Battery monomer, battery and electric equipment

Abstract

The embodiment of the invention discloses a battery monomer, a battery and electric equipment. The battery cell includes: a plurality of walls including a first wall, a second wall, and a third wall, the first wall and the second wall being disposed opposite to each other, the third wall connecting the first wall and the second wall; the first end face of the electrode assembly is provided with a first tab and a second tab which are opposite in polarity, and the first end face is the end face, facing the third wall, of the electrode assembly; the first electrode terminal is arranged on the first wall, and the first electrode terminal is used for being electrically connected with the first tab; the second electrode terminal is arranged on the second wall, and the second electrode terminal is used for being electrically connected with the second tab; and the pressure relief mechanism is arranged on the third wall. According to the battery monomer, the battery and the electric equipment provided by the embodiment of the invention, the reliability of the battery can be improved.

Description

Technical Field

[0001] The present application relates to the field of batteries, and more specifically, to a battery cell, a battery, and an electrical device. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. In this context, electric vehicles have become an important part of the sustainable development of the automotive industry due to their advantages of energy conservation and environmental protection. For electric vehicles, battery technology is an important factor related to their development.

[0003] In the development of battery technology, in addition to improving the performance of batteries, safety issues are also problems that cannot be ignored. If the safety of the battery cannot be guaranteed, the battery cannot be used. Therefore, how to enhance the safety and reliability of batteries is an important technical issue in the development of battery technology. Summary of the Invention

[0004] Embodiments of the present application provide a battery cell, a battery, and an electrical device, which can improve the reliability of the battery.

[0005] In a first aspect, a battery cell is provided. The battery cell 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 disposed 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 tab and a second tab with opposite polarities, the first end face being the end face of the electrode assembly facing the third wall; a first electrode terminal disposed on the first wall, the first electrode terminal being used to electrically connect to the first tab; a second electrode terminal disposed on the second wall, the second electrode terminal being used to electrically connect to the second tab; and a pressure relief mechanism disposed on the third wall.

[0006] Therefore, for the battery cell of the embodiments of the present application, the two tabs of the electrode assembly are provided on the same end face, which can reduce the size of the electrode assembly in the direction perpendicular to the first end face, and further reduce the size of the battery cell in this direction. The two electrode terminals are respectively disposed on two opposite walls and correspond to different walls from the two tabs, which can further reduce the size of the battery cell in the direction perpendicular to the first end face, and thus improve the space utilization rate inside the battery cell. Further, the pressure relief mechanism and the two electrode terminals are 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 influence of the emissions discharged through the pressure relief mechanism on the two electrode terminals can be reduced, the risk of thermal diffusion inside the battery where the battery cell with thermal runaway is located can be reduced, and the risk of explosion of the battery can also be reduced, thereby improving the reliability of the battery.

[0007] In some embodiments, the battery cell further includes: a housing for accommodating the electrode assembly, the housing having a first opening and a second opening disposed opposite to each other, and the third wall being a wall of the housing; a first cover plate for covering the first opening, the first cover plate being the first wall; and a second cover plate for covering 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 housing through any one of the openings of the housing, and then the first cover plate is used to cover the first opening and the second cover plate is used to cover the second opening, so as to improve the processing efficiency. In addition, during the use of the battery cell, if the electrode assembly expands, the risk of connection failure between the housing and the two cover plates can be reduced, and the structural strength and stability of the battery cell can be improved.

[0008] In some embodiments, the battery cell further includes: a first connection member for connecting the first tab and the first electrode terminal, the first connection member including a first connection portion and a second connection portion that are bent relative to each other, the first connection portion being used for electrically connecting with the first tab, and the second connection portion being used for electrically connecting with the first electrode terminal; and a second connection member for connecting the second tab and the second electrode terminal, the second connection member including a third connection portion and a fourth connection portion that are bent relative to each other, the third connection portion being used for electrically connecting with the second tab, and the fourth connection portion being used for electrically connecting with the second electrode terminal. By means of the bent first connection member and second connection member, the first electrode terminal can be arranged on a different side from the first tab, and the second electrode terminal can be arranged on a different side from the second tab, with a simple structure and easy implementation.

[0009] In some embodiments, the first connection member is an integrally formed structure; and / or, the second connection member is an integrally formed structure. The connection steps between the first connection portion and the second connection portion can be saved; the connection steps between the third connection portion and the fourth connection portion can also be saved, the structures of the first connection member and / or the second connection member can be simplified, the assembly process of the battery cell can be simplified, and the installation efficiency of the battery cell can be improved.

[0010] 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 to save space.

[0011] In some embodiments, the first wall is provided with a first groove recessed towards the interior of the battery cell; and / or, the second wall is provided with a second groove recessed towards the interior of the battery cell. If the electrode assembly expands, the first groove in the first wall can provide a deformation margin for the first wall to undergo tensile deformation, 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, reducing the risk of cracking between the second wall and other connected walls.

[0012] In some embodiments, the first groove is an annular groove and surrounds the edge region of the first wall; and / or, the second groove is an annular groove and surrounds the edge region of the second wall. This is not only convenient for processing, but also enables the deformation of the first wall and the second wall to be evenly distributed, providing a deformation margin for the tensile deformation of the first wall and the second wall in all directions and enhancing the structural stability.

[0013] In some embodiments, the battery cell further includes: an insulating component disposed between the first end face and the third wall, which can be used to achieve electrical insulation between the tab and the third wall and also to support the third wall.

[0014] In some embodiments, the insulating component is provided with a pressure relief hole for avoiding 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, and then to release the internal pressure or temperature of the battery cell in time.

[0015] In some embodiments, the electrode assembly includes a first electrode tab and a second electrode tab with opposite polarities. The first electrode tab is connected to the first tab, the second electrode tab is connected to the second tab, and the first electrode tab and the second electrode tab are wound around a winding axis perpendicular to the first end face. The winding type electrode assembly has a simple processing process and can improve the processing efficiency of the battery cell.

[0016] In some embodiments, the electrode assembly includes a plurality of first electrode tabs and a plurality of second electrode tabs with opposite polarities. The first electrode tab is connected to the first tab, the second electrode tab is connected to the second tab, and the plurality of first electrode tabs and the plurality of second electrode tabs are alternately stacked in a stacking direction parallel to the first end face.

[0017] In some embodiments, the electrode assembly includes a first electrode tab and a plurality of second electrode tabs with opposite polarities. The first electrode tab is connected to the first tab, the second electrode tab is connected to the second tab. The first electrode tab includes a plurality of stacked segments and at least one bent segment for connecting two adjacent stacked segments, and the plurality of stacked segments and the plurality of second electrode tabs are alternately stacked in a stacking direction parallel to the first end face.

[0018] The processing method of the above-mentioned stacked electrode assembly is simple, and it can make full use of the internal space of the battery cell, improve the space utilization rate, and thus can improve the energy density of the battery cell.

[0019] In a second aspect, a battery is provided, including: a plurality of battery cells, where the battery cell is the battery cell described in the first aspect or any one of the embodiments in the first aspect.

[0020] In a third aspect, there is provided an electrical device, including: a battery, which includes the battery cell described in the first aspect or any one of the embodiments of the first aspect, and is used to supply power to the electrical device.

[0021] In some embodiments, the electrical device is a vehicle, a ship or a spacecraft. Description of the Drawings

[0022] Figure 1 Schematic diagram of a vehicle according to an embodiment of the present application;

[0023] Figure 2 Exploded structural schematic diagram of a battery according to an embodiment of the present application;

[0024] Figure 3 Structural schematic diagram of a battery cell according to an embodiment of the present application;

[0025] Figure 4 Front view schematic diagram of a battery cell according to an embodiment of the present application;

[0026] Figure 5 Exploded structural schematic diagram of a battery according to an embodiment of the present application;

[0027] Figure 6 Structural schematic diagram of an electrode assembly and a connection member according to an embodiment of the present application;

[0028] Figure 7 Expanded schematic diagram of a partial structure of a battery cell according to an embodiment of the present application;

[0029] Figure 8 Structural schematic diagram of a wound electrode assembly according to an embodiment of the present application;

[0030] Figure 9 Partially expanded structural schematic diagram of a wound electrode assembly according to an embodiment of the present application;

[0031] Figure 10 Partially expanded structural schematic diagram of a stacked electrode assembly according to an embodiment of the present application;

[0032] Figure 11 Top view schematic diagram of a partially expanded structure of a stacked electrode assembly according to an embodiment of the present application;

[0033] Figure 12 Structural schematic diagram of a stacked electrode assembly according to an embodiment of the present application;

[0034] Figure 13 Another structural schematic diagram of a stacked electrode assembly according to an embodiment of the present application;

[0035] Figure 14Schematic diagram of the structure of multiple stacked electrode assemblies according to an embodiment of the present application;

[0036] Figure 15 Another schematic diagram of the structure of multiple stacked electrode assemblies according to an embodiment of the present application;

[0037] Figure 16 Another schematic diagram of the structure of an electrode assembly and a connecting member according to an embodiment of the present application;

[0038] Figure 17 Schematic diagram of the structure of the first wall or the second wall according to an embodiment of the present application;

[0039] Figure 18 Front view schematic diagram of the structure of the first wall or the second wall according to an embodiment of the present application;

[0040] Figure 19 Schematic diagram of the structure of an insulating component according to an embodiment of the present application.

[0041] In the drawings, the drawings are not drawn to actual scale. Detailed implementation manners

[0042] Next, the technical solutions in the embodiments of the present application will be described with reference to the drawings.

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the drawings in the embodiments of the present application. Apparently, the described embodiments are some, but not all, of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present application.

[0044] Unless otherwise defined, all technical and scientific terms used in the present application have the same meaning as commonly understood by those skilled in the technical field to which the present application belongs; the terms used in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application; the terms "including" and "having" and any variations thereof in the specification and claims of the present application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the specification and claims of the present application or the above drawings are used to distinguish different objects and are not used to describe a specific order or primary-secondary relationship.

[0045] Reference to "embodiment" in this application means that the specific features, structures, or characteristics described in connection with the embodiment may be included in at least one embodiment of this application. The phrase appears in various places in the specification and does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in this application may be combined with other embodiments.

[0046] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected to", and "attached to" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] The term "and / or" in this application is merely a relational description of the associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0048] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are only illustrative and should not constitute any limitation to this application.

[0049] The term "a plurality of" appearing in this application refers to two or more (including two). Similarly, "a plurality of groups" refers to two or more groups (including two groups), and "a plurality of pieces" refers to two or more pieces (including two pieces).

[0050] In the embodiments of this application, the battery cell may be a secondary battery, which refers to a battery cell that can be activated by charging after discharging and can continue to be used.

[0051] The battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of this application are not limited thereto.

[0052] A battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of the battery cell, active ions (such as lithium ions) are intercalated and deintercalated back and forth between the positive electrode and the negative electrode. The separator is disposed between the positive electrode and the negative electrode, which can prevent short circuit between the positive and negative electrodes and allow active ions to pass through.

[0053] In some embodiments, the positive electrode may be a positive electrode plate, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

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

[0055] As an example, the negative electrode plate may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0056] In some embodiments, the battery cell further includes an electrolyte, which plays a role in conducting ions between the positive and negative electrodes. The present application does not specifically limit the type of the electrolyte, and it can be selected according to requirements. The electrolyte can be liquid, gel-like, or solid.

[0057] In some embodiments, the shape of the electrode assembly can be cylindrical, flat, or multi-prismatic, etc.

[0058] In some embodiments, the electrode assembly is provided with tabs, and the tabs can conduct current out of the electrode assembly. The tabs include a positive tab and a negative tab.

[0059] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as the electrode assembly and the electrolyte. The housing can be a steel shell, an aluminum shell, a plastic shell (such as polypropylene), a composite metal shell (such as a copper-aluminum composite shell), or an aluminum plastic film, etc. The housing includes a shell body and a cover plate.

[0060] 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, a multi-prismatic battery, and the multi-prismatic battery is, for example, a hexagonal-prismatic battery, etc. The present application has no special limitation.

[0061] 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, parallel, or in a hybrid connection through a busbar component.

[0062] In some embodiments, the battery can be a battery module. When there are multiple battery cells, the multiple battery cells are arranged and fixed to form a battery module.

[0063] In some embodiments, the battery may be a battery pack, which includes a case and battery cells, and the battery cells or battery modules are accommodated in the case.

[0064] In some embodiments, the case may be part of the chassis structure of a vehicle. For example, part of the case may form at least part of the floor of the vehicle, or part of the case may form at least part of the cross beams and longitudinal beams of the vehicle.

[0065] Currently, a battery cell generally includes a housing and an electrode assembly accommodated in the housing. The housing is a hollow structure with one end open. An electrolyte is filled in the housing, and the opening of the housing is covered by a cover plate. Usually, an electrode terminal and a pressure relief mechanism are provided on the cover plate. The electrode terminal is electrically connected to the tab of the electrode assembly to output the electrical energy of the battery cell. The pressure relief mechanism is used to actuate when the internal pressure or temperature of the battery cell reaches a predetermined threshold to release 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 will be discharged through the pressure relief mechanism. These emissions usually include conductive particles. The conductive particles splash to the electrode terminals around the pressure relief mechanism, which is very likely to cause a short circuit between the electrode terminals of different battery cells, and then trigger thermal diffusion or even explosion, seriously affecting the safety performance of the battery.

[0066] Therefore, the embodiments of the present application provide a battery cell, a battery and an electrical device, which can solve the above problems. The battery cell of the present application includes a plurality of walls, where 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 further includes an electrode assembly. The first tab and the second tab with opposite polarities of the electrode assembly 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. Setting the two tabs of the electrode assembly on the same end face can reduce the size of the electrode assembly in the direction perpendicular to the first end face, and further reduce the size of the battery cell in this direction.

[0067] The battery cell further includes a first electrode terminal and a second electrode terminal with opposite polarities. The first electrode terminal is arranged on the first wall and is used to be electrically connected to the first tab, and the second electrode terminal is arranged on the second wall and is used to be electrically connected to the second tab. Setting the two electrode terminals on two opposite walls respectively and corresponding to different walls from the two tabs can further reduce the size of the battery cell in the direction perpendicular to the first end face, and further improve the space utilization rate inside the battery.

[0068] In addition, the battery cell further includes a pressure relief mechanism disposed on the third wall. The pressure relief mechanism and the two electrode terminals are 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, the risk of thermal diffusion inside the battery where the battery cell with thermal runaway occurs can be reduced, the risk of explosion of the battery can also be reduced, and the reliability of the battery can be improved.

[0069] The technical solutions described in the embodiments of this application are applicable to various electrical equipment using batteries.

[0070] The electrical equipment can be vehicles, mobile phones, portable devices, laptop computers, ships, spacecraft, electric toys, and power tools, etc. The vehicle can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc.; the spacecraft includes airplanes, rockets, space shuttles, and spaceships, etc.; the electric toys include stationary or mobile electric toys, for example, game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc.; the power tools include metal cutting power tools, grinding power tools, assembly power tools, and railway power tools, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers, etc. The embodiments of this application do not impose special restrictions on the above electrical equipment.

[0071] For the convenience of description in the following embodiments, the electrical equipment is taken as an example of a vehicle.

[0072] For example, as Figure 1 shown, it is a schematic structural diagram of a vehicle 1 according to an embodiment of this application. The vehicle 1 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc. A motor 40, a controller 30, and a battery 10 can be disposed inside the vehicle 1. The controller 30 is used to control the power supply of the battery 10 to the motor 40. For example, the battery 10 can be disposed at the bottom, the front end, or the rear end of the vehicle 1. The battery 10 can be used for the power supply of the vehicle 1. For example, the battery 10 can be used as the operating power source of the vehicle 1 and used for the circuit system of the vehicle 1, for example, for the working power requirements during the start, navigation, and operation of the vehicle 1. In another embodiment of this application, the battery 10 can not only be used as the operating power source of the vehicle 1, but also be used as the driving power source of the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0073] For example. Figure 2 shows a partial schematic structural diagram of the battery 10 according to an embodiment of this application. As Figure 2As shown, 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 Figure 2 As shown, the battery 10 of the embodiment of the present application may further include a box body 11, and the box body 11 may 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, which are respectively referred to 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 snapped together. The shapes of the first box body part 111 and the second box body part 112 may be determined according to the shapes of the components accommodated inside, for example, may be determined according to the shape of the combination of a plurality of battery cells 20 accommodated inside.

[0074] It should be understood that at least one of the first box body part 111 and the second box body part 112 has an opening. For example, as Figure 2 As shown, the first box body part 111 and the second box body part 112 may both be hollow cuboids and each has a face as an opening face. The opening of the first box body part 111 and the opening of the second box body part 112 are oppositely arranged, and the first box body part 111 and the second box body part 112 are snapped together to form a box body 11 with a closed chamber, and this chamber may be used to accommodate a plurality of battery cells 20. A plurality of battery cells 20 are placed in parallel or in series or in a mixed connection combination in the box body 11 formed after the first box body part 111 and the second box body part 112 are snapped together.

[0075] For another example, different from Figure 2 As shown, only one of the first box body part 111 and the second box body part 112 may be a hollow cuboid with an opening, and the other may be plate-shaped to cover the opening. Taking the second box body part 112 as a hollow cuboid with an opening and the first box body part 111 as plate-shaped as an example, then the first box body part 111 covers the opening of the second box body part 112 to form a box body 11 with a closed chamber, and this chamber may be used to accommodate a plurality of battery cells 20.

[0076] In some embodiments, the battery 10 may further include a busbar component, and the busbar component may be used to achieve electrical connection between a plurality of battery cells 20, such as in parallel or in series or in a mixed connection. Specifically, the busbar component may achieve electrical connection between battery cells 20 by connecting the electrode terminals of the battery cells 20; or, the busbar component may also achieve electrical connection between 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 the housing of the battery cells 20, etc., so as to achieve electrical connection between battery cells 20. Further, 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, the sealing structure or the housing, etc. by welding. The embodiment of the present application is not limited thereto.

[0077] Figure 3 shows a schematic structural 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 can be Figure 3 the front view of the battery cell 20 shown; Figure 5 shows an exploded structural diagram of a battery cell 20 according to an embodiment of the present application. For example, Figure 5 can be as Figure 3 and Figure 4 the exploded structural diagram of the battery cell 20 shown.

[0078] As Figures 3 to 5 shown, the battery cell 20 according to an embodiment of the present application may include a plurality of walls. The plurality of walls include a first wall 211, a second wall 212, and a third wall 213. The first wall 211 and the second wall 212 are oppositely arranged, and the third wall 213 is used to connect the first wall 211 and the second wall 212. The battery cell 20 according to an embodiment of the present application may further include an electrode assembly 22. A first end face 223 of the electrode assembly 22 is provided with a first tab 2221 and a second tab 2222 with opposite polarities. The first end face 223 is the end face of the electrode assembly 22 facing the third wall 213. The battery cell 20 according to an embodiment of the present application may further 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 the first electrode terminal 231 is used to electrically connect to the first tab 2221; the second electrode terminal 232 is disposed on the second wall 212, and the second electrode terminal 232 is used to electrically connect to the second tab 2222. The battery cell 20 according to an embodiment of the present application may further include a pressure relief mechanism 24, and the pressure relief mechanism 24 is disposed on the third wall 213.

[0079] It should be understood that the battery cell 20 according to an embodiment of the present application includes a plurality of walls, and the plurality of walls can be used to form a polyhedral hollow structure to accommodate the electrode assembly 22. For example, the battery cell 20 of a cuboid is mainly taken as an example in the embodiments of the present application, but the embodiments of the present application are not limited thereto.

[0080] 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 opposite to each other, that is, the first wall 211 and the second wall 212 are not directly connected. For example, taking the cuboid battery cell 20 as an example, the first wall 211 and the second wall 212 can be any two opposite and parallel walls of the battery cell 20. The third wall 213 of the embodiment of the present application is used to connect the first wall 211 and the second wall 212. Among them, 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 cuboid battery cell 20 as an example, the third wall 213 can be the wall directly connected to the first wall 211 and the second wall 212.

[0081] It should be understood that the electrode assembly 22 of the embodiment of the present application may include a tab 222, and the tab 222 can conduct the current out of the electrode assembly 22. Specifically, the tab 222 of the electrode assembly 22 includes a first tab 2221 and a second tab 2222 with opposite polarities, and both of the two tabs 222 are located on the first end face 223 of the electrode assembly 22, that is, the two tabs 222 extend from the same side of the electrode assembly 22. Arranging the two tabs 222 of the electrode assembly 22 on the same end face can reduce the size of the electrode assembly 22 in the direction perpendicular to the first end face 223. For example, taking the height direction Z of the electrode assembly 22 perpendicular to the first end face 223 as an example, the size of the electrode assembly 22 in the height direction Z can be reduced, and further the size of the battery cell 20 in the height direction Z can be reduced.

[0082] In some embodiments, the first tab 2221 of the embodiment of the present application can be a positive tab, then the second tab 2222 is a negative tab; or, the first tab 2221 can be a negative tab, then the second tab 2222 is a positive tab. The embodiment of the present application is not limited thereto.

[0083] In some embodiments, the electrode assembly 22 may include at least one first tab 2221 and at least one second tab 2222. The embodiment of the present application mainly takes any one first tab 2221 and the corresponding one second tab 2222 of the electrode assembly 22 as an example. For example, as Figures 3 to 5 shown, the electrode assembly 22 may include one first tab 2221 and one second tab 2222, but the embodiment of the present application is not limited thereto.

[0084] It should be understood that the first electrode terminal 231 disposed on the first wall 211 in the embodiment of the present application is electrically connected to the first tab 2221, and the second electrode terminal 232 disposed on the second wall 212 is electrically connected to the second tab 2222. Since the two electrode terminals are located on different walls respectively, and the walls where these two electrode terminals are located are different from the walls corresponding to the tabs 222, the size of the battery cell 20 in the 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 rate inside the battery 10.

[0085] In the embodiment of the present application, the first electrode terminal 231 can be a positive electrode terminal, and the second electrode terminal 232 is a negative electrode terminal; or, the first electrode terminal 231 can be a negative electrode terminal, and the second electrode terminal 232 is a positive electrode terminal. The embodiment of the present application is not limited thereto.

[0086] In some embodiments, the battery cell 20 can include at least one first electrode terminal 231 and at least one second electrode terminal 232. The embodiment of the present application mainly takes any one first electrode terminal 231 and the corresponding one second electrode terminal 232 of the battery cell 20 as an example. For example, the battery cell 20 in the embodiment of the present application can include a plurality of first electrode terminals 231, and the plurality of first electrode terminals 231 can all be located on the first wall 211; the battery cell 20 in the embodiment of the present application can also include a plurality of second electrode terminals 232, and the plurality of second electrode terminals 232 can all be located on the second wall 212, but the embodiment of the present application is not limited thereto. As Figures 3 to 5 shown, here the battery cell 20 including one first electrode terminal 231 and one second electrode terminal 232 is taken as an example.

[0087] In the embodiment of the present application, the battery cell 20 further includes a pressure relief mechanism 24 disposed on the third wall 213. Since the pressure relief mechanism 24 and the two electrode terminals are located on different walls respectively, in this way, when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold and thermal runaway occurs, the influence of the emissions discharged through the pressure relief mechanism 24 on the two electrode terminals can be reduced, the risk of thermal diffusion inside the battery 10 caused by the battery cell 20 in thermal runaway can be reduced, and the risk of explosion of the battery 10 can also be reduced, thereby improving the reliability of the battery 10.

[0088] It should be understood that the pressure relief mechanism 24 in the embodiment of the present application refers to an element or component that is actuated when the internal pressure or temperature of the battery cell 20 reaches a predetermined threshold to release the internal pressure or temperature. This threshold design varies according to different design requirements. This threshold may depend on one or several of the materials of the positive electrode plate, negative electrode plate, electrolyte, and separator in the battery cell 20.

[0089] As used in this application, "actuation" refers to the movement or activation of the pressure relief mechanism 24 to a certain state, so that the internal pressure and temperature of the battery cell 20 can be released. The movement generated by the pressure relief mechanism 24 may include, but is not limited to: at least a part of the pressure relief mechanism 24 breaking, shattering, being 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 battery cell 20 can be depressurized and its temperature can be released under controlled pressure or temperature, thereby avoiding potential more serious accidents.

[0090] The emissions from the battery cell 20 mentioned in this application include, but are not limited to: electrolyte, dissolved or fragmented positive and negative electrode plates, fragments of the separator, high-temperature and high-pressure gases generated by the reaction, flames, etc.

[0091] In the embodiment of this application, the pressure relief mechanism 24 is disposed on the third wall 213 of the battery cell 20. The pressure relief mechanism 24 may be a part of the third wall 213 or a split structure with the third wall 213, and is fixed on the third wall 213 by means such as welding. The embodiment of this application is not limited to this. For example, when the pressure relief mechanism 24 is a part of the third wall 213, for example, the pressure relief mechanism 24 may be formed by making a notch on the third wall 213, and the thickness of the third wall 213 corresponding to the notch is less than the thickness of other regions of the pressure relief mechanism 24 except at the notch. The notch is the weakest position of the pressure relief mechanism 24. When the gas generated by the battery cell 20 is too much, causing the internal pressure to rise and reach the threshold value, or when the heat generated by the internal reaction of the battery cell 20 causes the internal temperature of the battery cell 20 to rise and reach the threshold value, the pressure relief mechanism 24 may rupture at the notch, resulting in the internal and external communication of the battery cell 20, and the gas pressure and temperature are released outward through the crack of the pressure relief mechanism 24, thereby avoiding the explosion of the battery cell 20.

[0092] For another example, the pressure relief mechanism 24 may also be a split structure with the third wall 213. The pressure relief mechanism 24 may be in the form of, for example, an explosion-proof valve, a gas 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 value, the pressure relief mechanism 24 performs an action or a weak structure provided in the pressure relief mechanism 24 is damaged, thereby forming an opening or channel for the release of the internal pressure or temperature.

[0093] It should be understood that the battery cell 20 of the embodiment of the present application 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 the housing 214 has a first opening 2141 and a second opening 2142 that are oppositely arranged; 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.

[0094] The material of the housing 214 of the embodiment of the present application can include various types, such as copper, iron, aluminum, steel, aluminum alloy, etc. The housing 214 can be in various shapes, such as a cylinder, a cuboid, etc. Exemplarily, as Figures 3 to 5 shown, the embodiment of the present application mainly takes the housing 214 as a cuboid as an example; Exemplarily, the housing 214 has two openings, namely a first opening 2141 and a second opening 2142, and these two openings are two opposite faces of the housing 214. This structure with openings at both ends facilitates the assembly of the internal electrode assembly 22. The electrode assembly 22 can enter the housing 214 through any one of the openings, which can improve the processing efficiency of the battery cell 20.

[0095] The first cover plate 215 of the embodiment of the present application is used to cover the first opening 2141 of the housing 214, and the second cover plate 216 is used to cover the second opening 2142 of the housing 214, so as to isolate 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 usually adopt the same material for easy processing. The material of each cover plate of the embodiment of the present application can also be various, such as copper, iron, aluminum, steel, aluminum alloy, etc., and the materials of the two cover plates can be the same as or different from the material of the housing 214.

[0096] It should be understood that the shape of each cover plate of the embodiment of the present application can be adapted to the shape of the housing 214. For example, as Figures 3 to 5 shown, when the housing 214 is a cuboid structure, the shapes of the first cover plate 215 and the second cover plate 216 can be the same. For example, they are both plate-like structures adapted to the housing 214; or, different from Figures 3 to 5 the embodiment shown, the shapes of the first cover plate 215 and the second cover plate 216 can also be hollow cuboid structures with one end open, so that after the two cover plates are covered with the housing 214, a cuboid battery cell 20 is formed, or the shapes of the first cover plate 215 and the second cover plate 216 can be different. The embodiment of the present application is not limited to this.

[0097] In some embodiments, the third wall 213 is the wall of the housing 214; the first cover plate 215 is the first wall 211; the second cover plate 216 is the second wall 212. When assembling the battery cell 20, the electrode assembly 22 can enter the interior of the housing 214 from any one of the openings of the housing 214, and then cover the first opening 2141 with the first cover plate 215 and cover the second opening 2142 with the second cover plate 216 to improve the processing efficiency. And, as Figures 3 to 5 shown, considering that the two tabs 222 of the electrode assembly 22 are located on the first end face 223, taking the first end face 223 perpendicular to the height direction Z of the electrode assembly 22 as an example. During the use of the battery cell 20, the electrode assembly 22 usually expands along its thickness direction. For example, taking the thickness direction of the electrode assembly 22 as the width direction Y of the electrode assembly 22, then during the charge and discharge process of the battery cell 20, the size of the electrode assembly 22 changes greatly along its width direction Y. The two openings of the housing 214 are oppositely arranged along the length direction X of the electrode assembly 22, so that the expansion of the electrode assembly 22 can be effectively restricted by the housing 214, and the size change of the battery cell 20 during use can be reduced. And, since the connection strength between the housing 214 and each cover plate is limited, compared with setting the two cover plates in other positions, when the third wall 213 is the wall of the housing 214; the first cover plate 215 is the first wall 211; the second cover plate 216 is the second wall 212, the risk of connection failure between the housing 214 and the two cover plates can be reduced, and the structural strength and stability of the battery cell 20 can be improved.

[0098] It should be understood that the first electrode terminal 231 and the first tab 2221 in the embodiments of the present application can be directly connected or indirectly connected; the second electrode terminal 232 and the second tab 2222 can also be directly connected or indirectly connected. Below, with reference to the drawings, mainly taking the indirect connection between the first electrode terminal 231 and the first tab 2221 and the indirect connection between the second electrode terminal 232 and the second tab 2222 as examples for description.

[0099] In the embodiments of the present application, the battery cell 20 further includes: a first connection member 261 and a second connection member 262, wherein the first connection member 261 is used to connect the first tab 2221 and the first electrode terminal 231, and the second connection member 262 is used to connect the second tab 2222 and the second electrode terminal 232. The structures of the first connection member 261 and the second connection member 262 in the embodiments of the present application can be set according to actual applications to realize the setting of the electrode terminals and the tabs on different sides.

[0100] Figure 6 shows a schematic structural diagram of the electrode assembly 22, the first connection member 261 and the second connection member 262 in the embodiments of the present application. For example, Figure 6The electrode assembly 22, the first connection member 261, and the second connection member 262 shown may be partial structures included in the battery cell 20 as shown in Figures 3 to 5 The battery cell 20 shown includes. As shown in Figure 5 and Figure 6 shown, the electrical connection between the electrode terminal and the corresponding tab can be achieved through the bent first connection member 261 and second connection member 262.

[0101] In some embodiments, the first connection member 261 includes a relatively bent first connection portion 2611 and a second connection portion 2612. The first connection portion 2611 is used for electrically connecting to the first tab 2221, and the second connection portion 2612 is used for electrically connecting to the first electrode terminal 231. The second connection member 262 includes a relatively bent third connection portion 2621 and a fourth connection portion 2622. The third connection portion 2621 is used for electrically connecting to the second tab 2222, and the fourth connection portion 2622 is used for electrically connecting to the second electrode terminal 232. Through the bent first connection member 261 and second connection member 262, the first electrode terminal 231 can be arranged on a different side from the first tab 2221, and the second electrode terminal 232 can be arranged on a different side from the second tab 2222. The structure is simple and easy to implement.

[0102] In some embodiments, the first connection member 261 is an integrally formed structure; and / or, the second connection member 262 is an integrally formed structure. Setting the first connection member 261 as an integrally formed structure can save the connection steps between the first connection portion 2611 and the second connection portion 2612; similarly, setting the second connection member 262 as an integrally formed structure can save the connection steps between the third connection portion 2621 and the fourth connection portion 2622, simplify the structure of the first connection member 261 and / or the second connection member 262, simplify the assembly process of the battery cell 20, and improve the installation efficiency of the battery cell 20.

[0103] In some embodiments, the first connection portion 2611 is perpendicular to the second connection portion 2612; and / or, the third connection portion 2621 is perpendicular to the fourth connection portion 2622. The right-angled first connection member 261 can save space. Especially when the first wall 211 is perpendicular to the third wall 213, setting the first connection portion 2611 perpendicular to the second connection portion 2612 not only facilitates the electrical connection between the first electrode terminal 231 and the first tab 2221, but also can reduce the space occupied by the first connection member 261 inside the battery cell 20. Similarly, the right-angled second connection member 262 can save space. Especially when the second wall 212 is perpendicular to the third wall 213, setting the third connection portion 2621 perpendicular to the fourth connection portion 2622 not only facilitates the electrical connection between the second electrode terminal 232 and the second tab 2222, but also can reduce the space occupied by the second connection member 262 inside the battery cell 20.

[0104] It should be understood that the assembly sequence of the battery cell 20 according to the embodiments of the present application can be flexibly set according to actual applications. For example, the electrode assembly 22 can be first accommodated in the housing 214 through any one of the openings of the housing 214; then, the first electrode terminal 231 provided on the first cover plate 215 is electrically connected to the first tab 2221, and the first cover plate 215 is covered on the first opening 2141 so that the first cover plate 215 is connected to the housing 214. The second electrode terminal 232 provided on the second cover plate 216 is electrically connected to the second tab 2222, and the second cover plate 216 is covered on the second opening 2142 so that the second cover plate 216 is connected to the housing 214.

[0105] In some embodiments, different from the above installation method, other methods can also be used to assemble the battery cell 20. Figure 7 The schematic diagram of the partial structure of the battery cell 20 according to the embodiments of the present application is shown. For example, the Figure 7 is shown as Figures 3 to 5 The 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 shown. As Figures 3 to 7 shown, the relative fixation of the first cover plate 215 and the electrode assembly 22 can be achieved through the electrical connection between the first electrode terminal 231 provided on the first cover plate 215 and the first tab 2221. Similarly, the relative fixation of the second cover plate 216 and the electrode assembly 22 is achieved through the electrical connection between the second electrode terminal 232 provided on the second cover plate 216 and the second tab 2222. In this way, the electrode assembly 22, the first cover plate 215, and the second cover plate 216 can be jointly passed through any one of the openings of the housing 214 to accommodate the electrode assembly 22 in the housing 214, and then the first cover plate 215 and the second cover plate 216 are respectively connected to the housing 214 to complete the assembly of the battery cell 20.

[0106] 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 structure. The first connecting portion 2611 of the first connecting member 261 is electrically connected to the first tab 2221, and the second connecting portion 2612 of the first connecting member 261 is electrically connected to the first electrode terminal 231; then, the first connecting member 261 is bent. For example, taking Figure 5 and Figure 6For example, after bending, the first tab 2221 and the first electrode terminal 231 can face different sides of the battery cell 20. Similarly, before connection, the second connecting member 262 can also be approximated as a flat plate-like structure. The third connecting portion 2621 of the second connecting member 262 is electrically connected to the second tab 2222, and the fourth connecting portion 2622 of the second connecting member 262 is electrically connected to the second electrode terminal 232. After that, the second connecting member 262 is bent to make the second tab 2222 and the second electrode terminal 232 face different sides of the battery cell 20.

[0107] In some embodiments, the battery cell 20 may further include an insulating layer 25, which is used to wrap at least part of the electrode assembly 22 to isolate the electrode assembly 22 from the inner surface of the housing 214, thereby improving the reliability of the battery cell 20.

[0108] Next, the electrode assembly 22 of the embodiments of the present application will be described with reference to the drawings.

[0109] The battery cell 20 of the embodiments of the present application may include one or more electrode assemblies 22. The electrode assembly 22 is a component in the battery cell 20 where an electrochemical reaction occurs. The electrode assembly 22 may include a positive electrode plate, a negative electrode plate, and a separator, and the separator is used to separate the positive electrode plate and the negative electrode plate.

[0110] In some embodiments, the positive electrode plate may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0111] As an example, the positive current collector has two surfaces opposite to each other in its own thickness direction, and the positive active material is disposed on any one or both of the two opposite surfaces of the positive current collector.

[0112] As an example, the positive current collector may be a metal foil or a composite current collector. For example, as a 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 (such as 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.).

[0113] 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 conventional materials that can be used as the positive electrode active material of the battery can also be used. These positive electrode active materials can be used alone or in combination of two or more. Among them, examples of the lithium-containing phosphate may include, but are not limited to, lithium iron phosphate (such as LiFePO4 (which can also be abbreviated 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 manganese iron phosphate, and a composite material of lithium manganese iron phosphate and carbon.

[0114] In some embodiments, the negative electrode sheet may include a negative electrode current collector.

[0115] As an example, the negative electrode current collector can be a metal foil or a composite current collector. For example, as the metal foil, aluminum or stainless steel with silver surface treatment, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, nickel or titanium, etc. can be used. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (such as 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.).

[0116] As an example, the negative electrode sheet may further include a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0117] As an example, the negative electrode current collector has two surfaces opposite to each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0118] As an example, the negative electrode active material can be the negative electrode active material known in the art for the battery cell 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, etc.

[0119] In some embodiments, the negative electrode can be a foam metal. The foam metal can be foam nickel, foam copper, foam aluminum, foam alloy, or foam carbon, etc. When the foam metal is used as the negative electrode sheet, the negative electrode active material may not be provided on the surface of the foam metal, and of course, the negative electrode active material can also be provided.

[0120] As an example, a lithium source material, potassium metal, or sodium metal can also be filled and / or deposited in the negative electrode current collector, and the lithium source material is lithium metal and / or lithium-rich material.

[0121] In some embodiments, the material of the positive current collector can be aluminum, and the material of the negative current collector can be copper.

[0122] In some embodiments, the electrode assembly 22 of the embodiments of the present application may include a tab 222 and a main body portion 221. Among them, 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 plate of the main body portion 221. For example, the positive tab may be formed by a portion of the positive current collector where the positive active material layer is not coated and protrudes from the positive electrode plate; similarly, the negative tab is connected to the negative electrode plate of the main body portion 221. For example, the negative tab may be formed by a portion of the negative current collector where the negative active material layer is not coated and protrudes from the negative electrode plate; the main body portion 221 is the portion of the electrode assembly 22 where active ions (such as lithium ions) are inserted and extracted back and forth between the positive electrode plate and the positive electrode plate.

[0123] In some embodiments, the electrode assembly 22 further includes a separator disposed between the positive electrode and the negative electrode.

[0124] In some embodiments, the separator is a separator film. The present application does not particularly limit the type of the separator film, and any publicly known porous structure separator film with good chemical stability and mechanical stability can be selected.

[0125] As an example, the main material of the separator film can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0126] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive electrode and the negative electrode, and simultaneously functions to transport ions and isolate the positive and negative electrodes.

[0127] In some embodiments, the battery cell 20 further includes an electrolyte, and the electrolyte functions to conduct ions between the positive and negative electrodes. The present application does not specifically limit the type of the electrolyte, and it can be selected according to requirements. The electrolyte can be liquid, gel-like, or solid.

[0128] In some embodiments, the electrode assembly 22 can be a wound structure or a stacked structure. This will be described below with reference to the drawings. In addition, for ease of description, an example is given where the electrode assembly 22 includes a first electrode plate 2211 and a second electrode plate 2212 with opposite polarities. For example, if the first electrode plate 2211 is a positive electrode plate, then the second electrode plate 2212 is a negative electrode plate; or, if the first electrode plate 2211 is a negative electrode plate, then the second electrode plate 2212 is a positive electrode plate. In addition, the electrode assembly 22 may further include a separator 2213 for isolating the first electrode plate 2211 and the second electrode plate 2212.

[0129] Figure 8 and Figure 9The structural schematic diagram of the wound electrode assembly 22 according to the embodiment of the present application is shown. For example, Figure 8 it may be a schematic diagram after the electrode assembly 22 is wound, Figure 9 and it may be a schematic diagram when the electrode assembly 22 is partially unfolded. Figure 8 And Figure 9 Taking the first pole piece 2211 as the positive pole piece and the second pole piece 2212 as the negative pole piece as an example, but the embodiment of the present application is not limited thereto.

[0130] In some embodiments, the electrode assembly 22 includes a first pole piece 2211 and a second pole piece 2212 with opposite polarities. The first pole piece 2211 is connected to the first pole tab 2221, and the second pole piece 2212 is connected to the second pole tab 2222. The first pole piece 2211 and the second pole piece 2212 are wound along the winding axis, and the winding axis is perpendicular to the first end face 223. As Figure 8 And Figure 9 shown, the processing process of the wound electrode assembly 22 is simple, which can improve the processing efficiency of the battery cell 20.

[0131] Figures 10 to 12 The structural schematic diagrams of the stacked electrode assembly 22 according to the embodiments of the present application are respectively shown. For example, Figure 10 And Figure 11 they may be partial unfolded schematic diagrams of the electrode assembly 22 at different angles, Figure 12 and they may be the structural schematic diagrams of the electrode assembly 22 after stacking. Figures 10 to 12 Still taking the first pole piece 2211 as the positive pole piece and the second pole piece 2212 as the negative pole piece as an example, but the embodiment of the present application is not limited thereto.

[0132] In some embodiments, the electrode assembly 22 includes a plurality of first pole pieces 2211 and a plurality of second pole pieces 2212. The first pole pieces 2211 and the second pole pieces 2212 have opposite polarities. The first pole piece 2211 is connected to the first pole tab 2221, and the second pole piece 2212 is connected to the second pole tab 2222. The plurality of first pole pieces 2211 and the plurality of second pole pieces 2212 are alternately stacked along the 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.

[0133] In some embodiments, the stacked electrode assembly 22 may also adopt other structures. For example, 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 a first current collector tab 2221, and the second electrode tabs 2212 are connected to second current collector tabs 2222. The first electrode tab 2211 includes a plurality of stacked segments and at least one bending segment. The bending 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 the 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. Further, usually a plurality of positive electrode tabs are provided, and the negative electrode tab is folded to form a plurality of stacked folding segments, and a positive electrode tab is clamped between adjacent folding segments to reduce the phenomenon of metal deposition, such as reducing the phenomenon of lithium deposition or sodium deposition, and improving the stability and service life of the electrode assembly 22.

[0134] In some embodiments, the stacked electrode assembly 22 may also be such that both the positive electrode tab and the negative electrode tab are folded to form a plurality of stacked folding segments, and the embodiments of the present application are not limited thereto.

[0135] The processing method of the stacked electrode assembly 22 is simple, and the internal space of the battery cell 20 can be fully utilized to improve the space utilization rate, and thus the energy density of the battery cell 20 can be improved.

[0136] It should be understood that for the above different types of electrode assemblies 22, a plurality of separators 2213 may be provided and respectively disposed between any adjacent positive electrode tabs or negative electrode tabs. Alternatively, the separator 2213 may also be continuously provided and disposed between any adjacent positive electrode tabs or negative electrode tabs by folding or winding, and the embodiments of the present application are not limited thereto.

[0137] In the embodiments of the present application, the setting manner of the current collector tabs 222 of the electrode assembly 22 can be set according to actual applications. For example, as Figures 7 to 9As shown, the first tab 2221 of the electrode assembly 22 can be formed by stacking multiple layers of tabs connected to the first electrode tab 2211. After bending the first tab 2221, it is electrically connected to the first connection portion 2611 of the first connection member 261. Further, if a plurality of electrode assemblies 22 are provided in the battery cell 20, the plurality of first tabs 2221 corresponding to the plurality of electrode assemblies 22 can be stacked on top of each other with the first connection portion 2611. For example, they can be stacked on top of 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 tab 2212. After bending the second tab 2222, it is electrically connected to the third connection portion 2621 of the second connection member 262. Further, if a plurality of electrode assemblies 22 are provided in the battery cell 20, the plurality of second tabs 2222 corresponding to the plurality of electrode assemblies 22 can be stacked on top of each other with the third connection portion 2621. For example, they can be stacked on top of each other in a direction perpendicular to the first end face 223 to save space.

[0138] In some embodiments, other methods can also be used to arrange the tabs 222. Figure 13 The structural schematic diagram of the electrode assembly 22 according to the embodiment of the present application is shown. Here, the stacked electrode assembly 22 is taken as an example, but the embodiment of the present application is not limited thereto. As Figure 12 and Figure 13 shown, the first tab 2221 of the electrode assembly 22 can be formed by stacking multiple layers of tabs connected to the first electrode tab 2211. The first tab 2221 with a multi-layer structure can be squeezed to one side of the first end face 223 to save space. Similarly, the second tab 2222 with a multi-layer structure can also be squeezed to one side of the first end face 223 to save space.

[0139] Figure 14 The structural schematic diagram of multiple electrode assemblies 22 according to the embodiment of the present application is shown. Here, two electrode assemblies 22 are taken as an example. As Figure 14 shown, if a plurality of electrode assemblies 22 are provided inside the battery cell 20, the first tabs 2221 of any two adjacent electrode assemblies 22 can be arranged close to each other. Correspondingly, the second tabs 2222 of the two adjacent electrode assemblies 22 can also be arranged close to each other.

[0140] Figure 15 The structural schematic diagram of another multiple electrode assemblies 22 according to the embodiment of the present application is shown. Figure 16 The structural schematic diagram of two connection members and multiple electrode assemblies 22 according to the embodiment of the present application is shown. As Figure 15 and Figure 16As shown, for any two adjacent electrode assemblies 22, the first tab 2221 of these 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 are 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 tabs 2221 of the two electrode assemblies 22 simultaneously, and the third connection portion 2621 of the second connection member 262 is electrically connected to the second tabs 2222 of the two electrode assemblies 22 simultaneously. This can increase the area of the connection region between the first connection portion 2611 and each first tab 2221, and can also increase the area of the connection region between the third connection portion 2621 and each second tab 2222, improving the structural stability of the battery cell 20; it can also reduce the total thickness of the tabs 222 and the corresponding connection members, thereby improving the space utilization rate inside the battery cell 20 and the energy density of the battery cell 20.

[0141] In some embodiments, parameters such as the shapes and sizes of the first connection member 261 and the second connection member 262 can be set according to actual applications. For example, the first connection member 261 and the second connection member 262 can adopt the same structure for ease of processing. For another example, parameters such as the shapes and sizes of the first connection portion 2611 and the second connection portion 2612 of the first connection member 261 can be the same or different to adapt to different application scenarios. Similarly, parameters such as the shapes and sizes of the third connection portion 2621 and the fourth connection portion 2622 of the second connection member 262 can be the same or different to adapt to different application scenarios.

[0142] Figure 17 The structural schematic diagram of the first wall 211 or the second wall 212 of the embodiment of the present application is shown. Figure 18 The front view schematic diagram of the first wall 211 or the second wall 212 of the embodiment of the present application is shown, that is Figure 17 and Figure 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 thereto.

[0143] In some embodiments, the first wall 211 is provided with a first groove 2111 that is recessed toward the inside of the battery cell; and / or, the second wall 212 is provided with a second groove 2121 that is recessed toward the inside of the battery cell. The first end face 223 of the electrode assembly 22 is provided with a first tab 2221 and a second tab 2222. Taking the first end face 223 being perpendicular to the height direction Z of the electrode assembly 22 as an example, during the use of the battery cell 20, the electrode assembly 22 will expand, and the expansion direction is usually perpendicular to the height direction Z of the electrode assembly 22. For example, the thickness direction Y of the electrode assembly 22 usually expands more significantly. The first wall 211 is connected to the third wall 213. In the case where the first wall 211 is provided with the first groove 2111, if the electrode assembly 22 expands, the first groove 2111 of the first wall 211 can provide a deformation margin for the first wall 211 to undergo tensile deformation, 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, it 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. In the case where the second wall 212 is provided with the second groove 2121, if the electrode assembly 22 expands, the second groove 2121 can provide a deformation margin for the second wall 212 to undergo tensile deformation, reducing the risk of cracking between the second wall 212 and other connected walls.

[0144] In some embodiments, parameters such as the shape, depth, and position of the first groove 2111 and the second groove 2121 can be set according to actual applications. For example, the first groove 2111 is an annular groove and surrounds the edge area of the first wall 211; and / or, the second groove 2121 is an annular groove and surrounds the edge area of the second wall 212. This is not only convenient for processing but also enables the deformation of the first wall 211 and the second wall 212 to be evenly distributed, providing a deformation margin for the tensile deformation of the first wall 211 and the second wall 212 in all directions and enhancing the structural stability.

[0145] In the embodiments of the present application, the battery cell 20 further includes: an insulating member 27. The insulating member 27 is disposed between the first end face 223 and the third wall 213, which can be used to achieve electrical insulation between the tab 222 and the third wall 213 and can also be used to support the third wall 213. In some embodiments, the insulating member 27 can be located between the tab 222 and the third wall 213; further, the insulating member 27 can be arranged to be attached to the lower surface of the third wall 213 to support the third wall 213.

[0146] Figure 19 The structural schematic diagram of the insulating member 27 in the embodiments of the present application is shown. For example, Figure 19 The shown insulating member 27 can be as Figure 5The insulating component 27 of the battery cell 20 shown. As Figure 19 shown, the insulating component 27 can be an approximately plate-like structure to save the occupied space and improve the space utilization rate and energy density of the battery cell 20.

[0147] In some embodiments, the insulating component 27 is provided with a pressure relief hole 271, and the pressure relief hole 271 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, and then release the internal pressure or temperature of the battery cell 20 in time.

[0148] It should be understood that the shape and size of the pressure relief hole 271 in the embodiments of the present application can be set according to actual applications. 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, usually, the shape of the pressure relief mechanism 24 is set to be the same as the shape of the pressure relief hole 271 for easy 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 influence of the insulating component 27 on the actuation of the pressure relief mechanism 24.

[0149] According to some embodiments of the present application, the present application also provides a battery including the battery cell described in any of the above solutions.

[0150] According to some embodiments of the present application, the present application also provides an electrical device including the battery described in any of the above solutions, and the battery is used to provide electrical energy for the electrical device.

[0151] The electrical device can be any of the foregoing devices or systems using the battery.

[0152] According to some embodiments of the present application, refer to Figures 3 to 6, this application provides a battery cell 20, comprising: 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 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 having opposite polarities, 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, 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, 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. The battery cell 20 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 216 being used for covering the second opening 2142, and the second cover plate 216 being the second wall 212. The first wall 211 is provided with a first groove 2111 recessed towards the interior of the battery cell; the second wall 212 is provided with a second groove 2121 recessed towards the interior of the battery cell.

[0153] The battery cell 20 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.

[0154] The battery cell 20 further comprises: an insulating member 27, the insulating member 27 being arranged between the first end face 223 and the third wall 213. The insulating member 27 is provided with a pressure relief hole 271, and the pressure relief hole 271 is used for avoiding the pressure relief mechanism 24.

[0155] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than limiting them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered within the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions falling 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) having 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), 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), 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, wherein 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) which are oppositely arranged, 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 (216) 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 connecting member (261), the first connecting member (261) being used for connecting the first tab (2221) and the first electrode terminal (231), the first connecting member (261) including a first connecting portion (2611) and a second connecting portion (2612) which are bent relatively, the first connecting portion (2611) being used for electrically connecting with the first tab (2221), and the second connecting portion (2612) being used for electrically connecting with the first electrode terminal (231); A second connecting member (262), the second connecting member (262) being used for connecting the second tab (2222) and the second electrode terminal (232), the second connecting member (262) including a third connecting portion (2621) and a fourth connecting portion (2622) which are bent relatively, the third connecting portion (2621) being used for electrically connecting with the second tab (2222), and the fourth connecting 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 connecting member (261) is an integrally formed structure; and / or, The second connecting member (262) is an integrally formed structure.

5. The battery cell according to claim 3 or 4, characterized in that, 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).

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) recessed toward the inside of the battery cell. The second wall (212) is provided with a second groove (2121) 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 pole piece (2211) and a second pole piece (2212) with opposite polarities. The first pole piece (2211) is connected to the first pole tab (2221), and the second pole piece (2212) is connected to the second pole tab (2222). The first pole piece (2211) and the second pole piece (2212) are wound around 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 pole pieces (2211) and a plurality of second pole pieces (2212). The first pole pieces (2211) and the second pole pieces (2212) have opposite polarities. The first pole piece (2211) is connected to the first pole tab (2221), and the second pole piece (2212) is connected to the second pole tab (2222). The plurality of first pole pieces (2211) and the plurality of second pole pieces (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 pole piece (2211) and a plurality of second pole pieces (2212). The first pole piece (2211) and the second pole pieces (2212) have opposite polarities. The first pole piece (2211) is connected to the first pole tab (2221), and the second pole piece (2212) is connected to the second pole tab (2222). The first pole piece (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 pole pieces (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.

Images