Battery cells, battery devices, electrical devices, and methods for preparing battery cells.

Abstract

This application provides a battery cell, a battery device, an electrical device, and a method for manufacturing a battery cell. The battery cell includes a casing, an electrode assembly, and an insulating film. The outer surface of the casing has a bottom surface, a first side surface, and a second side surface. The electrode assembly is housed within the casing, and the insulating film is disposed on the outer surface of the casing. The insulating film includes a first portion and a second portion. The first portion is attached to the first side surface and has a first flange extending to the bottom surface. The second portion is attached to the second side surface and has a second flange extending to the bottom surface. The second flange is located on the side of the first flange facing away from the bottom surface, and the first flange and the second flange partially overlap. The first flange includes a first surface facing away from the bottom surface, and the second flange includes a second surface facing away from the bottom surface. At least a portion of the first surface has a water contact angle greater than the water contact angle of the second surface, and at least a portion of the first surface has a water roll-off angle smaller than the water roll-off angle of the second surface.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, an electrical device, and a method for preparing a battery cell. Background Technology

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools, etc.

[0003] In the development of battery technology, improving the reliability of individual battery cells has become a research direction. Summary of the Invention

[0004] In view of the above problems, this application provides a battery cell, a battery device, an electrical device, and a method for preparing a battery cell, which can improve the reliability of the battery cell in use.

[0005] On one hand, this application provides a battery cell, which includes a casing, an electrode assembly, and an insulating film. The outer surface of the casing has a bottom surface, a first side surface, and a second side surface, which are arranged at an angle to each other. The electrode assembly is housed within the casing, and the insulating film is disposed on the outer surface of the casing.

[0006] The insulating film includes a first portion and a second portion. The first portion is adhered to a first side surface and has a first flange extending to the bottom surface. The second portion is adhered to a second side surface and has a second flange extending to the bottom surface. The second flange is located on the side of the first flange facing away from the bottom surface, and the first flange and the second flange partially overlap. The first flange includes a first surface facing away from the bottom surface, and the second flange includes a second surface facing away from the bottom surface. At least a portion of the first surface has a water contact angle greater than the water contact angle of the second surface, and at least a portion of the first surface has a water roll-off angle smaller than the water roll-off angle of the second surface.

[0007] In the above solution, by hydrophobically treating the first surface of the first flange, the water contact angle of at least a portion of the first surface is greater than that of the second surface, and the water roll-off angle of at least a portion of the first surface is smaller than that of the second surface. This gives the first surface stronger hydrophobic properties, preventing condensate from wetting the first surface and allowing it to form droplets that quickly roll off, thus preventing it from moving through the gaps to the outer casing. This reduces the probability of insulation failure in the casing and improves the reliability of the battery cell. Furthermore, in this embodiment, the hydrophobic treatment is applied only to a portion of the insulating film, rather than to the entire insulating film. This helps reduce the difficulty of the hydrophobication operation and improves the preparation efficiency.

[0008] In some embodiments, the area of ​​the second side is larger than the area of ​​the first side, and a portion of the structure in the second flange is attached to the first surface, while a portion of the structure is attached to the bottom surface.

[0009] In the above solution, the second flange not only overlaps with the first flange to complete the film application, but also has a portion of its structure that adheres to the bottom surface. This allows the second flange to provide protection for the bottom surface, achieving insulation protection for at least a portion of the bottom surface. Furthermore, because the second flange is bonded and fixed to the bottom surface, condensate is less likely to migrate from between the second flange and the bottom surface onto the outer casing. This reduces the probability of insulation failure in the casing and improves the reliability of the battery cells.

[0010] In some embodiments, the outer surface of the housing has a third side side arranged parallel to the second side side, and the bottom surface, the first side side, and the third side side are arranged at an angle, with the area of ​​the third side side being larger than the area of ​​the first side side. The insulating film also includes a third portion, which is attached to the third side side and has a third flange extending to the bottom surface. The third flange is located on the side of the second flange facing away from the bottom surface, and the first flange and the third flange partially overlap. The third flange includes a third surface facing away from the bottom surface, where at least a portion of the first surface has a water contact angle greater than that of the third surface, and at least a portion of the first surface has a water roll-off angle smaller than that of the third surface.

[0011] In the above solution, by hydrophobically treating the first surface on the first flange, the water contact angle of the first surface is not only greater than that of the second surface, but also greater than that of the third surface on the third flange. Furthermore, the water roll-off angle of at least a portion of the first surface is smaller than that of the third surface. As a result, the first surface has stronger hydrophobic properties, so that condensate will not wet the first surface and can form water droplets that roll off quickly, thus preventing it from moving to the outer casing through the gap. This reduces the probability of insulation failure of the outer casing and improves the reliability of the battery cell.

[0012] In some embodiments, the first surface includes a first overlapping region that overlaps with the second flange, the water contact angle of the first overlapping region being greater than the water contact angle of the second surface, and the water roll-off angle of the first overlapping region being less than the water roll-off angle of the second surface; and / or, the first surface includes a second overlapping region that overlaps with the third flange, the water contact angle of the second overlapping region being greater than the water contact angle of the third surface, and the water roll-off angle of the second overlapping region being less than the water roll-off angle of the second surface.

[0013] In the above scheme, the first overlapping area can be selectively hydrophobically treated, making the water contact angle of the first overlapping area larger than that of the second surface, and the water roll-off angle of the first overlapping area smaller than that of the second surface. This reduces the risk of condensate moving onto the casing through the gap between the first and second flanges, enhancing the reliability of the battery cell. Alternatively, the second overlapping area can also be selectively hydrophobically treated, making the water contact angle of the second overlapping area larger than that of the third surface, and the water roll-off angle of the second overlapping area smaller than that of the second surface. This also reduces the risk of condensate moving onto the casing through the gap between the first and third flanges, enhancing the reliability of the battery cell.

[0014] In some embodiments, the water contact angle of all regions in the first surface is greater than the water contact angle of the second surface, and the water roll-off angle of all regions in the first surface is less than the water roll-off angle of the second surface.

[0015] In the above solution, by treating all areas of the first surface with hydrophobicity, the water contact angle of all areas of the first surface is greater than that of the second surface, and the water roll-off angle of all areas of the first surface is less than that of the second surface. This design can reduce the risk of condensate partially wetting the first surface, reduce the risk of condensate passing through gaps and moving onto the casing, and improve the reliability of the battery cell.

[0016] In some embodiments, the first part includes a body portion that is fitted to the first side surface. The body portion includes a fourth surface of the first side surface. The water contact angle of at least a portion of the first surface is greater than the water contact angle of the fourth surface, and the water roll-off angle of all regions of the first surface is less than the water roll-off angle of the second surface.

[0017] In the above scheme, the first surface is located on the side of the first flange away from the bottom surface, and the fourth surface is located on the side of the body away from the first side surface. The water contact angle of at least a part of the first surface is greater than the water contact angle of the fourth surface, and the water roll-off angle of all parts of the first surface is less than the water roll-off angle of the second surface. That is, only the first surface is hydrophobically treated, while the fourth surface is not hydrophobically treated. This design helps to reduce the difficulty of hydrophobication operation and improve the preparation efficiency.

[0018] In some embodiments, the water contact angle in at least a portion of the first surface is α, where α satisfies: α ≥ 150°.

[0019] In the above solution, by hydrophobically treating the first surface, the water contact angle α in at least a portion of the first surface can be no less than 150°, so that condensate will not wet the first surface, thus improving the reliability of the battery cell.

[0020] In some embodiments, the water roll-off angle in at least a portion of the first surface is b, where b satisfies: b≤10°.

[0021] In the above solution, by hydrophobically treating the first surface, the water roll-off angle b in at least a portion of the first surface is no greater than 10°, thereby helping the condensate on the first surface to roll off quickly, reducing the risk of condensate accumulating on the first surface and wetting the outer casing, and improving the reliability of the battery cell.

[0022] In some embodiments, the second flange includes a fifth surface facing the bottom surface, the water contact angle of the fifth surface being greater than that of the second surface, and the water roll-off angle of the fifth surface being less than that of the second surface.

[0023] In the above solution, in addition to hydrophobizing the first surface, the fifth surface is also hydrophobically treated, making the water contact angle of the fifth surface larger than that of the second surface, and the water roll-off angle of the fifth surface smaller than that of the second surface. This allows condensate adhering to the first surface to roll off quickly, making it difficult for it to move to the outer casing through gaps. Similarly, condensate adhering to the fifth surface can also roll off quickly, making it difficult for it to move to the outer casing through gaps, thereby further improving the reliability of the battery cell.

[0024] In some embodiments, the second flange includes a first portion and a second portion that are bent and stacked, the second portion being located on the side of the first portion away from the bottom surface, and the first portion including a fifth surface and bent and connected to the first flange.

[0025] In the above scheme, the surface of the first section facing the second section and the surface of the second section facing the first section are bonded and fixed to each other, while the fifth surface of the first section facing the bottom is not bonded and fixed to the first surface of the first flange. Based on this, by applying a hydrophobic treatment to the first and fifth surfaces, condensate on the first and fifth surfaces can quickly roll off, thereby reducing the risk of condensate seeping into the casing from between the first section and the first flange, and improving the reliability of the battery cell.

[0026] Secondly, embodiments of this application provide a battery device, which includes a single battery cell in any of the foregoing embodiments.

[0027] In some embodiments, the battery device further includes a heat dissipation assembly surrounding the battery cell, the heat dissipation assembly including a first heat dissipation portion covering the second side, the first heat dissipation portion being recessed on the side facing the second surface to form an air supply channel.

[0028] In the above-mentioned scheme, the heat dissipation component can meet the air cooling heat dissipation of the battery cell. However, air cooling heat dissipation is prone to causing condensation to form on the battery cell. In view of this, the embodiment of this application performs hydrophobic treatment on the first surface of the first flange, so that the water contact angle of at least a part of the first surface is greater than the water contact angle of the second surface. As a result, the first surface can have stronger hydrophobic properties. In this way, condensation will not wet the first surface and can form water droplets and roll off quickly, so that condensation cannot move to the outer shell through the gap, thereby reducing the probability of insulation failure of the outer shell and improving the reliability of the battery cell.

[0029] Thirdly, embodiments of this application provide an electrical device, which includes the battery device in any of the foregoing embodiments.

[0030] Fourthly, embodiments of this application provide a method for preparing a single battery cell, the method comprising:

[0031] A housing is provided, the outer surface of which has a bottom surface, a first side surface, and a second side surface, the bottom surface, the first side surface, and the second side surface being arranged at an angle to each other;

[0032] An insulating film is placed around the outer periphery of the housing. The insulating film includes a first part attached to a first side and a second part attached to a second side. The first part extends beyond the first side and faces the bottom, and the second part extends beyond the second side and faces the bottom.

[0033] The portion of the first part that extends beyond the first side is bent to form a first flange attached to the bottom surface. The first flange includes a first surface that faces away from the bottom surface.

[0034] The first surface is hydrophobicated;

[0035] The portion of the second part that extends beyond the first side is bent to form a second flange that is attached to the side of the first flange facing away from the bottom surface.

[0036] In the above scheme, the first part is first bent to form the first flange, and then the first surface of the first flange is hydrophobically treated. This eliminates the need to pre-determine the areas in the insulating film that require hydrophobic treatment, allowing for precise hydrophobic treatment of the first surface. Furthermore, during the hydrophobic treatment process, the outer shell can provide support for the first flange, reducing the risk of deformation and thus simplifying the hydrophobic treatment operation and improving manufacturing efficiency.

[0037] In some embodiments, the step of hydrophobizing the first surface includes:

[0038] The first surface is subjected to ion bombardment treatment to form an uneven micro-nano composite structure on the first surface;

[0039] A hydrophobic agent is sprayed onto the first surface.

[0040] In the above scheme, during the hydrophobic treatment process, high-energy ion bombardment is first used to physically etch the first surface, and then a hydrophobic agent is sprayed on the first surface. This method helps to form a robust superhydrophobic surface on the first surface, thereby improving hydrophobic performance, reducing the risk of condensate contacting the casing, and improving the reliability of the battery cell.

[0041] 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, specific embodiments of this application are given below. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application;

[0044] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0045] Figure 3 This is a schematic diagram of the structure of a battery module in a battery device provided in some embodiments of this application;

[0046] Figure 4 This is a schematic diagram of the structure of a single battery cell provided in some embodiments of this application;

[0047] Figure 5 yes Figure 4 A magnified structural diagram of region Q in the middle region;

[0048] Figure 6 This is a schematic diagram of the exploded structure of some components in an electric field unit provided in some embodiments of this application;

[0049] Figure 7 This is a schematic diagram of the preparation process of an electric field monomer provided in some embodiments of this application;

[0050] Figure 8 This is a schematic diagram of the preparation process of an electric field monomer provided in some embodiments of this application;

[0051] Figure 9 This is a partial structural schematic diagram of an electric field device provided in some embodiments of this application;

[0052] Figure 10 This is a flowchart illustrating a method for preparing an electric field monomer according to some embodiments of this application;

[0053] Figure 11 This is a flowchart of a method for preparing an electric field monomer provided in some embodiments of this application.

[0054] Explanation of reference numerals in the attached figures:

[0055] 1000, Vehicle; 100, Battery unit; 200, Controller; 300, Motor; 400, Housing; 401, First housing section; 402, Second housing section; 403, Receiving section; 500, Battery cell; 600, Battery module;

[0056] 10. Outer shell; 11. Bottom surface; 12. First side surface; 13. Second side surface; 14. Third side surface;

[0057] 20. Insulating film; 21. First part; 211. First flange; 212. Body part; 22. Second part; 221. Second flange; 221a. First section; 221b. Second section; 23. Third part; 231. Third flange;

[0058] 30. Electrode assembly;

[0059] 40. Heat dissipation assembly; 41. First heat dissipation section; 42. Second heat dissipation section; 43. Air supply channel;

[0060] M1, First surface; M2, Second surface; M3, Third surface; M4, Fourth surface; M5, Fifth surface;

[0061] X, first direction; Y, second direction; Z, third direction. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0067] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0068] Unless otherwise specified, all steps of this application may be performed sequentially or randomly, preferably sequentially. For example, the method includes steps (a) and (b), indicating that the method may include steps (a) and (b) performed sequentially, or it may include steps (b) and (a) performed sequentially. For example, the mention that the method may also include step (c) indicates that step (c) may be added to the method in any order; for example, the method may include steps (a), (b), and (c), or it may include steps (a), (c), and (b), or it may include steps (c), (a), and (b), etc.

[0069] 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.

[0070] 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).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.).

[0079] 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 positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate 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 manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co At least one of the following: 0.25Mn0.25O2 (also abbreviated as NCM211), LiNi0.6Co0.2Mn0.2O2 (also abbreviated as NCM622), LiNi0.8Co0.1Mn0.1O2 (also abbreviated as NCM811), lithium nickel cobalt aluminum oxide (such as LiNi0.8Co0.15Al0.05O2), and their modified compounds. Modified compounds refer to substances obtained by doping or coating, etc., based on the above-mentioned materials.

[0080] In some embodiments, the positive 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 positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, a positive electrode active material is filled and / or deposited within the foamed metal.

[0081] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0082] 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.).

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0088] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0089] 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 may include electrolyte salts and solvents.

[0090] 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.

[0091] 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.

[0092] 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.

[0093] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0094] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0095] In some implementations, the electrode assembly is a stacked structure.

[0096] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0097] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0098] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0099] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0100] As an example, the separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0101] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0102] 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.

[0103] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing), etc.

[0104] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, it serves to protect the electrode assembly, and a sealing bag is included between the housing and the electrode assembly to encapsulate the electrode assembly and electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the housing is a sealed structure, it is used to encapsulate the electrode assembly 30 and other components such as the electrolyte.

[0105] As an example, a battery cell can be a prismatic battery cell or a battery cell of other shapes, including prismatic battery cells.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0110] 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.

[0111] 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.

[0112] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0113] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0118] In battery cells, the insulating film is typically coated using a U-shaped or spiral-shaped coating method, which is simple, convenient, and quick. However, these coating methods often result in folded, multi-layered insulating films in certain areas of the casing. Furthermore, the insulating film usually has adhesive on only one side. Within these folded, multi-layered insulating films, some sections have folds formed by the film itself, leaving these folds without adhesive on either side along their thickness. Therefore, gaps are created between the folds and adjacent insulating films in these folded, multi-layered insulating films.

[0119] In some applications, battery cells are in direct contact with air. Since the insulating film is usually made of a hydrophilic substrate, condensation will form on the surface of the insulating film at low temperatures. As mentioned above, gaps will form between the folded portion and the adjacent insulating film. These gaps can easily cause condensation to flow onto the outer casing, leading to insulation failure and affecting the reliability of the battery cells.

[0120] In view of this, embodiments of this application provide a battery cell, a battery device, an electrical device, and a method for preparing a battery cell. By hydrophobically treating the first surface on the first flange, the water contact angle of at least a portion of the first surface is greater than that of the second surface. As a result, the first surface has stronger hydrophobic properties, making it relatively difficult for condensate on the first surface to diffuse and spread. This reduces the risk of condensate flowing through the gap on the first surface and moving onto the outer casing, thereby reducing the probability of insulation failure of the outer casing and improving the reliability of the battery cell.

[0121] The technical solutions described in this application are applicable to battery cells, battery devices, and electrical devices using battery devices. Electrical devices can take many forms, 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.

[0122] The battery devices described in this application are not limited to the electrical devices described above, but for the sake of brevity, the following embodiments are all illustrated using electric vehicles as an example.

[0123] Please see Figure 1 , Figure 1 This is a simplified schematic diagram of a vehicle 1000 provided in an embodiment of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 can be installed inside the vehicle 1000; specifically, for example, the battery device 100 can be installed at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 100 may also include a controller 200 and a motor 300. The controller 200, for example, is used to control the battery to supply power to the motor 300. The battery device 100 can be used for starting, navigation, etc., of the vehicle 1000. Of course, the battery device 100 can also be used to drive the vehicle 1000, replacing or partially replacing gasoline or natural gas to provide propulsion for the vehicle 1000.

[0124] Please refer to Figure 2 , Figure 2This is an exploded view of a battery device provided in some embodiments of this application. The battery device 100 includes a housing 400 and individual battery cells (not shown), which are housed within the housing 400. The housing 400 is used to house the battery cells, and the housing 400 can have various structures. In some embodiments, the housing 400 may include a first housing portion 401 and a second housing portion 402, which overlap each other, and the first housing portion 401 and the second housing portion 402 together define a receiving portion 403 for housing the battery cells. The second box portion 402 can be a hollow structure with one end open, and the first box portion 401 is a plate-like structure. The first box portion 401 covers the open side of the second box portion 402 to form a box with a receiving portion 403. Alternatively, both the first box portion 401 and the second box portion 402 can be hollow structures with one side open, and the open side of the first box portion 401 covers the open side of the second box portion 402 to form a box 400 with a receiving portion. Of course, the first box portion 401 and the second box portion 402 can be various shapes, such as cylinders, cuboids, etc.

[0125] In the battery device 100, 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 mixed configuration. A mixed configuration means that multiple battery cells are connected in both series and parallel configurations. Multiple battery cells can be directly connected in series, in parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells is housed within the housing 400. Alternatively, multiple battery cells can first be connected in series, in parallel, or in a mixed configuration to form a battery module 600, and then the multiple battery modules 600 can be connected in series, in parallel, or in a mixed configuration to form a whole, which is then housed within the housing 400.

[0126] Figure 3 for Figure 2 The diagram shows an exploded view of the battery module 600. In some embodiments, such as... Figure 3 As shown, there are multiple battery cells 500. These multiple battery cells 500 are first connected in series, parallel, or in a mixed manner to form a battery module 600. The multiple battery modules 600 are then connected in series, parallel, or in a mixed manner to form a whole, which is housed in the casing.

[0127] The structure of the battery cell will then be described with reference to the accompanying drawings. Please refer to [the attached diagram]. Figures 4 to 8 The battery cell includes a housing 10, an electrode assembly 30, and an insulating film 20. The outer surface of the housing 10 has a bottom surface 11, a first side surface 12, and a second side surface 13, which are arranged at an angle to each other. The electrode assembly 30 is housed within the housing 10, and the insulating film 20 is disposed on the outer surface of the housing 10.

[0128] The insulating film 20 includes a first portion 21 and a second portion 22. The first portion 21 is attached to a first side surface 12 and has a first flange 211 extending to a bottom surface 11. The second portion 22 is attached to a second side surface and has a second flange 221 extending to a bottom surface 11. The second flange 221 is located on the side of the first flange 211 facing away from the bottom surface 11, and the first flange 211 and the second flange 221 partially overlap. The first flange 211 includes a first surface M1 facing away from the bottom surface 11, and the second flange 221 includes a second surface M2 facing away from the bottom surface 11. At least a portion of the first surface M1 has a water contact angle greater than the water contact angle of the second surface M2, and at least a portion of the first surface M1 has a water roll-off angle smaller than the water roll-off angle of the second surface M2.

[0129] The outer casing 10 is a component used to form the internal environment of a single battery cell. This internal environment can accommodate the electrode assembly 30, the electrolyte, and other components. The electrode assembly 30 is the component in the single battery cell where electrochemical reactions occur. The electrode assembly 30 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 30, while the portions without active material each constitute a tab. The positive and negative tabs can be located together at one end of the main body or separately at both ends. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs connect to the electrode terminals to form a current loop.

[0130] An insulating film 20 is disposed on the outer surface of the housing 10 to reduce short circuits in the internal circuitry of the battery cell caused by external physical impacts, chemical corrosion, or other reasons. Both the housing 10 and the insulating film 20 can be made of various materials. Specifically, the housing 10 can be made of a metallic material, such as copper, aluminum, or stainless steel. The insulating film 20 comprises an insulating material, such as polyethylene, polyimide, polyvinylidene fluoride, or polytetrafluoroethylene.

[0131] The bottom surface 11, the first side surface 12, and the second side surface 13 all form the outer surface of the outer shell 10. The bottom surface 11, the first side surface 12, and the second side surface 13 are arranged at an angle, that is, the bottom surface 11, the first side surface 12, and the second side surface 13 are located at different positions on the outer shell 10 along different directions. Among them, the first side surface 12 and the second side surface 13 are both circumferential surfaces of the outer shell 10. Optionally, the first side surface 12 is a surface of the outer shell 10 in the first direction X, the second side surface 13 is a surface of the outer shell 10 in the second direction Y, and the bottom surface 11 is a surface of the outer shell 10 in the third direction Z. The first direction X, the second direction Y, and the third direction Z intersect each other, and further, the three directions are perpendicular to each other.

[0132] The insulating film 20 includes a first portion 21 and a second portion 22, which can be integrally connected. The first portion 21 provides protection for the first side 12, and the second portion 22 provides protection for the second side 13. The first portion 21 has a first flange 211 extending to the bottom surface 11, and the second portion 22 has a second flange 221 extending to the bottom surface 11. Thus, the first flange 211 provides protection for the junction between the bottom surface 11 and the first side 12, and the second flange 221 provides protection for the junction between the bottom surface 11 and the second side 13.

[0133] The first flange 211 and the second flange 221 partially overlap. In a projection plane perpendicular to the third direction Z, the orthographic projections of the first flange 211 and the second flange 221 overlap. The second flange 221 is located on the side of the first flange 211 facing away from the bottom surface 11. That is, during the process of attaching the insulating film 20 to the outer shell 10, a portion of the structure in the first part 21 is first bent to form the first flange 211 attached to the bottom surface 11, and then a portion of the structure in the second part 22 is bent to form the second flange 221. The attachment mentioned here is not limited to direct contact between different structures. For example, adhesive bonding between different structures and minute gaps between different structures can also be considered attachment, as long as there are no other structures besides the adhesive between the different structures.

[0134] It should be noted that the size relationship between the first part 21 and the second part 22 depends on the area relationship between the first side 12 and the second side 13. The area of ​​the first side 12 can be larger than the area of ​​the second side 13, or the area of ​​the first side 12 can be smaller than the area of ​​the second side 13. Therefore, the size of the first part 21 can be larger than the size of the second part 22, or it can be smaller than the size of the second side 221. Based on this, the size of the first flange 211 can be larger than the size of the second flange 221, or it can be smaller than the size of the second flange 221. As for the second flange 221, under different size conditions, the second flange 221 can be completely attached to the first flange 211 and other flanges, or the second flange 221 can be partially attached to the first flange 211 and partially attached to the bottom surface 11.

[0135] Furthermore, the housing 10 can have various shapes, as long as the outer surface of the housing 10 includes a bottom surface 11, a first side surface 12, and a second side surface 13 that intersect, and the insulating film 20 has a first flange 211 and a second flange 221 that extend from different sides to the bottom surface 11 and partially overlap each other. Optionally, the housing 10 can have a square structure.

[0136] In the process of attaching the insulating film 20 to the outer casing 10, the film application needs to be completed on the bottom surface 11 at the intersection of the first side surface 12 and the second side surface 13 using the first flange 211 and the second flange 221. During the film application process, the first flange 211 is bonded to the bottom surface 11, while the second flange 221 folds itself in the area overlapping with the first flange 211 to form a folded portion. There is no adhesive material on the side of the folded portion facing the first flange 211 and on the side of the first flange 211 facing the folded portion. Therefore, the first flange 211 and the second flange 221 are not bonded together, resulting in a gap. The existence of the gap makes it easy for condensate to move onto the outer casing 10, which can lead to insulation failure of the outer casing 10 and affect the reliability of the battery cells.

[0137] In view of this, the insulating film 20 is adjusted in this embodiment. Specifically, the first surface M1 is the surface of the first flange 211 facing the second flange 221, and the second surface M2 is the surface of the second flange 221 facing away from the bottom surface 11. When there is condensation on the surface of the insulating film 20, the condensation needs to flow on the first surface M1 to pass through the gap and move to the outer shell 10. Based on this, the first surface M1 is hydrophobically treated so that the water contact angle of at least a portion of the first surface M1 is greater than the water contact angle of the second surface M2, and the water roll-off angle of at least a portion of the first surface M1 is less than the water roll-off angle of the second surface M2. The water contact angle mentioned here, also known as the water wetting angle, refers to the angle between the solid-liquid interface, the liquid interior, and the gas-liquid interface at the solid-liquid-gas three-phase interface. It reflects the degree of wetting of the solid by the liquid and is a quantitative measure of surface wettability. A drop of condensation on clean glass will spread out and wet the surface, while a drop of condensation on a waxy surface will remain as a bead and not wet. Wetting and non-wetting are not polar opposites but a quantifiable quantity. The parameter that quantifies the degree of wetting is the water contact angle.

[0138] Typically, the water contact angle can be measured using a goniometer, such as a static contact angle meter, by placing a water droplet on the first surface M1 and the second surface M2 and measuring the angle separately. Generally, the larger the water contact angle, the greater the contraction of the liquid on the solid surface, and the stronger the hydrophobicity of the surface. Conversely, the smaller the water contact angle, the greater the spread of the liquid on the solid surface, and the stronger the hydrophilicity of the surface.

[0139] The water roll-off angle refers to the critical angle at which a droplet begins to roll on an inclined solid surface. It is used to evaluate the wettability and hydrophobicity of a surface. It reflects contact hysteresis; a smaller water roll-off angle indicates stronger surface hydrophobicity and better droplet rolling performance on that surface.

[0140] In summary, in this embodiment, by hydrophobically treating the first surface M1 on the first flange 211, the water contact angle of at least a portion of the first surface M1 is greater than that of the second surface M2, and the water roll-off angle of at least a portion of the first surface M1 is smaller than that of the second surface M2. This results in the first surface M1 having stronger hydrophobic properties, preventing condensate from wetting the first surface M1 and allowing it to form droplets that quickly roll off. Consequently, the condensate cannot move through the gaps to the outer casing 10, thus reducing the probability of insulation failure in the outer casing 10 and improving the reliability of the battery cell. Furthermore, this embodiment only hydrophobically treats a portion of the insulating film 20, rather than the entire insulating film 20, which helps reduce the difficulty of the hydrophobication operation and improves the preparation efficiency.

[0141] It should be noted that the battery cell can be prepared in various ways. For example, it can be hydrophobically treated first, and then the insulating film 20 can be attached to the outer shell 10. Alternatively, the insulating film 20 can be partially hydrophobically treated during the attachment process to the outer shell 10. Furthermore, the hydrophobic treatment can take several forms. Optionally, the first surface M1 can be cleaned with alcohol to ensure it is free of dust and dirt. Then, the first surface M1 can be bombarded with high-energy ions (such as oxygen, argon, and nitrogen) to physically etch it, forming a micron or nano-scale uneven structure, i.e., a micro-nano composite structure. This micro-nano composite structure provides a better adhesion surface for chemical modification, resulting in a more robust superhydrophobic surface. Afterward, a hydrophobic agent is sprayed onto the first surface M1 for chemical modification. Finally, the battery cell is placed in a dry environment at 40°C for 2 hours to complete the hydrophobic treatment.

[0142] Furthermore, depending on the actual needs, all areas of the first surface M1 can be configured to have a large water contact angle, meaning that all areas of the first surface M1 have strong hydrophobic properties. Alternatively, some areas of the first surface M1 can have a small water contact angle, meaning that some areas of the first surface M1 have weak hydrophobic properties.

[0143] like Figures 4 to 6 As shown, in some embodiments, the area of ​​the second side 13 is larger than the area of ​​the first side 12, and part of the structure in the second flange 221 is attached to the first surface M1, and part of the structure is attached to the bottom surface 11.

[0144] The area of ​​the second side 13 is larger than the area of ​​the first side 12, meaning the first side 12 is a narrow surface, while the second side 13 is a large surface. Here, a large surface refers to the surface with a larger area in the circumferential direction of the outer shell 10, while a narrow surface refers to the surface with a smaller area in the circumferential direction of the outer shell 10. Optionally, the dimension of the first side 12 in the second direction Y is larger than the dimension of the second side 13 in the first direction X.

[0145] Part of the structure in the second flange 221 is attached to the first surface M1, and part of the structure is attached to the bottom surface 11. Specifically, the second flange 221 includes an integrally connected folded portion and a non-folded portion in the second direction Y. The folded portion is formed by the self-folding of a portion of the structure in the second flange 221, while the non-folded portion is the portion of the structure in the second flange 221 that does not fold itself. The folded portion overlaps with the first flange 211, that is, the first flange 211 is spaced apart between the folded portion and the bottom surface 11, and at least a portion of the non-folded portion is in direct contact with the bottom surface 11. Furthermore, at least a portion of the non-folded portion can be bonded and fixed to the bottom surface 11.

[0146] In this embodiment, the second flange 221 not only partially overlaps with the first flange 211 to complete the film application, but also a portion of the structure in the second flange 221 can adhere to the bottom surface 11. This allows the second flange 221 to provide protection for the bottom surface 11, thereby achieving insulation protection for at least a portion of the bottom surface 11. Furthermore, since the second flange 221 is bonded and fixed to the bottom surface 11, condensate is unlikely to migrate from between the second flange 221 and the bottom surface 11 onto the outer casing 10. This reduces the probability of insulation failure in the outer casing 10 and improves the reliability of the battery cell.

[0147] In some embodiments, the outer surface of the housing 10 has a third side surface 14 arranged side-by-side with the second side surface 13. The bottom surface 11, the first side surface 12, and the third side surface 14 are arranged at an angle, and the area of ​​the third side surface 14 is larger than the area of ​​the first side surface 12. The insulating film 20 also includes a third portion 23, which is attached to the third side surface 14 and has a third flange 231 extending to the bottom surface 11. The third flange 231 is located on the side of the second flange 221 facing away from the bottom surface 11, and the first flange 211 and the third flange 231 partially overlap. The third flange 231 includes a third surface M3 facing away from the bottom surface 11. The water contact angle of at least a portion of the first surface M1 is greater than the water contact angle of the third surface M3, and the water roll-off angle of at least a portion of the first surface M1 is less than the water roll-off angle of the third surface M3.

[0148] The third side 14 and the second side 13 are arranged side by side in the second direction Y. Both the third side 14 and the second side 13 are large surfaces, meaning that the area of ​​both is larger than the area of ​​the first side 12. Optionally, the second side 13 and the third side 14 have the same area.

[0149] The insulating film 20 includes a third portion 23, which provides protection for the third side surface 14. The third portion 23 has a third flange 231 extending to the bottom surface 11, such that the third flange 231 provides protection at the junction between the bottom surface 11 and the third side surface 14. The first portion 21 is integrally connected to the second portion 22 and the third portion 23 at both ends in the second direction Y.

[0150] The third flange 231 is located on the side of the second flange 221 that is away from the bottom surface 11. That is, during the final application of the film, a portion of the structure in the first part 21 is first bent to form the first flange 211 that is attached to the bottom surface 11, then a portion of the structure in the second part 22 is bent to form the second flange 221, and then a portion of the structure in the third part 23 is bent to form the third flange 231.

[0151] The first flange 211 and the third flange 231 partially overlap. Similar to the second flange 221, the third flange 231 also includes an integrally connected folded portion and a non-folded portion in the second direction Y. The folded portion in the third flange 231 partially overlaps with the first flange 211. Furthermore, the non-folded portion in the third flange 231 partially overlaps with the non-folded portion in the second flange 221, and the two are bonded and fixedly disposed. In this way, the non-folded portions in the third flange 231 and the non-folded portions in the second flange 221 can jointly provide protection for most of the area of ​​the bottom surface 11, and the bonded connection between the two can reduce the movement of condensate from between the second flange 221 and the third flange 231 onto the outer casing 10, thereby reducing the probability of insulation failure of the outer casing 10 and improving the reliability of the battery cell 500.

[0152] Furthermore, in this embodiment, by hydrophobically treating the first surface M1 on the first flange 211, the water contact angle of the first surface M1 is not only greater than that of the second surface M2, but also greater than that of the third surface M3 on the third flange 231. Moreover, the water roll-off angle of at least a portion of the first surface M1 is smaller than that of the third surface M3. As a result, the first surface M1 has stronger hydrophobic properties, so that condensate will not wet the first surface M1 and can form water droplets that roll off quickly, thus preventing it from moving to the outer casing 10 through the gap. This reduces the probability of insulation failure of the outer casing 10 and improves the reliability of the battery cell 500.

[0153] In some alternative embodiments, the water contact angle of the second surface M2 may be equal to the water contact angle of the third surface M3, that is, the insulating film 20 only performs hydrophobic treatment on the first surface M1 of the first flange 211, and does not perform hydrophobic treatment on the second surface M2 of the second flange 221 and the third surface M3 of the third flange 231.

[0154] In some embodiments, the first surface M1 includes a first overlapping region that overlaps with the second flange 221, the water contact angle of the first overlapping region being greater than the water contact angle of the second surface M2, and the water roll-off angle of the first overlapping region being less than the water roll-off angle of the second surface M2; and / or, the first surface M1 includes a second overlapping region that overlaps with the third flange 231, the water contact angle of the second overlapping region being greater than the water contact angle of the third surface M3, and the water roll-off angle of the second overlapping region being less than the water roll-off angle of the third surface M3.

[0155] Combination Figure 5 and Figure 8It can be seen that the area where the first flange 211 overlaps with the second flange 221 is the first overlapping area, and the area where the first flange 211 overlaps with the third flange 231 is the second overlapping area. Both the first and second overlapping areas are triangular. The first and second areas partially overlap, and the second area is partially located outside the first area. Furthermore, in a local area outside the first area and within the second area, the first flange 211 and the third flange 231 can be directly attached. However, since they are not bonded together, gaps are easily created. This allows condensate to move through the gaps between the first flange 211 and the third flange 231 onto the outer casing 10, potentially causing insulation failure in the outer casing 10.

[0156] Therefore, embodiments of this application can selectively hydrophobize the first overlapping region, making the water contact angle of the first overlapping region greater than the water contact angle of the second surface M2, and the water roll-off angle of the first overlapping region smaller than the water roll-off angle of the second surface M2. This reduces the risk of condensate moving onto the outer casing 10 through the gap between the first flange 211 and the second flange 221, thereby enhancing the reliability of the battery cell 500. Alternatively, the second overlapping region can also be selectively hydrophobically treated, making the water contact angle of the second overlapping region greater than the water contact angle of the third surface M3, and the water roll-off angle of the second overlapping region smaller than the water roll-off angle of the third surface M3. This also reduces the risk of condensate moving onto the outer casing 10 through the gap between the first flange 211 and the third flange 231, thereby enhancing the reliability of the battery cell 500.

[0157] In some alternative embodiments, the water contact angle of the first overlapping region is greater than the water contact angle of the second surface M2, and the water contact angle of the second overlapping region is greater than the water contact angle of the third surface M3.

[0158] In some embodiments, the water contact angle of all regions in the first surface M1 is greater than the water contact angle of the second surface M2, and the water roll-off angle of all regions in the first surface M1 is less than the water roll-off angle of the second surface M2.

[0159] In this embodiment, by hydrophobically treating all areas of the first surface M1, the water contact angle of all areas of the first surface M1 is greater than that of the second surface M2, and the water roll-off angle of all areas of the first surface M1 is less than that of the second surface M2. This design can reduce the risk of condensate partially wetting the first surface M1, reduce the risk of condensate passing through the gap and moving onto the outer casing 10, and improve the reliability of the battery cell 500.

[0160] In some embodiments, the first part 21 includes a body part 212 that is fitted to the first side surface 12. The body part 212 includes a fourth surface M4 of the first side surface 12. The water contact angle of at least a portion of the first surface M1 is greater than the water contact angle of the fourth surface M4, and the water roll-off angle of all regions of the first surface M1 is less than the water roll-off angle of the second surface M2.

[0161] The main body 212 and the first flange 211 are integral structures and are bent and connected together. The main body 212 is disposed on the first side 12, and the first flange 211 is bent from the main body 212 and extends to the bottom surface 11. The main body 212 can protect the first side 12, while the first flange 211 can protect the intersection of the bottom surface 11 and the first side 12.

[0162] In this embodiment, the first surface M1 is located on the side of the first flange 211 away from the bottom surface 11, and the fourth surface M4 is located on the side of the body 212 away from the first side surface 12. The water contact angle of at least a portion of the first surface M1 is greater than the water contact angle of the fourth surface M4, and the water roll-off angle of all areas of the first surface M1 is less than the water roll-off angle of the second surface M2. That is, only the first surface M1 is hydrophobically treated, while the fourth surface M4 is not hydrophobically treated. This design helps to reduce the difficulty of hydrophobication operation and improve the preparation efficiency.

[0163] In some embodiments, the water contact angle in at least a portion of the first surface M1 is α, where α satisfies: α ≥ 150°. Exemplarily, α is one of 150°, 160°, 170°, 180°, and 200°.

[0164] In this embodiment, by hydrophobically treating the first surface M1, the water contact angle α in at least a portion of the first surface M1 is not less than 150°, so that condensate will not wet the first surface M1, thereby improving the reliability of the battery cell 500.

[0165] In some embodiments, the water roll-off angle in at least a portion of the first surface M1 is b, where b ≤ 10°. Exemplarily, b is one of 2°, 4°, 5°, 8°, and 10°.

[0166] This application embodiment treats the first surface M1 with hydrophobicity so that the water roll-off angle b in at least a portion of the first surface M1 is no greater than 10°. This helps the condensate on the first surface M1 to roll off quickly, reducing the risk of condensate accumulating on the first surface M1 and wetting the outer casing 10, thereby improving the reliability of the battery cell 500.

[0167] In some embodiments, such as Figure 4 , Figure 5 and Figure 8 As shown, the second flange 221 includes a fifth surface M5 facing the bottom surface 11. The water contact angle of the fifth surface M5 is greater than the water contact angle of the second surface M2, and the water roll-off angle of the fifth surface M5 is less than the water roll-off angle of the second surface M2.

[0168] The fifth surface M5 is disposed opposite to the first surface M1, and the two are not bonded together. Therefore, gaps are easily generated between the insulating film 20 and the first surface M1 and the fifth surface M5. Based on this, there is a risk that condensate on the first surface M1 and condensate on the fifth surface M5 may move to the outer shell 10 through the gaps.

[0169] Therefore, in addition to hydrophobicating the first surface M1, this embodiment of the application also hydrophobically treats the fifth surface M5, making the water contact angle of the fifth surface M5 larger than that of the second surface M2, and the water roll-off angle of the fifth surface M5 smaller than that of the second surface M2. This allows condensate adhering to the first surface M1 to roll off quickly, making it difficult for it to move to the outer casing 10 through the gap. Similarly, condensate adhering to the fifth surface M5 can also roll off quickly, making it difficult for it to move to the outer casing 10 through the gap, thereby further improving the reliability of the battery cell 500.

[0170] In some embodiments, the second flange 221 includes a first portion 221a and a second portion 221b that are bent and stacked. The second portion 221b is located on the side of the first portion 221a away from the bottom surface 11. The first portion 221a includes a fifth surface M5 and is bent and connected to the first flange 211.

[0171] The first portion 221a and the second portion 221b are bent and connected, and are stacked together, forming the folded portion of the second flange 221. Optionally, in a projection plane perpendicular to the third direction Z, the orthographic projection of the first portion 221a coincides with the orthographic projection of the second portion 221b. Further, both the orthographic projections of the first portion 221a and the second portion 221b are triangular.

[0172] The second portion 221b is located on the side of the first portion 221a that faces away from the bottom surface 11. That is, the first portion 221a is fitted with the first flange 211, while the second portion 221b is fitted with the third flange 231. During the process of bending a part of the structure in the first portion 21 to form the first flange 211 fitted to the bottom surface 11, since the first portion 21 and the second portion 22 are integrally connected, when the first portion 21 is bent, a part of the structure in the second portion 22 will also be bent and deformed, thereby forming the bent and stacked first portion 221a and second portion 221b.

[0173] In this embodiment, the surface of the first portion 221a facing the second portion 221b is bonded and fixed to the surface of the second portion 221b facing the first portion 221a, while the fifth surface M5 of the first portion 221a facing the bottom surface 11 is not bonded and fixed to the first surface M1 of the first flange 211. Based on this, by hydrophobically treating the first surface M1 and the fifth surface M5, condensate on the first surface M1 and the fifth surface M5 can quickly roll off, thereby reducing the risk of condensate seeping into the outer casing 10 from between the first portion 221a and the first flange 211, and improving the reliability of the battery cell 500.

[0174] In some embodiments, the water contact angle of at least a portion of the bottom surface 11 is greater than the water contact angle of the first side surface 12, and the water roll-off angle of at least a portion of the bottom surface 11 is less than the water roll-off angle of the first side surface 12.

[0175] As can be seen from the foregoing, since the first flange 211 and the second flange 221 are not bonded together, condensate may reach the bottom surface 11 through the gap between the two flanges. Based on this, in addition to hydrophobically treating the first surface M1 to reduce the risk of condensate seeping into the bottom surface 11, this embodiment of the application can also hydrophobically treat the bottom surface 11. This allows condensate to quickly roll off the bottom surface 11 when it appears, thus also helping to reduce the adverse effects of condensate on the outer casing 10 and improving the reliability of the battery cell 500.

[0176] Secondly, embodiments of this application provide a battery device 100, which includes a battery cell 500 in any of the foregoing embodiments.

[0177] It should be noted that the battery device 100 provided in this application embodiment has the beneficial effects of the battery cell 500 in any of the aforementioned embodiments. For details, please refer to the aforementioned description of the beneficial effects of the battery cell 500. This application embodiment will not repeat the description.

[0178] In some embodiments, please refer to Figure 9 The battery device 100 also includes a heat dissipation assembly 40 surrounding the battery cell 500. The heat dissipation assembly 40 includes a first heat dissipation part 41 covering the second side 13. The first heat dissipation part 41 is recessed on the side facing the second surface to form an air supply channel 43.

[0179] The heat dissipation component 40 is arranged around the battery cell 500. On the one hand, the heat dissipation component 40 can provide insulation protection for the battery cell 500, and on the other hand, it can help the battery cell 500 dissipate heat. Specifically, the first heat dissipation part 41 is the part of the heat dissipation component 40 that covers the second side. The first heat dissipation part 41 is not a flat structure and is tightly fitted to the battery cell 500. The side of the first heat dissipation part 41 facing the second surface is recessed to form an air supply channel 43. The air supply channel 43 is connected to the external environment at both ends in the third direction Z. Ambient air can pass through the air supply channel 43 in the third direction Z and carry away some of the heat on the battery cell 500, thereby realizing the air cooling function of the battery cell 500.

[0180] The air supply channel 43 can have various sizes and shapes. Optionally, the first heat dissipation part 41 includes multiple reinforcing rib structures, with adjacent reinforcing rib structures spaced apart to form the air supply channel 43. The setting of the reinforcing rib structure can not only meet the formation requirements of the air supply channel 43, but also improve the structural strength of the heat dissipation component 40 and enhance the protection effect of the heat dissipation component 40 on the battery cell 500.

[0181] It should be noted that the heat dissipation assembly 40 also includes a second heat dissipation part 42 covering the first side 12, and the second heat dissipation part 42 can take various forms. Optionally, the second heat dissipation part 42 does not have a recess to form an air supply channel 43, and the second heat dissipation part 42 includes two independent parts, thereby facilitating the installation and removal of the heat dissipation assembly 40 and the battery cell 500.

[0182] The heat dissipation component 40 can meet the air cooling requirements of the battery cell 500. However, air cooling can easily lead to condensation on the battery cell 500. Therefore, this embodiment of the application hydrophobically treats the first surface M1 on the first flange 211, so that the water contact angle of at least a portion of the first surface M1 is greater than that of the second surface M2, and the water roll-off angle of at least a portion of the first surface M1 is less than that of the second surface M2. As a result, the first surface M1 has stronger hydrophobic properties, so that condensation will not wet the first surface M1 and can form water droplets and roll off quickly. This prevents condensation from moving to the outer casing 10 through the gap, thereby reducing the probability of insulation failure of the outer casing 10 and improving the reliability of the battery cell.

[0183] Thirdly, embodiments of this application provide an electrical device, which includes the battery device 100 in any of the foregoing embodiments.

[0184] Fourthly, please refer to Figure 10 This application provides a method for preparing a battery cell 500, the method comprising:

[0185] S100: Housing provided.

[0186] In step S100, the outer surface of the outer shell 10 has a bottom surface 11, a first side surface 12, and a second side surface 13, which are arranged at an angle to each other. Optionally, the area of ​​the second side surface 13 is larger than the area of ​​the first side surface 12, that is, the second side surface 13 is a large surface and the first side surface 12 is a narrow surface.

[0187] S110: The insulating film ring is placed on the outer periphery of the housing.

[0188] like Figure 4 and Figure 7 As shown, in step S110, the insulating film 20 includes a first portion 21 attached to the first side 12 and a second portion 22 attached to the second side 13. The first portion 21 extends beyond the first side 12 towards the bottom surface 11, and the second portion 22 extends beyond the second side 13 towards the bottom surface 11. The portion of the first portion 21 extending beyond the first side 12 is used to subsequently form a first flange 211, while the portion of the second portion 22 extending beyond the second side 13 is used to subsequently form a second flange 221.

[0189] S120: The portion of the first part that extends beyond the first side is bent.

[0190] like Figure 4 and Figure 8 As shown, in step S120, a first flange 211 is formed by bending and is attached to the bottom surface 11. The first flange 211 includes a first surface M1 facing away from the bottom surface 11. The first flange 211 can provide insulation protection at the intersection of the first side surface 12 and the second surface.

[0191] S130: The first surface is hydrophobically treated.

[0192] In step S130, the first surface M1 is hydrophobically treated to give it a larger water contact angle. Optionally, the water contact angle in at least a portion of the first surface M1 is α, where α ≥ 150°.

[0193] S140: The portion of the second part that extends beyond the first side is bent.

[0194] In step S140, a second flange 221 is formed by bending the first flange 211 on the side facing away from the bottom surface 11. The second flange 221 includes a second surface M2 facing away from the bottom surface 11. Since the second surface M2 is not hydrophobically treated, the water contact angle in at least a portion of the first surface M1 is greater than the water contact angle in the second surface M2.

[0195] In this embodiment, the first part 21 is first bent to form a first flange 211, and then the first surface M1 of the first flange 211 is hydrophobically treated. This eliminates the need to pre-determine the areas in the insulating film 20 that require hydrophobic treatment, allowing for precise hydrophobic treatment of the first surface M1. Furthermore, during the hydrophobic treatment process, the outer shell 10 provides support for the first flange 211, reducing the risk of deformation and thus simplifying the hydrophobic treatment process and improving manufacturing efficiency.

[0196] In some embodiments, please refer to Figure 11 In step S130, the following is included:

[0197] S131: Ion bombardment treatment is performed on the first surface.

[0198] In step S131, high-energy ions (such as oxygen, argon, and nitrogen) bombard the first surface M1 to physically etch the first surface M1, forming a micron or nano-scale uneven structure, i.e. an uneven micro-nano composite structure. The micro-nano composite structure can provide a better adhesion surface for chemical modification, making the final superhydrophobic surface more robust.

[0199] S132: Spray a hydrophobic agent onto the first surface.

[0200] In step S132, the first surface M1 can be chemically modified by spraying a low surface energy hydrophobic agent. Optionally, the hydrophobic agent includes fluorides (such as perfluoroalkyl compounds, fluorosilicone compounds), silane compounds (such as trimethylchlorosilane, methyltriethoxysilane), or other hydrophobic materials.

[0201] In this embodiment of the application, during the hydrophobic treatment process, high-energy ion bombardment is first used to physically etch the first surface M1, and then a hydrophobic agent is sprayed on the first surface M1. This method helps to form a robust superhydrophobic surface on the first surface M1, thereby improving the hydrophobic performance, reducing the risk of condensate coming into contact with the outer casing 10, and improving the reliability of the battery cell 500.

[0202] According to some embodiments of this application, please refer to Figures 4 to 8 The battery cell 500 includes a housing 10, an electrode assembly 30, and an insulating film 20. The outer surface of the housing 10 has a bottom surface 11, a first side surface 12, a second side surface 13, and a third side surface 14. The bottom surface 11, the first side surface 12, and the second side surface 13 are arranged at an angle. The second side surface 13 and the third side surface 14 are arranged side by side. The bottom surface 11, the first side surface 12, and the third side surface 14 are arranged at an angle. The area of ​​the second side surface 13 and the third side surface 14 is larger than the area of ​​the first side surface 12.

[0203] The insulating film 20 includes a first portion 21, a second portion 22, and a third portion 23. The first portion 21 is attached to the first side surface 12 and has a first flange 211 extending to the bottom surface 11. The second portion 22 is attached to the second side surface 13 and has a second flange 221 extending to the bottom surface 11. The third portion 23 is attached to the third side surface 14 and has a third flange 231 extending to the bottom surface 11. The second flange 221 is located on the side of the first flange 211 facing away from the bottom surface 11, and the first flange 211 and the second flange 221 partially overlap. The third flange 231 is located on the side of the second flange 221 facing away from the bottom surface 11, and the first flange 211 and the third flange 231 partially overlap.

[0204] The first flange 211 includes a first surface M1 facing away from the bottom surface 11, the second flange 221 includes a second surface M2 facing away from the bottom surface 11, and the third flange 231 includes a third surface M3 facing away from the bottom surface 11. The water contact angle of the entire area of ​​the first surface M1 is greater than the water contact angles of the second surface M2 and the third surface M3, and the water roll-off angle of the entire area of ​​the first surface M1 is less than the water roll-off angles of the second surface M2 and the third surface M3. Specifically, the water contact angle of the first surface M1 is α, where α ≥ 150°, and the water roll-off angle of the first surface M1 is b, where b ≤ 10°.

[0205] The first part 21 includes a body part 212 that is fitted to the first side surface 12. The body part 212 includes a fourth surface M4 that is away from the first side surface 12. The water contact angle in at least a portion of the first surface M1 is greater than the water contact angle of the fourth surface M4, and the water roll-off angle in at least a portion of the first surface M1 is less than the water roll-off angle of the fourth surface M4.

[0206] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. 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, characterized in that, include: The outer casing has a bottom surface, a first side surface, and a second side surface, wherein the bottom surface, the first side surface, and the second side surface are arranged at an angle to each other. Electrode assembly, housed within the housing; An insulating film is disposed on the outer surface of the housing. The insulating film includes a first part and a second part. The first part is attached to the first side and has a first flange extending to the bottom surface. The second part is attached to the second side and has a second flange extending to the bottom surface. The second flange is located on the side of the first flange facing away from the bottom surface, and the first flange and the second flange partially overlap. Wherein, the first flange includes a first surface away from the bottom surface, the second flange includes a second surface away from the bottom surface, the water contact angle in at least a portion of the first surface is greater than the water contact angle in the second surface, and the water roll-off angle in at least a portion of the first surface is less than the water roll-off angle in the second surface; The first surface includes a first overlapping region that overlaps with the second flange. The first overlapping region is hydrophobically treated so that the water contact angle of the first overlapping region is greater than the water contact angle of the second surface, and the water roll-off angle of the first overlapping region is less than the water roll-off angle of the second surface.

2. The battery cell according to claim 1, characterized in that, The area of ​​the second side is larger than the area of ​​the first side, and part of the structure of the second flange is attached to the first surface and part of the structure is attached to the bottom surface.

3. The battery cell according to claim 2, characterized in that, The outer surface of the outer shell has a third side side arranged side-by-side with the second side side, and the bottom surface, the first side side and the third side side are arranged at an angle to each other, and the area of ​​the third side side is larger than the area of ​​the first side side; The insulating film further includes a third part, which is attached to the third side surface and has a third flange extending to the bottom surface. The third flange is located on the side of the second flange facing away from the bottom surface, and the first flange partially overlaps with the third flange. The third flange includes a third surface facing away from the bottom surface, wherein the water contact angle in at least a portion of the first surface is greater than the water contact angle of the third surface.

4. The battery cell according to claim 3, characterized in that, The first surface includes a second overlapping region that overlaps with the third flange, wherein the water contact angle of the second overlapping region is greater than the water contact angle of the third surface, and the water roll-off angle of the second overlapping region is less than the water roll-off angle of the third surface.

5. The battery cell according to claim 4, characterized in that, The water contact angle of all regions in the first surface is greater than that of the second surface, and the water roll-off angle of all regions in the first surface is less than that of the second surface.

6. The battery cell according to claim 1, characterized in that, The first part includes a body portion that is fitted to the first side surface. The body portion includes a fourth surface that is away from the first side surface. The water contact angle in at least a portion of the first surface is greater than the water contact angle of the fourth surface, and the water roll-off angle in at least a portion of the first surface is less than the water roll-off angle of the fourth surface.

7. The battery cell according to claim 1, characterized in that, The water contact angle in at least a portion of the first surface is α, where α satisfies: α ≥ 150°; and / or, The water roll-off angle in at least a portion of the first surface is b, where b ≤ 10°.

8. The battery cell according to claim 1, characterized in that, The second flange includes a fifth surface facing the bottom surface, the water contact angle of the fifth surface being greater than that of the second surface, and the water roll-off angle of the fifth surface being less than that of the second surface.

9. The battery cell according to claim 8, characterized in that, The second flange includes a first portion and a second portion that are bent and stacked, with the second portion located on the side of the first portion that faces away from the bottom surface; The first portion includes the fifth surface and is connected to the first flange bend.

10. The battery cell according to claim 1, characterized in that, The water contact angle of at least a portion of the bottom surface is greater than the water contact angle of the first side surface, and the water roll-off angle of at least a portion of the bottom surface is less than the water roll-off angle of the first side surface.

11. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-10.

12. The battery device according to claim 11, characterized in that, It also includes a heat dissipation assembly surrounding the battery cell, the heat dissipation assembly including a first heat dissipation part covering the second side, the first heat dissipation part being recessed on the side facing the second surface to form an air supply channel.

13. An electrical appliance, characterized in that, Includes the battery device as described in claim 11 or 12.

14. A method for preparing a single battery cell, characterized in that, include: A housing is provided, the outer surface of which has a bottom surface, a first side surface, and a second side surface, wherein the bottom surface, the first side surface, and the second side surface are arranged at an angle to each other. An insulating film is arranged around the outer periphery of the housing. The insulating film includes a first portion attached to the first side and a second portion attached to the second side. The first portion extends beyond the first side towards the bottom surface, and the second portion extends beyond the second side towards the bottom surface. The portion of the first part that extends beyond the first side is bent to form a first flange attached to the bottom surface, the first flange including a first surface facing away from the bottom surface; The first surface is subjected to a hydrophobic treatment; The portion of the second part that extends beyond the first side is bent to form a second flange attached to the side of the first flange facing away from the bottom surface; In the step of hydrophobizing the first surface, the first surface includes a first overlapping region that overlaps with the second flange, and the first overlapping region is hydrophobized.

15. The preparation method according to claim 14, characterized in that, The step of hydrophobizing the first surface includes: The first surface is subjected to ion bombardment treatment to form an uneven micro-nano composite structure on the first surface; A hydrophobic agent is sprayed onto the first surface.

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