Battery cell, battery apparatus, and electric apparatus

Abstract

The present application discloses a battery cell, a battery apparatus, and an electric apparatus. The battery cell of embodiments of the present application comprises a casing, an electrode assembly, and connecting structures. An end portion of the casing is provided with an electrode terminal; the electrode assembly is arranged in the casing, and the electrode assembly comprises a main body portion and a tab assembly led out from the main body portion in a first direction; the connecting structures are arranged to connect the tab assembly and the electrode terminal, and each connecting structure comprises a first connecting member and a second connecting member which are connected to each other; the first connecting members extend in the first direction and are connected to the tab assembly, and the second connecting members are connected to the electrode terminal; a space is formed between the casing and the main body portion; and the height of the space in the first direction ranges from 5 mm to 40 mm. The problem of reliability of the battery cell is solved.

Description

Battery cells, battery packs, and electrical devices Technical Field

[0001] This application relates to the field of batteries, 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. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and rechargeable alkaline zinc-manganese battery cells, among others.

[0003] During use, battery cells generate gas, which has a significant impact on the reliability of the battery cells.

[0004] Utility Model Content

[0005] This application provides a battery cell, a battery, and an electrical device that can provide a larger gas storage space for the battery cell and improve the reliability of the battery cell.

[0006] In a first aspect, embodiments of this application provide a battery cell including a casing, an electrode assembly, and a connection structure. The casing includes a first wall with electrode terminals disposed thereon. The electrode assembly is disposed within the casing and includes a main body and a tab assembly extending from the main body along a first direction. The connection structure includes a first connector and a second connector that are interconnected. The first connector extends at least partially along the first direction and is connected to the tab assembly. The second connector is connected to the electrode terminals. A space is formed between the casing and the main body. The height of the space along the first direction ranges from 5 to 40 millimeters.

[0007] The gas generated by the reaction in the main body is discharged along the side where the tab assembly is located in the first direction, and the gas is mainly stored between the main body and the outer casing. A connecting structure is used to connect the tab assembly and the electrode terminals, increasing the gas storage space between the outer casing and the main body while keeping the extension length of the tab assembly constant. A first connector extends at least partially along the first direction, creating a space between the main body and the outer casing, thereby increasing the distance between them. The height of this space along the first direction ranges from 5 to 40 millimeters, increasing the gas capacity within the outer casing, reducing the internal pressure of the outer casing, and improving the lifespan and reliability of the battery cells.

[0008] In some embodiments, the height of the space along the first direction ranges from 8 to 20 millimeters. This increases the gas containment volume while maintaining a high energy density.

[0009] In some embodiments, the first connector includes a first segment and a second segment, the second segment connecting the second connector and the first segment, the first segment connecting to the electrode assembly, and the second segment disposed along a first direction between the electrode assembly and the sidewall of the housing. The second segment, disposed along the first direction, forms a space, providing storage space for gas within the housing, reducing the internal pressure of the housing, and improving the lifespan and reliability of the battery cells. The second segment can better maintain the spacing between the electrode assembly and the sidewall of the housing, preserving the stability of the space.

[0010] In some embodiments, both the tab assembly and the first segment extend along a first direction and overlap and connect along a second direction, with the first and second directions intersecting. The tab assembly extending along the first direction reduces redundancy caused by bending at the root of the connection between the tab assembly and the main body. When the tab assembly extends along the first direction, both the first and second segments extend along the first direction, and the tab assembly overlaps and connects with the first segment, ensuring a stable connection between the first segment and the tab assembly, which is more conducive to gas discharge and expansion of the gas storage volume. When the first segment extends along the first direction, the tab assembly does not need to be bent, reducing manufacturing steps and facilitating welding.

[0011] In some embodiments, the first segment and the second segment are angled together. The end of the tab assembly facing away from the main body extends along a second direction and overlaps with the first segment along a first direction, with the first and second directions intersecting. This facilitates the overlapping connection between the first segment and the bent tab assembly, improving the stability of the connection between the first segment and the tab assembly, and allowing the second segment to be more firmly supported between the housing and the main body. When the first segment is bent, the tab assembly and the connecting structure are prone to vertical deformation, which can reduce the pulling force on the tab assembly under vibration conditions and prevent the tab assembly from tearing.

[0012] In some embodiments, the tab assembly is at least partially connected to the side of the first segment opposite to the main body along a first direction. When the battery cell is subjected to an opposite pulling force along the first direction, the tab assembly and the adapter form a relative force that causes them to adhere to each other, thereby improving the connection strength between the tab assembly and the adapter.

[0013] In some embodiments, along the width direction of the battery cell, the first segment faces inward relative to the second segment. The inward bending of the first segment saves volume in the thickness direction of the battery cell, making it more suitable for thinner battery cells.

[0014] In some embodiments, along the width direction of the battery cell, the first segment faces outward relative to the second segment. The outward bending of the first segment facilitates the welding operation.

[0015] In some embodiments, the second connector extends along a second direction and is connected to the second segment by welding or bonding. The first connector and the second connector are separate structures, connected by welding or bonding, which facilitates maintenance and modification of existing structures and reduces manufacturing difficulty.

[0016] In some embodiments, the first connector and the second connector are integrally formed structures. This integral forming structure improves the overall structure's load-bearing capacity, provides better stability in oscillating environments, and simplifies installation.

[0017] In some embodiments, the housing includes a casing and an end cap. The casing has an opening at at least one end along a first direction, and the end cap closes the opening. An electrode assembly is at least partially housed within the casing, and electrode terminals are disposed on the end cap. A space is formed between one of the end cap and the casing and the electrode assembly. This space, formed between the end cap and the casing and the electrode assembly, provides space for areas prone to pressure deformation, improving the stability of the battery cell. It also reduces the gas flow path, thereby lowering the risk of multi-regional pressure deformation of the casing.

[0018] In some embodiments, the electrode assembly includes a first electrode and a second electrode with opposite polarities. The first electrode and the second electrode are led out from at least one side of the main body along a first direction. The first electrode and the second electrode are respectively connected to corresponding posts in the electrode terminals via a connecting structure. A space is formed between the end cap and the first electrode and the second electrode. The connection between the end cap and the housing is weaker than other locations. Providing a space between the end cap and the first electrode and the second electrode reduces the risk of deformation or even cracking due to internal pressure between the end cap and the housing. Furthermore, when the internal pressure is too high, gas can easily escape from the explosion-proof device of the end cap.

[0019] In some embodiments, the first electrode and the second electrode are extended from one side of the main body along a first direction, and the end cap forms a communicating space with the first electrode and the second electrode, respectively. Placing the first electrode and the second electrode on one side can increase the length of the space in the direction in which the first electrode and the second electrode are arranged, thereby increasing the gas storage space.

[0020] In some embodiments, the first electrode and the second electrode are extended from both sides of the main body along a first direction, and the end caps form opposing spaces with the first electrode and the second electrode along the first direction. The first electrode and the second electrode are placed on both sides, forming opposing spaces, which facilitates gas dispersion and avoids excessive internal pressure.

[0021] In some embodiments, the electrode assembly includes a first electrode and a second electrode with opposite polarities. The first electrode and the second electrode are extended from both sides of the main body along a first direction, and are respectively connected to corresponding posts in the electrode terminals via a connecting structure. A space is formed between the housing and the first electrode and the second electrode, respectively, along the first direction. The housing has a relatively thin wall thickness. To reduce the deformation of the housing caused by excessive pressure at the gas-generating end of the main body, spaces are provided between the first electrode and the second electrode and the opposite sidewalls of the housing to facilitate gas dispersion and prevent excessive internal pressure.

[0022] Secondly, embodiments of this application also provide a battery device, including the battery cell provided in any of the embodiments of the first aspect.

[0023] Thirdly, embodiments of this application also provide an electrical device configured to receive electrical energy from a battery device according to any embodiment of the second aspect. Attached Figure Description

[0024] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0025] Figure 1 is a structural schematic diagram of a vehicle provided in some embodiments of this application;

[0026] Figure 2 is a schematic diagram of a battery device provided in some embodiments of this application;

[0027] Figure 3 is a schematic diagram of a first example of a battery cell provided in some embodiments of this application;

[0028] Figure 4 is a schematic diagram of the connection state between the electrode assembly and the end cap provided in some embodiments of this application;

[0029] Figure 5 is an unfolded view of an example of an electrode assembly provided in some embodiments of this application;

[0030] Figure 6 is an expanded view of another example of the electrode assembly provided in some embodiments of this application;

[0031] Figure 7 is a partial left view of the first example in Figure 3;

[0032] Figure 8 is a partial left view of the second example in Figure 3;

[0033] Figure 9 is a partial left view of the third example in Figure 3;

[0034] Figure 10 is a partial left view of the fourth example in Figure 3;

[0035] Figure 11 is a partial left view of the fifth example in Figure 3;

[0036] Figure 12 is a partial left view of the sixth example in Figure 3;

[0037] Figure 13 is a schematic diagram of a second example of a battery cell provided in some embodiments of this application;

[0038] Figure 14 is a schematic diagram of a third example of a battery cell provided in some embodiments of this application.

[0039] The accompanying drawings are not necessarily drawn to scale.

[0040] Explanation of reference numerals in the attached drawings: 1. Vehicle; 10. Electrode assembly; 11. Main body; 12. Tab assembly; 121. First tab; 122. Second tab; 2. Battery assembly; 20. Housing; 21. Shell; 22. End cap; 221. Cover plate; 222. Lower plastic; 223. First end cap; 224. Second end cap; 23. Electrode terminal; 231. First electrode terminal; 232. Second electrode terminal; 3. Controller; 30. Connection structure; 31. First connector; 311. Second section; 312. First section; 32. Second connector; 4. Motor; 40. Space; 5. Housing; 5a. First housing; 5b. Second housing; 6. Battery module; 7. Battery cell; X, Second direction; Y, Third direction; Z, First direction. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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).

[0047] 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.

[0048] 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.

[0049] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0050] A battery device typically refers to a single physical module comprising multiple battery cells to provide higher voltage and capacity. A battery cell can be the smallest unit that makes up a battery device.

[0051] A battery cell typically includes a casing, an electrode assembly housed within the casing, and electrode terminals disposed on the casing; the electrode terminals include a first electrode terminal and a second electrode terminal. The electrode assembly typically includes a positive tab and a negative tab, with the first electrode terminal electrically connected to the positive tab and the second electrode terminal electrically connected to the negative tab. The first electrode terminal and the negative second electrode terminal are used for electrical connection to an external circuit to enable charging or discharging of the battery cell.

[0052] During the use of a battery cell, the electrode assembly generates gas, which is mainly stored in the limited space between the electrode assembly and the casing. For electrode assemblies with a large gas production, an insufficient space between the electrode assembly and the casing leads to increased internal pressure within the battery cell. Excessive local pressure can easily cause deformation of the casing, affecting the stability of the battery cell. Furthermore, to consider the manufacturability and stability of the electrode assembly, the impact on the size of the electrode assembly should be minimized.

[0053] In view of this, the present application provides a battery cell that, by setting a connection structure between the electrode assembly and the electrode terminal, increases the distance between the electrode assembly and the outer casing along the lead-out direction of the electrode assembly through the connection structure, thereby forming a space and increasing the gas storage space between the outer casing and the electrode assembly. This can reduce the internal pressure of the battery cell with a large gas production, reduce the probability of outer casing deformation, and improve the stability of the battery cell.

[0054] The battery cells described in this application are applicable to battery devices and electrical devices that use battery devices. Electrical devices can be devices that use battery devices as a power source or various energy storage systems that use battery devices as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0055] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0056] Figure 1 is a schematic diagram of the structure of a vehicle provided in some embodiments of this application.

[0057] As shown in Figure 1, a battery device 2 is installed inside the vehicle 1. The battery device 2 can be located at the bottom, front, or rear of the vehicle 1. The battery device 2 can be used to power the vehicle 1; for example, the battery device 2 can serve as the operating power source for the vehicle 1.

[0058] The vehicle 1 may also include a controller 3 and a motor 4. The controller 3 is used to control the battery device 2 to supply power to the motor 4, for example, for the power needs of the vehicle 1 during starting, navigation and driving.

[0059] In some embodiments of this application, the battery device 2 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0060] Figure 2 is a schematic diagram of a battery device provided in some embodiments of this application.

[0061] In some embodiments, the battery device 2 may include one or more battery cells 7 for providing voltage and capacity.

[0062] The battery cell assembly 7 may include multiple battery cells 7 (not shown in Figure 2), which are connected in series, parallel, or mixed connection via a busbar. Mixed connection means that multiple battery cells 7 are connected in both series and parallel.

[0063] The battery cell 7 can be a secondary battery cell 7, which refers to a battery cell 7 that can be used again after being discharged by recharging to activate the active materials.

[0064] As an example, the battery cell 7 can be a lithium-ion battery cell 7, a sodium-ion battery cell 7, a sodium-lithium-ion battery cell 7, a lithium metal battery cell 7, a sodium metal battery cell 7, a lithium-sulfur battery cell 7, a magnesium-ion battery cell 7, a nickel-metal hydride battery cell 7, a nickel-cadmium battery cell 7, a lead-acid battery cell 7, etc.

[0065] As an example, the battery cell 7 can be a prismatic battery cell 7 or other shapes of battery cell 7. Prismatic battery cells 7 include square battery cells 7, blade-shaped battery cells 7, and multi-prismatic battery cells 7. For example, a hexagonal prismatic battery cell 7 is a multi-prismatic battery cell 7.

[0066] In some embodiments, the battery cell 7 assembly is typically formed by arranging multiple battery cells 7; as an example, the battery cell 7 assembly can be a battery module 6, which is formed by arranging and fixing multiple battery cells 7 into a single module. As an example, the battery module 6 can be formed by bundling multiple battery cells 7 together with cable ties.

[0067] In some embodiments, the battery device 2 may be a battery pack, which includes a housing 5 and one or more battery cell 7 assemblies housed within the housing 5. As an example, the battery cell 7 assembly may be a battery module 6, which can be housed within the housing 5 by fixing the battery module 6 to the housing 5. Alternatively, as an example, the battery cell 7 assembly may be housed within the housing 5 by directly fixing multiple battery cells 7 to the housing 5.

[0068] In some embodiments, the housing 5 is used to house the battery cell 7, and the housing 5 can have various structures.

[0069] In some embodiments, the housing 5 may include a first housing 5a and a second housing 5b. The first housing 5a and the second housing 5b are fastened together to form a closed space inside the housing 5 to house the battery cell 7 assembly. Here, "closed" refers to covering or closing, and can be either sealed or unsealed. The first housing 5a may be a top cover or a bottom plate.

[0070] In some embodiments, the housing 5 may include a top cover, a frame, and a bottom plate. The top cover and the bottom plate are respectively connected to the frame, so that the interior of the housing 5 forms an enclosed space to accommodate the battery cell 7 assembly. As an example, the frame may include multiple side beams.

[0071] In some embodiments, the housing 5 may be part of the chassis structure of the vehicle 1. For example, a portion of the housing 5 may be at least a portion of the floor of the vehicle 1, or a portion of the housing 5 may be at least a portion of the crossbeams and longitudinal beams of the vehicle 1.

[0072] In some embodiments, the battery device 2 may be an energy storage device.

[0073] Energy storage devices can be used in energy storage power stations, wind power generation systems, solar power generation systems, mobile power systems, or temporary power supply systems. Energy storage devices can store electrical energy as needed and output it when appropriate. For example, energy storage devices can store electrical energy during off-peak hours and provide power to relevant users or electrical equipment during peak hours.

[0074] In some embodiments, the energy storage device includes an energy storage container, an energy storage cabinet, etc.

[0075] Figure 3 is a schematic diagram of a first example of a battery cell provided in some embodiments of this application.

[0076] This application provides a battery cell 7, which includes a housing 20 and an electrode assembly 10 housed within the housing 20.

[0077] In some embodiments, the outer casing 20 may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing 20), etc.

[0078] The outer shell 20 may be a hollow structure, with an internal cavity for accommodating the electrode assembly 10 and the electrolyte.

[0079] In some embodiments, the outer casing 20 of the battery cell 7 is a cylindrical casing 20, a square casing 20, a prismatic casing 20, or a casing 20 of other shapes.

[0080] In some embodiments, the housing 20 includes a housing 21 and an end cap 22, the housing 21 having an opening, and the end cap 22 being connected to the housing 21 and covering the opening; the first wall of the housing 20 may be a wall portion of the housing 21 or an end cap.

[0081] The housing 21 is a component used to fit the end cap 22 to form the internal cavity of the battery cell 7. The formed internal cavity can be used to accommodate the electrode assembly 10, the electrolyte, and other components.

[0082] The housing 21 and the end cap 22 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for the battery cell 7.

[0083] The housing 21 can be of various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 10. The housing 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0084] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap 22 is not easily deformed when subjected to compression and impact, so that the battery cell 7 can have higher structural strength and improve reliability.

[0085] The end cap 22 is connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0086] The housing 21 may be open at one end or open at both ends. In some examples, the housing 21 may be a structure with an opening on one side, and one end cap 22 is provided to cover the housing 21. In other examples, the housing 21 may also be a structure with openings on both sides, and two end caps 22 are provided, with the two end caps 22 respectively covering the two openings of the housing 21.

[0087] Electrode assembly 10 is a component in the battery cell 7 where electrochemical reactions occur. The housing 21 may contain one or more electrode assemblies 10.

[0088] In some embodiments, the electrode assembly 10 includes a positive electrode, a negative electrode, and a separator, wherein the positive electrode and the negative electrode have opposite polarities, and the separator separates the positive electrode and the negative electrode.

[0089] At least a portion of the separator is located between the positive and negative electrode plates. During the charging and discharging process of the battery cell 7, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrode plates. The separator, positioned between the positive and negative electrode plates, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0090] In some embodiments, the separator includes a separator membrane. The separator membrane in this application can be any known porous membrane with good chemical and mechanical stability.

[0091] As an example, the main material of the separator can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics. The separator can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator is a multi-layer composite film, the materials of each layer can be the same or different.

[0092] Inorganic particle coating, organic particle coating, or organic / inorganic composite coating can also be applied to the surface of the separator.

[0093] The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surface of the positive or negative electrode.

[0094] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrode plates, serving both to transport ions and to isolate the positive and negative electrodes.

[0095] In some embodiments, the battery cell 7 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte used in this application can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0096] In some embodiments, the liquid electrolyte includes an electrolyte salt and a solvent.

[0097] 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.

[0098] 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 performance of the battery cell 7, such as additives that improve the overcharge / fast charge performance of the battery cell 7, additives that improve the high-temperature performance of the battery cell 7, and additives that improve the low-temperature performance of the battery cell 7.

[0099] In some embodiments, the electrode assembly 10 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0100] In some embodiments, the electrode assembly 10 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0101] In some embodiments, the electrode assembly 10 has a stacked structure.

[0102] As an example, multiple positive and negative electrode plates can be set, with multiple positive and multiple negative electrode plates stacked alternately. As an example, multiple positive electrode plates can be set, and negative electrode plates are folded to form multiple stacked folded segments, with a positive electrode plate sandwiched between adjacent folded segments.

[0103] As an example, both the positive and negative electrode plates are folded to form multiple stacked folded segments.

[0104] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0105] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0106] In some embodiments, the electrode assembly 10 may be cylindrical, flat, or polygonal in shape.

[0107] In some embodiments, the electrode assembly 10 includes a main body 11 and a tab assembly 12 extending from the main body 11. The tab assembly 12 includes a first tab 121 and a second tab 122. One of the first tab 121 and the second tab 122 is a positive tab, and the other is a negative tab.

[0108] The first tab 121 and the second tab 122 can be drawn from the same end of the main body 11, or they can be drawn from opposite ends of the main body 11. That is, the tab assembly 12 is a partial extension of the main body 11.

[0109] In some embodiments, the electrode assembly 10 is a wound structure. The positive electrode tab has a multi-layered structure stacked along the winding axis of the electrode assembly 10. Optionally, the positive electrode tab is cylindrical.

[0110] Figure 4 is a schematic diagram of the connection state between the electrode assembly and the end cap provided in some embodiments of this application; Figure 5 is an unfolded view of an example of the electrode assembly provided in some embodiments of this application; Figure 6 is an unfolded view of another example of the electrode assembly provided in some embodiments of this application.

[0111] As shown in Figures 3 to 6, an embodiment of this application provides a battery cell 7 including a housing 20, an electrode assembly 10, and a connection structure 30. The housing 20 includes a first wall, on which electrode terminals 23 are disposed. The electrode assembly 10 is disposed inside the housing 20 and includes a main body 11 and a tab assembly 12 extending from the main body 11 along a first direction Z. The connection structure 30 includes a first connector 31 and a second connector 32 that are interconnected. The first connector 31 extends at least partially along the first direction Z and is connected to the tab assembly 12. The second connector 32 is connected to the electrode terminals 23. A space 40 is formed between the housing 20 and the main body 11. The height of the space 40 along the first direction Z ranges from 5 to 40 millimeters.

[0112] The connection structure 30 is an electrical connector between the tab assembly 12 and the electrode terminal 23. Exemplarily, the tab assembly 12 includes a first tab 121 and a second tab 122, and the electrode terminal 23 includes a first electrode terminal 231 and a second electrode terminal 232.

[0113] For example, the battery cell 7 includes at least two connection structures 30, one connection structure 30 is connected between the first tab 121 and the first electrode terminal 231, and the other combination connector is connected between the second tab 122 and the second electrode terminal 232.

[0114] The connecting structure 30 includes a first connector 31 and a second connector 32, which can be integrally formed parts or separate assemblies. For example, the first connector 31 and the second connector 32 can be connected together by a welding process.

[0115] The first connector 31 is a structural component with conductive properties. The first connector 31 is connected to one of the tabs in the tab assembly 12. The first connector 31 can be made of a material with good conductivity, such as metal or composite material, for example, copper, aluminum, nickel, stainless steel, etc. The material of the first connector 31 can be the same as or different from the material of the tab of the tab assembly 12. The first connector 31 can be connected to the tab assembly 12 by welding, pressing, crimping, riveting, etc. For example, laser welding or ultrasonic welding. Exemplarily, the first connector 31 can be sheet-like, for example, a rectangular sheet, a circular sheet, a trapezoidal sheet, or other regular or irregular shapes.

[0116] In one example, the thickness of the first connector 31 may be the same as or different from the thickness of the tab of the tab assembly 12, and the thickness of the first connector 31 may be uniform or non-uniform.

[0117] The first connector 31 extends at least partially along the first direction Z. In the example, taking the wound electrode assembly 10 as an example, the lead-out side of the tab assembly 12 is the main gas exhaust side. The extension of the first connector 31 on the main gas exhaust side forms a space 40, which increases the gas storage chamber inside the housing 20, reduces the risk of excessive local pressure, and helps to reduce the internal pressure of the battery cell 7.

[0118] For example, the first connector 31 may extend entirely along the first direction Z, or the portion of the first connector 31 that connects to the tab assembly 12 may extend in another direction. Exemplarily, the first connector 31 may have a bend. Other portions of the first connector 31 may extend along the first direction Z to form a gap between the tab assembly 12 and the second connector 32 in the first direction Z.

[0119] The second connector 32 is a structural component with conductive properties. The second connector 32 is connected to one of the terminals of the electrode terminals 23. The second connector 32 can be made of a material with good conductivity, such as metal or composite material, for example, copper, aluminum, nickel, or stainless steel. The material of the second connector 32 can be the same as or different from the material of the first connector 31. The second connector 32 can be connected to the electrode terminal 23 by welding, pressing, crimping, or other methods. For example, laser welding or ultrasonic welding. The second connector 32 can be sheet-like, for example, a U-shaped sheet, a rectangular sheet, a circular sheet, a trapezoidal sheet, or other regular or irregular shapes. Exemplarily, the thickness of the second connector sheet can be the same as or different from the thickness of the first connector sheet, and the thickness of the second connector 32 can be uniform or non-uniform.

[0120] The second connector 32 may extend integrally along the first direction Z, or the second connector 32 may be intersected with the first connector 31. The second connector 32 may have one or more segments.

[0121] Space 40 is a partial accommodating area for the gas generated by the storage electrode assembly 10, and is connected to other areas within the housing 20. Space 40 may be a corresponding chamber within the housing 20 formed by the portion of the first connector 31 extending along the first direction Z. Space 40 increases the gas storage volume within the housing 20.

[0122] The first direction Z can be the height direction or the length direction of the battery cell 7.

[0123] The height of space 40 along the first direction Z can be 5 mm, 8 mm, 12 mm, 16 mm, 20 mm, 30 mm, 35 mm, or 40 mm.

[0124] The gas generated by the reaction in the main body 11 is discharged along the side where the tab assembly 12 is located in the first direction Z, and the gas is mainly stored between the main body 11 and the outer casing 20. A connecting structure 30 connects the tab assembly 12 and the electrode terminal 23, increasing the connection height between the outer casing 20 and the electrode assembly 10 while keeping the extension length of the tab assembly 12 constant, thus raising the gas storage chamber between the outer casing 20 and the main body 11. A first connector 31 extends at least partially along the first direction Z, forming a space 40 between the main body 11 and the outer casing 20, thereby increasing the distance between them. The height of the space 40 along the first direction Z ranges from 5 to 40 millimeters, increasing the gas capacity within the outer casing 20, reducing the internal pressure of the outer casing 20, and improving the lifespan and reliability of the battery cell 7.

[0125] In an alternative embodiment, the housing 20 includes a housing 21 and an end cap 22, and the space 40 may be located between the end cap 22 and the electrode assembly 10, or the space 40 may be located between the side wall of the housing 21 and the electrode assembly 10.

[0126] In an optional embodiment, the space 40 can be located on one or both sides of the main body 11. For example, the housing 20 has two oppositely disposed end caps 22, and the spaces 40 are respectively formed between the end caps 22 and the electrode assembly 10. The two spaces 40 are respectively located on both sides of the main body 11. The heights of the two spaces 40 along the first direction Z can be the same or different.

[0127] In some embodiments, the height of space 40 along the first direction Z ranges from 8 to 20 millimeters. For example, the height of space 40 along the first direction Z is 9 millimeters, 10 millimeters, 15 millimeters, 18 millimeters, or 19 millimeters.

[0128] While increasing the gas holding volume, a high energy density is maintained.

[0129] As shown in Figure 5, in some embodiments of this application, the first connector 31 and the second connector 32 are connected by welding or bonding.

[0130] The number of first connectors 31 can be one or more, and the number of second connectors 32 can be one or more.

[0131] In one example, the first connector 31 and the second connector 32 are connected by welding methods such as fusion welding, pressure welding, and brazing. For example, fusion welding can be gas welding, laser welding, electron beam welding, etc. In another example, the first connector 31 and the second connector 32 are bonded by a metal adhesive, such as epoxy resin adhesive with added metal powder, metal adhesive, etc.

[0132] Exemplarily, the electrode assembly 10 includes two sets of first tabs 121 and two sets of second tabs 122. The two sets of first tabs 121 are arranged opposite to each other and connected to a post of the electrode terminal 23 via a connecting structure 30. The two sets of second tabs 122 are arranged opposite to each other and connected to another post of the electrode terminal 23 via another connecting structure 30. Taking the connection relationship of the two sets of first tabs 121 as an example, the connecting structure 30 includes a U-shaped second connector 32 and two first connectors 31. The first connectors 31 are respectively connected between the first tabs 121 and the second connectors 32. There is an overlap between the first connectors 31 and the second connectors 32 and the first tabs 121. The first connectors 31 and the second connectors 32 are ultrasonically welded, and the first connecting piece is laser welded to the first tabs 121. There is a gap between the first tabs 121 and the second connectors 32, which is less than 15 mm.

[0133] The first connector 31 and the second connector 32 are separate structures, connected by welding or bonding, which facilitates maintenance and modification and reduces manufacturing difficulty.

[0134] In one embodiment of this application, the first connector 31 is connected to one of the U-shaped sidewalls of the second connector 32. A fusible portion is provided between the U-shaped sidewalls of the second connector 32 for overcurrent protection of the battery cell 7. The fusible portion can be a thinned area or a fusible hole.

[0135] As shown in Figure 6, in some embodiments of this application, the first connector 31 and the second connector 32 are integrally formed structures.

[0136] The first connector 31 and the second connector 32 can be integrally formed through processes such as casting, forging, pressure processing, and 3D printing. For example, processes such as stamping, die forging, and die casting.

[0137] For example, the connection structure 30 includes a U-shaped second connector 32 and two first connectors 31, with the first connectors 31 connected to one of the U-shaped sidewalls of the second connector 32. A fusible portion is provided between the U-shaped sidewalls of the second connector 32 for overcurrent protection of the battery cell 7. The fusible portion can be a thinned area or a fusible hole.

[0138] The first connector 31 and the second connector 32 are integrally formed, which improves the load-bearing capacity of the overall structure, provides better stability in oscillating environments, and simplifies installation.

[0139] Figure 7 is a partial left view of the first example in Figure 3; Figure 8 is a partial left view of the second example in Figure 3; Figure 9 is a partial left view of the third example in Figure 3; and Figure 10 is a partial left view of the fourth example in Figure 3.

[0140] As shown in Figures 7 to 10, in some embodiments of this application, the first connector 31 includes a first segment 312 and a second segment 311. The second segment 311 connects the second connector 32 and the first segment 312. The first segment 312 is connected to the tab assembly 12. The second segment 311 is disposed between the tab assembly 12 and the side wall of the housing 20 along the first direction Z.

[0141] The first segment 312 is a portion of the first connector 31 along its length. The material properties of the first segment 312 are consistent with those of the first connector 31. The first segment 312 is connected to the tab assembly 12. In one example, the first segment 312 extends along a first direction Z, the tab of the tab assembly 12 extends along the first direction Z, the first segment 312 and the tab of the tab assembly 12 overlap along a second direction X, and are welded together. In another example, the first segment 312 extends along a second direction X, the tab of the tab assembly 12 extends along the second direction X, the first segment 312 and the tab of the tab assembly 12 overlap along the first direction Z, and are welded together. The second direction X is perpendicular to the first direction Z; for example, when the first direction Z is the height direction of the battery cell 7, the second direction X is the width direction of the battery cell 7.

[0142] The second segment 311 is another portion of the first connector 31 along its length. The material properties of the first segment 312 are consistent with those of the first connector 31. One end of the second segment 311 is connected to the second connector 32, and the other end is connected to the first segment 312. The second segment 311 and the tab assembly 12 do not overlap in the first direction Z. The second segment 311 is disposed between the tab assembly 12 and the side wall of the housing 20 along the first direction Z, and the height of the second segment 311 along the first direction Z is the height of the space 40 along the first direction Z.

[0143] The second segment 311 is disposed between the tab assembly 12 and the side wall of the housing 20 along the first direction Z. The side wall of the housing 20 can be the end cap 22 or the side wall of the housing 21. In one example, the second segment 311 is disposed between the tab assembly 12 and the end cap 22. The housing 20 includes two end caps 22 disposed opposite to the housing 21, and the second segment 311 is disposed on opposite sides of the housing 21.

[0144] The height of the second segment 311 along the first direction Z can be determined based on the gas production and ampere-hour rating of the battery cell 7. For example, the height of the second segment 311 along the first direction Z is less than 15 mm.

[0145] The space 40 formed by the second segment 311 along the first direction Z serves as a storage chamber for gas within the housing 20, reducing the internal pressure of the housing 20 and improving the lifespan and reliability of the battery cell 7. The second segment 311 also better maintains the spacing between the tab assembly 12 and the sidewall of the housing 20, ensuring the stability of the space 40.

[0146] As shown in Figures 3, 7 and 8, in some embodiments of this application, the tab assembly 12 and the first segment 312 both extend along the first direction Z and overlap and connect along the second direction X.

[0147] Along the first direction Z, the first segment 312 may partially or completely overlap with the tab assembly 12. Along the third direction Y, the first segment 312 may be located in the middle of the tab of the tab assembly 12, or the first segment 312 may be the same width as the tab of the tab assembly 12. The third direction Y is perpendicular to both the second direction X and the first direction Z. For example, the first direction Z is the height direction of the battery cell 7, the second direction X is the width direction of the battery cell 7, and the third direction Y is the length direction of the battery cell 7.

[0148] For example, along the second direction X, the tabs of the tab assembly 12 have opposing first and second connecting surfaces, and the first segment 312 can be connected to the first connecting surface or to the second connecting surface.

[0149] In addition, the electrode assembly 12 includes a first electrode 121 and a second electrode 122, and the first segment 312 of the first connector 31, which is respectively connected to the first electrode 121 and the second electrode 122, can be placed on the same side or different sides.

[0150] The second connector 32 can extend along the first direction Z or along the second direction X. For example, when the second connector 32 extends along the first direction Z, the electrode terminal 23 also extends along the first direction Z, and the second connector 32 and the electrode terminal 23 are connected in an overlapping manner along the second direction X. Alternatively, when the second connector 32 and the electrode terminal 23 both extend along the second direction X, the second connector 32 and the electrode terminal 23 are connected in an overlapping manner along the first direction Z.

[0151] The tab assembly 12 extends along the first direction Z, reducing redundancy caused by bending at the root of the connection between the tab assembly 12 and the main body 11. When the tab assembly 12 extends along the first direction Z, both the first segment 312 and the second segment 311 extend along the first direction Z, and the tab assembly 12 overlaps with the first segment 312, ensuring a stable connection between the first segment 312 and the tab assembly 12, which is more conducive to gas discharge and expansion of the gas storage volume. When the first segment 312 extends along the first direction Z, the tab assembly 12 does not need to be bent, reducing manufacturing steps and facilitating welding.

[0152] As shown in Figures 9 and 10, in some embodiments of this application, the first segment 312 and the second segment 311 are set at an angle, the end of the tab assembly 12 away from the main body 11 extends along the second direction X and overlaps and connects with the first segment 312 along the first direction Z, and the first direction Z intersects the second direction X.

[0153] For example, the angle between the first segment 312 and the second segment 311 opens toward the second segment 311 on the opposite side. For example, the angle ranges from 60 degrees to 150 degrees.

[0154] For example, the first segment 312 is positioned along the second direction X and is perpendicular to the second segment 311 positioned along the first direction Z.

[0155] In some examples, the tabs of the tab assembly 12 extend along the second direction X, and the first segment 312 extends along the second direction X. The first segment 312 is stacked and connected to the tab assembly 12 along the first direction Z. The first segment 312 may be parallel or perpendicular to the second connector 32.

[0156] In one example, the second connector 32 may extend along a first direction Z or a second direction X. For instance, when the second connector 32 extends along the first direction Z, the electrode terminal 23 also extends along the first direction Z, and the second connector 32 and the electrode terminal 23 are connected in an overlapping manner along the second direction X. As another example, when the second connector 32 extends along the second direction X, the electrode terminal 23 also extends along the second direction X, and the second connector 32 and the electrode terminal 23 are connected in an overlapping manner along the first direction Z.

[0157] This arrangement facilitates the overlapping connection between the first segment 312 and the bent tab assembly 12, improving the stability of the connection between the first segment 312 and the tab assembly 12, and also allows the second segment 311 to be stably supported between the housing 21 and the main body 11. When the first segment 312 is in a bent state, the tab assembly 12 and the connecting structure 30 are prone to vertical deformation, which can reduce the pulling force on the tab assembly 12 under vibration conditions and prevent the tab assembly 12 from tearing.

[0158] Figure 11 is a partial left view of the fifth example in Figure 3.

[0159] As shown in FIG11, in some embodiments, the tab assembly 12 is at least partially connected along the first direction Z to the side of the first segment 312 facing away from the main body 11.

[0160] Exemplarily, the tab assembly 12 extends at least partially along a first direction Z and is connected to a first segment 312 of the first connector 31. The first segment 312 of the first connector 31 is connected at an angle to a second segment 311. The first segment 312 extends along a second direction X and a first direction Z, and is closer to the tab assembly 12 relative to the second segment 311. The tab assembly 12 is at least partially positioned above the first segment 312.

[0161] When the battery cell 7 is subjected to opposite tension along the first direction Z, the tab assembly 12 and the first connector 31 tend to move in opposite directions, and the tab assembly 12 and the adapter form a relative force that makes them fit together, thereby improving the connection strength between the tab assembly 12 and the adapter.

[0162] As shown in Figure 10, in some embodiments, along the width direction of the battery cell 7, the first segment 312 faces the interior of the battery cell 7 relative to the second segment 311.

[0163] The width direction of the battery cell 7 can be the second direction X.

[0164] For example, the first segment 312 of the first connector 31 is connected to the second segment 311 at an angle. The first segment 312 extends along the second direction X, and the second segment 311 extends along the first direction Z. The end of the first segment 312 is away from the second segment 311 and faces the interior of the battery cell 7.

[0165] The interior and exterior of the battery cell 7 are defined by the housing 20. The interior is the chamber within the housing 20 used to house the electrode assembly 10, and the area outside the housing 20 is the exterior. Exemplarily, the first segment 312 and the second segment 311 may be perpendicular.

[0166] The inward bending of the first section 312 can save volume in the thickness direction of the battery cell 7, making it more suitable for thin battery cells 7.

[0167] As shown in Figure 11, in some embodiments, along the width direction of the battery cell 7, the first segment 312 faces outward relative to the second segment 311 of the battery cell 7.

[0168] For example, the first segment 312 of the first connector 31 is connected to the second segment 311 at an angle. The second segment 311 extends along the first direction Z, and the first segment 312 extends along the second direction X. The end of the first segment 312 is away from the second segment 311 and faces the housing 20.

[0169] In one example, the first segment 312 and the second segment 311 are placed inside the housing 20, and the end of the first segment 312 points towards the housing 20.

[0170] The first section 312 bends outward to facilitate welding operations.

[0171] Figure 12 is a partial left view of the sixth example in Figure 3.

[0172] As shown in Figures 5 and 12, in some embodiments, the second connector 32 extends along the second direction X, and the second connector 32 is connected to the second segment 311 by welding or bonding.

[0173] For example, the first segment 312 of the first connector 31 is connected to the second segment 311 at an angle, the first segment 312 extends at least partially along the first direction Z, and the second segment 311 extends along the second direction X. The second connector 32 is connected to the second segment 311 in an overlapping manner along the first direction Z.

[0174] In one example, the second segment 311 is positioned above the second connector 32, and at least a portion of the first segment 312 is connected to the tab assembly 12.

[0175] It facilitates modification on existing structures and reduces manufacturing difficulty.

[0176] In some embodiments of this application, the length of the second segment 311 along the first direction Z is less than or equal to 15 millimeters.

[0177] The height increase between the sidewall of the outer casing 20 and the main body 11 of the electrode assembly 10 can take into account the relationship between the gas production of the electrode assembly 10 and the battery capacity. With the gas production of the electrode assembly 10 confirmed, the length of the second segment 311 along the first direction Z is determined by expressing the battery capacity in ampere-hours.

[0178] For example, if the ampere-hour count is less than or equal to 50, the length of the second segment 311 is less than or equal to 6 millimeters. If the ampere-hour count ranges from 50 to 150 (inclusive), the length of the second segment 311 is 6 millimeters to 12 millimeters (inclusive). If the ampere-hour count ranges from 150 to 300 (inclusive), the length of the second segment 311 is 12 millimeters to 15 millimeters (inclusive).

[0179] When a space 40 is formed between the tab assembly 12 and one side wall of the housing 20 by the second segment 311, the length of the second segment 311 along the first direction Z is less than 15 mm. When a space 40 is formed between the tab assembly 12 and two opposite side walls of the housing 20 by the second segment 311, the length of the second segment 311 along the first direction Z is less than 7.5 mm. This ensures that the energy density and internal pressure range are within a balanced range, reducing the impact on other performance of the battery cell 7.

[0180] Figure 13 is a schematic diagram of a second example of a battery cell provided in some embodiments of this application; Figure 14 is a schematic diagram of a third example of a battery cell provided in some embodiments of this application.

[0181] As shown in Figures 3, 4, 13 and 14, in some embodiments of this application, the housing 20 includes a housing 21 and an end cap 22. The housing has an opening at at least one end along the first direction Z, and the end cap 22 closes the opening. The electrode assembly 10 is at least partially housed within the housing 21, and the electrode terminal 23 is disposed on the end cap 22. A space 40 is formed between the end cap and the housing 21 and the tab assembly 12.

[0182] As shown in Figure 4, the end cap 22 includes a cover plate 221 and a lower plastic 222. The lower plastic is connected to the cover plate 221 to insulate the cover plate from the electrode assembly 10, and the lower plastic 222 abuts against the main body 11 of the electrode assembly 10. The cover plate 221 is used to close the opening and connect to the housing 21. Taking the wound electrode assembly 10 as an example, the separator of the electrode assembly (not shown in the figure) abuts against the lower plastic 222. The lower plastic can be made of corrosion-resistant and high-temperature-resistant materials such as silicone rubber, polyurethane, styrene-butadiene rubber, and polyamide. The lower plastic 222 can be integrally or separately disposed between the cover plate 221 and the electrode assembly 10.

[0183] The space 40 can be placed between the end cap 22 and the tab assembly 12, or it can be placed between the housing 21 and the tab assembly 12.

[0184] In one example, the housing 21 has an opening at one end along the first direction Z, and a cover plate 221 closes to the opening. An electrode assembly 12 extends along one side of the main body 11, and a connecting structure 30 connects the end cap 22 and the electrode assembly 12. A first connector 31 of the connecting structure has a second segment 311 along the first direction Z disposed between the cover plate 221 and the electrode assembly 12. The height of the lower plastic 222 along the first direction Z is greater than 7 mm. Alternatively, when the housing 21 has openings at both ends along the first direction Z, the electrode assembly 12 extends along both sides of the main body 11, forming spaces 40 on both sides of the main body 11, and the height of the lower plastic 222 on both sides along the first direction Z is greater than 3.5 mm.

[0185] Space 40 is formed between one of the end cap 22 and the housing 21 and the tab assembly 12. Space 40, provided for areas with high risk of pressure deformation, improves the stability of the battery cell 7. It also reduces the gas flow path, thereby reducing the risk of pressure deformation in multiple areas of the housing 20.

[0186] As shown in Figures 3 and 13, in some embodiments of this application, the electrode assembly 12 includes a first electrode 121 and a second electrode 122 with opposite polarities. The first electrode and the second electrode are led out from the main body 11 along at least one side of the first direction Z. The first electrode 121 and the second electrode 122 are respectively connected to the corresponding poles in the electrode terminals 23 through the connecting structure 30. A space 40 is formed between the end cap 22 and the first electrode 121 and the second electrode 122.

[0187] The first electrode 121 and the second electrode 122 are provided to extend from the main body portion 11 along at least one side of the first direction Z. For example, the first electrode 121 and the second electrode 122 are extended from the main body portion 11 along one side of the first direction Z, or the first electrode 121 and the second electrode 122 are extended from the main body portion 11 along both sides of the first direction Z.

[0188] The end cap 22 forms a space 40 with the first electrode tab 121 and the second electrode tab 122. For example, the end cap 22 and the first electrode tab 121 and the second electrode tab 122 together form a space 40, or the end cap 22 and the first electrode tab 121 and the second electrode tab 122 respectively form two opposing spaces 40.

[0189] For example, the end cap 22 includes a first end cap 223 and a second end cap 224 disposed opposite to each other. The first end cap is provided with a first electrode terminal 231, and the second end cap 224 is provided with a second electrode terminal 232. The first electrode terminal 231 is connected to a first electrode tab 121 through a connecting structure 30. A first segment 312 is disposed between the first end cap 223 and the first electrode tab 121, forming a space 40. The second electrode terminal 232 is connected to a second electrode tab 122 through another connecting structure 30. The first segment 312 is disposed between the second end cap 224 and the second electrode tab 122, forming another space 40.

[0190] The connection between the end cap 22 and the housing 21 is weaker than other locations. A space 40 is provided between the end cap 22 and the first tab 121 and the second tab 122 to reduce the risk of deformation or even cracking between the end cap 22 and the housing 21 due to internal pressure. When the internal pressure is too high, the gas can be easily discharged from the explosion-proof device of the end cap 22.

[0191] As shown in Figure 3, in some embodiments of this application, the first electrode 121 and the second electrode 122 are extended from the main body 11 along one side of the first direction Z, and the end cap 22 forms a communicating space 40 with the first electrode 121 and the second electrode 122 respectively.

[0192] Specifically, the first tab 121 and the second tab 122 are spaced apart along a third direction Y. A portion of the end cap 22 along the third direction Y forms a space 40 with the first tab 121, and another portion of the end cap 22 along the third direction Y forms another space 40 with the second tab 122. The two spaces are connected along the third direction Y. The second segment 311 of the first connector 31 connected to the first tab 121 has the same height as the second segment 311 of the first connector 31 connected to the first tab 121. The height of the second segment 311 of the first connector 31, which connects to the first tab 121 and the second tab 122 respectively, along the first direction Z is less than 15 mm.

[0193] The first tab 121 and the second tab 122 are placed on one side, which provides better heat dissipation for the battery cell 7. The length of the space 40 can be increased in the direction of the arrangement of the first tab 121 and the second tab 122, thereby increasing the gas storage space.

[0194] As shown in FIG13, in some embodiments of this application, the first electrode 121 and the second electrode 122 are extended from the main body 11 along both sides of the first direction Z, and the end cap 22 forms a space 40 opposite to the first electrode 121 and the second electrode 122 along the first direction Z.

[0195] End cap 22 includes a first end cap 223 and a second end cap 224 disposed opposite to each other. A space 40 is formed between the first end cap 223 and the first electrode tab 121. The height of the second segment 311 of the first connector 31 connecting the first end cap 223 and the first electrode tab 121 is less than 7.5 mm. Another space 40 is formed between the second end cap 224 and the second electrode tab 122. The height of the second segment 311 of the first connector 31 connecting the second end cap 224 and the second electrode tab 122 is less than 7.5 mm.

[0196] The heights of the second segment 311 of the first connector 31 connected to the first electrode 121 and the second segment 311 of the first connector 31 connected to the second electrode 122 can be the same or different.

[0197] The first and second electrode tabs 122 are placed on both sides to improve the current transmission efficiency of the battery cell 7 and form a relative space 40 to facilitate gas dispersion and avoid excessive internal pressure.

[0198] As shown in FIG14, in some embodiments of this application, the electrode assembly 12 includes a first electrode 121 and a second electrode 122 with opposite polarities. The first electrode and the second electrode are led out from the main body 11 on both sides along the first direction Z. The first electrode 121 and the second electrode 122 are respectively connected to the corresponding poles in the electrode terminals 23 through the connecting structure 30. The housing 21 forms a space 40 opposite to the first electrode 121 and the second electrode 122 along the first direction Z.

[0199] The housing 21 has a first sidewall and a second sidewall along the first direction Z. The first sidewall is disposed opposite to the first electrode tab 121, and the second sidewall is disposed opposite to the second electrode tab 122. The first electrode tab 121 is connected to the end cap 22 through a connecting structure 30. A second segment 311 extending along the first direction Z forms a space 40 between the first sidewall and the first electrode tab 121. The second electrode tab 122 is connected to the end cap 22 through another connecting structure 30. A second segment 311 extending along the first direction Z forms another space 40 between the second sidewall and the second electrode tab 122.

[0200] The heights of the second segment 311 on the side of the first electrode 121 and the second segment on the side of the second electrode 122 can be the same or different.

[0201] The first tab 121 and the second tab 122 are led out from both sides of the main body 11 along the first direction Z to achieve more efficient current transmission and more uniform heat distribution. This allows the current to be distributed more evenly on the electrodes during charging and discharging, thereby reducing the risk of local overheating and lithium plating and improving the battery's safety performance. Meanwhile, the end cap 22 is placed on one side of the battery cell 7, which simplifies the structure of the battery cell, reduces manufacturing costs, and improves the reliability and durability of the battery cell 7.

[0202] The shell 21 has a relatively thin wall thickness. In order to reduce the excessive pressure at the gas-generating end of the main body 11 from causing deformation of the shell 21, spaces 40 are respectively provided between the first tab 121 and the second tab 122 and the side walls opposite to the shell 21 to facilitate gas dispersion and avoid excessive internal pressure.

[0203] In other embodiments of this application, the first tab 121 and the second tab 122 are extended from the main body 11 along one side of the first direction Z, and the housing 21 forms a relative space 40 with the first tab 121 and the second tab 122 respectively.

[0204] This application also provides a battery device 2, which includes the battery cell 7 provided in any of the above embodiments.

[0205] This application also provides an electrical device configured to receive electrical energy from the battery device 2 of any of the above embodiments.

[0206] As shown in Figures 3 to 5 and Figure 7, some embodiments of this application provide a battery cell including a housing 20, an electrode assembly 10, and a connecting structure 30. The housing 20 includes a shell 21 and an end cap 22, with electrode terminals 23 disposed on the end cap 22. The electrode assembly 10 is disposed within the shell 21 and includes a main body 11 and a tab assembly 12 extending from the main body 11 along a first direction Z. The tab assembly 12 includes a first tab 121 and a second tab 122 with opposite polarities. The connecting structure 30 connects the tab assembly 12 and the electrode terminals 23. The connecting structure 30 includes a U-shaped second connector 32 and two first connectors 31, which are welded together. The second connector 32 is connected to the first tab 121 and the second tab 122 via the first connectors 31, with the first segment 312 overlapping the tabs of the tab assembly 12 along a second direction X. A space 40 is formed between the end cap 22 and the first tab 121 and the second tab 122. A fusion section is provided between the U-shaped sidewalls of the second connector 32.

[0207] The first connector 31 includes a first segment 312 and a second segment 311. The second segment 311 connects the second connector 32 and the first segment 312. The first segment connects to the first tab 121 and the second tab 122. The second connector 32 connects to the electrode terminal 23. The second segment 311 is disposed between the tab assembly 12 and the end cap 22 along the first direction Z. The height of the second segment 311 along the first direction Z is 12 mm. The maximum height of the tab in the tab assembly 12 along the first direction Z is less than or equal to 30 mm.

[0208] The tab assembly 12 extends along the first direction Z. Along the first direction Z, the first segment 312 can partially overlap with the tab assembly 12. Along the third direction Y, the first segment 312 can be placed in the middle of the tab of the tab assembly 12.

[0209] The end cap 22 includes a cover plate 221 and a lower plastic part 222. The lower plastic part is connected to the cover plate 221 to insulate the cover plate from the electrode assembly 10, and the lower plastic part 222 abuts against the main body 11 of the electrode assembly 10. The cover plate 221 is used to close the opening and connect to the housing 21.

[0210] The first direction Z is the height direction of the battery cell 7, the second direction X is the width direction of the battery cell 7, and the third direction Y is the length direction of the battery cell 7.

[0211] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: The housing includes a first wall, wherein electrode terminals are disposed on the first wall; An electrode assembly is disposed within the housing, the electrode assembly comprising a main body and a tab assembly extending from the main body along a first direction; The connection structure includes a first connector and a second connector that are interconnected. The first connector extends at least partially along the first direction and is connected to the tab assembly. The second connector is connected to the electrode terminal. A space is formed between the housing and the main body. The height of the space along the first direction ranges from 5 to 40 millimeters.

2. The battery cell according to claim 1, wherein, The height of the space along the first direction ranges from 8 to 20 millimeters.

3. The battery cell according to claim 1 or 2, wherein, The first connector includes a first segment and a second segment, the second segment connects the second connector and the first segment, the first segment is connected to the tab assembly, and the second segment is disposed along a first direction between the tab assembly and the side wall of the housing.

4. The battery cell according to claim 3, wherein, Both the electrode assembly and the first segment extend along the first direction and overlap and connect along the second direction, with the first direction intersecting the second direction.

5. The battery cell according to claim 3, wherein, The first segment and the second segment are set at an angle. The end of the electrode assembly that is away from the main body extends along the second direction and overlaps and connects with the first segment along the first direction. The first direction and the second direction intersect.

6. The battery cell according to claim 5, wherein, The tab assembly is at least partially connected along the first direction to the side of the first segment opposite to the main body.

7. The battery cell according to claim 5 or 6, wherein, Along the width direction of the battery cell, the first segment faces inward relative to the second segment.

8. The battery cell according to claim 5 or 6, wherein, Along the width direction of the battery cell, the first segment faces outward relative to the second segment of the battery cell.

9. The battery cell according to any one of claims 5 to 8, wherein, The second connector extends along the second direction and is connected to the second segment by welding or bonding.

10. The battery cell according to any one of claims 1 to 8, wherein, The first connector and the second connector are integrally formed structures.

11. The battery cell according to any one of claims 1 to 10, wherein, The housing includes a shell and an end cap. The shell has an opening at at least one end along the first direction, and the end cap closes the opening. The electrode assembly is at least partially housed within the shell, and the electrode terminals are disposed on the end cap. The space is formed between the end cap and the shell and the electrode assembly.

12. The battery cell according to claim 11, wherein, The electrode assembly includes a first electrode and a second electrode with opposite polarities. The first electrode and the second electrode are led out from at least one side of the main body along the first direction. The first electrode and the second electrode are respectively connected to the corresponding poles in the electrode terminals through the connection structure. The space is formed between the end cap and the first electrode tab and the second electrode tab.

13. The battery cell according to claim 12, wherein, The first electrode and the second electrode are extended from one side of the main body along the first direction, and the end cap forms a communicating space with the first electrode and the second electrode, respectively.

14. The battery cell according to claim 12, wherein, The first electrode and the second electrode are extended from both sides of the main body along the first direction, and the end caps form spaces opposite to the first electrode and the second electrode along the first direction.

15. The battery cell according to claim 11, wherein, The electrode assembly includes a first electrode and a second electrode with opposite polarities. The first electrode and the second electrode are led out from both sides of the main body along the first direction. The first electrode and the second electrode are respectively connected to the corresponding poles in the electrode terminals through the connection structure. The housing forms a space with respect to the first electrode and the second electrode, respectively, along the first direction.

16. A battery device, wherein, Includes the battery cell according to any one of claims 1 to 15.

17. An electrical appliance, wherein, The electrical device is configured to receive electrical energy supplied from the battery device of claim 16.

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