Battery cell, battery device, and electric device

Abstract

The application provides a battery cell, a battery device and a power utilization device. The battery cell comprises a shell, an electrode assembly, an electrode terminal and a sealing member. The shell comprises a wall portion, and the wall portion is provided with an electrode lead-out hole. The electrode assembly is arranged in the shell, and the electrode assembly comprises a tab. The electrode terminal is at least partially accommodated in the electrode lead-out hole, and the electrode terminal is electrically connected to the tab. The sealing member comprises a first sealing portion which is accommodated in the electrode lead-out hole and surrounds the electrode terminal. At least part of the first sealing portion is clamped between the electrode terminal and the hole wall of the electrode lead-out hole in the radial direction of the electrode lead-out hole. In the direction in which the electrode assembly points to the wall portion, the size of the sealing member in the radial direction of the electrode lead-out hole gradually increases.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. 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 sealing reliability of individual battery cells has become a research direction. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device, and an electrical device that can improve the sealing reliability of the battery cell.

[0005] On one hand, embodiments of this application provide a battery cell including a casing, an electrode assembly, electrode terminals, and a seal. The casing includes a wall portion with an electrode lead-out hole. The electrode assembly is disposed within the casing and includes tabs. At least a portion of the electrode terminals is accommodated in the electrode lead-out hole and electrically connected to the tabs. The seal includes a first sealing portion accommodated within the electrode lead-out hole and surrounding the electrode terminals. Along the radial direction of the electrode lead-out hole, at least a portion of the first sealing portion is sandwiched between the electrode terminals and the hole wall of the electrode lead-out hole. Along the direction from the electrode assembly to the wall portion, the size of the seal gradually increases in the radial direction of the electrode lead-out hole.

[0006] In the above scheme, the electrode terminals are typically installed on the wall via riveting or other methods. During the assembly process between the electrode terminals and the wall, the seal is prone to movement towards the electrode assembly due to stress and other factors. Furthermore, since the first sealing part is subjected to the combined clamping and compression of the electrode terminals and the wall, and its radial dimension gradually increases in the direction away from the electrode assembly, the closer the first sealing part moves to the electrode assembly, the greater the compression from the electrode terminals and the wall. This enhances the contact strength between the first sealing part and the electrode terminals and the wall, thereby improving the sealing effect and hindering further axial movement of the seal, achieving a self-sealing effect. Here, "self-sealing" refers to the seal's ability to enhance its sealing performance as it moves towards the electrode assembly relative to the wall, thanks to its unique shape and dimensional design.

[0007] Furthermore, during the use or transportation of the battery cell, the electrode terminals may have a certain tendency to move relative to the wall. For example, the electrode terminals may tend to move towards the electrode assembly relative to the wall due to external forces, shaking, and gravity. Since a portion of the structure in the first sealing part is in close contact with the electrode terminals, the electrode terminals will also cause the first sealing part to tend to move towards the electrode assembly. In this case, due to the special size and shape design of the first sealing part in the embodiment of this application, it is difficult for the sealing part to continue moving axially, and the sealing part also helps to prevent the electrode terminals from moving relative to the wall, thereby achieving both sealing effect and improving the relative positional reliability between the wall and the electrode terminals.

[0008] In some embodiments, the size of the electrode lead-out hole gradually increases in the radial direction away from the electrode assembly.

[0009] In the above scheme, in addition to adjusting the size and shape of the first sealing part in the seal, the size and shape of the electrode lead-out hole are also adjusted so that the radial gap between the electrode terminal and the hole wall is smaller the closer to the electrode assembly. Based on this, if the first sealing part moves towards the electrode assembly relative to the wall, due to the change in the gap size and the radial dimension of the first sealing part itself, the first sealing part will be subjected to a greater squeezing force from the electrode terminal and the wall, thereby improving the sealing effect of the seal and hindering further axial movement of the seal, thus balancing the sealing performance and relative positional reliability of the seal.

[0010] In some embodiments, the first sealing portion includes a first sub-portion and a second sub-portion located on the side of the first sub-portion away from the electrode assembly. The first sub-portion includes a first outer peripheral surface, and the second sub-portion includes a second outer peripheral surface. The first outer peripheral surface is spaced apart from the hole wall to form a gap space, and the second outer peripheral surface is in contact with the hole wall.

[0011] In the above scheme, when the seal is subjected to factors such as electrode terminal assembly and the relative wall moves towards the electrode assembly, part of the structure in the second sub-section will move downward, causing the size of the gap space to be compressed. The second sub-section is subjected to increased compressive stress from the electrode terminal and the wall, thereby improving the sealing effect and hindering the seal from continuing to move in the axial direction, thus taking into account both the sealing performance of the seal and the reliability of the relative position.

[0012] Furthermore, as the seal moves toward the electrode assembly, a portion of the structure in the first sub-part near the second sub-part also comes into contact with the bore wall. That is, the first outer peripheral surface of the first sub-part is not completely spaced from the bore wall, which also improves the sealing effect.

[0013] In some embodiments, the inclination angle of the first outer peripheral surface relative to the axial direction is a1, and the inclination angle of the hole wall relative to the axial direction is a2; wherein a1 and a2 satisfy: a1 > a2.

[0014] In the above scheme, when designing the seal, the first and second outer peripheral surfaces have the same inclination angle 'a1', both greater than the inclination angle 'a2' of the hole wall. During the assembly of the electrode terminal and the wall, the second outer peripheral surface will interfere with the hole wall due to the larger inclination angle. This causes the second sub-part to deform under pressure from the electrode terminal and the wall, resulting in radial compression of the second sub-part and causing the second outer peripheral surface to come into contact with the hole wall. This design helps to increase the degree of compression of the second sub-part, improving both the sealing effect and the relative positional reliability between the seal and the wall.

[0015] In some embodiments, 3°≤a1-a2≤15°.

[0016] In the above scheme, by setting a1-a2 to not less than 3°, the first outer peripheral surface has a larger angle difference with the hole wall. This helps to reduce the interference between the second outer peripheral surface and the hole wall, causing the second sub-part to be subjected to greater compressive stress from the electrode terminal and the wall, thereby increasing the contact strength of the second sub-part relative to the electrode terminal and the wall, enhancing the sealing effect, and improving the relative positional reliability between the seal and the wall. Furthermore, by setting a1-a2 to not more than 15°, the radial compression of the second sub-part is alleviated, thereby reducing the risk of cracking due to excessive compression and improving the structural reliability of the seal.

[0017] In some embodiments, the battery cell further includes a first insulating member, which is at least partially disposed between the wall portion and the electrode assembly and in contact with the first sub-portion.

[0018] In the above scheme, the seal and the first insulating member do not make contact inside the housing, but at the opening of the electrode lead hole or inside the electrode lead hole. Thus, the seal does not extend to the side of the wall facing the electrode assembly, meaning that the presence of the seal does not occupy the internal space of the housing, which helps to improve the energy density of the battery cell.

[0019] In some embodiments, the electrode terminal includes a first terminal portion, a second terminal portion, and a third terminal portion. The first terminal portion is located on the side of the wall portion facing the electrode assembly, and the third terminal portion is located on the side of the wall portion away from the electrode assembly. A portion of the wall portion is located between the first terminal portion and the third terminal portion. The second terminal portion is connected to the first terminal portion and the third terminal portion, and the second terminal portion is at least partially accommodated in the electrode lead-out hole.

[0020] The first insulating member includes a first insulating portion located on the side of the first terminal portion facing away from the electrode assembly, the first insulating portion being partially located within the electrode lead-out hole and in contact with the first sub-portion. Alternatively, the electrode lead-out hole includes a first opening facing the electrode assembly, with the first insulating portion contacting the first sub-portion at the first opening.

[0021] In the above scheme, the seal does not extend into the housing, which helps to improve the energy density of the battery cell. Furthermore, due to the design of the varying radial dimensions of the first seal, the end of the first sub-part facing the electrode assembly often has a smaller end face area. Based on this, by changing the size and shape of the first insulating member, the first insulating member includes a first insulating portion, and the first insulating portion is used to contact the first terminal portion, rather than the first sub-part contacting the first terminal portion. This helps to increase the contact area and improve the contact strength, thereby improving the insulation reliability between the first terminal portion and the wall portion.

[0022] In some embodiments, the first insulating portion is disposed in contact with the outer peripheral surface of the second terminal portion.

[0023] In the above solution, by contacting the outer peripheral surface of the first insulating portion and the second terminal portion, the overlap area between the orthographic projection of the first insulating portion and the orthographic projection of the first terminal portion in the projection plane perpendicular to the axial direction can be increased, thereby further increasing the contact area between the first insulating portion and the first terminal portion and improving the insulation reliability between the wall portion and the first terminal portion. Furthermore, by providing the first insulating portion around and in contact with the second terminal portion, the insulation reliability between the second terminal portion and the wall portion can be improved by means of the first insulating portion.

[0024] In some embodiments, the seal is sandwiched between the third terminal portion and the first insulating member.

[0025] In the above scheme, the third terminal and the first insulating member can jointly compress the seal in the axial direction, causing the seal to expand radially, thereby improving the sealing performance. Simultaneously, during the electrode terminal assembly process, due to the riveting process, the seal tends to move closer to the electrode assembly, thus increasing the interference between the second terminal and the wall of the electrode lead-out hole, thereby enhancing the sealing effect.

[0026] In some embodiments, the seal includes a second sealing portion connected to the first sealing portion and located on the side of the first sealing portion away from the electrode assembly. The second sealing portion is radially larger than the first sealing portion. Axially, a portion of the second sealing portion is sandwiched between the wall portion and the electrode terminal.

[0027] In the above scheme, the second sealing part is a structure located outside the electrode lead-out hole in the sealing element. Furthermore, by setting the radial dimension of the second sealing part to be larger than that of the first sealing part, the second sealing part will not penetrate into the electrode lead-out hole even under external force, thereby improving the positional reliability of the sealing element relative to the wall. In addition, the second sealing part is subjected to axial clamping and compression by the electrode terminal and the wall, which further helps to improve sealing reliability and reduce the risk of external dust and impurities entering the housing and electrolyte transferring to the external environment.

[0028] In some embodiments, the battery cell further includes a second insulating member disposed on the side of the wall away from the electrode assembly. The second insulating member has a through hole that communicates with the electrode lead-out hole. A second sealing portion is located in the through hole and is disposed in contact with the second insulating member.

[0029] In the above scheme, since the end of the seal facing away from the electrode assembly has a large end face area, the end of the seal facing away from the electrode assembly can be extended beyond the electrode lead hole to form a second sealing part. The second sealing part and the second insulating part are arranged to contact each other radially. In this way, the second sealing part and the second insulating part can contact the third terminal part axially, thereby improving the insulation effect between the third terminal part and the wall part. At the same time, when riveting process and external force occur, the third terminal part can directly transfer stress to the second sealing part and make the seal self-sealing, thereby improving the sealing effect.

[0030] In some embodiments, the material of the seal includes polytetrafluoroethylene, perfluoroalkoxy vinyl ether copolymer, polychlorotrifluoroethylene, polyetheretherketone, or polyimide.

[0031] In the above scheme, polytetrafluoroethylene, perfluoroalkoxy vinyl ether copolymer, polychlorotrifluoroethylene, polyether ether ketone, and polyimide can all resist the corrosion of electrolyte. By setting the material of the sealing element to one of the above, it is helpful to use its dense molecular structure and hydrophobicity to block water vapor, reduce the risk of external water vapor entering the shell and electrolyte penetrating out of the shell. At the same time, these materials have a certain structural strength, which can increase the difficulty of deformation of the sealing element and make the sealing element in close contact with the hole wall of the electrode lead-out hole and the electrode terminal, thereby improving the sealing effect.

[0032] Secondly, embodiments of this application provide a battery device, which includes a single battery cell in any of the foregoing embodiments.

[0033] Thirdly, embodiments of this application provide an electrical device, which includes the battery device in any of the foregoing embodiments.

[0034] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0035] 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.

[0036] Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the structure of a battery device provided in some embodiments of this application;

[0038] 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;

[0039] Figure 4 This is a cross-sectional structural diagram of a battery cell provided in some embodiments of this application;

[0040] Figure 5 yes Figure 4 A magnified structural relationship diagram at point Q in the middle region;

[0041] Figure 6 yes Figure 5 A magnified structural diagram of region P in the middle area;

[0042] Figure 7 This is a cross-sectional structural diagram of a seal in a battery cell provided in some embodiments of this application;

[0043] Figure 8 This application provides a partial cross-sectional structural diagram of a battery cell according to some embodiments.

[0044] Tag name:

[0045] 10. Outer shell; 11. Wall; 12. Electrode lead-out hole; 121. First opening;

[0046] 20. Electrode assembly; 21. Electrode tab;

[0047] 30. Electrode terminal; 31. First terminal portion; 32. Second terminal portion; 33. Third terminal portion; 331. First section; 332. Second section;

[0048] 40. Seal; 41. First sealing part; 411. First sub-part; 412. Second sub-part; 42. Second sealing part; 421. Third sub-part; 422. Fourth sub-part;

[0049] 50. First insulating element; 51. First insulating part; 52. Second insulating part;

[0050] 60. Second insulating component; 61. Through hole;

[0051] J. Gap space;

[0052] M1, first outer peripheral surface; M2, second outer peripheral surface;

[0053] X, axial direction. Detailed Implementation

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] Unless otherwise specified, all embodiments and optional embodiments of this application can be combined to form new technical solutions.

[0059] Unless otherwise specified, all technical features and optional technical features of this application may be combined to form new technical solutions.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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.).

[0071] 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 The following are included: 0.25Mn0.25O2 (also known as NCM211), LiNi0.6Co0.2Mn0.2O2 (also known as NCM622), LiNi0.8Co0.1Mn0.1O2 (also known as NCM811), lithium nickel cobalt aluminum oxides (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.

[0072] 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.

[0073] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0074] 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.).

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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.

[0079] As an example, negative electrode active materials can be filled or / and deposited within the negative electrode current collector.

[0080] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0081] 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 a liquid electrolyte solution and includes an electrolyte salt and a solvent.

[0082] 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.

[0083] 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.

[0084] 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.

[0085] The electrode assembly can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0086] In some implementations, the electrode assembly is a wound structure. The positive and negative electrode sheets are wound into a wound structure.

[0087] In some implementations, the electrode assembly is a stacked structure.

[0088] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0089] 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.

[0090] As an example, both the positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0091] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0092] As an example, the separator can be set continuously, either by folding or rolling between any adjacent positive or negative electrode plates.

[0093] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0094] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly 20. The tabs 21 include a positive tab 21 and a negative tab 21.

[0095] In some embodiments, the battery cell may include a casing. The casing 10 may be a steel casing, an aluminum casing, a plastic casing (such as polypropylene), a composite metal casing (such as a copper-aluminum composite casing 10), or an aluminum-plastic film, etc. In some embodiments, the casing 10 may be a sealed structure or a non-sealed structure. As an example, when the casing 10 is a non-sealed structure, the casing 10 serves to protect the electrode assembly 20, and a sealing bag is included between the casing 10 and the electrode assembly 20. The sealing bag is used to encapsulate the electrode assembly 20 and the electrolyte. Specifically, the sealing bag may be a bag-shaped insulating component or an aluminum-plastic film. When the casing 10 is a sealed structure, it is used to encapsulate the electrode assembly 20 and the electrolyte, etc.

[0096] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0097] 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.

[0098] 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.

[0099] In some embodiments, the battery cell further includes a lower plastic layer disposed on the side of the end cap facing inwards from the housing. The lower plastic layer can be pre-formed as a single piece of plastic or assembled from various plastic components. The material of the lower plastic layer may include insulating material to provide insulation performance and improve electrical insulation between the internal components and the end cap. Furthermore, the lower plastic layer can also abut against the electrode assembly to fix and protect the electrode assembly, reducing the risk of open circuits due to displacement of the electrode assembly and other components during battery cell transportation and use, especially in vibrating environments.

[0100] In some embodiments, the battery cell further includes an upper plastic layer disposed on the side of the end cap away from the interior of the housing. Similar to the lower plastic layer, the upper plastic layer can be pre-formed as a single piece of plastic or assembled from various plastic components. The material of the upper plastic layer may include insulating material to provide insulation performance and improve the electrical insulation between the electrode terminals and the end cap.

[0101] 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.

[0102] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] In some embodiments, the battery device may be an energy storage device. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0111] In a single battery cell, the electrode assembly is typically housed within the casing, which includes electrode lead-out holes and electrode terminals to enable electrical connection between the electrode assembly and external components. To reduce the risk of external dust and other impurities entering the casing and contaminating the electrolyte, a seal is usually installed at the electrode lead-out holes. This seal is at least partially sandwiched between the casing and the electrode terminals to ensure a good seal. However, existing seals often suffer from insufficient sealing performance.

[0112] In view of this, embodiments of this application provide a battery cell, a battery device, and an electrical device. By adjusting the size and shape of the seal, the seal can simultaneously achieve a dual sealing effect of axial and radial sealing, improving sealing reliability and the reliability of the battery cell. Furthermore, a buffer space can be formed near the connection portion to reduce the risk of cracking of the first and second sub-parts due to excessive compression, thus improving the reliability of the seal. In addition, the seal 40 under this design can adaptively adjust according to pressure changes, so that when the pressure on the seal increases, the seal can further expand radially and axially in the electrode lead-out hole, thereby enhancing the sealing tightness.

[0113] 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.

[0114] 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.

[0115] Please see Figure 1 , Figure 1This 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.

[0116] Please refer to Figure 2 , Figure 2 This 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), with the individual battery cells housed within the housing 400. The housing 400 is used to house the individual 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 individual 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.

[0117] 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.

[0118] Figure 3 for Figure 2The 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.

[0119] 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 7 The battery cell 500 includes a housing 10, an electrode assembly 20, an electrode terminal 30, and a seal 40. The housing 10 includes a wall portion 11, which is provided with an electrode lead-out hole 12. The electrode assembly 20 is disposed inside the housing 10 and includes a tab 21. The electrode terminal 30 is at least partially accommodated in the electrode lead-out hole 12 and is electrically connected to the tab 21.

[0120] The seal 40 includes a first sealing portion 41 that is received within the electrode lead-out hole 12 and surrounds the electrode terminal 30. At least a portion of the first sealing portion 41 is sandwiched between the electrode terminal 30 and the hole wall of the electrode lead-out hole 12 along the radial direction of the electrode assembly 20 pointing towards the wall portion 11. The size of the seal 40 in the radial direction of the electrode lead-out hole 12 gradually increases.

[0121] The outer casing 10 is a shell structure in the battery cell 500 used to house and protect other components. The outer casing 10 has a hollow structure and includes multiple shell wall structures. Optionally, the outer casing 10 can be in the shape of a cylinder, cuboid, or prism. Wall 11 is one of the shell wall structures on the outer casing 10. Optionally, the outer casing 10 includes a housing and an end cap. The housing has an opening, and the end cap closes at the opening of the housing. The wall 11 can be an end cap, or it can be a shell wall structure on the housing. The attached figure shows the case where the wall 11 is an end cap.

[0122] The electrode assembly 20 is disposed within the housing 10. The electrode assembly 20 is a core component of the battery cell 500 used to realize charging and discharging functions. The electrode assembly 20 can be formed by winding or stacking multiple layers of electrode sheets. Optionally, the electrode assembly 20 includes an electrode body and tabs 21. The electrode body is the main component of the electrode assembly 20, and the tabs 21 are components in the electrode assembly 20 used for electrical connection to the electrode terminals 30. The electrode assembly 20 may include two tabs 21, with at least one tab 21 extending from the end of the electrode body facing the wall 11 to achieve electrical connection with the electrode terminals 30 located on the wall 11.

[0123] The electrode terminal 30 is used to realize the electrical connection between the battery cell 500 and other external structures, and the electrode terminal 30 is fixed to the wall portion 11. The electrode terminal 30 is electrically connected to the tab 21, wherein the electrode terminal 30 can be directly connected to the tab 21, or the battery cell 500 can also include a current collector, and the electrode terminal 30 is indirectly connected to the tab 21 through the current collector.

[0124] The wall portion 11 is provided with an electrode lead-out hole 12, which extends through the wall portion 11 along its thickness direction, i.e., the axial direction X of the electrode lead-out hole 12 is parallel to the thickness direction of the wall portion 11. The electrode terminal 30 extends to the outside of the housing 10 through the electrode lead-out hole 12. The shape of the electrode lead-out hole 12 can match the shape of the electrode terminal 30, or the shape of the electrode lead-out hole 12 can be designed to not match the shape of the electrode assembly 20.

[0125] The seal 40 is a component in the battery cell 500 that performs a sealing function. The first sealing part 41 is a portion of the seal 40 located within the electrode lead-out hole 12. The seal 40 may consist only of the first sealing part 41, or it may include other sealing parts besides the first sealing part 41. In other words, the seal 40 may be completely located within the electrode lead-out hole 12, or it may be partially located within and partially located outside the electrode lead-out hole 12.

[0126] Along the radial direction of the electrode lead-out hole 12, at least a portion of the first sealing part 41 is sandwiched between the electrode terminal 30 and the hole wall. The term "sandwiched" here means that at least a portion of the structure of the first sealing part 41 is in close contact with both the electrode terminal 30 and the hole wall, that is, at least a portion of the structure of the first sealing part 41 is subjected to the joint clamping and compression of the electrode terminal 30 and the wall 11.

[0127] It should be noted that the "radial direction of electrode lead-out hole 12" mentioned here refers to any direction perpendicular to the axial direction X, that is, any direction perpendicular to the axial direction X. It does not constitute a limitation on the shape of electrode lead-out hole 12. In other words, electrode lead-out hole 12 can be a circular hole, a square hole, or a prism-shaped hole, etc.

[0128] Furthermore, all structures in the first sealing portion 41 can simultaneously contact the electrode terminal 30 and the hole wall, or some structures in the first sealing portion 41 can simultaneously contact the electrode terminal 30 and the hole wall, while the remaining structures are spaced apart from at least one of the electrode terminal 30 and the hole wall. Optionally, such as Figure 6 As shown, a portion of the structure in the first sealing part 41 is in contact with both the electrode terminal 30 and the hole wall, while the remaining portion of the structure in the first sealing part 41 is spaced apart from the hole wall.

[0129] Along the direction from the electrode assembly 20 to the wall portion 11, the radial dimension of the first sealing portion 41 in the electrode lead-out hole 12 gradually increases; that is, the farther away from the electrode assembly 20, the larger the radial dimension of the first sealing portion 41. The "trend" mentioned here refers to the tendency of the radial dimension of the first sealing portion 41 to change accordingly. In other words, it is sufficient that the first sealing portion 41 as a whole has a tendency to increase in radial dimension in the direction away from the electrode assembly 20; it does not mean that the corresponding radial dimension of the first sealing portion 41 at any different position must remain different.

[0130] Electrode terminals 30 are typically mounted to the wall portion 11 via riveting or other methods. During the assembly process between the electrode terminals 30 and the wall portion 11, the seal 40 is prone to movement towards the electrode assembly 20 due to stress and other factors. Furthermore, since the first sealing portion 41 is subjected to the combined clamping and compression of the electrode terminals 30 and the wall portion 11, and the radial dimension of the first sealing portion 41 gradually increases in the direction away from the electrode assembly 20, the closer the first sealing portion 41 moves to the electrode assembly 20, the greater the compression force exerted on it by the electrode terminals 30 and the wall portion 11. This enhances the contact strength between the first sealing portion 41 and the electrode terminals 30 and the wall portion 11, thereby improving the sealing effect of the seal 40 and hindering its further movement in the axial direction X, achieving a self-sealing effect. Here, "self-sealing" refers to the seal 40's ability to enhance its sealing performance as it moves towards the electrode assembly 20 relative to the wall portion 11, thanks to its unique shape and dimensional design.

[0131] Furthermore, during the use or transportation of the battery cell 500, the electrode terminal 30 may have a certain tendency to move relative to the wall 11. For example, the electrode terminal 30 may tend to move towards the electrode assembly 20 relative to the wall 11 due to external forces, shaking, and gravity. Since a portion of the structure in the first sealing portion 41 is in close contact with the electrode terminal 30, the electrode terminal 30 will also cause the first sealing portion 41 to tend to move towards the electrode assembly 20. In this case, due to the special size and shape design of the first sealing portion 41 in the embodiment of this application, it is difficult for the sealing portion 40 to continue moving along the axial direction X. The sealing portion 40 also helps to prevent the electrode terminal 30 from moving relative to the wall 11, thereby achieving both sealing effect and improving the relative positional reliability between the wall 11 and the electrode terminal 30.

[0132] It should be noted that, Figures 4 to 6 The sealing element 40 is the sealing element 40 after the opposite wall portion 11 and the electrode terminal 30 are assembled. Figure 7 The seal 40 in the middle is the seal 40 before assembly, that is Figure 7 The dimensions and shape of the sealing element 40 correspond to the actual design stage of the sealing element 40. By comparing the first sealing portion 41 of the sealing element 40 in the two figures, it can be seen that at least a portion of the structure in the first sealing portion 41 will deform due to the combined clamping and compression by the electrode terminal 30 and the wall portion 11, so that its shape and dimensions match the shape and dimensions of the gap between the electrode terminal 30 and the wall portion 11. Based on this, the sealing element 40 mentioned in the embodiments of this application refers to... Figures 4 to 6 The sealing element 40 in the middle is the sealing element 40 after the opposite wall portion 11 and the electrode terminal 30 are assembled.

[0133] In some embodiments, such as Figures 4 to 6 As shown, the size of the electrode lead-out hole 12 gradually increases in the radial direction away from the electrode assembly 20.

[0134] The closer to the electrode assembly 20, the smaller the radial dimension of the electrode lead-out hole 12; the farther away from the electrode assembly 20, the larger the radial dimension of the electrode lead-out hole 12. For example, the cross-sectional shape of the electrode lead-out hole 12 can be an inverted trapezoidal structure.

[0135] In this embodiment, in addition to adjusting the size and shape of the first sealing portion 41 in the seal 40, the size and shape of the electrode lead-out hole 12 are also adjusted so that the radial gap between the electrode terminal 30 and the hole wall is smaller the closer it is to the electrode assembly 20. Based on this, if the first sealing portion 41 moves closer to the electrode assembly 20 relative to the wall portion 11, due to the change in the gap size and the radial dimension of the first sealing portion 41 itself, the first sealing portion 41 will be subjected to a greater squeezing force from the electrode terminal 30 and the wall portion 11, thereby improving the sealing effect of the seal 40 and hindering further movement of the seal 40 in the axial direction X, thus balancing the sealing performance and relative position reliability of the seal 40.

[0136] In some embodiments, such as Figures 4 to 6 As shown, the first sealing part 41 includes a first sub-part 411 and a second sub-part 412 located on the side of the first sub-part 411 away from the electrode assembly 20. The first sub-part 411 includes a first outer peripheral surface M1, and the second sub-part 412 includes a second outer peripheral surface M2. The first outer peripheral surface M1 and the hole wall are spaced apart to form a gap space J, and the second outer peripheral surface M2 is in contact with the hole wall.

[0137] The first sub-part 411 and the second sub-part 412 can be an integral structure, both located within the electrode lead-out hole 12. Both the first sub-part 411 and the second sub-part 412 are in contact with the electrode terminal 30, but the difference is that the first sub-part 411 is spaced apart from the hole wall, while the second sub-part 412 is in contact with the hole wall.

[0138] The first outer peripheral surface M1 is the outer peripheral surface of the first sub-part 411. The first outer peripheral surface M1 and the hole wall are spaced apart to form a gap space J. The second outer peripheral surface M2 is the outer peripheral surface of the second sub-part 412. The second outer peripheral surface M2 is in contact with the hole wall. Therefore, the size and shape of the second outer peripheral surface M2 match the size and shape of the hole wall.

[0139] Referring to the accompanying drawings, when the seal 40 is subjected to factors such as the assembly of the electrode terminal 30 and moves towards the electrode assembly 20 relative to the wall 11, a portion of the structure in the second sub-part 412 moves downward, causing the size of the gap space J to be compressed. The second sub-part 412 is subjected to increased compressive stress from the electrode terminal 30 and the wall 11, thereby improving the sealing effect and hindering the seal 40 from continuing to move in the axial direction X, thus balancing the sealing performance of the seal 40 and the reliability of its relative position.

[0140] Furthermore, when the seal 40 moves toward the electrode assembly 20, a portion of the structure of the first sub-part 411 near the second sub-part 412 will also come into contact with the hole wall. That is, the first outer peripheral surface M1 of the first sub-part 411 is not completely spaced apart from the hole wall, which can also improve the sealing effect.

[0141] It should be noted that although both the first sub-part 411 and the second sub-part 412 are in contact with the electrode terminal 30, the second sub-part 412 is subjected to greater contact stress due to the combined compression from the wall 11 and the electrode terminal 30. Based on this, the seal 40 can use this contact stress to impede the movement of the electrode terminal 30 relative to the wall 11, thereby enhancing the reliability of the relative position between the electrode terminal 30, the seal 40, and the wall 11.

[0142] In some embodiments, the inclination angle of the first outer peripheral surface M1 relative to the axial direction X is a1, and the inclination angle of the hole wall relative to the axial direction X is a2; wherein a1 and a2 satisfy: a1 > a2. Since the hole wall is fitted to the second outer peripheral surface M2, a2 ​​also represents the inclination angle of the second outer peripheral surface M2 relative to the axial direction X.

[0143] Optionally, when designing seal 40, such as Figure 7 As shown, the first outer peripheral surface M1 and the second outer peripheral surface M2 are coplanar, meaning they have the same inclination angle. However, during the assembly of the electrode terminal 30 and the wall portion 11, the second sub-part 412 is deformed by the pressure from the electrode terminal 30 and the wall portion 11, causing the second outer peripheral surface M2 to adhere to the hole wall. Consequently, the second outer peripheral surface M2 and the first outer peripheral surface M1 are no longer coplanar. At this point, as... Figure 6 As shown, the first outer peripheral surface M1 corresponds to the tilt angle a1, and the second outer peripheral surface M2 corresponds to the tilt angle a2.

[0144] In summary, in the embodiments of this application, when designing the sealing element 40, the first outer peripheral surface M1 and the second outer peripheral surface M2 have the same inclination angle α1, both of which are greater than the inclination angle α2 of the hole wall. Thus, during the assembly process of the electrode terminal 30 and the wall portion 11, the second outer peripheral surface M2 will interfere with the hole wall due to its larger inclination angle. This causes the second sub-part 412 to be deformed by the pressure from the electrode terminal 30 and the wall portion 11, resulting in radial compression of the second sub-part 412 and causing the second outer peripheral surface M2 to contact and adhere to the hole wall. This design helps to increase the degree of compression of the second sub-part 412, improving the sealing effect while also enhancing the relative positional reliability between the sealing element 40 and the wall portion 11.

[0145] In some embodiments, 3° ≤ a1-a2 ≤ 15°. Optionally, a1-a2 is one of 3°, 5°, 8°, 10°, 12°, and 15°.

[0146] In this embodiment, by setting a1-a2 to not less than 3°, the first outer peripheral surface M1 has a larger angle difference with the hole wall. This helps to reduce the interference between the second outer peripheral surface M2 and the hole wall, resulting in greater compressive stress on the second sub-part 412 from the electrode terminal 30 and the wall 11. This increases the contact strength of the second sub-part 412 relative to the electrode terminal 30 and the wall 11, enhancing the sealing effect and the relative positional reliability between the seal 40 and the wall 11. Furthermore, by setting a1-a2 to not more than 15°, the radial compression of the second sub-part 412 is alleviated, thereby reducing the risk of cracking due to excessive compression and improving the structural reliability of the seal 40.

[0147] In some embodiments, such as Figure 5 and Figure 6 As shown, the battery cell 500 also includes a first insulating member 50, which is at least partially disposed between the wall portion 11 and the electrode assembly 20 and is in contact with the first sub-portion 411.

[0148] The first insulating member 50 serves at least to achieve electrical insulation between the wall portion 11 and the electrode assembly 20. Exemplarily, the first insulating member 50 is a lower plastic component, which is pre-molded integrally from plastic or assembled from various plastic parts. Furthermore, in the axial direction X, the first insulating member 50 may also be disposed in contact with the electrode assembly 20 to fix and protect the electrode assembly 20.

[0149] In related technologies, the seal 40 and the lower plastic are typically in contact with each other in the area between the end cap and the electrode assembly 20, i.e., within the internal space of the housing 10. However, in this embodiment, as can be seen from the accompanying drawings and the foregoing, since the first sub-part 411 is located inside the electrode lead-out hole 12, the first insulating member 50 and the first sub-part 411 need to be in contact with each other at the opening of the electrode lead-out hole 12 or inside the electrode lead-out hole 12.

[0150] Therefore, in this embodiment, the seal 40 and the first insulating member 50 do not make contact inside the housing 10, but at the opening of the electrode lead-out hole 12 or inside the electrode lead-out hole 12. Thus, the seal 40 does not extend to the side of the wall 11 facing the electrode assembly 20, that is, the presence of the seal 40 does not occupy the internal space of the housing 10, thereby helping to improve the energy density of the battery cell 500.

[0151] In some embodiments, the electrode terminal 30 includes a first terminal portion 31, a second terminal portion 32, and a third terminal portion 33. The first terminal portion 31 is located on the side of the wall portion 11 facing the electrode assembly 20, and the third terminal portion 33 is located on the side of the wall portion 11 away from the electrode assembly 20. A portion of the wall portion 11 is located between the first terminal portion 31 and the third terminal portion 33. The second terminal portion 32 is connected to the first terminal portion 31 and the third terminal portion 33, and the second terminal portion 32 is at least partially accommodated in the electrode lead-out hole 12.

[0152] like Figure 6 As shown, the first insulating member 50 includes a first insulating portion 51 located on the side of the first terminal portion 31 opposite to the electrode assembly 20. The first insulating portion 51 is partially located within the electrode lead-out hole 12 and contacts the first sub-portion 411. Alternatively, please refer to... Figure 8 The electrode lead-out hole 12 includes a first opening 121 facing the electrode assembly 20, and the first insulating part 51 and the first sub-part 411 are in contact at the first opening 121.

[0153] The electrode terminal 30 includes a first terminal portion 31, a second terminal portion 32, and a third terminal portion 33. The two ends of the second terminal portion 32 in the axial direction X are respectively connected to the first terminal portion 31 and the third terminal portion 33. Optionally, the first terminal portion 31, the second terminal portion 32, and the third terminal portion 33 can be an integral structure, and all three include conductive materials such as metal.

[0154] A portion of the second terminal portion 32 is located within the electrode lead-out hole 12, and both ends of the second terminal portion 32 extend beyond the electrode lead-out hole 12 along the axial direction X. The first terminal portion 31 and the third terminal portion 33 are respectively disposed on both sides of the wall portion 11 along the axial direction X, and a portion of the wall portion 11 is located between the first terminal portion 31 and the third terminal portion 33. The phrase "a portion of the wall portion 11 is located between the first terminal portion 31 and the third terminal portion 33" means that in the projection plane perpendicular to the axial direction X, the orthographic projection of the first terminal portion 31 and the orthographic projection of the third terminal portion 33 are both partially located outside the orthographic projection of the electrode lead-out hole 12, and there is an overlapping area with the orthographic projection of the wall portion 11.

[0155] The first terminal portion 31 is located on the side of the wall portion 11 facing the electrode assembly 20, that is, inside the housing 10. The first terminal portion 31 can be directly connected to the electrode tab 21, or it can be electrically connected to the electrode tab 21 through a current collector. The third terminal portion 33 is located on the side of the wall portion 11 away from the electrode assembly 20, that is, outside the housing 10. The third terminal portion 33 can be connected to an external component.

[0156] Along the axial direction X, the first terminal portion 31 and the wall portion 11 are spaced apart. The first insulating portion 51 is at least partially located between the first terminal portion 31 and the wall portion 11, that is, in a projection plane perpendicular to the axial direction X, the orthographic projection of the first insulating portion 51 is located within the orthographic projection of the first terminal portion 31. The first opening 121 is the opening of the electrode lead-out hole 12 facing one end of the electrode assembly 20, wherein the first insulating portion 51 can contact the first sub-portion 411 at the first opening 121, that is, the first insulating portion 51 does not extend into the electrode lead-out hole 12 but contacts the first sub-portion 411 at the opening position of the electrode lead-out hole 12. Alternatively, a portion of the structure in the first insulating portion 51 can also extend into the electrode lead-out hole 12 through the first opening 121 and contact the first sub-portion 411.

[0157] In this embodiment, the seal 40 does not extend into the housing 10, thereby helping to improve the energy density of the battery cell 500. Furthermore, due to the varying radial dimensions of the first seal 40, the end of the first sub-part 411 facing the electrode assembly 20 often has a smaller end face area. Based on this, by changing the size and shape of the first insulating member 50, the first insulating member 50 includes a first insulating portion 51, and contacts the first terminal portion 31 via the first insulating portion 51, instead of directly contacting the first sub-part 411 with the first terminal portion 31. This helps to increase the contact area and improve the contact strength, thereby improving the insulation reliability between the first terminal portion 31 and the wall portion 11.

[0158] In some alternative embodiments, the first insulating member 50 further includes a second insulating portion 52, which is connected to the first insulating portion 51 and located on the outer periphery of the first insulating portion 51. The thickness of the second insulating portion 52 is greater than the thickness of the first insulating portion 51. The second insulating portion 52 is used to achieve electrical insulation between the wall portion 11 and the electrode assembly 20.

[0159] In some embodiments, such as Figure 8 As shown, the first insulating part 51 is in contact with the outer peripheral surface of the second terminal part 32.

[0160] In this embodiment, by contacting the outer peripheral surface of the first insulating portion 51 with the second terminal portion 32, the overlap area between the orthographic projection of the first insulating portion 51 and the orthographic projection of the first terminal portion 31 in the projection plane perpendicular to the axial direction X is increased, thereby further increasing the contact area between the first insulating portion 51 and the first terminal portion 31 and improving the insulation reliability between the wall portion 11 and the first terminal portion 31. Furthermore, by providing the first insulating portion 51 around and in contact with the second terminal portion 32, the insulation reliability between the second terminal portion 32 and the wall portion 11 can be improved by means of the first insulating portion 51.

[0161] In some embodiments, the seal 40 is sandwiched between the third terminal portion 33 and the first insulating member 50. The term "sandwiched" here means that, in the axial direction X, one end of the seal 40 is in close contact with the third terminal portion 33 and the other end is in close contact with the first insulating member 50, that is, the seal 40 is subjected to the joint clamping and compression of the third terminal portion 33 and the first insulating member 50.

[0162] Alternatively, the third terminal portion 33 includes a first portion 331 connected to the second terminal portion 32 and a second portion 332 disposed on the periphery of the first portion 331. The first portion 331 and the second portion 332 are riveted together, and the sealing member 40 is sandwiched between the second portion 332 and the first insulating member 50.

[0163] During the assembly of electrode terminal 30 and wall portion 11, the first portion 331 moves through the electrode lead-out hole 12 to the side of wall portion 11 opposite to electrode assembly 20, and then is fixedly connected to the second portion 332 by riveting. During the riveting process, the second portion 332 comes into contact with and presses against the seal 40, causing the seal 40 to tend to move closer to the electrode assembly 20.

[0164] In this embodiment, the third terminal portion 33 and the first insulating member 50 can jointly compress the sealing member 40 in the axial direction X, causing the sealing member 40 to expand radially, thereby improving the sealing performance. Simultaneously, during the assembly of the electrode terminal 30, due to the riveting process, the sealing member 40 tends to move closer to the electrode assembly 20, thereby increasing the interference between the second sub-part 412 and the hole wall of the electrode lead-out hole 12, thus enhancing the sealing effect.

[0165] In some embodiments, such as Figure 8 As shown, the seal 40 includes a second sealing portion 42, which is connected to the first sealing portion 41 and located on the side of the first sealing portion 41 away from the electrode assembly 20. The radial dimension of the second sealing portion 42 is larger than that of the first sealing portion 41 in the radial direction. In the axial direction X, a portion of the second sealing portion 42 is sandwiched between the wall portion 11 and the electrode terminal 30.

[0166] The term "clamping" as used here refers to the following: in the axial direction X, one end face of the second sealing portion 42 is in close contact with the electrode terminal 30, and the other end face is in close contact with the wall portion 11, meaning that the second sealing portion 42 is clamped and squeezed by both the electrode terminal 30 and the wall portion 11. Further optionally, in the axial direction X, a portion of the second sealing portion 42 is clamped between the wall portion 11 and the third terminal portion 33.

[0167] The second sealing portion 42 may have a shape and size that, exemplarily, is similar to the first sealing portion 41, with at least a portion of the structure in the second sealing portion 42 exhibiting a gradually increasing radial dimension along the direction from the electrode assembly 20 to the wall portion 11. Alternatively, at least a portion of the structure in the second sealing portion 42 may have a consistent radial dimension.

[0168] In some alternative embodiments, the second sealing portion 42 includes a third sub-portion 421 and a fourth sub-portion 422 located on the side of the third sub-portion 421 facing away from the electrode assembly 20. The inclination angle of the outer peripheral surface of the third sub-portion 421 relative to the axial direction X is the same as the inclination angle of the first outer peripheral surface M1 of the first sub-portion 411 relative to the axial direction X. The radial dimension of the fourth sub-portion 422 remains consistent at different locations. In other words, during the design phase of the seal 40, the outer peripheral surfaces of the first sub-portion 411, the second sub-portion 412, and the third sub-portion 421 can be designed coplanarly, while the outer peripheral surface of the fourth sub-portion 422 is designed parallel to the axial direction X.

[0169] The radial dimension of the second sealing part 42 is greater than that of the first sealing part 41. The dimension mentioned here refers to the maximum radial dimension, that is, the maximum radial dimension of the second sealing part 42 is greater than that of the first sealing part 41. The maximum radial dimension of the first sealing part 41 is often consistent with the maximum radial dimension of the electrode lead-out hole 12. Thus, the maximum radial dimension of the second sealing part 42 is greater than that of the electrode lead-out hole 12. Optionally, in the projection plane perpendicular to the axial direction X, the orthographic projection of the second sealing part 42 covers and extends beyond the orthographic projection of the electrode lead-out hole 12.

[0170] In this embodiment, the second sealing portion 42 is a structure located outside the electrode lead-out hole 12 within the sealing member 40. Furthermore, by setting the radial dimension of the second sealing portion 42 to be larger than that of the first sealing portion 41, the second sealing portion 42 will not penetrate into the electrode lead-out hole 12 even under external force, thereby improving the positional reliability of the sealing member 40 relative to the wall portion 11. Additionally, the second sealing portion 42 is subjected to the combined clamping and compression of the electrode terminal 30 and the wall portion 11 in the axial direction X, which further enhances sealing reliability and reduces the risk of external dust and impurities entering the housing 10 and electrolyte transferring to the external environment.

[0171] In some embodiments, the battery cell 500 further includes a second insulating member 60 disposed on the side of the wall portion 11 away from the electrode assembly 20. The second insulating member 60 has a through hole 61 that communicates with the electrode lead-out hole 12. The second sealing portion 42 is located in the through hole 61 and is disposed in contact with the second insulating member 60.

[0172] The second insulating member 60 is used to achieve electrical insulation between the wall portion 11 and the electrode terminal 30. Exemplarily, the first insulating member 50 is an upper plastic, which is pre-molded integrally from plastic or assembled from various plastic components. Further, at least a portion of the second insulating member 60 is sandwiched between the third terminal portion 33 and the wall portion 11 to achieve electrical insulation between the third terminal portion 33 and the wall portion 11.

[0173] In this embodiment, since the end of the sealing member 40 facing away from the electrode assembly 20 has a large end face area, the end of the sealing member 40 facing away from the electrode assembly 20 can be extended beyond the electrode lead-out hole 12 to form a second sealing part 42. The second sealing part 42 and the second insulating member 60 are arranged to contact each other in the radial direction. In this way, the second sealing part 42 and the second insulating member 60 can contact the third terminal part 33 in the axial direction X, thereby improving the insulation effect between the third terminal part 33 and the wall part 11. At the same time, when factors such as riveting process and external force occur, the third terminal part 33 can directly transfer stress to the second sealing part 42 and make the sealing member 40 self-sealing, thereby improving the sealing effect.

[0174] In some embodiments, the material of the seal 40 includes polytetrafluoroethylene (PTFE), perfluoroalkoxy vinyl ether copolymer (PFA), polytrifluorochloroethylene (PCTFE), polyetheretherketone (PEEK), or polyimide (PI).

[0175] In this embodiment, polytetrafluoroethylene, perfluoroalkoxy vinyl ether copolymer, polychlorotrifluoroethylene, polyether ether ketone, and polyimide can all resist the corrosion of electrolyte. By setting the material of the sealing element 40 to one of the above, it is helpful to block water vapor by means of its dense molecular structure and hydrophobicity, reducing the risk of external water vapor entering into the housing 10 and electrolyte penetrating out of the housing 10. At the same time, these materials have a certain structural strength, which can increase the difficulty of deformation of the sealing element 40 and make the sealing element 40 in close contact with the hole wall of the electrode lead-out hole 12 and the electrode terminal 30, thereby improving the sealing effect.

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

[0177] It should be noted that the battery device 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] Thirdly, embodiments of this application provide an electrical device, which includes the battery device in any of the foregoing embodiments.

[0179] According to some embodiments of this application, please refer to Figures 4 to 7 The battery cell 500 includes a housing 10, an electrode assembly 20, electrode terminals 30, a seal 40, a first insulating member 50, and a second insulating member 60. The housing 10 includes a wall portion 11, which has an electrode lead-out hole 12. The electrode assembly 20 is disposed inside the housing 10 and includes a tab 21. The size of the electrode lead-out hole 12 gradually increases in the radial direction away from the electrode assembly 20.

[0180] The electrode terminal 30 includes a first terminal portion 31, a second terminal portion 32, and a third terminal portion 33. The first terminal portion 31 is located on the side of the wall portion 11 facing the electrode assembly 20, and the third terminal portion 33 is located on the side of the wall portion 11 facing away from the electrode assembly 20. A portion of the wall portion 11 is located between the first terminal portion 31 and the third terminal portion 33. The second terminal portion 32 is connected to the first terminal portion 31 and the third terminal portion 33, and at least a portion of the second terminal portion 32 is accommodated in the electrode lead-out hole 12.

[0181] The seal 40 includes a first sealing portion 41 that is received within the electrode lead-out hole 12 and surrounds the electrode terminal 30. At least a portion of the first sealing portion 41 is sandwiched between the electrode terminal 30 and the hole wall of the electrode lead-out hole 12 in the radial direction of the electrode lead-out hole 12. In the direction of the electrode assembly 20 pointing towards the wall portion 11, the size of the first sealing portion 41 in the radial direction of the electrode lead-out hole 12 gradually increases.

[0182] The first sealing portion 41 includes a first sub-portion 411 and a second sub-portion 412 located on the side of the first sub-portion 411 facing away from the electrode assembly 20. The first sub-portion 411 includes a first outer peripheral surface M1, and the second sub-portion 412 includes a second outer peripheral surface M2. The first outer peripheral surface M1 and the hole wall are spaced apart to form a gap space J, and the second outer peripheral surface M2 is in contact with the hole wall. The first insulating member 50 includes a first insulating portion 51 located on the side of the first terminal portion 31 facing away from the electrode assembly 20. The first insulating portion 51 is partially located in the electrode lead-out hole 12 and in contact with the first sub-portion 411. The sealing member 40 is sandwiched between the third terminal portion 33 and the first insulating member 50.

[0183] The seal 40 includes a second sealing portion 42, which is connected to the first sealing portion 41 and located on the side of the first sealing portion 41 away from the electrode assembly 20. The radial dimension of the second sealing portion 42 is larger than that of the first sealing portion 41. In the axial direction X of the electrode lead-out hole 12, a portion of the second sealing portion 42 is sandwiched between the wall portion 11 and the electrode terminal 30. A second insulating member 60 is disposed on the side of the wall portion 11 away from the electrode assembly 20. The second insulating member 60 has a through hole 61 communicating with the electrode lead-out hole 12. The second sealing portion 42 is located within the through hole 61 and is in contact with the second insulating member 60.

[0184] 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 includes a wall portion, wherein the wall portion is provided with electrode lead-out holes; An electrode assembly is disposed within the housing, the electrode assembly including tabs; An electrode terminal is at least partially accommodated in the electrode lead-out hole, and the electrode terminal is electrically connected to the electrode tab; The sealing element includes a first sealing portion housed within the electrode lead-out hole and surrounding the electrode terminal. At least a portion of the first sealing portion is sandwiched between the electrode terminal and the hole wall of the electrode lead-out hole in the radial direction of the electrode lead-out hole. The size of the first sealing portion in the radial direction of the electrode lead-out hole gradually increases in the direction of the electrode assembly pointing towards the wall.

2. The battery cell according to claim 1, characterized in that, The size of the electrode lead-out hole gradually increases in the radial direction away from the electrode assembly.

3. The battery cell according to claim 2, characterized in that, The first sealing portion includes a first sub-part and a second sub-part located on the side of the first sub-part away from the electrode assembly. The first sub-part includes a first outer peripheral surface, and the second sub-part includes a second outer peripheral surface. The first outer peripheral surface and the hole wall are spaced apart to form a gap space, and the second outer peripheral surface is in contact with the hole wall.

4. The battery cell according to claim 3, characterized in that, The first outer peripheral surface is inclined at an angle a1 relative to the axial direction of the electrode lead-out hole, and the hole wall is inclined at an angle a2 relative to the axial direction. Among them, a1 and a2 satisfy: a1 > a2.

5. The battery cell according to claim 4, characterized in that, 3°≤a1-a2≤15°.

6. The battery cell according to claim 3, characterized in that, It also includes a first insulating member, which is at least partially disposed between the wall portion and the electrode assembly and is in contact with the first sub-part.

7. The battery cell according to claim 6, characterized in that, The electrode terminal includes a first terminal portion, a second terminal portion, and a third terminal portion. The first terminal portion is located on the side of the wall portion facing the electrode assembly, and the third terminal portion is located on the side of the wall portion facing away from the electrode assembly. A portion of the wall portion is located between the first terminal portion and the third terminal portion. The second terminal portion is connected to the first terminal portion and the third terminal portion, and at least a portion of the second terminal portion is accommodated in the electrode lead-out hole. Wherein, the first insulating member includes a first insulating portion located on the side of the first terminal portion away from the electrode assembly, the first insulating portion being partially located within the electrode lead-out hole and in contact with the first sub-part; or, the electrode lead-out hole includes a first opening facing the electrode assembly, the first insulating portion and the first sub-part contacting each other at the first opening.

8. The battery cell according to claim 7, characterized in that, The first insulating portion is disposed in contact with the outer peripheral surface of the second terminal portion.

9. The battery cell according to claim 7, characterized in that, The sealing element is sandwiched between the third terminal portion and the first insulating element.

10. The battery cell according to claim 1, characterized in that, The seal includes a second sealing portion connected to the first sealing portion and located on the side of the first sealing portion away from the electrode assembly, and the radial dimension of the second sealing portion is larger than the radial dimension of the first sealing portion. In the axial direction of the electrode lead-out hole, a portion of the second sealing part is sandwiched between the wall portion and the electrode terminal.

11. The battery cell according to claim 10, characterized in that, It also includes a second insulating member disposed on the side of the wall away from the electrode assembly, the second insulating member having a through hole that communicates with the electrode lead-out hole, and the second sealing part being located inside the through hole and in contact with the second insulating member.

12. The battery cell according to claim 1, characterized in that, The sealing element is made of polytetrafluoroethylene, perfluoroalkoxy vinyl ether copolymer, polychlorotrifluoroethylene, polyetheretherketone, or polyimide.

13. A battery device, characterized in that, Includes the battery cell as described in any one of claims 1-12.

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

Images