Battery cell, battery device and electric device

Abstract

The utility model discloses a single battery, a battery device and a power utilization device, the single battery comprises: a housing assembly having an accommodating space; the electrode assembly is in a roll core shape and is arranged in the accommodating space; the binding assembly is arranged between the electrode assembly and the shell assembly and comprises a first binding piece and a second binding piece, the first binding piece is arranged around the circumferential direction of the electrode assembly, the second binding piece is arranged between the first binding piece and the electrode assembly, the second binding piece and the first binding piece are arranged in a spaced mode, and the second binding piece is arranged around the circumferential direction of the electrode assembly or comprises a first binding piece and a second binding piece; the second binding piece is connected with the first binding piece to form an annular part arranged around the electrode assembly in the circumferential direction, and the binding force of the second binding piece is smaller than that of the first binding piece. According to the utility model, the problem of electrode expansion can be well relieved, the probability of breakage of the pole piece of the electrode assembly in the later period of circulation is reduced, the reliability of the electrode assembly can be improved, and the reliability of the single battery is improved.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a battery cell, a battery device, and an electrical device. Background Art

[0002] New energy vehicles have experienced rapid growth in recent years. Batteries, as the power source, play an irreplaceable and crucial role in electric vehicles. Batteries consist of a housing and multiple cells housed within it. However, as core components of new energy vehicles, batteries have high reliability requirements. Improving the reliability of these cells has become a pressing issue. Utility Model Content

[0003] The embodiments of the present application provide a battery cell, a battery device, and an electrical device, which can effectively improve the reliability of the battery cell, the battery device, and the electrical device.

[0004] In the first aspect, an embodiment of the present application provides a battery cell, comprising: a shell assembly having a accommodating space; an electrode assembly in a roll core shape and disposed in the accommodating space; a restraining assembly disposed between the electrode assembly and the shell assembly, and comprising a first restraining member and a second restraining member, the first restraining member being disposed circumferentially around the electrode assembly, the second restraining member being disposed between the first restraining member and the electrode assembly, and being spaced apart from the first restraining member, the second restraining member being disposed circumferentially around the electrode assembly, or the second restraining member being connected to the first restraining member to form an annular member disposed circumferentially around the electrode assembly, and the restraining force of the second restraining member being less than the restraining force of the first restraining member.

[0005] In the above technical solution, because the restraining force of the second restraining member is less than that of the first restraining member, the second restraining member can exert a certain restraining force on the electrode assembly during the initial period of cyclic expansion, mitigating the rapid expansion of the electrode assembly within a short period of time. This reduces the likelihood of the electrode assembly's electrode sheets fracturing due to the high internal stress caused by the high restraining force in the early stages of the cycle. In the later stages of the cyclic expansion of the electrode assembly, after the irreversible expansion of the electrode assembly has concluded, the first restraining member can exert a greater restraining force on the electrode assembly, mitigating further expansion in the later stages of the cycle. This effectively mitigates electrode expansion issues, reduces the likelihood of electrode sheet fracturing in the later stages of the cycle, and improves the reliability of the electrode assembly and the battery cells.

[0006] In some embodiments of the present application, the electrode assembly includes a first arc-shaped portion, and the second restraining member is spaced apart from the first restraining member at least on one side facing away from the first arc-shaped portion.

[0007] In the above technical solution, since the first curved portion is the portion of the electrode assembly with a higher probability of fracture, the second restraining member is spaced apart from the first restraining member on at least one side facing away from the first curved portion. This allows the second restraining member to apply a smaller restraining force to the first curved portion during the initial cycle of the electrode assembly, slowing the expansion rate of the first curved portion 221 and mitigating the short-term, rapid expansion of the first curved portion. This, in turn, reduces the risk of fracture of the electrode segment located at the location of the first curved portion during the initial cycle. The first restraining member can apply a larger restraining force to the first curved portion during the later cycle of the electrode assembly, mitigating the expansion of the electrode segment located at the location of the first curved portion. This helps reduce the amount of expansion and deformation of the electrode segment located at the location of the first curved portion during the later cycle, thereby reducing the risk of fracture of the first curved portion. In other words, the above solution can reduce the risk of fracture of the electrode segment located at the location of the first curved portion in the electrode assembly, which helps reduce the risk of fracture of the entire electrode assembly, improve the reliability of the electrode assembly, and thereby improve the reliability of the battery cell.

[0008] In some embodiments of the present application, the electrode assembly has a first direction, a second direction and a third direction that are perpendicular to each other. The electrode assembly is wound around the first direction. The electrode assembly includes a first straight portion. The first straight portion is provided with a first arc-shaped portion at both ends of the second direction. The second restraining member is provided corresponding to the first arc-shaped portion and is connected to the first restraining member at both ends of the third direction.

[0009] In the above technical solution, the electrode assembly adopts the aforementioned structure in a square shape, thereby allowing the battery cells to be oriented as a whole, which is beneficial for improving the battery energy density when the battery cells are assembled into a battery device. Because the first straight portion has a lower risk of fracture than the first curved portion, the second restraining member adopts the aforementioned structure. While reducing the risk of fracture of the entire electrode assembly, the restraining assembly wall thickness in the third direction is reduced, thereby reducing the size of the battery cells in the third direction, which is beneficial for improving the energy density of the battery cells.

[0010] In some embodiments of the present application, the second restraining member is arc-shaped and is spaced apart from the first arc-shaped portion.

[0011] In the above technical solution, the second restraining member is arc-shaped and can match the shape of the first arc-shaped portion. As a result, after the second restraining member contacts the first arc-shaped portion, it can better conform to the surface of the first arc-shaped portion. The restraining force of the second restraining member can be more evenly distributed on the first arc-shaped portion, providing a more balanced restraining effect, thereby alleviating the expansion and deformation of the first arc-shaped portion. The second restraining member is spaced apart from the first arc-shaped portion. This can prevent the first arc-shaped portion from applying restraining force during the initial cycle of the electrode assembly. This facilitates better stress relief for the first arc-shaped portion during the initial cycle, reduces the probability of fracture caused by internal stress due to the restraining force during the rapid expansion of the first arc-shaped portion during the initial cycle, and further improves the reliability of the electrode assembly.

[0012] In some embodiments of the present application, the second restraining member includes a main body and a connecting portion, and the main body is provided with multiple connecting portions at both ends of the third direction, and the multiple connecting portions are arranged at intervals along the first direction; the first restraining member is provided with multiple recesses at both ends of the third direction, and the multiple recesses correspond to the multiple connecting portions one by one, and part of the connecting portion is arranged in the recess.

[0013] In the above technical solution, when the first curved portion expands in the second direction and gradually stretches the second restraint member until it contacts the first restraint member, both ends of the second restraint member in the third direction come into contact with the first restraint member. At this point, the recessed portion provides space for accommodating the connecting portion, which helps reduce the overall wall thickness of the restraint assembly in the third direction, saving space within the housing assembly. This allows for more space for the electrode assembly in the third direction, increases the volume of the electrode assembly, and improves the volumetric energy density of the battery cell. The second restraint member is configured to include a main body and multiple connecting portions. While achieving the above-mentioned effects, it also provides a certain degree of rigidity for the second restraint member, reduces the risk of deformation, and improves its structural reliability. The main body is connected to the multiple recessed portions of the first restraint member via the multiple connecting portions. This improves the connection reliability between the second restraint member and the first restraint member, enhances the overall rigidity of the restraint assembly, reduces the risk of deformation during assembly, improves the installation stability of the restraint assembly, and facilitates assembly of the restraint assembly into the housing assembly.

[0014] In some embodiments of the present application, the first restraining member includes a second straight portion and a second curved portion, the second curved portions are arranged at both ends of the second straight portion in the second direction, and the recess includes a first part and a second part that are connected, the first part is arranged on the second straight portion, and the second part is arranged on the second curved portion.

[0015] In the above technical solution, the first restraining member is configured in the aforementioned structure, so that its shape matches that of the electrode assembly. When the first curved portion stretches the second restraining member and contacts the first restraining member, the second curved portion, the second restraining member, and the first curved portion fit tightly together, thereby evenly distributing the restraining force of the second restraining member on the first curved portion, providing a better restraining effect on the first curved portion. This further mitigates expansion and deformation of the first curved portion during the later stages of the electrode assembly cycle, thereby reducing the probability of fracture of the electrode assembly. The aforementioned structure of the recess increases the storage space within the recess, provides a longer connecting portion, and reduces the overall thickness of the restraining assembly in the second direction, further saving space. This allows for the placement of a larger electrode assembly within the housing assembly, further improving the volumetric energy density of the battery cell.

[0016] In some embodiments of the present application, the first restraining member includes a second straight portion and a second curved portion, the second curved portion is arranged at both ends of the second straight portion in the second direction, at least one of the second curved portions located at both ends of the second direction includes a first split member and a first connecting member, there are two first split members, and they are arranged adjacent to each other in the third direction, and the first connecting member is bonded to the two first split members.

[0017] In the above technical solution, by setting the second arc-shaped portion into the above structure, the second restraint member can be installed into the first restraint member before the first coupling member and the two first split members are assembled. This can provide a larger space for the installation of the second restraint member, facilitate assembly, reduce the difficulty of installing the second restraint member, improve assembly and production efficiency, and also help to improve the quality stability of the restraint assembly.

[0018] In some embodiments of the present application, at least one of the second restraining members located at both ends of the second direction includes a second split member and a second joining member. There are two second split members, which are adjacently arranged in the third direction. The second joining member is adhesively connected to the two second split members.

[0019] In the above technical solution, by setting the second restraint member into the above structure, the two second split members can be respectively connected to the first restraint member first, and then the two second split members can be connected together through the second connecting member. This can reduce the difficulty of installing the second restraint member within the limited space of the first restraint member, improve assembly and production efficiency, and is also beneficial to improving the quality stability of the restraint component.

[0020] In some embodiments of the present application, the first restraint member includes a restraint member body and a coupling member. The restraint member body is arranged circumferentially around the electrode assembly and has a first end and a second end away from the first arc-shaped portion. The first end and the second end are stopped or spaced apart. The coupling member is bonded to the restraint member body and covers the first end and the second end.

[0021] In the above technical solution, by configuring the first restraint member with the above-described structure, the second restraint member can be connected to the restraint member body while the restraint member body is in an unfolded state, before being wound around the electrode assembly. The fastener can then be bonded and fixed to the first and second ends of the restraint member body, thereby assembling the restraint assembly. Because the unfolded restraint member body provides greater operating space, assembly of the second restraint member is more convenient, thereby reducing the overall assembly difficulty of the restraint assembly, lowering manufacturing costs, improving production efficiency, and contributing to improved quality and stability of the restraint assembly.

[0022] In some embodiments of the present application, the restraint body is provided with a receiving groove, and the projections of the first end, the second end and the coupling member on the reference surface are located within the projection of the receiving groove on the reference surface, and in the third direction, the coupling member is at least partially provided in the receiving groove.

[0023] In the above technical solution, the accommodating groove provides space for accommodating the fastener, thereby reducing the thickness of the assembly formed by the fastener and the portion where the restraint body and the fastener are connected, in the third direction. This saves space and allows for the installation of a thicker electrode assembly within the housing assembly, thereby improving the volumetric energy density of the battery cell. Furthermore, the above solution also reduces the material used for the first restraint, lowering manufacturing costs.

[0024] In some embodiments of the present application, in the first direction, the size of the electrode assembly is H1, and the size of the restraining assembly is H2, wherein 90%≤H2 / H1≤101%.

[0025] In the above technical solution, by setting the ratio of the size H2 of the restraint assembly to the size H1 of the electrode assembly within the above range, not only can the restraint assembly have a better restraining effect on the electrode assembly and reduce the risk of breakage of the electrode assembly, but it is also beneficial to reduce the material used in the restraint assembly and reduce costs, thereby better balancing the performance and cost of the restraint assembly.

[0026] In some embodiments of the present application, the thickness of the first restraining member is T1, wherein 0 mm < T1 ≤ 5 mm; the thickness of the second restraining member is T2, wherein 0 mm < T2 ≤ 5 mm.

[0027] In the above technical solution, by setting the thickness T1 of the first restraining member and the thickness T2 of the second restraining member within the above range, the material usage can be reduced and the cost can be reduced while the restraint of the first restraining member and the second restraining member meets the requirements. In addition, the first restraining member and the second restraining member can be at an appropriate thickness, saving the internal space of the shell assembly, which is conducive to increasing the size of the electrode assembly and improving the volume energy density of the battery cell.

[0028] In some embodiments of the present application, the first restraint member has a restraining parameter M1, where 0 N / mm < M1 ≤ 30,000 N / mm. In this technical solution, by setting the restraining parameter M1 of the first restraint member within the aforementioned range, it is advantageous to select a material for the first restraint member with an appropriate restraining force, thereby reducing the likelihood of performance loss due to material selection and thus reducing costs.

[0029] In some embodiments of the present application, 5000 N / mm ≤ M1 ≤ 20000 N / mm. In this technical solution, by further setting the restraint parameter M1 of the first restraint member within the above range, the material selection space for the first restraint member can be narrowed, which is conducive to quickly and accurately finding suitable materials, reducing material selection costs, and facilitating the selection of a first restraint member with better restraint performance.

[0030] In some embodiments of the present application, the second restraining member has a restraining parameter M2, where 0 N / mm < M2 ≤ 5000 N / mm. In this technical solution, by setting the restraining parameter M2 of the second restraining member within the aforementioned range, it is advantageous to select a material for the second restraining member with an appropriate restraining force, thereby reducing the likelihood that a high restraining force of the second restraining member will cause significant internal stress to form within the electrode assembly during the initial stages of cycling. This solution reduces the difficulty in selecting the material for the second restraining member, thereby reducing costs.

[0031] In some embodiments of the present application, 1000 N / mm ≤ M2 ≤ 3000 N / mm. In this technical solution, by further setting the restraint parameter M2 of the second restraint member within the above range, the material selection space for the second restraint member can be narrowed, which is conducive to quickly and accurately finding suitable materials, reducing material selection costs, and facilitating the selection of a second restraint member with appropriate restraint performance.

[0032] In a second aspect, an embodiment of the present application further provides a battery device comprising a battery cell as described in any of the above items.

[0033] In the above technical solution, since the battery cell can effectively alleviate the expansion and deformation of the electrode assembly at the beginning and end of the cycle, the battery cell can have higher reliability, thereby improving the reliability of the battery cell and improving the performance of the battery device.

[0034] In a third aspect, an embodiment of the present application further provides an electrical device, comprising a battery cell as described in any one of the above items; or a battery device as described in the above items.

[0035] In the above technical solution, since the battery cell can effectively alleviate the expansion and deformation of the electrode assembly at the beginning and end of the cycle, the battery cell has a higher reliability, and the electrical device including the battery cell can also have a higher reliability, thereby improving the reliability of the electrical device and improving the performance of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0037] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0038] Figure 2An exploded view of the structure of a battery device provided in some embodiments of the present application;

[0039] Figure 3 An exploded view of a battery cell provided in some embodiments of the present application;

[0040] Figure 4 Cross-sectional view of a battery cell provided in some embodiments of the present application Figure 1 ;

[0041] Figure 5 Provides a schematic diagram of the three-dimensional structure of the restraint assembly for some embodiments of the present application Figure 1 ;

[0042] Figure 6 for Figure 5 A local enlarged schematic diagram of location I;

[0043] Figure 7 Provides a schematic diagram of the three-dimensional structure of the restraint assembly for some embodiments of the present application Figure 2 ;

[0044] Figure 8 Provides a schematic diagram of the three-dimensional structure of the restraint assembly for other embodiments of the present application Figure 1 ;

[0045] Figure 9 for Figure 8 A local enlarged schematic diagram of location II;

[0046] Figure 10 Provides a schematic diagram of the three-dimensional structure of the restraint assembly for other embodiments of the present application Figure 2 ;

[0047] Figure 11 Provides a schematic diagram of the three-dimensional structure of the restraint assembly for some embodiments of the present application Figure 1 ;

[0048] Figure 12 Provides a schematic diagram of the three-dimensional structure of the restraint assembly for some embodiments of the present application Figure 2 ;

[0049] Figure 13 Cross-sectional view of a battery cell provided in some embodiments of the present application Figure 2 .

[0050] icon:

[0051] 1000. Electrical devices;

[0052] 100. Battery device;

[0053] 10. Box body; 11. First box body; 12. Second box body;

[0054] 20. Battery cells;

[0055] 21. Shell assembly;

[0056] 201a, accommodating space; 211, housing; 211a, opening; 212, end cover;

[0057] 22. Electrode assembly;

[0058] 221, first curved portion; 222, first straight portion;

[0059] 23. Binding assembly;

[0060] 231, first restraint;

[0061] 2311, second straight portion;

[0062] 2312, second arc-shaped portion; 2303, first split component; 2304, first connecting component;

[0063] 2313, restraint body; 231a, first end; 231b, second end; 231c, receiving groove;

[0064] 2314, joints;

[0065] 230. Concave part; 2301. First part; 2302. Second part;

[0066] 232, second restraint;

[0067] 2321, main body; 2322, connecting portion; 2323, second split member; 2324, second connecting member;

[0068] 200, controller; 300, motor; Z, first direction; X, second direction; Y, third direction. DETAILED DESCRIPTION

[0069] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0070] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0071] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0072] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0073] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0074] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0075] The term "plurality" used in this application refers to two or more (including two).

[0076] In this application, battery cells may include lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0077] The battery apparatus referred to in the embodiments of this application may refer to a battery assembly comprising one or more battery cells for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or in parallel via a busbar. In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells.

[0078] As an example, the battery cell assembly may be a battery module, which is formed by arranging and fixing multiple battery cells to form an independent module. As an example, the battery module may be formed by bundling multiple battery cells with a cable tie.

[0079] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more battery cell assemblies housed within the housing. For example, the battery cell assemblies may be battery modules, which may be housed within the housing by securing the battery modules within the housing. For example, the battery cell assembly may also be housed within the housing by directly securing multiple battery cells to the housing. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0080] A battery cell includes a casing, an electrode assembly, and an electrolyte. The casing is used to hold the electrode assembly and the electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet consists of a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The negative current collector uncoated with the negative active material layer protrudes from the negative current collector coated with the negative active material layer. The negative current collector uncoated with the negative active material layer serves as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. To ensure that high currents can pass without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together.

[0081] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0082] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and crucial role. A battery consists of a housing and multiple cells housed within it. However, as a core component in new energy vehicles, batteries have high reliability requirements. Improving the reliability of these cells has become a pressing issue.

[0083] In a general battery cell, the electrode assembly will expand significantly in thickness during the first cycle or the first few cycles. The insertion of lithium ions will prop up the negative electrode, causing irreversible expansion of the negative electrode. As the number of cycles increases, the electrode sheet expands more. Therefore, in the later stages of the cycle, the outermost electrode sheet is prone to the risk of being pulled and broken, which in turn affects the reliability of the battery cell.

[0084] Based on the above considerations, and to address the risk of fracture of the outermost electrode sheets due to expansion of the electrode sheets during battery cell cycling, the applicant has designed a battery cell comprising: a housing assembly, an electrode assembly, and a restraining assembly. The housing assembly comprises a housing space; the electrode assembly is in the shape of a coil and disposed within the housing space; the restraining assembly is disposed between the electrode assembly and the housing assembly and comprises a first restraining member and a second restraining member. The first restraining member is disposed circumferentially around the electrode assembly; the second restraining member is disposed between the first restraining member and the electrode assembly and spaced apart from the first restraining member. The second restraining member is disposed circumferentially around the electrode assembly, or the second restraining member is connected to the first restraining member to form an annular member disposed circumferentially around the electrode assembly. The restraining force of the second restraining member is less than that of the first restraining member.

[0085] In a battery cell with this structure, because the restraining force of the second restraining member is less than that of the first restraining member, the second restraining member can exert a certain restraining force on the electrode assembly during the initial period of cyclic expansion, mitigating the rapid expansion of the electrode assembly within a short period of time. This reduces the likelihood of the electrode assembly's electrode plates fracturing due to the high internal stress caused by the large restraining force in the early stages of cycling. In the later stages of cyclic expansion, after the irreversible expansion of the electrode assembly has concluded, the first restraining member can exert a greater restraining force on the electrode assembly, mitigating further expansion in the later stages of cycling. This effectively mitigates electrode expansion and reduces the likelihood of electrode plate fracturing in the later stages of cycling, thereby improving the reliability of the electrode assembly and the battery cell.

[0086] The battery device disclosed in the embodiments of the present application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells, battery devices, etc. disclosed in the present application can be used to form the electrical device.

[0087] The present invention provides an electrical device that uses a battery device as a power source. The electrical device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0088] For the convenience of description, the following embodiments are described by taking an electric device 1000 according to an embodiment of the present application as a vehicle as an example.

[0089] Please refer to Figure 1 , Figure 1A schematic diagram of the structure of a vehicle provided for some embodiments of the present application. 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 vehicle or an extended-range vehicle, etc. A battery device 100 is provided inside the vehicle, and the battery device 100 can be provided at the bottom, head or tail of the vehicle. The battery device 100 can be used to power the vehicle. For example, the battery device 100 can serve as an operating power source for the vehicle. The vehicle can also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to power the motor 300, for example, for starting, navigating and operating power requirements of the vehicle during driving.

[0090] In some embodiments of the present application, the battery device 100 can serve not only as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0091] Please refer to Figure 2 , Figure 2 An exploded view of the structure of a battery device 100 provided in some embodiments of the present application. The battery device 100 includes a housing 10 and a plurality of battery cells 20, which are used to be accommodated in the housing 10. The housing 10 is used to provide an assembly space for the battery cells 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12, the first housing body 11 and the second housing body 12 covering each other, and the first housing body 11 and the second housing body 12 jointly define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-shaped structure, and the first housing body 11 covers the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define an assembly space; the first housing body 11 and the second housing body 12 can also be hollow structures with one side open, and the open side of the first housing body 11 covers the open side of the second housing body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0092] In the battery device 100, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery device 100 can be constructed by first connecting the multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module. The multiple battery modules are then connected in series, in parallel, or in a hybrid configuration to form a single structure, which is then housed within the housing 10. The battery device 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0093] Please refer to Figure 2 , Figure 2 This is a schematic diagram of a partial structure of a battery device 100 provided in some embodiments of the present application. The battery device 100 includes multiple rows of battery cells 20, which are arranged along a first direction X. Each row of battery cells 20 includes multiple battery cells 20 arranged along a second direction Y. The first direction X and the second direction Y are the length and width directions of the housing 10, respectively, and are perpendicular to each other.

[0094] Each battery cell 20 can be a secondary battery or a primary battery, wherein a secondary battery refers to a battery cell 20 that can be activated by charging the active material after the battery cell is discharged and can continue to be used; it can also 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-hydrogen battery, a nickel-cadmium battery, a lead-acid battery, etc., which is not limited in the embodiments of the present application. The battery cell 20 can be cylindrical, flat, rectangular or other shapes. For example, in Figure 2 In FIG, the battery cell 20 is in the shape of a rectangular parallelepiped.

[0095] According to some embodiments of the present application, referring to Figure 3 and Figure 4 An embodiment of the present application provides a battery cell 20 , including: a shell assembly 21 , an electrode assembly 22 and a restraining assembly 23 .

[0096] The housing assembly 21 has a housing space 201a. The electrode assembly 22 is in the shape of a winding core and is disposed within the housing space 201a. The restraint assembly 23 is disposed between the electrode assembly 22 and the housing assembly 21 and includes a first restraint member 231 and a second restraint member 232. The first restraint member 231 is disposed circumferentially around the electrode assembly 22. The second restraint member 232 is disposed between the first restraint member 231 and the electrode assembly 22 and spaced apart from the first restraint member 231. The second restraint member 232 is disposed circumferentially around the electrode assembly 22, or is connected to the first restraint member 231 to form an annular member disposed circumferentially around the electrode assembly 22. The restraint force of the second restraint member 232 is less than that of the first restraint member 231.

[0097] The shell component 21 may refer to a shell structure for wrapping and protecting the chemical materials and components inside the battery. The shape of the shell component 21 may be, but is not limited to, a cuboid, a cube, a cylinder, etc. For example, referring to Figure 3 The shape of the housing component 21 is a rectangular parallelepiped. The material of the housing component 21 can be, but is not limited to, aluminum, iron, steel, etc. As an example, refer to Figure 3 The housing assembly 21 may include a housing 211 and an end cover 212 . The housing 211 is provided with an opening 211 a . The end cover 212 is provided to cover the opening 211 a of the housing 211 .

[0098] The accommodation space 201 a may refer to the space inside the housing assembly 21 for placing the electrode assembly 22 and the electrolyte.

[0099] The electrode assembly 22 may be composed of a positive electrode sheet, a negative electrode sheet, and a separator, and the details can be referred to above. The phrase "the electrode assembly 22 is in a roll-core shape" may be understood to mean that the electrode assembly 22 is a roll-core structure.

[0100] The restraining assembly 23 may refer to a component that fixes and restrains the electrode assembly 22 .

[0101] The first restraint 231 may be an annular member disposed around the circumference of the electrode assembly 22 .

[0102] The second binding member 232 may be an annular member disposed around the circumference of the electrode assembly 22, that is, the second binding member 232 is a small annular member, and the first binding member 231 is a large annular member. The second binding member 232 may also be an annular member connected to the first binding member 231 and forming an annular member with a portion of the first binding member 231 (see Figures 4 to 10 Whether the second restraining member 232 is an annular member itself or forms an annular member in conjunction with a portion of the first restraining member 231, the second restraining member 232 can be disposed closely to the electrode assembly 22 or maintain a small gap with the electrode assembly 22.

[0103] The materials of the first and second restraining members 231, 232 may include, but are not limited to, plastics or composite materials. Plastics may include, but are not limited to, polypropylene, polyethylene, polyamide-imide ester, polycarbonate, thermoplastic elastomer, silicone rubber, and the like. Composite materials may include, but are not limited to, carbon fiber reinforced plastic, glass fiber reinforced plastic, and the like. The first and second restraining members 231, 232 may be made of the same or different materials with different restraining forces.

[0104] As an example, in the above solution, the cross section of the electrode assembly 22 on a plane perpendicular to the first direction Z may be, but is not limited to, a racetrack shape, a rectangle, or a circle. For example, the electrode assembly 22 may be a cylindrical winding core, and correspondingly, the first restraining member 231 and the second restraining member 232 may both be cylindrical components, wherein the diameter of the first restraining member 231 is greater than the diameter of the second restraining member 232. In another example, the electrode assembly 22 may be a racetrack-shaped winding core (see Figure 4 ), the first restraint 231 and the second restraint 232 can both be racetrack-shaped cylindrical parts, wherein the circumferential sides of the first restraint 231 and the second restraint 232 can be spaced at equal distances. In this example, the second restraint 232 can also be two arc-shaped parts, and connect the first restraint 231 to form a ring part (refer to Figure 3 and Figure 4 ).

[0105] Since the restraining force of the second restraining member 232 is smaller than the restraining force of the first restraining member 231, and the second restraining member 232 or the second restraining member 232 and the first restraining member 231 form an annular member surrounding the electrode assembly 22, when the electrode assembly 22 undergoes a large expansion of the electrode piece during the initial first circle or the first few circles of the cycle, the expansion process is irreversible. At this time, the second restraining member 232 can first contact the outermost electrode piece of the electrode assembly 22 and apply a certain amount of restraining force to the electrode piece. The restraining force can slow down the speed of the electrode assembly 22 and reduce the rapid expansion of the electrode assembly 22, thereby relieving the stress inside the electrode assembly 22 and reducing the probability of large internal stress forming inside the electrode assembly 22. This can reduce the risk of the electrode assembly 22 breaking in the early stage of the cycle, thereby improving the reliability of the electrode assembly 22.

[0106] As the electrode assembly 22 continues to cycle, it continues to expand. Because the second restraining member 232 and the first restraining member 231 are spaced apart, leaving a gap between them, the electrode assembly 22 stretches the second restraining member 232. During this process, the second restraining member 232 consistently suppresses significant expansion of the electrode assembly 22. Once the irreversible expansion of the electrode assembly 22 ends, the expansion of the electrode assembly 22 during subsequent cycles becomes reversible. As the electrode assembly 22 gradually expands, the second restraining member 232 comes into contact with the first restraining member 231. At this point, the first restraining member 231 provides a stronger restraining force than the second restraining member 232. During subsequent long-term cycling, the second restraining member 232 exerts a strong restraining force on the electrode assembly 22 without breaking, suppressing further expansion of the electrode assembly 22 and further slowing its expansion during later cycles until the electrode pieces of the electrode assembly 22 break when subjected to a maximum tensile force. In other words, the first restraining member 231 reduces the probability of fracture in the electrode assembly 22.

[0107] It is understandable that, with respect to the problem in the related art that the electrode assembly is prone to fracture due to expansion during the cycle, if a single restraining member is used to provide a larger restraining force to suppress the expansion of the electrode assembly, the electrode assembly is prone to rapid expansion in a short period of time at the initial stage of the cycle, resulting in greater internal stress, which in turn makes the electrode assembly at risk of fracture at the initial stage of the cycle, affecting the reliability and life of the battery cell.

[0108] In the above technical solution, because the restraining force of the second restraining member 232 is less than that of the first restraining member 231, the second restraining member 232 can exert a certain restraining force on the electrode assembly 22 during the initial period of cyclic expansion of the electrode assembly 22, thereby alleviating the rapid expansion of the electrode assembly 22 in a short period of time. This reduces the probability of the electrode assembly 22 fracturing due to the large internal stress caused by the large restraining force in the early period of the cycle. In the later period of cyclic expansion of the electrode assembly 22, after the irreversible expansion of the electrode assembly 22 has concluded, the first restraining member 231 can exert a greater restraining force on the electrode assembly 22, mitigating the continued expansion of the electrode assembly 22 in the later period of the cycle. This effectively alleviates the electrode expansion problem, reduces the probability of electrode fracturing in the electrode assembly 22 in the later period of the cycle, and improves the reliability of the electrode assembly 22 and the reliability of the battery cell 20.

[0109] In some embodiments of the present application, reference is made to Figure 3 and Figure 4 The electrode assembly 22 includes a first arc-shaped portion 221 , and the second restraining member 232 is spaced apart from the first restraining member 231 on at least one side away from the first arc-shaped portion 221 .

[0110] The first arc portion 221 may refer to an arc-shaped portion of the electrode assembly 22. As an example, the cross section of the electrode assembly 22 perpendicular to the second direction X and the third direction Y may be circular, in which case the electrode assembly 22 may only include the first arc portion 221. As an example, the cross section of the electrode assembly 22 perpendicular to the second direction X and the third direction Y may also be runway-shaped, in which case the electrode assembly 22 may include other portions in addition to the first arc portion 221, such as the first straight portion 222 (see FIG. Figure 3 and Figure 4 As an example, the cross section of the electrode assembly 22 perpendicular to the second direction X and the third direction Y may also be a rectangle, with the four corners of the rectangle forming a first curved portion 221. That is, the electrode assembly 22 includes not only the first curved portion 221 and the first straight portion 222, but may also include other straight portions.

[0111] The above is just an example and is not limited to this embodiment.

[0112] The phrase "the second restraining member 232 is spaced apart from the first restraining member 231 on at least one side facing away from the first curved portion 221" can be understood to mean that the second restraining member 232 may be spaced apart from the first restraining member 231 around the circumference of the electrode assembly 22. Alternatively, the second restraining member 232 may be spaced apart from the first restraining member 231 only in the portion corresponding to the first curved portion 221. This is not specifically limited in the above embodiment.

[0113] In the battery cell 20, when the pole piece of the electrode assembly 22 expands, the pole piece will be subjected to a pulling force, and the first arc portion 221 will be more likely to produce stress concentration than other areas of the electrode assembly 22 due to changes in local stiffness. The probability of the pole piece where the first arc portion 221 is located being broken is also higher.

[0114] In the above technical solution, since the first curved portion 221 is the portion of the electrode assembly 22 with a higher probability of fracture, the second restraining member 232 is spaced apart from the first restraining member 231 on at least one side facing away from the first curved portion 221. Thus, the second restraining member 232 can apply a smaller restraining force to the first curved portion 221 in the early stages of the cycle of the electrode assembly 22, slowing the expansion rate of the first curved portion 221 and alleviating the short-term rapid expansion of the first curved portion 221, thereby reducing the risk of fracture of the electrode segment at the location of the first curved portion 221 in the early stages of the cycle. The first restraining member 231 can apply a larger restraining force to the first curved portion 221 in the late stages of the cycle of the electrode assembly 22, alleviating the expansion of the electrode segment at the location of the first curved portion 221, thereby reducing the amount of expansion and deformation of the electrode segment at the location of the first curved portion 221 in the late stages of the cycle and reducing the risk of fracture of the first curved portion 221. That is to say, the above solution can reduce the risk of fracture of the electrode segment at the position of the first arc portion 221 in the electrode assembly 22, which is beneficial to reduce the risk of fracture of the entire electrode assembly 22, improve the reliability of the electrode assembly 22, and further improve the reliability of the battery cell 20.

[0115] In some embodiments of the present application, reference is made to Figure 3 and Figure 4 The electrode assembly 22 has a first direction Z, a second direction X and a third direction Y that are perpendicular to each other. The electrode assembly 22 is wound around the first direction Z. The electrode assembly 22 includes a first straight portion 222. The first straight portion 222 is located at both ends of the second direction X and is provided with a first arc-shaped portion 221. The second restraining member 232 is arranged corresponding to the first arc-shaped portion 221, and is located at both ends of the third direction Y and is connected to the first restraining member 231.

[0116] The first straight portion 222 may refer to the straight portion of the electrode assembly 22, that is, the portion corresponding to the large surface of the winding core. The first straight portion 222 is provided with first arc-shaped portions 221 at both ends of the second direction X. Figure 4 The electrode assembly 22 has a racetrack shape in a cross section perpendicular to the second direction X and the third direction Y.

[0117] "The second binding member 232 is provided corresponding to the first arc portion 221 and is located at both ends of the third direction Y and connected to the first binding member 231", refer to Figure 3 and Figure 4 The second restraining members 232 are arranged at both ends of the first arc-shaped portion 221 in the second direction X. The second restraining members 232 are connected to the first restraining members 231 to form an annular member, thereby being arranged around the circumference of the electrode assembly 22.

[0118] In the above technical solution, the electrode assembly 22 adopts the aforementioned square structure, thereby allowing the battery cells 20 to be oriented as a whole, which is beneficial for improving the battery energy density when the battery cells 20 form the battery device 100. Because the first straight portion 222 has a lower risk of fracture than the first curved portion 221, the second restraining member 232 is configured in the above structure. While reducing the risk of fracture of the entire electrode assembly 22, the wall thickness of the restraining assembly 23 in the third direction Y can be reduced, thereby reducing the size of the battery cells 20 in the third direction, which is beneficial for improving the energy density of the battery cells 20.

[0119] In some embodiments of the present application, reference is made to Figure 4 The second restraining member 232 is arc-shaped and is spaced apart from the first arc-shaped portion 221 .

[0120] In the above technical solution, the second restraining member 232 is arc-shaped, matching the shape of the first curved portion 221. Consequently, upon contact with the first curved portion 221, the second restraining member 232 can better adhere to the surface of the first curved portion 221. The restraining force of the second restraining member 232 can be more evenly distributed across the first curved portion 221, providing a more balanced restraining effect and thereby alleviating expansion and deformation of the first curved portion 221. The second restraining member 232 is spaced apart from the first curved portion 221, eliminating the need for restraining force on the first curved portion 221 during the initial cycling of the electrode assembly 22. This facilitates stress relief for the first curved portion 221 during the initial cycling phase, reduces the likelihood of fracture due to internal stress caused by the restraining force during the rapid expansion of the first curved portion 221 during the initial cycling phase, and further improves the reliability of the electrode assembly 22.

[0121] In some embodiments of the present application, reference is made to Figures 5 to 7 The second restraining member 232 includes a main body 2321 and a connecting portion 2322. The main body 2321 is located at both ends of the third direction Y and is provided with a plurality of connecting portions 2322. The plurality of connecting portions 2322 are arranged at intervals along the first direction Z; the first restraining member 231 is located at both ends of the third direction Y and is provided with a plurality of recesses 230. The plurality of recesses 230 and the plurality of connecting portions 2322 correspond one to one, and part of the connecting portion 2322 is arranged in the recess 230.

[0122] The main body portion 2321 may refer to the main structure of the second restraining member 232 and may be an arc-shaped sheet component.

[0123] The connecting portion 2322 may be a connecting component for connecting the main body 2321 and the first restraining member 231. The connecting portion 2322 may be a long strip extending along the arc length of the second restraining member 232. The cross-section of the connecting portion 2322 may be, but is not limited to, rectangular, circular, or the like.

[0124] The recess 230 may refer to a recessed area with a certain size provided on the first binding member 231. The recess 230 may be, but is not limited to, a slot or a hole.

[0125] In the above technical solution, when the first curved portion 221 expands along the second direction X and gradually stretches the second restraining member 232 until it contacts the first restraining member 231, the second restraining member 232 contacts the first restraining member 231 at both ends in the third direction Y. At this point, the recessed portion 230 provides space for accommodating the connecting portion 2322, which helps reduce the overall wall thickness of the restraining assembly 23 in the third direction Y, saving space within the housing assembly 21. This provides more space for the electrode assembly 22 in the third direction Y, thereby increasing the volume of the electrode assembly 22 and improving the volumetric energy density of the battery cell 20. The second restraining member 232 is configured to include a main portion 2321 and a plurality of connecting portions 2322. While achieving the above-mentioned effects, it also provides a certain degree of rigidity for the second restraining member 232, reducing the risk of deformation and improving the reliability of the structure. The main body 2321 is connected to the multiple recesses 230 of the first restraint member 231 through multiple connecting parts 2322. This can improve the connection reliability between the second restraint member 232 and the first restraint member 231, and improve the overall rigidity of the restraint assembly 23, reduce the risk of deformation of the restraint assembly 23 during assembly, and help improve the installation stability of the restraint assembly 23, and facilitate the assembly of the restraint assembly 23 into the shell assembly 21.

[0126] In some embodiments of the present application, reference is made to Figures 5 to 7 The first restraining member 231 includes a second straight portion 2311 and a second curved portion 2312. The second curved portion 2312 is arranged at both ends of the second straight portion 2311 in the second direction X. The recess 230 includes a first part 2301 and a second part 2302 that are connected. The first part 2301 is arranged on the second straight portion 2311, and the second part 2302 is arranged on the second curved portion 2312.

[0127] The second straight portion 2311 may refer to a straight portion of the first binding member 231. The second curved portion 2312 may refer to a curved portion of the first binding member 231.

[0128] “The recess 230 includes a first part 2301 and a second part 2302 that are connected to each other”, which can be understood as the recess 230 is a recessed area that is longer in the second direction X, and a part of it is arranged on the second straight part 2311, and the other part is arranged on the second curved part 2312, and the connecting part 2322 that cooperates with the recess 230 can also have a larger length.

[0129] In the above technical solution, the first restraining member 231 is configured in the above-described structure, so that the shape of the first restraining member 231 matches the shape of the electrode assembly 22. When the first curved portion 221 expands the second restraining member 232 and contacts the first restraining member 231, the second curved portion 2312, the second restraining member 232, and the first curved portion 221 are tightly fitted together, thereby evenly distributing the restraining force of the second restraining member 232 on the first curved portion 221. This provides a better restraining effect on the first curved portion 221, further alleviating the expansion and deformation of the first curved portion 221 during the later stages of the cycle of the electrode assembly 22, and reducing the probability of fracture of the electrode assembly 22. The above-described structure of the recess 230 increases the storage space of the recess 230, and provides a longer connecting portion 2322, reducing the overall thickness of the restraining assembly 23 in the second direction X, further saving space. This allows for the placement of a larger electrode assembly 22 within the housing assembly 21, further improving the volumetric energy density of the battery cell 20.

[0130] In some embodiments of the present application, reference is made to Figure 5 and Figure 6 The first restraining member 231 includes a second straight portion 2311 and a second curved portion 2312. The second curved portion 2312 is arranged at both ends of the second straight portion 2311 in the second direction X. At least one of the second curved portions 2312 located at both ends of the second direction X includes a first split member 2303 and a first connecting member 2304. There are two first split members 2303, and they are adjacent to each other in the third direction Y. The first connecting member 2304 is bonded to the two first split members 2303.

[0131] It is understandable that the second arc portion 2312 can be composed of two first split parts 2303 connected by a first joint part 2304, wherein the sizes of the two first split parts 2303 can be the same or different. Figure 6 The first split component 2303 can be a long strip component extending along the first direction.

[0132] The first connecting member 2304 may be an adhesive component used to connect the two first split members 2303. The first connecting member 2304 may be, but is not limited to, an adhesive tape or the like.

[0133] “At least one of the second arc-shaped portions 2312 located at both ends of the second direction X includes a first split part 2303 and a first joining part 2304”, it can be understood that the second arc-shaped portions 2312 at both ends of the second direction X may refer to one including a first split part 2303 and a first joining part 2304; the second arc-shaped portions 2312 at both ends of the second direction X may also both include a first split part 2303 and a first joining part 2304, and no specific limitation is made in this embodiment.

[0134] In the above technical solution, by setting the second arc-shaped portion 2312 into the above structure, the second restraint member 232 can be installed into the first restraint member 231 before the first coupling member 2304 and the two first split members 2303 are assembled. This can provide a larger space for the installation of the second restraint member 232, facilitate assembly, reduce the difficulty of installing the second restraint member 232, improve assembly and production efficiency, and also help to improve the quality stability of the restraint assembly 23.

[0135] In some embodiments of the present application, reference is made to Figure 5 and Figure 6 At least one of the second restraining members 232 located at both ends of the second direction X includes a second split member 2323 and a second connecting member 2324. There are two second split members 2323, and they are adjacently arranged in the third direction Y. The second connecting member 2324 is bonded and connected to the two second split members 2323.

[0136] It is understood that the second restraining member 232 can be composed of two second split members 2323 connected by a second joint member 2324, wherein the sizes of the two second split members 2323 can be the same or different. Figure 6 The second split component 2323 can be a long strip component extending along the first direction.

[0137] The second connecting member 2324 may be an adhesive component used to connect the two second split members 2323. The second connecting member 2324 may be, but is not limited to, an adhesive tape or the like.

[0138] "At least one of the second restraining members 232 located at both ends of the second direction X includes a second split member 2323 and a second connecting member 2324." It can be understood that the second restraining members 232 at both ends of the second direction X may refer to one including a second split member 2323 and a second connecting member 2324; the second restraining members 232 at both ends of the second direction X may also both include a second split member 2323 and a second connecting member 2324, and no specific limitation is made in this embodiment.

[0139] In the above technical solution, by setting the second restraining member 232 into the above structure, the two second split members 2323 can be connected to the first restraining member 231 respectively, and then the two second split members 2323 can be connected together through the second connecting member 2324. This can reduce the difficulty of installing the second restraining member 232 within the limited space of the first restraining member 231, improve assembly and production efficiency, and is also beneficial to improving the quality stability of the restraining component 23.

[0140] In some embodiments of the present application, reference is made to Figures 8 to 10The first restraint member 231 includes a restraint member body 2313 and a coupling member 2314. The restraint member body 2313 is arranged around the circumference of the electrode assembly 22 and has a first end 231a and a second end 231b away from the first arc-shaped portion 221. The first end 231a and the second end 231b are stopped or spaced apart. The coupling member 2314 is bonded to the restraint member body 2313 and covers the first end 231a and the second end 231b.

[0141] The restraint member body 2313 may refer to the main structure of the first restraint member 231. In the above example, the restraint member body 2313 may be a sheet-like component that wraps around the electrode assembly 22. The first end 231a and the second end 231b may refer to the two ends of the sheet-like component when it is unfolded. After the sheet-like component wraps around the electrode assembly 22, the first end 231a and the second end 231b may abut against each other or be spaced apart at a predetermined distance.

[0142] The joint member 2314 may be a component that securely connects the wound binding member body 2313. The joint member 2314 may be a component with adhesive, for example, an adhesive tape.

[0143] In the above technical solution, by configuring the first restraint member 231 with the above-described structure, the second restraint member 232 can be connected to the restraint member body 2313 when the restraint member body 2313 is in an unfolded state, before being wound around the electrode assembly 22. The joining member 2314 can then be bonded and fixed to the first end 231a and the second end 231b of the restraint member body 2313, thereby assembling the restraint assembly 23. Since the restraint member body 2313 has a larger operating space when unfolded, the second restraint member 232 can be more easily assembled, thereby reducing the overall assembly difficulty of the restraint assembly 23, lowering manufacturing costs, improving production efficiency, and facilitating improved quality and stability of the restraint assembly 23.

[0144] In some embodiments of the present application, reference is made to Figure 11 and Figure 12 The restraint body 2313 is provided with a receiving groove 231c, which serves as a reference surface parallel to the first direction Z and the second direction X. The projections of the first end 231a, the second end 231b and the coupling 2314 on the reference surface are located within the projection of the receiving groove 231c on the reference surface, and in the third direction Y, the coupling 2314 is at least partially located in the receiving groove 231c.

[0145] The receiving groove 231c may refer to a groove formed on the surface of the restraint body 2313. The receiving groove 231c may be located on the inner or outer side of the restraint body 2313. The receiving groove 231c may extend through the restraint body 2313 along the first direction Z. Alternatively, the receiving groove 231c may be smaller than the restraint body 2313 in the first direction Z. For example, there may be multiple engaging members 2314, spaced apart along the first direction Z. This embodiment does not impose any specific limitations on the above arrangement.

[0146] "Serve as a reference plane parallel to the first direction Z and the second direction X, and the projections of the first end 231a, the second end 231b and the coupling 2314 on the reference plane are located within the projection of the accommodating groove 231c on the reference plane." This can be understood as the first end 231a, the second end 231b and the coupling 2314 are all located within the section of the restraint body 2313 where the accommodating groove 231c is set.

[0147] "In the third direction Y, the coupling 2314 is at least partially disposed in the accommodating groove 231c" can be understood as, in the third direction Y, the thickness of the coupling 2314 may be greater than the groove depth of the accommodating groove 231c, in which case, part of the coupling 2314 is located in the accommodating groove 231c; or, the thickness of the coupling 2314 is less than or equal to the groove depth of the accommodating groove 231c, in which case the outer surface of the coupling 2314 does not exceed the surface of the restraint body 2313.

[0148] In the above technical solution, the accommodating groove 231c provides space for accommodating the connecting member 2314, thereby reducing the thickness of the assembly formed by the connecting member 2314 and the portion connected to the connecting member 2314 in the third direction Y. This saves space and allows for a thicker electrode assembly 22 to be installed within the housing assembly 21, thereby improving the volumetric energy density of the battery cell 20. Furthermore, the above solution also reduces the material used for the first restraining member 231, thereby lowering manufacturing costs.

[0149] In some embodiments of the present application, reference is made to Figure 12 In the third direction Y, the dimensions of the joint 2314 are equal to the dimensions of the receiving groove 231c. In other words, the thickness of the joint 2314 is equal to the depth of the receiving groove 231c. This prevents the joint 2314 from protruding beyond the receiving groove 231c and occupying space within the housing assembly 21, thereby increasing the size of the electrode assembly 22 and improving the energy density of the battery cell 20. Furthermore, the joint 2314 can be made thicker, thereby providing greater rigidity, thereby improving the reliability of the joint 2314's connection to the restraint body 2313 and enhancing the overall reliability of the first restraint 231.

[0150] In some embodiments of the present application, reference is made to Figure 12 In the first direction Z, the receiving groove 231c penetrates the restraining member body 2313. It can be understood that, with this solution, the receiving groove 231c has a larger size. Accordingly, the size of the engaging member 2314 in the first direction Z can be made larger, thereby providing a larger engagement surface with the restraining member body 2313. This can improve the connection reliability of the engaging member 2314 to the restraining member body 2313 and enhance the overall stability of the first restraining member 231.

[0151] In some embodiments of the present application, reference is made to Figure 13 In the first direction Z, the size of the electrode assembly 22 is H1, and the size of the restraining assembly 23 is H2, wherein 90%≤H2 / H1≤101%.

[0152] H2 / H1 can be, but is not limited to, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, 100%, 101%, and so on. If H2 / H1 is less than 90%, the restraining surface area of the restraining assembly 23 on the electrode assembly 22 in the first direction Z is small, which is not conducive to a more comprehensive restraining effect and increases the risk of expansion and fracture of the electrode assembly 22. If H2 / H1 is greater than 101%, the restraining surface area of the restraining assembly 23 on the electrode assembly 22 in the first direction Z is large, resulting in wasted performance of the restraining assembly 23, increased material consumption of the restraining assembly 23, and thus increased cost.

[0153] In the above technical solution, by setting the ratio of the size H2 of the restraint component 23 and the size H1 of the electrode component 22 within the above range, not only can the restraint component 23 have a better restraining effect on the electrode component 22 and reduce the risk of breakage of the electrode component 22, but it is also beneficial to reduce the material used in the restraint component 23 and reduce the cost, thereby better balancing the performance and cost of the restraint component 23.

[0154] In some embodiments of the present application, reference is made to Figure 4 The thickness of the first restraining member 231 is T1, wherein 0mm<T1≤5mm; the thickness of the second restraining member 232 is T2, wherein 0mm<T2≤5mm.

[0155] The thickness T1 of the first tie 231 may be, but is not limited to, 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or the like.

[0156] The thickness T2 of the second restraining member 232 may be, but is not limited to, 0.1 mm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, etc. The thickness T2 of the second restraining member 232 may be equal to or different from the thickness T1 of the first restraining member 231 .

[0157] The thickness T1 of the first restraining member 231 and the thickness T2 of the second restraining member 232 can be appropriately selected based on the size of the electrode assembly 22. If the thickness T1 of the first restraining member 231 and the thickness T2 of the second restraining member 232 are greater than 5 mm, the restraining force of the first restraining member 231 and the second restraining member 232 will be too large, resulting in performance loss and increased material costs.

[0158] In the above technical solution, by setting the thickness T1 of the first restraining member 231 and the thickness T2 of the second restraining member 232 within the above range, the material usage can be reduced and the cost can be reduced while the restraint of the first restraining member 231 and the second restraining member 232 meets the requirements. In addition, the first restraining member 231 and the second restraining member 232 can be at an appropriate thickness, saving the internal space of the shell assembly 21, which is conducive to increasing the size of the electrode assembly 22 and improving the volume energy density of the battery cell 20.

[0159] In some embodiments of the present application, the restraining parameter of the first restraining member 231 is M1, wherein 0 N / mm<M1≤30000 N / mm.

[0160] The restraint parameter M1 can be understood as the force required for the first restraint member 231 to be exerted for every 1 mm increase in the second direction X or the third direction Y. M1 can be, but is not limited to, 1000 N / mm, 2000 N / mm, 3000 N / mm, 4000 N / mm, 5000 N / mm, 6000 N / mm, 7000 N / mm, 8000 N / mm, 12000 N / mm, 15000 N / mm, 20000 N / mm, 21000 N / mm, 24000 N / mm, 28000 N / mm, 30000 N / mm, and the like.

[0161] In the above technical solution, by setting the binding parameter M1 of the first binding member 231 within the above range, it is helpful to select the material of the first binding member 231 with appropriate binding force, which can reduce the probability of performance waste caused by material selection and help reduce costs.

[0162] In some embodiments of the present application, 5000 N / mm≤M1≤20000 N / mm.

[0163] It can be understood that M1 can be but is not limited to 5000N / mm, 5500N / mm, 5800N / mm, 6200N / mm, 6500N / mm, 7500N / mm, 8500N / mm, 9500N / mm, 10500N / mm, 11000N / mm, 11500N / mm, 12500N / mm, 15500N / mm, 17500N / mm, 18000N / mm, 18500N / mm, 19500N / mm and the like.

[0164] In the above technical solution, by further setting the binding parameter M1 of the first binding member 231 within the above range, the selection space of the material of the first binding member 231 can be narrowed, which is conducive to quickly and accurately finding suitable materials, reducing material selection costs, and facilitating the selection of a first binding member 231 with better binding force performance.

[0165] In some embodiments of the present application, the restraining parameter of the second restraining member 232 is M2, wherein 0 N / mm<M2≤5000 N / mm.

[0166] The restraint parameter M2 can be understood as the force required for the second restraint member 232 to be applied for every 1 mm increase in the second direction X or the third direction Y. M2 can be, but is not limited to, 1000 N / mm, 1500 N / mm, 2000 N / mm, 2500 N / mm, 3000 N / mm, 3500 N / mm, 4000 N / mm, 4500 N / mm, 5000 N / mm, and the like.

[0167] In the above technical solution, by setting the binding parameter M2 of the second binding member 232 within the above range, it is beneficial to select the material of the second binding member 232 with appropriate binding force, and reduce the probability that the second binding member 232 has a larger binding force, which will cause the electrode assembly 22 to form a larger internal stress in the early stage of the cycle. The above solution can reduce the difficulty of selecting the material of the second binding member 232, which is beneficial to reducing costs.

[0168] In some embodiments of the present application, 1000 N / mm≤M2≤3000 N / mm.

[0169] It can be understood that M2 can be but is not limited to 1000N / mm, 1200N / mm, 1400N / mm, 1600N / mm, 1800N / mm, 2000N / mm, 2200N / mm, 2400N / mm, 2600N / mm, 2800N / mm, 3000N / mm and the like.

[0170] In the above technical solution, by further setting the binding parameter M2 of the second binding member 232 within the above range, the selection space of the material of the second binding member 232 can be narrowed, which is conducive to finding suitable materials quickly and accurately, reducing the material selection cost, and is conducive to selecting a second binding member 232 with suitable binding force performance.

[0171] In some embodiments of the present application, the second restraining member 232 is configured to break when subjected to a set tensile force. That is, when the first curved portion 221 of the electrode assembly 22 continues to expand and stretch the second restraining member 232 at the beginning of the cycle, the second restraining member 232 can break to reduce the restraining force on the first curved portion 221. This further reduces the probability of the electrode piece breaking due to the high internal stress within the first curved portion 221 during the initial cycle, thereby further improving the reliability of the electrode assembly 22 and, by extension, the battery cell 20.

[0172] Example 1

[0173] Reference Figures 3 and 4 According to an embodiment of the present application, a battery cell 20 includes a shell assembly 21 , an electrode assembly 22 and a restraining assembly 23 .

[0174] The housing assembly 21 has an accommodating space 201 a .

[0175] The electrode assembly 22 is in the shape of a winding core and is arranged in the accommodating space 201a. It has a first direction Z, a second direction X and a third direction Y that are perpendicular to each other. The electrode assembly 22 is wound around the first direction Z. The electrode assembly 22 includes a first arc-shaped portion 221 and a first straight portion 222. The first straight portion 222 is located at both ends of the second direction X and has a first arc-shaped portion 221.

[0176] The restraining assembly 23 is arranged between the electrode assembly 22 and the shell assembly 21, and includes a first restraining member 231 and a second restraining member 232. The first restraining member 231 is arranged circumferentially around the electrode assembly 22, and the second restraining member 232 is arranged between the first restraining member 231 and the electrode assembly 22, and is arranged at both ends of the first restraining member 231 in the second direction X. The second restraining member 232 is arc-shaped and is spaced apart from the first arc-shaped portion 221. The second restraining member 232 is spaced apart from the first restraining member 231 on the side away from the first arc-shaped portion 221.

[0177] The second restraining member 232 includes a main body 2321 and a connecting portion 2322. The main body 2321 is located at both ends of the third direction Y and is provided with a plurality of connecting portions 2322. The plurality of connecting portions 2322 are in the shape of long strips and are arranged at intervals along the first direction Z. The first restraining member 231 is located at both ends of the third direction Y and is provided with a plurality of through holes. The plurality of through holes are in the shape of long strips and correspond one-to-one to the plurality of connecting portions 2322. Part of the connecting portion 2322 is arranged in the through holes.

[0178] The first restraining member 231 includes a second straight portion 2311 and a second curved portion 2312. The second curved portion 2312 is arranged at both ends of the second straight portion 2311 in the second direction X. The second curved portion 2312 located at one end of the second direction X includes a first split member 2303 and a first connecting member 2304. There are two first split members 2303, and they are adjacent to each other in the third direction Y. The first connecting member 2304 is a tape and is adhesively connected to the two first split members 2303.

[0179] The second restraining member 232 at one end in the second direction X includes a second split member 2323 and a second connecting member 2324 . There are two second split members 2323 , which are adjacently arranged in the third direction Y. The second connecting member 2324 is a tape, which is bonded to the two second split members 2323 .

[0180] Example 2

[0181] Reference Figure 3 、 Figure 4 、 Figures 8 to 10 The structure of the battery cell 20 of the second embodiment is substantially the same as that of the battery cell 20 of the first embodiment, except that the first restraint 231 includes a restraint body 2313 and a coupling 2314. The restraint body 2313 is arranged circumferentially around the electrode assembly 22 and has a first end 231a and a second end 231b away from the first arc-shaped portion 221. The first end 231a and the second end 231b are abutted or spaced apart. The coupling 2314 is a tape that adheres to the restraint body 2313 and covers the first end 231a and the second end 231b.

[0182] Example 3

[0183] Reference Figure 3 、 Figure 4 、 Figure 11 and Figure 12 The structure of the battery cell 20 of the third embodiment is substantially the same as that of the battery cell 20 of the second embodiment, except that the restraint body 2313 is provided with a receiving groove 231c, which serves as a reference surface parallel to the first direction Z and the second direction X. The projections of the first end 231a, the second end 231b, and the coupling member 2314 on the reference surface are located within the projection of the receiving groove 231c on the reference surface. In the third direction Y, the coupling member 2314 is disposed within the receiving groove 231c.

[0184] The embodiment of the present application further provides a battery device 100 , comprising a battery cell 20 as described in any of the above items.

[0185] In the above technical solution, since the battery cell 20 can effectively alleviate the expansion and deformation of the electrode assembly 22 at the beginning and end of the cycle, the battery cell 20 can have higher reliability, thereby improving the reliability of the battery cell 20 and helping to improve the performance of the battery device 100.

[0186] The embodiment of the present application further provides an electric device 1000 , comprising the battery cell 20 as described above; or the battery device 100 as described above.

[0187] In the above technical solution, since the battery cell 20 can effectively alleviate the expansion and deformation of the electrode assembly 22 at the beginning and end of the cycle, the battery cell 20 has a higher reliability, and the battery device 100 including the battery cell 20 also has a higher reliability, thereby improving the reliability of the power device 1000 and improving the performance of the power device 1000.

[0188] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0189] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: A housing assembly having a receiving space; an electrode assembly in a coiled core shape and disposed in the accommodation space; A restraining assembly is arranged between the electrode assembly and the shell assembly, and includes a first restraining member and a second restraining member. The first restraining member is arranged around the circumference of the electrode assembly, and the second restraining member is arranged between the first restraining member and the electrode assembly and spaced apart from the first restraining member. The second restraining member is arranged around the circumference of the electrode assembly, or the second restraining member is connected to the first restraining member to form an annular member arranged around the circumference of the electrode assembly, and the restraining force of the second restraining member is less than the restraining force of the first restraining member.

2. The battery cell according to claim 1, wherein: The electrode assembly includes a first arc-shaped portion, and the second restraining member is spaced apart from the first restraining member at least on one side facing away from the first arc-shaped portion.

3. The battery cell according to claim 2, characterized in that: The electrode assembly has a first direction, a second direction and a third direction that are perpendicular to each other. The electrode assembly is wound around the first direction. The electrode assembly includes a first straight portion, and the first straight portion is provided with the first arc-shaped portion at both ends of the second direction. The second restraining member is provided corresponding to the first arc-shaped portion, and is connected to the first restraining member at both ends of the third direction.

4. The battery cell according to claim 3, characterized in that The second restraining member is arc-shaped and spaced apart from the first arc-shaped portion.

5. The battery cell according to claim 3 or 4, characterized in that: The second restraining member includes a main body and a connecting part, and the main body is provided with multiple connecting parts at both ends of the third direction, and the multiple connecting parts are arranged at intervals along the first direction; the first restraining member is provided with multiple recesses at both ends of the third direction, and the multiple recesses correspond to the multiple connecting parts one by one, and part of the connecting part is arranged in the recess.

6. The battery cell according to claim 5, characterized in that The first restraining member includes a second straight portion and a second curved portion, the second curved portions are arranged at both ends of the second straight portion in the second direction, and the recess includes a first part and a second part that are connected, the first part is arranged on the second straight portion, and the second part is arranged on the second curved portion.

7. The battery cell according to claim 3, characterized in that The first restraining member includes a second straight portion and a second curved portion, the second curved portion is arranged at both ends of the second straight portion in the second direction, at least one of the second curved portions located at both ends of the second direction includes a first split member and a first joining member, there are two first split members, and they are adjacently arranged in the third direction, and the first joining member is bonded to the two first split members.

8. The battery cell according to claim 3, characterized in that At least one of the second restraining members located at both ends of the second direction includes a second split member and a second joining member. There are two second split members, which are adjacently arranged in the third direction. The second joining member is bonded to the two second split members.

9. The battery cell according to claim 3, characterized in that: The first restraining member includes a restraining member body and a coupling member. The restraining member body is arranged around the circumference of the electrode assembly and has a first end and a second end away from the first arc-shaped portion. The first end and the second end are stopped or spaced apart. The coupling member is bonded to the restraining member body and covers the first end and the second end.

10. The battery cell according to claim 9, characterized in that The restraint body is provided with a receiving groove, which serves as a reference surface parallel to the first direction and the second direction. The first end, the second end and the projection of the coupling member on the reference surface are located within the projection of the receiving groove on the reference surface, and in the third direction, the coupling member is at least partially arranged in the receiving groove.

11. The battery cell according to any one of claims 3, 4, 6 to 10, characterized in that: In the first direction, the size of the electrode assembly is H1, and the size of the restraining assembly is H2, wherein 90%≤H2 / H1≤101%.

12. The battery cell according to any one of claims 1 to 4 and 6 to 10, characterized in that: The thickness of the first restraining member is T1, wherein 0 mm < T1 ≤ 5 mm; The thickness of the second restraining member is T2, wherein 0mm<T2≤5mm.

13. The battery cell according to any one of claims 1 to 4 and 6 to 10, characterized in that: The restraining parameter of the first restraining member is M1, wherein 0 N / mm<M1≤30000 N / mm.

14. The battery cell according to claim 13, characterized in that 5000N / mm≤M1≤20000N / mm.

15. The battery cell according to claim 13, characterized in that The restraining parameter of the second restraining member is M2, wherein 0 N / mm<M2≤5000 N / mm.

16. The battery cell according to claim 15, characterized in that 1000N / mm≤M2≤3000N / mm.

17. A battery device, characterized in that: The invention comprises the battery cell according to any one of claims 1 to 16.

18. An electrical device, characterized in that: Comprising the battery cell according to any one of claims 1 to 16; or the battery device according to claim 17.

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