Battery cell, battery device, and electric device

Abstract

This application relates to a battery cell, a battery device, and an electrical device. The battery cell includes an end cap, which comprises a cap body and at least one functional component. The cap body has mounting holes corresponding to the functional component, and the functional component is mounted in the corresponding mounting holes. The cap body also has a buffer groove structure corresponding to the functional component, which surrounds the corresponding functional component. When the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the buffer groove structure can deform in conjunction with the weak part, effectively dispersing stress, reducing stress concentration in the area where the functional component is located, and thus reducing the risk of failure of the weak part.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to battery cells, battery devices, and electrical devices. Background Technology

[0002] As the application of batteries continues to expand, the market demand is also increasing. The market demand for battery safety performance is getting higher and higher, and the safety and reliability of individual battery cells also need to be further improved.

[0003] Battery cell end caps often have some weak points. When a battery cell is subjected to impact or undergoes cyclic expansion during charging and discharging, the stress on the end cap is easily concentrated in these weak points, which can easily lead to failure of these weak points. Utility Model Content

[0004] In view of the above problems, this application provides a battery cell, a battery device and an electrical device, which can reduce the stress concentration of weak parts when the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, thereby reducing the risk of failure of weak parts.

[0005] In a first aspect, embodiments of this application provide a battery cell, the battery cell including an end cap, the end cap including a cap body and at least one functional component, the cap body having mounting holes corresponding to the functional component, the functional component being mounted in the corresponding mounting holes;

[0006] The cover body is provided with a buffer groove structure corresponding to the functional component, and the buffer groove structure surrounds the corresponding functional component.

[0007] The aforementioned battery cell has mounting holes on its cover corresponding to functional components, which are then installed in these holes. The junction between the functional component and the corresponding mounting hole is a weak point. The cover also features a buffer groove structure corresponding to the functional component. By incorporating this buffer groove structure, the strength of the area on the cover with the buffer groove structure is reduced, while its toughness is increased, i.e., its deformation capacity is enhanced. Since the buffer groove structure surrounds the corresponding functional component, it essentially forms a buffer zone around the functional component on the cover. Thus, when the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the buffer groove structure can effectively disperse stress, reducing stress concentration at the junction of the functional component and the corresponding mounting hole, thereby lowering the risk of failure at this weak point.

[0008] In one embodiment, the buffer groove structure is a first type of buffer groove structure or a second type of buffer groove structure;

[0009] The first type of buffer groove structure includes at least one circumferential buffer groove, the circumferential buffer groove extending along the circumference of the functional component and surrounding the functional component.

[0010] The second type of buffer groove structure includes multiple linear buffer grooves distributed around the functional component, and at least some of the virtual extension lines of the linear buffer grooves form an angle with the outline of the mounting hole.

[0011] By making the buffer groove structure the first type or the second type of buffer groove structure mentioned above, the buffer groove structure can play a more sufficient buffering role, more effectively disperse stress, reduce the stress concentration in the area where the functional components are located, and thus reduce the risk of failure of weak parts.

[0012] In one embodiment, multiple linear buffer grooves are parallel to each other.

[0013] In one embodiment, multiple linear buffer grooves are parallel to each other along the length or width of the cover body.

[0014] In one embodiment, the first type of buffer groove structure includes multiple circumferential buffer grooves, which surround each other from the inside out.

[0015] Multiple circumferential buffer grooves are arranged around the electrode terminals from the inside out, forming multiple buffer bands around the electrode terminals. When the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, these multiple buffer bands can distribute the force, further reducing the stress concentration at the sealing joint between the terminal post and the electrode lead hole wall, and further reducing the risk of seal failure at the joint between the terminal post and the electrode lead hole.

[0016] In one embodiment, the circumferential buffer groove is a continuous buffer groove; or, the circumferential buffer groove includes a plurality of groove segments arranged at circumferential intervals along the functional component.

[0017] In one embodiment, the first type of buffer groove structure further includes an additional buffer groove, and at least one additional buffer groove is provided on at least one side of the circumferential buffer groove along the length direction of the cover body.

[0018] The addition of a buffer groove can further enhance the deformation capacity of the cover body in the area around the electrode post. The additional buffer groove can further disperse stress, further reduce the stress concentration at the sealing joint between the electrode post and the electrode lead-out hole wall, and further reduce the risk of sealing failure at the joint between the electrode post and the electrode lead-out hole.

[0019] In one embodiment, the plurality of buffer linear grooves include a plurality of first linear grooves and a plurality of second linear grooves. The plurality of first linear grooves are parallel to each other along a first direction, and the plurality of second linear grooves are parallel to each other along a second direction. The first direction and the second direction intersect.

[0020] By setting multiple first linear grooves and multiple second linear grooves, with the first linear grooves extending along the width of the cover body and the second linear grooves extending along the length of the cover body, the projections of the multiple first linear grooves and multiple second linear grooves form a grid, which can more effectively enhance the deformation capacity of the buffer groove structure and more effectively disperse stress, further reducing the failure risk of weak parts.

[0021] In one embodiment, a circumferential buffer groove adjacent to the functional component is provided on the side of the cover body facing outward from the battery cell, and the third direction is the thickness direction of the cover body.

[0022] Because the force on the functional component under the bottom ball impact condition is from the outside to the inside along the thickness direction of the cover body, placing the circumferential buffer groove adjacent to the functional component on the side of the cover body facing outward from the battery cell can make the force direction of the functional component the same as the groove depth direction of the circumferential buffer groove, thereby achieving a better buffering and energy absorption effect.

[0023] In one embodiment, the cover body is provided with a liquid injection hole; the buffer groove structure has a break zone on the side near the liquid injection hole, and the distance between the two ends of the break zone is greater than or equal to the diameter of the liquid injection hole.

[0024] The buffer groove structure has a break zone on the side near the injection hole. The distance between the two ends of the break zone is greater than or equal to the diameter of the injection hole, so that the buffer groove structure can maintain a distance from the injection hole as much as possible, thereby minimizing the weakening of strength near the injection hole.

[0025] In one embodiment, the buffer groove structure is located on the side of the cover body facing outwards from the battery cell in a third direction; or,

[0026] The buffer groove structure is located on the side of the cover body facing the inside of the battery cell in a third direction; or,

[0027] The buffer groove structure is divided into a first buffer groove and a second buffer groove. The first buffer groove is located on the side of the cover body facing outwards from the battery cell along a third direction, and the second buffer groove is located on the side of the cover body facing inwards from the battery cell along a third direction.

[0028] Among them, the third direction is the thickness direction of the cover body.

[0029] This embodiment divides the buffer groove structure into two parts located on both sides of the cover body, thus forming a buffer zone on both sides of the cover body. This further enhances the deformation capacity of the cover body in the area surrounding the functional components, thereby further dispersing stress and reducing the risk of failure of weak parts.

[0030] In one embodiment, the projections of the first buffer groove and the second buffer groove along the thickness direction of the cover body are completely offset or partially overlap.

[0031] By completely offsetting or partially overlapping the projections of the first and second buffer grooves along the thickness direction of the cover body, the overlapping area of ​​the first and second buffer grooves on the cover body can be minimized. The cover body is weaker in the overlapping area, thus minimizing the situation where the buffer groove structure on the cover body is weak in a local area.

[0032] In one embodiment, the depth t1 of the first buffer groove satisfies the condition: 0.5t ≥ t1 ≥ 0.02t, and the depth t2 of the second buffer groove satisfies the condition: 0.5t ≥ t2 ≥ 0.02t, where t is the thickness of the cover body. The value range of t is: 1.5mm ≥ t ≥ 3mm; the value range of t1 is: 0.3mm ≥ t1 ≥ 1mm; and the value range of t2 is: 0.3mm ≥ t2 ≥ 1mm.

[0033] By setting 0.5t≥t1≥0.02t and 0.5t≥t2≥0.02t, the first and second buffer grooves can ensure that the cover body has good deformation capacity and that the strength of the cover body in the first and second buffer grooves is appropriate and not weakened too much.

[0034] In one embodiment, the depth of the buffer groove structure is uniform and constant; or, the depth of the buffer groove structure varies according to the distance to the functional component, the depth is smaller.

[0035] In one embodiment, the buffer groove structure is divided into a first buffer groove and a second buffer groove. The first buffer groove is located on the side of the cover body facing outward from the battery cell along a third direction, and the second buffer groove is located on the side of the cover body facing inward from the battery cell along a third direction.

[0036] The depth t1 of the first part of the buffer groove is uniform and constant; or, the depth t1 of the first part of the buffer groove varies according to the law that the farther away from the functional component, the smaller t1 is.

[0037] The depth t2 of the second buffer groove is uniform and constant; or, the depth t2 of the second buffer groove varies according to the distance to the functional component, the smaller t2 is.

[0038] This embodiment achieves this by varying the depth of the buffer groove structure such that the greater the distance to the functional component, the shallower the depth; conversely, the closer to the functional component, the deeper the depth. This results in a stronger buffering capacity in the area closer to the functional component, effectively cushioning the vicinity and reducing the risk of failure at weak points. Simultaneously, because the buffer groove's depth decreases with distance from the functional component, it minimizes any weakening of the cover body's strength.

[0039] In one embodiment, the distance between any two adjacent and parallel buffer slots is defined as d2;

[0040] The variation law of d2 is that the farther the distance to the functional component, the smaller d2 becomes; or, d2 is uniform and constant.

[0041] The farther away from the functional components, the sparser the arrangement of the buffer grooves; conversely, the closer to the functional components, the denser the arrangement of the buffer grooves. This allows the buffer groove structure to have a stronger buffering capacity in the area closer to the functional components, effectively cushioning the vicinity of the functional components and reducing the risk of failure at weak points. At the same time, because the buffer grooves are more sparsely arranged with distance from the functional components, the weakening of the cover body's strength can be minimized.

[0042] In one embodiment, the distance d1 from the buffer groove structure to the edge of the cover body satisfies the condition: d1≥0.8mm.

[0043] In this embodiment, by ensuring that the distance d1 between the buffer groove structure and the edge of the cover body meets the condition: d1≥0.8mm, the distance d1 between the buffer groove structure and the edge of the cover body can be appropriate, thereby ensuring the welding quality between the edge of the cover body and the shell.

[0044] In one embodiment, at least one functional component is an electrode terminal; the cover body is provided with an electrode lead-out hole, and the mounting hole corresponding to the electrode terminal is the electrode lead-out hole;

[0045] The electrode terminal includes a post and a rivet. At least a portion of the post passes through the electrode lead-out hole. The rivet is located on the side of the cover body facing outward from the battery cell along the thickness direction of the cover body. The rivet is connected to the post and is used to rivet the post to the cover body.

[0046] The cover body is provided with a buffer groove structure surrounding the electrode terminals. The buffer groove structure surrounding the electrode terminals is either a first type of buffer groove structure or a second type of buffer groove structure.

[0047] Because a buffer groove structure is provided around the electrode terminals, the buffer groove structure forms a buffer zone around the electrode post. When the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the stress concentration at the sealing joint between the electrode post and the electrode lead hole wall can be reduced due to the deformation of the buffer zone, thereby reducing the risk of sealing failure at the joint between the electrode post and the electrode lead hole.

[0048] In one embodiment, the battery cell further includes an insulating member disposed between the riveting member and the cover body along the thickness direction of the cover body;

[0049] Along the direction perpendicular to the thickness of the cover body, the distance from the buffer groove structure surrounding the electrode terminal to the insulating component is greater than 1 mm.

[0050] In this embodiment, by ensuring that the distance between the buffer groove structure surrounding the electrode terminal and the insulating component is greater than 1 mm along a direction perpendicular to the thickness of the cover body, a suitable distance can be maintained between the buffer groove structure and the insulating component. This allows the buffer groove structure to effectively disperse stress around the electrode post while ensuring that the buffer groove structure does not affect the assembly of the insulating component and the cover body.

[0051] In one embodiment, at least one functional component is a pressure relief mechanism, and the cover body is provided with a pressure relief mechanism mounting hole, and the pressure relief mechanism is installed in the pressure relief mechanism mounting hole;

[0052] The cover body is provided with a buffer groove structure surrounding the pressure relief mechanism. The buffer groove structure surrounding the pressure relief mechanism is either a first type of buffer groove structure or a second type of buffer groove structure.

[0053] Because the pressure relief mechanism is surrounded by a buffer groove structure, a buffer zone is formed around the pressure relief mechanism. When the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the joint between the pressure relief mechanism and its corresponding mounting hole can reduce the stress concentration due to the deformation of the buffer zone, thereby reducing the risk of pressure relief mechanism installation failure.

[0054] In one embodiment, a protective patch is also installed in the mounting hole of the pressure relief mechanism, and the pressure relief mechanism is located on the side of the protective patch close to the inside of the battery cell along the thickness direction of the cover body.

[0055] Along the direction perpendicular to the thickness of the cover body, the portion of the buffer groove structure surrounding the pressure relief mechanism located on the side of the cover body facing the battery cell along the thickness of the cover body is more than 1 mm away from the pressure relief mechanism.

[0056] In this embodiment, the portion of the buffer groove structure surrounding the pressure relief mechanism on the side of the cover body facing the battery cell, perpendicular to the thickness direction of the cover body, is at a distance greater than 1mm from the pressure relief mechanism. This ensures that the portion of the buffer groove structure surrounding the pressure relief mechanism on the side of the cover body facing the battery cell has sufficient distance from the pressure relief mechanism, thereby reducing the impact on the assembly of the pressure relief mechanism and reducing the problem of poor sealing at the pressure relief mechanism.

[0057] In one embodiment, a boss protruding outward along the thickness direction of the cover body is provided on the cover body, and the boss is arranged around the circumferential edge of the pressure relief mechanism mounting hole.

[0058] The portion of the buffer groove structure surrounding the pressure relief mechanism, located on the side of the cover body facing outwards from the battery cell along the thickness direction of the cover body, is situated around the boss.

[0059] By positioning the portion of the buffer groove structure surrounding the pressure relief mechanism on the side of the cover body facing the battery cell outside the cover body, and offset from the boss, the buffer groove structure does not extend into the boss, thus keeping the boss intact and effectively providing a barrier.

[0060] Secondly, embodiments of this application provide a battery device, including a battery box and any of the aforementioned battery cells, wherein the battery cells are located inside the battery box.

[0061] In the aforementioned battery device, the cover body has mounting holes corresponding to functional components, which are then installed in these holes. The junction between the functional component and the corresponding mounting hole is a weak point. The cover body also has a buffer groove structure corresponding to the functional component. By providing the buffer groove structure, the strength of the area on the cover body with the buffer groove structure is reduced, while the toughness is increased, i.e., the deformation capacity is enhanced. Since the buffer groove structure surrounds the corresponding functional component, it surrounds the junction between the functional component and the corresponding mounting hole, thus the buffer groove structure is equivalent to a buffer zone formed around the functional component on the cover body. In this way, when the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the buffer groove structure can effectively disperse stress, reduce the stress concentration at the junction between the functional component and the corresponding mounting hole, and thereby reduce the risk of failure at the junction (i.e., the weak point).

[0062] Thirdly, embodiments of this application provide an electrical device, including a battery device, which provides electrical energy to the electrical device.

[0063] The aforementioned electrical device has mounting holes on its cover corresponding to functional components, which are then installed in these holes. The junction between the functional component and the corresponding mounting hole is a weak point. The cover also has a buffer groove structure corresponding to the functional component. By providing the buffer groove structure, the strength of the area on the cover with the buffer groove structure is reduced, while its toughness is increased, i.e., its deformation capacity is enhanced. Since the buffer groove structure surrounds the corresponding functional component, it essentially forms a buffer zone around the functional component on the cover. Thus, when the battery cell is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the buffer groove structure can effectively disperse stress, reducing stress concentration at the junction of the functional component and the corresponding mounting hole, thereby reducing the risk of failure at the junction (i.e., the weak point).

[0064] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0065] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0066] Figure 1 This is a schematic diagram of the structure of a vehicle according to some embodiments of this application.

[0067] Figure 2 This is an exploded view of the battery device according to some embodiments of this application.

[0068] Figure 3 This is an exploded structural diagram of a battery cell according to some embodiments of this application.

[0069] Figure 4 This is a schematic diagram of the end cap of a battery cell according to some embodiments of this application.

[0070] Figure 5 for Figure 4 The structure explodes.

[0071] Figure 6 for Figure 4 Top view.

[0072] Figure 7 for Figure 6A magnified view of a portion of point A in the middle.

[0073] Figure 8 for Figure 6 A magnified view of a section at point B in the middle.

[0074] Figure 9 for Figure 6 AA cross-section view.

[0075] Figure 10 for Figure 9 A magnified view of a section at point C.

[0076] Figure 11 for Figure 10 A schematic diagram of the main body of the middle cover.

[0077] Figure 12 This is a top view of the end cap of a battery cell according to other embodiments of this application.

[0078] Figure 13 This is a top view of the end cap of a battery cell according to some embodiments of this application.

[0079] Figure 14 for Figure 13 A magnified view of a section at point D.

[0080] Figure 15 for Figure 13 BB cross-section.

[0081] Figure 16 for Figure 15 A magnified view of a section at point E in the middle.

[0082] Figure 17 for Figure 15 A schematic diagram of the main body of the middle cover.

[0083] Figure 18 for Figure 13 Bottom view of the middle end cap.

[0084] Figure 19 This is a top view of the end cap of a battery cell according to another embodiment of this application.

[0085] Figure 20 for Figure 19 CC section view.

[0086] Figure 21 This is a top view of the end cap of a battery cell according to another embodiment of this application.

[0087] Figure 22 for Figure 21 A magnified view of a section at point F.

[0088] Figure 23 yes Figure 21 DD sectional view.

[0089] Figure 24 This is a top view of the end cap of a battery cell according to some other embodiments of this application.

[0090] Figure 25 for Figure 24 Bottom view of the middle end cap.

[0091] Figure 26 This is a top view of the end cap of a battery cell according to some other embodiments of this application.

[0092] Figure 27 for Figure 26 A magnified view of a section at point G.

[0093] Figure 28 for Figure 26 EE sectional view.

[0094] The reference numerals in the detailed embodiments are as follows:

[0095] 1-Vehicle;

[0096] 10-Battery Device;

[0097] 100 - Battery box; 110 - Box body; 120 - Top cover;

[0098] 200. Battery cell;

[0099] 210 - Casing;

[0100] 220 - End cap; 221 - Cap body; 222 - Pole post; 223 - Pressure relief mechanism; 2231 - Protective patch; 224 - Riveting component; 225 - Insulating component; 226 - Boss;

[0101] 201. Buffer groove structure; 201a. Buffer groove structure surrounding the electrode terminal; 2011. Circumferential buffer groove; 2011a. First circumferential buffer groove; 2011b. Second circumferential buffer groove; 2012. Additional buffer groove; 2013. Linear buffer groove;

[0102] 201b, a buffer groove structure surrounding the pressure relief mechanism 223; 2013a, a first linear groove; 2013b, a second linear groove;

[0103] 202. Electrode lead-out hole;

[0104] 203, Injection Hole; 203a, Disconnection Zone;

[0105] 204. Pressure relief mechanism mounting hole;

[0106] 230 - Electrode assembly;

[0107] 20-Controller;

[0108] 30-Motor. Detailed Implementation

[0109] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0110] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0111] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0112] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0113] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0114] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0115] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0116] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0117] Currently, the application of batteries is becoming increasingly widespread in the market. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing. The market demands higher safety performance from batteries, and the safety and reliability of individual battery cells need further improvement.

[0118] A typical battery cell end cap consists of a cap body and functional components. The cap body has mounting holes for installing the functional components. Compared to other parts of the cap body, the joint between the functional components and the mounting holes is relatively weak. When the battery cell is subjected to impact or undergoes cyclic expansion during charging and discharging, the stress on the end cap is easily concentrated at its weakest point, which can easily lead to failure of the weakest part.

[0119] For example, the functional component is the electrode terminal. The joint between the electrode terminal and the electrode terminal mounting hole is a weak point. When the battery cell is subjected to impact or when it undergoes cyclic expansion during charging and discharging, the stress on the end cap is easily concentrated at the joint between the electrode terminal and the electrode terminal mounting hole, which can easily lead to the failure of the seal between the electrode terminal and the electrode terminal mounting hole.

[0120] For example, if the functional component is a pressure relief mechanism, the joint between the pressure relief mechanism and the pressure relief mechanism mounting hole is a weak point. When the battery cell is subjected to impact or when it undergoes cyclic expansion during charging and discharging, the force on the end cap is easily concentrated at the joint between the pressure relief mechanism and the pressure relief mechanism mounting hole, which can easily lead to the failure of the pressure relief mechanism installation.

[0121] Based on the above considerations, this application provides a battery cell, battery device, and power supply device as described above. By providing a buffer groove structure 201 surrounding the functional component, the buffer groove structure 201 is equivalent to a buffer zone formed around the functional component on the cover body 221. Thus, when the battery cell 200 is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the buffer groove structure 201 can effectively disperse stress, reduce the stress concentration at the joint between the functional component and the corresponding mounting hole, and thereby reduce the risk of failure at the joint between the functional component and the corresponding mounting hole (i.e., the weak point).

[0122] The battery device disclosed in this application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. Specifically, the electrical device can be, but is not limited to, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc. By using the battery device disclosed in this application to form the power system of the electrical device, the weight of the battery device can be reduced.

[0123] Please refer to Figure 1 , Figure 1 The diagram illustrates the structure of a vehicle 1 according to some embodiments of this application. Vehicle 1 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 10 is installed inside vehicle 1, and the battery device 10 can be located at the bottom, front, or rear of vehicle 1. The battery device 10 can be used to power vehicle 1; for example, the battery device 10 can serve as the operating power source for vehicle 1. Vehicle 1 may also include a controller 20 and a motor 30. The controller 20 controls the battery device 10 to supply power to the motor 30, for example, to meet the power needs of vehicle 1 during starting, navigation, and driving.

[0124] In some embodiments of this application, the battery device 10 can not only serve as the operating power source for the vehicle 1, but also as the driving power source for the vehicle 1, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1.

[0125] Please refer to Figure 2 , Figure 2This is an exploded view of a battery provided in some embodiments of this application. The battery device 10 includes a battery case 100 and battery cells 200. The battery cells 200 are housed within the battery case 100. The battery case 100 provides a space for the battery cells 200, and the battery case can have various structures. In some embodiments, the battery case 100 may include a top cover 120 and a body 110, with the top cover 120 and body 110 overlapping each other, together defining a cavity for accommodating the battery cells 200. The body 110 may be a hollow structure with one open end, and the top cover 120 may be a plate-like structure, fitting over the open side of the body 110 so that the top cover 120 and body 110 together define the cavity; alternatively, both the top cover 120 and body 110 may be hollow structures with one open side, with the open side of the top cover 120 fitting over the open side of the body 110. Of course, the battery box 100 formed by the top cover 120 and the box body 110 can be of various shapes, such as cylinder, cuboid, etc.

[0126] In the battery device 10, there can be multiple battery cells 200, which can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 200 are connected in both series and parallel connections. Multiple battery cells 200 can be directly connected in series, parallel, or in a mixed configuration, and then the entire assembly of the multiple battery cells 200 is housed within the battery box 100. Alternatively, the battery device 10 can also consist of multiple battery cells 200 first connected in series, parallel, or in a mixed configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the battery box 100. The battery device may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 200.

[0127] Each battery cell 200 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The battery cell 200 can be cylindrical, flat, cuboid, or other shapes.

[0128] Please see Figure 3 , Figure 3 It shows Figure 2 The diagram shows an exploded view of a single battery cell 200. The single battery cell 200 refers to the smallest unit that makes up the battery assembly 10. Figure 3 The battery cell 200 includes a housing 210, an end cap 220, an electrode assembly 230, and other functional components.

[0129] End cap 220 refers to a component that covers the opening of housing 210 to isolate the internal environment of battery cell 200 from the external environment. End cap 220 includes cap body 221, on which functional components such as electrode terminals and pressure relief mechanism 223 may be provided. In any case, the shape of cap body 221 can be adapted to the shape of housing 210 to fit the housing 210. Optionally, cap body 221 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that cap body 221 is not easily deformed when subjected to compression and impact, so that battery cell 200 can have higher structural strength and improved safety performance. Terminal post 222 can be used to electrically connect with electrode assembly 230 for outputting or inputting electrical energy of battery cell 200. The material of cap body 221 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose special limitations on this.

[0130] The housing 210 is a component used to cooperate with the end cap 220 to form the internal environment of the battery cell 200, wherein the formed internal environment can accommodate the electrode assembly 230, electrolyte, and other components. The housing 210 and the end cap body 221 can be independent components. An opening can be provided on the housing 210, and the end cap 220 closes the opening to form the internal environment of the battery cell 200. Alternatively, the end cap body 221 and the housing 210 can be integrated. Specifically, the end cap body 221 and the housing 210 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 210, the end cap body 221 closes the housing 210. The housing 210 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 210 can be determined according to the specific shape and size of the electrode assembly 230. The shell 210 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. This application embodiment does not impose any special restrictions on this.

[0131] Electrode assembly 230 is the component in the battery cell 200 where electrochemical reactions occur. The casing 210 may contain one or more electrode assemblies 230. The electrode assembly 230 is mainly formed by stacking composite strips, which are formed by thermally bonding a positive electrode sheet, a negative electrode sheet, and a separator disposed between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body of the electrode assembly 230, while the portions of the positive and negative electrode sheets without active material each constitute a tab. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery device 10, the positive and negative active materials react with the electrolyte, and the tabs connect to the terminals to form a current circuit.

[0132] Figure 4This is a schematic diagram of the end cap of a battery cell according to some embodiments of this application. Figure 5 for Figure 4 The structure explodes. Figure 6 for Figure 4 Top view.

[0133] Please combine Figures 4 to 6 One embodiment of this application provides a battery cell 200, whose end cap 220 includes a cap body 221 and at least one functional component (not shown) mounted on the cap body 221. The cap body 221 has mounting holes corresponding to the functional components, and the functional components are mounted in the corresponding mounting holes. The cap body 221 has a buffer groove structure 201 corresponding to the functional components, and the buffer groove structure 201 surrounds the corresponding functional components.

[0134] Specifically, a functional component refers to a component mounted on the cover body 221 to perform certain functions within the battery cell 200. For example, a functional component is an electrode terminal, and the connection between the electrode terminal and the electrode terminal mounting hole is a weak point. Another example is a pressure relief mechanism, where the connection between the pressure relief mechanism 223 and the pressure relief mechanism mounting hole is a weak point.

[0135] Specifically, the cover body 221 may be equipped with one or more functional components. For example, the cover body 221 may be equipped with a pressure relief mechanism 223 without electrode terminals; or, the cover body 221 may be equipped with two electrode terminals without a pressure relief mechanism; or, the cover body 221 may be equipped with two electrode terminals and a pressure relief mechanism 223. At least one functional component is surrounded by a buffer groove structure 201. For example, a buffer groove structure 201 may be surrounded by a single electrode terminal; or, buffer groove structures 201 may be surrounded by two electrode terminals respectively. The pressure relief mechanism 223 may also be surrounded by a buffer groove structure 201.

[0136] The aforementioned battery cell 200 has mounting holes on its cover body 221 corresponding to functional components, which are then installed in these holes. The junction between the functional component and the corresponding mounting hole is a weak point. The cover body 221 also has a buffer groove structure 201 corresponding to the functional component. By providing the buffer groove structure 201, the strength of the area on the cover body 221 with the buffer groove structure 201 is reduced, while its toughness is increased, i.e., its deformation capacity is enhanced. Since the buffer groove structure 201 surrounds the corresponding functional component, it effectively forms a buffer zone around the functional component on the cover body 221. Thus, when the battery cell 200 is subjected to impact or undergoes cyclic expansion during charging and discharging, the buffer groove structure 201 can effectively disperse stress, reducing stress concentration at the junction of the functional component and the corresponding mounting hole, thereby reducing the risk of failure at the junction (i.e., the weak point).

[0137] To clearly illustrate the orientation, this application uses a first direction XX', a second direction YY', and a third direction ZZ' to describe the orientation. The third direction ZZ' represents the thickness direction of the cover body 221. The first direction XX', the second direction YY', and the third direction ZZ' intersect each other. Optionally, the first direction XX' represents the width direction of the cover body 221, and the second direction YY' represents the length direction of the cover body 221.

[0138] Please combine Figures 4 to 6 In one embodiment, at least one functional component is an electrode terminal, and the cover body 221 is provided with an electrode lead-out hole 202, which is the mounting hole corresponding to the electrode terminal.

[0139] The electrode terminal includes a terminal post 222 and a riveting member 224, with at least a portion of the terminal post 222 passing through the electrode lead-out hole 202. The riveting member 224 is located on the side of the cover body 221 facing outwards from the battery cell 200 along the thickness direction of the cover body 221. The riveting member 224 is connected to the terminal post 222 and is used to rivet the terminal post 222 to the cover body 221. The cover body 221 has a buffer groove structure 201a surrounding the electrode terminal.

[0140] exist Figures 4 to 6 In the illustrated embodiment, two electrode terminals (one positive electrode terminal and the other negative electrode terminal) are mounted on the cover body 221. Therefore, in this embodiment, the two functional components are electrode terminals, and the pole posts 222 of the two electrode terminals are respectively installed in their respective electrode lead-out holes 202. Moreover, the two electrode terminals are respectively surrounded by corresponding buffer groove structures 201a.

[0141] It is understandable that a buffer groove structure 201a may be provided around one of the electrode terminals, while no buffer groove structure may be provided around the other electrode.

[0142] Because a buffer groove structure 201a is provided around the electrode terminals, the buffer groove structure 201a forms a buffer band around the electrode terminals. When the battery cell 200 is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the sealing joint between the electrode post 222 and the hole wall of the electrode lead-out hole 202 can be reduced due to the deformation of the buffer band, thereby reducing the risk of sealing failure at the joint between the electrode post 222 and the electrode lead-out hole 202.

[0143] Figure 13 A top view of the end cap of a battery cell according to some embodiments of this application is shown. Figure 19 A top view of the end cap of a battery cell according to another embodiment of this application is shown. Figure 21 A top view of the end cap of a battery cell according to another embodiment of this application is shown. Figure 24 A top view of the end cap of a battery cell according to some other embodiments of this application is shown.

[0144] Please combine Figure 13 , Figure 19 , Figure 21 , Figure 24 In some embodiments, at least one functional component is a pressure relief mechanism 223, and the cover body 221 is provided with a pressure relief mechanism mounting hole 204, in which the pressure relief mechanism 223 is mounted. The cover body 221 is provided with a buffer groove structure 201b surrounding the pressure relief mechanism 223.

[0145] Because a buffer groove structure 201a is provided around the pressure relief mechanism 223, the buffer groove structure 201a forms a buffer zone around the pressure relief mechanism 223. When the battery cell 200 is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the joint between the pressure relief mechanism 223 and the pressure relief mechanism mounting hole 204 can reduce the stress concentration due to the deformation of the buffer zone, thereby reducing the risk of installation failure of the pressure relief mechanism 223.

[0146] In one embodiment, the buffer groove structure 201 is either a first type of buffer groove structure or a second type of buffer groove structure. The first type of buffer groove structure includes at least one circumferential buffer groove 2011, the circumferential buffer groove 2011 extending along the circumference of the functional component and surrounding the functional component. The second type of buffer groove structure includes multiple linear buffer grooves 2013, the multiple linear buffer grooves 2013 being distributed around the functional component, and at least some of the virtual extension lines of the linear buffer grooves 2013 forming an angle with the contour of the mounting hole.

[0147] Specifically, the first type of buffer groove structure may include one circumferential buffer groove 2011, or it may include multiple circumferential buffer grooves 2011. Each circumferential buffer groove 2011 is along the circumference of the corresponding functional component and surrounds the corresponding functional component.

[0148] The buffer groove structure 201a surrounding the electrode terminals can be either a first-type buffer groove structure or a second-type buffer groove structure. The buffer groove structure 201b surrounding the pressure relief mechanism 223 can be either a first-type buffer groove structure or a second-type buffer groove structure. Figures 4 to 6 In the embodiment shown, the buffer groove structure 201a surrounding the electrode terminal is a first type of buffer groove structure.

[0149] refer to Figures 4 to 6 In some embodiments, the first type of buffer groove structure includes multiple (e.g., two, three or more) circumferential buffer grooves 2011, which surround the structure from the inside out.

[0150] exist Figures 4 to 6 In the embodiment shown, two circumferential buffer grooves 2011 are provided around the electrode terminals, namely the first circumferential buffer groove 2011a and the second circumferential buffer groove 2011b.

[0151] Multiple circumferential buffer grooves 2011 surround the electrode terminals from the inside out, forming multiple buffer bands around the electrode terminals. When the battery cell 200 is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, these multiple buffer bands can distribute the force, further reducing the stress concentration at the sealing joint between the electrode post 222 and the electrode lead-out hole 202, and further reducing the risk of seal failure at the joint between the electrode post 222 and the electrode lead-out hole 202.

[0152] Figure 7 It shows Figure 6 A magnified view of a portion of point A in the middle. Figure 8 It shows Figure 6 A magnified view of a section at point B. Combined with... Figures 6 to 8 In some embodiments, each circumferential buffer groove 2011 is a continuous buffer groove, that is, a continuous circumferential buffer groove 2011. By making the circumferential buffer groove 2011 a continuous buffer groove, the buffering effect of the circumferential buffer groove 2011 can be improved.

[0153] Figure 12 A top view of the end cap of a battery cell according to other embodiments of this application is shown. Please refer to... Figure 12 Each circumferential buffer groove 2011 may also be a series of groove segments arranged circumferentially along the functional components, i.e., an intermittent circumferential buffer groove 2011.

[0154] In other embodiments, some of the circumferential buffer grooves 2011 may be continuous circumferential buffer grooves 2011, while some of the circumferential buffer grooves 2011 may be discontinuous circumferential buffer grooves 2011.

[0155] Combination Figures 6 to 8 In some embodiments, the first type of buffer groove structure further includes an additional buffer groove 2012, and the circumferential buffer groove 2011 is provided with at least one additional buffer groove 2012 on at least one side along the length direction of the cover body 221.

[0156] Specifically, in Figures 6 to 8 In the embodiment shown, for a single buffer groove structure 201a surrounding the electrode terminal, an additional buffer groove 2012 is provided on both sides of the circumferential buffer groove 2011 along the length direction of the cover body 221.

[0157] exist Figures 6 to 8 In the illustrated embodiment, by providing multiple circumferential buffer grooves 2011 that surround the cover body 221 from the inside out, these grooves fully occupy the space along the width direction of the cover body 221, but space still exists on both sides of the cover body 221 along its length. Providing additional buffer grooves 2012 in this space further enhances the deformation capability of the cover body 221 in the area surrounding the electrode terminals. This additional buffer grooves 2012 further disperse stress, significantly reducing stress concentration at the sealing joint between the electrode post 222 and the electrode lead-out hole 202, and further reducing the risk of seal failure at the joint between the electrode post 222 and the electrode lead-out hole 202.

[0158] In other embodiments, the circumferential buffer groove 2011 may have an additional buffer groove 2012 on only one side along the length of the cover body 221.

[0159] One additional buffer groove 2012 can be provided on any side of the circumferential buffer groove 2011 along the length of the cover body 221, or two, three or more additional buffer grooves 2012 can be provided.

[0160] Optionally, the extension direction of the additional buffer groove 2012 is along the width direction of the cover body 221.

[0161] In one embodiment, a circumferential buffer groove 2011 adjacent to the functional component is provided on the side of the cover body 221 facing outward from the battery cell 200 along the third direction ZZ'.

[0162] For example, please combine Figures 9 to 11 , Figure 9 It shows Figure 6 AA section view, Figure 10 It shows Figure 9 A magnified view of a section at point C. Figure 11 It shows Figure 10 A schematic diagram of the cover body. A circumferential buffer groove 2011 adjacent to the pole post 222 is the first circumferential buffer groove 2011a. The first circumferential buffer groove 2011a is located on the side of the cover body 221 facing outward from the battery cell 200 along the third direction ZZ'.

[0163] Because the force on the electrode post 222 is from the outside to the inside along the thickness direction of the cover body 221 under the bottom ball impact condition, the circumferential buffer groove 2011 adjacent to the electrode terminal is located on the side of the cover body 221 facing outward from the battery cell 200 along the third direction ZZ'. This makes the force direction on the electrode terminal the same as the groove depth direction of the circumferential buffer groove 2011, thereby achieving a better buffering and energy absorption effect.

[0164] Except for the circumferential buffer groove 2011 adjacent to the functional component, any number of other circumferential buffer grooves can be provided on the side of the cover body 221 facing the battery cell 200 along the third direction ZZ'.

[0165] Please combine Figure 13 , Figure 19 , Figure 21 In some embodiments, the buffer groove structure 201b surrounding the pressure relief mechanism 223 is a second type of buffer groove structure. (See reference...) Figure 14 Multiple linear buffer grooves 2013 are distributed around the pressure relief mechanism 223, and at least some of the virtual extension lines S of the linear buffer grooves 2013 form an angle α with the outline of the pressure relief mechanism mounting hole 204.

[0166] Please refer to the details. Figure 14 The virtual extension line S of the linear buffer groove 2013 is not a real outline, but rather refers to an extension line formed by assuming that the linear buffer groove 2013 continues to extend along its extension direction. The extension direction of the linear buffer groove 2013 can be defined by making the virtual extension line S of the linear buffer groove 2013 form an angle α with the outline of the pressure relief mechanism mounting hole 204.

[0167] exist Figure 14 In the process, the virtual extension line S of some linear buffer grooves 2013 forms an angle with the outline of the mounting hole. It can be understood that the virtual extension lines S of all linear buffer grooves 2013 can also form angles with the outline of the mounting hole.

[0168] The extension direction of the linear buffer groove 2013 can be along the length direction of the cover body 221, or along the width direction, or it can be inclined to the length and width directions of the cover body 221.

[0169] Please combine Figure 13 , Figure 19 , Figure 21 In some embodiments, the multiple linear buffer grooves 2013 are parallel to each other.

[0170] In other embodiments, there may be partially non-parallel linear buffer grooves 2013.

[0171] Please combine Figure 13 , Figure 19 , Figure 21 In some embodiments, the multiple linear buffer grooves 2013 are parallel to each other along the length or width direction of the cover body 221.

[0172] Regarding the case where the buffer groove structure 201b surrounding the pressure relief mechanism 223 is a type II buffer groove structure, if the width W of the cover body 221 is less than 60 mm, the cover body 221 will deform significantly along its length under bottom ball impact conditions, resulting in severe stress concentration. Therefore, in the buffer groove structure 201b surrounding the pressure relief mechanism 223, the linear buffer groove 2013 extends along the width direction of the cover body 221, such as... Figure 13 and Figure 19 As shown, multiple linear buffer grooves 2013 are parallel to each other along the width direction of the cover body 221; conversely, if the width W of the cover body 221 is greater than 60mm, the cover body 221 will deform significantly in the width direction under the impact of the bottom ball, resulting in severe stress concentration. Therefore, in the buffer groove structure 201b surrounding the pressure relief mechanism 223, the extension direction of the linear buffer grooves 2013 is along the length direction of the cover body 221, such as... Figure 21 As shown, multiple linear buffer grooves 2013 are parallel to each other along the length of the cover body 221.

[0173] It should be noted that the buffer groove structure surrounding the pressure relief mechanism 223 can also adopt the first type of buffer groove structure, such as the first type of buffer groove structure in any of the above embodiments.

[0174] The buffer groove structure surrounding the electrode terminals can also adopt a second type of buffer groove structure. Regarding the case where the buffer groove structure 201a surrounding the electrode terminals is a second type of buffer groove structure, if the width W of the cover body 221 is less than 50 mm, under the impact of a bottom ball, the cover body 221 deforms significantly in the length direction, resulting in severe stress concentration. Therefore, in the buffer groove structure 201a surrounding the electrode terminals, the extension direction of the linear buffer groove 2013 is along the width direction of the cover body 221, and multiple linear buffer grooves 2013 are parallel to each other along the width direction of the cover body 221. Conversely, if the width W of the cover body 221 is greater than 60 mm, under the impact of a bottom ball, the cover body 221 deforms significantly in the width direction, resulting in severe stress concentration. Therefore, in the buffer groove structure 201a surrounding the electrode terminals, the extension direction of the linear buffer groove 2013 is along the length direction of the cover body 221, and multiple linear buffer grooves 2013 are parallel to each other along the length direction of the cover body 221. If the width W of the cover body 221 is within the range of 45mm≤W≤60mm, the buffer groove structure surrounding the electrode terminal can be selected as the first type of buffer groove structure.

[0175] In some embodiments, the buffer groove structure 201 is divided into two parts, namely a first buffer groove and a second buffer groove. The first buffer groove is located on the side of the cover body 221 facing outward from the battery cell 200 along the third direction ZZ', and the second buffer groove is located on the side of the cover body 221 facing inward from the battery cell 200 along the third direction ZZ'.

[0176] exist Figures 9 to 10 In the embodiment shown, the buffer groove structure 201a surrounding the electrode terminal is divided into a first buffer groove and a second buffer groove. The first buffer groove includes a first circumferential buffer groove 2011a and a second circumferential buffer groove 2011b, and the second buffer groove includes a third circumferential buffer groove 2011c.

[0177] Figure 14 It shows Figure 13 A magnified view of a section at point D. Figure 15 It shows Figure 13 BB cross-section. Figure 16 It shows Figure 15 A magnified view of a section at point E in the middle. Figure 17 It shows Figure 15 A schematic diagram of the main body of the middle cover. Figure 18 It shows Figure 13 Bottom view of the middle end cap. Figures 13 to 18In the illustrated embodiment, the buffer groove structure 201b surrounding the pressure relief mechanism 223 is a second type of buffer groove structure, including multiple linear buffer grooves 2013 parallel to the width direction of the cover body 221. Specifically, the buffer groove structure 201b surrounding the pressure relief mechanism 223 is divided into a first part buffer groove and a second part buffer groove. The first part buffer groove includes multiple linear buffer grooves 2013 parallel to the width direction of the cover body 221, and the second part buffer groove includes multiple linear buffer grooves 2013 parallel to the width direction of the cover body 221.

[0178] Figure 22 It shows Figure 21 A magnified view of a section at point F. Figure 23 yes Figure 21 DD sectional view. In Figures 21 to 23 In the illustrated embodiment, the buffer groove structure 201b surrounding the pressure relief mechanism 223 is a second type of buffer groove structure, including multiple linear buffer grooves 2013 parallel to the length direction of the cover body 221. Specifically, the buffer groove structure 201b surrounding the pressure relief mechanism 223 is divided into a first part buffer groove and a second part buffer groove. The first part buffer groove includes multiple linear buffer grooves 2013 parallel to the length direction of the cover body 221; the second part buffer groove includes multiple linear buffer grooves 2013 parallel to the length direction of the cover body 221.

[0179] In this embodiment, the buffer groove structure 201 is divided into two parts located on both sides of the cover body 221, that is, a buffer band can be formed on both sides of the cover body 221. This can further enhance the deformation capacity of the cover body 221 in the area around the functional components, thereby further dispersing stress and further reducing the failure risk of weak parts.

[0180] In other embodiments, the buffer groove structure 201 surrounding the functional component may be provided only on the side of the cover body 221 facing outward from the battery cell 200 along the third direction ZZ', or the buffer groove structure 201 surrounding the functional component may be provided only on the side of the cover body 221 facing inward from the battery cell 200 along the third direction ZZ'.

[0181] Figure 24 A top view of the end cap of a battery cell according to some other embodiments of this application is shown. Figure 25 It shows Figure 24 Bottom view of the middle end cap. Figure 26 A top view of the end cap of a battery cell according to some other embodiments of this application is shown. Figure 27 It shows Figure 26 A magnified view of a section at point G. Figure 28 It shows Figure 26 EE sectional view.

[0182] Please combine Figure 24 and Figure 25 , Figures 26 to 28 In some embodiments, the plurality of linear buffer grooves 2013 include a plurality of first linear grooves 2013a and a plurality of second linear grooves 2013b. The plurality of first linear grooves 2013a are parallel to each other along a first direction XX', and the plurality of second linear grooves 2013b are parallel to each other along a second direction YY'.

[0183] Optionally, the first direction XX' is along the width direction of the cover body 221, and the second direction YY' is along the length direction of the cover body 221. It can be understood that the first direction XX' can also be inclined to the width direction of the cover body 221, and the second direction YY' can also be inclined to the width direction of the cover body 221.

[0184] exist Figure 24 and Figure 25 In the illustrated embodiment, multiple first linear grooves 2013a are provided on the side of the cover body 221 facing outwards from the battery cell 200 along the third direction ZZ', and multiple second linear grooves 2013b are provided on the side of the cover body 221 facing inwards from the battery cell 200 along the third direction ZZ'. In this embodiment, the first part of the buffer groove structure 201 is the multiple first linear grooves 2013a, and the second part of the buffer groove is the multiple second linear grooves 2013b.

[0185] exist Figures 26 to 28 In the illustrated embodiment, the cover body 221 has multiple first linear grooves 2013a and multiple second linear grooves 2013b on the side facing outward from the battery cell 200 along the third direction ZZ', and also has multiple first linear grooves 2013a and multiple second linear grooves 2013b on the side facing inward from the battery cell 200 along the third direction ZZ'. In this embodiment, the first part of the buffer groove structure 201 includes multiple first linear grooves 2013a and multiple second linear grooves 2013b, and the second part of the buffer groove structure 201 also includes multiple first linear grooves 2013a and multiple second linear grooves 2013b.

[0186] By setting multiple first linear grooves 2013a and multiple second linear grooves 2013b, with the extension direction of the first linear grooves 2013a along the first direction XX' and the extension direction of the second linear grooves 2013b along the second direction YY', the projections of the multiple first linear grooves 2013a and multiple second linear grooves 2013b form a grid, which can more effectively enhance the deformation capacity of the buffer groove structure and more effectively disperse stress, further reducing the failure risk of weak parts.

[0187] Please refer to Figure 8 and Figure 18In some embodiments, the cover body 221 is provided with a liquid injection hole 203. The buffer groove structure 201 has a break zone 203a on the side near the liquid injection hole 203, and the distance between the two ends of the break zone 203a is greater than or equal to the diameter of the liquid injection hole 203.

[0188] exist Figure 8 In the embodiment shown, the buffer groove structure 201a surrounding the electrode terminal has a second circumferential buffer groove 2011b on the side near the injection hole 203, and the second circumferential buffer groove 2011b has a break area 203a.

[0189] exist Figure 18 In the embodiment shown, the buffer groove structure 201b surrounding the pressure relief mechanism 223 consists of multiple linear buffer grooves 2013. Among the multiple linear buffer grooves 2013 located on the side of the cover body 221 facing the battery cell 200 along the third direction ZZ', one linear buffer groove 2013 near the injection hole 203 is provided with a break area 203a.

[0190] The buffer groove structure 201 has a break zone 203a on the side near the injection hole 203. The distance between the two ends of the break zone 203a is greater than or equal to the diameter of the injection hole 203, so that the buffer groove structure 201 and the injection hole 203 can maintain a distance as much as possible, thereby minimizing the weakening of strength near the injection hole 203.

[0191] In some embodiments, when the buffer groove structure 201 is divided into a first buffer groove and a second buffer groove, the projections of the first buffer groove and the second buffer groove along the thickness direction of the cover body 221 are completely offset or partially overlap.

[0192] Specifically, in Figures 9 to 11 In the embodiment shown, the projection of the third circumferential buffer groove 2011c along the thickness direction of the cover body 221 is located between the first circumferential buffer groove 2011a and the second circumferential buffer groove 2011b, that is, the projections of the first part of the buffer groove and the second part of the buffer groove along the thickness direction of the cover body 221 are completely offset.

[0193] exist Figures 13 to 18 In the embodiment shown, the projections of multiple linear buffer grooves 2013 on the cover body 221 along the third direction ZZ' towards the outside of the battery cell 200 and the projections of multiple linear buffer grooves 2013 on the cover body 221 along the third direction ZZ' towards the inside of the battery cell 200 along the thickness direction of the cover body 221 are alternately arranged, thereby ensuring that the projections of the multiple linear buffer grooves 2013 on the cover body 221 along the third direction ZZ' towards the outside of the battery cell 200 and the projections of the multiple linear buffer grooves 2013 on the cover body 221 along the third direction ZZ' towards the inside of the battery cell 200 along the thickness direction of the cover body 221 are completely staggered.

[0194] Similarly, in Figures 21 to 23 In the embodiment shown, the projections of the multiple linear buffer grooves 2013 of the cover body 221 toward the outside of the battery cell 200 along the third direction ZZ' are completely offset from the projections of the multiple linear buffer grooves 2013 of the cover body 221 toward the inside of the battery cell 200 along the thickness direction of the cover body 221.

[0195] By making the projections of the first part of the buffer groove and the second part of the buffer groove along the thickness direction of the cover body 221 completely offset or partially overlap, the overlapping area of ​​the first part of the buffer groove and the second part of the buffer groove on the cover body 221 can be minimized. The cover body 221 is weaker in the overlapping area, so the situation where the buffer groove structure 201 on the cover body 221 is weaker in a local area can be minimized.

[0196] In some other embodiments, the projections of the first buffer groove and the second buffer groove along the thickness direction of the cover body 221 may also partially overlap. For example, the projections of a portion of the linear buffer grooves 2013 in the first buffer groove and a portion of the linear buffer grooves 2013 in the second buffer groove along the thickness direction of the cover body 221 may overlap.

[0197] Please refer to Figure 11 and Figure 17 In some embodiments, the depth t1 of the first buffer groove satisfies the condition: 0.5t ≥ t1 ≥ 0.02t, and the depth t2 of the second buffer groove satisfies the condition: 0.5t ≥ t2 ≥ 0.02t, where t is the thickness of the cover body 221.

[0198] For example, when the depth t of the cover body 221 is in the range of 1.5mm≥t≥3.0mm, the depth t1 of the first buffer groove can be in the range of 0.3mm≥t1≥1mm, and the depth t2 of the second buffer groove can be in the range of 0.3mm≥t2≥1mm.

[0199] By setting 0.5t≥t1≥0.02t and 0.5t≥t2≥0.02t, the first and second buffer grooves can ensure that the cover body 221 has good deformation capacity and that the strength of the cover body 221 in the first and second buffer grooves is appropriate and not weakened too much.

[0200] In one embodiment, the depth of the buffer groove structure 201 varies as the distance to the functional component increases, and the depth decreases.

[0201] Understandably, the deeper the cover body 221 is in the buffer groove structure 201, the stronger its deformation capacity and the stronger its buffering capacity; conversely, the shallower the cover body 221 is in the buffer groove structure 201, the weaker its deformation capacity, but the higher its strength.

[0202] In this embodiment, the depth of the buffer groove structure 201 varies such that the greater the distance to the functional component, the shallower the depth; conversely, the closer the distance to the functional component, the deeper the depth. This allows the buffer groove structure 201 to have a stronger buffering capacity in the area closer to the functional component, effectively cushioning the area near the functional component and reducing the risk of failure at weak points. Simultaneously, because the buffer groove structure 201 becomes shallower as it gets farther from the functional component, it minimizes the weakening of the cover body 221's strength.

[0203] In other embodiments, the depth of the buffer groove structure 201 may also be uniform and constant, that is, the depth does not change due to the distance between the buffer groove structure 201 and the functional component.

[0204] Regarding the case where the buffer groove structure 201 is divided into a first buffer groove and a second buffer groove: The depth t1 of the first buffer groove can be uniform and constant; or, the depth t1 of the first buffer groove can vary according to the principle that t1 decreases as the distance to the functional component increases. The depth t2 of the second buffer groove can be uniform and constant; or, the depth t2 of the second buffer groove can vary according to the principle that t2 decreases as the distance to the functional component increases.

[0205] Figure 14 It shows Figure 13 A magnified view of a section at point D. Please refer to this image. Figure 7 , Figure 14 , Figure 21 , Figure 27 In some embodiments, the distance d1 from the buffer groove structure 201 to the edge of the cover body 221 satisfies the condition: d1 ≥ 0.8 mm. Optionally, 3.0 mm ≥ d1 ≥ 1.5 mm.

[0206] After the electrode assembly is installed in the housing, the end cap 220 is placed on the housing 210. The edge of the cap body 221 needs to be welded to the housing 210 to achieve fixation.

[0207] In this embodiment, by ensuring that the distance d1 between the buffer groove structure 201 and the edge of the cover body 221 meets the condition: d1≥0.8mm, the distance d1 between the buffer groove structure 201 and the edge of the cover body 221 can be appropriate, thereby ensuring the welding quality between the edge of the cover body 221 and the shell 210.

[0208] Figure 21 A top view of the end cap of a battery cell according to another embodiment of this application is shown. Please refer to... Figure 7 , Figure 14 , Figure 21 , Figure 27 In some embodiments, the distance between any two adjacent and parallel buffer slots is defined as d2. d2 can be uniform and constant. That is, the buffer slots are arranged at equal intervals.

[0209] The value range of d2 can be: 0.5W≥d2≥0.1W, where W refers to the width of the cover body 221.

[0210] In some other embodiments, d2 changes in the following way: the farther away from the functional component, the smaller d2 becomes. That is, the farther away from the functional component, the sparser the arrangement of the buffer grooves; conversely, the closer to the functional component, the denser the arrangement of the buffer grooves. This allows the buffer groove structure 201 to have a stronger buffering capacity in the area closer to the functional component, which is beneficial for providing a good buffering effect near the functional component and reducing the risk of failure of weak parts. At the same time, because the buffer grooves are arranged more sparsely with distance from the functional component, the weakening of the strength of the cover body 221 can be minimized.

[0211] In some embodiments, the cross-sectional shape of the buffer groove structure 201 is any one of a rectangle, trapezoid, triangle, or arc.

[0212] Specifically, the cross-sectional shape of the buffer groove structure 201 can be understood as the cross-sectional shape of any single buffer groove in the buffer groove structure 201. For example, for the first type of buffer groove structure, it can be the cross-sectional shape of the circumferential buffer groove; for the second type of buffer groove structure, it can be the cross-sectional shape of the first linear groove.

[0213] In one embodiment, the width w of the cross-section of the buffer groove structure 201 satisfies the condition: 10mm ≥ w ≥ 0.1mm. Optionally, 3mm ≥ w ≥ 0.5mm.

[0214] For the buffer groove structure 201, which is divided into a first buffer groove and a second buffer groove, please refer to... Figure 11 , Figure 17 The width w1 of the cross-section of the first buffer groove satisfies the condition: 10mm ≥ w1 ≥ 0.1mm; optionally, 3mm ≥ w1 ≥ 0.5mm. The width w2 of the cross-section of the second buffer groove satisfies the condition: 10mm ≥ w1 ≥ 0.1mm; optionally, 3mm ≥ w2 ≥ 0.5mm.

[0215] The width of the cross-section of the buffer groove structure 201 should be understood as the dimension at the position of the maximum width of the cross-sectional shape; for example, for a triangular cross-section, it should refer to the dimension of the base of the triangle, and for a trapezoidal cross-section, it should refer to the dimension of the larger base of the trapezoid.

[0216] Please combine Figure 5 , Figure 9 as well as Figure 10 In one embodiment, the battery cell 200 further includes an insulating member 225, which is disposed between the riveting member 224 and the cover body 221 along the thickness direction of the cover body 221.

[0217] Along a direction perpendicular to the thickness of the cover body 221, the distance L from the buffer groove structure 201a surrounding the electrode terminal to the insulating member 225 is greater than 1 mm. Optionally, 3 mm ≥ L ≥ 1.5 mm.

[0218] for Figure 5 , Figure 9 as well as Figure 10 In the illustrated embodiment, the buffer groove structure 201a surrounding the electrode terminals is divided into a first buffer groove (including a first circumferential buffer groove 2011a and a second circumferential buffer groove 2011b) and a second buffer groove (including a third circumferential buffer groove 2011c). Along a direction perpendicular to the thickness direction of the cover body 221, the distance L1 from the first buffer groove to the insulating member 225 is greater than 1 mm, and the distance L2 from the second buffer groove to the insulating member 225 is greater than 1 mm. Optionally, 3 mm ≥ L1 ≥ 1.5 mm, and 3 mm ≥ L2 ≥ 1.5 mm.

[0219] In this embodiment, by ensuring that the distance L from the buffer groove structure 201a surrounding the electrode terminal to the insulating member 225 is greater than 1 mm along a direction perpendicular to the thickness direction of the cover body 221, a suitable distance can be maintained between the buffer groove structure 201a and the insulating member 225. This allows the buffer groove structure 201 to effectively disperse stress around the electrode terminal while ensuring that the buffer groove structure 201a does not affect the assembly of the insulating member 225 and the cover body 221.

[0220] Please combine Figures 13 to 18 In one embodiment, a protective patch 2231 is also installed within the pressure relief mechanism mounting hole 204, and the pressure relief mechanism 223 is located on the side of the protective patch 2231 near the interior of the battery cell 200. Along a direction perpendicular to the thickness direction of the cover body 221, the portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 located on the side of the cover body 221 facing the battery cell 200 along a third direction ZZ' is at a distance N greater than 1 mm from the pressure relief mechanism 223. Optionally, 3 mm ≥ N ≥ 1.5 mm.

[0221] Specifically, the protective patch 2231 is disposed on the side of the pressure relief mechanism 223 along the third direction ZZ' towards the outside of the battery cell 200, serving to protect the pressure relief mechanism 223. Therefore, since the pressure relief mechanism 223 is relatively close to the side of the cover body 221 along the third direction ZZ' towards the inside of the battery cell 200, it is necessary to ensure that the portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 located on the side of the cover body 221 along the third direction ZZ' towards the inside of the battery cell 200 has sufficient distance from the pressure relief mechanism 223 to reduce the impact on the assembly of the pressure relief mechanism 223 and to reduce the problem of poor sealing at the pressure relief mechanism 223.

[0222] exist Figures 13 to 18 In the illustrated embodiment, the buffer groove structure 201b surrounding the pressure relief mechanism 223 is divided into a first buffer groove and a second buffer groove. The buffer groove structure 201b surrounding the pressure relief mechanism 223 is located on the side of the cover body 221 facing the battery cell 200 along the third direction ZZ', i.e., the second buffer groove. Please refer to... Figure 18 That is, the distance N from the second buffer tank to the pressure relief mechanism 223 is greater than 1mm.

[0223] For the case where the buffer groove structure 201b surrounding the pressure relief mechanism 223 is entirely located on the side of the cover body 221 facing the battery cell 200 along the third direction ZZ', that is, the distance N from the buffer groove structure 201b surrounding the pressure relief mechanism 223 to the pressure relief mechanism 223 is greater than 1mm.

[0224] In this embodiment, the portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 along the direction perpendicular to the thickness of the cover body 221, located on the side of the cover body 221 facing the battery cell 200 along the third direction ZZ', is at a distance N greater than 1mm from the pressure relief mechanism 223. This ensures that the portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 located on the side of the cover body 221 facing the battery cell 200 along the third direction ZZ' has sufficient distance from the pressure relief mechanism 223, thereby reducing the impact on the assembly of the pressure relief mechanism 223 and reducing the problem of poor sealing at the pressure relief mechanism 223.

[0225] Figure 20 It shows Figure 19 The CC section view. Please refer to... Figures 19 to 20 In some embodiments, the cover body 221 is provided with a boss 226 protruding outward along the third direction ZZ', and the boss 226 is arranged around the circumferential edge of the pressure relief mechanism mounting hole 204.

[0226] The portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 located on the side of the cover body 221 facing outward from the battery cell 200 along the third direction ZZ' is located on the periphery of the boss 226.

[0227] Specifically, the boss 226 can form a retaining structure on the circumferential edge of the pressure relief mechanism mounting hole 204, thereby preventing electrolyte from entering the pressure relief mechanism mounting hole 204 when injecting liquid into the injection hole.

[0228] The portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 located on the side of the cover body 221 facing outwards from the battery cell 200 along the third direction ZZ' can be the first portion of the buffer groove; or, the entire buffer groove structure 201b surrounding the pressure relief mechanism 223 may be located on the side of the cover body 221 facing outwards from the battery cell 200 along the third direction ZZ', that is, the portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 located on the side of the cover body 221 facing outwards from the battery cell 200 along the third direction ZZ' is the entire buffer groove structure 201b.

[0229] By positioning the portion of the buffer groove structure 201b surrounding the pressure relief mechanism 223 on the side of the cover body 221 facing outwards from the battery cell 200 along the third direction ZZ', and placing it outside the boss 226, and offset from the boss 226, the buffer groove structure 201b will not extend into the boss 226, thus keeping the boss 226 intact and effectively providing a containment function.

[0230] This application also provides a battery device 10, including a battery box 100 and a battery cell 200 of any of the above embodiments, wherein the battery cell 200 is located inside the battery box 100.

[0231] The battery cell 200 of the aforementioned battery device 10 has mounting holes on its cover body 221 corresponding to functional components, which are then installed in these holes. The junction between the functional component and the corresponding mounting hole is a weak point. The cover body 221 also has a buffer groove structure 201 corresponding to the functional component. By providing the buffer groove structure 201, the strength of the area on the cover body 221 with the buffer groove structure 201 is reduced, while its toughness is increased, i.e., its deformation capacity is enhanced. Since the buffer groove structure 201 surrounds the corresponding functional component, it effectively forms a buffer zone around the functional component on the cover body 221. Thus, when the battery cell 200 is subjected to impact or undergoes cyclic expansion during charging and discharging, the buffer groove structure 201 can effectively disperse stress, reducing stress concentration at the junction of the functional component and the corresponding mounting hole, thereby reducing the risk of failure at the junction (i.e., the weak point).

[0232] This application embodiment also provides an electrical device, including a battery device 10, which is used to provide electrical energy to the electrical device.

[0233] In the aforementioned electrical device, the cover body 221 is provided with mounting holes corresponding to functional components, which are then installed in these holes. The junction between the functional component and the corresponding mounting hole is a weak point. The cover body 221 is provided with a buffer groove structure 201 corresponding to the functional component. By providing the buffer groove structure 201, the strength of the area of ​​the cover body 221 with the buffer groove structure 201 is weakened, while its toughness is enhanced, i.e., its deformation capacity is increased. Since the buffer groove structure 201 surrounds the corresponding functional component, it surrounds the junction between the functional component and the corresponding mounting hole, thus the buffer groove structure 201 is equivalent to a buffer zone formed around the functional component on the cover body 221. In this way, when the battery cell 200 is subjected to impact conditions or undergoes cyclic expansion during charging and discharging, the buffer groove structure 201 can effectively disperse stress, reduce the stress concentration at the junction between the functional component and the corresponding mounting hole, and thereby reduce the risk of failure at the junction (i.e., the weak point) between the functional component and the corresponding mounting hole.

[0234] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery cell, characterized in that, The battery cell includes an end cap, the end cap includes a cap body and at least one functional component, the cap body is provided with a mounting hole corresponding to the functional component, and the functional component is mounted in the corresponding mounting hole; The cover body is provided with a buffer groove structure corresponding to the functional component, and the buffer groove structure surrounds the corresponding functional component; The buffer groove structure is either a first type of buffer groove structure or a second type of buffer groove structure; The first type of buffer groove structure includes at least one circumferential buffer groove, the circumferential buffer groove extending along the circumference of the functional component and surrounding the functional component; The second type of buffer groove structure includes multiple linear buffer grooves, which are distributed around the functional component, and at least some of the virtual extension lines of the linear buffer grooves form an angle with the outline of the mounting hole; At least one of the functional components is a pressure relief mechanism, and the cover body is provided with a pressure relief mechanism mounting hole, and the pressure relief mechanism is installed in the pressure relief mechanism mounting hole; The cover body is provided with a buffer groove structure surrounding the pressure relief mechanism. The buffer groove structure surrounding the pressure relief mechanism is either the first type of buffer groove structure or the second type of buffer groove structure. A protective patch is also installed inside the mounting hole of the pressure relief mechanism, and the pressure relief mechanism is located on the side of the protective patch close to the inside of the battery cell along the thickness direction of the cover body; Along a direction perpendicular to the thickness direction of the cover body, the portion of the buffer groove structure surrounding the pressure relief mechanism located on the side of the cover body facing the battery cell along the thickness direction of the cover body is more than 1 mm away from the pressure relief mechanism.

2. The battery cell according to claim 1, characterized in that, The multiple linear buffer grooves are parallel to each other.

3. The battery cell according to claim 2, characterized in that, The multiple linear buffer grooves are parallel to each other along the length or width of the cover body.

4. The battery cell according to claim 1, characterized in that, The first type of buffer groove structure includes multiple circumferential buffer grooves, which surround each other from the inside out.

5. The battery cell according to claim 1, characterized in that, The circumferential buffer groove is a continuous buffer groove; or, the circumferential buffer groove includes multiple groove segments arranged at circumferential intervals along the functional component.

6. The battery cell according to claim 1, characterized in that, The first type of buffer groove structure also includes an additional buffer groove, and the circumferential buffer groove is provided with at least one additional buffer groove on at least one side along the length direction of the cover body.

7. The battery cell according to claim 1, characterized in that, The plurality of linear buffer grooves include a plurality of first linear grooves and a plurality of second linear grooves. The plurality of first linear grooves are parallel to each other along a first direction, and the plurality of second linear grooves are parallel to each other along a second direction. The first direction and the second direction intersect.

8. The battery cell according to claim 1, characterized in that, The circumferential buffer groove adjacent to the functional component is located on the side of the cover body facing outward from the battery cell along a third direction, where the third direction is the thickness direction of the cover body.

9. The battery cell according to claim 1, characterized in that, The cover body is provided with a liquid injection hole; The buffer tank structure has a break zone on the side near the injection hole, and the distance between the two ends of the break zone is greater than or equal to the diameter of the injection hole.

10. The battery cell according to claim 1, characterized in that, The buffer groove structure is located on the side of the cover body facing outwards from the battery cell in a third direction; or, The buffer groove structure is located on the side of the cover body facing inwards towards the battery cell in a third direction; or... The buffer groove structure is divided into a first buffer groove and a second buffer groove. The first buffer groove is located on the side of the cover body facing outward from the battery cell in a third direction, and the second buffer groove is located on the side of the cover body facing inward from the battery cell in a third direction. Wherein, the third direction is the thickness direction of the cover body.

11. The battery cell according to claim 10, characterized in that, The projections of the first part of the buffer groove and the second part of the buffer groove along the thickness direction of the cover body are completely offset or partially overlap.

12. The battery cell according to claim 10, characterized in that, The depth t1 of the first buffer groove satisfies the condition: 0.5t ≥ t1 ≥ 0.02t, and the depth t2 of the second buffer groove satisfies the condition: 0.5t ≥ t2 ≥ 0.02t, where t is the thickness of the cover body; The range of t is: 1.5mm≥t≥3mm; the range of t1 is: 0.3mm≥t1≥1mm; the range of t2 is: 0.3mm≥t2≥1mm.

13. The battery cell according to claim 10, characterized in that, The depth of the buffer groove structure is uniform and constant; or, the depth of the buffer groove structure varies according to the distance to the functional component, the depth is smaller.

14. The battery cell according to claim 13, characterized in that, The buffer groove structure is divided into a first buffer groove and a second buffer groove. The first buffer groove is located on the side of the cover body facing outward from the battery cell along the third direction, and the second buffer groove is located on the side of the cover body facing inward from the battery cell along the third direction. The depth of the first buffer groove t1 is uniform and constant; or, the depth t1 of the first buffer groove varies in that the farther away from the functional component, the smaller t1 becomes. The depth t2 of the second buffer groove is uniform and constant; or, the depth t2 of the second buffer groove varies according to the distance to the functional component, the smaller t2 is.

15. The battery cell according to claim 1, characterized in that, Define the distance between any two adjacent and parallel buffer slots as d2; The variation pattern of d2 is as follows: the farther the distance to the functional component, the smaller d2 becomes; or, d2 is uniform and constant.

16. The battery cell according to claim 1, characterized in that, The distance d1 from the buffer groove structure to the edge of the cover body satisfies the condition: d1≥0.8mm.

17. The battery cell according to any one of claims 1-16, characterized in that, At least one of the functional components is an electrode terminal; the cover body is provided with an electrode lead-out hole, and the mounting hole corresponding to the electrode terminal is the electrode lead-out hole; The electrode terminal includes a post and a rivet. At least a portion of the post passes through the electrode lead-out hole. The rivet is located on the side of the cover body facing outward from the battery cell along the thickness direction of the cover body. The rivet is connected to the post and is used to rivet the post to the cover body. The cover body is provided with a buffer groove structure surrounding the electrode terminal, and the buffer groove structure surrounding the electrode terminal is either the first type of buffer groove structure or the second type of buffer groove structure.

18. The battery cell according to claim 17, characterized in that, The battery cell also includes an insulating component, which is disposed between the riveting component and the cover body along the thickness direction of the cover body; Along a direction perpendicular to the thickness direction of the cover body, the distance from the buffer groove structure surrounding the electrode terminal to the insulating member is greater than 1 mm.

19. The battery cell according to claim 1, characterized in that, The cover body is provided with a boss that protrudes outward along the thickness direction of the cover body, and the boss is arranged around the circumferential edge of the pressure relief mechanism mounting hole. The portion of the buffer groove structure surrounding the pressure relief mechanism located on the side of the cover body facing outwards from the battery cell along the thickness direction of the cover body is located around the boss.

20. A battery device, characterized in that, It includes a battery box and a battery cell according to any one of claims 1-19, wherein the battery cell is located inside the battery box.

21. An electrical appliance, characterized in that, The battery device of claim 20 is included, wherein the battery device is used to provide electrical energy to the electrical device.

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