Battery monomer, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrolyte, an electrode assembly and an expandable part, and the shell comprises a first shell wall; the electrolyte is contained in the shell; the electrode assembly is arranged in the shell; the expandable part is contained in the shell, at least part of the expandable part is arranged between the first shell wall and the electrode assembly, the two opposite side surfaces of the expandable part abut against the first shell wall and the electrode assembly respectively, and the expandable part is configured to expand when encountering the electrolyte. The battery monomer provided by the embodiment of the utility model can improve the reliability.

Description

Technical Field

[0001] This application relates to the field of batteries, and particularly to a battery cell, a battery device, and an electrical device. Background Art

[0002] With the development of new energy technologies, batteries are increasingly widely used, such as in mobile phones, laptop computers, battery-powered vehicles, electric vehicles, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and electric tools.

[0003] The development of battery technologies needs to consider multiple design factors simultaneously. For example, how to improve the reliability of battery cells is an important research direction in the field of batteries. Summary of the Utility Model

[0004] This application provides a battery cell, a battery device, and an electrical device, which can improve the reliability of the battery cell.

[0005] In a first aspect, this application provides a battery cell, including a housing, an electrolyte, an electrode assembly, and an expandable member. The housing includes a first housing wall; the electrolyte is contained within the housing; the electrode assembly is disposed within the housing; the expandable member is contained within the housing, and at least a part of the expandable member is disposed between the first housing wall and the electrode assembly. The expandable member abuts against the first housing wall and the electrode assembly respectively, and the expandable member is configured to expand when encountering the electrolyte.

[0006] In the technical solution of the embodiments of this application, an electrode assembly and an electrolyte are disposed within the housing of the battery cell, and at least a part of the electrode assembly is immersed in the electrolyte. At the same time, an expandable member that can expand when encountering the electrolyte is further disposed between the first housing wall of the housing and the electrode assembly. The expandable member can expand until its two side surfaces respectively abut against the first housing wall and the electrode assembly to press the electrode assembly, thereby enabling the relative position between the electrode assembly and the housing to be stable, reducing the possibility of the electrode assembly shaking or colliding under external impacts and the like, and further improving the reliability of the battery cell. At the same time, the expandable member expands after encountering the electrolyte, which facilitates the assembly of the battery cell.

[0007] According to some embodiments in the embodiments of this application, the expandable member is adhesively connected to at least one of the first housing wall and the electrode assembly. The expandable member is directly adhesively connected to the first housing wall and / or the electrode assembly, saving the space required for additionally arranging fixing members and reducing costs.

[0008] According to some embodiments of the embodiments of the present application, the battery cell includes two first shell walls oppositely arranged in a first direction and two second shell walls oppositely arranged in a second direction. The first direction intersects the second direction, and the area of the second shell wall is larger than that of the first shell wall. The battery cell can be a square shell battery, and an expandable member is arranged in a direction where the electrode assembly is not easily expanded by itself, further reducing the possibility of the electrode assembly shaking.

[0009] According to some embodiments of the embodiments of the present application, at least a part of the expandable member is arranged between the second shell wall and the electrode assembly, and the opposite two side surfaces are respectively in contact with the second shell wall and the electrode assembly. An expandable member is also arranged between the second shell wall and the electrode assembly to fix the electrode assembly from multiple directions, further improving the position stability of the electrode assembly.

[0010] According to some embodiments of the embodiments of the present application, the expandable member is connected and arranged on the first shell wall; and / or, the expandable member is connected and arranged on the second shell wall; and / or, the expandable member is connected and arranged on the electrode assembly. The expandable member can be optionally connected and arranged with any one or several of the first shell wall, the second shell wall or the electrode assembly, making its installation position flexibly adjustable.

[0011] According to some embodiments of the embodiments of the present application, the battery cell includes a plurality of expandable members, and the plurality of expandable members are arranged at intervals in a third direction, or the plurality of expandable members are arranged at intervals along the circumferential direction of the electrode assembly. The first direction, the second direction and the third direction intersect pairwise. A plurality of expandable members can be arranged in the battery cell at the same time, and these expandable members can be optionally arranged in different arrangements to improve the force uniformity of the electrode assembly and further improve the reliability of the battery cell.

[0012] According to some embodiments of the embodiments of the present application, the electrode assembly includes a straight region and two bent regions. The straight region connects the two bent regions, and the bent regions are arranged on one side of the straight region close to the first shell wall; at least a part of the expandable member is arranged between the surface of the bent region far from the straight region and the first shell wall, and the expandable member extends along the third direction. In embodiments where the electrode assembly is processed by winding or other methods and has bent regions on the sides, the expandable member can be arranged on the side of the bent region and extend along the axial direction of the bent region, making the connection between the expandable member and the electrode assembly more stable.

[0013] According to some embodiments of the embodiments of the present application, expandable members are arranged between the bent region and the first shell wall and between the bent region and the second shell wall. The bent region with a curvature is fixed from two directions, further reducing the possibility of the electrode assembly shaking.

[0014] According to some embodiments of the present application, the electrode assembly is cylindrical, the first shell wall is tubular and disposed around the electrode assembly, and the expandable member extends at least partially along the circumference of the electrode assembly. In embodiments where the battery cell is a cylindrical battery, the expandable member can be disposed around the electrode assembly to further stabilize the relative position between the electrode assembly and the shell, thereby improving reliability.

[0015] According to some embodiments of the present application, a battery cell includes multiple expandable members, which are spaced apart along the axial direction of the electrode assembly. Arranging the multiple expandable members along the axial direction further evens out the force applied to the electrode assembly and reduces the possibility of shaking or displacement at various locations.

[0016] According to some embodiments of the present application, the battery cell further includes a heat conducting component disposed between the electrode assembly and the first shell wall and staggered relative to the expandable member. The heat conducting component disposed between the electrode assembly and the shell transfers heat outward, thereby improving the heat dissipation performance of the battery cell while conserving space.

[0017] According to some embodiments of the present application, the cross-sectional shape of the expandable member in a cross section perpendicular to its own extension direction is rectangular or trapezoidal, so that the contact surfaces on both sides of the expandable member are flat and have a certain area, thereby making the force provided by the expandable member more stable and reliable.

[0018] According to some embodiments of the present application, the expansion rate of the expandable member disposed between the first shell wall and the electrode assembly in the thickness direction of the first shell wall is 150%-1600%, so that the expandable member can abut against both sides after expansion and provide sufficient force to the electrode assembly.

[0019] According to some embodiments of the present application, the expandable member is made of a polyurethane adhesive, a polyacrylate adhesive, a polyester adhesive, or a modified ethylene-ester copolymer adhesive. The expandable member is made of expandable adhesive to provide a secure connection to the electrode assembly and / or the housing, minimizing the impact on the electrolyte.

[0020] According to some embodiments of the present application, the expandable element has a dimension L1 in the thickness direction of the first shell wall when unexpanded, and the spacing between the electrode assembly and the first shell wall is L2; 0.05 ≤ L1 / L2 ≤ 0.7. This ensures that the dimensions of the expandable element are compatible with the gap between the electrode assembly and the shell, facilitating assembly and ensuring stable compensating force after expansion.

[0021] According to some embodiments of the present application, the outer casing includes a housing and an end cap. The housing has an opening, and the end cap covers the opening. The housing includes a first housing wall. The outer casing of the battery cell can be constituted by the housing and the end cap together, and the first housing wall is arranged on the housing to reduce the possibility of interference between the expandable member and components such as the connecting piece at the end cap.

[0022] In a second aspect, the present application provides a battery device, including a plurality of battery cells in any one of the embodiments of the first aspect.

[0023] In a third aspect, the present application provides an electrical device, including the battery device in any one of the embodiments of the second aspect, and the battery device is used to provide electrical energy. Description of the Drawings

[0024] By reading the detailed description of the preferred embodiments below, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, in all the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0025] Figure 1 A simple schematic diagram of a vehicle provided by some embodiments of the present application;

[0026] Figure 2 An exploded view of a battery device provided by some embodiments of the present application;

[0027] Figure 3 An exploded view of a battery cell provided by some embodiments of the present application;

[0028] Figure 4 A cross-sectional structural schematic diagram of a battery cell provided by some embodiments of the present application;

[0029] Figure 5 A cross-sectional structural schematic diagram of a battery cell provided by some other embodiments of the present application;

[0030] Figure 6 A cross-sectional structural schematic diagram of a battery cell provided by some other embodiments of the present application;

[0031] Figure 7 A cross-sectional structural schematic diagram of a battery cell provided by some other embodiments of the present application;

[0032] Figure 8 A cross-sectional structural schematic diagram of a battery cell provided by some other embodiments of the present application;

[0033] Figure 9 A cross-sectional structural schematic diagram of a battery cell provided by some other embodiments of the present application;

[0034] Figure 10 Schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application;

[0035] Figure 11 Schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application;

[0036] Figure 12 Schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application;

[0037] Figure 13 Schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application.

[0038] Reference numerals:

[0039] 1000 - Vehicle;

[0040] 100 - Battery cell; 200 - Battery device; 300 - Controller; 400 - Motor;

[0041] 10 - Outer shell; 20 - Electrode assembly; 30 - Electrolyte; 40 - Expandable member; 50 - Box body; 60 - Heat conduction assembly;

[0042] 11 - First shell wall; 12 - Second shell wall; 13 - Housing; 14 - End cap; 21 - Straight region; 22 - Bent region; 51 - First box body portion; 52 - Second box body portion; 53 - Accommodating portion;

[0043] 131 - Opening;

[0044] X - First direction; Y - Second direction; Z - Third direction. Detailed implementation manners

[0045] Hereinafter, embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application, and thus are only examples and cannot be used to limit the protection scope of the present application.

[0046] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0047] In the description of the embodiments of the present application, technical terms such as "first" and "second" are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "a plurality of" is more than two, unless otherwise specifically defined.

[0048] Reference to "embodiments" in this document means that the specific features, structures, or characteristics described in connection with the embodiments may be included in at least one embodiment of the present 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 herein may be combined with other embodiments.

[0049] In the description of the embodiments of the present application, the term "and / or" is merely a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally represents an "or" relationship between the associated objects before and after.

[0050] In the description of the embodiments of the present application, the term "a plurality of" refers to more than two (including two). Similarly, "a plurality of groups" refers to more than two groups (including two groups), and "a plurality of pieces" refers to more than two pieces (including two pieces).

[0051] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0052] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0053] In the embodiments of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be activated by charging after discharging so that the active material can be reused.

[0054] 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 the present application are not limited thereto.

[0055] The battery cell generally includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charge and discharge process of the battery cell, active ions (such as lithium ions) are inserted and extracted 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 the short circuit between the positive and negative electrodes and allow the active ions to pass through.

[0056] In some embodiments, the positive electrode may be a positive electrode sheet, and the positive electrode sheet may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector.

[0057] As an example, the positive electrode current collector has two surfaces opposite to each other in its own thickness direction, and the positive electrode active material is disposed on any one or both of the two opposite surfaces of the positive electrode current collector.

[0058] As an example, the positive electrode current collector may be a metal foil or a composite current collector.

[0059] In some embodiments, the negative electrode may be a negative electrode sheet, and the negative electrode sheet may include a negative electrode current collector.

[0060] As an example, the negative electrode current collector may be a metal foil, a foam metal, or a composite current collector.

[0061] As an example, the negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0062] 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 any one or both of the two opposite surfaces of the negative electrode current collector.

[0063] As an example, the negative electrode active material may be a negative electrode active material known in the art for battery cells. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc.

[0064] In some embodiments, the material of the positive electrode current collector may be aluminum, and the material of the negative electrode current collector may be copper.

[0065] In some embodiments, the electrode assembly further includes a separator disposed between the positive electrode and the negative electrode.

[0066] In some embodiments, the separator is a separator membrane. The present application does not particularly limit the type of the separator membrane, and any publicly known porous structure separator membrane with good chemical stability and mechanical stability can be selected.

[0067] As an example, the main material of the separator membrane can be selected from at least one of glass fiber, non-woven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramics.

[0068] 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.

[0069] In some embodiments, the battery cell 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.

[0070] In some embodiments, the electrode assembly is provided with tabs, and the tabs can lead out the current from the electrode assembly. The tabs include a positive tab and a negative tab.

[0071] 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.

[0072] In some embodiments, functional components such as electrode terminals can be provided on the housing. The electrode terminals can be used for electrically connecting to the electrode assembly to output or input the electrical energy of the battery cell.

[0073] 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 particular limitation.

[0074] The battery device mentioned in the embodiments of the present application may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel, or in a mixed connection through a busbar component.

[0075] In some embodiments, a battery cell assembly is usually formed by arranging a plurality of battery cells; as an example, the battery cell assembly can be a battery module, and the battery module is formed by arranging and fixing a plurality of battery cells into an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with cable ties.

[0076] In some embodiments, the battery device can be a battery pack, and the battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body.

[0077] As an example, the battery cell assembly can be a battery module, and the battery cell assembly can be accommodated in the box body by fixing the battery module in the box body.

[0078] As an example, the battery cell assembly can also be accommodated in the box body by directly fixing a plurality of battery cells to the box body.

[0079] In some embodiments, the box body can be part of the chassis structure of a vehicle. For example, part of the box body can become at least part of the floor of the vehicle, or part of the box body can become at least part of the cross beam and longitudinal beam of the vehicle.

[0080] In some embodiments, the battery device can be an energy storage device. The energy storage device includes an energy storage container, an energy storage electrical cabinet, etc.

[0081] In a battery cell, it generally includes a housing and an electrode assembly, an electrolyte, etc. arranged in the housing. The electrode assembly can be directly or indirectly electrically connected to components such as electrode terminals on the housing, and is partially immersed in the electrolyte to provide corresponding charge and discharge functions. For reasons such as facilitating assembly and leaving expansion space for the electrode assembly, there is usually a certain gap between the electrode assembly and the housing.

[0082] However, during the working process, there is a possibility that the battery cell is subjected to external impacts or accelerations in a certain direction. In such cases, problems such as the electrode assembly being prone to shaking, displacement, and mutual collision with the housing in the housing are likely to occur, resulting in the electrode assembly being easily damaged, and further resulting in relatively low reliability of the battery cell.

[0083] In view of this, the embodiments of the present application provide a technical solution, which applies a pressing force to the electrode assembly by setting an expandable member between the electrode assembly and the housing wall of the housing, so that the relative position between the electrode assembly and the housing is stable, thereby reducing the possibility of the electrode assembly shaking or colliding, and improving the overall reliability of the battery cell.

[0084] The technical solutions described in the embodiments of the present application are applicable to battery devices and electrical devices using battery devices. The electrical devices include, for example, mobile phones, portable devices, laptop computers, battery cars, electric vehicles, ships, spacecrafts, electric toys, and electric tools, etc. Among them, spacecrafts include, for example, airplanes, rockets, space shuttles, and spaceships, etc. Electric toys include, for example, fixed or mobile electric toys, specifically, for example, game consoles, electric vehicle toys, electric ship toys, and electric airplane toys, etc. Electric tools include, for example, metal cutting electric tools, grinding electric tools, assembly electric tools, and railway electric tools, specifically, for example, electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact electric drills, concrete vibrators, and electric planers.

[0085] The battery cells described in the embodiments of the present application are not limited to the above-described electrical devices. However, for the sake of simplicity of description, the following embodiments will be described by taking electric vehicles as an example.

[0086] Please refer to Figure 1 , Figure 1 which is a schematic diagram of a vehicle 1000 provided by some embodiments of the present application. The vehicle 1000 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 battery device 200 can be disposed inside the vehicle 1000. Specifically, for example, the battery device 200 can be disposed at the bottom, the front end, or the rear end of the vehicle 1000. The battery device 200 can be used for power supply of the vehicle 1000. For example, the battery device 200 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can also include a controller 300 and a motor 400. The controller 300 is used to control the power supply of the battery to the motor 400, for example. The battery can be used for starting, navigation, etc. of the vehicle 1000. Of course, the battery device 200 can also be used to drive the vehicle 1000 to travel, replacing or partially replacing fuel or natural gas to provide drive for the vehicle 1000.

[0087] Figure 2 which is an exploded view of a battery device 200 provided by some embodiments of the present application. As Figure 2 shown, the battery device 200 includes a box body 50 and battery cells 100. The battery cells 100 are accommodated in the box body 50.

[0088] The housing 50 is used to accommodate the battery cells 100, and the housing 50 can have various structures. In some embodiments, the housing 50 may include a first housing portion 51 and a second housing portion 52. The first housing portion 51 and the second housing portion 52 are covered with each other, and the first housing portion 51 and the second housing portion 52 jointly define a receiving portion 53 for accommodating the battery cells. The second housing portion 52 can be a hollow structure with an open end, and the first housing portion 51 is a plate-like structure. The first housing portion 51 covers the open side of the second housing portion 52 to form a housing with the receiving portion 53; both the first housing portion 51 and the second housing portion 52 can also be hollow structures with an open side, and the open side of the first housing portion 51 covers the open side of the second housing portion 52 to form a housing 50 with the receiving portion 53. Of course, the first housing portion 51 and the second housing portion 52 can have various shapes, such as a cylinder, a cuboid, etc.

[0089] In the battery device 200, there can be one or more battery cells 100. If there are multiple battery cells 100, the multiple battery cells 100 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that there are both series and parallel connections among the multiple battery cells 100. The multiple battery cells 100 can be directly connected in series, in parallel, or in a hybrid connection together, and then the whole formed by the multiple battery cells 100 is accommodated in the housing 50; of course, it can also be that multiple battery cells 100 are first connected in series, in parallel, or in a hybrid connection to form battery modules, and then multiple battery modules are connected in series, in parallel, or in a hybrid connection to form a whole and are accommodated in the housing 50.

[0090] In some embodiments, there are multiple battery cells 100. The multiple battery cells 100 are first connected in series, in parallel, or in a hybrid connection to form battery modules. Then multiple battery modules are connected in series, in parallel, or in a hybrid connection to form a whole and are accommodated in the housing 50.

[0091] Next, in combination with the appended Figure 3 to the appended Figure 13 the structures of the battery cell 100, the battery device 200, and the electrical device will be described.

[0092] Please also refer to Figures 3 to 5 , Figure 3 which is an exploded view of the battery cell provided in some embodiments of the present application, Figure 4 which is a schematic cross-sectional structure view of the battery cell provided in some embodiments of the present application, Figure 5 which is a schematic cross-sectional structure view of the battery cell provided in some other embodiments of the present application.

[0093] In a first aspect, the present application provides a battery cell 100, which includes a housing 10, an electrolyte 30, an electrode assembly 20, and an expandable member 40. The housing 10 includes a first shell wall 11; the electrolyte 30 is accommodated in the housing 10; the electrode assembly 20 is disposed in the housing 10; the expandable member 40 is accommodated in the housing 10, and at least a part of the expandable member 40 is disposed between the first shell wall 11 and the electrode assembly 20. The expandable member 40 abuts against the first shell wall 11 and the electrode assembly 20 respectively, and the expandable member 40 is configured to expand when encountering the electrolyte 30.

[0094] The present application provides a battery cell 100, which includes a housing 10, and an electrolyte 30, an electrode assembly 20, and an expandable member 40 disposed in the housing 10. The housing 10 encloses to form a receiving cavity with certain sealing performance, and the electrolyte 30, the electrode assembly 20, and the expandable member 40 are all disposed in the receiving cavity.

[0095] Optionally, the housing 10 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the housing 10 can be determined according to the specific shape of the electrode assembly 20. In an embodiment where the electrode assembly 20 is a cylinder structure, a cylinder housing 10 can be selected; in an embodiment where the electrode assembly 20 is a cuboid structure, a cuboid housing 10 can be selected. The housing 10 includes a first shell wall 11, and the first shell wall 11 can be selected as the side wall of the housing 10, and its shape is designed according to the overall shape of the housing 10, such as extending along an arc surface or along a plane.

[0096] The electrode assembly 20 is accommodated in the receiving cavity of the housing 10, and is optionally electrically connected to the electrode terminals on the housing 10 to output or input electrical energy through the electrode terminals. The electrode assembly 20 can include a positive electrode plate, a negative electrode plate, and a separator sandwiched between the two. The electrode assembly 20 can be a wound electrode assembly 20, a stacked electrode assembly 20, or other forms of electrode assemblies 20. One or more electrode assemblies 20 can be accommodated in the housing 10 at the same time. In an embodiment where there are multiple electrode assemblies 20, the multiple electrode assemblies 20 are optionally arranged in sequence along the stacking direction of their own electrode plates.

[0097] There can be a certain gap between the electrode assembly 20 and the inner wall of the housing 10, and the expandable member 40 is disposed in this gap. The expandable member 40 is made of a material that can expand after being immersed in the electrolyte 30, and is at least partially sandwiched between the first shell wall 11 and the electrode assembly 20. The expandable member 40 is optionally capable of expanding until its opposite side surfaces respectively abut against the electrode assembly 20 and the first shell wall 11, so as to fix the relative position between the electrode assembly 20 and the housing 10.

[0098] Optionally, the outer casing 10 may have two first casing walls 11 disposed opposite to each other, and an expandable member 40 may be disposed between the two first casing walls 11 and the electrode assembly 20 to fix the electrode assembly 20 from opposite sides, further improving the overall structural stability of the battery cell 100. At the same time, the battery cell 100 may also optionally include expandable members 40 disposed at other positions to fix the electrode assembly 20 from multiple directions jointly.

[0099] Optionally, the expandable member 40 may have a certain elasticity to adapt to the expansion of the electrode assembly 20 in the working state. Exemplarily, as the working time extends, the negative active material in the negative electrode tab of the electrode assembly 20 usually undergoes a volume change, resulting in an overall volume expansion of the electrode assembly 20. The expandable member 40 after swelling by absorbing liquid may have a certain elastic deformation ability to maintain the fixation of its position after the electrode assembly 20 expands, further improving the overall structural stability and reliability of the battery cell 100.

[0100] In the technical solution of the embodiment of the present application, an electrode assembly 20 and an electrolyte 30 are disposed in the outer casing 10 of the battery cell 100, and at least a part of the electrode assembly 20 is immersed in the electrolyte 30. At the same time, an expandable member 40 capable of expanding when encountering the electrolyte 30 is further disposed between the first casing wall 11 of the outer casing 10 and the electrode assembly 20. The expandable member 40 can expand until its two side surfaces are respectively abutted against the first casing wall 11 and the electrode assembly 20 to press the electrode assembly 20, thereby enabling the relative position between the electrode assembly 20 and the outer casing 10 to be stable, reducing the possibility of the electrode assembly 20 shaking or colliding under external impacts and the like, and further improving the reliability of the battery cell 100. At the same time, the expandable member expands after encountering the electrolyte 30, making the battery cell 100 easy to assemble.

[0101] In some alternative embodiments, the expandable member 40 is adhesively connected to at least one of the first casing wall 11 and the electrode assembly 20.

[0102] Optionally, the aforementioned expandable member 40 may be made of a material with adhesiveness, or a glue layer may be provided on at least a part of the surface of the expandable member 40 to enable it to be adhesively connected to the outer casing 10 and / or the electrode assembly 20.

[0103] Optionally, the expandable member 40 may be adhesively connected to one of the outer shell 10 and the electrode assembly 20 first, and the electrode assembly 20 is installed in the outer shell 10. After the expandable member 40 is immersed in the electrolyte 30, it absorbs liquid and expands, and then the other side opposite to the adhesive side expands to abut against the other of the outer shell 10 and the electrode assembly 20. Through its own viscosity and the acting force generated by expansion, it is adhesively connected to the other, so that connections are formed on both opposite sides of the expandable member 40, thereby further reducing the possibility of the expandable member 40 falling off and being displaced.

[0104] By directly adhesively connecting the expandable member 40 to the first shell wall 11 and / or the electrode assembly 20, the space required for additionally arranging fixing members can be saved and the cost can be reduced.

[0105] Please refer to Figure 6 and Figure 7 , Figure 6 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application, Figure 7 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application.

[0106] In some alternative embodiments, the battery cell 100 includes two first shell walls 11 oppositely arranged in the first direction X and two second shell walls 12 oppositely arranged in the second direction Y. The first direction X intersects with the second direction Y, and the area of the second shell wall 12 is larger than the area of the first shell wall 11.

[0107] In some alternative embodiments, a part of the expandable member 40 is arranged between the second shell wall 12 and the electrode assembly 20, and the opposite two side surfaces respectively abut against the second shell wall 12 and the electrode assembly 20.

[0108] Optionally, the battery cell 100 may be a square shell battery in the shape of a nearly cuboid. In this embodiment, the outer shell 10 may have four side walls and opposite top and bottom walls. Among them, the four side walls may include two first shell walls 11 oppositely arranged in the first direction X and two second shell walls 12 oppositely arranged in the second direction Y. The first direction X and the second direction Y may be optionally arranged perpendicular to each other.

[0109] Specifically, the area of the first shell wall 11 may be smaller than the area of the second shell wall 12. The stacking direction of the electrode plates in the electrode assembly 20 may be the second direction Y, that is, the electrode plates may partially extend parallel to the second shell wall 12. It can be understood that in this embodiment, the electrode assembly 20 itself usually expands on the side with a larger area, that is, along the second direction Y, providing a certain limiting effect for the electrode assembly 20. Therefore, arranging the expandable member 40 between the electrode assembly 20 and the first shell wall 11 can enable the expandable member 40 to play a more sufficient role.

[0110] Optionally, expandable members 40 can be provided between the two first cell walls 11 and the two second cell walls 12 and the electrode assembly 20, so that the electrode assembly 20 can be pressed and fixed in four directions, further improving the position stability of the electrode assembly 20 and the overall reliability of the battery cell 100.

[0111] The battery cell 100 can be a square-shell battery, and expandable members 40 are provided between two opposite sets of side walls and the electrode assembly 20, which can further reduce the possibility of the electrode assembly 20 shaking and further improve the overall reliability of the battery cell 100.

[0112] In some alternative embodiments, the expandable member 40 is connected to the first cell wall 11; and / or, the expandable member 40 is connected to the second cell wall 12; and / or, the expandable member 40 is connected to the electrode assembly 20.

[0113] The expandable member 40 can be connected to at least one of the outer shell 10 and the electrode assembly 20 opposite to its two sides. Specifically, taking the expandable member 40 disposed between the first cell wall 11 and the electrode assembly 20 as an example, the expandable member 40 can be optionally connected to any one of the first cell wall 11 and the electrode assembly 20, or both sides of the expandable member 40 can be respectively connected to the first cell wall 11 and the electrode assembly 20. In the embodiment of single-sided connection, the expandable member 40 can be optionally disposed on and connected to this side before expansion; in the embodiment of double-sided connection, it can be further connected to both sides through its own expansion.

[0114] The connection manner of the expandable member 40 disposed between the second cell wall 12 and the electrode assembly 20 is similar to the above expandable member 40, and will not be elaborated herein in this application.

[0115] The expandable member 40 can be optionally connected to any one or several of the first cell wall 11, the second cell wall 12 or the electrode assembly 20, so that its installation position can be flexibly adjusted and can be adaptively adjusted according to the shape and structure of the electrode assembly 20 and the outer shell 10.

[0116] In some alternative embodiments, the battery cell 100 includes a plurality of expandable members 40, and the plurality of expandable members 40 are arranged at intervals along the third direction Z, or the plurality of expandable members 40 are arranged at intervals along the circumferential direction of the electrode assembly 20, and the first direction X, the second direction Y and the third direction Z intersect pairwise.

[0117] Optionally, a plurality of expandable members 40 may be disposed inside the housing 10 of the battery cell 100. These expandable members 40 may extend parallel to the housing 10 in the first direction X, the second direction Y, or a direction close to both of the foregoing, and are spaced apart in the third direction Z, and may be equally spaced.

[0118] Alternatively, the plurality of expandable members 40 may extend in the third direction Z or a direction close to the third direction Z, and are spaced apart in the circumferential direction of the electrode assembly 20. Within the range corresponding to each housing wall, the expandable members 40 may be equally spaced.

[0119] A plurality of expandable members 40 may be disposed in the battery cell 100 at the same time. These expandable members 40 may be arranged in different ways according to their own extension directions and the structural form of the electrode assembly 20, etc., so as to provide acting forces in a plurality of different directions and positions, thereby improving the force uniformity of the electrode assembly 20 and further improving the reliability of the battery cell 100.

[0120] Please refer to Figures 8 to 10 , Figure 8 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application, Figure 9 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application, Figure 10 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application.

[0121] In some alternative embodiments, the electrode assembly 20 includes a flat region 21 and two bent regions 22. The flat region 21 connects the two bent regions 22, and the bent regions 22 are disposed on one side of the flat region 21 close to the first housing wall 11; at least part of the expandable members 40 are disposed between the surface of the bent region 22 away from the flat region and the first housing wall 11, and the expandable members 40 extend along the third direction Z.

[0122] Optionally, the electrode assembly 20 may include a flat region 21 and a bent region 22. The electrode sheets and the separator in the flat region 21 may extend along a plane, and the electrode sheets and the separator in the bent region 22 may be bent and connected between the respective electrode sheets in the flat region 21 to connect the electrode sheets and the separators in the flat region 21 into one body.

[0123] Optionally, bent regions 22 are provided on both opposite sides of the flat region 21 in the first direction X. The surface of the bent region 22 away from the flat region 21 may be an arc surface, and expandable members 40 may be provided on this arc surface. The opposite sides of the expandable members 40 in the first direction X are respectively abutted against the electrode assembly 20 and the first housing wall 11.

[0124] Optionally, since the side surface of the flat region 21 close to the first housing wall 11 is an arc surface, in an embodiment where the first housing wall 11 is an arc wall surface conforming to it, the expandable member 40 can be provided at each part of the arc surface, and the expandable member 40 can extend along the third direction Z.

[0125] In an embodiment where the first housing wall 11 is a plane, the expandable member 40 can be provided at the position on the arc surface where the distance from the first housing wall 11 is the smallest, that is, at the most protruding straight line position extending along the third direction Z on the arc surface, so that the expandable member 40 can better abut against both sides in the first direction X. Alternatively, a plurality of expandable members 40 can also be provided on the arc surface, and these expandable members 40 are symmetrically arranged with respect to a reference plane, which can be parallel to the third direction Z, and the bending region 22 can also be symmetrically arranged with respect to this reference plane, thereby enabling the bending region 22 to be uniformly stressed.

[0126] In an embodiment where the electrode assembly 20 is processed by winding or the like and has a bending region 22 on the side, the expandable member 40 can be provided on the side of the bending region 22 and extend along the axial direction of the bending region 22, that is, the third direction Z, so that the connection between the expandable member 40 and the electrode assembly 20 is more stable, reducing the possibility of problems such as unstable abutment or easy deformation of the expandable member 40 due to the unevenness of the surface of the bending region 22 or easy peeling from the electrode assembly 20.

[0127] In some alternative embodiments, expandable members 40 are provided both between the bending region 22 and the first housing wall 11 and between the bending region 22 and the second housing wall 12.

[0128] In an embodiment where the electrode assembly 20 has a bending region 22, the bending region 22 can be circular arc-shaped with the axial direction being the third direction Z. At this time, expandable members 40 can be provided between the arc surface of the bending region 22 and the first housing wall 11 as well as the second housing wall 12.

[0129] Specifically, a plurality of expandable members 40 can be provided near the bending region 22. For example, expandable members 40 can be provided between the two sides of the bending region 22 and the two second housing walls 12 respectively, and at least one expandable member 40 can be provided between the bending region 22 and the first housing wall 11. These expandable members 40 are optionally all extended along the third direction Z. Alternatively, expandable members 40 can be provided in two directions near the junction of the bending region 22 and the first housing wall 11 and the second housing wall 12, and each expandable member 40 can have a larger cross-sectional area and abut against both the first housing wall 11 and the second housing wall 12 at the same time.

[0130] By arranging expandable members 40 between the bent region 22 and the first housing wall 11 and the second housing wall 12, it is possible to fix the bent region 22 with a curvature from two different directions intersecting each other, thereby further reducing the possibility of the electrode assembly 20 shaking.

[0131] Please refer to Figure 11 and Figure 12 , Figure 11 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application, Figure 12 which is a schematic cross-sectional structure diagram of a battery cell provided in some other embodiments of the present application.

[0132] In some alternative embodiments, the electrode assembly 20 is cylindrical, the first housing wall 11 is cylindrical and arranged around the electrode assembly 20, and the expandable member 40 extends at least partially along the circumference of the electrode assembly 20.

[0133] Corresponding to the foregoing embodiment of the square shell battery, the battery cell 100 may also be a cylindrical battery. In this embodiment, the outer shell 10 is of a cylindrical structure and encloses a cylindrical accommodation space. The electrode assembly 20 may be a wound structure and is also cylindrical. The first housing wall 11 may be a side wall extending in a cylindrical shape in the outer shell 10 and arranged around the electrode assembly 20.

[0134] Optionally, in the embodiment of the cylindrical battery, the expandable member 40 may be selected to extend at least partially along the circumference of the electrode assembly 20, that is, the expandable member 40 may be strip-shaped and arranged around the electrode assembly 20, so that the expandable member 40 can fix the electrode assembly 20 from multiple directions. The expandable member 40 may be selected to extend completely along the circumference and be arranged in a ring shape, or the expandable member 40 may include a plurality of sub-members spaced apart in the circumferential direction, and each sub-member may have the same length and be equally spaced.

[0135] In the embodiment where the battery cell 100 is a cylindrical battery, the expandable member 40 can be arranged around the electrode assembly 20 to apply a force to the electrode assembly 20 from multiple different radial directions, thereby making the relative position between the electrode assembly 20 and the outer shell 10 more stable and improving the reliability.

[0136] In some alternative embodiments, the battery cell 100 includes a plurality of expandable members 40, and the plurality of expandable members 40 are arranged at intervals along the axial direction of the electrode assembly 20.

[0137] In an embodiment where the expandable member 40 is circumferentially disposed around the electrode assembly 20, the battery cell 100 may be provided with a plurality of expandable members 40, and the plurality of expandable members 40 are axially distributed along the electrode assembly 20. Optionally, the plurality of expandable members 40 may be equally spaced along the axis, and the size of the expandable member 40 may be correspondingly adjusted according to the specific shape of the housing 10, the dimension between the first housing wall 11 and the electrode assembly 20, etc., so as to fix each position of the electrode assembly 20 in the axial direction, reduce the possibility of one end of the electrode assembly 20 shaking, and thus improve the overall reliability of the battery cell 100.

[0138] Please refer to Figure 13 , Figure 13 which is a schematic cross-sectional structure view of the battery cell provided in some other embodiments of the present application. In some alternative embodiments, the battery cell 100 further includes a heat conduction assembly 60, and the heat conduction assembly 60 is disposed between the electrode assembly 20 and the first housing wall 11 and is staggeredly arranged with the expandable member 40.

[0139] Optionally, a heat conduction assembly 60 may also be disposed inside the battery cell 100 for conducting the heat generated by the electrode assembly 20 to the housing 10. Similar to the expandable member 40, the heat conduction assembly 60 may be disposed at the gap between the electrode assembly 20 and the first housing wall 11 and is staggeredly arranged with the expandable member 40.

[0140] Optionally, the heat conduction assembly 60 may have a larger area and surround the expandable member 40 therein to provide a certain auxiliary positioning function for the expandable member 40. The heat conduction assembly 60 is optionally made of a material such as heat-conducting silica gel and is optionally arranged to surround the electrode assembly 20 to uniformly improve the heat dissipation performance in all directions.

[0141] By disposing the heat conduction assembly 60 between the electrode assembly 20 and the housing 10, the heat of the electrode assembly 20 can be transferred outwards, and the heat dissipation performance of the battery cell 100 can be improved on the premise of saving space.

[0142] In some alternative embodiments, the cross-sectional pattern formed by the expandable member 40 in a cross-section perpendicular to its own extension direction is a rectangle or a trapezoid.

[0143] The expandable member 40 in the battery cell 100 may be arranged in a strip, block, mesh or other structural forms. Here, the extension direction refers to its length direction, and the cross-section perpendicular to its own extension direction may refer to a cross-section perpendicular to the length direction. In an embodiment where the expandable member 40 is in a block shape, the cross-section perpendicular to its own extension direction may refer to a cross-section parallel to its thickness direction, that is, the expansion direction.

[0144] Optionally, within the aforementioned cross-section, the cross-sectional shape formed by the expandable member 40 can be a rectangle or a trapezoid. In an embodiment where the cross-sectional shape is a rectangle, the long sides of the rectangle can be located on both sides close to the electrode assembly 20 / the housing 10, or the long sides of the rectangle can be connected between the electrode assembly 20 and the housing 10.

[0145] In an embodiment where the cross-sectional shape is a trapezoid, the trapezoid can be an optionally right trapezoid, isosceles trapezoid, irregular trapezoid, etc., and the edge with a shorter length on one side thereof can be optionally arranged opposite to the initial connection side of the expandable member 40. Exemplarily, before expansion, the expandable member 40 is adhesively connected to the electrode assembly 20, then in the trapezoidal cross-section formed after its expansion, the shorter edge can be located on the side close to the housing 10 to further make the connection between the expandable member 40, the electrode assembly 20, and the housing 10 stable and reliable.

[0146] By making the cross-sectional shape of the expandable member 40 pair a rectangle or a trapezoid, the abutting surfaces on both sides thereof can be made flat and have a certain area, thereby making the force provided by it more stable and reliable and making the position of the electrode assembly 20 more stable.

[0147] In some optional embodiments, in the thickness direction of the first shell wall 11, the expansion rate of the expandable member 40 disposed between the first shell wall 11 and the electrode assembly 20 is 150% - 1600%.

[0148] The expandable member 40 can generate volume expansion after being immersed in the electrolyte 30. Optionally, taking the expandable member 40 disposed between the first shell wall 11 and the electrode assembly 20 as an example, when expanding in the thickness direction of the first shell wall 11, that is, the direction mainly providing the force by itself, its own expansion rate can be optionally 150% - 1600%, that is, the ratio of the size of the expandable member 40 after expansion to the size of the expandable member 40 before expansion in this direction, and the size after expansion can be 1.5 times - 16 times the size before expansion.

[0149] Optionally, in an embodiment where there is a second shell wall 12 and an expandable member 40 is also disposed between the second shell wall 12 and the electrode assembly 20, this part of the expandable member 40 can be made of the same material, have the same structure, and have the same expansion rate as the expandable member 40 disposed between the first shell wall 11 and the electrode assembly 20.

[0150] By adjusting the thickness and expansion rate of the expandable member 40, the thickness of the expandable member 40 after expansion can be adjusted more flexibly to ensure that it can abut between the housing 10 and the electrode assembly 20 and provide sufficient force, thereby improving the structural stability and position stability of the electrode assembly 20.

[0151] In some alternative embodiments, the expandable member 40 is a polyurethane-based adhesive, a polyacrylate-based adhesive, a polyester-based adhesive, or a modified ethylene-ester copolymer adhesive.

[0152] To enable the expandable member 40 to be conveniently connected to the electrode assembly 20 and / or the housing 10, the expandable member 40 is preferably made of an expanding adhesive, specifically, preferably made of a polyurethane-based adhesive, a polyacrylate-based adhesive, a polyester-based adhesive, or a modified ethylene-ester copolymer adhesive. The expandable member 40 made of the aforementioned materials can expand after being immersed in the electrolyte 30 and has good stability, and is not easily interfered with by the electrolyte 30.

[0153] Setting the expandable member 40 to be made of the aforementioned expanding adhesive enables it to be adhesively connected to the electrode assembly 20 and / or the housing 10 through its own viscosity, saving the space and cost required for separately providing an adhesive, and at the same time enabling the expandable member 40 to be firmly connected to the electrode assembly 20 and / or the housing 10, reducing the mutual interference with the electrolyte 30.

[0154] It can be understood that the above materials are only examples, and other suitable materials can also be used to make the expandable member 40 in the battery cell 100, as long as the material can expand after being immersed in the electrolyte and does not react with the electrolyte. Specifically, further screening can be carried out according to the expansion rate, processing difficulty, and cost of the material, etc.

[0155] In some alternative embodiments, in the thickness direction of the first housing wall 11, the size of the expandable member 40 in the unexpanded state is L1, and the distance between the electrode assembly 20 and the housing 13 is L2; 0.05 ≤ L1 / L2 ≤ 0.7.

[0156] In some embodiments, the thickness dimension of the expandable member 40 before expansion is denoted as L1, and the distance between the electrode assembly 20 and the housing 13 is denoted as L2, then the ratio of L1 to L2 can be between 0.05 and 0.7, further preferably between 0.0625 and 0.67, for example, it can be any one of 0.0625, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.67 or between any two of them.

[0157] Optionally, the final thickness to which the expandable member 40 in the battery cell 100 can expand can be calculated according to the material selected and its own structural form. The initial thickness of the expandable member 40, that is, the thickness before expansion, can be relatively small. After being infiltrated and expanded by the electrolyte 30, its specific thickness after expansion can be judged according to the aforementioned expansion rate and other parameters.

[0158] By adjusting the ratio of the thickness of the expandable member 40 before expansion to the distance between the electrode assembly 20 and the outer casing 10, it is possible to cooperate with the expansion rate to make the thickness of the expandable member 40 after liquid absorption and expansion fall within a preset range, so that its opposite side surfaces can stably abut against the electrode assembly 20 and the outer casing 10.

[0159] At the same time, setting the expandable member 40 to have a relatively small thickness dimension before expansion can provide sufficient space margin for the electrode assembly 20, enabling it to have a certain assembly error space during the assembly process with the outer casing 10, and thus facilitating the assembly of the electrode assembly 20.

[0160] In some alternative embodiments, the outer casing 10 includes a housing 13 and an end cap 14. The housing 13 has an opening 131, and the end cap 14 covers the opening 131; the housing 13 includes a first shell wall 11.

[0161] Optionally, the outer casing 10 of the battery cell 100 can be composed of two parts, namely the housing 13 and the end cap 14. The housing 13 encloses to form a receiving cavity and has an opening 131 communicating with the receiving cavity. The end cap 14 covers the opening 131 and can be optionally detachably or fixedly connected to the housing 13. Optionally, components such as electrode terminals and a pressure relief mechanism are provided on the end cap 14 to achieve corresponding electrical connection and other functions, and the end cap 14 and the housing 13 can be optionally connected by welding.

[0162] Among them, the end cap 14 can have various structures. For example, it can be a plate-like structure, a hollow structure with an opening 131 at one end, etc. The end cap 14 can be made of an insulating material (such as plastic) or a conductive material (such as metal).

[0163] Optionally, the outer casing 10 can include a housing 13 with a single opening 131 and an end cap 14. Alternatively, the outer casing 10 can include a housing 13 in the shape of a cylinder with openings 131 at both ends and two end caps 14. The two end caps 14 respectively cover the two openings 131 of the housing 13 and form a sealed connection to form a receiving cavity for accommodating the electrode assembly 20 and the electrolyte 30.

[0164] The first shell wall 11 is disposed in the housing 13, and can be optionally the side wall of the housing 13, that is, the wall portion not opposite to the end cap 14, so as to reduce the possibility of the expandable member 40 disposed between the electrode assembly 20 and the first shell wall 11 interfering with the connection between the electrode assembly 20 and the electrode terminal, the release of the pressure relief mechanism, etc. Optionally, in an embodiment where the outer casing 10 has a second shell wall 12, the second shell wall 12 can also be disposed in the housing 13 and be alternately arranged with the first shell wall 11 in the circumferential direction of the opening 131 to form a cuboid-shaped housing 13.

[0165] In a second aspect, the present application provides a battery device 200, which includes a plurality of battery cells 100 in any of the embodiments of the first aspect.

[0166] In a third aspect, the present application provides an electrical device, which includes the battery device 200 in any of the embodiments of the second aspect, and the battery device 200 is used to provide electrical energy.

[0167] The battery device 200 and the electrical device in the embodiments of the present application have all the beneficial effects of the battery cell 100 in the first aspect. For specific descriptions of the battery cell 100, reference may be made to the above embodiments, and details are not repeated herein.

[0168] An embodiment of the present application provides a battery cell 100, which includes a housing 10, an electrolyte 30, an electrode assembly 20, and an expandable member 40. The housing 10 includes two first shell walls 11 oppositely arranged in a first direction X and two second shell walls 12 oppositely arranged in a second direction Y; the electrolyte 30 is accommodated in the housing 10; the electrode assembly 20 is arranged in the housing 10; the expandable member 40 is accommodated in the housing 10, and a plurality of expandable members 40 are respectively arranged between the first shell wall 11 and the electrode assembly 20 and between the second shell wall 12 and the electrode assembly 20, and the opposite two side surfaces are respectively in contact with the first shell wall 11 /

[0169] the second shell wall 12 and the electrode assembly 20, and the expandable member 40 is configured to expand when encountering the electrolyte 30. The cross-sectional pattern formed by the expandable member 40 in a cross-section perpendicular to its own extension direction is a rectangle or a trapezoid, and the expansion rate of the expandable member 40 in the thickness direction is 150%-1600%.

[0170] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and are not intended to limit 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 recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by 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 housing including a first shell wall; An electrolyte accommodated within the housing; An electrode assembly disposed within the housing; An expandable member accommodated within the housing, at least a portion of the expandable member being disposed between the first shell wall and the electrode assembly, the expandable member being in contact with both the first shell wall and the electrode assembly, and the expandable member being configured to expand when encountering the electrolyte.

2. The battery cell according to claim 1, characterized in that, The expandable member is adhesively connected to at least one of the first shell wall and the electrode assembly.

3. The battery cell according to claim 1, characterized in that The battery cell includes two of the first shell walls oppositely disposed in a first direction and two second shell walls oppositely disposed in a second direction, the first direction intersecting the second direction, and the area of the second shell wall being greater than the area of the first shell wall.

4. The battery cell according to claim 3, characterized in that, At least a portion of the expandable member is disposed between the second shell wall and the electrode assembly, and opposite side surfaces thereof are in contact with the second shell wall and the electrode assembly respectively.

5. The battery cell according to claim 4, wherein, The expandable member is connected and disposed on the first shell wall; and / or, the expandable member is connected and disposed on the second shell wall; and / or, the expandable member is connected to the electrode assembly.

6. The battery cell according to claim 5, characterized in that, The battery cell includes a plurality of the expandable members, the plurality of expandable members being spaced apart along a third direction, or the plurality of expandable members being spaced apart circumferentially along the electrode assembly, the first direction, the second direction, and the third direction being pairwise intersecting.

7. The battery cell according to claim 3, wherein, The electrode assembly includes a flat region and two bent regions, the flat region connecting the two bent regions, and the bent regions being disposed on a side of the flat region close to the first shell wall; At least a portion of the expandable member is disposed between a surface of the bent region away from the flat region and the first shell wall, and the expandable member extends along the third direction.

8. The battery cell according to claim 7, characterized in that, The expandable member is disposed between the bent region and the first shell wall and between the bent region and the second shell wall.

9. The battery cell according to claim 1, characterized in that, The electrode assembly is cylindrical, the first shell wall is cylindrical and disposed around the electrode assembly, and at least a portion of the expandable member extends circumferentially along the electrode assembly.

10. The battery cell according to claim 9, characterized in that, The battery cell includes a plurality of expandable members, the plurality of expandable members being spaced apart axially along the electrode assembly.

11. The battery cell according to claim 1, wherein The battery cell further includes a heat conduction assembly disposed between the electrode assembly and the first shell wall and staggered from the expandable member.

12. The battery cell according to claim 1, wherein The cross-sectional shape formed by the expandable member in a cross-section perpendicular to its extension direction is a rectangle or a trapezoid.

13. The battery cell according to claim 1, characterized in that, In the thickness direction of the first shell wall, the expansion rate of the expandable member disposed between the first shell wall and the electrode assembly is 150%-1600%.

14. The battery cell according to claim 13, wherein, The expandable member is a polyurethane-based adhesive, a polyacrylate-based adhesive, a polyester-based adhesive, or a modified ethylene-ester copolymer adhesive.

15. The battery cell according to claim 13, wherein, In the thickness direction of the first shell wall, the size of the expandable member in the unexpanded state is L1, and the distance between the electrode assembly and the first shell wall is L2; 0.05 ≤ L1 / L2 ≤ 0.

7.

16. The battery cell according to claim 1, wherein The housing includes a shell and an end cap, the shell having an opening, and the end cap covering the opening; The housing includes the first housing wall.

17. A battery device, characterized in that, Comprising a plurality of battery cells according to any one of claims 1-16.

18. An electrical device, characterized in that, a battery device according to claim 17, the battery device being configured to provide electrical energy.

Images