A battery cell, current collector, battery device, and electric device

Abstract

The application discloses a battery monomer, a current collector, a battery device and an electric equipment. The battery monomer comprises an electrode assembly, an end cover and a current collector. The electrode assembly comprises a tab. The end cover comprises an electrode terminal. The current collector is arranged between the end cover and the electrode assembly. The current collector comprises a first connecting part, a second connecting part and a buffer part. The first connecting part is connected with the tab. The second connecting part is connected with the electrode terminal. The buffer part is located between the first connecting part and the second connecting part. The buffer part is provided with a groove. The buffer part is elastically deformed through the groove, and is used for absorbing external impact. The technical scheme provided by the embodiment of the application can improve the toughness of the current collector and reduce the risk of fracture failure.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a battery cell, current collector, battery device, and electrical equipment. Background Technology

[0002] A battery cell includes a current collector, a tab, and electrode terminals. The current collector is connected between the tab and the electrode terminals. Due to the vibration and impact in the environment where the battery cell is used, the current collector is prone to breakage and failure. Utility Model Content

[0003] To address the aforementioned technical problems, the purpose of this application is to provide a battery cell, a current collector, a battery device, and an electrical appliance.

[0004] The first aspect of this application provides a battery cell, including an electrode assembly, an end cap, and a current collector. The electrode assembly includes tabs; the end cap includes electrode terminals; the current collector is disposed between the end cap and the electrode assembly, and includes a first connecting portion, a second connecting portion, and a buffer portion. The first connecting portion is connected to the tabs, and the second connecting portion is connected to the electrode terminals; the buffer portion is located between the first connecting portion and the second connecting portion, and the buffer portion has a groove. The buffer portion absorbs external impacts through elastic deformation of the groove. In the technical solution provided by the embodiments of this application, the electrode assembly is used to store and provide electrical energy, and the electrical energy is transmitted through the tabs. The end cap is used to seal the ends of the electrode assembly, and the electrode terminals enable electrical connection between the tabs and external electrical equipment. The current collector is disposed between the end cap and the electrode assembly, with the first connecting portion of the current collector connected to the tabs and the second connecting portion of the current collector connected to the electrode terminals, thereby electrically connecting the tabs and the electrode terminals. Based on this, the current collector also includes a buffer section disposed between the first connecting part and the second connecting part. The buffer section has a groove, which allows for elastic deformation. The groove provides deformation space, and the more complex structure of the buffer section with the groove helps to disperse the impact force and guide the buffer section to undergo elastic deformation, thereby absorbing the impact force and improving the toughness of the current collector. This effectively reduces the impact of the impact force on the current collector, thus protecting it and reducing the possibility of it breaking due to external vibration. Compared with related technologies where current collectors are prone to breakage due to external vibration, the current collector in this embodiment is provided with a buffer section, and the buffer section has a groove, which helps the buffer section to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector, and reducing the risk of breakage failure.

[0005] In some embodiments of this application, the first connecting part and the second connecting part are arranged sequentially along the first direction, the groove extends along the second direction, and the second direction is set at an angle to the first direction.

[0006] Here, external impact vibration is transmitted between the first connecting part and the second connecting part, that is, along the layout direction of the first connecting part and the second connecting part (first direction). The extension direction of the trough (second direction) is set at an angle with the first direction, which makes it easier for the buffer part to use the trough to undergo elastic deformation, which helps to improve the energy absorption effect of the buffer part.

[0007] In some embodiments of this application, the trough has a preset profile perpendicular to its extension direction, and the size of the preset profile is uniformly set along the extension direction of the trough.

[0008] Here, the preset contour dimensions of the tank are uniformly set, the structure of the tank is relatively simple, and the processing is more convenient; moreover, the structure of the tank is smoother, reducing stress concentration, so as to improve the structural strength of the current collector.

[0009] In some embodiments of this application, the projection of the groove body along its extension direction is arc-shaped or polygonal.

[0010] Here, the contour of the trough is arc-shaped, and the surface transition is smoother, which can effectively disperse the force and reduce stress concentration, making it suitable for scenarios with large impacts; the contour of the trough is polygonal, and the buffer part corresponds to each part of the trough relatively independently, which can quickly respond to deformation to absorb energy, making it suitable for scenarios with frequent vibrations.

[0011] In some embodiments of this application, the current collector is a plate-shaped structure with a first dimension along the thickness direction, and the maximum dimension of the tank along the thickness direction of the current collector is a second dimension. The ratio of the second dimension to the first dimension is greater than or equal to 1 / 5 and less than or equal to 1 / 3.

[0012] Here, the depth dimension (second dimension) of the tank and the thickness dimension (first dimension) of the current collector are set within a reasonable range, which not only facilitates the energy absorption of the buffer part through elastic deformation, but also reduces the adverse effect of the tank on the structural strength of the buffer part, and makes it easier for the buffer part to maintain appropriate structural strength.

[0013] In some embodiments of this application, at least one end of the groove extends through the buffer portion along the extension direction of the groove.

[0014] Here, the through-buffered groove is easier to process, and the through-buffered groove has a larger extension dimension, which can cover different edges of the buffer and enhance the promoting effect of a single groove on elastic deformation.

[0015] In some embodiments of this application, at least two tanks are provided on the same side of the current collector, and the at least two tanks are spaced apart.

[0016] Here, setting multiple grooves on the same side of the current collector makes it easier for the buffer part to deform elastically, which helps to improve the toughness of the current collector; the spacing of multiple grooves makes it easier to cover a larger area and can reduce the adverse effects on the structural strength of the buffer part caused by the excessive size of a single groove.

[0017] In some embodiments of this application, at least two grooves are arranged in parallel directions, and at least two grooves are arranged sequentially in a perpendicular direction.

[0018] Here, the parallel arrangement of the tank structure makes manufacturing easier, and the spacing between the parallel tanks is more uniform, so that the buffer part is evenly stressed, reducing stress concentration and helping to improve the energy absorption and buffering effect.

[0019] In some embodiments of this application, at least two grooves extend in the same direction, and at least two grooves are arranged sequentially along the extension direction.

[0020] Here, at least two troughs are arranged sequentially along the extension direction, which makes it easier to reduce the size of a single trough and helps to arrange more troughs at the buffer section, thereby improving the energy absorption and buffering effect of the buffer section.

[0021] In some embodiments of this application, at least two grooves are arranged at an angle to each other in their extension directions.

[0022] Here, the extension direction of the trough is set at an angle to accommodate irregularly shaped buffer sections. The distance between adjacent troughs is smaller where the buffer section is smaller, and larger where the buffer section is larger.

[0023] In some embodiments of this application, the distance between two adjacent grooves is greater than or equal to 1 mm and less than or equal to 5 mm.

[0024] Here, the extension direction of the trough is set at an angle to accommodate irregularly shaped buffer sections. The distance between adjacent troughs is smaller where the buffer section is smaller, and larger where the buffer section is larger.

[0025] In some embodiments of this application, the current collector includes a first side facing the end cap and a second side facing the electrode assembly; at least one of the first side and the second side is provided with a groove.

[0026] Here, a groove is provided on the first side of the current collector, which helps the current collector to elastically deform toward the end cap, and is suitable for situations where the distance between the current collector and the end cap is large; a groove is provided on the second side of the current collector, which helps the current collector to elastically deform toward the electrode assembly, and is suitable for situations where the distance between the current collector and the electrode assembly is large; grooves are provided on both the first and second sides, and the elastic deformation direction of the current collector is relatively free, which helps to improve the energy absorption and buffering effect.

[0027] In some embodiments of this application, at least two troughs are provided on the first side and the second side respectively, and the troughs on the first side and the troughs on the second side are arranged alternately along the extension direction of the current collector.

[0028] Here, along the extension direction of the current collector, the grooves on different sides of the current collector are alternately distributed, and the elastic deformation direction of the buffer part is different corresponding to the grooves on different sides. The alternating distribution of grooves on different sides helps to generate a greater degree of elastic deformation, thereby improving the energy absorption and buffering effect.

[0029] In some embodiments of this application, at least two grooves are provided on the first side and the second side respectively. Two adjacent grooves on the first side have a first distance, and two adjacent grooves on the second side have a second distance. The first distance is not equal to the second distance.

[0030] Here, the first spacing between adjacent tanks on the first side is not equal to the second spacing between adjacent tanks on the second side, so that the structures of the first and second sides of the current collector are different, thereby facilitating elastic deformation and improving the energy absorption effect.

[0031] In some embodiments of this application, the current collector includes two first connecting portions, which are symmetrically arranged about a second connecting portion, and a buffer portion is provided between the second connecting portion and each of the first connecting portions.

[0032] Here, a buffer section is provided between the two first connecting parts and the second connecting parts of the current collector. The corresponding buffer section can provide energy absorption buffer for the connection parts of different first connecting parts and second connecting parts.

[0033] A second aspect of this application provides a current collector disposed between the electrode assembly and the end cap of a battery cell. The current collector includes a first connecting portion, a second connecting portion, and a buffer portion. The first connecting portion is connected to the tab of the electrode assembly, and the second connecting portion is connected to the electrode terminal of the end cap. The buffer portion is located between the first connecting portion and the second connecting portion, and the buffer portion has a groove forming a deformation space for the buffer portion.

[0034] In the technical solution of this application embodiment, a buffer part is provided between the first connecting part and the second connecting part of the current collector, and the buffer part has a groove, which helps the buffer part to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector, and reducing the risk of fracture failure.

[0035] A third aspect of this application provides a battery device including a battery cell of any one of the first aspects.

[0036] In the technical solution of this application embodiment, the battery device includes the battery cell in this application embodiment. The current collector of the battery cell is provided with a buffer part between the first connection part and the second connection part, and the buffer part has a groove, which helps the buffer part to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector, and reducing the risk of breakage failure.

[0037] A fourth aspect of this application provides an electrical device including a battery cell of any one of the first aspects, or a battery device of the third aspect.

[0038] In the technical solution of this application embodiment, the electrical equipment includes the battery cell in this application embodiment. The current collector of the battery cell is provided with a buffer part between the first connection part and the second connection part, and the buffer part is provided with a groove, which helps the buffer part to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector, and reducing the risk of fracture failure. Attached Figure Description

[0039] 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:

[0040] Figure 1 This is a schematic diagram of the structure of the electrical device provided in the embodiments of this application;

[0041] Figure 2 This is a schematic diagram of the structure of a single battery cell provided in an embodiment of this application;

[0042] Figure 3 This is a schematic diagram of the exploded structure of a single battery cell provided in an embodiment of this application;

[0043] Figure 4 This is a schematic diagram of the current collector structure in a battery cell provided in an embodiment of this application;

[0044] Figure 5 Provided for the embodiments of this application Figure 4 A schematic diagram of the cross-sectional structure along the middle AA line;

[0045] Figure 6 This is a schematic diagram of the pre-defined contour in a battery cell provided in the embodiments of this application;

[0046] Figure 7 This is a schematic diagram of the structure of the battery cell with the grooves spaced along the extension direction, provided in an embodiment of this application.

[0047] Figure 8 This is a schematic diagram of the structure of a battery cell in which adjacent cells form an angle, provided in an embodiment of this application.

[0048] Figure 9 This is a schematic diagram of a groove structure provided on the first side of the current collector in a battery cell according to an embodiment of this application;

[0049] Figure 10 A schematic diagram of a groove structure provided on the second side of the current collector in a battery cell according to an embodiment of this application;

[0050] Figure 11 Provided for the embodiments of this application Figure 10 Schematic diagram of the cross-sectional structure along the middle edge BB;

[0051] Figure 12 This is a schematic diagram of a battery cell with grooves on both sides of the current collector, provided in an embodiment of this application.

[0052] Figure 13 Provided for the embodiments of this application Figure 12 A schematic diagram of the cross-sectional structure along the CC line;

[0053] Figure 14 This is a schematic diagram of the alternating distribution of grooves on both sides of the current collector in a battery cell provided in an embodiment of this application.

[0054] Explanation of reference numerals in the attached figures:

[0055] 100 - Electrode assembly; 110 - Tab; 200 - End cap; 210 - Electrode terminal; 300 - Current collector; 310 - First connection part; 320 - Second connection part; 330 - Buffer part; 340 - Tank; 350 - First side; 360 - Second side; 400 - Housing; 500 - Equipment body; X - First direction; Y - Second direction; H1 - First dimension; H2 - Second dimension; D - Spacing; D1 - First spacing; D2 - Second spacing. Detailed Implementation

[0056] 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.

[0057] 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 belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit this application; the terms “comprising” and “having”, and any variations thereof, in the specification and the foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0058] In the description of the embodiments of this application, technical terms such as "first," "second," and "third" 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.

[0059] 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.

[0060] 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 are in an "or" relationship.

[0061] In the description of the embodiments of this application, the technical terms "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., 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 do not indicate or imply that the device or element referred to must have a specific orientation, be constructed, operated or used in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0062] 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.

[0063] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical term "contact" should be interpreted broadly, and can be direct contact, contact through an intermediate medium layer, contact between two contacting parties with substantially no interaction force, or contact between two contacting parties with interaction force.

[0064] The following is a detailed description of this application:

[0065] Batteries are increasingly used in daily life and industry. They are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also widely used in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in aerospace and other fields. As the application areas of batteries continue to expand, the market demand for them is also constantly increasing.

[0066] Vehicles and other electrical equipment experience vibrations and shocks during operation. For example, when a vehicle travels on bumpy roads or experiences emergency braking or collisions, these vibrations and shocks are transmitted to the battery cells. The current collector connecting the tabs and electrode terminals in the battery cell is prone to breakage due to impact. Some technical solutions reduce the impact on the current collector by increasing the contact area between the plastic under the end cap and the tabs, and by increasing the compression of the separator in the electrode assembly. However, this can lead to insufficient space for tab misalignment, and narrowing of the tabs can cause the battery cell to overheat, affecting its lifespan. Furthermore, excessive compression can cause the upper and lower electrode sheets to fold and wrinkle, posing a risk of internal short circuits within the battery cell. Therefore, it is difficult to solve the problem of the current collector being prone to breakage due to impact.

[0067] This application addresses the problems existing in the aforementioned related technologies by proposing a battery cell. An electrode assembly stores and provides electrical energy, which is transmitted through tabs. An end cap seals the ends of the electrode assembly and provides electrical connection between the tabs and external electrical devices via electrode terminals. A current collector is disposed on the end cap and the electrode assembly. A first connecting portion of the current collector connects to the tabs, and a second connecting portion connects to the electrode terminals, thus electrically connecting the tabs and electrode terminals. Furthermore, the current collector includes a buffer portion disposed between the first and second connecting portions. The buffer portion has a groove, allowing for elastic deformation. The groove provides deformation space, and the more complex structure of the buffer portion with the groove helps to disperse the impact force and guide the elastic deformation of the buffer portion, thereby absorbing the impact force and improving the toughness of the current collector. This effectively reduces the impact of impact forces on the current collector, protecting it and reducing the possibility of breakage due to external vibration.

[0068] Reference Figure 1 This application provides an electrical device, including a device body 500, the device body being provided with a battery cell (including an end cap 200) or a battery device (including a battery cell).

[0069] In some implementations, the electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0070] In some embodiments, the electrical device is an electric vehicle, and the device body 500 may include a drive motor, control components, vehicle air conditioning, vehicle entertainment system, etc. in the electric vehicle. The battery cell or battery device is located on the underside of the vehicle body and provides electrical energy to the device body 500.

[0071] Reference Figure 2 , Figure 3 and Figure 4 The battery cell provided in this application embodiment includes an electrode assembly 100, an end cap 200, and a current collector 300. The electrode assembly 100 includes a tab 110; the end cap 200 includes an electrode terminal 210; the current collector 300 is disposed between the end cap 200 and the electrode assembly 100, and the current collector 300 includes a first connecting portion 310, a second connecting portion 320, and a buffer portion 330. The first connecting portion 310 is connected to the tab 110, and the second connecting portion 320 is connected to the electrode terminal 210; the buffer portion 330 is located between the first connecting portion 310 and the second connecting portion 320, and the buffer portion 330 has a groove 340. The buffer portion 330 elastically deforms through the groove 340 to absorb external impacts.

[0072] In some embodiments, the electrode assembly 100 includes a positive electrode, a negative electrode, and a separator disposed between the negative electrode and the positive electrode. During the charging and discharging process of a single battery cell, active ions (e.g., lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, disposed between the positive and negative electrodes, serves to prevent short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0073] In some embodiments, the electrode assembly 100 can be cylindrical, flat, or polygonal in shape; the electrode assembly 100 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked. One or more positive and negative electrode plates can be provided, with multiple positive and multiple negative electrode plates alternately stacked. The electrode assembly 100 is provided with tabs 110, which can conduct current from the electrode assembly 100. The tabs 110 include positive tabs 110 and negative tabs 110.

[0074] In some embodiments, the battery cell may include a casing. The casing may be a steel casing, an aluminum casing, a plastic casing (such as a polypropylene casing), a composite metal casing (such as a copper-aluminum composite casing), or an aluminum-plastic film, etc.

[0075] In some embodiments, the housing can be a sealed structure or a non-sealed structure. As an example, when the housing is a non-sealed structure, it serves to protect the electrode assembly 100, and a sealing bag is included between the housing and the electrode assembly 100. The sealing bag is used to encapsulate the electrode assembly 100 and the electrolyte. Specifically, the sealing bag can be a bag-shaped insulating component or an aluminum-plastic film. When the housing is a sealed structure, it is used to encapsulate the electrode assembly 100 and other components such as the electrolyte.

[0076] In some embodiments, the housing includes an end cap 200 and a housing 400, the housing 400 having a receiving cavity and an opening, the electrode assembly 100 and the current collector 300 being housed in the receiving cavity, the end cap 200 covering the opening, the end cap 200 including an electrode terminal 210, the electrode terminal 210 being connected to a tab 110 via a corresponding current collector 300.

[0077] In some embodiments, the battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic batteries, such as hexagonal prismatic batteries. This application does not have any particular limitations.

[0078] In some embodiments, the current collector 300 can be a block structure, a rod structure, a plate structure, etc. For example, the current collector 300 is a plate structure, and the first connecting part 310, the buffer part 330 and the second connecting part 320 are arranged along the extension direction of the current collector 300. The current collector 300 can be an integrally formed component, or it can be fixed by welding, bonding or other methods of multiple components.

[0079] In some embodiments, the first connecting portion 310 of the current collector 300 is connected to the tab 110, and the connection between the two can be welding, bonding, etc. For example, the first connecting portion 310 and the tab 110 are ultrasonically welded; the second connecting portion 320 of the current collector 300 is connected to the electrode terminal 210, and the connection between the two can be welding, bonding, etc. For example, the second connecting portion 320 and the electrode terminal 210 are laser welded.

[0080] In some embodiments, the groove 340 refers to a spatial structure in which an opening is provided on one side surface of the component, while no opening is provided on the opposite side surface, and the opening extends along the surface.

[0081] In some embodiments, the tank 340 includes a bottom wall disposed opposite to the opening, and two side walls connected between the bottom wall and the opening, the two side walls being disposed opposite to each other. Both the bottom wall and the side walls can be planar or curved surfaces. In some examples, both the bottom wall and the side walls of the tank 340 are planar; in other examples, both the bottom wall and the side walls of the tank 340 are curved surfaces with the same curvature.

[0082] In the technical solution provided in this application embodiment, the electrode assembly 100 is used to store and provide electrical energy. The electrical energy is transmitted through the tab 110. The end cap 200 is used to seal the end of the electrode assembly 100 and realizes the electrical connection between the tab 110 and the external electrical equipment through the electrode terminal 210. The current collector 300 is disposed on the end cap 200 and the electrode assembly 100. The first connecting part 310 of the current collector 300 is connected to the tab 110, and the second connecting part 320 of the current collector 300 is connected to the electrode terminal 210, thereby electrically connecting the tab 110 and the electrode terminal 210.

[0083] Based on this, the current collector 300 also includes a buffer section 330, which is disposed between the first connecting section 310 and the second connecting section 320. The buffer section 330 has a groove 340, which can achieve elastic deformation. The groove 340 provides deformation space, and the structure of the buffer section 330 with the groove 340 is more complex, which helps to disperse the impact force and guide the buffer section 330 to undergo elastic deformation, thereby absorbing the impact force. The toughness of the current collector 300 is improved, which can effectively reduce the impact force on the current collector 300, thereby protecting the current collector 300 and reducing the possibility of the current collector 300 breaking due to external vibration.

[0084] Compared with related technologies, where the current collector 300 is prone to breakage due to external vibration, the current collector 300 in this embodiment is provided with a buffer part 330, and the buffer part 330 has a groove 340, which helps the buffer part 330 to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector 300, and reducing the risk of breakage failure.

[0085] To improve the energy absorption effect of the buffer section 330, refer to Figure 4 In some embodiments of this application, the first connecting portion 310 and the second connecting portion 320 are arranged sequentially along the first direction X, and the groove 340 extends along the second direction Y, with the second direction Y forming an angle with the first direction X.

[0086] In some embodiments, the first direction X is the direction of the line connecting any point of the first connecting portion 310 and any point of the second connecting portion 320; for example, the first direction X is the direction of the line connecting the center of the first connecting portion 310 and the center of the second connecting portion 320.

[0087] In some examples, the extension direction of the groove 340 refers to the direction of the longest side of its opening. For example, if the opening of the groove 340 is rectangular, the extension direction of the groove 340 is the length direction of the opening. It should be noted that the extension direction of the groove 340 can be a straight line, a curve, or a broken line.

[0088] In some embodiments, the current collector 300 is provided with a plurality of first connecting portions 310 for connecting different tabs 110. A buffer portion 330 is provided between the second connecting portion 320 and each connecting portion. It is understood that the first direction X is different for different first connecting portions 310, and the second direction Y is set at an angle to the corresponding first direction X.

[0089] In the technical solution provided in this application embodiment, external impact vibration is transmitted between the first connecting part 310 and the second connecting part 320, that is, transmitted along the arrangement direction (first direction X) of the first connecting part 310 and the second connecting part 320. The extension direction (second direction Y) of the groove body 340 is set at an angle with the first direction X, so that the buffer part 330 can use the groove body 340 to perform elastic deformation, which helps to improve the energy absorption effect of the buffer part 330.

[0090] For ease of processing, refer to Figure 4 and Figure 5 In some embodiments of this application, the groove 340 has a preset profile perpendicular to its extension direction, and the size of the preset profile is uniformly set along the extension direction of the groove 340.

[0091] In some examples, the preset profile is the cross-sectional profile of the channel 340, or the preset profile is the profile of the channel 340 projected orthographically along the extension direction. The dimensions of the preset profile are uniformly set along the extension direction of the channel 340, meaning that if a cross-section is taken at any two points along the extension direction of the channel 340, the preset profiles of the two cross-sections have the same structure and dimensions.

[0092] In other embodiments, the preset contours at different locations along the extension direction of the groove 340 may be different. For example, the size of the preset contour gradually increases or decreases along the extension direction of the groove 340; or, for example, the groove 340 includes multiple segments along the extension direction of the groove 340, the preset contour size of the same segment is the same, the preset contour size of different segments is different, and the preset contour of the groove 340 is stepped.

[0093] In the technical solution provided in this application embodiment, the preset contour size of the tank 340 is uniformly set, the structure of the tank 340 is relatively simple, and the processing is more convenient; and the structure of the tank 340 is smoother, reducing stress concentration, so as to improve the structural strength of the current collector 300.

[0094] To adapt to different impact scenarios, refer to Figure 5 and Figure 6 In some embodiments of this application, the projection outline of the groove 340 is arc-shaped or polygonal, projected along the extension direction of the groove 340.

[0095] In some examples, the projected profile along the extension direction of the groove 340 is a preset profile. The projected profile of the groove 340 along the extension direction can be an arc, which can be a major arc, a minor arc, etc. In some examples, the orthographic projection profile of the groove 340 along the extension direction is a semicircular arc.

[0096] In other examples, the orthographic projection profile of the trough 340 along the extension direction is a polygon. The polygon can be a square, rectangle, trapezoid, hexagon, etc. For example, the orthographic projection profile of the trough 340 along the extension direction is a rectangle, where two opposite sides correspond to the sidewalls of the trough 340, and the other two sides correspond to the opening and bottom wall of the trough 340, respectively.

[0097] In the technical solution provided in this application embodiment, the outline of the trough 340 is arc-shaped, and the surface transition is smoother, which can effectively disperse the force and reduce stress concentration, making it suitable for scenarios with large impacts; the outline of the trough 340 is polygonal, and the buffer part 330 corresponds to each part of the trough 340 relatively independently, which can quickly respond to deformation to absorb energy, making it suitable for scenarios with frequent vibrations.

[0098] To balance energy absorption and structural strength, refer to Figure 5 and Figure 6 In some embodiments of this application, the current collector 300 is a plate-shaped structure, the current collector 300 has a first dimension H1 along the thickness direction, the maximum dimension of the tank 340 along the thickness direction of the current collector 300 is a second dimension H2, and the ratio of the second dimension H2 to the first dimension H1 is greater than or equal to 1 / 5 and less than or equal to 1 / 3.

[0099] In some examples, the plate-like structure has a current collector 300 whose dimensions in two of the three mutually perpendicular directions are much larger than its dimensions in the other direction. Here, "much larger" can be understood as the ratio of the larger dimension to the smaller dimension being greater than or equal to 5. The direction containing the smaller dimension of the current collector 300 is its thickness direction, and the current collector 300 has a first dimension H1 along its thickness direction.

[0100] In some examples, the maximum dimension of the tank 340 along the thickness direction of the current collector 300 can be understood as the depth dimension of the tank 340. The depth dimension of the tank 340 refers to the maximum dimension between the bottom wall of the tank 340 and the plane containing the opening. The depth dimension of the tank 340 is the second dimension H2. It can be understood that the second dimension H2 of the tank 340 is not greater than the first dimension H1 of the current collector 300.

[0101] In some examples, the second dimension H2 of the tank 340 is set to be larger, and the first dimension H1 of the buffer part 330 corresponding to the position of the tank 340 is smaller. The buffer part 330 is more prone to elastic deformation, which is beneficial to improving the energy absorption effect of the buffer part 330. The second dimension H2 of the tank 340 is set to be smaller, and the first dimension H1 of the buffer part 330 corresponding to the position of the tank 340 is larger. The buffer part 330 can provide a higher connection strength between the first connecting part 310 and the second connecting part 320.

[0102] In this case, the ratio of the second dimension H2 to the first dimension H1 is greater than or equal to 1 / 5 and less than or equal to 1 / 3. In some examples, the ratio of the second dimension H2 to the first dimension H1 is greater than or equal to 1 / 5 and less than or equal to 1 / 4, such as 1 / 5, 2 / 9, 1 / 4, etc. In other examples, the ratio of the second dimension H2 to the first dimension H1 is greater than or equal to 1 / 4 and less than or equal to 1 / 3, such as 1 / 4, 2 / 7, 3 / 10, 1 / 3, etc.

[0103] In the technical solution provided in this application embodiment, the depth dimension (second dimension H2) of the tank 340 and the thickness dimension (first dimension H1) of the current collector 300 are set within a reasonable range, which not only facilitates the buffer part 330 to absorb energy through elastic deformation, but also reduces the adverse effect of the tank 340 on the structural strength of the buffer part 330, and makes it easier for the buffer part 330 to maintain a suitable structural strength.

[0104] To enhance the promoting effect of the groove 340 on elastic deformation, refer to Figure 3 and Figure 4 In some embodiments of this application, at least one end of the groove 340 extends through the buffer portion 330 along the extending direction of the groove 340.

[0105] In some examples, at least one end of the trough 340 extends through the buffer portion 330 along its extension direction. This means that the end of the trough 340 along its extension direction is also provided with a notch, the surface of which is adjacent to the surface of the opening of the trough 340, and the notch is provided between the opening and the bottom wall of the trough 340. It can be understood that the notch at the end of the trough 340 is located on the wall surface of the buffer portion 330 parallel to the first direction X.

[0106] In some examples, one end of the groove 340 extends through the buffer portion 330 along its extension direction. This end of the groove 340 extending through the buffer portion 330 may be located inside the buffer portion 330, where "inner side" refers to the side of the buffer portion 330 located between the two first connecting portions 310. Alternatively, the end of the groove 340 extending through the buffer portion 330 may be located outside the buffer portion 330, where "outer side" refers to the opposite side from the inner side. In other examples, both ends of the groove 340 extend through the buffer portion 330 along its extension direction.

[0107] In the technical solution provided in this application embodiment, the groove 340 that penetrates the buffer portion 330 is easier to process, and the extension direction dimension of the groove 340 that penetrates is large, which can cover different edges of the buffer and enhance the promoting effect of a single groove 340 on elastic deformation.

[0108] To facilitate the elastic deformation of the buffer section 330, refer to Figure 7 , Figure 8 and Figure 9 In some embodiments of this application, at least two tanks 340 are provided on the same side of the current collector 300, and the at least two tanks 340 are spaced apart.

[0109] In some examples, one or more (including two) slots 340 may be provided on the same side of the current collector 300. For example, four or more slots 340 may be provided on the side of the current collector 300 near the end cap 200; or, for another example, four or more slots 340 may be provided on the side of the current collector 300 near the electrode assembly 100.

[0110] In some examples, multiple channels 340 on the same side of the current collector 300 adopt the same preset profile. For example, the preset profiles of the multiple channels 340 are all square, or the multiple channels 340 include at least two different preset profiles. In addition, the channels 340 on the same side of the current collector 300 may have the same or different dimensions.

[0111] In some examples, the spacing between at least two slots 340 can be either in the first direction X or in the second direction Y. In some examples, adjacent slots 340 are spaced apart in the first direction X; in other examples, adjacent slots 340 are spaced apart in the second direction Y.

[0112] In some examples, the spacing D between two adjacent slots 340 can be uniform, or the spacing D between two adjacent slots 340 can gradually increase or decrease. Furthermore, the spacing between any two slots 340 can be the same or different. In some examples, the spacing D between multiple adjacent slots 340 is uniform.

[0113] In the technical solution provided in this application embodiment, setting multiple grooves 340 on the same side of the current collector 300 makes it easier for the buffer part 330 to undergo elastic deformation, which helps to improve the toughness of the current collector 300; the spacing of multiple grooves 340 makes it easier to cover a larger area, and can reduce the adverse effects on the structural strength of the buffer part 330 caused by the excessive size of a single groove 340.

[0114] To improve the energy absorption and buffering effect, refer to Figure 4In some embodiments of this application, at least two grooves 340 are arranged in parallel directions, and at least two grooves 340 are arranged sequentially in the perpendicular direction of extension.

[0115] In some examples, the current collector 300 has two or more grooves 340 on the side facing the end cap 200, and the extension directions of the grooves 340 are parallel. In other examples, the current collector 300 has two or more grooves 340 on the side facing the electrode assembly 100, and the extension directions of the grooves 340 are parallel. The spacing D between any two adjacent grooves 340 can be the same or different; in some examples, the spacing D between any two adjacent grooves 340 is equal.

[0116] In some examples, multiple grooves 340 on the same side of the current collector 300 have the same extending direction, and the arrangement direction of the multiple grooves 340 is perpendicular to the extending direction. For example, the multiple grooves 340 are arranged along the first direction X, and the extending direction of each groove 340 is perpendicular to the first direction X.

[0117] In the technical solution provided in this application embodiment, the parallel arrangement of the groove 340 structure is more convenient to manufacture, and the spacing D of the parallel arrangement of the groove 340 is more uniform, so that the buffer part 330 is evenly stressed, reducing stress concentration and helping to improve the energy absorption and buffering effect.

[0118] To improve the energy absorption and buffering effect, refer to Figure 7 In some embodiments of this application, at least two grooves 340 extend in the same direction, and at least two grooves 340 are arranged sequentially along the extension direction.

[0119] In some examples, the current collector 300 has two or more grooves 340 on the side facing the end cap 200, and at least two grooves 340 have the same extending direction, that is, at least two grooves 340 are provided in the same extending direction; in some examples, the current collector 300 has two or more grooves 340 on the side facing the electrode assembly 100, and at least two grooves 340 have the same extending direction, that is, at least two grooves 340 are provided in the same extending direction.

[0120] In some examples, multiple tanks 340 on the same side of the current collector 300 can be divided into multiple tank groups, each tank group including at least two tanks 340; multiple tanks 340 in the same tank group are arranged in the same extending direction, and multiple tank groups are arranged at intervals, for example, multiple tank groups are arranged at intervals along the first direction X.

[0121] In the technical solution provided in this application embodiment, at least two grooves 340 are arranged sequentially along the extension direction, which makes it easier to reduce the size of a single groove 340 and helps to arrange more grooves 340 at the position of the buffer part 330, thereby improving the energy absorption and buffering effect of the buffer part 330.

[0122] To accommodate buffer sections 330 of different shapes, refer to Figure 8 In some embodiments of this application, at least two grooves 340 extend at an angle to each other.

[0123] In some examples, the current collector 300 has two or more grooves 340 on the side facing the end cap 200, and the extending directions of at least two grooves 340 are at an angle, which can be an obtuse angle, an acute angle, or a right angle; in other examples, the current collector 300 has two or more grooves 340 on the side facing the electrode assembly 100, and the extending directions of at least two grooves 340 are at an angle, which can be an obtuse angle, an acute angle, or a right angle.

[0124] In some examples, a portion of the channel 340 on the same side of the current collector 300 has two adjacent channels 340, and the included angle between the channel 340 and the two adjacent channels 340 can be the same; or, the channel 340 has different included angles with the two adjacent channels 340, for example, the extending axis of the channel 340 can serve as the axis of symmetry of the two adjacent channels 340.

[0125] In the technical solution provided in this application embodiment, the extension direction of the groove 340 is set at an angle to accommodate the irregularly shaped buffer part 330. The distance D between the buffer part 330 and the groove 340 is smaller at the smaller position and larger at the larger position.

[0126] To balance energy absorption and structural strength, refer to Figure 5 and Figure 6 In some embodiments of this application, the distance D between two adjacent grooves 340 is greater than or equal to 1 mm and less than or equal to 5 mm.

[0127] In some examples, the extension directions of two adjacent grooves 340 are parallel, and the distance D between the two grooves 340 is uniform, which is greater than or equal to 1 mm and less than or equal to 5 mm; in other examples, the extension directions of two adjacent grooves 340 are at an angle, and the distance D between the two grooves 340 gradually increases or gradually decreases, with the minimum distance D being greater than or equal to 1 mm and the maximum distance D being less than or equal to 5 mm.

[0128] In some examples, the spacing D between two adjacent grooves 340 is set to be small, allowing for more grooves 340 to be provided on the buffer portion 330 per unit area. This facilitates the elastic deformation of the buffer portion 330 and helps improve its energy absorption and buffering effect. Conversely, a larger spacing D between two adjacent grooves 340 results in a larger proportion of the buffer portion 330 without grooves 340, which helps provide a higher connection strength between the buffer portion 330 and the first connecting portion 310 and the second connecting portion 320.

[0129] In some examples, the distance D between two adjacent tanks 340 is greater than or equal to 1 mm and less than or equal to 5 mm. In other examples, the distance D between two adjacent tanks 340 is greater than or equal to 1 mm and less than or equal to 3 mm, such as 1.0 mm, 1.5 mm, 2.0 mm, 2.5 mm, 3.0 mm, etc. In other examples, the distance D between two adjacent tanks 340 is greater than or equal to 3 mm and less than or equal to 5 mm, such as 3.0 mm, 3.5 mm, 4.0 mm, 4.5 mm, 5.0 mm, etc.

[0130] In the technical solution provided in this application embodiment, the distance D between the two grooves 340 is set within a reasonable range, which not only helps to arrange a reasonable number of grooves 340 on the buffer part 330 to improve the energy absorption and buffering effect, but also keeps the buffer part 330 at a reasonable structural strength to reduce the risk of breakage of the current collector 300.

[0131] To facilitate the elastic deformation of the buffer section 330, refer to Figure 5 , Figure 11 , Figure 12 and Figure 13 In some embodiments of this application, the current collector 300 includes a first side 350 facing the end cap 200 and a second side 360 ​​facing the electrode assembly 100; at least one of the first side 350 and the second side 360 ​​is provided with a groove 340.

[0132] In some examples, the current collector 300 is provided with one or more grooves 340 on the first side 350 facing the end cap 200; in other examples, the current collector 300 is provided with one or more grooves 340 on the second side 360 ​​facing the electrode assembly 100.

[0133] In some other examples, the first side 350 of the current collector 300 is provided with one or more grooves 340, and the second side 360 ​​of the current collector 300 is also provided with one or more grooves 340. The number of grooves 340 on the first side 350 and the number of grooves 340 on the second side 360 ​​may be the same or different. For example, the first side 350 and the second side 360 ​​have the same number of grooves 340, such as two, three, four, etc. The embodiments of this application do not limit this.

[0134] In some examples, multiple grooves 340 on different sides of the current collector 300 adopt the same preset profile. For example, the grooves 340 on both sides of the current collector 300 are both set to a square preset profile, or the grooves 340 on both sides of the current collector 300 include at least two different preset profiles. In addition, the grooves 340 on different sides of the current collector 300 may have the same or different dimensions.

[0135] In some examples, when projected along the thickness direction of the current collector 300, the projection of the first side 350 groove 340 and the projection of the second side 360 ​​groove 340 at least partially overlap. Then, the ratio of the sum of the dimensions of the first side 350 groove 340 and the second side 360 ​​groove 340 to the first dimension H1 is greater than or equal to 1 / 5 and less than or equal to 1 / 3, such as 1 / 5, 2 / 9, 1 / 4, 2 / 7, 3 / 10, 1 / 3, etc., so as to keep the minimum thickness dimension of the buffer part 330 within a reasonable range and reduce the impact of the superposition of the second dimension H2 of the grooves 340 on both sides of the current collector 300 on the structural strength of the buffer part 330.

[0136] In other examples, when projected along the thickness direction of the current collector 300, the projections of the first side 350 groove 340 and the second side 360 ​​groove 340 do not overlap. In this case, the ratio of the second dimension H2 of the groove 340 on different sides of the current collector 300 to the first dimension H1 is greater than or equal to 1 / 5 and less than or equal to 1 / 3, such as 1 / 5, 2 / 9, 1 / 4, 2 / 7, 3 / 10, 1 / 3, etc.

[0137] In the technical solution provided in this application embodiment, a groove is provided on the first side 350 of the current collector 300, which helps the current collector 300 to elastically deform toward the end cap 200, and is suitable for situations where the distance D between the current collector 300 and the end cap 200 is large; a groove is provided on the second side 360 ​​of the current collector 300, which helps the current collector 300 to elastically deform toward the electrode assembly 100, and is suitable for situations where the distance D between the current collector 300 and the electrode assembly 100 is large; both the first side 350 and the second side 360 ​​are provided with grooves 340, and the elastic deformation direction of the current collector 300 is relatively free, which helps to improve the energy absorption and buffering effect.

[0138] To improve the energy absorption and buffering effect, refer to Figure 14 In some embodiments of this application, at least two grooves 340 are provided on the first side 350 and the second side 360 ​​respectively. Along the extension direction of the current collector 300, the grooves 340 on the first side 350 and the grooves 340 on the second side 360 ​​are arranged alternately.

[0139] In some examples, the extension direction of the current collector 300 refers to any direction in the plane perpendicular to the thickness direction of the current collector 300. The extension direction of the current collector 300 can be a first direction X, a second direction Y, or other directions perpendicular to the thickness direction of the current collector 300.

[0140] In some examples, when projected along the thickness direction of the current collector 300, the projections of the first side 350 groove 340 and the second side 360 ​​groove 340 do not overlap, and there is at least one projection of the second side 360 ​​groove 340 between two adjacent projections of the first side 350 groove 340, or there is at least one projection of the second side 360 ​​groove 340 between two adjacent projections of the second side 360 ​​groove 340.

[0141] In some examples, when projecting along the thickness direction of the current collector 300, there is a projection of a second side 360 ​​groove 340 between two adjacent projections of the first side 350 groove 340, and there is a projection of a second side 360 ​​groove 340 between two adjacent projections of the second side 360 ​​groove 340, that is, the projections of the first side 350 groove 340 and the projections of the second side 360 ​​groove 340 are alternately arranged in the extension direction of the current collector 300.

[0142] In the technical solution provided in this application embodiment, along the extension direction of the current collector 300, the grooves 340 located on different sides of the current collector 300 are alternately distributed, and the elastic deformation direction of the buffer part 330 corresponding to the grooves 340 on different sides is different. The alternating distribution of the grooves 340 on different sides helps to generate a greater degree of elastic deformation, thereby improving the energy absorption and buffering effect.

[0143] To improve energy absorption, refer to Figure 12 and Figure 13 In some embodiments of this application, at least two slots 340 are respectively provided on the first side 350 and the second side 360. Two adjacent slots 340 on the first side 350 have a first distance D1, and two adjacent slots 340 on the second side 360 ​​have a second distance D2. The first distance D1 is not equal to the second distance D2.

[0144] In some examples, the first side 350 of the current collector 300 is provided with two or more grooves 340, and the first spacing D1 between two adjacent grooves 340 is uniformly provided. The second side 360 ​​of the current collector 300 is provided with two or more grooves 340, and the second spacing D2 between two adjacent grooves 340 is uniformly provided.

[0145] In some examples, the first spacing D1 is greater than the second spacing D2; in other examples, the first spacing D1 is less than the second spacing D2; in yet another example, the first spacing D1 and the second spacing D2, the trough 340 located on the first side 350 and the trough 340 located on the second side 360 ​​are alternately arranged along the extension direction of the current collector 300.

[0146] In the technical solution provided in this application embodiment, the first spacing D1 of the adjacent grooves 340 on the first side 350 is not equal to the second spacing D2 of the adjacent grooves 340 on the second side 360, so that the structures of the first side 350 and the second side 360 ​​of the current collector 300 are different, thereby facilitating elastic deformation and improving the energy absorption effect.

[0147] To improve the energy absorption and buffering effect, refer to Figure 3 and Figure 4 In some embodiments of this application, the current collector 300 includes two first connecting portions 310, which are symmetrically arranged about a second connecting portion 320, and a buffer portion 330 is provided between the second connecting portion 320 and each of the first connecting portions 310.

[0148] In some embodiments, the buffer section 330 is the weakest structural area on the current collector 300. The buffer section 330 is not connected to other components, and the first connecting portion 310 and the second connecting portion 320 at both ends of the buffer section 330 are respectively connected to different components.

[0149] In some examples, the first dimension H1 of the portion of the buffer section 330 without the groove 340 is equal to the first dimension H1 of the first connecting portion 310 or the second connecting portion; in other examples, the first dimension H1 of the portion of the buffer section 330 without the groove 340 is greater than the first dimension H1 of the first connecting portion 310 or the second connecting portion; and in still other examples, the first dimension H1 of the portion of the buffer section 330 without the groove 340 is less than the first dimension H1 of the first connecting portion 310 or the second connecting portion.

[0150] In the technical solution provided in the embodiments of this application, a buffer portion 330 is provided between the two first connecting portions 310 and the second connecting portion 320 of the current collector 300. The corresponding buffer portion 330 can provide energy absorption buffer for the connection parts of different first connecting portions 310 and second connecting portions 320.

[0151] This application embodiment also provides a current collector 300, which is disposed between the electrode assembly 100 and the end cap 200 of a battery cell. The current collector 300 includes a first connecting part 310, a second connecting part 320 and a buffer part 330. The first connecting part 310 is connected to the tab 110 of the electrode assembly 100, and the second connecting part 320 is connected to the electrode terminal 210 of the end cap 200. The buffer part 330 is located between the first connecting part 310 and the second connecting part 320, and the buffer part 330 has a groove 340, which forms a deformation space for the buffer part 330.

[0152] In the technical solution of this application embodiment, the current collector 300 is provided with a buffer part 330 between the first connecting part 310 and the second connecting part 320, and the buffer part 330 is provided with a groove 340, which helps the buffer part 330 to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector 300, and reducing the risk of fracture failure.

[0153] This application also provides a battery device, including the battery cell of this application embodiment.

[0154] In some embodiments, the electrical device includes at least one battery module, which includes multiple stacked battery cells that are electrically connected in series, parallel, or mixed connection. Alternatively, the electrical device includes a battery casing containing multiple stacked battery cells that are electrically connected in series, parallel, or mixed connection.

[0155] In some implementations, the battery device can provide power to vehicles, drones, etc.; in other implementations, the battery device can be an energy storage device, such as a battery swapping station or an uninterruptible power supply.

[0156] In the technical solution of this application embodiment, the battery device includes the battery cell in this application embodiment. The current collector 300 of the battery cell is provided with a buffer portion 330 between the first connecting portion 310 and the second connecting portion 320, and the buffer portion 330 is provided with a groove 340, which helps the buffer portion 330 to elastically deform, thereby absorbing the impact force of external vibration, improving the toughness of the current collector 300, and reducing the risk of breakage failure.

[0157] In one possible embodiment of this application, the electrical device is an electric vehicle, which includes a power battery for providing electrical energy for the electric vehicle's operation. The electrical device includes multiple stacked battery cells, each battery cell including a housing 400 and an end cap 200. The housing 400 has a receiving cavity and an opening. The receiving cavity houses an electrode assembly 100. The electrode assembly 100 has two positive electrode tabs 110 and two negative electrode tabs 110 on one side corresponding to the opening. The end cap 200 covers the opening to close the receiving cavity. The battery cell includes a positive electrode terminal 210 and a negative electrode terminal 210. It also includes two current collectors 300. Each current collector 300 includes two first connecting parts 310 and one second connecting part 320. In one current collector 300, the two first connecting parts 310 are ultrasonically welded to two positive electrode tabs 110, and the second connecting part 320 is laser-welded to the positive electrode terminal 210. In the other current collector 300, the two first connecting parts 310 are ultrasonically welded to two negative electrode tabs 110, and the second connecting part 320 is laser-welded to the negative electrode terminal 210. Two current collectors 300 adopt the same structure and are symmetrically arranged about the end cap 200. Taking one of the current collectors 300 as an example, a buffer portion 330 is provided between each first connecting part 310 and second connecting part 320, corresponding to the first side 350 and / or the second side 360 ​​of the current collector 300. Multiple grooves 340 are formed on the corresponding side of the buffer portion 330. The grooves 340 on different sides are alternately distributed along the extension direction of the buffer portion 330. The ratio of the second dimension H2 of the groove 340 to the first dimension H1 of the current collector 300 is greater than or equal to 1 / 5 and less than or equal to 1 / 3. The spacing D of the grooves 340 on the same side is greater than or equal to 1 mm and less than or equal to 5 mm. The extension directions of the multiple grooves 340 on the same side are parallel, and the extension direction of the grooves 340 is perpendicular to the corresponding first direction X.

[0158] The above embodiments are merely illustrative of the technical solutions of this application and are not intended to limit it. 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 all should be covered within the scope of this application's specification. 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 application documents.

Claims

1. A battery cell, characterized in that, include: Electrode assembly, including tabs; End caps, including electrode terminals; A current collector is disposed between the end cap and the electrode assembly. The current collector includes a first connecting part, a second connecting part, and a buffer part. The first connecting part is connected to the electrode tab, and the second connecting part is connected to the electrode terminal. The buffer part is located between the first connecting part and the second connecting part. The buffer part has a groove. The buffer part absorbs external impacts through elastic deformation of the groove.

2. The battery cell according to claim 1, characterized in that, The first connecting part and the second connecting part are arranged sequentially along the first direction, and the groove extends along the second direction, which is set at an angle to the first direction.

3. The battery cell according to claim 1, characterized in that, The groove has a preset contour perpendicular to its extension direction, and the dimensions of the preset contour are uniformly set along the extension direction of the groove.

4. The battery cell according to claim 3, characterized in that, The projection of the groove body along its extension direction is either arc-shaped or polygonal.

5. The battery cell according to claim 1, characterized in that, The current collector has a plate-like structure and a first dimension along its thickness direction. The maximum dimension of the trough along the thickness direction of the current collector is a second dimension. The ratio of the second dimension to the first dimension is greater than or equal to 1 / 5 and less than or equal to 1 / 3.

6. The battery cell according to claim 1, characterized in that, Along the extending direction of the groove, at least one end of the groove passes through the buffer portion.

7. The battery cell according to any one of claims 1 to 6, characterized in that, At least two tanks are provided on the same side of the current collector, and the at least two tanks are spaced apart.

8. The battery cell according to claim 7, characterized in that, At least two of the grooves are arranged in parallel directions, and at least two of the grooves are arranged in sequence perpendicular to the direction of extension.

9. The battery cell according to claim 7, characterized in that, At least two of the tanks extend in the same direction, and at least two of the tanks are arranged sequentially along the extension direction.

10. The battery cell according to claim 7, characterized in that, At least two of the grooves extend at an angle to each other.

11. The battery cell according to claim 7, characterized in that, The distance between two adjacent grooves is greater than or equal to 1 mm and less than or equal to 5 mm.

12. The battery cell according to any one of claims 1 to 6, characterized in that, The current collector includes a first side facing the end cap and a second side facing the electrode assembly; At least one of the first side and the second side is provided with the groove.

13. The battery cell according to claim 12, characterized in that, At least two of the aforementioned grooves are provided on the first side and the second side respectively, and the grooves on the first side and the grooves on the second side are arranged alternately along the extension direction of the current collector.

14. The battery cell according to claim 12, characterized in that, At least two grooves are provided on the first side and the second side respectively. Two adjacent grooves on the first side have a first distance, and two adjacent grooves on the second side have a second distance. The first distance is not equal to the second distance.

15. The battery cell according to any one of claims 1 to 6, characterized in that, The current collector includes two first connecting parts, which are symmetrically arranged about the second connecting part, and a buffer part is provided between the second connecting part and each of the first connecting parts.

16. A current collector, characterized in that, The current collector is disposed between the electrode assembly and the end cap of the battery cell. It includes a first connecting part, a second connecting part and a buffer part. The first connecting part is connected to the tab of the electrode assembly, and the second connecting part is connected to the electrode terminal of the end cap. The buffer section is located between the first connecting section and the second connecting section, and the buffer section has a groove that forms the deformation space of the buffer section.

17. A battery device, characterized in that, Includes the battery cell according to any one of claims 1 to 15.

18. An electrical appliance, characterized in that, Includes the battery cell according to any one of claims 1 to 15, or the battery device according to claim 17.

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