Battery monomer, battery device and electric device

Abstract

The utility model discloses a battery monomer, a battery device and a power utilization device, the battery monomer comprises a shell, an electrode assembly and a supporting structure, the electrode assembly is arranged in the shell and comprises at least one winding type pole group, the peripheral surface of the winding type pole group comprises a plane part and a curved surface part, in the circumferential direction of the winding type pole group, the plane part extends along a straight line, and the curved surface part extends along a straight line; the curved surface part extends along a curve, the supporting structure is arranged in the shell and located between the peripheral side of the winding type pole group and the shell, at least part of the supporting structure is located between the curved surface part and the shell, the surface, facing the winding type pole group, of the supporting structure forms a restraining surface, and the restraining surface makes contact with or is connected with the curved surface part. According to the battery monomer disclosed by the embodiment of the invention, the supporting structure is arranged in the shell, and at least part of the supporting structure is positioned between the curved surface part of the winding type pole group and the shell, so that expansion deformation constraint on the curved surface part can be increased, the possibility of cracking of the pole piece corresponding to the curved surface part is reduced, and the reliability and the safety of the battery monomer are improved.

Description

Technical Field

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

[0002] In the related art, a battery cell includes a housing and an electrode assembly disposed inside the housing. The electrode assembly includes at least one wound electrode group, and the wound electrode group is formed by laminating and winding a positive electrode sheet, a negative electrode sheet, and a separator. The outer peripheral surface of the wound electrode group includes a flat portion and a curved portion.

[0003] During the use of the battery cell, the wound electrode group will expand. Due to the bending stress existing in the curved portion itself, under the combined action of the expansion force and the bending stress, the electrode sheet corresponding to the curved portion is more likely to be stressed and cracked. After the electrode sheet is cracked, the sharp edge of the electrode sheet pierces the separator, resulting in the short circuit of the positive electrode sheet and the negative electrode sheet, further triggering thermal runaway, and affecting the reliability and safety of the battery cell. Therefore, how to reduce the possibility of cracking of the curved portion of the wound electrode group is a technical problem to be solved. Summary of the Utility Model

[0004] In view of the above problems, the present application provides a battery cell, a battery device, and an electrical device, and the battery cell can reduce the possibility of cracking of the curved portion of the wound electrode group during use.

[0005] In a first aspect, the present application provides a battery cell, including: a housing; an electrode assembly, the electrode assembly is disposed inside the housing and includes at least one wound electrode group, the outer peripheral surface of the wound electrode group includes a flat portion and a curved portion, in the circumferential direction of the wound electrode group, the flat portion extends along a straight line, and the curved portion extends along a curve;

[0006] a support structure, the support structure is disposed inside the housing and is located between the outer peripheral side of the wound electrode group and the housing, at least a part of the support structure is located between the curved portion and the housing, the surface of the support structure facing the wound electrode group constitutes a constraint surface, and the constraint surface is in contact with or connected to the curved portion.

[0007] In the above technical solution, by providing a support structure inside the housing and at least a part of the support structure is located between the curved portion of the wound electrode group and the housing, the constraint on the expansion deformation of the curved portion can be increased, the possibility of cracking of the electrode sheet corresponding to the curved portion can be reduced, and further the possibility of short circuit of the battery cell caused by the cracking of the electrode sheet can be reduced or avoided, which is beneficial to improving the reliability and safety of the battery cell; and, by the constraint surface being in contact with or connected to the curved portion, the constraint surface can be made to fit the curved portion, so that the constraint on the expansion deformation of the curved portion by the support structure can be effectively increased, and further the possibility of cracking of the electrode sheet corresponding to the curved portion can be effectively reduced.

[0008] In some embodiments, the shape of the constraint surface is the same as that of the curved surface portion.

[0009] In the above technical solution, by making the shape of the constraint surface the same as that of the curved surface portion, the constraint surface can be closely attached to the curved surface portion. In this way, when the curved surface portion expands, the constraint surface with the same shape can disperse stress more evenly, avoiding local stress concentration on the curved surface portion, so that the constraint surface can play a role in evenly supporting and constraining the curved surface portion, effectively reducing the possibility of cracking of the curved surface portion caused by stress concentration.

[0010] In some embodiments, in the circumferential direction of the wound electrode group, both the constraint surface and the curved surface portion extend along an arc.

[0011] In the above technical solution, by making both the constraint surface and the curved surface portion extend along an arc, the constraint surface can be closely attached to the curved surface portion. In this way, the constraint surface can play a role in evenly supporting and constraining the curved surface portion, effectively reducing the possibility of cracking of the curved surface portion caused by stress concentration.

[0012] In some embodiments, the ratio range of the radius of curvature of the constraint surface to the radius of curvature of the curved surface portion is 0.9 to 1.1.

[0013] In the above technical solution, by the ratio range of the radius of curvature of the constraint surface to the radius of curvature of the curved surface portion being 0.9 to 1.1, a certain manufacturing error in the radius of curvature between the constraint surface and the curved surface portion can be allowed, making the manufacturing of the support structure more convenient, and the constraint surface can be made to fit the curved surface portion as much as possible, so as to effectively increase the support and constraint effect on the curved surface portion and reduce the possibility of cracking of the electrode sheet on the curved surface portion.

[0014] In some embodiments, the support structure is in contact with or connected to the housing.

[0015] In the above technical solution, by the support structure being in contact with or connected to the housing, the overall stability of the support structure and the housing can be enhanced, and the housing can play a role in supporting the support structure. Furthermore, the support and constraint effect of the support structure on the curved surface portion can be enhanced, further reducing the possibility of cracking of the electrode sheet on the curved surface portion.

[0016] In some embodiments, the surface of the inner wall of the housing facing the support structure is the first side wall surface, and the surface of the support structure facing the inner wall of the housing is the second side wall surface, and both the first side wall surface and the second side wall surface are flat surfaces.

[0017] In the above technical solution, the surface of the inner wall of the housing facing the support structure is the first side wall surface, and the surface of the support structure facing the inner wall of the housing is the second side wall surface. Both the first side wall surface and the second side wall surface are flat surfaces. The flat first side wall surface contacts the flat second side wall surface, which can make the support structure fit closely with the housing. In this way, the contact area between the support structure and the housing can be relatively large, thereby enhancing the support effect between the housing and the support structure.

[0018] In some embodiments, the wound electrode group includes an electrode group main body and electrode tabs. The electrode tabs are connected to the axial side of the electrode group main body. The ratio range of the height dimension of the support structure in the axial direction of the wound electrode group to the height dimension of the electrode group main body in the axial direction of the wound electrode group is 0.7 to 1.0.

[0019] In the above technical solution, by setting the ratio range of the height dimension of the support structure in the axial direction of the wound electrode group to the height dimension of the electrode group main body in the axial direction of the wound electrode group to be 0.7 to 1.0, the height of the support structure in the axial direction can be relatively large. In this way, the contact area between the support structure and the electrode group main body can be relatively large, so that the support structure has a strong constraining effect on the electrode group main body, thereby effectively reducing the possibility of cracking of the electrode group main body; and, it can make the overall structure of the support structure and the wound electrode group compact.

[0020] In some embodiments, the wound electrode group includes an electrode group main body and electrode tabs. The electrode tabs are connected to the axial side of the electrode group main body. The electrode group main body has opposite first end face and second end face in the axial direction of the wound electrode group. The support structure has opposite third end face and fourth end face in the axial direction of the wound electrode group. The first end face and the third end face are located on the same side in the axial direction of the wound electrode group. The third end face is flush with the first end face or the plane where the third end face is located is on the side close to the second end face of the plane where the first end face is located. The second end face and the fourth end face are located on the same side in the axial direction of the wound electrode group. The fourth end face is flush with the second end face or the plane where the fourth end face is located is on the side close to the first end face of the plane where the second end face is located.

[0021] In the above technical scheme, by setting the third end face of the support structure flush with the first end face of the pole group body or the plane where the third end face is located is located on the side of the plane where the first end face is located close to the second end face, the structure of the support structure and the pole group body as a whole can be made compact, and the additional external space occupied by the third end face of the support structure protruding from the first end face along the side away from the second end face can be reduced; and, by setting the fourth end face of the support structure flush with the second end face or the plane where the fourth end face is located is located on the side of the plane where the second end face is located close to the first end face, the structure of the support structure and the pole group body as a whole can be made compact, and the additional external space occupied by the fourth end face of the support structure protruding from the second end face along the side away from the first end face can be reduced.

[0022] In some embodiments, the support structure is an insulating structure or the surface structure of the support structure is an insulating structure.

[0023] In the above technical solution, by using the supporting structure as an insulating structure or the surface structure of the supporting structure as an insulating structure, it is possible to avoid electrical connection between the supporting structure and the wound electrode group, thereby improving the overall electrical safety of the battery cell.

[0024] In some embodiments, the support structure is a plastic structure or an insulating glue structure.

[0025] In the above technical solution, the support structure is a plastic structure or an insulating rubber structure, so that the support structure can be an insulating structure to effectively avoid electrical connection between the support structure and the wound electrode group, which is beneficial to improving the overall electrical safety of the battery cell.

[0026] In some embodiments, a cavity is defined within the support structure.

[0027] In the above technical solution, by providing a cavity in the support structure, the weight of the support structure can be reduced, thereby reducing the overall weight of the battery cell, which is beneficial to the lightweight of the battery cell.

[0028] In some embodiments, the cavity extends along the axial direction of the wound pole group.

[0029] In the above technical solution, the weight of the support structure can be effectively reduced by extending the cavity along the axial direction of the wound electrode group, thereby effectively reducing the weight of the battery cell as a whole; and, in this way, the support structure has a solid part at each position in the axial direction to support the wound electrode group, which can reduce the possibility of reducing the overall structural strength of the support structure due to the cavity.

[0030] In some embodiments, the support structure is further provided with a connecting hole connecting the cavity with the inner cavity of the shell, and at least a portion of the cavity is used to store electrolyte.

[0031] In the above technical solution, a communication hole communicating the cavity with the inner cavity of the housing is further provided on the support structure, and at least a part of the cavity is used to store the electrolyte. The communication hole can communicate the cavity with the inner cavity of the housing, so that the electrolyte stored in the cavity can diffuse into the inner cavity of the housing through the communication hole, facilitating the full contact between the wound electrode group in the inner cavity and the electrolyte, which is beneficial to improving the overall performance of the battery cell.

[0032] In some embodiments, the support structure has opposite third end faces and fourth end faces in the axial direction of the wound electrode group, and the cavity axially penetrates through the third end face and / or the fourth end face along the axial direction of the wound electrode group to form the communication hole.

[0033] In the above technical solution, since the support structure has opposite third end faces and fourth end faces in the axial direction of the wound electrode group, and the cavity axially penetrates through the third end face and / or the fourth end face along the axial direction of the wound electrode group, the cavity forms a communication hole at one or both ends in the axial direction of the wound electrode group, facilitating the electrolyte in the cavity to flow into the inner cavity of the housing through the communication hole at one or both ends of the cavity in the axial direction of the wound electrode group, and further facilitating the full contact between the wound electrode group in the inner cavity and the electrolyte.

[0034] In some embodiments, the outer peripheral surface of the wound electrode group includes two flat portions and two curved portions. The two flat portions are opposite and spaced apart in a first direction, and the two curved portions are opposite and spaced apart in a second direction. The first direction, the second direction, and the axial direction of the wound electrode group intersect pairwise. The support structure includes a plurality of support members, and at least one support member is provided between each curved portion and the housing.

[0035] In the above technical solution, since the support structure includes a plurality of support members and at least one support member is provided between each curved portion and the housing, each curved portion of the wound electrode group can be effectively supported and constrained by the support members, which can effectively reduce the possibility of cracking of each curved portion of the wound electrode group, thereby improving the overall reliability of the battery cell.

[0036] In some embodiments, a cavity is provided in the support member, and the cavity extends in the axial direction of the wound electrode group. The ratio of the total cross-sectional area of all the cavities of a single support member to the cross-sectional area of the single support member ranges from 0.4 to 0.6.

[0037] In the above technical solution, the ratio range of the total cross-sectional area of all cavities of a single support member to the cross-sectional area of the single support member is 0.4 to 0.6, which can make the total cross-sectional area of all cavities of the single support member larger, so that more electrolyte can be stored in the cavities, facilitating sufficient contact between the wound electrode group in the inner cavity of the housing and the electrolyte; and can make the support member have stronger structural strength to effectively support and restrain the wound electrode group.

[0038] In some embodiments, a plurality of cavities are provided in the support member, each cavity extends along the axial direction of the wound electrode group, and the plurality of cavities of the single support member are arranged at intervals along the circumferential direction of the wound electrode group.

[0039] In the above technical solution, by providing a plurality of cavities in the support member and each cavity extending along the axial direction of the wound electrode group, for example, at least part of the cavity is used to store electrolyte, and communication holes are formed at one or both ends of the cavity along the axial direction of the wound electrode group, the electrolyte in the cavity can diffuse more smoothly to the inner cavity of the housing through the communication holes at one or both ends along the axial direction of the wound electrode group, facilitating contact between the wound electrode group and the electrolyte; and by arranging the plurality of cavities of the single support member at intervals along the circumferential direction of the wound electrode group, the electrolyte in the cavity can diffuse more evenly to the wound electrode group, enabling each part of the wound electrode group to be in more sufficient contact with the electrolyte, which is beneficial to improving the overall performance of the battery cell.

[0040] In some embodiments, two support members are provided between each curved surface portion and the housing, and the two support members corresponding to each curved surface portion are arranged at intervals along the first direction.

[0041] In the above technical solution, by providing two support members between each curved surface portion and the housing, and the two support members corresponding to each curved surface portion are arranged at intervals along the first direction, the contact area between the support structure and each curved surface portion can be increased, thereby effectively increasing the restraint on the expansion deformation of each curved surface portion and effectively reducing the possibility of cracking of the curved surface portion.

[0042] In some embodiments, there are a plurality of wound electrode groups, the plurality of wound electrode groups are arranged along the first direction, and the support members adjacent in the first direction and located on the same side in the second direction of two adjacent wound electrode groups are connected.

[0043] In the above technical solution, by connecting the supporting members of two adjacent wound pole groups that are on the same side in the second direction and adjacent in the first direction, a continuous and stable supporting structure can be formed to effectively support and restrain the curved surfaces of the two adjacent wound pole groups. Moreover, the connection of adjacent supporting members can limit the adjacent wound pole groups, reducing or avoiding the possibility of the adjacent wound pole groups moving along the first direction.

[0044] In some embodiments, the supporting members of two adjacent wound pole groups that are on the same side in the second direction and adjacent in the first direction are integrally formed.

[0045] In the above technical solution, by integrally forming the supporting members of two adjacent wound pole groups that are on the same side in the second direction and adjacent in the first direction, to a certain extent, the overall structural strength of the adjacent supporting members of the two adjacent wound pole groups on the same side in the second direction and adjacent in the first direction can be enhanced, and the assembly process of the adjacent supporting members between the two adjacent wound pole groups can also be omitted, thereby improving the overall assembly efficiency of the battery device.

[0046] In a second aspect, the present application provides a battery device, including: a box body; a battery cell according to the first aspect embodiment of the present application, and the battery cell is disposed in the box body.

[0047] In the above technical solution, by providing the above battery cell, the battery device can have high reliability and good performance.

[0048] In a third aspect, the present application provides an electrical device, including the battery device according to the second aspect embodiment of the present application.

[0049] In the above technical solution, by providing the above battery device, the electrical device can have high reliability and good performance.

[0050] The additional aspects and advantages of the present application will be partially given in the following description, partially become apparent from the following description, or be understood through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] The above and / or additional aspects and advantages of the present application will become apparent and be easily understood from the description of the embodiments in conjunction with the following drawings, where:

[0052] Figure 1 is an exploded view of a battery cell according to some embodiments of the present application;

[0053] Figure 2 is Figure 1 a perspective schematic diagram of a partial structure of the battery cell in

[0054] Figure 3 is Figure 1 The assembly schematic diagram of the wound electrode group and the support structure in the battery cell in

[0055] Figure 4 is Figure 3 The separation schematic diagram of the wound electrode group and the support structure in the battery cell in

[0056] Figure 5 is Figure 4 The three-dimensional schematic diagram of the wound electrode group in

[0057] Figure 6 is Figure 4 The three-dimensional schematic diagram of the support structure in

[0058] Figure 7 is the simplified schematic diagram of the battery device according to some embodiments of the present application;

[0059] Figure 8 is the simplified schematic diagram of the electrical device according to some embodiments of the present application.

[0060] Reference numerals:

[0061] 1000, electrical device;

[0062] 100, battery device;

[0063] 10, battery cell;

[0064] 11, housing; 111, first side wall surface;

[0065] 12, electrode assembly; 121, wound electrode group; 1211, planar part; 1212, curved part; 1213, electrode group main body; 1214, tab; 1215, first end face;

[0066] 13, support structure; 131, constraint surface; 132, second side wall surface; 133, third end face; 135, cavity; 1351, communication hole; 136, support member;

[0067] 141, explosion-proof valve; 142, positive electrode post; 143, negative electrode post; 144, top cover; 145, lower plastic; 146, adapter plate;

[0068] 200, vehicle body. Detailed implementation manners

[0069] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of them. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

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

[0071] Referring to "embodiments" in this application means that specific features, structures, or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0072] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled", and "attached" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0073] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that three relationships can 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 represents an "or" relationship between the associated objects before and after.

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

[0075] In this application, "a plurality of" means two or more.

[0076] In the embodiments of this application, if there is no special description, all embodiments and optional embodiments of this application can be combined with each other to form a new technical solution.

[0077] In the embodiments of this application, if there is no special description, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0078] In the embodiments of this application, the battery device may include one or more battery cell assemblies for providing voltage and capacity. The battery cell assembly may include a plurality of battery cells, and the plurality of battery cells are connected in series, parallel or in a hybrid connection through a busbar component. For example, the battery cell assembly is usually formed by arranging a plurality of battery cells; the battery cell assembly may be a battery module, and the battery module is formed by arranging and fixing a plurality of battery cells to form an independent module. As an example, the battery module can be formed by bundling a plurality of battery cells with cable ties.

[0079] The battery device may be a battery pack, and the battery pack includes a box body and one or more battery cell assemblies, and the battery cell assemblies are accommodated in the box body. The battery cell assembly may be a battery module, and the battery cell assembly may be accommodated in the box body by fixing the battery module in the box body; the battery cell assembly may also be accommodated in the box body by directly fixing a plurality of battery cells to the box body.

[0080] In the embodiments of this application, the box body may include a first box body and a second box body. The first box body and the second box body are buckled so that a closed space is formed inside the box body to accommodate the battery cell assembly. Here, "closed" means covered or closed, which can be sealed or non-sealed. The first box body may be a top cover or a bottom plate. For example, the box body may include a top cover, a frame and a bottom plate. The top cover and the bottom plate are respectively connected to the frame so that a closed space is formed inside the box body to accommodate the battery cell assembly.

[0081] In the embodiments of this application, the box body can be part of the chassis structure of a vehicle. For example, part of the box body can become at least part of the floor of the vehicle, or part of the box body can become at least part of the cross beam and longitudinal beam of the vehicle.

[0082] In the embodiments of the present application, the battery cell may be a secondary battery, which refers to a battery cell that can be activated by charging after discharging so that the active material can be reused; the battery cell may be a lithium-ion battery, a sodium-ion battery, a sodium-lithium-ion battery, a lithium metal battery, a sodium metal battery, a lithium-sulfur battery, a magnesium-ion battery, a nickel-metal hydride battery, a nickel-cadmium battery, a lead-acid battery, etc., and the embodiments of the present application do not limit this. The battery cell may be in the shape of a cylinder, a flat body, a cuboid or other shapes, and the embodiments of the present application do not limit this either. Generally, the battery cells are divided into three types according to the packaging method: cylindrical battery cells, square battery cells and soft-pack battery cells, and the embodiments of the present application do not limit this either.

[0083] At present, from the perspective of the development of the market situation, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage power systems such as hydroelectric, thermal, wind and solar power stations, but also widely used in electric vehicles such as electric bicycles, electric motorcycles and electric cars, as well as in many fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also increasing continuously.

[0084] In the related art, the battery cell includes a housing and an electrode assembly disposed in the housing. The electrode assembly includes at least one wound electrode group, and the wound electrode group is formed by laminating and winding a positive electrode sheet, a negative electrode sheet and a separator. The outer peripheral surface of the wound electrode group includes a flat portion and a curved portion. During the use of the battery cell, the wound electrode group will expand. Due to the bending stress existing in the curved portion itself, under the combined action of the expansion force and the bending stress, the electrode sheet corresponding to the curved portion is more likely to be stressed and cracked. After the electrode sheet is cracked, the sharp edge of the electrode sheet pierces the separator, resulting in the short circuit of the positive electrode sheet and the negative electrode sheet, further triggering thermal runaway and affecting the reliability and safety of the battery cell.

[0085] Based on this, the present application proposes a battery cell, which includes a housing, an electrode assembly and a support structure. The electrode assembly is disposed in the housing and includes at least one wound electrode group. The outer peripheral surface of the wound electrode group includes a flat portion and a curved portion. In the circumferential direction of the wound electrode group, the flat portion extends along a straight line, and the curved portion extends along a curve. The support structure is disposed in the housing and is located between the outer peripheral side of the wound electrode group and the housing. At least a part of the support structure is located between the curved portion and the housing. The surface of the support structure facing the wound electrode group constitutes a constraint surface, and the constraint surface is in contact with or connected to the curved portion.

[0086] In the above-mentioned battery cell, by arranging a support structure inside the housing and at least part of the support structure being located between the curved surface part of the wound electrode assembly and the housing, the expansion deformation constraint on the curved surface part can be increased, the possibility of cracking of the electrode corresponding to the curved surface part can be reduced, and further the possibility of short circuit of the battery cell caused by electrode cracking can be reduced or avoided, which is beneficial to improving the reliability and safety of the battery cell; moreover, by the contact or connection between the constraint surface and the curved surface part, the constraint surface can be fitted to the curved surface part, so that the expansion deformation constraint of the support structure on the curved surface part can be effectively increased, and further the possibility of cracking of the electrode corresponding to the curved surface part can be effectively reduced.

[0087] The battery device disclosed in the embodiments of the present application can be used in electrical equipment using the battery device as a power source or various energy storage systems using the battery device as an energy storage element. In addition to being used in vehicles, the battery device can also be used in, but not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, battery cars, electric vehicles, ships, spacecraft, and so on. Among them, the electric toys can include fixed or mobile electric toys, such as game consoles, electric vehicle toys, electric ship toys, and electric aircraft toys, etc., and the spacecraft can include airplanes, rockets, space shuttles, and spaceships, etc.

[0088] The electrical device disclosed in the embodiments of the present application can be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or an extended-range electric vehicle, etc. The battery device is arranged inside the vehicle, and the battery device can be arranged at the bottom, head, or tail of the vehicle. The battery device can be used for power supply of the vehicle. For example, the battery device can be used as the operating power source of the vehicle. The vehicle can also include a controller and a motor, and the controller is used to control the battery device to supply power to the motor. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle. In some embodiments of the present application, the battery device can not only be used as the operating power source of the vehicle, but also be used as the driving power source of the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0089] Next, refer to Figures 1-6 Describe the battery cell 10 according to the embodiments of the present application.

[0090] Refer to Figures 1-3, in a first aspect, the present application provides a battery cell 10, comprising a housing 11, an electrode assembly 12 and a support structure 13. The electrode assembly 12 is disposed within the housing 11 and the electrode assembly 12 includes at least one wound electrode group 121. The outer peripheral surface of the wound electrode group 121 includes a flat portion 1211 and a curved portion 1212. In the circumferential direction of the wound electrode group 121, the flat portion 1211 extends along a straight line and the curved portion 1212 extends along a curve. The support structure 13 is disposed within the housing 11 and the support structure 13 is located between the outer peripheral side of the wound electrode group 121 and the housing 11. At least a part of the support structure 13 is located between the curved portion 1212 and the housing 11. The surface of the support structure 13 facing the wound electrode group 121 constitutes a constraint surface 131, and the constraint surface 131 is in contact with or connected to the curved portion 1212.

[0091] Wherein, at least a part of the support structure 13 being located between the curved portion 1212 and the housing 11 may include the following situations: for example, a part of the support structure 13 may be located between the curved portion 1212 and the housing 11; for another example, the entire support structure 13 may also be located between the curved portion 1212 and the housing 11.

[0092] The wound electrode group 121 includes a positive electrode sheet, a negative electrode sheet and a separator. The wound electrode group 121 is formed by winding the positive electrode sheet, the negative electrode sheet and the separator after lamination. The separator is disposed between the positive electrode sheet and the negative electrode sheet. The separator being located between the positive electrode sheet and the negative electrode sheet can play a role of isolation to prevent the positive electrode sheet and the negative electrode sheet from directly contacting and short-circuiting. The housing 11 can play a certain role in supporting and protecting the wound electrode group 121, reducing or avoiding damage to the wound electrode group 121 due to external impact.

[0093] By the support structure 13 being located between the outer peripheral side of the wound electrode group 121 and the housing 11, this part of the space between the wound electrode group 121 and the housing 11 can be fully utilized, making the overall structure of the support structure 13, the wound electrode group 121 and the housing 11 compact; and, by at least a part of the support structure 13 being located between the curved portion 1212 and the housing 11, this part of the space between the curved portion 1212 and the housing 11 can be filled to play a role in supporting the curved portion 1212. In this way, the constraint on the expansion deformation of the curved portion 1212 can be increased, reducing the possibility of the curved portion 1212 deforming due to the expansion force, and further reducing the possibility of the curved portion 1212 cracking, which is beneficial to improving the overall reliability of the battery cell 10.

[0094] For example, during the use of the battery cell 10, the wound electrode group 121 will expand. In particular, due to the bending stress existing in the curved surface portion 1212 itself, under the combined action of the expansion force and the bending stress, the electrode sheet corresponding to the curved surface portion 1212 is more likely to be stressed and cracked. After the electrode sheet is cracked, the sharp edge of the electrode sheet pierces the separator, resulting in the lap joint and short circuit of the positive electrode sheet and the negative electrode sheet, further triggering thermal runaway. By having at least a part of the support structure 13 located between the curved surface portion 1212 and the housing 11, this part of the space between the curved surface portion 1212 and the housing 11 can be filled to support and restrain the curved surface portion 1212. In this way, the expansion deformation restraint of the curved surface portion 1212 can be increased, thereby reducing the possibility of cracking of the electrode sheet corresponding to the curved surface portion 1212, and the problem that the electrode sheet pierces the separator due to the cracking of the electrode sheet corresponding to the curved surface portion 1212, and then leads to the lap joint and short circuit of the positive electrode sheet and the negative electrode sheet can be reduced or avoided. Correspondingly, the risk of thermal runaway can be reduced.

[0095] By making the constraint surface 131 contact or connect with the curved surface portion 1212, the constraint surface 131 can be made to fit the curved surface portion 1212. In this way, the expansion deformation restraint of the support structure 13 on the curved surface portion 1212 can be effectively increased, and the possibility of cracking of the electrode sheet corresponding to the curved surface portion 1212 can be reduced.

[0096] In addition, by having at least a part of the support structure 13 located between the curved surface portion 1212 and the housing 11, the free expansion deformation amount of the curved surface portion 1212 can be reduced, and thus the lithium plating due to the excessive distance between the electrode sheets corresponding to the curved surface portion 1212 can be prevented, which is beneficial to improving the cycle life of the battery cell 10.

[0097] For example, the battery cell 10 further includes an explosion-proof valve 141, a positive electrode terminal 142, a negative electrode terminal 143, a top cover 144, a lower plastic 145, and a connecting piece 146. The explosion-proof valve 141, the positive electrode terminal 142, the negative electrode terminal 143, the top cover 144, the lower plastic 145, and the connecting piece 146 are sequentially arranged along the axial direction of the wound electrode group 121 and are provided at one end in the axial direction of the wound electrode group 121.

[0098] In the above technical solution, by providing the support structure 13 in the housing 11 and having at least a part of the support structure 13 located between the curved surface portion 1212 of the wound electrode group 121 and the housing 11, the expansion deformation restraint of the curved surface portion 1212 can be increased, the possibility of cracking of the electrode sheet corresponding to the curved surface portion 1212 can be reduced, and further the possibility of short circuit of the battery cell 10 caused by the cracking of the electrode sheet can be reduced or avoided, which is beneficial to improving the reliability and safety of the battery cell 10; and, by making the constraint surface 131 contact or connect with the curved surface portion 1212, the constraint surface 131 can be made to fit the curved surface portion 1212. In this way, the expansion deformation restraint of the support structure 13 on the curved surface portion 1212 can be effectively increased, and further the possibility of cracking of the electrode sheet corresponding to the curved surface portion 1212 can be effectively reduced.

[0099] Reference Figures 1-4 , in some embodiments, the shape of the constraint surface 131 is the same as that of the curved surface portion 1212.

[0100] By making the shape of the constraint surface 131 the same as that of the curved surface portion 1212, the constraint surface 131 can be more closely attached to the curved surface portion 1212. In this way, when the curved surface portion 1212 expands, the constraint surface 131 with the same shape can more evenly disperse the stress of the curved surface portion 1212, avoiding local stress concentration on the curved surface portion 1212, so that the constraint surface 131 can play a role of evenly supporting and constraining the curved surface portion 1212, effectively reducing the possibility of cracking of the curved surface portion 1212 caused by stress concentration.

[0101] In the above technical solution, by making the shape of the constraint surface 131 the same as that of the curved surface portion 1212, the constraint surface 131 can be more closely attached to the curved surface portion 1212. In this way, when the curved surface portion 1212 expands, the constraint surface 131 with the same shape can more evenly disperse the stress, avoiding local stress concentration on the curved surface portion 1212, so that the constraint surface 131 can play a role of evenly supporting and constraining the curved surface portion 1212, effectively reducing the possibility of cracking of the curved surface portion 1212 caused by stress concentration.

[0102] Reference Figures 1-4 , in some embodiments, in the circumferential direction of the wound electrode group 121, both the constraint surface 131 and the curved surface portion 1212 extend along an arc.

[0103] The wound electrode group 121 is formed by winding a positive electrode sheet, a negative electrode sheet, and a separator layer. The separator is disposed between the positive electrode sheet and the negative electrode sheet to prevent the positive electrode sheet and the negative electrode sheet from directly contacting and short-circuiting. Thus, the curved surface portion 1212 extends along an arc. By making the constraint surface 131 extend along an arc, the constraint surface 131 can be more closely attached to the curved surface portion 1212. In this way, the constraint surface 131 can play a role of evenly supporting and constraining the curved surface portion 1212, effectively reducing the possibility of cracking of the curved surface portion 1212 caused by stress concentration.

[0104] In the above technical solution, by making both the constraint surface 131 and the curved surface portion 1212 extend along an arc, the constraint surface 131 can be more closely attached to the curved surface portion 1212. In this way, the constraint surface 131 can play a role of evenly supporting and constraining the curved surface portion 1212, effectively reducing the possibility of cracking of the curved surface portion 1212 caused by stress concentration.

[0105] Reference Figures 1-4 , in some embodiments, the ratio range of the radius of curvature of the constraint surface 131 to the radius of curvature of the curved surface portion 1212 is 0.9 to 1.1.

[0106] For example, the ratio of the radius of curvature of the constraint surface 131 to the radius of curvature of the curved surface portion 1212 can be 0.9, 0.95, 1, 1.05, 1.1, etc. By setting the ratio range of the radius of curvature of the constraint surface 131 to the radius of curvature of the curved surface portion 1212 to be 0.9 - 1.1, certain manufacturing errors in the radii of curvature of the constraint surface 131 and the curved surface portion 1212 can be allowed, making the manufacturing of the support structure 13 more convenient. Moreover, the constraint surface 131 can be made to fit the curved surface portion 1212 as closely as possible, effectively increasing the support and constraint effects on the curved surface portion 1212 and reducing the possibility of the pole piece cracking on the curved surface portion 1212.

[0107] In the above technical solution, by setting the ratio range of the radius of curvature of the constraint surface 131 to the radius of curvature of the curved surface portion 1212 to be 0.9 - 1.1, certain manufacturing errors in the radii of curvature of the constraint surface 131 and the curved surface portion 1212 can be allowed, making the manufacturing of the support structure 13 more convenient. Moreover, the constraint surface 131 can be made to fit the curved surface portion 1212 as closely as possible, effectively increasing the support and constraint effects on the curved surface portion 1212 and reducing the possibility of the pole piece cracking on the curved surface portion 1212.

[0108] Reference Figures 1-3 , in some embodiments, the support structure 13 is in contact with or connected to the housing 11.

[0109] By the support structure 13 being in contact with or connected to the housing 11, the overall stability of the support structure 13 and the housing 11 can be enhanced, and the housing 11 can support the support structure 13. Furthermore, the support and constraint effects of the support structure 13 on the curved surface portion 1212 can be strengthened, further reducing the possibility of the pole piece cracking on the curved surface portion 1212.

[0110] In the above technical solution, by the support structure 13 being in contact with or connected to the housing 11, the overall stability of the support structure 13 and the housing 11 can be enhanced, and the housing 11 can support the support structure 13. Furthermore, the support and constraint effects of the support structure 13 on the curved surface portion 1212 can be strengthened, further reducing the possibility of the pole piece cracking on the curved surface portion 1212.

[0111] Reference Figures 1-3 , in some embodiments, the surface of the inner wall of the housing 11 facing the support structure 13 is the first side wall surface 111, and the surface of the support structure 13 facing the inner wall of the housing 11 is the second side wall surface 132, and both the first side wall surface 111 and the second side wall surface 132 are flat surfaces.

[0112] The surface of the inner wall of the housing 11 facing the support structure 13 is the first side wall surface 111, and the surface of the support structure 13 facing the inner wall of the housing 11 is the second side wall surface 132. Both the first side wall surface 111 and the second side wall surface 132 are flat surfaces. The flat first side wall surface 111 contacts the flat second side wall surface 132, which can make the support structure 13 fit closely with the housing 11. In this way, the contact area between the support structure 13 and the housing 11 can be relatively large, thereby enhancing the support effect between the housing 11 and the support structure 13.

[0113] In the above technical solution, the surface of the inner wall of the housing 11 facing the support structure 13 is the first side wall surface 111, and the surface of the support structure 13 facing the inner wall of the housing 11 is the second side wall surface 132. Both the first side wall surface 111 and the second side wall surface 132 are flat surfaces. The flat first side wall surface 111 contacts the flat second side wall surface 132, which can make the support structure 13 fit closely with the housing 11. In this way, the contact area between the support structure 13 and the housing 11 can be relatively large, thereby enhancing the support effect between the housing 11 and the support structure 13.

[0114] Reference Figures 1-3 , in some embodiments, the wound electrode group 121 includes an electrode group main body 1213 and an electrode tab 1214. The electrode tab 1214 is connected to the axial side of the electrode group main body 1213. The ratio range of the height dimension h1 of the support structure 13 in the axial direction of the wound electrode group 121 to the height dimension h2 of the electrode group main body 1213 in the axial direction of the wound electrode group 121 is 0.7 to 1.0.

[0115] For example, the ratio of the height dimension h1 of the support structure 13 in the axial direction of the wound electrode group 121 to the height dimension h2 of the electrode group main body 1213 in the axial direction of the wound electrode group 121 can be 0.7, 0.8, 0.9, 1.0, etc. By making the ratio of the height dimension h1 of the support structure 13 in the axial direction of the wound electrode group 121 to the height dimension h2 of the electrode group main body 1213 in the axial direction of the wound electrode group 121 not less than 0.7, the height of the support structure 13 in the axial direction can be relatively large. In this way, the contact area between the support structure 13 and the electrode group main body 1213 can be relatively large, so that the support structure 13 has a strong constraint effect on the electrode group main body 1213, thereby effectively reducing the possibility of cracking of the electrode group main body 1213; by making the ratio of the height dimension h1 of the support structure 13 in the axial direction of the wound electrode group 121 to the height dimension h2 of the electrode group main body 1213 in the axial direction of the wound electrode group 121 not greater than 1.0, the overall structure of the support structure 13 and the wound electrode group 121 can be made compact, reducing the occupation of additional external space due to one end of the support structure 13 protruding from the surface of the wound electrode group 121 along the axial direction of the wound electrode group 121.

[0116] In the above technical solution, by making the ratio of the height dimension h1 of the support structure 13 in the axial direction of the wound pole group 121 to the height dimension h2 of the pole group body 1213 in the axial direction of the wound pole group 121 in the range of 0.7~1.0, the height of the support structure 13 in the axial direction can be made larger, so that the contact area between the support structure 13 and the pole group body 1213 can be made larger, so that the support structure 13 has a stronger restraining effect on the pole group body 1213, thereby effectively reducing the possibility of cracking of the pole group body 1213; and the overall structure of the support structure 13 and the wound pole group 121 can be made compact.

[0117] refer to Figures 4-6 In some embodiments, the wound pole group 121 includes a pole group body 1213 and a pole ear 1214, the pole ear 1214 is connected to the axial side of the pole group body 1213, the pole group body 1213 has a first end face 1215 and a second end face relative to each other in the axial direction of the wound pole group 121, the support structure 13 has a third end face 133 and a fourth end face relative to each other in the axial direction of the wound pole group 121, the first end face 1215 and the third end face 133 are located on the same side of the axial direction of the wound pole group 121, the third end face 133 is flush with the first end face 1215 or the plane where the third end face 133 is located is located on the side of the plane where the first end face 1215 is located close to the second end face, the second end face and the fourth end face are located on the same side of the axial direction of the wound pole group 121, the fourth end face is flush with the second end face or the plane where the fourth end face is located is located on the side of the plane where the second end face is located close to the first end face 1215.

[0118] While the support structure 13 effectively constrains the curved surface portion 1212 of the wound pole group 121, the third end face 133 of the support structure 13 is flush with the first end face 1215 of the pole group body 1213 or the plane where the third end face 133 is located is located on the side of the plane where the first end face 1215 is located close to the second end face, so that the overall structure of the support structure 13 and the pole group body 1213 can be made compact, which can reduce the additional external space occupied by the third end face 133 of the support structure 13 protruding from the first end face 1215 along the side away from the second end face; and, the fourth end face of the support structure 13 is flush with the second end face or the plane where the fourth end face is located is located on the side of the plane where the second end face is located close to the first end face 1215, so that the overall structure of the support structure 13 and the pole group body 1213 can be made compact, which can reduce the additional external space occupied by the fourth end face of the support structure 13 protruding from the second end face along the side away from the first end face 1215.

[0119] In the above technical scheme, by setting the third end face 133 of the support structure 13 flush with the first end face 1215 of the pole group body 1213 or the plane where the third end face 133 is located is located on the side of the plane where the first end face 1215 is located close to the second end face, the overall structure of the support structure 13 and the pole group body 1213 can be made compact, and the additional external space occupied by the third end face 133 of the support structure 13 protruding from the first end face 1215 along the side away from the second end face can be reduced; and, by setting the fourth end face of the support structure 13 flush with the second end face or the plane where the fourth end face is located is located on the side of the plane where the second end face is located close to the first end face 1215, the overall structure of the support structure 13 and the pole group body 1213 can be made compact, and the additional external space occupied by the fourth end face of the support structure 13 protruding from the second end face along the side away from the first end face 1215 can be reduced.

[0120] refer to Figures 4-6 In some embodiments, the support structure 13 is an insulating structure or the surface structure of the support structure 13 is an insulating structure.

[0121] By using the support structure 13 as an insulating structure or the surface structure of the support structure 13 as an insulating structure, electrical connection between the support structure 13 and the wound electrode group 121 can be avoided, which is beneficial to improving the overall electrical safety of the battery cell 10 .

[0122] In the above technical solution, by making the support structure 13 an insulating structure or the surface structure of the support structure 13 an insulating structure, the support structure 13 can be prevented from being electrically connected to the wound electrode group 121 , thereby improving the overall electrical safety of the battery cell 10 .

[0123] refer to Figure 6 In some embodiments, the support structure 13 is a plastic structure or an insulating glue structure.

[0124] By making the support structure 13 into a plastic structure or an insulating rubber structure, the support structure 13 can be an insulating structure, so as to effectively avoid electrical connection between the support structure 13 and the wound electrode group 121 , which is beneficial to improving the overall electrical safety of the battery cell 10 .

[0125] For example, the insulating glue structure can be formed by expanding glue, and the expanding glue forms an insulating glue framework after curing. Since the expanding glue before curing has good fluidity, it can better fill the gap between the wound pole group 121 and the shell 11. In this way, the expanded glue after curing can better support and restrain the wound pole group 121.

[0126] In the above technical solution, since the support structure 13 is a plastic structure or an insulating glue structure, the support structure 13 can be an insulating structure, effectively avoiding electrical connection between the support structure 13 and the wound electrode group 121, which is beneficial to improving the overall electrical safety of the battery cell 10.

[0127] Reference Figure 6 , in some embodiments, a cavity 135 is provided in the support structure 13.

[0128] By providing the cavity 135 in the support structure 13, the weight of the support structure 13 can be reduced, thereby reducing the overall weight of the battery cell 10, which is beneficial to the lightweight of the battery cell 10.

[0129] In the above technical solution, by providing the cavity 135 in the support structure 13, the weight of the support structure 13 can be reduced, thereby reducing the overall weight of the battery cell 10, which is beneficial to the lightweight of the battery cell 10.

[0130] Reference Figure 5 And Figure 6 , in some embodiments, the cavity 135 extends along the axial direction of the wound electrode group 121.

[0131] By the cavity 135 extending along the axial direction of the wound electrode group 121, the weight of the support structure 13 can be effectively reduced, and thus the overall weight of the battery cell 10 can be effectively reduced; moreover, in this way, each part of the support structure 13 in the axial direction has a solid part to support the wound electrode group 121, which can reduce the possibility of reducing the overall structural strength of the support structure 13 due to the cavity 135.

[0132] In the above technical solution, by the cavity 135 extending along the axial direction of the wound electrode group 121, the weight of the support structure 13 can be effectively reduced, and thus the overall weight of the battery cell 10 can be effectively reduced; moreover, in this way, each part of the support structure 13 in the axial direction has a solid part to support the wound electrode group 121, which can reduce the possibility of reducing the overall structural strength of the support structure 13 due to the cavity 135.

[0133] Reference Figures 4-6 , in some embodiments, a communication hole 1351 communicating the cavity 135 with the inner cavity of the housing 11 is further provided on the support structure 13, and at least part of the cavity 135 is used for storing electrolyte.

[0134] Among them, at least part of the cavity 135 being used for storing electrolyte may include the following situations: for example, part of the cavity 135 may be used for storing electrolyte; or, for another example, the entire cavity 135 may be used for storing electrolyte.

[0135] A communication hole 1351 that connects the cavity 135 to the inner cavity of the housing 11 is further provided on the support structure 13, and at least a part of the cavity 135 is used to store the electrolyte. The communication hole 1351 can connect the cavity 135 to the inner cavity of the housing 11, so that the electrolyte stored in the cavity 135 can diffuse into the inner cavity of the housing 11 through the communication hole 1351, facilitating the wound electrode group 121 in the inner cavity to fully contact the electrolyte, which is beneficial to improving the overall performance of the battery cell 10.

[0136] In the above technical solution, a communication hole 1351 that connects the cavity 135 to the inner cavity of the housing 11 is further provided on the support structure 13, and at least a part of the cavity 135 is used to store the electrolyte. The communication hole 1351 can connect the cavity 135 to the inner cavity of the housing 11, so that the electrolyte stored in the cavity 135 can diffuse into the inner cavity of the housing 11 through the communication hole 1351, facilitating the wound electrode group 121 in the inner cavity to fully contact the electrolyte, which is beneficial to improving the overall performance of the battery cell 10.

[0137] Reference Figures 4-6 , in some embodiments, the support structure 13 has opposite third end faces 133 and fourth end faces in the axial direction of the wound electrode group 121, and the cavity 135 axially penetrates through the third end face 133 and / or the fourth end face along the axial direction of the wound electrode group 121 to form the communication hole 1351.

[0138] Since the support structure 13 has opposite third end faces 133 and fourth end faces in the axial direction of the wound electrode group 121, and the cavity 135 axially penetrates through the third end face 133 and / or the fourth end face along the axial direction of the wound electrode group 121, the cavity 135 forms the communication hole 1351 at one or both ends in the axial direction of the wound electrode group 121, facilitating the electrolyte in the cavity 135 to flow into the inner cavity of the housing 11 through the communication hole 1351 at one or both ends in the axial direction of the wound electrode group 121 along the cavity 135, and further facilitating the wound electrode group 121 in the inner cavity to fully contact the electrolyte.

[0139] In the above technical solution, since the support structure 13 has opposite third end faces 133 and fourth end faces in the axial direction of the wound electrode group 121, and the cavity 135 axially penetrates through the third end face 133 and / or the fourth end face along the axial direction of the wound electrode group 121, the cavity 135 forms the communication hole 1351 at one or both ends in the axial direction of the wound electrode group 121, facilitating the electrolyte in the cavity 135 to flow into the inner cavity of the housing 11 through the communication hole 1351 at one or both ends in the axial direction of the wound electrode group 121 along the cavity 135, and further facilitating the wound electrode group 121 in the inner cavity to fully contact the electrolyte.

[0140] Reference Figures 4-6, in some embodiments, the outer peripheral surface of the wound electrode assembly 121 includes two flat portions 1211 and two curved portions 1212. The two flat portions 1211 face each other in the first direction and are spaced apart from each other, and the two curved portions 1212 face each other in the second direction and are spaced apart from each other. The first direction, the second direction, and the axial direction of the wound electrode assembly 121 intersect pairwise. The support structure 13 includes a plurality of support members 136, and at least one support member 136 is provided between each curved portion 1212 and the housing 11.

[0141] For example, the first direction may refer to the X direction in the accompanying drawings, and the second direction may refer to the Y direction in the accompanying drawings.

[0142] By including a plurality of support members 136 in the support structure 13 and providing at least one support member 136 between each curved portion 1212 and the housing 11, each curved portion 1212 of the wound electrode assembly 121 can be effectively supported and constrained by at least one support member 136. In this way, the possibility of cracking of each curved portion 1212 of the wound electrode assembly 121 can be effectively reduced, thereby improving the overall reliability of the battery cell 10.

[0143] In the above technical solution, by including a plurality of support members 136 in the support structure 13 and providing at least one support member 136 between each curved portion 1212 and the housing 11, each curved portion 1212 of the wound electrode assembly 121 can be effectively supported and constrained by the support members 136. In this way, the possibility of cracking of each curved portion 1212 of the wound electrode assembly 121 can be effectively reduced, thereby improving the overall reliability of the battery cell 10.

[0144] Reference Figures 4-6 , in some embodiments, a cavity 135 is provided in the support member 136. The cavity 135 extends along the axial direction of the wound electrode assembly 121. The ratio of the total cross-sectional area of all the cavities 135 of a single support member 136 to the cross-sectional area of the single support member 136 ranges from 0.4 to 0.6.

[0145] For example, the ratio of the total cross-sectional area of all the cavities 135 of a single support member 136 to the cross-sectional area of the single support member 136 can be 0.4, 0.45, 0.5, 0.55, 0.6, etc. By making the ratio of the total cross-sectional area of all the cavities 135 of a single support member 136 to the cross-sectional area of the single support member 136 not less than 0.4, the total cross-sectional area of all the cavities 135 of the single support member 136 can be made larger, so that more electrolyte can be stored in the cavities 135, facilitating sufficient contact between the wound electrode group 121 in the inner cavity of the housing 11 and the electrolyte; by making the ratio of the total cross-sectional area of all the cavities 135 of a single support member 136 to the cross-sectional area of the single support member 136 not greater than 0.6, the support member 136 can have stronger structural strength, so as to effectively support and restrain the wound electrode group 121, and avoid reducing the structural strength of the support member 136 due to the excessive total cross-sectional area of all the cavities 135 of the single support member 136.

[0146] It should be explained that the total cross-sectional area of all the cavities 135 on a single support member 136 refers to: when there is one cavity 135 on a single support member 136, the total cross-sectional area of all the cavities 135 on the single support member 136 is the cross-sectional area of one cavity 135 on the single support member 136; when there are multiple cavities 135 on a single support member 136, the total cross-sectional area of all the cavities 135 on the single support member 136 is the total cross-sectional area of all the cavities 135 on the single support member 136, where the cross-section of the cavity 135 refers to the section obtained by cutting the cavity 135 with a plane perpendicular to the axial direction of the wound electrode group 121.

[0147] The cross-sectional area of a single support member 136 refers to: the area of the figure enclosed by the outer contour line of the cross-section of the single support member 136, where the cross-section of the support member 136 refers to the section obtained by cutting the support member 136 with a plane perpendicular to the axial direction of the wound electrode group 121.

[0148] In the above technical solution, by making the ratio range of the total cross-sectional area of all the cavities 135 of a single support member 136 to the cross-sectional area of the single support member 136 be 0.4 - 0.6, the total cross-sectional area of all the cavities 135 of the single support member 136 can be made larger, so that more electrolyte can be stored in the cavities 135, facilitating sufficient contact between the wound electrode group 121 in the inner cavity of the housing 11 and the electrolyte; and the support member 136 can have stronger structural strength, so as to effectively support and restrain the wound electrode group 121.

[0149] Reference Figures 4-6, in some embodiments, a plurality of cavities 135 are provided in the support member 136, each cavity 135 extends along the axial direction of the wound electrode assembly 121, and the plurality of cavities 135 of a single support member 136 are arranged at intervals in the circumferential direction of the wound electrode assembly 121.

[0150] By providing a plurality of cavities 135 in the support member 136 and each cavity 135 extending along the axial direction of the wound electrode assembly 121, for example, at least a part of the cavity 135 is used for storing electrolyte, and communication holes 1351 are formed at one or both ends of the cavity 135 along the axial direction of the wound electrode assembly 121, the electrolyte in the cavity 135 can be diffused more smoothly to the inner cavity of the housing 11 through the communication holes 1351 at one or both ends along the axial direction of the wound electrode assembly 121, so as to facilitate the contact between the wound electrode assembly 121 and the electrolyte; and, by arranging the plurality of cavities 135 of a single support member 136 at intervals in the circumferential direction of the wound electrode assembly 121, the electrolyte in the cavity 135 can be diffused more evenly to the wound electrode assembly 121, so that each part of the wound electrode assembly 121 can be in contact with the electrolyte more fully, which is beneficial to improving the overall performance of the battery cell 10.

[0151] In the above technical solution, by providing a plurality of cavities 135 in the support member 136 and each cavity 135 extending along the axial direction of the wound electrode assembly 121, for example, at least a part of the cavity 135 is used for storing electrolyte, and communication holes 1351 are formed at one or both ends of the cavity 135 along the axial direction of the wound electrode assembly 121, the electrolyte in the cavity 135 can be diffused more smoothly to the inner cavity of the housing 11 through the communication holes 1351 at one or both ends along the axial direction of the wound electrode assembly 121, so as to facilitate the contact between the wound electrode assembly 121 and the electrolyte; and, by arranging the plurality of cavities 135 of a single support member 136 at intervals in the circumferential direction of the wound electrode assembly 121, the electrolyte in the cavity 135 can be diffused more evenly to the wound electrode assembly 121, so that each part of the wound electrode assembly 121 can be in contact with the electrolyte more fully, which is beneficial to improving the overall performance of the battery cell 10.

[0152] Reference Figures 4-6 , in some embodiments, two support members 136 are provided between each curved surface portion 1212 and the housing 11, and the two support members 136 corresponding to each curved surface portion 1212 are arranged at intervals in the first direction.

[0153] By providing two support members 136 between each curved surface portion 1212 and the housing 11, and the two support members 136 corresponding to each curved surface portion 1212 are arranged at intervals in the first direction, the contact area between the support structure 13 and each curved surface portion 1212 can be increased, thereby effectively increasing the restraint on the expansion deformation of each curved surface portion 1212, so as to effectively reduce the possibility of cracking of the curved surface portion 1212.

[0154] In the above technical solution, by providing two support members 136 between each curved surface portion 1212 and the housing 11, and the two support members 136 corresponding to each curved surface portion 1212 being spaced apart in the first direction, the contact area between the support structure 13 and each curved surface portion 1212 can be increased, thereby effectively increasing the restraint on the expansion deformation of each curved surface portion 1212 and effectively reducing the possibility of cracking of the curved surface portion 1212.

[0155] Reference Figures 4-6 Referring to [[ID=]], in some embodiments, there are multiple wound electrode groups 121, the multiple wound electrode groups 121 are arranged in the first direction, and the support members 136 that are adjacent in the first direction and on the same side in the second direction of two adjacent wound electrode groups 121 are connected.

[0156] By having multiple wound electrode groups 121 arranged in the first direction, the multiple wound electrode groups 121 can improve the energy density of the battery cell 10. By connecting the support members 136 that are adjacent in the first direction and on the same side in the second direction of two adjacent wound electrode groups 121, a continuous and stable support structure 13 can be formed to effectively support and restrain the curved surface portions 1212 of two adjacent wound electrode groups 121, and the connection of adjacent support members 136 can limit the adjacent wound electrode groups 121 and reduce or avoid the possibility of the adjacent wound electrode groups 121 moving in the first direction.

[0157] In addition, the connection of adjacent support members 136 can simplify the assembly process. When assembling the battery cell 10, the two support members 136 can be connected first, and then the connected two support members 136 can be installed between the curved surface portions 1212 of two adjacent wound electrode groups 121, which is beneficial to improving the assembly efficiency.

[0158] In the above technical solution, by connecting the support members 136 that are adjacent in the first direction and on the same side in the second direction of two adjacent wound electrode groups 121, a continuous and stable support structure 13 can be formed to effectively support and restrain the curved surface portions 1212 of two adjacent wound electrode groups 121, and the connection of adjacent support members 136 can limit the adjacent wound electrode groups 121 and reduce or avoid the possibility of the adjacent wound electrode groups 121 moving in the first direction.

[0159] Reference Figures 4-6 Referring to [[ID=]], in some embodiments, the support members 136 that are adjacent in the first direction and on the same side in the second direction of two adjacent wound electrode groups 121 are integrally formed.

[0160] By integrally forming the support members 136 that are adjacent to each other in the first direction and located on the same side in the second direction of two adjacent wound electrode groups 121, to a certain extent, the structural strength of the overall adjacent support members 136 of the two adjacent wound electrode groups 121 that are located on the same side in the second direction and adjacent in the first direction can be enhanced, and the assembly process of the adjacent support members 136 between the two adjacent wound electrode groups 121 can also be omitted, thereby improving the overall assembly efficiency of the battery device 100.

[0161] In the above technical solution, by integrally forming the support members 136 that are adjacent to each other in the first direction and located on the same side in the second direction of two adjacent wound electrode groups 121, to a certain extent, the structural strength of the overall adjacent support members 136 of the two adjacent wound electrode groups 121 that are located on the same side in the second direction and adjacent in the first direction can be enhanced, and the assembly process of the adjacent support members 136 between the two adjacent wound electrode groups 121 can also be omitted, thereby improving the overall assembly efficiency of the battery device 100.

[0162] Reference Figure 7 Second, the present application proposes a battery device 100, including a box body and a battery cell 10 according to the first aspect embodiment of the present application, and the battery cell 10 is disposed in the box body.

[0163] In the above technical solution, by providing the above battery cell 10, the battery device 100 can have high reliability and good performance.

[0164] Reference Figure 8 Third, the present application proposes an electrical device 1000, including the battery device 100 according to the second aspect embodiment of the present application.

[0165] Among them, the electrical device 1000 can be a vehicle, and the battery device 100 can be installed at the bottom of the vehicle body 200.

[0166] For example, the battery device 100 can be disposed at the bottom of the vehicle body 200. When the battery device 100 is used for a vehicle, the up-down direction can refer to the Z direction in the drawings.

[0167] In the above technical solution, by providing the above battery device 100, the electrical device 1000 can have high reliability and good performance.

[0168] Next, refer to Figures 1-6 to describe the battery cell 10 according to some embodiments of the present application.

[0169] In this embodiment, the battery cell 10 includes a housing 11, an electric machine assembly, and a support structure 13. The electrode assembly 12 is disposed within the housing 11 and includes at least one wound electrode group 121. The outer circumferential surface of the wound electrode group 121 includes a flat portion 1211 and a curved portion 1212. In the circumferential direction of the wound electrode group 121, the flat portion 1211 extends linearly, and the curved portion 1212 extends along a curve. The support structure 13 is disposed within the housing 11 and is located between the outer circumferential side of the wound electrode group 121 and the housing 11. At least a portion of the support structure 13 is located between the curved portion 1212 and the housing 11.

[0170] The surface of the support structure 13 facing the wound electrode group 121 constitutes a constraint surface 131. The constraint surface 131 is in contact with or connected to the curved portion 1212, and the constraint surface 131 has the same shape as the curved portion 1212. In the circumferential direction of the wound electrode group 121, both the constraint surface 131 and the curved portion 1212 extend along an arc. The ratio of the radius of curvature of the constraint surface 131 to the radius of curvature of the curved portion 1212 ranges from 0.9 to 1.1.

[0171] The support structure 13 is in contact with or connected to the housing 11. The surface of the inner wall of the housing 11 facing the support structure 13 is a first side wall surface 111, and the surface of the support structure 13 facing the inner wall of the housing 11 is a second side wall surface 132. Both the first side wall surface 111 and the second side wall surface 132 are flat surfaces.

[0172] The wound electrode group 121 includes an electrode group main body 1213 and an electrode tab 1214. The electrode tab 1214 is connected to the axial side of the electrode group main body 1213. The ratio of the height dimension of the support structure 13 in the axial direction of the wound electrode group 121 to the height dimension of the electrode group main body 1213 in the axial direction of the wound electrode group 121 ranges from 0.7 to 1.0.

[0173] The wound electrode group 121 includes an electrode group main body 1213 and an electrode tab 1214. The electrode tab 1214 is connected to the axial side of the electrode group main body 1213. The electrode group main body 1213 has opposite first and second end faces in the axial direction of the wound electrode group 121. The support structure 13 has opposite third and fourth end faces in the axial direction of the wound electrode group 121. The first end face 1215 and the third end face 133 are located on the same side in the axial direction of the wound electrode group 121. The third end face 133 is flush with the first end face 1215 or the plane of the third end face 133 is located on the side closer to the second end face than the plane of the first end face 1215. The second end face and the fourth end face are located on the same side in the axial direction of the wound electrode group 121. The fourth end face is flush with the second end face or the plane of the fourth end face is located on the side closer to the first end face 1215 than the plane of the second end face.

[0174] The support structure 13 is a plastic structure or an insulating glue structure. A cavity 135 is provided inside the support structure 13, and at least part of the cavity 135 is used to store electrolyte. The cavity 135 extends along the axial direction of the wound electrode group 121. The support structure 13 has opposite third end faces 133 and fourth end faces in the axial direction of the wound electrode group 121, and the cavity 135 axially penetrates the third end face 133 and / or the fourth end face along the wound electrode group 121 to form a communication hole 1351, and the communication hole 1351 is used to communicate the cavity 135 with the inner cavity of the housing 11.

[0175] The outer peripheral surface of the wound electrode group 121 includes two flat portions 1211 and two curved portions 1212. The two flat portions 1211 are opposite and spaced apart in a first direction, and the two curved portions 1212 are opposite and spaced apart in a second direction. The first direction, the second direction, and the axial direction of the wound electrode group 121 intersect pairwise. The support structure 13 includes a plurality of support members 136, and at least one support member 136 is provided between each curved portion 1212 and the housing 11.

[0176] A plurality of cavities 135 are provided inside the support member 136, and each cavity 135 extends along the axial direction of the wound electrode group 121. The cavities 135 of a single support member 136 are spaced apart circumferentially along the wound electrode group 121. The ratio of the total cross-sectional area of all the cavities 135 of a single support member 136 to the cross-sectional area of the single support member 136 ranges from 0.4 to 0.6.

[0177] Two support members 136 are provided between each curved portion 1212 and the housing 11, and the two support members 136 corresponding to each curved portion 1212 are spaced apart in the first direction. There are a plurality of wound electrode groups 121, and the plurality of wound electrode groups 121 are arranged in the first direction. The support members 136 that are adjacent in the first direction and on the same side in the second direction of two adjacent wound electrode groups 121 are connected. The support members 136 that are adjacent in the first direction and on the same side in the second direction of two adjacent wound electrode groups 121 are integrally formed.

[0178] By providing the support structure 13 inside the housing 11 and at least part of the support structure 13 being located between the curved portion 1212 of the wound electrode group 121 and the housing 11, the expansion deformation constraint on the curved portion 1212 can be increased, the possibility of cracking of the electrode sheet corresponding to the curved portion 1212 can be reduced, and further the possibility of short circuit of the battery cell 10 caused by electrode sheet cracking can be reduced or avoided, which is beneficial to improving the reliability and safety of the battery cell 10.

[0179] In the description of this specification, the descriptions with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples", etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples.

[0180] Although the embodiments of the present application have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that, Comprising: A housing; An electrode assembly disposed within the housing and including at least one wound electrode group, an outer circumferential surface of the wound electrode group including a flat portion and a curved portion, in a circumferential direction of the wound electrode group, the flat portion extending linearly and the curved portion extending along a curve; A support structure disposed within the housing and located between an outer circumferential side of the wound electrode group and the housing, at least a part of the support structure being located between the curved portion and the housing, a surface of the support structure facing the wound electrode group constituting a constraint surface, the constraint surface being in contact with or connected to the curved portion.

2. The battery cell according to claim 1, characterized in that, The constraint surface has the same shape as the curved portion.

3. The battery cell according to claim 1, characterized in that, In the circumferential direction of the wound electrode group, both the constraint surface and the curved portion extend along an arc.

4. The battery cell according to claim 3, wherein, A ratio range of a radius of curvature of the constraint surface to a radius of curvature of the curved portion is 0.9 to 1.

1.

5. The battery cell according to claim 1, characterized in that The support structure is in contact with or connected to the housing.

6. The battery cell according to claim 5, characterized in that A surface of an inner wall of the housing facing the support structure is a first side wall surface, a surface of the support structure facing the inner wall of the housing is a second side wall surface, and both the first side wall surface and the second side wall surface are flat surfaces.

7. The battery cell according to claim 1, wherein The wound electrode group includes an electrode group main body and an electrode tab, the electrode tab being connected to an axial side of the electrode group main body, a ratio range of a height dimension of the support structure in an axial direction of the wound electrode group to a height dimension of the electrode group main body in the axial direction of the wound electrode group being 0.7 to 1.

0.

8. The battery cell according to claim 1, characterized in that, The wound electrode group includes an electrode group main body and an electrode tab, the electrode tab being connected to an axial side of the electrode group main body, the electrode group main body having opposite first and second end faces in an axial direction of the wound electrode group, the support structure having opposite third and fourth end faces in the axial direction of the wound electrode group, the first end face and the third end face being on the same side in the axial direction of the wound electrode group, the third end face being flush with the first end face or a plane where the third end face is located being on a side close to the second end face of a plane where the first end face is located, the second end face and the fourth end face being on the same side in the axial direction of the wound electrode group, the fourth end face being flush with the second end face or a plane where the fourth end face is located being on a side close to the first end face of a plane where the second end face is located.

9. The battery cell according to claim 1, characterized in that, The support structure is an insulating structure or a surface layer structure of the support structure is an insulating structure.

10. The battery cell according to claim 9, characterized in that, The support structure is a plastic structure or an insulating glue structure.

11. The battery cell according to claim 1, wherein A cavity is provided within the support structure.

12. The battery cell according to claim 11, characterized in that, The cavity extends along the axial direction of the wound electrode group.

13. The battery cell according to claim 11, characterized in that, A communication hole communicating the cavity with an inner cavity of the housing is further provided on the support structure, and at least a part of the cavity is used for storing electrolyte.

14. The battery cell according to claim 13, characterized in that, The support structure has opposite third and fourth end faces in the axial direction of the wound electrode group, and the cavity axially penetrates through the third end face and / or the fourth end face along the axial direction of the wound electrode group to form the communication hole.

15. The battery cell according to any one of claims 1-10, characterized in that, The outer peripheral surface of the wound electrode group includes two flat portions and two curved portions. The two flat portions are opposite and spaced apart in a first direction. The two curved portions are opposite and spaced apart in a second direction. The first direction, the second direction, and the axial direction of the wound electrode group intersect pairwise. The support structure includes a plurality of support members, and at least one support member is provided between each curved portion and the housing.

16. The battery cell according to claim 15, wherein A cavity is provided in the support member, and the cavity extends along the axial direction of the wound electrode group. The ratio of the total cross-sectional area of all the cavities of a single support member to the cross-sectional area of the single support member ranges from 0.4 to 0.

6.

17. The battery cell according to claim 15, wherein, A plurality of cavities are provided in the support member, and each cavity extends along the axial direction of the wound electrode group. The plurality of cavities of a single support member are spaced apart circumferentially along the wound electrode group.

18. The battery cell according to claim 15, characterized in that, Two support members are provided between each curved portion and the housing, and the two support members corresponding to each curved portion are spaced apart in the first direction.

19. The battery cell according to claim 15, characterized in that, There are a plurality of the wound electrode groups, and the plurality of wound electrode groups are arranged in the first direction. The support members that are on the same side in the second direction and adjacent in the first direction between two adjacent wound electrode groups are connected.

20. The battery cell according to claim 19, characterized in that, The support members that are on the same side in the second direction and adjacent in the first direction between two adjacent wound electrode groups are integrally formed.

21. A battery device, characterized in that, Comprising: A box body; And the battery cell according to any one of claims 1-20, the battery cell being disposed in the box body.

22. An electrical device, characterized in that, Including the battery device according to claim 21.

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