Battery cell, battery, and electric device

Abstract

Disclosed in embodiments of the present application are a battery cell, a battery, and an electric device. The battery cell comprises: a plurality of walls, wherein the plurality of walls include a first wall, a second wall and a third wall, the first wall and the second wall are arranged opposite to each other, and the third wall is used for connecting the first wall to the second wall; an electrode assembly, wherein a first end face of the electrode assembly is provided with a first tab and a second tab of opposite polarity, and the first end face is the end face of the electrode assembly facing the third wall; a first electrode terminal arranged on the first wall and electrically connected to the first tab; a second electrode terminal arranged on the second wall and electrically connected to the second tab; and a pressure relief mechanism arranged on the third wall. The battery cell, the battery, and the electric device of the embodiments of the present application can improve the reliability of the battery.

Description

Battery cells, batteries and electrical equipment

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410107299.4, filed on January 25, 2024, entitled “Battery Cell, Battery and Electrical Equipment,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Art

[0004] Energy conservation and emission reduction are key to the sustainable development of the automotive industry. In this context, electric vehicles, due to their energy-saving and environmentally friendly advantages, have become a crucial component of the industry's sustainable development. Battery technology, in turn, is a crucial factor in the development of electric vehicles.

[0005] In the development of battery technology, in addition to improving battery performance, safety is also an issue that cannot be ignored. If battery safety cannot be guaranteed, the battery will be unusable. Therefore, how to enhance battery safety and reliability is a key technical issue in the development of battery technology.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can improve the reliability of the battery.

[0008] In a first aspect, a battery cell is provided, which includes: a plurality of walls, the plurality of walls including a first wall, a second wall and a third wall, the first wall and the second wall being arranged opposite to each other, and the third wall being used to connect the first wall and the second wall; an electrode assembly, a first end face of the electrode assembly being provided with a first electrode tab and a second electrode tab with opposite polarities, the first end face being the end face of the electrode assembly facing the third wall; a first electrode terminal, provided on the first wall, the first electrode terminal being used to be electrically connected to the first electrode tab; a second electrode terminal, provided on the second wall, the second electrode terminal being used to be electrically connected to the second electrode tab; and a pressure relief mechanism, provided on the third wall.

[0009] Therefore, in the battery cell of the embodiment of the present application, the two tabs of the electrode assembly are arranged on the same end face, which can reduce the size of the electrode assembly in the direction perpendicular to the first end face, and thus reduce the size of the battery cell in this direction. The two electrode terminals are respectively arranged on two opposite walls, and the two tabs correspond to different walls, which can further reduce the size of the battery cell in the direction perpendicular to the first end face, thereby improving the space utilization inside the battery. Furthermore, the pressure relief mechanism and the two electrode terminals are respectively located on different walls. In this way, when the internal pressure or temperature of the battery cell reaches a predetermined threshold and thermal runaway occurs, the impact of the emissions discharged through the pressure relief mechanism on the two electrode terminals can be reduced, reducing the risk of heat diffusion inside the battery where the battery cell experiencing thermal runaway is located. It can also reduce the risk of explosion of the battery, thereby improving the reliability of the battery.

[0010] In some embodiments, the battery cell further includes: a shell, the shell being used to accommodate the electrode assembly, the shell having a first opening and a second opening arranged opposite to each other, and the third wall being the wall of the shell; a first cover plate, the first cover plate being used to cover the first opening, the first cover plate being the first wall; and a second cover plate being used to cover the second opening, the second cover plate being the second wall. When assembling the battery cell, the electrode assembly can enter the interior of the shell from any opening of the shell, and then the first cover plate can be used to cover the first opening, and the second cover plate can be used to cover the second opening, so as to improve processing efficiency. In addition, during the use of the battery cell, if the electrode assembly expands, the risk of connection failure between the shell and the two cover plates can be reduced, thereby improving the structural strength and stability of the battery cell.

[0011] In some embodiments, the battery cell further includes: a first connecting member for connecting the first tab to the first electrode terminal, the first connecting member comprising a first connecting portion and a second connecting portion bent relative to each other, the first connecting portion being electrically connected to the first tab, and the second connecting portion being electrically connected to the first electrode terminal; and a second connecting member for connecting the second tab to the second electrode terminal, the second connecting member comprising a third connecting portion and a fourth connecting portion bent relative to each other, the third connecting portion being electrically connected to the second tab, and the fourth connecting portion being electrically connected to the second electrode terminal. By bending the first and second connecting members, the first electrode terminal can be positioned on a different side from the first tab, and the second electrode terminal can be positioned on a different side from the second tab, resulting in a simple structure and ease of implementation.

[0012] In some embodiments, the first connecting member and / or the second connecting member are integrally formed. This can save the connection step between the first and second connecting parts, and also save the connection step between the third and fourth connecting parts, simplifying the structure of the first and / or second connecting members, simplifying the assembly process of the battery cells, and improving the installation efficiency of the battery cells.

[0013] In some embodiments, the first connection portion is perpendicular to the second connection portion; and / or the third connection portion is perpendicular to the fourth connection portion, so as to save space.

[0014] In some embodiments, the first wall is provided with a first groove that is recessed toward the interior of the battery cell; and / or the second wall is provided with a second groove that is recessed toward the interior of the battery cell. If the electrode assembly expands, the first groove of the first wall can provide a deformation margin for the first wall to undergo tensile deformation, thereby reducing the risk of cracking between the first wall and other connected walls; the second groove can provide a deformation margin for the second wall to undergo tensile deformation, thereby reducing the risk of cracking between the second wall and other connected walls.

[0015] In some embodiments, the first groove is an annular groove that surrounds the edge of the first wall; and / or the second groove is an annular groove that surrounds the edge of the second wall. This not only facilitates processing, but also ensures uniform distribution of deformation between the first and second walls, providing deformation allowances for tensile deformation in all directions of the first and second walls, thereby improving structural stability.

[0016] In some embodiments, the battery cell further includes: an insulating component, which is disposed between the first end surface and the third wall and can be used to achieve electrical insulation between the tab and the third wall and to support the third wall.

[0017] In some embodiments, the insulating component is provided with a pressure relief hole, which is used to avoid the pressure relief mechanism so as to be actuated in time when the internal pressure or temperature of the battery cell reaches a predetermined threshold, thereby timely releasing the internal pressure or temperature of the battery cell.

[0018] In some embodiments, the electrode assembly includes a first electrode sheet and a second electrode sheet of opposite polarity, the first electrode sheet being connected to the first electrode tab, the second electrode sheet being connected to the second electrode tab, and the first and second electrode sheets being wound along a winding axis that is perpendicular to the first end face. The wound electrode assembly simplifies the manufacturing process and can improve the processing efficiency of the battery cells.

[0019] In some embodiments, the electrode assembly includes multiple first pole pieces and multiple second pole pieces, the first pole piece has opposite polarity to the second pole piece, the first pole piece is connected to the first pole ear, and the second pole piece is connected to the second pole ear, and the multiple first pole pieces and the multiple second pole pieces are alternately stacked along a stacking direction, and the stacking direction is parallel to the first end face.

[0020] In some embodiments, the electrode assembly includes a first electrode plate and multiple second electrode plates, the first electrode plate has opposite polarity to the second electrode plate, the first electrode plate is connected to the first electrode ear, and the second electrode plate is connected to the second electrode ear. The first electrode plate includes multiple stacking sections and at least one bending section, and the bending section is used to connect two adjacent stacking sections. The multiple stacking sections and the multiple second electrode plates are alternately stacked along a stacking direction, and the stacking direction is parallel to the first end face.

[0021] The stacked electrode assembly is simple to process and can fully utilize the internal space of the battery cell, thereby improving space utilization and further increasing the energy density of the battery cell.

[0022] In a second aspect, a battery is provided, comprising: a plurality of battery cells, wherein the battery cells are the battery cells described in the first aspect or any one embodiment of the first aspect.

[0023] In a third aspect, an electrical device is provided, comprising: a battery, the battery comprising the battery cell described in the first aspect or any one embodiment of the first aspect, the battery being used to power the electrical device.

[0024] In some embodiments, the electrical equipment is a vehicle, a ship, or a spacecraft. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG1 is a schematic diagram of a vehicle according to an embodiment of the present application;

[0026] FIG2 is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application;

[0027] FIG3 is a schematic structural diagram of a battery cell according to an embodiment of the present application;

[0028] FIG4 is a front view schematic diagram of a battery cell according to an embodiment of the present application;

[0029] FIG5 is a schematic diagram of the exploded structure of a battery according to an embodiment of the present application;

[0030] FIG6 is a schematic structural diagram of an electrode assembly and a connecting member according to an embodiment of the present application;

[0031] FIG7 is an expanded schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0032] FIG8 is a schematic structural diagram of a wound electrode assembly according to an embodiment of the present application;

[0033] FIG9 is a schematic diagram of a partially expanded structure of a wound electrode assembly according to one embodiment of the present application;

[0034] FIG10 is a schematic diagram of a partially expanded structure of a stacked electrode assembly according to one embodiment of the present application;

[0035] FIG11 is a schematic top view of a partially expanded structure of a stacked electrode assembly according to one embodiment of the present application;

[0036] FIG12 is a schematic structural diagram of a stacked electrode assembly according to an embodiment of the present application;

[0037] FIG13 is another schematic structural diagram of a stacked electrode assembly according to one embodiment of the present application;

[0038] FIG14 is a schematic structural diagram of multiple stacked electrode assemblies according to an embodiment of the present application;

[0039] FIG15 is another schematic structural diagram of a plurality of stacked electrode assemblies according to an embodiment of the present application;

[0040] FIG16 is another schematic structural diagram of an electrode assembly and a connecting member according to an embodiment of the present application;

[0041] FIG17 is a schematic structural diagram of a first wall or a second wall according to an embodiment of the present application;

[0042] FIG18 is a schematic front view of the structure of the first wall or the second wall according to an embodiment of the present application;

[0043] FIG19 is a schematic structural diagram of an insulating component according to an embodiment of the present application.

[0044] In the drawings, the drawings are not drawn to scale. DETAILED DESCRIPTION

[0045] The technical solutions in the embodiments of the present application will be described below with reference to the accompanying drawings.

[0046] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0047] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0048] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0049] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0050] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0051] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0052] The term "multiple" in this application refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0053] In the embodiment of the present application, the battery cell may be a secondary battery. A secondary battery refers to a battery cell that can be continuously used by activating active materials by charging after the battery cell is discharged.

[0054] The battery cells can be lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-hydrogen batteries, nickel-cadmium batteries, lead-acid batteries, etc., which are not limited in the embodiments of the present application.

[0055] A battery cell typically includes an electrode assembly. This assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of a battery cell, active ions (such as lithium ions) are inserted and removed between the positive and negative electrodes. The separator, placed between the positive and negative electrodes, prevents short circuits between the positive and negative electrodes while allowing the active ions to pass through.

[0056] 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.

[0057] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0058] 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.

[0059] 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 specifically limit the type of electrolyte, and the electrolyte can be selected based on needs. The electrolyte can be liquid, gel, or solid.

[0060] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or polygonal.

[0061] In some embodiments, the electrode assembly is provided with tabs that can conduct current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0062] In some embodiments, a battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and electrolyte. The housing may be a steel housing, an aluminum housing, a plastic housing (e.g., polypropylene), a composite metal housing (e.g., a copper-aluminum composite housing), or an aluminum-plastic film. The housing includes a shell and a cover.

[0063] As an example, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a soft-pack battery cell or a battery cell of other shapes. The prismatic battery cell includes a square-shell battery cell, a blade-shaped battery cell, and a polygonal battery. The polygonal battery is, for example, a hexagonal battery, etc. There is no special limitation in this application.

[0064] The battery mentioned in the embodiments of the present application may include one or more battery cells to provide a single physical module with higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid through a busbar.

[0065] In some embodiments, the battery may be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0066] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, wherein the battery cells or battery modules are housed in the case.

[0067] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0068] Current battery cells typically include a housing and an electrode assembly housed within the housing. The housing is a hollow structure with an open end. The housing is filled with electrolyte, and the housing opening is covered by a cover. The cover is typically provided with electrode terminals and a pressure relief mechanism. The electrode terminals are electrically connected to the tabs of the electrode assembly to output electrical energy from the battery cell. The pressure relief mechanism is designed to activate when the internal pressure or temperature of the battery cell reaches a predetermined threshold, thereby releasing the internal pressure or temperature of the battery cell. However, when thermal runaway occurs due to the internal pressure or temperature of the battery cell reaching the predetermined threshold, a large amount of emissions is discharged through the pressure relief mechanism. These emissions typically include conductive particles. These conductive particles splash onto the electrode terminals surrounding the pressure relief mechanism, potentially causing a short circuit between the electrode terminals of different battery cells, leading to thermal diffusion and even explosion, seriously affecting the safety performance of the battery.

[0069] Therefore, the embodiments of the present application provide a battery cell, a battery and an electrical device that can solve the above-mentioned problems. The battery cell tried in the present application includes a plurality of walls, wherein the plurality of walls include a first wall, a second wall and a third wall. The first wall and the second wall are arranged opposite to each other, and the third wall is used to connect the first wall and the second wall. The battery cell also includes an electrode assembly, and the first pole ear and the second pole ear of the electrode assembly with opposite polarities are both located on the first end face of the electrode assembly, and the first end face is the end face of the electrode assembly facing the third wall. Arranging the two pole ears of the electrode assembly on the same end face can reduce the size of the electrode assembly in a direction perpendicular to the first end face, thereby reducing the size of the battery cell in this direction.

[0070] The battery cell also includes a first electrode terminal and a second electrode terminal of opposite polarity. The first electrode terminal is disposed on the first wall for electrical connection to the first tab, and the second electrode terminal is disposed on the second wall for electrical connection to the second tab. Placing the two electrode terminals on two opposing walls, with different walls corresponding to the two tabs, can further reduce the size of the battery cell in a direction perpendicular to the first end face, thereby improving space utilization within the battery.

[0071] The battery cell also includes a pressure relief mechanism located on the third wall. The pressure relief mechanism and the two electrode terminals are located on separate walls. This reduces the impact of emissions from the pressure relief mechanism on the two electrode terminals when the internal pressure or temperature of the battery cell reaches a predetermined threshold, leading to thermal runaway. This reduces the risk of heat diffusion within the battery cell where the thermal runaway cell is located, reduces the risk of explosion, and improves battery reliability.

[0072] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use batteries.

[0073] Electrical equipment can be vehicles, mobile phones, portable devices, laptops, ships, spacecraft, electric toys, and electric tools, etc. Vehicles can be fuel vehicles, gas vehicles, or new energy vehicles. New energy vehicles can be pure electric vehicles, hybrid vehicles, or extended-range vehicles, etc. Spacecraft include airplanes, rockets, space shuttles, and spacecraft, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators, and electric planers, etc. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical equipment.

[0074] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0075] For example, as shown in FIG1 , it is a structural diagram of a vehicle 1 according to an embodiment of the present application. The vehicle 1 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A motor 40, a controller 30 and a battery 10 may be provided inside the vehicle 1. The controller 30 is used to control the battery 10 to supply power to the motor 40. For example, a battery 10 may be provided at the bottom, front or rear of the vehicle 1. The battery 10 may be used to power the vehicle 1. For example, the battery 10 may be used as an operating power source for the vehicle 1, for the circuit system of the vehicle 1, for example, for the working power requirements during the start-up, navigation and operation of the vehicle 1. In another embodiment of the present application, the battery 10 may not only be used as an operating power source for the vehicle 1, but also as a driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0076] For example. Figure 2 shows a partial structural schematic diagram of the battery 10 of an embodiment of the present application. As shown in Figure 2, the battery 10 of the embodiment of the present application may include a plurality of battery cells 20 to meet different power usage requirements. As shown in Figure 2, the battery 10 of the embodiment of the present application may also include a box body 11, which can be used to accommodate a plurality of battery cells 20. The interior of the box body 11 of the embodiment of the present application is a hollow structure, and a plurality of battery cells 20 are accommodated in the box body 11. The box body 11 may include two parts, referred to here as a first box body part 111 and a second box body part 112, and the first box body part 111 and the second box body part 112 are buckled together. The shape of the first box body part 111 and the second box body part 112 can be determined according to the shape of the components contained inside, for example, it can be determined according to the shape of the combination of the plurality of battery cells 20 contained inside.

[0077] It should be understood that at least one of the first housing portion 111 and the second housing portion 112 has an opening. For example, as shown in FIG2 , the first housing portion 111 and the second housing portion 112 can both be hollow rectangular parallelepipeds, each with one open face. The opening of the first housing portion 111 and the opening of the second housing portion 112 are arranged opposite each other, and the first housing portion 111 and the second housing portion 112 are interlocked to form a housing 11 having a closed chamber, which can be used to accommodate multiple battery cells 20. The multiple battery cells 20 are connected in parallel, series, or in a mixed combination and placed in the housing 11 formed by the interlocking of the first housing portion 111 and the second housing portion 112.

[0078] For another example, unlike that shown in FIG2 , only one of the first and second housing portions 111, 112 may be a hollow rectangular parallelepiped with an opening, while the other may be a plate-shaped structure covering the opening. For example, if the second housing portion 112 is a hollow rectangular parallelepiped structure with a single opening, and the first housing portion 111 is a plate-shaped structure, the first housing portion 111 covers the opening of the second housing portion 112 to form the housing 11 with a closed chamber, which can be used to accommodate multiple battery cells 20.

[0079] In some embodiments, the battery 10 may further include a busbar component, which may be used to achieve electrical connection between multiple battery cells 20, such as parallel connection, series connection, or hybrid connection. Specifically, the busbar component may achieve electrical connection between the battery cells 20 by connecting the electrode terminals of the battery cells 20; alternatively, the busbar component may also achieve electrical connection between the battery cells 20 by connecting other components of the battery cells 20. For example, the busbar component may be electrically connected to the sealing structure or housing of the battery cells 20, thereby achieving electrical connection between the battery cells 20. Furthermore, the busbar component may be fixed to the corresponding components of the battery cells 20 by welding, for example, it may be fixed to the electrode terminals, sealing structure, or housing, etc., by welding, but the embodiments of the present application are not limited thereto.

[0080] Figure 3 shows a structural schematic diagram of a battery cell 20 according to an embodiment of the present application; Figure 4 shows a front view schematic diagram of a battery cell 20 according to an embodiment of the present application, for example, Figure 4 may be a front view of the battery cell 20 shown in Figure 3; Figure 5 shows a decomposed structural schematic diagram of a battery cell 20 according to an embodiment of the present application, for example, Figure 5 may be a decomposed structural schematic diagram of the battery cell 20 shown in Figures 3 and 4.

[0081] As shown in Figures 3 to 5, the battery cell 20 of the present embodiment may include multiple walls, including a first wall 211, a second wall 212, and a third wall 213. The first wall 211 and the second wall 212 are disposed opposite each other, and the third wall 213 is used to connect the first wall 211 and the second wall 212. The battery cell 20 of the present embodiment may also include an electrode assembly 22. The first end surface 223 of the electrode assembly 22 is provided with a first electrode tab 2221 and a second electrode tab 2222 of opposite polarity. The first end surface 223 is the end surface of the electrode assembly 22 facing the third wall 213. The battery cell 20 of the present embodiment may also include a first electrode terminal 231 and a second electrode terminal 232. The first electrode terminal 231 is disposed on the first wall 211 and is electrically connected to the first electrode tab 2221. The second electrode terminal 232 is disposed on the second wall 212 and is electrically connected to the second electrode tab 2222. The battery cell 20 of the embodiment of the present application may further include a pressure relief mechanism 24 , which is disposed on the third wall 213 .

[0082] It should be understood that the battery cell 20 of the embodiment of the present application includes multiple walls, which can be used to form a polyhedral hollow structure to accommodate the electrode assembly 22. For example, the embodiment of the present application is mainly described by taking the rectangular battery cell 20 as an example, but the embodiment of the present application is not limited thereto.

[0083] The first wall 211, the second wall 212 and the third wall 213 of the embodiment of the present application are any three walls of the battery cell 20. Specifically, the first wall 211 and the second wall 212 are arranged relative to each other, that is, the first wall 211 and the second wall 212 are not directly connected. For example, taking the rectangular battery cell 20 as an example, the first wall 211 and the second wall 212 can be any two walls of the battery cell 20 that are arranged relative to each other and parallel to each other. The third wall 213 of the embodiment of the present application is used to connect the first wall 211 and the second wall 212, wherein the third wall 213 can be directly connected to the first wall 211 or indirectly connected through other walls. Similarly, the third wall 213 can be directly connected to the second wall 212 or indirectly connected through other walls. For example, taking the rectangular battery cell 20 as an example, the third wall 213 can be a wall directly connected to the first wall 211 and the second wall 212.

[0084] It should be understood that the electrode assembly 22 of the embodiment of the present application may include a tab 222, which can conduct current from the electrode assembly 22. Specifically, the tabs 222 of the electrode assembly 22 include a first tab 2221 and a second tab 2222 of opposite polarity. The two tabs 222 are both located on the first end surface 223 of the electrode assembly 22, that is, the two tabs 222 extend from the same side of the electrode assembly 22. Providing the two tabs 222 of the electrode assembly 22 on the same end surface can reduce the size of the electrode assembly 22 in a direction perpendicular to the first end surface 223. For example, taking the height direction Z of the electrode assembly 22 as an example, which is perpendicular to the first end surface 223, the size of the electrode assembly 22 in the height direction Z can be reduced, thereby reducing the size of the battery cell 20 in the height direction Z.

[0085] In some embodiments, the first electrode tab 2221 of the embodiment of the present application can be a positive electrode tab, and the second electrode tab 2222 is a negative electrode tab; or, the first electrode tab 2221 can be a negative electrode tab, and the second electrode tab 2222 is a positive electrode tab. The embodiment of the present application is not limited to this.

[0086] In some embodiments, the electrode assembly 22 may include at least one first electrode tab 2221 and at least one second electrode tab 2222. The embodiments of the present application mainly take any one first electrode tab 2221 and a corresponding one second electrode tab 2222 of the electrode assembly 22 as an example. For example, as shown in Figures 3 to 5, the electrode assembly 22 may include one first electrode tab 2221 and one second electrode tab 2222, but the embodiments of the present application are not limited thereto.

[0087] It should be understood that in the embodiment of the present application, the first electrode terminal 231 disposed on the first wall 211 is electrically connected to the first electrode tab 2221, and the second electrode terminal 232 disposed on the second wall 212 is electrically connected to the second electrode tab 2222. Because the two electrode terminals are located on different walls, and the walls where the two electrode terminals are located are different from the walls corresponding to the electrode tab 222, the size of the battery cell 20 in a direction perpendicular to the first end face 223 can be further reduced. For example, the size of the battery cell 20 in the height direction Z of the electrode assembly 22 can be reduced, thereby improving the space utilization within the battery 10.

[0088] In the embodiment of the present application, the first electrode terminal 231 can be a positive electrode terminal, and the second electrode terminal 232 can be a negative electrode terminal; alternatively, the first electrode terminal 231 can be a negative electrode terminal, and the second electrode terminal 232 can be a positive electrode terminal. The embodiment of the present application is not limited to this.

[0089] In some embodiments, the battery cell 20 may include at least one first electrode terminal 231 and at least one second electrode terminal 232. The present embodiment primarily uses any one first electrode terminal 231 and a corresponding one second electrode terminal 232 of the battery cell 20 as an example. For example, the battery cell 20 of the present embodiment may include multiple first electrode terminals 231, each of which may be located on the first wall 211. The battery cell 20 of the present embodiment may also include multiple second electrode terminals 232, each of which may be located on the second wall 212, but the present embodiment is not limited thereto. As shown in Figures 3 to 5, the battery cell 20 is taken as an example, including one first electrode terminal 231 and one second electrode terminal 232.

[0090] In the embodiment of the present application, the battery cell 20 also includes a pressure relief mechanism 24 arranged on the third wall 213. Since the pressure relief mechanism 24 and the two electrode terminals are located on different walls, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold and thermal runaway occurs, the impact of the emissions discharged through the pressure relief mechanism 24 on the two electrode terminals can be reduced, thereby reducing the risk of heat diffusion inside the battery 10 caused by the battery cell 20 that has thermal runaway. The risk of explosion of the battery 10 can also be reduced, thereby improving the reliability of the battery 10.

[0091] It should be understood that the pressure relief mechanism 24 in the present embodiment refers to a component or element that is activated to relieve the internal pressure or temperature of the battery cell 20 when the internal pressure or temperature reaches a predetermined threshold. This threshold value varies depending on the design requirements. This threshold value may depend on the material of one or more of the positive electrode sheet, negative electrode sheet, electrolyte, and separator in the battery cell 20.

[0092] The "activation" mentioned in this application means that the pressure relief mechanism 24 is in action or activated to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The action produced by the pressure relief mechanism 24 may include but is not limited to: at least a part of the pressure relief mechanism 24 is broken, shattered, torn or opened, etc. When the pressure relief mechanism 24 is actuated, the high-temperature and high-pressure substances inside the battery cell 20 will be discharged outward from the actuated part as emissions. In this way, the pressure and temperature of the battery cell 20 can be relieved under controllable pressure or temperature, thereby avoiding potential more serious accidents.

[0093] The emissions from the battery cells 20 mentioned in this application include, but are not limited to: electrolyte, dissolved or split positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gas generated by the reaction, flames, etc.

[0094] In the embodiment of the present application, the pressure relief mechanism 24 is disposed on the third wall 213 of the battery cell 20. The pressure relief mechanism 24 can be a portion of the third wall 213 or a separate structure from the third wall 213, secured to the third wall 213 by, for example, welding. The embodiment of the present application is not limited thereto. For example, when the pressure relief mechanism 24 is a portion of the third wall 213, the pressure relief mechanism 24 can be formed by providing a notch in the third wall 213. The thickness of the third wall 213 corresponding to the notch is less than the thickness of the pressure relief mechanism 24 in the area other than the notch. The notch is the weakest point of the pressure relief mechanism 24. When excessive gas is generated by the battery cell 20, causing the internal pressure to rise to a threshold, or when heat is generated by reactions within the battery cell 20, causing the internal temperature of the battery cell 20 to rise to a threshold, the pressure relief mechanism 24 can rupture at the notch, allowing the inside and outside of the battery cell 20 to communicate. The gas pressure and temperature are released outward through the rupture of the pressure relief mechanism 24, thereby preventing the battery cell 20 from exploding.

[0095] For another example, the pressure relief mechanism 24 may also be a separate structure from the third wall 213. The pressure relief mechanism 24 may be in the form of an explosion-proof valve, an air valve, a pressure relief valve or a safety valve, and may specifically adopt a pressure-sensitive or temperature-sensitive element or structure. That is, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, the pressure relief mechanism 24 executes an action or the weak structure provided in the pressure relief mechanism 24 is destroyed, thereby forming an opening or channel for the internal pressure or temperature to be released.

[0096] It should be understood that the battery cell 20 of the present embodiment further includes a housing 214, a first cover plate 215, and a second cover plate 216. Specifically, the housing 214 is used to accommodate the electrode assembly 22 and has a first opening 2141 and a second opening 2142 oppositely disposed therebetween. The first cover plate 215 is used to cover the first opening 2141, and the second cover plate 216 is used to cover the second opening 2142.

[0097] The material of the shell 214 of the embodiment of the present application can include various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc. The shell 214 can be of various shapes, such as a cylinder, a rectangular parallelepiped, etc. For example, as shown in Figures 3 to 5, the embodiment of the present application mainly takes the shell 214 as a rectangular parallelepiped as an example; for example, the shell 214 has two openings, namely a first opening 2141 and a second opening 2142, and the two openings are two opposite surfaces of the shell 214. This structure with openings at both ends facilitates the assembly of the internal electrode assembly 22. The electrode assembly 22 can enter the shell 214 through any opening, which can improve the processing efficiency of the battery cell 20.

[0098] The first cover plate 215 of the embodiment of the present application is used to cover the first opening 2141 of the shell 214, and the second cover plate 216 is used to cover the second opening 2142 of the shell 214, thereby isolating the internal environment of the battery cell 20 from the external environment. The materials of the two cover plates can be the same or different. For example, the two cover plates are generally made of the same material to facilitate processing. The material of each cover plate in the embodiment of the present application can also be a variety of materials, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the material of the two cover plates can be the same as or different from the material of the shell 214.

[0099] It should be understood that the shape of each cover plate in the embodiment of the present application can be adapted to the shape of the housing 214. For example, as shown in Figures 3 to 5, when the housing 214 is a rectangular parallelepiped structure, the first cover plate 215 and the second cover plate 216 can have the same shape, for example, both are plate-shaped structures adapted to the housing 214; or, unlike the embodiment shown in Figures 3 to 5, the first cover plate 215 and the second cover plate 216 can also be shaped as a hollow rectangular parallelepiped structure with one end open, so that the two cover plates and the housing 214 form a rectangular battery cell 20. Alternatively, the first cover plate 215 and the second cover plate 216 can have different shapes, and the embodiment of the present application is not limited to this.

[0100] In some embodiments, the third wall 213 is a wall of the housing 214; the first cover plate 215 is the first wall 211; and the second cover plate 216 is the second wall 212. During assembly of the battery cell 20, the electrode assembly 22 can be inserted into the housing 214 through any opening in the housing. The first cover plate 215 then covers the first opening 2141, and the second cover plate 216 covers the second opening 2142, thereby improving processing efficiency. Furthermore, as shown in Figures 3 to 5, considering that the two tabs 222 of the electrode assembly 22 are located on the first end surface 223, the first end surface 223 is perpendicular to the height direction Z of the electrode assembly 22. During use of the battery cell 20, the electrode assembly 22 typically expands along its thickness direction. For example, if the thickness direction of the electrode assembly 22 is the width direction Y of the electrode assembly 22, the electrode assembly 22 will experience significant dimensional changes along its width direction Y during the charge and discharge process of the battery cell 20. The two openings of the housing 214 are arranged opposite each other along the length direction X of the electrode assembly 22. Therefore, the housing 214 can effectively limit the expansion of the electrode assembly 22, reducing the dimensional changes of the battery cell 20 during use. Furthermore, due to the limited strength of the connection between the housing 214 and each cover plate, compared to arranging the two cover plates in other locations, when the third wall 213 serves as a wall of the housing 214, the first cover plate 215 serves as the first wall 211, and the second cover plate 216 serves as the second wall 212, the risk of connection failure between the housing 214 and the two cover plates can be reduced, thereby improving the structural strength and stability of the battery cell 20.

[0101] It should be understood that in the embodiment of the present application, the first electrode terminal 231 and the first electrode tab 2221 can be directly or indirectly connected, and the second electrode terminal 232 and the second electrode tab 2222 can also be directly or indirectly connected. The following description, with reference to the accompanying drawings, primarily uses the indirect connection between the first electrode terminal 231 and the first electrode tab 2221, and the indirect connection between the second electrode terminal 232 and the second electrode tab 2222 as examples.

[0102] In the embodiment of the present application, the battery cell 20 further includes a first connecting member 261 and a second connecting member 262, wherein the first connecting member 261 is used to connect the first electrode tab 2221 to the first electrode terminal 231, and the second connecting member 262 is used to connect the second electrode tab 2222 to the second electrode terminal 232. The structures of the first connecting member 261 and the second connecting member 262 in the embodiment of the present application can be configured according to actual applications to achieve the arrangement of the electrode terminal and the electrode tab on different sides.

[0103] Figure 6 shows a schematic diagram of the structure of an electrode assembly 22, a first connecting member 261, and a second connecting member 262 according to an embodiment of the present application. For example, the electrode assembly 22, the first connecting member 261, and the second connecting member 262 shown in Figure 6 may be part of the structure of the battery cell 20 shown in Figures 3 to 5. As shown in Figures 5 and 6, the electrical connection between the electrode terminals and the corresponding tabs can be achieved by bending the first connecting member 261 and the second connecting member 262.

[0104] In some embodiments, the first connecting member 261 includes a first connecting portion 2611 and a second connecting portion 2612 that are relatively bent. The first connecting portion 2611 is used to electrically connect to the first electrode tab 2221, and the second connecting portion 2612 is used to electrically connect to the first electrode terminal 231. The second connecting member 262 includes a third connecting portion 2621 and a fourth connecting portion 2622 that are relatively bent. The third connecting portion 2621 is used to electrically connect to the second electrode tab 2222, and the fourth connecting portion 2622 is used to electrically connect to the second electrode terminal 232. By bending the first and second connecting members 261 and 262, the first electrode terminal 231 can be positioned on a different side from the first electrode tab 2221, and the second electrode terminal 232 can be positioned on a different side from the second electrode tab 2222. This structure is simple and easy to implement.

[0105] In some embodiments, the first connecting member 261 is an integrally formed structure; and / or the second connecting member 262 is an integrally formed structure. Providing the first connecting member 261 as an integrally formed structure can save the connection step between the first connecting portion 2611 and the second connecting portion 2612; similarly, providing the second connecting member 262 as an integrally formed structure can save the connection step between the third connecting portion 2621 and the fourth connecting portion 2622, simplifying the structure of the first connecting member 261 and / or the second connecting member 262, simplifying the assembly process of the battery cell 20, and improving the installation efficiency of the battery cell 20.

[0106] In some embodiments, the first connecting portion 2611 is perpendicular to the second connecting portion 2612; and / or the third connecting portion 2621 is perpendicular to the fourth connecting portion 2622. The right-angled first connecting member 261 can save space, especially when the first wall 211 is perpendicular to the third wall 213. Arranging the first connecting portion 2611 perpendicular to the second connecting portion 2612 facilitates electrical connection between the first electrode terminal 231 and the first tab 2221 while reducing the space occupied by the first connecting member 261 within the battery cell 20. Similarly, the right-angled second connecting member 262 can save space, especially when the second wall 212 is perpendicular to the third wall 213. Arranging the third connecting portion 2621 perpendicular to the fourth connecting portion 2622 facilitates electrical connection between the second electrode terminal 232 and the second tab 2222 while reducing the space occupied by the second connecting member 262 within the battery cell 20.

[0107] It should be understood that the assembly order of the battery cells 20 of the present embodiment can be flexibly arranged according to actual applications. For example, the electrode assembly 22 can be first placed in the housing 214 through any opening of the housing 214. The first electrode terminal 231 provided on the first cover plate 215 is then electrically connected to the first electrode tab 2221. The first cover plate 215 is then closed over the first opening 2141, thereby connecting the first cover plate 215 to the housing 214. The second electrode terminal 232 provided on the second cover plate 216 is then electrically connected to the second electrode tab 2222. The second cover plate 216 is then closed over the second opening 2142, thereby connecting the second cover plate 216 to the housing 214.

[0108] In some embodiments, in contrast to the above-described installation method, other methods may be used to assemble the battery cell 20. FIG7 shows a schematic diagram of a partial structure of a battery cell 20 according to an embodiment of the present application. For example, FIG7 shows a schematic diagram of the unfolded structure of the electrode assembly 22, the first connecting member 261, the second connecting member 262, the first cover plate 215, and the second cover plate 216 included in the battery cell 20 as shown in FIG3 to FIG5. As shown in FIG3 to FIG7, the relative fixation between the first electrode terminal 231 and the first electrode tab 2221 provided on the first cover plate 215 can be achieved. Similarly, the relative fixation between the second electrode terminal 232 and the second electrode tab 2222 provided on the second cover plate 216 can be achieved. In this way, the electrode assembly 22, the first cover plate 215 and the second cover plate 216 can be passed through any opening of the shell 214 to accommodate the electrode assembly 22 in the shell 214, and then the first cover plate 215 and the second cover plate 216 are respectively connected to the shell 214 to complete the assembly of the battery cell 20.

[0109] In some embodiments, for different assembly methods, to improve the installation efficiency of the battery cell 20, the first connecting member 261 and the second connecting member 262 can be connected first and then bent. Specifically, taking Figure 7 as an example, before connection, the first connecting member 261 can be approximately a flat plate-shaped structure, and the first connecting portion 2611 of the first connecting member 261 is electrically connected to the first electrode tab 2221, and the second connecting portion 2612 of the first connecting member 261 is electrically connected to the first electrode terminal 231. Afterwards, the first connecting member 261 is bent. For example, taking Figures 5 and 6 as examples, after bending, the first electrode tab 2221 and the first electrode terminal 231 can be oriented toward different sides of the battery cell 20. Similarly, before connection, the second connecting member 262 can also be approximately a flat plate structure, and the third connecting portion 2621 of the second connecting member 262 is electrically connected to the second pole ear 2222, and the fourth connecting portion 2622 of the second connecting member 262 is electrically connected to the second electrode terminal 232; thereafter, the second connecting member 262 is bent to realize that the second pole ear 2222 and the second electrode terminal 232 are facing different sides of the battery cell 20.

[0110] In some embodiments, the battery cell 20 may further include an insulating layer 25 , which is used to wrap at least a portion of the electrode assembly 22 to isolate the electrode assembly 22 from the inner surface of the shell 214 , thereby improving the reliability of the battery cell 20 .

[0111] The electrode assembly 22 of the embodiment of the present application will be described below with reference to the accompanying drawings.

[0112] The battery cell 20 of the embodiment of the present application may include one or more electrode assemblies 22. The electrode assembly 22 is the component where the electrochemical reaction occurs in the battery cell 20. The electrode assembly 22 may include a positive electrode sheet, a negative electrode sheet, and a separator, which is used to separate the positive electrode sheet from the negative electrode sheet.

[0113] In some embodiments, the positive electrode sheet 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.

[0114] As an example, the positive electrode current collector has two surfaces facing each other in its thickness direction, and the positive electrode active material is provided on either or both of the two facing surfaces of the positive electrode current collector.

[0115] As an example, the positive electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0116] As an example, the positive electrode active material may include at least one of the following materials: lithium-containing phosphates, lithium transition metal oxides, and their respective modified compounds. However, the present application is not limited to these materials, and other traditional 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-containing phosphates may include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), a composite material of lithium iron phosphate and carbon, lithium manganese phosphate (such as LiMnPO4), a composite material of lithium manganese phosphate and carbon, lithium iron manganese phosphate, and a composite material of lithium iron manganese phosphate and carbon.

[0117] In some embodiments, the negative electrode sheet may include a negative current collector.

[0118] As an example, the negative electrode current collector may be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel with a silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. may be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector may be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0119] As an example, the negative electrode sheet may further include a negative electrode active material disposed on at least one surface of a negative electrode current collector.

[0120] As an example, the negative electrode current collector has two surfaces facing each other in its thickness direction, and the negative electrode active material is provided on either or both of the two facing surfaces of the negative electrode current collector.

[0121] As an example, the negative electrode active material may be a negative electrode active material known in the art for battery cells 20. 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.

[0122] In some embodiments, the negative electrode may be a metal foam. The metal foam may be nickel foam, copper foam, aluminum foam, alloy foam, or carbon foam. When the metal foam is used as the negative electrode, the surface of the metal foam may or may not be provided with a negative electrode active material.

[0123] As an example, the negative electrode current collector may be filled with or / and deposited with a lithium source material, potassium metal, or sodium metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0124] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0125] In some embodiments, the electrode assembly 22 of the embodiment of the present application may include a tab 222 and a main body 221, wherein the tab 222 of the electrode assembly 22 may include a positive tab and a negative tab, the positive tab is connected to the positive electrode sheet of the main body 221, for example, the positive tab may be formed by a portion of the positive electrode current collector that is not coated with the positive electrode active material layer, and protrudes from the positive electrode sheet; similarly, the negative tab is connected to the negative electrode sheet of the main body 221, for example, the negative tab may be formed by a portion of the negative electrode current collector that is not coated with the negative electrode active material layer, and protrudes from the negative electrode sheet; the main body 221 is the portion of the electrode assembly 22 where active ions (such as lithium ions) are embedded and released back and forth between the positive electrode sheet and the positive electrode sheet.

[0126] In some embodiments, the electrode assembly 22 further includes a separator disposed between the positive electrode and the negative electrode.

[0127] In some embodiments, the separator is a separator. The present application has no particular limitation on the type of separator, and any known separator with a porous structure having good chemical and mechanical stability can be selected.

[0128] As an example, the main material of the isolation membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0129] In some embodiments, the separator is a solid electrolyte, which is disposed between the positive electrode and the negative electrode and serves to transport ions and isolate the positive and negative electrodes.

[0130] In some embodiments, the battery cell 20 further includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not specifically limit the type of electrolyte, and the electrolyte may be selected based on needs. The electrolyte may be liquid, gel, or solid.

[0131] In some embodiments, the electrode assembly 22 may be a wound structure or a laminated structure. This will be described below with reference to the accompanying drawings. Furthermore, for ease of explanation, the electrode assembly 22 is taken as an example, comprising a first electrode sheet 2211 and a second electrode sheet 2212 of opposite polarity. For example, if the first electrode sheet 2211 is a positive electrode sheet, the second electrode sheet 2212 is a negative electrode sheet; or, if the first electrode sheet 2211 is a negative electrode sheet, the second electrode sheet 2212 is a positive electrode sheet. Furthermore, the electrode assembly 22 may further include an isolating member 2213 for isolating the first electrode sheet 2211 from the second electrode sheet 2212.

[0132] Figures 8 and 9 illustrate schematic structural diagrams of a wound electrode assembly 22 according to an embodiment of the present application. For example, Figure 8 may be a schematic diagram of the electrode assembly 22 after winding, and Figure 9 may be a schematic diagram of the electrode assembly 22 when partially unfolded. Figures 8 and 9 take the example of a first electrode sheet 2211 being a positive electrode sheet and a second electrode sheet 2212 being a negative electrode sheet, but the embodiments of the present application are not limited thereto.

[0133] In some embodiments, the electrode assembly 22 includes a first electrode sheet 2211 and a second electrode sheet 2212 of opposite polarity. The first electrode sheet 2211 is connected to the first electrode tab 2221, and the second electrode sheet 2212 is connected to the second electrode tab 2222. The first electrode sheet 2211 and the second electrode sheet 2212 are wound along a winding axis, which is perpendicular to the first end surface 223. As shown in Figures 8 and 9, the wound electrode assembly 22 is simple to manufacture, which can improve the processing efficiency of the battery cell 20.

[0134] Figures 10 to 12 are schematic diagrams of the structure of a stacked electrode assembly 22 according to an embodiment of the present application. For example, Figures 10 and 11 may be partial expanded schematic diagrams of the electrode assembly 22 at different angles, and Figure 12 may be a schematic diagram of the structure of the stacked electrode assembly 22. Figures 10 to 12 still use the example of the first electrode sheet 2211 being the positive electrode sheet and the second electrode sheet 2212 being the negative electrode sheet, but the embodiments of the present application are not limited thereto.

[0135] In some embodiments, the electrode assembly 22 includes multiple first electrode sheets 2211 and multiple second electrode sheets 2212, the first electrode sheets 2211 and the second electrode sheets 2212 have opposite polarities, the first electrode sheet 2211 is connected to the first electrode ear 2221, and the second electrode sheet 2212 is connected to the second electrode ear 2222. The multiple first electrode sheets 2211 and the multiple second electrode sheets 2212 are alternately stacked along the stacking direction, and the stacking direction is parallel to the first end face 223. For example, the stacking direction in the figure is taken as the thickness direction Y of the electrode assembly 22 as an example.

[0136] In some embodiments, the stacked electrode assembly 22 may also adopt other structures. For example, the electrode assembly 22 includes a first electrode piece 2211 and a plurality of second electrode pieces 2212, wherein the first electrode piece 2211 and the second electrode piece 2212 have opposite polarities, the first electrode piece 2211 is connected to the first electrode tab 2221, and the second electrode piece 2212 is connected to the second electrode tab 2222. The first electrode piece 2211 includes a plurality of stacked segments and at least one bent segment, wherein the bent segment is used to connect two adjacent stacked segments. The plurality of stacked segments and the plurality of second electrode pieces 2212 are alternately stacked along a stacking direction, and the stacking direction is parallel to the first end face 223. For example, in the figure, the stacking direction is taken as the thickness direction Y of the electrode assembly 22 as an example. Furthermore, a plurality of positive electrode pieces are generally provided, and the negative electrode piece is folded to form a plurality of stacked folded segments, with a positive electrode piece sandwiched between adjacent folded segments to reduce metal precipitation, such as lithium or sodium precipitation, thereby improving the stability and service life of the electrode assembly 22.

[0137] In some embodiments, the stacked electrode assembly 22 may also be a stacked arrangement of multiple folded segments formed by folding both the positive electrode sheet and the negative electrode sheet, but the embodiments of the present application are not limited thereto.

[0138] The stacked electrode assembly 22 is simple to manufacture and can fully utilize the internal space of the battery cell 20 , thereby improving space utilization and further increasing the energy density of the battery cell 20 .

[0139] It should be understood that for the above-mentioned different types of electrode assemblies 22, multiple separators 2213 can be provided, each of which is disposed between any adjacent positive electrode sheets or negative electrode sheets. Alternatively, the separator 2213 can also be provided continuously, and disposed between any adjacent positive electrode sheets or negative electrode sheets by folding or winding. The embodiments of the present application are not limited to this.

[0140] In the embodiment of the present application, the arrangement of the tabs 222 of the electrode assembly 22 can be set according to the actual application. For example, as shown in Figures 7 to 9, the first tab 2221 of the electrode assembly 22 can be formed by stacking multiple layers of tabs connected to the first electrode sheet 2211, and the first tab 2221 is bent and electrically connected to the first connection portion 2611 of the first connection member 261. Furthermore, if multiple electrode assemblies 22 are provided in the battery cell 20, the multiple first tabs 2221 corresponding to the multiple electrode assemblies 22 can be stacked with the first connection portion 2611, for example, they can be stacked with each other in a direction perpendicular to the first end face 223 to save space. Similarly, the second tab 2222 of the electrode assembly 22 can be formed by stacking multiple layers of tabs connected to the second electrode sheet 2212, and the second tab 2222 is bent and electrically connected to the third connection portion 2621 of the second connection member 262. Furthermore, if multiple electrode assemblies 22 are provided in the battery cell 20, the multiple second tabs 2222 corresponding to the multiple electrode assemblies 22 can be stacked with the third connecting portion 2621, for example, they can be stacked in a direction perpendicular to the first end face 223 to save space.

[0141] In some embodiments, the tabs 222 may be provided in other ways. FIG13 shows a schematic structural diagram of the electrode assembly 22 of an embodiment of the present application, where a stacked electrode assembly 22 is taken as an example, but the embodiments of the present application are not limited thereto. As shown in FIG12 and FIG13 , the first tab 2221 of the electrode assembly 22 may be formed by stacking multiple layers of tabs connected to the first electrode sheet 2211, and the first tab 2221 of the multi-layer structure may be squeezed to one side of the first end face 223 to save space. Similarly, the second tab 2222 of the multi-layer structure may also be squeezed to one side of the first end face 223 to save space.

[0142] FIG14 is a schematic diagram illustrating the structure of multiple electrode assemblies 22 according to an embodiment of the present application, with two electrode assemblies 22 being used as an example. As shown in FIG14 , if multiple electrode assemblies 22 are disposed within a battery cell 20, the first tabs 2221 of any two adjacent electrode assemblies 22 can be disposed close to each other, and correspondingly, the second tabs 2222 of the two adjacent electrode assemblies 22 can also be disposed close to each other.

[0143] FIG15 shows another schematic diagram of the structure of multiple electrode assemblies 22 according to an embodiment of the present application, and FIG16 shows a schematic diagram of the structure of two connecting members and multiple electrode assemblies 22 according to an embodiment of the present application. As shown in FIG15 and FIG16 , for any two adjacent electrode assemblies 22, the first tabs 2221 of the two electrode assemblies 22 can be bent in opposite directions so that the first tabs 2221 of the two electrode assemblies 22 are approximately at the same height; similarly, the second tabs 2222 of the two electrode assemblies 22 can be bent in opposite directions so that the second tabs 2222 of the two electrode assemblies 22 are also approximately at the same height. The first connection portion 2611 of the first connection member 261 is electrically connected to the first pole lugs 2221 of the two electrode assemblies 22 at the same time, and the third connection portion 2621 of the second connection member 262 is electrically connected to the second pole lugs 2222 of the two electrode assemblies 22 at the same time. This can increase the area of ​​the connection region between the first connection portion 2611 and each first pole lug 2221, and can also increase the area of ​​the connection region between the third connection portion 2621 and each second pole lug 2222, thereby improving the structural stability of the battery cell 20; it can also reduce the total thickness of the pole lug 222 and the corresponding connection member, thereby improving the space utilization inside the battery cell 20, and improving the energy density of the battery cell 20.

[0144] In some embodiments, the shape, size, and other parameters of the first connecting member 261 and the second connecting member 262 can be configured based on the actual application. For example, the first connecting member 261 and the second connecting member 262 can have the same structure to facilitate processing. For another example, the shape, size, and other parameters of the first connecting portion 2611 and the second connecting portion 2612 of the first connecting member 261 can be the same or different to accommodate different application scenarios. Similarly, the shape, size, and other parameters of the third connecting portion 2621 and the fourth connecting portion 2622 of the second connecting member 262 can be the same or different to accommodate different application scenarios.

[0145] Figure 17 shows a schematic diagram of the structure of the first wall 211 or the second wall 212 of an embodiment of the present application, and Figure 18 shows a schematic front view of the first wall 211 or the second wall 212 of an embodiment of the present application. That is, Figures 17 and 18 can be used to represent the first wall 211 of the embodiment of the present application, or can also be used to represent the second wall 212. For example, the first wall 211 can be the first cover plate 215 of the battery cell 20, and the second wall 212 can be the second cover plate 216 of the battery cell 20. In some embodiments, the second wall 212 of the embodiment of the present application can adopt the same structure as the first wall 211, but the embodiment of the present application is not limited to this.

[0146] In some embodiments, the first wall 211 is provided with a first groove 2111 that is recessed toward the interior of the battery cell; and / or the second wall 212 is provided with a second groove 2121 that is recessed toward the interior of the battery cell. The first end surface 223 of the electrode assembly 22 is provided with a first tab 2221 and a second tab 2222. For example, if the first end surface 223 is perpendicular to the height direction Z of the electrode assembly 22, during use of the battery cell 20, the electrode assembly 22 will expand, typically in a direction perpendicular to the height direction Z of the electrode assembly 22. For example, the electrode assembly 22 typically expands more significantly in the thickness direction Y. The first wall 211 is connected to the third wall 213. If the first groove 2111 is provided on the first wall 211, if the electrode assembly 22 expands, the first groove 2111 on the first wall 211 provides a deformation margin for tensile deformation of the first wall 211, thereby reducing the risk of cracking between the first wall 211 and other connected walls. For example, if the first wall 211 is the first cover plate 215, this can reduce the risk of cracking in the connection area between the first cover plate 215 and the housing 214. Similarly, the second wall 212 is connected to the third wall 213. When a second groove 2121 is provided in the second wall 212, if the electrode assembly 22 expands, the second groove 2121 can provide deformation margin for the second wall 212 to undergo tensile deformation, thereby reducing the risk of cracking between the second wall 212 and other connected walls.

[0147] In some embodiments, the shape, depth, and position of the first and second grooves 2111, 2121 can be customized based on the application. For example, the first groove 2111 can be an annular groove surrounding the edge of the first wall 211; and / or the second groove 2121 can be an annular groove surrounding the edge of the second wall 212. This facilitates processing and evenly distributes deformation of the first and second walls 211, 212, providing a margin for tensile deformation in all directions of the first and second walls 211, 212, and thus improving structural stability.

[0148] In the embodiment of the present application, the battery cell 20 further includes an insulating component 27 disposed between the first end surface 223 and the third wall 213. The insulating component 27 serves to both electrically insulate the tab 222 from the third wall 213 and support the third wall 213. In some embodiments, the insulating component 27 may be located between the tab 222 and the third wall 213; further, the insulating component 27 may be attached to the lower surface of the third wall 213 to support the third wall 213.

[0149] FIG19 is a schematic diagram illustrating the structure of an insulating component 27 according to an embodiment of the present application. For example, the insulating component 27 shown in FIG19 may be the insulating component 27 of the battery cell 20 shown in FIG5 . As shown in FIG19 , the insulating component 27 may be a substantially plate-shaped structure to save space and improve the space utilization and energy density of the battery cell 20.

[0150] In some embodiments, the insulating component 27 is provided with a pressure relief hole 271 , which is used to avoid the pressure relief mechanism 24 so as to be actuated in time when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold, thereby timely releasing the internal pressure or temperature of the battery cell 20 .

[0151] It should be understood that the shape and size of the pressure relief hole 271 in the embodiment of the present application can be set according to the actual application. In some embodiments, the shape of the pressure relief hole 271 can be set according to the shape of the pressure relief mechanism 24. For example, the shape of the pressure relief mechanism 24 is usually set to be the same as the shape of the pressure relief hole 271 to facilitate processing. In some embodiments, the area of ​​the pressure relief hole 271 can be set according to the area of ​​the pressure relief mechanism 24. For example, for any plane perpendicular to the height direction Z of the battery cell 20, the area of ​​the orthographic projection of the pressure relief hole 271 is usually slightly larger than the area of ​​the orthographic projection of the pressure relief mechanism 24 to reduce the impact of the insulating component 27 on the actuation of the pressure relief mechanism 24.

[0152] According to some embodiments of the present application, the present application also provides a battery, comprising the battery cell described in any of the above solutions.

[0153] According to some embodiments of the present application, the present application further provides an electrical device, comprising the battery described in any of the above schemes, and the battery is used to provide electrical energy to the electrical device.

[0154] The power-consuming device may be any of the aforementioned devices or systems using batteries.

[0155] According to some embodiments of the present application, referring to Figures 3 to 6, the present application provides a battery cell 20, including: a plurality of walls, the plurality of walls including a first wall 211, a second wall 212 and a third wall 213, the first wall 211 and the second wall 212 are arranged opposite to each other, and the third wall 213 is used to connect the first wall 211 and the second wall 212; an electrode assembly 22, a first end face 223 of the electrode assembly 22 is provided with a first pole ear 2221 and a second pole ear 2222 with opposite polarities, the first end face 223 is the end face of the electrode assembly 22 facing the third wall 213; a first electrode terminal 231, provided on the first wall 211, the first electrode terminal 231 is used to be electrically connected to the first pole ear 2221; a second electrode terminal 232, provided on the second wall 212, the second electrode terminal 232 is used to be electrically connected to the second pole ear 2222; a pressure relief mechanism 24, provided on the third wall 213. The battery cell 20 further includes: a housing 214 for accommodating the electrode assembly 22, the housing 214 having a first opening 2141 and a second opening 2142 oppositely disposed, the third wall 213 being a wall of the housing 214; a first cover plate 215 for covering the first opening 2141, the first cover plate 215 being the first wall 211; and a second cover plate 216 for covering the second opening 2142, the second cover plate 216 being the second wall 212. The first wall 211 is provided with a first groove 2111 recessed toward the interior of the battery cell; the second wall 212 is provided with a second groove 2121 recessed toward the interior of the battery cell.

[0156] The battery cell 20 also includes: a first connecting member 261, which is used to connect the first pole tab 2221 and the first electrode terminal 231, and the first connecting member 261 includes a relatively bent first connecting portion 2611 and a second connecting portion 2612, the first connecting portion 2611 is used to electrically connect to the first pole tab 2221, and the second connecting portion 2612 is used to electrically connect to the first electrode terminal 231; a second connecting member 262, which is used to connect the second pole tab 2222 and the second electrode terminal 232, and the second connecting member 262 includes a relatively bent third connecting portion 2621 and a fourth connecting portion 2622, the third connecting portion 2621 is used to electrically connect to the second pole tab 2222, and the fourth connecting portion 2622 is used to electrically connect to the second electrode terminal 232.

[0157] The battery cell 20 further includes an insulating component 27 disposed between the first end surface 223 and the third wall 213 . The insulating component 27 is provided with a pressure relief hole 271 , which is used to avoid the pressure relief mechanism 24 .

[0158] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that, Comprising: A plurality of walls, said plurality of walls including a first wall (211), a second wall (212) and a third wall (213), the first wall (211) and the second wall (212) being oppositely arranged, and the third wall (213) being used for connecting the first wall (211) and the second wall (212); An electrode assembly (22), a first end face (223) of the electrode assembly (22) being provided with a first tab (2221) and a second tab (2222) with opposite polarities, and the first end face (223) being the end face of the electrode assembly (22) facing the third wall (213); A first electrode terminal (231), arranged on the first wall (211), and the first electrode terminal (231) being used for electrically connecting with the first tab (2221); A second electrode terminal (232), arranged on the second wall (212), and the second electrode terminal (232) being used for electrically connecting with the second tab (2222); A pressure relief mechanism (24), arranged on the third wall (213).

2. The battery cell according to claim 1, characterized in that, The battery cell further comprises: A housing (214), the housing (214) being used for accommodating the electrode assembly (22), the housing (214) having a first opening (2141) and a second opening (2142) arranged oppositely, and the third wall (213) being a wall of the housing (214); A first cover plate (215), the first cover plate (215) being used for covering the first opening (2141), and the first cover plate (215) being the first wall (211); A second cover plate (216), the second cover plate (y216) being used for covering the second opening (2142), and the second cover plate (216) being the second wall (212).

3. The battery cell according to claim 1 or 2, characterized in that, The battery cell further comprises: A first connection member (261), the first connection member (261) being used for connecting the first tab (2221) and the first electrode terminal (231), the first connection member (261) including a first connection portion (2611) and a second connection portion (2612) which are bent relatively, the first connection portion (2611) being used for electrically connecting with the first tab (2221), and the second connection portion (2612) being used for electrically connecting with the first electrode terminal (231); A second connection member (262), the second connection member (262) being used for connecting the second tab (2222) and the second electrode terminal (232), the second connection member (262) including a third connection portion (2621) and a fourth connection portion (2622) which are bent relatively, the third connection portion (2621) being used for electrically connecting with the second tab (2222), and the fourth connection portion (2622) being used for electrically connecting with the second electrode terminal (232).

4. The battery cell according to claim 3, characterized in that, The first connection member (261) is an integrally formed structure; and / or, The second connection member (262) is an integrally formed structure.

5. The battery cell according to claim 3 or 4, characterized in that, The first connection portion (2611) is perpendicular to the second connection portion (2612); and / or, The third connecting portion (2621) is perpendicular to the fourth connecting portion (2622).

6. The battery cell according to any one of claims 1 to 5, characterized in that, The first wall (211) is provided with a first groove (2111) that is recessed toward the inside of the battery cell. The second wall (212) is provided with a second groove (2121) that is recessed toward the inside of the battery cell.

7. The battery cell according to claim 6, wherein, The first groove (2111) is an annular groove and surrounds the edge region of the first wall (211); and / or, The second groove (2121) is an annular groove and surrounds the edge region of the second wall (212).

8. The battery cell according to any one of claims 1 to 7, characterized in that, The battery cell further includes: An insulating member (27), the insulating member (27) is disposed between the first end face (223) and the third wall (213).

9. The battery cell according to claim 8, wherein The insulating member (27) is provided with a pressure relief hole (271), and the pressure relief hole (271) is used to avoid the pressure relief mechanism (24).

10. The battery cell according to any one of claims 1 to 9, characterized in that, The electrode assembly (22) includes a first electrode tab (2211) and a second electrode tab (2212) with opposite polarities. The first electrode tab (2211) is connected to the first tab (2221), and the second electrode tab (2212) is connected to the second tab (2222). The first electrode tab (2211) and the second electrode tab (2212) are wound along a winding axis, and the winding axis is perpendicular to the first end face (223).

11. The battery cell according to any one of claims 1 to 9, characterized in that, The electrode assembly (22) includes a plurality of first electrode tabs (2211) and a plurality of second electrode tabs (2212). The first electrode tabs (2211) and the second electrode tabs (2212) have opposite polarities. The first electrode tab (2211) is connected to the first tab (2221), and the second electrode tab (2212) is connected to the second tab (2222). The plurality of first electrode tabs (2211) and the plurality of second electrode tabs (2212) are alternately stacked in a stacking direction, and the stacking direction is parallel to the first end face (223).

12. The battery cell according to any one of claims 1 to 9, characterized in that, The electrode assembly (22) includes a first electrode tab (2211) and a plurality of second electrode tabs (2212). The first electrode tab (2211) and the second electrode tabs (2212) have opposite polarities. The first electrode tab (2211) is connected to the first tab (2221), and the second electrode tab (2212) is connected to the second tab (2222). The first electrode tab (2211) includes a plurality of stacked segments and at least one bent segment. The bent segment is used to connect two adjacent stacked segments. The plurality of stacked segments and the plurality of second electrode tabs (2212) are alternately stacked in a stacking direction, and the stacking direction is parallel to the first end face (223).

13. A battery, characterized in that, Comprising: A plurality of battery cells, the battery cells being the battery cells according to any one of claims 1 to 12.

14. An electrical device, characterized in that, Comprising: A battery, the battery including the battery cells according to any one of claims 1 to 12, and the battery is used to supply power to the electrical device.

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