Battery cell, battery device, and electric device

Abstract

The present application discloses a battery cell, a battery device, and an electric device. The battery cell comprises a casing, an electrode assembly, an insulating sheet, and an insulating film. The casing comprises a housing and an end cover. The housing is provided with an opening, the end cover covers the opening, and the end cover and the housing define an accommodating cavity. The electrode assembly is arranged in the accommodating cavity. The insulating sheet is arranged on the side of the end cover distant from the accommodating cavity and attached to the end cover. The insulating film comprises a main body portion and a bent portion, the main body portion covers the housing from the outside, and the bent portion is connected to one end of the main body portion and bent relative to the main body portion. In the thickness direction of the end cover, at least part of the bent portion is located on the side of the insulating sheet facing away from the end cover. The technical solution of the present application can improve the insulating performance of the battery cell, reduce the risk of a short circuit between two adjacent battery cells, and improve the operational stability of the battery device.

Description

Battery cells, battery devices and electrical equipment Technical Field

[0001] This application relates to the field of batteries, and in particular to a battery cell, a battery device, and an electrical appliance. Background Technology

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

[0003] The development of battery technology must take into account multiple design factors. Improving the stability of a single battery cell during operation is a research direction in the battery field. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device, which can improve the insulation performance of the battery cell, reduce the risk of short circuit between two adjacent battery cells, and improve the operational stability of the battery device.

[0005] In a first aspect, this application provides a battery cell, including a casing, an electrode assembly, an insulating sheet, and an insulating film. The casing includes a housing and an end cap. The housing has an opening, and the end cap closes to the opening, forming a receiving cavity with the housing. The electrode assembly is disposed in the receiving cavity. The insulating sheet is disposed on the side of the end cap away from the receiving cavity and attached to the end cap. The insulating film includes a main body and a bent portion, the main body covering the housing from the outside, and the bent portion connected to one end of the main body and bent relative to the main body. In the thickness direction of the end cap, at least a portion of the bent portion is located on the side of the insulating sheet opposite to the end cap.

[0006] In the technical solution of this application embodiment, a housing is provided to accommodate the electrode assembly, reducing damage to the electrode assembly from external moisture or impurities, providing a stable spatial environment for the operation of the electrode assembly, and improving the operational stability of the battery cell. An opening is provided on the housing to facilitate the assembly of the electrode assembly, and an end cap closes the opening to improve the sealing performance of the housing. An insulating sheet is used to insulate the end cap from other components, and the main body of the insulating film surrounds the housing and part of the end cap to insulate the housing. Furthermore, the bent portion of the insulating film extends to the side of the insulating sheet opposite to the end cap, enabling it to cooperate with the insulating sheet to insulate the end cap, extending the creepage distance between the end cap and adjacent components, and improving the insulation performance of the battery cell.

[0007] In some embodiments, the bend covers the outer periphery of the insulating sheet in the thickness direction. The bend covers the periphery of the insulating sheet to form a closed boundary, effectively extending the creepage distance at various points on the end cap and reducing the risk of short circuit between the end cap and the outside world.

[0008] In some embodiments, the bending portion includes a first portion and a second portion disposed opposite each other along a first direction, and a third portion and a fourth portion disposed along a second direction, wherein the first direction, the second direction, and the thickness direction are perpendicular to each other, and the first portion, the third portion, the second portion, and the fourth portion are connected end-to-end in sequence. In the above structure, the four portions of the bending portion are connected in sequence and perpendicular to each other, resulting in a regular structure that is easy to assemble. Therefore, the above structure makes the insulation performance of each portion similar, improving the insulation performance of the entire end cap.

[0009] In some embodiments, the first portion and the third portion partially overlap in the thickness direction. In the above structure, the overlap between two adjacent portions further improves the insulation performance at the connection between the two adjacent portions and reduces the risk of short circuits at the corners of the end cap.

[0010] In some embodiments, the main body is wound around the outside of the housing. The main body includes a winding start end and a winding tail end disposed opposite each other along the winding direction. A portion of the main body is located between the winding tail end and the housing to form an overlapping area. In the above structure, the main body is wound around the outside of the housing, completely covering the housing and improving the insulation performance of the housing. Furthermore, the overlapping area formed by the winding tail end and the start end enhances the connection strength between the main body and the housing, reducing the risk of displacement or detachment of the main body.

[0011] In some embodiments, the housing includes two first walls disposed opposite each other along a first direction and two second walls disposed opposite each other along a second direction. The area of ​​the first walls is smaller than the area of ​​the second walls. An overlapping region is disposed on the first walls, and the first direction, the second direction, and the thickness direction intersect each other perpendicularly. In the above structure, disposing of the overlapping region on a small side of the housing can reduce the risk of interference with adjacent battery cells and effectively utilize the space on the side of the housing, thereby improving space utilization.

[0012] In some embodiments, along the thickness direction of the battery cell, the width of the orthographic projection of the bent portion onto the insulating sheet is D1, and the width of the end cap is D2, where D1 and D2 satisfy: 0.05 ≤ D1 / D2 ≤ 0.2. Limiting the ratio of the bent portion width to the end cap width to greater than or equal to 0.05 restricts the minimum width of the bent portion, ensuring that the bent portion has basic insulation performance. Limiting the ratio of the bent portion width to the end cap width to less than or equal to 0.2 limits the space occupied by the bent portion and reduces the risk of interference between the bent portion and other components on the end cap.

[0013] In some embodiments, the insulating sheet includes an insulating base layer and an adhesive layer. The insulating base layer is disposed on the side of the end cap opposite to the electrode assembly. The adhesive layer is disposed between the end cap and the insulating base layer, and bonds the insulating base layer to the end cap. In this structure, the insulating base layer, through the adhesive layer, improves the connection strength with the insulating sheet. The insulating base layer forms good insulation between the end cap and other components, improving the insulation performance of the battery cell.

[0014] In some embodiments, the battery cell further includes electrode terminals disposed on an end cap, at least a portion of which protrudes from the surface of the end cap opposite to the electrode assembly; the insulating sheet has through holes, and the electrode terminals are disposed within the through holes. This structure, with the electrode terminals protruding from the surface of the end cap, facilitates connection between the electrode terminals and other components to deliver electrical energy. The through holes in the insulating sheet for accommodating the electrode terminals improve the positional accuracy and installation efficiency of the insulating sheet assembly.

[0015] In some embodiments, along the thickness direction of the battery cell, the width of the orthographic projection of the electrode terminal on the end cap is D3, where D3 and D2 satisfy: 0.1 ≤ D3 / D2 < 0.9. Limiting D3 / D2 to greater than 0.1 provides space for the electrode terminal arrangement. Limiting D3 / D2 to less than 0.9 provides space for the bending portion, reducing the risk of interference between the electrode terminal and the bending portion, and improving the connection stability between the bending portion and the insulating sheet.

[0016] In some embodiments, two end caps are provided on opposite sides of the housing along a third direction. Two insulating sheets and two bends are correspondingly provided. The two bends are connected to the two ends of the main body along the third direction and to the two insulating sheets. The third direction intersects the plane containing the first and second directions. In the above technical solution, placing the positive and negative terminals at opposite ends of the housing reduces the risk of short circuits between the positive and negative terminals. The two bends provide good insulation for both the positive and negative terminals, improving the overall insulation performance of the battery cell.

[0017] In some embodiments, the end cap has a recess on the surface opposite to the electrode assembly, and at least a portion of the insulating sheet is accommodated within the recess. In the above structure, the recess design can make more efficient use of the battery casing space and reduce the risk of interference between the insulating sheet and other components.

[0018] In some embodiments, the surface of the insulating sheet facing away from the electrode assembly is flush with the upper surface of the end cap edge. In this structure, the insulating sheet is fully embedded within the recess, and its outer surface is flush with the upper surface of the end cap. This design ensures tight contact between the insulating sheet and the battery end cap, reducing gaps and thus improving insulation performance.

[0019] In some embodiments, a gap is provided between the insulating sheet and the outer peripheral edge of the end cap, and the insulating film covers the gap. The above technical solution, by covering the gap between the insulating sheet and the end cap with the insulating film, reduces the risk of short circuit leakage at the gap and improves the insulation performance of the battery cell.

[0020] Secondly, this application provides a battery device that includes the battery cell described in the above embodiments.

[0021] Thirdly, this application provides an electrical device that includes the battery device described in the above embodiments, the battery device being used to provide electrical energy.

[0022] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0023] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0024] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0025] Figure 2 is an exploded schematic diagram of a battery device provided in some embodiments of this application;

[0026] Figure 3 is an exploded schematic diagram of a battery cell provided in some embodiments of this application;

[0027] Figure 4 is a schematic diagram of the structure of a battery cell provided in some other embodiments of this application;

[0028] Figure 5 is a structural schematic diagram of section AA in Figure 4;

[0029] Figure 6 is an enlarged structural diagram of part B in Figure 5;

[0030] Figure 7 is a schematic diagram of the structure of the end cap of the battery device provided in some embodiments of this application;

[0031] Figure 8 is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0032] Figure 9 is a schematic diagram of the end cap structure of a battery device provided in some other embodiments of this application;

[0033] Figure 10 is an enlarged structural diagram of part C in Figure 8.

[0034] Detailed Explanation of Reference Numerals in the Drawings: 1. Vehicle; 2. Battery Unit; 3. Controller; 4. Motor; 5. Housing; 5a. First Housing Section; 5b. Second Housing Section; 5c. Receiving Space; 6. Battery Cell; 20. Outer Shell; 21. Housing; 22. End Cap; 23. Gap; 30. Insulating Sheet; 31. Insulating Base Layer; 32. Adhesive Layer; 40. Insulating Film; 41. Main Body Section; 42. Bending Section; 43. First Part; 44. Second Part; 45. Third Part; 46. Fourth Part; 47. Overlapping Part; 48. Overlapping Area; 50. Electrode Terminal; X. First Direction; Y. Second Direction; Z. Thickness Direction. Detailed Implementation

[0035] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0037] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0038] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0039] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0040] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0041] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0042] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0043] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0044] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0045] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 85°-90°, the two directions can be considered perpendicular; if the angle between two directions is 0°-5°, the two directions can be considered parallel.

[0046] In this application, "multiple" means two or more (including two).

[0047] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0048] The battery cell can be a lithium-ion battery, sodium-ion battery, sodium-lithium-ion battery, lithium metal battery, sodium metal battery, lithium-sulfur battery, magnesium-ion battery, nickel-metal hydride battery, nickel-cadmium battery, lead-acid battery, etc., and the embodiments of this application are not limited to this.

[0049] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the positive and negative electrodes. During the charging and discharging process of a single battery cell, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, prevents short circuits while allowing active ions to pass through.

[0050] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0051] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0052] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0053] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as battery positive electrode active materials may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3 Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.8 Co 0.15 Al 0.05 At least one of O2 and its modified compounds. Modified compounds refer to substances obtained by modification methods such as doping or coating based on the above-mentioned substances.

[0054] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0055] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0056] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0057] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0058] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0059] In some embodiments, the negative electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloy, or foamed carbon, etc. When foamed metal is used as the negative electrode sheet, the surface of the foamed metal may or may not have a negative electrode active material.

[0060] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0061] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0062] In some embodiments, the electrode assembly further includes an isolator disposed between the positive and negative electrodes.

[0063] In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous separator membrane with good chemical and mechanical stability can be selected.

[0064] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be applied to the surface of the separator.

[0065] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0066] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0067] Liquid electrolytes include electrolyte salts and solvents.

[0068] In some embodiments, the electrolyte salt may be selected from at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0069] In some embodiments, the solvent may be selected from at least one of ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more of ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0070] In some embodiments, the electrolyte may optionally include additives. For example, additives may include negative electrode film-forming additives, positive electrode film-forming additives, and additives that can improve certain properties of the battery cell, such as additives that improve the overcharge / fast charge performance of the battery cell, additives that improve the high-temperature performance of the battery cell, and additives that improve the low-temperature performance of the battery cell.

[0071] The gel electrolyte includes a polymer as a backbone network and can be used in conjunction with an ionic liquid—lithium salt.

[0072] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0073] As an example, the polymers of polymeric solid electrolytes may include polyethers (polyoxyethylene), polysiloxanes, polycarbonates, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids, cellulose, etc.

[0074] As an example, inorganic solid electrolytes can be one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphorus sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0075] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0076] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0077] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0078] In some implementations, the electrode assembly is a stacked structure.

[0079] As an example, multiple positive and negative electrodes can be set, and multiple positive and multiple negative electrodes can be stacked alternately.

[0080] As an example, multiple positive electrode plates can be provided, and negative electrode plates can be folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0081] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0082] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0083] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0084] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0085] In some embodiments, the electrode assembly is provided with tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0086] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc. In some embodiments, the casing may be a sealed structure or a non-sealed structure. As an example, when the casing is a non-sealed structure, the casing serves to protect the electrode assembly, and a sealing bag is included between the casing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing is a sealed structure, it is used to encapsulate components such as the electrode assembly and electrolyte.

[0087] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0088] In some embodiments, the housing includes an end cap and a housing, the housing having an opening, and the end cap covering the opening. The housing may have one or more openings. The end cap may also have one or more.

[0089] In some embodiments, at least one electrode terminal is provided on the housing, and the electrode terminal is electrically connected to the tab. The electrode terminal can be directly connected to the tab, or it can be indirectly connected to the tab through a current collector. The electrode terminal can be provided on the end cap or on the housing.

[0090] To improve the insulation performance of individual battery cells, an insulating film is typically placed around the cell, wrapping the casing and extending its edges to the end cap, where it adheres to the end cap surface to form a stable connection. Additionally, an insulating sheet is also placed on the end cap to insulate it. In related technologies, a portion of the insulating sheet covers the side of the insulating film facing away from the end cap. However, with this structure, the creepage distance between adjacent battery cells is insufficient, making short-circuit accidents more likely.

[0091] In view of this, this application provides a technical solution by setting a shell to accommodate the electrode assembly, reducing damage to the electrode assembly from external moisture or impurities, providing a stable spatial environment for the operation of the electrode assembly, and improving the operational stability of the battery cell. An opening is provided on the shell to facilitate the assembly of the electrode assembly, and an end cap closes the opening to improve the sealing performance of the shell. An insulating sheet is used to insulate the end cap from other components, and the main body of the insulating film surrounds the shell and part of the end cap to insulate the shell. Furthermore, the bent portion of the insulating film extends to the side of the insulating sheet opposite to the end cap, enabling it to cooperate with the insulating sheet to insulate the end cap, extending the creepage distance between the end cap and adjacent components, and improving the insulation performance of the battery cell.

[0092] The battery apparatus mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells connected in series, parallel, or mixed connections via a busbar.

[0093] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0094] As an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells together to form an independent module. As another example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0095] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cells housed within the housing.

[0096] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be housed in the housing by fixing the battery module in the housing.

[0097] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0098] As an example, the enclosure may include a first enclosure and a second enclosure. The first enclosure and the second enclosure are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first enclosure may be a top cover or a bottom plate.

[0099] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0100] In some embodiments, the housing may be part of the vehicle's chassis structure. For example, a portion of the housing may be at least a part of the vehicle's floor, or a portion of the housing may be at least a part of the vehicle's crossbeams and longitudinal beams.

[0101] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use individual battery cells, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships, and spacecraft. For example, spacecraft include airplanes, rockets, space shuttles, and spacecraft.

[0102] Electrical devices can include vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and power tools, etc. Vehicles can be gasoline-powered cars, natural gas-powered cars, or new energy vehicles; new energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. This application does not impose any special limitations on the above-mentioned electrical devices.

[0103] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0104] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0105] As shown in Figure 1, a battery 2 is installed inside the vehicle 1. The battery 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0106] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0107] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0108] Figure 2 is an exploded view of a battery provided in some embodiments of this application. As shown in Figure 2, the battery device 2 includes a housing 5 and a battery cell 6, with the battery cell 6 housed within the housing 5. The battery cell 6 can be the smallest unit that makes up the battery.

[0109] The housing 5 is used to house the battery cell 6, and the housing 5 can have various structures. In some embodiments, the housing 5 may include a first housing portion 5a and a second housing portion 5b, which overlap each other, and together define a housing space 5c for housing the battery cell 6. The second housing portion 5b may be a hollow structure with one end open, and the first housing portion 5a may be a plate-like structure, with the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c; alternatively, both the first housing portion 5a and the second housing portion 5b may be hollow structures with one side open, with the open side of the first housing portion 5a covering the open side of the second housing portion 5b to form a housing 5 with the housing space 5c. Of course, the first housing portion 5a and the second housing portion 5b can be various shapes, such as cylinders, cuboids, etc.

[0110] To improve the sealing performance after the first housing part 5a and the second housing part 5b are connected, a sealing element, such as sealant or sealing ring, can also be provided between the first housing part 5a and the second housing part 5b.

[0111] Assuming that the first box section 5a covers the top of the second box section 5b, the first box section 5a can also be called the upper box cover, and the second box section 5b can also be called the lower box.

[0112] In the battery device 2, there can be one or more battery cells 6. If there are multiple battery cells 6, they can be connected in series, in parallel, or in a mixed manner. A mixed connection means that multiple battery cells 6 are connected in both series and parallel.

[0113] Multiple battery cells 6 can be directly connected in series, parallel, or in a mixed manner, and then the whole composed of multiple battery cells 6 can be housed in the housing 5; of course, multiple battery cells 6 can also be connected in series, parallel, or in a mixed manner to form a battery module, and multiple battery modules can then be connected in series, parallel, or in a mixed manner to form a whole, and housed in the housing 5.

[0114] Figure 3 is an exploded schematic diagram of a battery cell provided in some embodiments of this application.

[0115] The battery cell 6 includes a housing 20 and an electrode assembly housed within the housing 20. There may be one or more battery cells 6.

[0116] The outer casing 20 is a hollow structure, with an internal space for accommodating the electrode assembly. The shape of the outer casing 20 can be determined according to the specific shape of the electrode assembly. For example, if the electrode assembly is a cuboid structure, a cuboid outer casing can be used.

[0117] As an example, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening and the end cap 22 for closing the opening.

[0118] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 6. The formed internal cavity can be used to accommodate the electrode assembly, electrolyte, and other components.

[0119] The housing 21 and the end cap 22 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for the battery cell 6.

[0120] The housing 21 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly. The material of the housing 21 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc., and this application embodiment does not impose any special limitations on this.

[0121] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.), so that the end cap 22 is not easily deformed when subjected to compression and impact, so that the battery cell 6 can have higher structural strength and improve reliability.

[0122] The end cap 22 is connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0123] The housing 21 may be open at one end or at both ends. In some examples, the housing 21 may be open on one side, with one end cap 22 covering the housing 21. In other examples, the housing 21 may be open on both sides, with two end caps 22 covering the two openings of the housing 21 respectively. The electrode assembly is the component in the battery cell 6 where the electrochemical reaction takes place.

[0124] Please refer to Figures 3 to 6. Figure 3 is an exploded view of a battery cell provided in some embodiments of this application. Figure 4 is a structural diagram of a battery cell provided in other embodiments of this application. Figure 5 is a structural diagram of section AA in Figure 4. Figure 6 is a structural diagram of section B in Figure 5.

[0125] As shown in the figure, an embodiment of this application provides a battery cell 6, including a housing 20, an electrode assembly, an insulating sheet 30, and an insulating film 40. The housing 20 includes a shell 21 and an end cap 22. The shell 21 has an opening, and the end cap 22 closes to the opening, forming a receiving cavity with the shell 21. The electrode assembly is disposed in the receiving cavity. The insulating sheet 30 is disposed on the side of the end cap 22 away from the receiving cavity and attached to the end cap 22. The insulating film 40 includes a main body portion 41 and a bent portion 42. The main body portion 41 covers the shell 21 from the outside, and the bent portion 42 is connected to one end of the main body portion 41 and bent relative to the main body portion 41. In the thickness direction Z of the end cap 22, at least a portion of the bent portion 42 is located on the side of the insulating sheet 30 facing away from the end cap 22.

[0126] The attachment connection method refers to attaching and connecting the insulating sheet 30 to the surface of the end cap 22. This can be done by bonding, welding, or using fasteners, or by directly coating the end cap 22 with insulating material, which is then cooled and molded to form the insulating sheet 30. The attachment connection method offers high connection strength and stability, providing excellent insulation protection for the end cap 22.

[0127] The main body 41 covers the housing 21 from the outside, which can completely cover the side of the housing 21 away from the electrode assembly, reducing the risk of leakage due to the exposed housing 21.

[0128] The bending portion 42 bends relative to the main body portion 41, meaning that the bending portion 42 and the main body portion 41 form a certain angle. For example, the angle can be approximately 90° to better fit the outer shell 20.

[0129] The bending portion 42 can be continuously arranged around the outer perimeter of the insulating sheet 30, or multiple portions can be interconnected and arranged around it. Alternatively, the bending portion 42 can partially cover the insulating sheet 30.

[0130] The bent portion 42 can be formed by bonding, welding, or directly coating the insulating sheet 30. Alternatively, the bent portion 42 may not be directly connected to the insulating sheet 30; after the end cap 22 completes its assembly connection with the housing 21, the end cap 22 applies pressure to the bent portion 42, pressing it against the surface of the insulating sheet 30. Preferably, the bent portion 42 is bonded to the insulating sheet 30.

[0131] For example, the insulating sheet 30 needs to have good corrosion resistance, thermal stability, and insulation properties. The insulating sheet 30 and the end cap 22 can be connected by adhesive bonding.

[0132] The insulating film 40 can be a polyethylene terephthalate (PET) film or a polyolefin film. These materials possess good insulation properties, thermal stability, corrosion resistance, and a certain degree of mechanical strength. The bent portion 42 of the insulating film 40 is fitted and fixedly connected to the end cap 22 and the insulating sheet 30.

[0133] For example, the step of wrapping the insulating film 40 onto the housing 20 may include: placing the insulating sheet 30 on the end cap 22; rolling the insulating film 40 along the outside of the housing 21 and completely wrapping the housing 21; overlapping the first and last ends of the insulating film 40 and heat-pressing the overlapping area together; bending the insulating film 40 along the edge of the end cap 22 to fit with the end cap 22 and the insulating sheet 30; and then heat-pressing the blue film on the long side of the end cap 22 and folding it again to complete the entire wrapping process.

[0134] In the technical solution of this application embodiment, a housing 20 is provided to accommodate the electrode assembly, reducing damage to the electrode assembly from external moisture or impurities, providing a stable spatial environment for the operation of the electrode assembly, and improving the operational stability of the battery cell 6. An opening is provided on the housing 21 to facilitate the assembly of the electrode assembly, and the end cap 22 closes the opening to improve the sealing performance of the housing 20. An insulating sheet 30 is used to insulate the end cap 22 from other components, and the main body 41 of the insulating film 40 surrounds the housing 21 and part of the end cap 22 to insulate the housing 21. Furthermore, the bent portion 42 of the insulating film 40 extends to the side of the insulating sheet 30 facing away from the end cap 22, and can cooperate with the insulating sheet 30 to insulate the end cap 22, extending the creepage distance between the end cap 22 and adjacent components, and improving the insulation performance of the battery cell 6.

[0135] As shown in Figures 4 to 6, in some embodiments of this application, the bent portion 42 covers the outer periphery of the insulating sheet 30 in the thickness direction Z.

[0136] The design of the bend 42 allows the insulating film 40 to not only cover the main part of the housing 21 but also extend further to the outer periphery of the insulating sheet 30. This creates a continuous, seamless insulating layer between the bend 42 and the insulating sheet 30. By covering the periphery of the insulating sheet 30, the bend 42 creates a closed insulating boundary. This boundary effectively isolates the end cap 22 from the external environment, reducing the possibility of moisture, dust, and other impurities entering the battery.

[0137] Creepage distance refers to the shortest distance measured along the surface of an insulating material from a high-voltage section to a low-voltage section or a grounded section. In this application, the shortest creepage distance refers to the shortest distance along the surface of the end cap 22 of one battery cell 6 to the end cap 22 of another adjacent battery cell 6. The presence of the bend 42 significantly extends the creepage distance at various points on the end cap 22, thereby reducing the risk of short circuits due to surface discharge.

[0138] The bend 42 covers the periphery of the insulating sheet 30 to form a closed boundary, effectively extending the creepage distance at all points of the end cover 22 and reducing the risk of short circuit between the end cover 22 and the outside world.

[0139] As shown in FIG7, in some embodiments of this application, the bending portion 42 includes a first portion 43 and a second portion 44 disposed opposite to each other along the first direction X, a third portion 45 and a fourth portion 46 disposed along the second direction Y, the first direction X, the second direction Y and the thickness direction Z being perpendicular to each other, wherein the first portion 43, the third portion 45, the second portion 44 and the fourth portion 46 are connected end to end in sequence.

[0140] For example, the first part 43 and the second part 44 have the same shape, and the third part 45 and the fourth part 46 have the same shape. Moreover, the first part 43, the third part 45, the second part 44 and the fourth part 46 are all rectangular structures.

[0141] The four parts of the bend 42—part 43, part 45, part 44, and part 46—are connected end-to-end in sequence and perpendicular to each other, forming a regular structure. This structure is not only aesthetically pleasing but also facilitates manufacturing and assembly. Due to its regular structure, the bend 42 can be more easily assembled with the insulating sheet 30 and the end cap 22. This reduces the complexity and error rate in the assembly process and improves production efficiency.

[0142] Because the four sections of the bend 42 are structurally similar and perpendicular to each other, their insulation performance tends to be consistent. This helps ensure a uniform distribution of insulation performance throughout the end cover 22, thereby improving the overall safety of the battery cell 6. This structural design of the bend 42, by increasing the complexity and continuity of the insulation layer, effectively enhances the insulation performance of the entire end cover 22. This further reduces the safety risks caused by short circuits or discharges.

[0143] In the above structure, the four parts of the bending portion 42 are connected sequentially and perpendicular to each other, resulting in a neat structure that is easy to assemble. Therefore, the above structure makes the insulation performance of each part similar, improving the overall insulation performance of the end cap 22.

[0144] As shown in Figures 8 to 10, in some embodiments of this application, the first portion 43 and the third portion 45 partially overlap in the thickness direction Z.

[0145] Optionally, the second part 44 and the third part 45 partially overlap in the thickness direction Z; the second part 44 and the fourth part 46 partially overlap in the thickness direction Z; and the first part 43 and the fourth part 46 partially overlap in the thickness direction Z.

[0146] For example, the overlapping portion 47 is divided into overlapping portions 47. The overlapping portion 47 includes edge material of the first portion 43 and edge material of the second portion 44. The materials of these two portions are overlapped and then bent to the surface of the first portion 43 or the second portion 44, and fused with them by hot pressing. Therefore, the overlapping portion 47 has at least three layers of insulating film 40 material.

[0147] The overlap of the first part 43 and the third part 45 in the thickness direction Z provides an additional insulating layer at the connection. This increases the thickness and continuity of the insulating material, thereby improving the insulation performance of the area. The corners of the end cap 22 are often prone to short circuits because the insulation layer there may be thinner or defective. The overlapping design provides additional protection at the connection between adjacent parts, thus reducing the risk of short circuits in these areas.

[0148] Furthermore, the above-described structure reduces the shearing process of the insulating film 40, allowing it to be formed in a single hot pressing process, thereby improving the efficiency of hot pressing and enhancing the connection strength and stability between the insulating film 40, the insulating sheet 30, and the end cap 22.

[0149] In some embodiments of this application, the main body 41 is wound around the outside of the housing 21. The main body 41 includes a winding start end and a winding tail end disposed opposite to each other along the winding direction. A portion of the main body 41 is located between the winding tail end and the housing 21 to form an overlapping area 48.

[0150] The overlapping area 48 formed between the winding tail end and the housing 21 not only increases the thickness of the insulation layer but also enhances the connection strength between the main body 41 and the housing 21. This reduces the risk of the main body 41 shifting or detaching due to external factors such as vibration and impact. Through the overlapping area 48 and the winding design, a tight bond is formed between the main body 41 and the housing 21. This improves the stability of the entire structure, allowing the battery end cap 22 or the insulation layer to better withstand external pressure and impact.

[0151] The winding design makes it easier to assemble the main body 41 with the housing 21, and hot pressing can be performed in the overlapping area 48 to improve the connection strength. At the same time, the overlapping area 48 can serve as a positioning reference during assembly, which helps to improve the accuracy and efficiency of assembly.

[0152] In the above structure, the main body 41 is wound around the outside of the housing 21, completely covering the housing 21 and improving the insulation performance of the housing 21. Furthermore, the tail end and the head end of the wound portion form an overlapping area 48, which enhances the connection strength between the main body 41 and the housing 21 and reduces the risk of the main body 41 shifting or falling off.

[0153] As shown in Figure 8, in some embodiments of this application, the housing 21 includes two first walls disposed opposite each other along a first direction X and two second walls disposed opposite each other along a second direction Y. The area of ​​the first wall is smaller than the area of ​​the second wall. The overlapping area 48 is disposed on the first wall. The first direction X, the second direction Y and the thickness direction Z intersect each other perpendicularly.

[0154] In the battery assembly 2, the battery cells 6 are typically stacked along the second direction Y, meaning that the larger sides of two adjacent battery cells 6 are arranged opposite each other. Since the area of ​​the first wall is relatively small, placing the overlapping area 48 here reduces the risk of interference with adjacent battery cells 6. This is particularly important during battery module assembly, ensuring a tight arrangement and effective isolation between the individual battery cells 6.

[0155] In the above structure, the overlapping area 48 is set on the small side of the housing 21, which can reduce the risk of interference with the adjacent battery cell 6 and effectively utilize the space on the side of the housing 21, thereby improving space utilization.

[0156] As shown in Figure 7, in some embodiments of this application, along the thickness direction Z of the end cap 22, the width of the orthographic projection of the bent portion 42 onto the insulating sheet 30 is D1, and the width of the end cap 22 is D2. D1 and D2 satisfy: 0.05 ≤ D1 / D2 ≤ 0.2. Optionally, 0.1 ≤ D1 / D2 ≤ 0.2.

[0157] For example, the width range of D1 is: 3mm≤D1≤6mm, where D1 can be 3mm, 4mm, 5mm, or 6mm.

[0158] The width range of D2 is: 10mm≤D2≤30mm. D2 can be 10mm, 15mm, 20mm, 24mm, 26mm, 28mm, 29mm, or 30mm.

[0159] Limiting the ratio of the width of the bend 42 to the width of the end cap 22 to greater than or equal to 0.05 restricts the minimum width of the bend 42, ensuring that the bend 42 has basic insulation properties. Limiting the ratio of the width of the bend 42 to the width of the end cap 22 to less than or equal to 0.2 limits the space occupied by the bend 42 and reduces the risk of interference between the bend 42 and other components on the end cap 22.

[0160] As shown in Figure 3, in some embodiments of this application, the insulating sheet 30 includes an insulating base layer 31 and an adhesive layer 32. The insulating base layer 31 is disposed on the side of the end cap 22 opposite to the electrode assembly. The adhesive layer 32 is disposed between the end cap 22 and the insulating base layer 31, and adheres the insulating base layer 31 to the end cap 22.

[0161] In the above structure, the insulating base layer 31 is bonded to the insulating sheet 30 via the adhesive layer 32, thereby improving the connection strength with the insulating sheet 30. The insulating base layer 31 forms good insulation between the end cap 22 and other components, improving the insulation performance of the battery cell 6.

[0162] In some embodiments of this application, the battery cell 6 further includes an electrode terminal 50 disposed on the end cap 22, at least a portion of the end cap 22 protruding from the surface of the end cap 22 opposite to the electrode assembly. The insulating sheet 30 has a through hole, and the electrode terminal 50 is disposed within the through hole. Exemplarily, the insulating base layer 31 has a first hole, and the adhesive layer 32 has a second hole, the first hole and the second hole communicating with each other to form a through hole.

[0163] The electrode terminal 50 protrudes from the end cover 22 and faces away from the electrode assembly. This design makes it easier for the electrode terminal 50 to be connected to other components, such as the busbar and connector in the battery module, so as to facilitate the transmission of electrical energy.

[0164] The insulating sheet 30 has through holes corresponding to the electrode terminals 50. This design makes it easier to accurately position the electrode terminals 50 within the through holes during assembly. This not only improves the positional accuracy of the insulating sheet 30 during assembly but also avoids assembly difficulties or performance degradation caused by positional deviations.

[0165] By providing through holes in the insulating sheet 30 to mount the electrode terminals 50, the assembly process can be simplified and installation efficiency improved. The electrode terminals 50 are tightly bonded to the insulating sheet 30 and end cap 22 through the through holes; this design enhances the structural stability of the battery cell 6. This stability helps ensure that the battery maintains its performance and safety during long-term use.

[0166] The above structure allows the electrode terminal 50 to protrude from the surface of the end cap 22, facilitating its connection with other components for power transmission. The insulating sheet 30 has through holes for mounting the electrode terminal 50, and also improves the positioning accuracy and installation efficiency of the insulating sheet 30.

[0167] In some embodiments of this application, along the thickness direction Z of the end cap 22, the width of the orthographic projection of the electrode terminal 50 on the end cap 22 is D3, and D3 and D2 satisfy: 0.1≤D3 / D2<0.9.

[0168] Limiting D3 / D2 to greater than 0.1 provides space for the electrode terminal 50. Limiting D3 / D2 to less than 0.9 provides space for the bending portion 42, reduces the risk of interference between the electrode terminal 50 and the bending portion 42, and improves the connection stability between the bending portion 42 and the insulating sheet 30.

[0169] For example, the width range of D3 is: 3mm≤D1≤27mm, and D3 can be 3mm, 5mm, 7mm, 9mm, 15mm, 18mm, 19mm, or 20mm.

[0170] In some embodiments of this application, there are two end caps 22, which are disposed on opposite sides of the housing 21 along a third direction. Two insulating sheets 30 and two bending portions 42 are correspondingly provided. The two bending portions 42 are respectively connected to the two ends of the main body 41 along the third direction and are respectively connected to the two insulating sheets 30. The third direction intersects the plane containing the first direction X and the second direction Y. For example, the third direction is the same as the thickness direction Z of the end cap 22.

[0171] By placing the positive and negative terminals at opposite ends of the housing 21, this layout fundamentally reduces the risk of short circuits caused by improper physical contact or electrical connection between the positive and negative terminals. This design helps ensure that the battery cell 6 maintains its electrical performance and safety during long-term use. Placing the positive and negative terminals at opposite ends of the housing 21 also helps improve the heat dissipation performance of the battery cell 6. Since the electrode terminals 50 are typically the parts of the battery cell 6 that generate the most heat, placing them at opposite ends of the housing 21 allows for more effective heat distribution throughout the battery cell 6, thereby reducing the safety risks caused by localized overheating.

[0172] Two insulating sheets 30 are provided, each covering an end cap 22, providing additional insulation protection for the electrode terminals 50. Simultaneously, two bent portions 42 are connected to both ends of the main body 41 along the thickness direction Z and to the two insulating sheets 30 respectively. This design further enhances the overall insulation performance of the battery cell 6. The bent portions 42 not only provide an additional insulation barrier for the electrode terminals 50 but also increase the connection strength between the insulating sheets 30 and the end caps 22, improving structural stability.

[0173] By correspondingly arranging the two end caps 22, two insulating sheets 30, and two bent portions 42, an optimized layout of the battery cell 6 structure is achieved. This not only improves the electrical and insulation performance of the battery cell 6, but also facilitates the manufacturing and assembly process of the battery cell 6, reducing production costs and time.

[0174] In the above technical solution, the positive and negative terminals are respectively located at both ends of the housing 21, reducing the risk of short circuit between the positive and negative terminals. The two corresponding bends 42 provide good insulation for both the positive and negative terminals, improving the overall insulation performance of the battery cell 6.

[0175] As shown in Figures 4 to 6, in some embodiments of this application, the end cap 22 has a recess on the surface opposite to the electrode assembly, and at least a portion of the insulating sheet 30 is accommodated in the recess.

[0176] In the above structure, the recessed design can reduce the thickness of the insulating sheet 30 protruding from the end face of the end cap 22, thereby reducing the risk of interference between the insulating sheet 30 and other components on the end cap 22.

[0177] In some embodiments of this application, the surface of the insulating sheet 30 facing away from the electrode assembly is flush with the upper end face of the edge of the end cap 22. In this structure, the insulating sheet 30 is completely embedded in the recess, and its outer surface is flush with the upper end face of the end cap 22. This facilitates the setting of the bending portion 42, improves the flatness of the bending portion 42, and thus enhances the connection stability between the bending portion 42, the end cap 22, and the insulating sheet 30, thereby improving the insulation effect.

[0178] In some embodiments of this application, a gap 23 is provided between the insulating sheet 30 and the outer peripheral edge of the end cap 22, and the insulating film 40 covers the gap 23. The above technical solution reduces the risk of short circuit leakage at the gap 23 by covering the gap 23 between the insulating sheet 30 and the end cap 22 with the insulating film 40, thereby improving the insulation performance of the battery cell 6.

[0179] In some alternative embodiments, the battery cell 6 includes a housing 20, an electrode assembly, an insulating sheet 30, and an insulating film 40. The housing 20 includes a shell 21 and an end cap 22. The shell 21 has an opening, and the end cap 22 closes to the opening, forming a receiving cavity with the shell 21. The electrode assembly is disposed in the receiving cavity. The insulating sheet 30 is disposed on the side of the end cap 22 away from the receiving cavity and attached to the end cap 22. The insulating film 40 includes a main body 41 and a bent portion 42. The main body 41 covers the shell 21 from the outside, and the bent portion 42 is connected to one end of the main body 41 and bent relative to the main body 41. In the thickness direction Z of the end cap 22, at least a portion of the bent portion 42 is located on the side of the insulating sheet 30 opposite to the end cap 22. In the thickness direction Z, the bent portion 42 covers the outer periphery of the insulating sheet 30. The bending portion 42 includes a first portion 43 and a second portion 44 arranged opposite each other along a first direction X, and a third portion 45 and a fourth portion 46 arranged along a second direction Y. The first direction X, the second direction Y, and the thickness direction Z are perpendicular to each other. The first portion 43, the third portion 45, the second portion 44, and the fourth portion 46 are connected end to end in sequence. The first portion 43 and the third portion 45 partially overlap in the thickness direction Z. The main body portion 41 is wound around the outside of the housing 21. The main body portion 41 includes a winding start end and a winding end arranged opposite each other along the winding direction. A portion of the main body portion 41 is located between the winding end and the housing 21 to form an overlapping region 48. The housing 21 includes two first walls arranged opposite each other along the first direction X and two second walls arranged opposite each other along the second direction Y. The area of ​​the first wall is smaller than the area of ​​the second wall. The overlapping region 48 is located on the first wall. Two end caps 22 are provided on opposite sides of the housing 21 along a third direction. Two insulating sheets 30 and two bending portions 42 are correspondingly provided. The two bending portions 42 are respectively connected to the two ends of the main body 41 along the third direction and to the two insulating sheets 30. A gap 23 is provided between the insulating sheet 30 and the outer peripheral edge of the end cap 22, and an insulating film 40 covers the gap 23. The third direction intersects the plane containing the first direction X and the second direction Y. For example, the third direction is the same as the thickness direction Z of the end cap 22.

[0180] Embodiments of this application also provide a battery device 2, which includes the battery cell 6 in the above embodiments. Embodiments of this application also provide an electrical device, which includes the battery device 2 in the above embodiments, and the battery device 2 is used to provide electrical energy. In the above-mentioned battery device 2 and electrical device, by providing a housing 20 to accommodate the electrode assembly, damage to the electrode assembly caused by external moisture or impurities is reduced, providing a stable spatial environment for the operation of the electrode assembly and improving the operational stability of the battery cell 6. An opening is provided on the housing 21 to facilitate the assembly of the electrode assembly, and the end cap 22 closes the opening to improve the sealing performance of the housing 20. An insulating sheet 30 is used to insulate the end cap 22 from other components, and the main body 41 of the insulating film 40 surrounds the housing 21 and part of the end cap 22 to insulate the housing 21. Furthermore, the bent portion 42 of the insulating film 40 extends to the side of the insulating sheet 30 facing away from the end cap 22, and can cooperate with the insulating sheet 30 to insulate the end cap 22, extending the creepage distance between the end cap 22 and adjacent components, and improving the insulation performance of the battery cell 6.

[0181] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, comprising: a housing including a case and an end cap, the case being provided with an opening, the end cap covering the opening and forming a receiving cavity together with the case; an electrode assembly provided in the receiving cavity; an insulating sheet provided on a side of the end cap away from the receiving cavity and attached to the end cap; and an insulating film including a main body portion covering the case from an outer side and a bent portion connected to one end of the main body portion and bent with respect to the main body portion, at least a part of the bent portion being located on a side of the insulating sheet away from the end cap in a thickness direction of the end cap; wherein the bent portion covers an outer periphery of the insulating sheet in the thickness direction; wherein the bent portion includes a first portion and a second portion arranged opposite to each other in a first direction, a third portion and a fourth portion arranged opposite to each other in a second direction, the first direction, the second direction and the thickness direction being perpendicular to each other, and the first portion, the third portion, the second portion and the fourth portion being connected end to end in sequence; wherein the first portion and the third portion partially overlap in the thickness direction; wherein the main body portion is wound on an outer side of the case, the main body portion including a winding leading end and a winding trailing end arranged opposite to each other in a winding direction, and a part of the main body portion being located between the winding trailing end and the case to form an overlapping region; wherein the case includes two first walls arranged opposite to each other in the first direction and two second walls arranged opposite to each other in a second direction, an area of the first wall being smaller than an area of the second wall, and the overlapping region being provided on the first wall, the first direction, the second direction and the thickness direction being perpendicular to each other; wherein a width of a projection of the bent portion on the insulating sheet is D1, and a width of the end cap is D2, D1 and D2 satisfying 0.05≤D1 / D2≤0.2; wherein the insulating sheet includes: an insulating base layer provided on a side of the end cap away from the electrode assembly; and an adhesive layer provided between the end cap and the insulating base layer and bonding the insulating base layer to the end cap; wherein the battery cell further includes an electrode terminal provided on the end cap, at least a part of the end cap protruding from a surface of the end cap away from the electrode assembly; and the insulating sheet is provided with a through hole, and the electrode terminal is provided in the through hole; wherein a width of a projection of the electrode terminal on the end cap is D3, D3 and D2 satisfying 0.1≤D3 / D2<0.9; wherein the number of the end caps is two, the two end caps being provided on opposite sides of the case in a third direction, the insulating sheet being provided in a corresponding manner as two, the bent portion being provided in a corresponding manner as two, the two bent portions being connected to two ends of the main body portion in the third direction respectively and connected to the two insulating sheets respectively, the third direction intersecting a plane in which the first direction and the second direction lie; wherein a surface of the end cap away from the electrode assembly has a recess, and at least a part of the insulating sheet is accommodated in the recess; and wherein a surface of the insulating sheet away from the electrode assembly is flush with an upper end surface of an edge of the end cap. ​ ​ ​ ​ 2. The battery cell of claim 1, wherein, ​ 3. The battery cell of claim 1 or 2, wherein, ​ 4. The battery cell of claim 3, wherein, ​ 5. The battery cell of any one of claims 3-4, wherein, ​ 6. The battery cell of claim 5, wherein, ​ 7. The battery cell of any one of claims 1-6, wherein, ​ 8. The battery cell of any one of claims 1-7, wherein, ​ ​ ​ 9. The battery cell of any one of claims 1-8, wherein, ​ 10. The battery cell of claim 9, wherein, ​ 11. The battery cell of any one of claims 3-4, wherein, ​ 12. The battery cell of any one of claims 1-11, wherein, ​ 13. The battery cell of any one of claims 1-12, wherein, ​ 14. The battery cell of any one of claims 1-13, wherein, The insulating sheet is provided with a gap from the outer peripheral edge of the end cap, and the insulating film covers the gap.

15. A battery device comprising the battery cell according to any one of claims 1 to 14.

16. An electric appliance comprising the battery device according to claim 15, the battery device being used to supply electric power.

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