface. The two first surfaces are arranged opposite each other, the second surface connects the two first surfaces, and the third surface connects the two first surfaces. The first surface, the second surface, and the third surface intersect with each other. The insulating film is integrally arranged and comprises a main body region and a tail region. The main body region covers the two first surfaces and the second surface. The tail region covers the third surface and connects the main body region. The tail region comprises a plurality of folded ears. The plurality of folded ears at least partially overlap. The plurality of folded ears comprise a first folded ear and a second folded ear. A portion of the first folded ear folds onto itself to form a folded portion having multiple layers of insulating film. The folded portion is stacked on the side of the second folded ear facing away from the third surface. At least a portion of the connector is connected between the folded portion and the second folded ear.

[0006] The above technical solution provides a connector, at least part of which is connected between the folding portion and the second folding ear to reduce or eliminate the gap between the folding portion and the second folding ear, thereby increasing the creepage distance between the outer shell at the position where the folding portion is located and the external environment, thereby reducing the risk of insulation failure when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell, thereby improving the reliability of the battery cell.

[0007] In some embodiments of the first aspect, at least a portion of the folded edge of the folded portion is exposed on a side of the second flap facing away from the third surface. The folded edge exposed on the side of the second flap facing away from the third surface has a first projection on the third surface along a direction perpendicular to the third surface, and the connector connected between the folded portion and the second flap has a second projection on the third surface along a direction perpendicular to the third surface, with the first projection being located within the second projection.

[0008] The connector of the above technical solution can connect the fold edge exposed on the side surface of the second fold ear facing away from the third surface with the second fold ear, so as to cut off the conductive relationship between the gap between the folded part and the second fold ear and the external environment, thereby reducing the blocking of electrolyte from entering the gap when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell, and further reducing the risk of insulation failure to improve the reliability of the battery cell.

[0009] In some embodiments of the first aspect, the folded portion has a third projection on the third surface along a direction perpendicular to the third surface, and the third projection coincides with the second projection.

[0010] The connector of the above technical solution can seal the gap between the entire folded portion and the second folded ear, thereby further reducing the risk of insulation failure when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell.

[0011] In some embodiments of the first aspect, the first flap covers the connector.

[0012] The above technical solution can not only reduce the risk of impurities being absorbed by the connector, but also improve the consistency and appearance quality of the battery cells.

[0013] In some embodiments of the first aspect, the outer surface of the housing includes two third surfaces, the two first surfaces are arranged opposite each other along a first direction, the two third surfaces are arranged opposite each other along a second direction, each third surface connects the two first surfaces, the second surface is located on one side of the housing along the third direction and connects the first and third surfaces, and the first, second, and third directions are perpendicular to each other. The main body region includes two first sub-regions and a second sub-region, the two first sub-regions respectively cover the two first surfaces, and the second sub-region covers the second surface. The insulating film includes two tail regions, the two tail regions respectively cover the two third surfaces. There are two connectors, and the two connectors are respectively arranged corresponding to the two tail regions.

[0014] The wrapping method adopted in the above technical solution enables the tail area to be located on the side of the shell, thereby reducing the difficulty of setting the connector, which is beneficial to improving the production efficiency of the battery cell and reducing the cost.

[0015] In some embodiments of the first aspect, each tail area includes two first folding ears and a second folding ear, the first folding ear is connected to one end of the first sub-area close to the third surface, the two first folding ears located in the same tail area are respectively folded relative to each other from the two first sub-areas toward the third surface, and the second folding ear is connected to one end of the second sub-area close to the third surface, and is folded from the second sub-area toward the third surface.

[0016] The thickness of the folded portion of this wrapping method of the above technical solution is relatively small, that is, the number of insulating film layers in the folded portion is relatively small. On the one hand, it is beneficial to reduce the overall volume of the battery cell and can improve the energy density of the battery cell; on the other hand, since the thickness of the folded portion is relatively small, it can also reduce the degree of protrusion at the location of the connector, thereby reducing the risk of interference between the location of the connector and other components around the battery cell.

[0017] In some embodiments of the first aspect, the connector is integrally formed and includes a first connector and two second connectors. The first connector is connected to at least one of the third surface and the second folded ear, and in the second direction, two side edges of the first connector along the first direction overlap with two side edges of the third surface along the first direction. The two second connectors are respectively connected to two side edges of the first connector along the first direction, and the two second connectors are respectively connected to inner sides of the two first folded ears.

[0018] The above technical solution can increase the layout area of ​​the connector, further increasing the creepage distance between the outside world and the external environment, thereby further improving the reliability of the battery cell. In addition, the first connecting part connects the two second connecting parts, forming an integrated structure of the connector, which can simplify the installation of the connector and improve the overall production efficiency of the battery cell.

[0019] In some embodiments of the first aspect, two first folded ears located in the same tail region partially overlap.

[0020] The above technical solution can reduce the risk of incomplete coverage of the tail area causing part of the outer surface of the shell to be exposed to the external environment by overlapping the two first folded ears located in the same tail area, thereby improving the coverage effect of the insulating film and thus improving the reliability of the battery cell.

[0021] In some embodiments of the first aspect, the overlapping parts of the two first folded ears located in the same tail area have a fourth projection on the third surface along the second direction, and the second connecting portion has a fifth projection on the third surface along the second direction, and the fourth projection and the fifth projection do not overlap.

[0022] The above technical solution can effectively reduce the overall thickness of the tail area, that is, reduce the maximum number of insulating film layers in the tail area. On the one hand, it is beneficial to reduce the overall volume of the battery cell and can improve the energy density of the battery cell; on the other hand, since the thickness of the folding portion is relatively small, it can also reduce the degree of protrusion at the location of the second connecting portion, thereby reducing the risk of interference between the location of the second connecting portion and other components around the battery cell.

[0023] In some embodiments of the first aspect, the folded portions of two first flaps located in the same tail region do not overlap.

[0024] The aforementioned technical solution features a thinner tail region, meaning it contains fewer layers of insulating film. This helps reduce the overall volume of the battery cell, thereby increasing its energy density. Furthermore, it provides more space for connectors, simplifying their installation and improving battery cell production efficiency and reducing costs.

[0025] In a second aspect, the present application provides a battery comprising the battery cell provided in any embodiment of the first aspect.

[0026] In a third aspect, the present application provides an electrical device, which includes a battery cell provided by any embodiment of the first aspect, and the battery cell is used to provide electrical energy.

[0027] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0029] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0030] Figure 2 A schematic diagram of an exploded structure of a battery provided in some embodiments of the present application;

[0031] Figure 3 A schematic structural diagram of a battery module provided in some embodiments of the present application;

[0032] Figure 4A schematic diagram of the three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0033] Figure 5 A schematic diagram of the three-dimensional structure of the positional relationship between a battery cell and an insulating film during the coating process provided by some embodiments of the present application;

[0034] Figure 6 A schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application, in which a first surface is bonded to a main area of ​​an insulating film, and a second surface is bonded to a main area of ​​the insulating film during a coating process;

[0035] Figure 7 A schematic diagram of a three-dimensional structure of a battery cell provided by some embodiments of the present application, wherein a third surface and a second folded ear of an insulating film are bonded together during a coating process;

[0036] Figure 8 A schematic diagram of the three-dimensional structure of the positional relationship between the outer shell, insulating film and connector of a battery cell during the coating process provided by some embodiments of the present application;

[0037] Figure 9 This is a schematic diagram of the three-dimensional structure of a battery cell after the package is completed, provided in some embodiments of the present application.

[0038] The accompanying drawings in the specific implementation manner are as follows:

[0039] 1. Vehicle; 2. Battery; 3. Controller; 4. Motor; 5. Housing; 5a. First housing portion; 5b. Second housing portion; 5c. Accommodation space; 6. Battery module; 7. Battery cell;

[0040] 10. Outer shell; 11. First surface; 12. Second surface; 13. Third surface; 20. Insulating film; 21. Main body area; 22. Tail area; 221. First fold ear; 2211. Folding portion; 2212. Crease edge; 2213. Fitting portion; 222. Second fold ear; 30. Connector; 31. First connecting portion; 32. Second connecting portion; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0041] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0042] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0043] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0044] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0045] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0046] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0047] The term "plurality" used in this application refers to two or more (including two).

[0048] In this application, the term "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering.

[0049] In the embodiment of the present application, the battery cell may be a secondary battery cell. A secondary battery cell refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0050] The battery cell can be a lithium-ion battery cell, a sodium-ion battery cell, a sodium-lithium-ion battery cell, a lithium metal battery cell, a sodium metal battery cell, a lithium-sulfur battery cell, a magnesium-ion battery cell, a nickel-hydrogen battery cell, a nickel-cadmium battery cell, a lead-acid battery cell, etc., and the embodiments of the present application are not limited to this.

[0051] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film.

[0052] As an example, the battery cells may be cylindrical, prismatic, soft-pack or other shaped battery cells. Prismatic battery cells include square-shell, blade-shaped, and polygonal batteries. Polygonal batteries may be, for example, hexagonal batteries.

[0053] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity.

[0054] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0055] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0056] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0057] In some embodiments, the battery may be an energy storage device, including an energy storage container, an energy storage cabinet, and the like.

[0058] With the development of new energy technology, batteries are used more and more widely, for example, in mobile phones, laptops, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes and power tools.

[0059] A battery generally includes a housing and a plurality of battery cells. The outer surface of the housing of the battery cells is generally covered with an insulating film to protect the battery cells.

[0060] In current battery cells, the insulating film coating is typically performed using a circular or U-shaped wrapping method, which is simple, convenient, and quick. However, this wrapping method typically results in a folded, multi-layered insulating film in portions of the outer shell. Furthermore, the insulating film is typically adhesively coated on one side. Within this folded, multi-layered insulating film, a portion of the insulating film folds back on itself, leaving no adhesive on either side of the folded portion along its thickness. Consequently, a gap forms between the folded portion and the adjacent insulating film. In the event of an abnormality such as electrolyte leakage or thermal runaway in the battery cell, the gap between the folded portion and the adjacent insulating film can create a capillary effect, allowing electrolyte to enter the gap and, under the action of voltage, conduct electricity between the outer shell and the casing, causing insulation failure and thus impacting the reliability of the battery cell.

[0061] Based on the above considerations, an embodiment of the present application provides a battery cell, which includes a shell, an insulating film, and a connector. The outer surface of the shell includes two first surfaces, a second surface, and a third surface. The two first surfaces are arranged opposite to each other, the second surface connects the two first surfaces, and the third surface connects the two first surfaces. The first surface, the second surface, and the third surface intersect with each other. The insulating film is integrally arranged and includes a main body area and a tail area. The main body area covers the two first surfaces and the second surface. The tail area covers the third surface and connects the main body area. The tail area includes a plurality of folded ears. The plurality of folded ears at least partially overlap. The plurality of folded ears include a first folded ear and a second folded ear. A portion of the first folded ear folds itself to form a folded portion having multiple layers of insulating film. The folded portion is stacked on the side of the second folded ear facing away from the third surface. At least a portion of the connector is connected between the folded portion and the second folded ear.

[0062] A portion of the first tab folds onto itself to form a folded portion with multiple layers of insulating film. The folded portion has no adhesive on either side along its thickness, resulting in a gap between the folded portion and the second tab. Thus, the above technical solution reduces or eliminates the gap between the folded portion and the second tab by providing a connector, at least partially connected between the folded portion and the second tab. This increases the creepage distance between the housing at the location of the folded portion and the external environment, thereby reducing the risk of insulation failure in the event of abnormalities such as electrolyte leakage or thermal runaway in the battery cell, thereby improving the reliability of the battery cell.

[0063] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0064] Electrical devices may include vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and electric tools, etc. Vehicles may include fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles may include pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0065] It should be understood that the technical solutions described in the embodiments of the present application are not limited to the batteries and electrical equipment described above, but can also be applied to all batteries including battery boxes and electrical equipment using batteries. However, for the sake of simplicity, the following embodiments are explained using electric vehicles as an example.

[0066] Figure 1 A schematic structural diagram of a vehicle provided for some embodiments of the present application.

[0067] Continue to refer Figure 1 The vehicle 1 is provided with a battery 2 inside. The battery 2 can be provided at the bottom, head, or tail of the vehicle 1. The battery 2 can be used to power the vehicle 1. For example, the battery 2 can be used as an operating power source for the vehicle 1.

[0068] The vehicle 1 may further include a controller 3 and a motor 4 . The controller 3 is used to control the battery 2 to supply power to the motor 4 , for example, to meet the power requirements of the vehicle 1 during startup, navigation, and driving.

[0069] In some embodiments of the present application, the battery 2 can not only serve as the operating power source of the vehicle 1, but also serve as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0070] Figure 2 A schematic diagram of the explosion structure of a battery provided in some embodiments of the present application.

[0071] Continue to refer Figure 2 The battery 2 includes a box body 5 and a battery cell, and the battery cell is accommodated in the box body 5.

[0072] The housing 5 is used to house battery cells and can have various structures. In some embodiments, the housing 5 can include a first housing portion 5a and a second housing portion 5b. The first housing portion 5a and the second housing portion 5b overlap each other, and the first housing portion 5a and the second housing portion 5b together define a storage space 5c for accommodating the battery cells. The second housing portion 5b can be a hollow structure with one end open. The first housing portion 5a is a plate-like structure, and the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. The first housing portion 5a and the second housing portion 5b can also be hollow structures with one end open. The open side of the first housing portion 5a overlaps the open side of the second housing portion 5b to form the housing 5 with the storage space 5c. Of course, the first housing portion 5a and the second housing portion 5b can have various shapes, such as a cylinder, a rectangular parallelepiped, etc.

[0073] In order to improve the sealing performance after the first box body 5a and the second box body 5b are connected, a sealing member, such as a sealant, a sealing ring, etc., may also be provided between the first box body 5a and the second box body 5b.

[0074] Assuming that the first box body portion 5a covers the top of the second box body portion 5b, the first box body portion 5a can also be called an upper box cover, and the second box body portion 5b can also be called a lower box body.

[0075] In battery 2, there can be one or more battery cells. If there are multiple battery cells, they can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections. Multiple battery cells can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery module can be housed within housing 5. Alternatively, multiple battery cells can be first connected in series, in parallel, or in a hybrid configuration to form a battery module 6, and then multiple battery modules 6 can be connected in series, in parallel, or in a hybrid configuration to form a single unit housed within housing 5.

[0076] Figure 3 A schematic structural diagram of a battery module provided in some embodiments of the present application.

[0077] In some embodiments, referring to the figure, there are multiple battery cells 7, which are first connected in series, parallel, or in series to form a battery module 6. The multiple battery modules 6 are then connected in series, parallel, or in series to form a whole and accommodated in a box.

[0078] The multiple battery cells 7 in the battery module 6 can be electrically connected via a busbar component to achieve parallel connection, series connection, or mixed connection of the multiple battery cells 7 in the battery module 6 .

[0079] Figure 4 This is a schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application. Figure 5This is a schematic diagram of the three-dimensional structure of the positional relationship between a battery cell and an insulating film during the coating process provided by some embodiments of the present application. Figure 6 This is a schematic diagram of a three-dimensional structure of a battery cell provided in some embodiments of the present application, in which the first surface is bonded to the main area of ​​the insulating film and the second surface is bonded to the main area of ​​the insulating film during the coating process. Figure 7 This is a schematic diagram of a three-dimensional structure of a battery cell provided by some embodiments of the present application, wherein the third surface and the second folded ear of the insulating film are attached to each other during the coating process. Figure 8 This is a schematic diagram of the three-dimensional structure of the positional relationship between the outer shell, insulating film and connector of a battery cell during the coating process provided by some embodiments of the present application. Figure 9 This is a schematic diagram of the three-dimensional structure of a battery cell after the package is completed, provided in some embodiments of the present application.

[0080] refer to Figures 4 to 9 The embodiment of the present application provides a battery cell 7, which includes a housing 10, an insulating film 20, and a connector 30. The outer surface of the housing 10 includes two first surfaces 11, a second surface 12, and a third surface 13. The two first surfaces 11 are arranged opposite each other, the second surface 12 connects the two first surfaces 11, and the third surface 13 connects the two first surfaces 11. The first surface 11, the second surface 12, and the third surface 13 intersect with each other. The insulating film 20 is integrally provided and includes a main body region 21 and a tail region 22. The main body region 21 covers the two first surfaces 11 and the second surface 12. The tail region 22 covers the third surface 13 and connects the main body region 21. The tail region 22 includes a plurality of folded ears, which at least partially overlap. The plurality of folded ears include a first folded ear 221 and a second folded ear 222. A portion of the first folded ear 221 is folded onto itself to form a folded portion 2211 having multiple layers of insulating film. The folded portion 2211 is stacked on the side of the second folded ear 222 facing away from the third surface 13. At least a portion of the connecting member 30 is connected between the folding portion 2211 and the second folding ear 222 .

[0081] Exemplarily, the housing 10 is a component for forming the internal environment of the battery cell 7. The internal environment formed can be used to accommodate the electrode assembly, electrolyte and other components. The electrode assembly is a component in the battery cell 7 where electrochemical reactions occur. The electrode assembly is mainly formed by winding or stacking the positive electrode sheet and the negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute the tab. The positive electrode tab and the negative electrode tab can be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0082] Optionally, the housing 10 may be made of, but is not limited to, metal or non-metal materials. For example, the metal material may be copper, aluminum, or stainless steel; the non-metal material may be polyethylene, polypropylene, or polyvinyl chloride.

[0083] In some embodiments of the present application, the housing 10 is square, and the housing 10 includes a shell and an end cover, the shell has an opening, and the end cover covers the opening. The first surface 11, the second surface 12, and the third surface 13 are all arranged on the shell. The first surface 11 can be understood as the large surface on the circumferential side of the shell, wherein the circumferential side refers to the surface along the side surrounding the opening, and the large surface means the surface with a larger area on the circumferential side of the shell. One of the second surface 12 and the third surface 13 can be understood as the small surface on the circumferential side of the shell, and the other of the second surface 12 and the third surface 13 can be understood as the bottom surface of the shell, wherein the small surface means the surface with a smaller area on the circumferential side of the shell, and the bottom surface refers to the surface on the shell opposite to the opening.

[0084] In some examples, when the square housing 10 is coated with the insulating film 20 in a round-shaped coating manner, the first surface 11 is the large surface, the second surface 12 is the small surface, and the third surface 13 is the bottom surface.

[0085] In some examples, when the square housing 10 is coated with the insulating film 20 in a U-shaped coating manner, the first surface 11 is the large surface, the second surface 12 is the bottom surface, and the third surface 13 is the small surface.

[0086] In the embodiment disclosed herein, an insulating film 20 is coated on the outer surface of the housing 10. The insulating film 20 not only provides insulation protection for the battery cells 7, reducing the risk of short circuits during normal use, but also enhances the appearance of the battery cells 7. Optionally, the insulating film 20 may be made of, but is not limited to, polyethylene, polypropylene, or other polymer materials.

[0087] The insulating film 20 is integrally provided, which means that the insulating film 20 is already integrally provided before covering the housing 10 .

[0088] The main region 21 refers to the portion of the insulating film 20 that flatly covers the outer shell 10, while the tail region 22 refers to the portion of the insulating film 20 that folds over the outer shell 10. In other words, during the process of coating the battery cell 7 with the insulating film 20, the insulating film 20 first covers the first and second surfaces 11, 12 of the outer shell 10 to form the main region 21. The portion of the insulating film 20 that extends beyond the main region 21 serves as a plurality of flaps, which are then folded over and covered on the third surface 13 of the outer shell 10 to form the tail region 22. It should be noted that the main region 21 typically covers a larger area than the tail region 22.

[0089] It is understandable that, in the process of the plurality of folded ears being covered on the third surface 13 of the shell 10 by folding to form the end area 22 , the folding of each of the plurality of folded ears has a sequence.

[0090] The second folded ear 222 is the ear that is folded first and is attached to the third surface 13 in a flat manner. The first folded ear 221 is the ear that is folded later than the second folded ear 222. Since the insulating film 20 is integrally provided, the first folded ear 221 and the second folded ear 222 are connected. During the folding of the second folded ear 222, the portion of the first folded ear 221 adjacent to the second folded ear 222 is simultaneously folded, so that the portion of the first folded ear 221 adjacent to the second folded ear 222 is folded together with another portion of the first folded ear 221 to form a folded portion 2211 having two layers of insulating film. After the first folded ear 221 is folded, the folded portion 2211 is stacked on the side of the second folded ear 222 facing away from the third surface 13.

[0091] It should be noted that during the folding process of the second folded ear 222, the first folded ear 221 is affected by the folding of the second folded ear 222 to form the folded portion 2211. Depending on the specific folding method, a folded portion 2211 having two layers of insulating film, a folded portion 2211 having three layers of insulating film, or a folded portion 2211 having more layers of insulating film can be formed. In other words, the formation of the folded portion 2211 can be described as a folded structure having multiple layers of insulating film formed by self-folding of a portion of the first folded ear 221. In order to more clearly illustrate the embodiments of the present application, the following description will be based on an example in which the portion of the first folded ear 221 adjacent to the second folded ear 222 is folded in half with another portion of the first folded ear 221 to form the folded portion 2211 having two layers of insulating film.

[0092] Next, the specific structures of the embodiments of the present application are introduced in terms of the round-shaped packaging method and the U-shaped packaging method. Figures 5 to 8This is a schematic diagram of a specific step structure of a U-shaped encapsulation method. The specific step structure schematic diagram of the round-shaped encapsulation method can refer to the existing relevant step diagrams and will not be illustrated here.

[0093] In some examples, when the square shell 10 is coated with the insulating film 20 in a U-shaped coating method, the shell 10 includes two first surfaces 11, one second surface 12 and two third surfaces 13. The first surface 11 is the large surface among the circumferential side surfaces of the square shell 10, the second surface 12 is the bottom surface of the square shell 10, and the third surface 13 is the small surface among the circumferential side surfaces of the square shell 10.

[0094] The insulating film 20 has two tail regions 22 and six folded ears, wherein each tail region 22 is formed by three folded ears. Specifically, the insulating film 20 will first cover the two first surfaces 11 and the one second surface 12 of the shell 10 to form the main body region 21 and the six folded ears. For the convenience of description, the two third surfaces 13 are respectively configured as the first small face and the second small face, and the two tail regions 22 are respectively configured as the first tail region and the second tail region. Three of the six folded ears are connected to one end of the main body region 21 close to the first small face and surround the outer periphery of the first small face, and these three folded ears are folded toward the first small face to cover the first small face to form a first tail region; and the other three of the six folded ears are connected to one end of the main body region 21 close to the second small face and surround the outer periphery of the second small face, and these three folded ears are folded toward the second small face to cover the second small face to form a second tail region.

[0095] In the first tail region, two of the three folded ears in the first tail region are configured as two first folded ears 221, and another of the three folded ears in the first tail region is configured as a second folded ear 222. The two first folded ears 221 are respectively connected to one end of the main body region 21 covering the two first surfaces 11, close to the first facet, and the second folded ear 222 is connected to one end of the main body region 21 covering the second surface 12, close to the first facet. Each first folded ear 221 has a folded portion 2211.

[0096] In the second tail region, two of the three folded ears in the second tail region are configured as two first folded ears 221, and another of the three folded ears in the second tail region is configured as a second folded ear 222. The two first folded ears 221 are respectively connected to one end of the main body region 21 covering the two first surfaces 11, close to the first facet, and the second folded ear 222 is connected to one end of the main body region 21 covering the second surface 12, close to the first facet. Each first folded ear 221 has a folded portion 2211.

[0097] In some examples, when the square shell 10 is wrapped with the insulating film 20 in a zigzag wrapping manner, the shell 10 includes two first surfaces 11, two second surfaces 12 and one third surface 13, the first surface 11 is the large surface among the circumferential side surfaces of the square shell 10, the second surface 12 is the small surface among the circumferential side surfaces of the square shell 10, and the third surface 13 is the bottom surface of the square shell 10.

[0098] The insulating film 20 has a tail region 22 and four folded ears. Specifically, the insulating film 20 first covers the two first surfaces 11 and the two second surfaces 12 along the circumference of the housing 10 to form a main region 21 and four folded ears. The four folded ears are folded toward the bottom surface to cover the bottom surface to form the tail region 22. The four folded ears are configured as two first folded ears 221 and two second folded ears 222. The two first folded ears 221 are respectively connected to the end of the main region 21 covering the two first surfaces 11, which is close to the bottom surface. The two second folded ears 222 are connected to the end of the main region 21 covering the two second surfaces 12, which is close to the bottom surface. Each first folded ear 221 has two folded portions 2211.

[0099] It should be noted that the present application is also applicable to other encapsulation methods, whose structures and working principles are similar to the above-mentioned circular encapsulation method and U-shaped encapsulation method, and will not be repeated here.

[0100] In the embodiments disclosed herein, the insulating film 20 is typically adhesive-coated on one side, that is, the insulating film 20 has an adhesive-backed surface. During the process of coating the battery cell 7 with the insulating film 20, the insulating film 20 is first attached to the first and second surfaces 11 and 12 of the outer shell 10 via the adhesive-backed surface to form a main body region 21. The portion of the insulating film 20 extending beyond the main body region 21 serves as a plurality of flaps, which are folded over and attached to the third surface 13 of the outer shell 10 via the adhesive-backed surface to form a tail region 22.

[0101] In the folded portion 2211, the portion of the first folded ear 221 adjacent to the second folded ear 222 is folded in half with the other portion of the first folded ear 221. That is, the adhesive backing surface of the portion of the first folded ear 221 adjacent to the second folded ear 222 is adhered to the adhesive backing surface of the other portion of the first folded ear 221, leaving the folded portion 2211 free of adhesive on both sides along its thickness. Consequently, a gap is created between the folded portion 2211 and the second folded ear 222. In the event of an abnormality such as electrolyte leakage or thermal runaway in the battery cell 7, a capillary effect may occur in the gap between the folded portion 2211 and the second folded ear 222. Electrolyte may enter the gap and, under the action of voltage, conduct electricity between the outer casing 10 and the housing, causing insulation failure and thus affecting the reliability of the battery cell 7.

[0102] The connector 30 is used to seal the gap between the folded portion 2211 and the second folded ear 222, thereby increasing the creepage distance between the housing 10 at the location of the folded portion 2211 and the external environment. This reduces the risk of electrolyte entering the gap and conducting electricity between the housing 10 and the casing under the action of voltage in the event of an abnormality such as electrolyte leakage or thermal runaway in the battery cell 7.

[0103] Illustratively, in the process of folding the first fold ear 221 and the second fold ear 222 to form the tail area 22, the second fold ear 222 is first folded in the direction toward the third surface 13 so that the second fold ear 222 is attached to the third surface 13 in a flat form, and at the same time, a folding portion 2211 is formed on the first fold ear 221; then, the connecting piece 30 is assembled; finally, the two first fold ears 221 are folded toward the third surface 13 to form the tail area 22.

[0104] It should be noted that the aforementioned assembly connector 30 may be in various forms. For example, the connector 30 may be attached to the folded portion 2211, attached to the second folded ear 222 at a position corresponding to the folded portion 2211, or attached to the inner side of the entire first folded ear 221. Any form of the connector 30 may be sufficient as long as at least a portion of the connector 30 can be connected between the folded portion 2211 and the second folded ear 222.

[0105] The connector 30 may be directly connected to the insulating film 20 or may be secured to the insulating film 20 via other components. Optionally, the connector 30 may be, but is not limited to, double-sided tape or glue. The double-sided tape may be, but is not limited to, foam double-sided tape, substrate-free double-sided tape, polyethylene terephthalate double-sided tape, non-woven fabric double-sided tape, or paper-based double-sided tape. The glue may be, but is not limited to, made of polyvinyl alcohol, cyanoacrylate, epoxy resin, polyurethane, light-curing resin, silicone, acrylate, or the like.

[0106] The above technical solution provides a connector 30, at least part of which is connected between the folding portion 2211 and the second folding ear 222, so as to reduce or eliminate the gap between the folding portion 2211 and the second folding ear 222, thereby increasing the creepage distance between the outer shell 10 at the position where the folding portion 2211 is located and the external environment, thereby reducing the risk of insulation failure when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell 7, thereby improving the reliability of the battery cell 7.

[0107] In addition, most or all of the connector 30 in the embodiment of the present application can be covered by the insulating film 20. In other words, most or all of the connector 30 is not exposed outside the battery cell 7, which is beneficial to improving the consistency and appearance quality of the battery cell 7.

[0108] In some embodiments, at least a portion of the folded edge 2212 of the folded portion 2211 is exposed on the side of the second folded ear 222 facing away from the third surface 13. The folded edge 2212 exposed on the side of the second folded ear 222 facing away from the third surface 13 has a first projection on the third surface 13 along a direction perpendicular to the third surface 13, and the connecting member 30 connected between the folded portion 2211 and the second folded ear 222 has a second projection on the third surface 13 along a direction perpendicular to the third surface 13, and the first projection is located within the second projection.

[0109] Exemplarily, the fold edge 2212 of the fold portion 2211 refers to the edge where the fold line of the fold portion 2211 is located. For example, when the portion of the first fold ear 221 near the second fold ear 222 is folded in half with another portion of the first fold ear 221 to form the fold portion 2211, the location of the fold line formed by folding the portion of the first fold ear 221 near the second fold ear 222 and the other portion of the first fold ear 221 is the fold edge 2212. The fold edge 2212 of the fold portion 2211 can be partially exposed on the side of the second fold ear 222 facing away from the third surface 13, with the other portion covered by other portions of the insulating film 20; or the fold edge 2212 of the fold portion 2211 can be completely exposed on the side of the second fold ear 222 facing away from the third surface 13.

[0110] The first projection being within the second projection means that the connector 30 can connect the fold edge 2212 exposed on the side of the second fold ear 222 facing away from the third surface 13 to the second fold ear 222. In other words, the fold edge 2212 exposed on the side of the second fold ear 222 facing away from the third surface 13 is connected to the second fold ear 222 via the connector 30, thereby sealing the gap between the fold edge 2212 exposed on the side of the second fold ear 222 facing away from the third surface 13 and the second fold ear 222.

[0111] The fold edge 2212 of the folding portion 2211 is the place closest to the external environment from the gap between the folding portion 2211 and the second fold ear 222. The fold edge 2212 exposed on the side surface of the second fold ear 222 facing away from the third surface 13 can be understood as the entrance for the electrolyte to enter the gap. Therefore, this entrance is closed, that is, the gap between the fold edge 2212 exposed on the side surface of the second fold ear 222 facing away from the third surface 13 and the second fold ear 222 is sealed, so that when the battery cell 7 has abnormalities such as electrolyte leakage or thermal runaway, the electrolyte can be blocked outside and the electrolyte can be blocked from entering the gap.

[0112] The connector 30 of the above technical solution can connect the fold edge 2212 exposed on the side surface of the second fold ear 222 facing away from the third surface 13 with the second fold ear 222, so as to cut off the conductive relationship between the gap between the folded portion 2211 and the second fold ear 222 and the external environment, thereby reducing the blocking of electrolyte from entering the gap when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell 7, and further reducing the risk of insulation failure, thereby improving the reliability of the battery cell 7.

[0113] In some embodiments, the folded portion 2211 has a third projection on the third surface 13 along a direction perpendicular to the third surface 13 , and the third projection coincides with the second projection.

[0114] For example, the third projection coincides with the second projection, which can also be understood as follows: the third projection of the folded portion 2211 on the third surface 13 along a direction perpendicular to the third surface 13 is located within the second projection of the connector 30 on the third surface 13 along a direction perpendicular to the third surface 13. In other words, the connector 30 can connect the entire folded portion 2211 to the second folded ear 222. In other words, the entire folded portion 2211 is connected to the second folded ear 222 via the connector 30.

[0115] The connector 30 of the above technical solution can seal the gap between the entire folded portion 2211 and the second folded ear 222 , thereby further reducing the risk of insulation failure when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell 7 .

[0116] In some embodiments, the connector 30 is contoured, with the structural shape of the connector 30 matching that of the folding portion 2211. The number of connectors 30 matches the number of folding portions 2211, and the connector 30 is disposed on the inner side of the entire folding portion 2211. In other words, the connector 30 is disposed on the side of the entire folding portion 2211 facing the third surface 13. As an example, there are four folding portions 2211 and four connectors 30, and the four connectors 30 are disposed in a one-to-one correspondence with the four folding portions 2211.

[0117] In some embodiments, the connector 30 is contoured, with the structural shape of the connector 30 matching that of the first folded ears 221. The number of connectors 30 matches the number of first folded ears 221, and the connector 30 connects the inner side of the entire first folded ear 221. In other words, the connector 30 is disposed on the side of the entire first folded ear 221 facing the third surface 13. As an example, there are four first folded ears 221 and four connectors 30, and the four connectors 30 are disposed in a one-to-one correspondence with the four first folded ears 221.

[0118] In some embodiments, the connector 30 is an integral membrane-like structure. During the process of folding the first and second folded ears 221 and 222 to form the tail region 22, the second folded ear 222 is first folded toward the third surface 13 so that the second folded ear 222 is flatly attached to the third surface 13. At the same time, a folded portion 2211 is formed on the first folded ear 221. The connector 30 is then disposed on at least one of the third surface 13, the side of the second folded ear 222 facing away from the third surface 13, and the inner side of the first folded ear 221. Finally, the two first folded ears 221 are folded toward the third surface 13 to form the tail region 22. The specific location of the connector 30 can be varied, as long as at least a portion of the connector 30 can be connected between the folded portion 2211 and the second folded ear 222.

[0119] In some embodiments, the first folded ear 221 covers the connecting piece 30 .

[0120] Exemplarily, the connector 30 is located on a side of the first folded ear 221 close to the third surface 13. In other words, the projection of the connector 30 on the third surface 13 along a direction perpendicular to the third surface 13 is located within the projection of the first folded ear 221 on the third surface 13 along a direction perpendicular to the third surface 13. This prevents the connector 30 from being exposed outside the battery cell 7.

[0121] The above technical solution can not only reduce the risk of the connector 30 absorbing impurities, but also improve the consistency and appearance quality of the battery cell 7 .

[0122] In some embodiments, the outer surface of the housing 10 includes two third surfaces 13. The two first surfaces 11 are arranged opposite each other along a first direction X, and the two third surfaces 13 are arranged opposite each other along a second direction Y. Each third surface 13 connects the two first surfaces 11. The second surface 12 is located on one side of the housing 10 along a third direction Z and connects the first and third surfaces 11 and 13. The first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The main body region 21 includes two first sub-regions and a second sub-region. The two first sub-regions respectively cover the two first surfaces 11, and the second sub-region covers the second surface 12. The insulating film 20 includes two tail regions 22, and the two tail regions 22 respectively cover the two third surfaces 13. There are two connectors 30, and the two connectors 30 are respectively provided corresponding to the two tail regions 22.

[0123] Exemplarily, the housing 10 is a square housing 10, the two first surfaces 11 can be understood as the two large surfaces of the circumferential side surfaces of the housing 10, the second surface 12 can be understood as the bottom surface of the housing 10, and the two third surfaces 13 can be understood as the two small surfaces of the circumferential side surfaces of the housing 10. The insulating film 20 has two tail regions 22 and six folded ears, wherein each tail region 22 is formed by three folded ears.

[0124] As an example, the insulating film 20 may first cover a first surface 11 of the shell 10 to form a first sub-region, then the insulating film 20 may be folded toward the second surface 12 and cover the second surface 12 to form a second sub-region, and then the insulating film 20 may be folded toward another first surface 11 of the shell 10 to form another first sub-region and six folded ears, and then, three of the six folded ears may be folded toward one of the two third surfaces 13 to form a tail region 22, and the other three of the six folded ears may be folded toward the other of the two third surfaces 13 to form another tail region 22.

[0125] As another example, the insulating film 20 may first cover the second surface 12 of the shell 10 to form a second sub-area, and then the insulating film 20 is folded toward the two first surfaces 11 and covers the two first surfaces 11 to form two first sub-areas and six folded ears, and then, three of the six folded ears are folded toward one of the two third surfaces 13 to form a tail area 22, and the other three of the six folded ears are folded toward the other of the two third surfaces 13 to form another tail area 22.

[0126] The two connectors 30 are disposed in correspondence with the two end areas 22, respectively, meaning that one of the two connectors 30 is disposed in one of the two end areas 22, and the other of the two connectors 30 is disposed in the other of the two end areas 22. To further explain, one of the two connectors 30 is disposed in one of the two end areas 22, and the other of the two connectors 30 is disposed in the other of the two end areas 22.

[0127] The wrapping method adopted in the above technical solution enables the tail area 22 to be located on the side of the housing 10, thereby reducing the difficulty of setting the connector 30, which is beneficial to improving the production efficiency of the battery cell 7 and reducing the cost.

[0128] In some embodiments, each tail area 22 includes two first fold ears 221 and a second fold ear 222, the first fold ear 221 is connected to one end of the first sub-area close to the third surface 13, and the two first fold ears 221 located in the same tail area 22 are respectively folded relative to each other from the two first sub-areas toward the third surface 13, and the second fold ear 222 is connected to one end of the second sub-area close to the third surface 13, and is folded from the second sub-area toward the third surface 13.

[0129] For ease of description, the two third surfaces 13 are configured as the first facet and the second facet, respectively, and the two tail regions 22 are configured as the first tail region and the second tail region, respectively. Three of the six folded ears are connected to an end of the main body region 21 near the first facet and surround the periphery of the first facet. These three folded ears are folded toward the first facet to cover the first facet, forming the first tail region. Furthermore, the other three of the six folded ears are connected to an end of the main body region 21 near the second facet and surround the periphery of the second facet. These three folded ears are folded toward the second facet to cover the second facet, forming the second tail region.

[0130] In the first tail region, two of the three folded ears in the first tail region are configured as two first folded ears 221, and the other of the three folded ears in the first tail region is configured as a second folded ear 222. The two first folded ears 221 are respectively connected to the ends of the two first sub-regions near the first small face, and the second folded ear 222 is connected to the end of the second sub-region near the first small face. Each first folded ear 221 has a folded portion 2211.

[0131] In the second tail region, two of the three folded ears in the second tail region are configured as two first folded ears 221, and another of the three folded ears in the second tail region is configured as a second folded ear 222. The two first folded ears 221 are respectively connected to the ends of the two first sub-regions near the first small face, and the second folded ear 222 is connected to the end of the second sub-region near the first small face. Each first folded ear 221 has a folded portion 2211.

[0132] In some examples, the first folded ear 221 further has a notch, which is located near the second folded ear 222. The presence of the notch can further reduce the area of ​​the folded portion 2211 when the first folded ear 221 is affected by the folding of the second folded ear 222 to form the folded portion 2211.

[0133] The thickness of the folding portion 2211 of this wrapping method of the above technical solution is relatively small, that is, the number of layers of the insulating film 20 of the folding portion 2211 is relatively small. On the one hand, it is beneficial to reduce the overall volume of the battery cell 7 and can improve the energy density of the battery cell 7; on the other hand, since the thickness of the folding portion 2211 is relatively small, it can also reduce the degree of protrusion at the position where the connector 30 is located, thereby reducing the risk of interference between the connector 30 and other components around the battery cell 7.

[0134] In some embodiments, the connector 30 is integrally formed and includes a first connector 31 and two second connectors 32. The first connector 31 is connected to at least one of the third surface 13 and the second folded ears 222. In the second direction Y, the two side edges of the first connector 31 along the first direction X overlap with the two side edges of the third surface 13 along the first direction X. The two second connectors 32 are respectively connected to the two side edges of the first connector 31 along the first direction X, and the two second connectors 32 are respectively connected to the inner sides of the two first folded ears 221.

[0135] Exemplarily, the connector 30 is integrally provided, meaning that the connector 30 is integrally provided before connecting the folded portion 2211 and the second folded ear 222. In some examples, the connector 30 is an integrally provided film-like structure, wherein the film-like structure can be a double-sided tape.

[0136] In the process of folding the first fold ear 221 and the second fold ear 222 to form the tail area 22, the second fold ear 222 is first folded in the direction toward the third surface 13 so that the second fold ear 222 is attached to the third surface 13 in a flat form. At the same time, a folding portion 2211 is formed on the first fold ear 221; then, the first connecting portion 31 of the connecting member 30 is connected to the third surface 13 and at least one of the second fold ear 222, and the two second connecting portions 32 of the connecting member 30 are respectively connected to the inner sides of the two first fold ears 221; finally, the two first fold ears 221 are folded toward the third surface 13 to form the tail area 22.

[0137] The above technical solution can increase the layout area of ​​the connector 30, further increasing the creepage distance between the outside and the external environment, thereby further improving the reliability of the battery cell 7. In addition, the first connecting portion 31 connects the two second connecting portions 32, making the connector 30 an integrated structure, which can simplify the installation of the connector 30 and improve the overall production efficiency of the battery cell 7.

[0138] In some embodiments, two first folded ears 221 located in the same tail region 22 partially overlap.

[0139] For ease of description, the portion of the first folded ear 221 excluding the folded portion 2211 is configured as the bonding portion 2213. In other words, the portion of the first folded ear 221 that is not folded back upon itself is configured as the bonding portion 2213. The bonding portion 2213 comprises a single layer of insulating film 20. Two first folded ears 221 located in the same tail region 22 partially overlap, forming a stacked structure having multiple layers of insulating film in the tail region 22.

[0140] In some examples, in the same tail region 22, the fitting portions 2213 of the two first folded ears 221 partially overlap, and the folded portions 2211 of the two first folded ears 221 also partially overlap. In this way, a first stacking structure having two layers of insulating film, a second stacking structure having three layers of insulating film, and a third stacking structure having five layers of insulating film can be formed in the tail region 22. The first stacking structure is formed by the overlapping fitting portions 2213 of the two first folded ears 221, a portion of the second stacking structure is formed by the overlapping fitting portions 2213 of the two first folded ears 221 and the second folded ears 222, another portion of the second stacking structure is formed by the overlapping folded portions 2211 of each first folded ear 221 and the second folded ear 222, and the third stacking structure is formed by the overlapping folded portions 2211 of the two first folded ears 221 and the second folded ears 222.

[0141] In some examples, in the same tail region 22, the joining portions 2213 of the two first folded ears 221 partially overlap, while the folded portions 2211 of the two first folded ears 221 do not overlap. In this way, a first stacked structure having two layers of insulating film and a second stacked structure having three layers of insulating film can be formed in the tail region 22. The first stacked structure is formed by the overlapping joining portions 2213 of the two first folded ears 221, a portion of the second stacked structure is formed by the overlapping joining portions 2213 of the two first folded ears 221 and the second folded ears 222, and another portion of the second stacked structure is formed by the overlapping folded portions 2211 and the second folded ears 222 of each first folded ear 221.

[0142] The above technical solution can reduce the risk of incomplete coverage of the tail area 22 causing part of the outer surface of the shell 10 to be exposed to the external environment by partially overlapping the two first folded ears 221 located in the same tail area 22, thereby improving the coverage effect of the insulating film 20 and thus improving the reliability of the battery cell 7.

[0143] In some embodiments, the overlapping portion of the two first folded ears 221 located in the same tail area 22 has a fourth projection on the third surface 13 along the second direction Y, and the projection of the connecting member 30 along the second direction Y on the third surface 13 does not overlap with the fourth projection.

[0144] For example, the projection of the connector 30 along the second direction Y on the third surface 13 does not overlap with the fourth projection. This can also be understood as the connector 30 not being disposed in the overlapping portion of the two first folded ears 221 of the same tail region 22. In other words, the connector 30 is disposed away from the overlapping portion of the two first folded ears 221 of the same tail region 22.

[0145] It is understood that the connector 30 itself has a certain thickness, and the presence of the connector 30 increases the thickness of the insulating film 20 at the location where the connector 30 is provided. Moreover, the overlapping portion of the two first folded ears 221 in the same tail region 22 itself has a relatively large thickness.

[0146] In this way, the above technical solution can effectively reduce the overall thickness of the tail area 22, that is, reduce the maximum number of insulating film 20 layers in the tail area 22. On the one hand, it is beneficial to reduce the overall volume of the battery cell 7 and can improve the energy density of the battery cell 7; on the other hand, since the thickness of the folding portion 2211 is relatively small, it can also reduce the degree of protrusion at the position where the connector 30 is located, thereby reducing the risk of interference between the connector 30 and other components around the battery cell 7.

[0147] In some embodiments, the overlapping portion of the two first folded ears 221 located in the same tail area 22 has a fourth projection on the third surface 13 along the second direction Y, and the second connecting portion 32 has a fifth projection on the third surface 13 along the second direction Y, and the fourth projection and the fifth projection do not overlap.

[0148] Exemplarily, the fourth projection and the fifth projection do not overlap, which can also be understood as no second connection portion 32 being provided in the overlapping portion of the two first folded ears 221 of the same tail region 22. In other words, the second connection portion 32 is provided away from the overlapping portion of the two first folded ears 221 of the same tail region 22.

[0149] It is understood that the second connecting portion 32 of the connector 30 has a certain thickness, and the presence of the second connecting portion 32 increases the thickness of the insulating film 20 at the location where the second connecting portion 32 is provided. Moreover, the overlapping portion of the two first folded ears 221 in the same tail region 22 already has a relatively large thickness.

[0150] In this way, the above technical solution can effectively reduce the overall thickness of the tail area 22, that is, reduce the maximum number of insulating film 20 layers in the tail area 22. On the one hand, it is beneficial to reduce the overall volume of the battery cell 7 and can improve the energy density of the battery cell 7; on the other hand, since the thickness of the folding portion 2211 is relatively small, it can also reduce the degree of protrusion at the position where the second connecting portion 32 is located, thereby reducing the risk of interference between the position where the second connecting portion 32 is located and other components around the battery cell 7.

[0151] In some embodiments, the folded portions 2211 of the two first folded ears 221 located in the same tail region 22 do not overlap.

[0152] For ease of description, the portion of the first folded ear 221 excluding the folded portion 2211 is configured as the bonding portion 2213. In other words, the portion of the first folded ear 221 that is not folded back upon itself is configured as the bonding portion 2213. The bonding portion 2213 comprises a single layer of insulating film 20. Two first folded ears 221 located in the same tail region 22 partially overlap, forming a stacked structure having multiple layers of insulating film in the tail region 22.

[0153] In some examples, in the same tail region 22, the joining portions 2213 of the two first folded ears 221 partially overlap, while the folded portions 2211 of the two first folded ears 221 do not overlap. In this way, a first stacked structure having two layers of insulating film and a second stacked structure having three layers of insulating film can be formed in the tail region 22. The first stacked structure is formed by the overlapping joining portions 2213 of the two first folded ears 221, a portion of the second stacked structure is formed by the overlapping joining portions 2213 of the two first folded ears 221 and the second folded ears 222, and another portion of the second stacked structure is formed by the overlapping folded portions 2211 and the second folded ears 222 of each first folded ear 221.

[0154] In some examples, in the same tail region 22, the joining portions 2213 of two first folded ears 221 do not overlap, and the folded portions 2211 of two first folded ears 221 do not overlap. In this way, a first stacked structure having two layers of insulating film and a second stacked structure having three layers of insulating film can be formed in the tail region 22. The first stacked structure is formed by the overlapping joining portions 2213 of each first folded ear 221 and the second folded ear 222, and the second stacked structure is formed by the overlapping folded portions 2211 and the second folded ear 222 of each first folded ear 221.

[0155] The aforementioned technical solution has a relatively small thickness of the tail region 22, i.e., fewer layers of insulating film 20 in the tail region 22, which helps reduce the overall volume of the battery cell 7 and thereby improve the energy density of the battery cell 7. Furthermore, it provides a larger installation space for the connector 30, simplifying the installation of the connector 30 and thus improving the production efficiency of the battery cell 7 and reducing costs.

[0156] According to some embodiments of the present application, the present application further provides a battery, comprising a battery cell 7 according to any of the above solutions.

[0157] According to some embodiments of the present application, the present application further provides an electrical device, comprising a battery cell 7 according to any of the above solutions, wherein the battery cell 7 is used to provide electrical energy.

[0158] In order to better understand the battery cell 7 provided in the embodiment of the present application, based on the same inventive concept, an embodiment of the above-mentioned battery cell 7 in actual application is provided here for illustration.

[0159] An embodiment of the present application provides a battery cell 7, which includes a shell 10, an insulating film 20 and two connectors 30. The outer surface of the shell 10 includes two first surfaces 11, a second surface 12 and two third surfaces 13. The two first surfaces 11 are arranged opposite to each other along a first direction X, and the two third surfaces 13 are arranged opposite to each other along a second direction Y. Each third surface 13 connects the two first surfaces 11. The second surface 12 is located on one side of the shell 10 along the third direction Z and connects the first surface 11 and the third surface 13. The first direction X, the second direction Y and the third direction Z are perpendicular to each other.

[0160] The insulating film 20 is integrally formed and includes a main body region 21 and two tail regions 22. The main body region 21 includes two first sub-regions and a second sub-region. The two first sub-regions respectively cover the two first surfaces 11, and the second sub-region covers the second surface 12. The two tail regions 22 respectively cover the two third surfaces 13. Each tail region 22 includes multiple folded ears, which at least partially overlap. The multiple ears include a first folded ear 221 and a second folded ear 222. A portion of the first folded ear 221 is folded onto itself to form a folded portion 2211 having multiple layers of insulating film. The folded portion 2211 is stacked on the side of the second folded ear 222 facing away from the third surface 13. Two connectors 30 are provided corresponding to the two tail regions 22, with at least a portion of the connector 30 connected between the folded portion 2211 and the second folded ear 222.

[0161] The above technical solution provides a connector 30, at least part of which is connected between the folding portion 2211 and the second folding ear 222, so as to reduce or eliminate the gap between the folding portion 2211 and the second folding ear 222, thereby increasing the creepage distance between the outer shell 10 at the position where the folding portion 2211 is located and the external environment, thereby reducing the risk of insulation failure when abnormalities such as electrolyte leakage or thermal runaway occur in the battery cell 7, thereby improving the reliability of the battery cell 7.

[0162] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0163] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: a housing, wherein an outer surface of the housing includes two first surfaces, a second surface, and a third surface, the two first surfaces are arranged opposite to each other, the second surface connects the two first surfaces, the third surface connects the two first surfaces, and the first surface, the second surface, and the third surface intersect with each other; an insulating film integrally provided and comprising a main body region and a tail region, the main body region covering both the first surface and the second surface, the tail region covering the third surface and connecting to the main body region, the tail region comprising a plurality of folded ears, the plurality of folded ears at least partially overlapping, the plurality of folded ears comprising a first folded ear and a second folded ear, a portion of the first folded ear being folded upon itself to form a folded portion having multiple layers of the insulating film, the folded portion being laminated on a side of the second folded ear facing away from the third surface; A connecting member, at least a portion of which is connected between the folding portion and the second folding ear.

2. The battery cell according to claim 1, wherein: At least a portion of the folded edge of the folded portion is exposed on a side of the second folded ear facing away from the third surface; The fold edge exposed on the side surface of the second fold ear facing away from the third surface has a first projection on the third surface in a direction perpendicular to the third surface, and the connecting part connected between the folding portion and the second fold ear has a second projection on the third surface in a direction perpendicular to the third surface, and the first projection is located within the second projection.

3. The battery cell according to claim 2, characterized in that: The folded portion has a third projection on the third surface along a direction perpendicular to the third surface, and the third projection coincides with the second projection.

4. The battery cell according to claim 1, wherein: The first folding ear covers the connecting piece.

5. The battery cell according to claim 1, characterized in that The outer surface of the housing includes two third surfaces, the two first surfaces are arranged opposite to each other along a first direction, the two third surfaces are arranged opposite to each other along a second direction, each third surface connects two first surfaces, the second surface is located on one side of the housing along the third direction, and connects the first surface and the third surface, and the first direction, the second direction, and the third direction are perpendicular to each other; The main body region includes two first sub-regions and a second sub-region, the two first sub-regions respectively cover the two first surfaces, and the second sub-region covers the second surface; the insulating film includes two tail regions, and the two tail regions respectively cover the two third surfaces; The number of the connecting pieces is two, and the two connecting pieces are respectively arranged corresponding to the two finishing areas.

6. The battery cell according to claim 5, characterized in that Each of the tail areas includes two first fold ears and two second fold ears, the first fold ear is connected to one end of the first sub-area close to the third surface, the two first fold ears located in the same tail area are respectively folded relative to each other from the two first sub-areas toward the third surface, and the second fold ear is connected to one end of the second sub-area close to the third surface, and is folded from the second sub-area toward the third surface.

7. The battery cell according to claim 6, characterized in that The connecting member is integrally provided and includes a first connecting portion and two second connecting portions, the first connecting portion being connected to at least one of the third surface and the second folded ear, and in the second direction, two side edges of the first connecting portion along the first direction respectively overlap with two side edges of the third surface along the first direction; The two second connection parts are respectively connected to the two side edges of the first connection part along the first direction, and the two second connection parts are respectively connected to the inner sides of the two first folded ears.

8. The battery cell according to claim 7, characterized in that The two first folded ears located in the same tail region partially overlap.

9. The battery cell according to claim 8, characterized in that The overlapping parts of the two first folded ears located in the same tail area have a fourth projection on the third surface along the second direction, and the second connecting part has a fifth projection on the third surface along the second direction, and the fourth projection and the fifth projection do not overlap.

10. The battery cell according to claim 6, characterized in that The folded portions of the two first fold ears located in the same tail region do not overlap.

11. A battery, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 10.

12. An electrical device, characterized in that: The battery cell comprises the battery cell according to any one of claims 1 to 10, wherein the battery cell is used to provide electrical energy.

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