Battery cell, battery and electric device

Abstract

The utility model discloses a single battery, a battery and a power utilization device, the single battery comprises a shell, an electrode assembly and an end cover, the shell is provided with a containing cavity and an opening communicated with the containing cavity, the electrode assembly is arranged in the containing cavity, the end cover covers the opening and is provided with a mounting groove, one end, close to the opening, of the shell extends into the mounting groove, and the end, close to the opening, of the shell extends into the mounting groove. The part, extending into the mounting groove, of the shell is connected and matched with the end cover so as to seal the opening. Therefore, through the arrangement of the mounting groove, at least part of the shell extends into the mounting groove to be connected and matched with the end cover, the shell can be limited and self-locked through the side walls of the mounting groove on the two sides of the part, extending into the mounting groove, of the shell, and the coping capacity of a welding area to fatigue stress, the breathing effect and expansive force can be improved; the probability of cracking of the welding seam can be reduced, so that the reliability and the safety of the battery monomer are improved.

Description

Technical Field

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

[0002] In the related art, during the production process of battery cells, it is necessary to weld the end cover and the shell (usually an aluminum shell).

[0003] However, during the cyclic charge and discharge process of the battery cell, there are fluctuations in the internal air pressure, and breathing fatigue stress will be generated in the weld area between the end cover and the shell. In addition, the expansion force of the battery cell will increase during long-term use, which will also increase the fatigue stress in the weld area, resulting in an increased risk of cracking in the weld of the battery cell and reduced working stability and reliability of the battery cell. Utility Model Content

[0004] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present application is to provide a battery cell, which has a higher structural strength and a lower risk of cracking, and can improve the stability and reliability of the battery cell.

[0005] The present application also proposes a battery having the above-mentioned battery cell.

[0006] The present application further proposes an electrical device using the above battery.

[0007] In a first aspect, the present application provides a battery cell, comprising: a shell, an electrode assembly and an end cover, the shell having a accommodating cavity and an opening connected to the accommodating cavity, the electrode assembly is arranged in the accommodating cavity, the end cover is covered in the opening, and the end cover has a mounting groove, one end of the shell adjacent to the opening extends into the mounting groove, and the portion of the shell extending into the mounting groove is connected and cooperated with the end cover to seal the opening.

[0008] According to the battery cell of the embodiment of the present application, by providing a mounting groove, at least part of the shell extends into the mounting groove and is connected to and cooperated with the end cover, the shell can be limited and self-locked on both sides of the part of the shell extending into the mounting groove by the side walls of the mounting groove, which can improve the ability of the welding area to cope with fatigue stress, breathing effect and expansion force, and can reduce the probability of cracking in the weld, thereby improving the reliability and safety of the battery cell.

[0009] According to some embodiments of the present application, the end cover has a first side surface and a second side surface disposed opposite to each other, the mounting groove is extended around the circumference of the end cover, and the notch of the mounting groove faces the second side surface.

[0010] In the above technical solution, the mounting groove of the end cover on the second side surface is welded and fixed to the side plate. While improving the connection stability and reliability between the end cover and the shell, the mounting groove also has a limiting effect, which can prevent the end cover from sliding into the middle shell during assembly, thereby reducing the difficulty of assembly.

[0011] According to some embodiments of the present application, the end cover has a first plate and a second plate spaced apart in the circumferential direction of the end cover, the second plate is configured as an annular plate and is arranged around the first plate, and the portion of the shell extending into the mounting groove is located between the first plate and the second plate.

[0012] In the above technical solution, the installation groove is defined by the first wall and the second wall, which can not only improve the welding strength, but also improve the ability of the welding area to cope with fatigue stress, breathing effect and expansion force, and reduce the probability of cracking in the weld, thereby improving the reliability and safety of the battery cell. At the same time, the end cover and the shell can be connected by a side welding solution, which can also improve the processing efficiency of the battery cell.

[0013] According to some embodiments of the present application, the thickness of the second plate is 0.2 mm to 2 mm.

[0014] In the above technical solution, the wall thickness of the second plate is set within the value range of 0.2 mm to 2 mm, which can make the self-locking effect of the end cover better and take into account the space occupation.

[0015] According to some embodiments of the present application, the shell has a side plate and a bottom plate, the side plate is cylindrical, the bottom plate and the end cover are respectively arranged at both ends of the side plate, and the side plate extends into the installation groove.

[0016] In the above technical solution, the side plate, the bottom plate and the end cover define a sealed space, and the electrode assembly can be arranged in the sealed space. At the same time, the welding and fixation of the side plate to the mounting groove can improve the connection strength between the shell and the end cover, so as to reduce the probability of leakage, voltage instability and even short circuit during the operation of the battery cell, and improve the safety and reliability of the battery cell.

[0017] According to some embodiments of the present application, the side plate includes a first side plate that defines a large surface of the battery cell and a second side plate that defines a small surface of the battery cell, the second plate includes a first sub-plate corresponding to the first side plate and a second sub-plate corresponding to the second side plate, the thickness of the first side plate is the same or different from the thickness of the second side plate, and the thickness of the first sub-plate is the same or different from the thickness of the second sub-plate.

[0018] In the above technical scheme, in some embodiments, the sizes of the first sub-wall and the second sub-wall are the same, that is, the thickness of the second wall corresponding to the first side plate and the thickness of the second wall corresponding to the second side plate are consistent, which is convenient for processing, while in other embodiments, the sizes of the first sub-wall and the second sub-wall are different, and the sizes of the two can be set corresponding to the thickness of the first side plate and the second side plate. The thickness of the first side plate is smaller, corresponding to the smaller thickness of the first sub-wall, and the thickness of the second side plate is larger, corresponding to the larger thickness of the second sub-wall, so that the matching stability of the shell and the end cover is higher and the size is more reasonable.

[0019] According to some embodiments of the present application, the thickness of the first sub-board and the thickness of the second sub-board are both 0.2 mm to 2 mm.

[0020] In the above technical solution, the self-locking cooperation effect between the first side panel and the first sub-wall and the self-locking cooperation effect between the second side panel and the second sub-wall are more stable, and the dimensions of the width edge and the length edge of the battery cell are more reasonable, occupying less space, thereby improving the energy density of the battery.

[0021] According to some embodiments of the present application, the thickness of the first sub-board is 0.5 mm, and the thickness of the second sub-board is 1.0 mm.

[0022] In the above technical solution, the first side plate and the first sub-plate, and the second side plate and the second sub-plate can be better matched, and the self-locking effect of the first sub-plate on the first side plate and the self-locking effect of the second sub-plate on the second side plate can be more stable and reliable. At the same time, the space occupied by the end plate can be taken into account, so that the arrangement of multiple battery cells in the battery can be more compact to improve the energy density.

[0023] According to some embodiments of the present application, the difference between the thickness of the first side plate and the slot width of the mounting slot is 0.05 mm to 0.2 mm, and the difference between the thickness of the second side plate and the slot width of the mounting slot is 0.05 mm to 0.4 mm.

[0024] In the above technical solution, in the length direction of the shell, the groove width of the mounting groove is greater than the thickness of the first side plate, and in the width direction of the shell, the groove width of the mounting groove is greater than the thickness of the second side plate, so that the first side plate and the end cover, and the second side plate and the end cover are clearance-matched during assembly, which can reduce the difficulty of assembly.

[0025] More importantly, by limiting the above-mentioned range of values, the gap value between the first side plate and the end cover can be made more reasonable, as can the gap value between the second side plate and the end cover. Avoiding too small a gap value can reduce the difficulty of assembly, and avoiding too large a gap value can improve welding stability and reliability.

[0026] According to some embodiments of the present application, the difference between the thickness of the first side plate and the slot width of the mounting groove is 0.1 mm, and the difference between the thickness of the second side plate and the slot width of the mounting groove is 0.2 mm.

[0027] In the above technical solution, the gap between the first side plate with a smaller thickness and the mounting groove is smaller, and the gap between the second side plate with a larger thickness and the mounting groove is larger. Under the premise of making the assembly difficulty between the end cover and the side plate lower, the volume of the molten pool during welding of the thinner first side plate can be made smaller, and the volume of the molten pool during welding of the thicker second side plate can be made larger. This can not only improve the welding effect, but also improve the welding stress, reduce the deformation during the welding process of the shell and the end cover, and reduce the probability of weld cracking.

[0028] According to some embodiments of the present application, the depth of the mounting groove is 0.2 mm to 2 mm.

[0029] In the above technical solution, the groove depth of the installation groove is made more reasonable, which can avoid the groove depth being too shallow, resulting in limited limiting effect of the installation groove on the side plate, thereby improving the limiting reliability and stability of the installation groove. It can also avoid the groove depth being too deep, so as to take into account the thickness and structural strength of the end cover in the first direction, and reduce the processing difficulty of the end cover.

[0030] According to some embodiments of the present application, the groove depth is 1 mm.

[0031] In the above technical solution, the present application limits the groove depth to 1 mm, which can take into account the limiting effect of the installation groove and the structural strength and size requirements of the end cover.

[0032] In a second aspect, the present application provides a battery, including: the battery cell in the above embodiment.

[0033] In a third aspect, the present application provides an electrical device, including: the battery in the above embodiment.

[0034] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0036] Figure 1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0037] Figure 2 is a schematic diagram of disassembly of a battery according to an embodiment of the present application;

[0038] Figure 3is a schematic diagram of disassembling a battery cell according to an embodiment of the present application;

[0039] Figure 4 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0040] Figure 5 is a schematic diagram of the cooperation between the end cover and the side plate according to an embodiment of the present application;

[0041] Figure 6 is a schematic diagram of the cooperation between the end cover and the housing at an angle according to an embodiment of the present application;

[0042] Figure 7 yes Figure 6 The middle circle shows a partial enlarged schematic diagram of the D area;

[0043] Figure 8 is a schematic diagram of the cooperation between the end cover and the housing at another angle according to an embodiment of the present application;

[0044] Fig. 9 yes Figure 8 The middle circle shows a partial enlarged schematic diagram of area E.

[0045] Reference numerals:

[0046] End cap 100,

[0047] first side surface 11, second side surface 12, first board 20, second board 30, first sub-board 31, second sub-board 32, mounting groove 13,

[0048] Housing 200,

[0049] Side plate 210, first side plate 211, second side plate 212, bottom plate 220, accommodating cavity 230,

[0050] Battery cell 300, battery 400, power device 500, controller 600, motor 700, housing 800, electrode assembly 900,

[0051] The thickness A of the second board, the thickness A1 of the first sub-board, the thickness A2 of the second sub-board, the slot width B of the mounting groove, the slot depth C of the mounting groove, the first direction X, and the second direction Y. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as those commonly understood by technicians in the technical field of this application; the terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" in the specification and claims of this application and the above-mentioned drawings and any variations thereof are intended to cover non-exclusive inclusions. The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship.

[0054] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0055] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "attached" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0056] The term "and / or" in this application is only a description of the association relationship of associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this application generally indicates that the associated objects before and after are in an "or" relationship.

[0057] In the embodiments of the present application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width and other dimensions of various components in the embodiments of the present application shown in the drawings, as well as the overall thickness, length, width and other dimensions of the integrated device are only exemplary descriptions and should not constitute any limitation to the present application.

[0058] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0059] In the description of the present application, a first feature being “on” or “under” a second feature may include that the first and second features are directly in contact with each other, or may include that the first and second features are not in direct contact with each other but are in contact with each other via another feature therebetween.

[0060] In the description of the present application, “above”, “over” and “above” a first feature to a second feature includes the first feature being directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature.

[0061] The term "plurality" used in the present application refers to two or more (including two).

[0062] At present, the application of batteries is becoming more and more extensive. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power and hybrid solar power stations, but are also widely used in electric bicycles, electric motorcycles, electric car lights and electric transportation vehicles, as well as military equipment and aerospace and other fields. With the continuous expansion of battery application fields, its market demand is also constantly expanding.

[0063] The battery cell may be a secondary battery, which refers to a battery cell that can be continuously used by activating the active material by charging after the battery cell is discharged.

[0064] The battery cell can be a lithium ion battery, a sodium ion battery, a sodium lithium ion battery, a lithium metal battery, a sodium metal battery, a lithium sulfur battery, a magnesium ion battery, a nickel hydrogen battery, a nickel cadmium battery, a lead storage battery, etc., which is not limited in the embodiments of the present application.

[0065] The battery mentioned in the embodiments of the present application refers to a single physical module including one or more battery cells to provide higher voltage and capacity. When there are multiple battery cells, the multiple battery cells are connected in series, in parallel or in hybrid connection through a busbar.

[0066] In some embodiments, a plurality of battery cells may be combined into a battery unit, that is, when there are a plurality of battery cells, the plurality of battery cells are arranged and fixed to form a battery unit.

[0067] In some embodiments, the battery includes a case and a battery cell, at least one battery cell or at least one battery unit is accommodated in the case, and the case has an accommodating space, and at least one battery cell or at least one battery unit is accommodated in the accommodating space.

[0068] In some embodiments, the box body can be used as a part of the chassis structure of the vehicle. For example, part of the box body can become at least a part of the floor of the vehicle, or part of the box body can become at least a part of the cross beam and longitudinal beam of the vehicle.

[0069] In some embodiments, the battery or battery unit may be part of an energy storage system. The energy storage system may be an energy storage container, an energy storage cabinet, etc., in which the battery and the energy shutdown module are integrated.

[0070] The development of battery technology must take into account many design factors at the same time, such as energy density, cycle life, discharge capacity, charge and discharge rate and other performance parameters. In addition, the safety performance of the battery must also be considered.

[0071] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0072] The electrical device may be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, and the like. The vehicle may be a fuel vehicle, a gas vehicle, or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, and the like; the spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like; the electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, and the like; the electric tool may include a metal cutting electric tool, a grinding electric tool, an assembly electric tool, and an electric tool for railways, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator, and an electric planer, and the like. The embodiments of the present application do not impose any special restrictions on the above-mentioned electrical devices.

[0073] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0074] Please refer to Figure 1 , Figure 1 A schematic diagram of the structure of a vehicle provided in some embodiments of the present application. A battery 400 is provided inside the vehicle, and the battery 400 can be provided at the bottom, head, or tail of the vehicle. The battery 400 can be used to power the vehicle, for example, the battery 400 can be used as an operating power source for the vehicle.

[0075] The vehicle may further include a controller 600 and a motor 700 . The controller 600 is used to control the battery 400 to supply power to the motor 700 . The motor 700 serves as a load, for example, to meet the power requirements for starting, navigating and driving the vehicle.

[0076] In some embodiments of the present application, the battery 400 can not only be used as an operating power source for the vehicle, but also as a driving power source for the vehicle, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle.

[0077] Please refer to Figure 2 , Figure 2 The exploded view of the battery 400 provided in some embodiments of the present application. The battery 400 includes a battery cell and a box 800, and the box 800 is used to accommodate the battery cell (ie, a battery module).

[0078] Among them, the box body 800 is a component for accommodating the battery unit. The box body 800 provides a placement space for multiple battery cells 300 in the battery unit. The box body 800 can adopt a variety of structures. In some embodiments, the box body 800 may include a tray and a box body 800, and the tray and the box body 800 cover each other to define a placement space for accommodating the battery cells 300. The tray and the box body 800 can be in a variety of shapes, such as a cuboid, a cylinder, etc. The tray can be a hollow structure with one side open, and the box body 800 can also be a hollow structure with one side open. The open side of the box body 800 covers the open side of the tray, so as to form a box body 800 with a placement space. It can also be that the tray is a hollow structure with one side open, and the box body 800 is a plate-like structure. The box body 800 covers the open side of the tray, so as to form a box body 800 with a placement space. As an example, the battery cell 300 may be a cylindrical battery cell 300 , a prismatic battery cell 300 , or a battery cell 300 of other shapes, which is not particularly limited in the present application.

[0079] In the battery 400, there can be one or more battery cells 300. If there are more than one battery cell 300, the multiple battery cells 300 can be connected in series, in parallel, or in mixed connection. Mixed connection means that the multiple battery cells 300 are both connected in series and in parallel. Multiple battery cells 300 can be connected in series, in parallel, or in mixed connection to form a battery unit, and then the multiple battery units are connected in series, in parallel, or in mixed connection to form a whole, and accommodated in the box 800. Alternatively, all battery cells 300 can be directly connected in series, in parallel, or in mixed connection, and then the whole formed by all battery cells 300 is accommodated in the box 800.

[0080] The battery cell 300 serves as the smallest energy unit of a battery unit or a battery 400. A battery unit or a battery 400 includes a plurality of battery cells 300. The battery cell 300 includes a shell 200, an end cover 100, and an electrode assembly 900 disposed in the shell 200. The shell 200 is welded to the end cover 100. The large surface of the battery cell 300 is defined by the width edge and the length edge of the shell 200, the small surface of the battery cell 300 is defined by the width edge and the height edge, and the end surface of the battery cell 300 is defined by the length edge and the width edge.

[0081] The battery cell 300 includes: a shell 200, an end cover 100 and an electrode assembly 900 (not shown in the figure). The shell 200 may include a bottom plate 220 and a side plate 210. The side plate 210 is arranged around the bottom plate 220 and defines a receiving space with a mounting opening. The electrode assembly 900 and other functional components can be arranged in the receiving space. The end cover 100 covers the mounting opening of the shell 200 to isolate the internal environment of the battery cell 300 from the external environment. The shape of the end cover 100 is adapted to the shape of the shell 200. The end cover 100 can be supported by a material with a certain hardness and strength (such as aluminum alloy, carbon fiber plate), and the end cover 100 can effectively protect the safety and reliability of the internal components of the shell 200 during extrusion and collision.

[0082] In some embodiments, the end cap 100 may also be provided with a pressure relief mechanism for releasing the internal pressure when the internal pressure or temperature of the battery cell 300 reaches a threshold value. The material of the end cap 100 may also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiments of the present application do not impose any special restrictions on this. In some embodiments, an insulating member may also be provided on the inner side of the end cap 100, and the insulating member may be used to isolate the electrical connection components in the housing 200 from the end cap 100 to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, etc.

[0083] The shell 200 is a component used to cooperate with the end cap 100 to form the internal environment of the battery cell 300, wherein the formed internal environment can be used to accommodate the electrode assembly 900, the electrolyte and other components. The shell 200 and the end cap 100 can be independent components, and a mounting port can be set on the shell 200, and the internal environment of the battery cell 300 is formed by covering the mounting port with the end cap 100 at the mounting port. The shell 200 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylindrical shape, a hexagonal prism, etc. Specifically, the shape of the shell 200 can be determined according to the specific shape and size of the electrode assembly 900. The material of the shell 200 can be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and the embodiment of the present application does not impose any special restrictions on this.

[0084] The electrode assembly 900 is a component in the battery cell 300 where an electrochemical reaction occurs. One or more electrode assemblies 900 may be included in the housing 200. The electrode assembly 900 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The parts of the positive electrode sheet and the negative electrode sheet with active materials constitute the main body of the electrode assembly 900, and the parts of the positive electrode sheet and the negative electrode sheet without active materials each constitute a tab. The positive electrode tab and the negative electrode tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery 400, the positive electrode active material and the negative electrode active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0085] In the prior art, during the production process of the battery cell 300, it is necessary to weld the end cap 100 and the shell 200. After the end cap 100 and the shell 200 are welded, during the cyclic charge and discharge process, there are pressure fluctuations inside the shell 200, which will cause breathing fatigue stress in the weld area. In addition, the expansion force of the battery cell 300 will gradually increase during long-term use, which will also increase the risk of weld cracking, resulting in a decrease in the voltage of the battery cell 300 and an inability to use normally, thereby reducing the working stability and reliability of the battery cell 300.

[0086] In view of this, the embodiment of the present application provides an end cover 100. By setting a mounting groove 13 on the second side surface 12 of the end cover 100 and making the thickness A of the second plate 20 within the range of 0.2 mm to 2 mm, on the one hand, self-locking can be achieved between the end cover 100 and the shell 200, which can reduce the influence of internal and external stresses on the weld, and can improve the effect of the welding area in coping with fatigue stress, breathing effect and expansion force, thereby reducing the risk of cracking. On the other hand, the first plate 20 and the shell 200, the second plate 30 and the shell 200, and the end face of the side plate 210 of the shell can all be welded, and the area of ​​the welding area is larger, which can increase the molten pool area, increase the molten depth and molten width, and thus improve the welding strength.

[0087] Reference below Figure 3-Figure 9 The end cap 100 , the battery cell 300 , the battery 400 , and the electric device 500 according to the embodiment of the present application are described.

[0088] like Figure 3 and Figure 4 As shown, the present application provides a battery cell 300 , including: a shell 200 , an electrode assembly 900 and an end cover 100 .

[0089] See also Figure 5 , Figure 7 and Fig. 9As shown, the shell 200 has a accommodating cavity 230 and an opening connected to the accommodating cavity 230, the electrode assembly 900 is arranged in the accommodating cavity 230, the end cover 100 is covered on the opening, and the end cover 100 has a mounting groove 13, one end of the shell 200 adjacent to the opening extends into the mounting groove 13, and the part of the shell 200 that penetrates into the mounting groove 13 is connected and cooperated with the end cover 100 to seal the opening.

[0090] Specifically, at least a portion of the side plate 210 of the housing 200 extends into the mounting groove 13 , and the portion extending into the mounting groove 13 is connected and matched with the end cover 100 , such as being fixed by welding.

[0091] According to the battery cell 300 of the embodiment of the present application, by setting the installation groove 13, at least part of the shell 200 extends into the installation groove 13 and is connected to the end cover 100. The shell 200 can be limited and self-locked on both sides of the part of the shell 200 extending into the installation groove 13 by the side walls of the installation groove 13, which can improve the ability of the welding area to cope with fatigue stress, breathing effect and expansion force, reduce the probability of cracking in the weld, and thus improve the reliability and safety of the battery cell 300.

[0092] It should be pointed out that the battery cell 300 includes: an electrode assembly 900, an end cap 100 and a shell 200, the shell 200 is used to accommodate the electrode assembly 900, the shell 200 has an opening and a side plate 210 surrounding the opening, at least part of the side plate 210 is arranged in the mounting groove 13, the end cap 100 is connected to the shell 200 in the second direction, and the first direction is orthogonal to the second direction.

[0093] The end cover 100 and the shell 200 can be connected by penetration welding and side welding. The welding depth can exceed the wall thickness of the side plate 210. While the molten pool is larger, the molten depth can also be within a more easily controlled range, thereby improving the welding quality, so that the connection stability between the end cover 100 and the shell 200 is higher, the probability of cracking and failure is lower, and the working stability and reliability of the battery cell 300 are higher.

[0094] Specifically, the end cover 100 has a first side surface 11 and a second side surface 12 opposite to each other in a first direction. The mounting groove 13 is extended around the circumference of the end cover 100 , and the notch of the mounting groove 13 faces the second side surface 12 .

[0095] Therefore, the mounting groove 13 of the end cover 100 on the second side surface 12 is welded and fixed to the side plate 210. While improving the connection stability and reliability between the end cover 100 and the shell 200, the mounting groove 13 also has a limiting effect, which can prevent the end cover 100 from sliding into the middle shell 200 during the assembly process, thereby reducing the difficulty of assembly.

[0096] Furthermore, the end cover 100 has a first plate 20 and a second plate 30 spaced apart in the circumferential direction of the end cover 100 , the second plate 30 is constructed as an annular plate and is arranged around the first plate 20 , and the portion of the shell 200 extending into the mounting groove 13 is located between the first plate 20 and the second plate 30 .

[0097] Among them, the end cover 100 may include a cover body and a first plate 20 and a second plate 30 connected to the cover body, the first side surface 11 and the second side surface 12 are arranged back to back in a first direction, and the first plate 20 and the second plate 30 are spaced apart in a second direction perpendicular to the first direction, and define an installation groove 13, which is used to install the side plate of the shell of the battery cell 300.

[0098] The end cover 100 can be generally a plate structure, and the corresponding cover body and the first plate 20 define a cross-sectional profile with a convex cross-section, and the second plate 30 is connected to the cover body on the side facing the first side surface 11, the second plate 30 and the first plate 30 define a second side surface 12, and the second plate 30 surrounds the first plate 20 to form an installation groove 13.

[0099] It should be pointed out that the first direction can be the height direction (up and down direction, vertical direction) of the battery cell 300, that is, the X direction in the figure, and the corresponding second direction can be the length direction and width direction (horizontal direction, corresponding to the left and right direction of the large surface of the battery cell 300, corresponding to the front and back direction of the end face of the battery cell 300) of the battery cell 300, that is, the Y direction in the figure. That is to say, the end cover 100 is assembled to the shell 200 from the height direction, and can be welded to the shell 200 in the left and right direction and the front and back direction respectively.

[0100] Among them, the first side surface 11 refers to the side surface of the end cover 100 away from the shell 200, and the second side surface 12 refers to the side surface of the end cover 100 opposite to the electrode assembly 900. The first side surface 11 is basically parallel to the second side surface 12, and the thickness of the shell 200 remains basically unchanged.

[0101] Specifically, a mounting groove 13 distributed along the circumference of the end cover 100 is defined between the first plate 20 and the second plate 30, and when the side plate 210 is assembled with the end cover 100, the upper end of the side plate 210 can be assembled into the mounting groove 13, and the shell 200 is assembled and positioned by the mounting groove 13, which can improve the assembly accuracy, and the side plate 210 is embedded in the mounting groove 13, the inner side surface of the side plate 210 is opposite to the first plate 20, the upper end surface of the side plate 210 is opposite to the top wall of the mounting groove 13, and the outer side surface of the side plate 210 is opposite to the second plate 30, which can increase the contact area between the side plate 210 and the end cover 100, and the area of ​​the welding area is larger, which can increase the accommodating area, increase the fusion depth and fusion width, and improve the welding strength.

[0102] It can be understood that the side plate 210 is embedded in the installation groove 13, and the first plate 20 and the second plate 30 are located on both sides of the side plate 210 in the second direction. When the battery cell 300 is subjected to stress in the second direction, the end cover 100 has a limiting effect on the inward stress of the shell 200 and a weakening effect on the outward stress, so that the end cover 100 forms a self-locking effect on the shell 200, which can reduce the influence of internal stress and external stress on the weld, improve the welding area's ability to cope with fatigue stress, breathing effect and expansion force, and reduce the risk of cracking in the weld.

[0103] Therefore, by defining the installation groove 13 by the first plate 20 and the second plate 30, not only the welding strength can be improved, but also the ability of the welding area to cope with fatigue stress, breathing effect and expansion force can be improved, the probability of cracking in the weld can be reduced, and the reliability and safety of the battery cell 300 can be improved. At the same time, the end cover 100 and the shell 200 can be connected by a side welding solution, which can also improve the processing efficiency of the battery cell 300.

[0104] Furthermore, the thickness A of the second plate 20 is 0.2 mm to 2 mm.

[0105] Exemplarily, the thickness A of the second plate 20 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2 mm, etc.

[0106] It should be noted that when the thickness A of the second plate 20 is less than 0.2 mm, the size of the second plate 30 is too small, and the second plate 30 has poor effects on weakening outward stress and limiting inward stress. When the size of the second plate 30 is too large, the peripheral edge of the end cover 100 will protrude too much from the side of the shell 200, aggravating the space occupied by the battery cell 300 and affecting the energy density. Within the range of 0.2 mm to 2 mm, both the space occupation and the self-locking effect can be taken into account.

[0107] In this way, the wall thickness of the second plate 30 is within the value range of 0.2 mm to 2 mm, which can make the self-locking effect of the end cover 100 better and take into account the space occupation.

[0108] In some embodiments, the housing 200 has a side plate 210 and a bottom plate 220 . The side plate 210 is cylindrical. The bottom plate 220 and the end cover 100 are respectively disposed at two ends of the side plate 210 . The side plate 210 extends into the mounting groove 13 .

[0109] Thus, the side plate 210, the bottom plate 220 and the end cover 100 define a sealed space, and the electrode assembly 900 can be arranged in the sealed space. At the same time, the welding and fixation of the side plate 210 and the mounting groove 13 can improve the connection strength between the shell 200 and the end cover 100, so as to reduce the probability of leakage, voltage instability, and even short circuit during the operation of the battery cell 300, thereby improving the safety and reliability of the battery cell 300.

[0110] Combination Figure 5-Figure 9 As shown, according to some embodiments of the present application, the side plate 210 includes a first side plate 211 that defines a large surface of the battery cell 300 and a second side plate 212 that defines a small surface of the battery cell 300, the second plate 30 includes a first sub-plate 31 corresponding to the first side plate 211 and a second sub-plate 32 corresponding to the second side plate 212, the thickness of the first side plate 211 is the same as or different from the second side plate 212, and the thickness of the corresponding first sub-plate 31 and the second sub-plate 32 is the same as or different.

[0111] In other words, the thickness A1 of the first sub-plate 31 and the thickness A2 of the second sub-plate 32 may be the same or different in size.

[0112] In some embodiments, the first sub-plate 31 and the second sub-plate 32 have the same size, that is, the thickness of the second plate 20 corresponding to the first side plate 211 and the thickness of the second plate 20 corresponding to the second side plate 212 are consistent, which is convenient for processing. In other embodiments, the sizes of the first sub-plate 31 and the second sub-plate 32 are different. The sizes of the two can be set corresponding to the thickness of the first side plate 211 and the second side plate 212. The thickness of the first side plate 211 is smaller, and the corresponding thickness A1 of the first sub-plate 31 is smaller, and the thickness of the second side plate 212 is larger, and the corresponding thickness A2 of the second sub-plate 32 is larger, so that the matching stability of the shell 200 and the end cover 100 is higher and the size is more reasonable.

[0113] According to some embodiments of the present application, the thickness A1 of the first sub-plate 31 and the thickness A2 of the second sub-plate 32 are both 0.2 mm to 2 mm.

[0114] Specifically, the side panel 210 includes a first side panel 211 defining a length edge and a height edge, and a second side panel 212 defining a width edge and a height edge. The first sub-panel 31 is arranged corresponding to the first side panel 211, and the second sub-panel 32 is arranged corresponding to the second side panel 212. The thickness A1 of the first sub-panel 31 and the thickness A2 of the second sub-panel 32 are both within the range of 0.2 mm to 2 mm.

[0115] In this way, the self-locking matching effect between the first side plate 211 and the first sub-plate 31, and the self-locking matching effect between the second side plate 212 and the second sub-plate 32 are more stable, and the dimensions of the width edge and the length edge of the battery cell 300 are more reasonable, occupying less space, thereby improving the energy density of the battery 400.

[0116] Combination Figure 7 and Fig. 9 As shown, according to some embodiments of the present application, the thickness A1 of the first sub-plate 31 is 0.5 mm, and the thickness A2 of the second sub-plate 32 is 1.0 mm.

[0117] It should be pointed out that the thickness of the first side plate 211 and the second side plate 212 of the shell 200 can be different. Commonly, the thickness of the first side plate 211 defining the large surface of the battery cell 300 is less than the thickness of the second side plate 212 defining the end surface of the battery cell 300. The thickness A2 of the second sub-plate 32 corresponding to the second side plate 212 with a larger thickness is 1 mm, and the thickness A1 of the first sub-plate 31 corresponding to the first side plate 211 with a smaller thickness is 0.5 mm.

[0118] In this way, the first side plate 211 and the first sub-plate 31, as well as the second side plate 212 and the second sub-plate 32 can be better matched, and the self-locking effect of the first sub-plate 31 on the first side plate 211 and the self-locking effect of the second sub-plate 32 on the second side plate 212 can be more stable and reliable. At the same time, the space occupied by the end plate can be taken into account, so that the arrangement of multiple battery cells 300 in the battery 400 can be more compact to improve the energy density.

[0119] like Figure 7 and Fig. 9 As shown, according to some embodiments of the present application, the difference between the thickness of the first side plate 211 and the slot width B of the mounting slot 13 is 0.05mm-0.2mm, and the difference between the thickness of the second side plate 212 and the slot width B of the mounting slot 13 is 0.05mm-0.4mm.

[0120] Exemplarily, the difference between the thickness of the first side plate 211 and the groove width B is 0.05mm, 0.1mm, 0.15mm, 0.2mm, etc., and the difference between the thickness of the second side plate 212 and the groove width B is 0.05mm, 0.1mm, 0.15mm, 0.2mm, 0.25mm, 0.3mm, 0.35mm, 0.4mm, etc.

[0121] It should be pointed out that in the length direction of the shell 200, the groove width B of the installation groove 13 is greater than the thickness of the first side plate 211, and in the width direction of the shell 200, the groove width B of the installation groove 13 is greater than the thickness of the second side plate 212, so that the first side plate 211 and the end cover 100, and the second side plate 212 and the end cover 100 can be clearance-matched during the assembly process, which can reduce the difficulty of assembly.

[0122] More importantly, by limiting the above-mentioned range of values, the gap value between the first side plate 211 and the end cover 100 can be made more reasonable, as can the gap value between the second side plate 212 and the end cover 100. This can avoid the gap value being too small, thereby reducing the difficulty of assembly, and avoid the gap value being too large, thereby improving welding stability and reliability.

[0123] In some embodiments, the slot width B of the installation slot 13 corresponding to the first side panel 211 area is consistent with the slot width B of the installation slot 13 corresponding to the second side panel 212 area. In other embodiments, the slot width corresponding to the second side panel 212 area is greater than the slot width corresponding to the first side panel 211 area.

[0124] According to some embodiments of the present application, the difference between the thickness of the first side plate 211 and the slot width B of the mounting slot 13 is 0.1 mm, and the difference between the thickness of the second side plate 212 and the slot width B of the mounting slot 13 is 0.2 mm.

[0125] As a result, the gap between the first side plate 211 with a smaller thickness and the mounting groove 13 is smaller, and the gap between the second side plate 212 with a larger thickness and the mounting groove 13 is larger. Under the premise of making the assembly difficulty between the end cover 100 and the side plate 210 lower, the volume of the molten pool during welding of the thinner first side plate 211 can be made smaller, and the volume of the molten pool during welding of the thicker second side plate 212 can be made larger, which can not only improve the welding effect, but also improve the welding stress, reduce the deformation during the welding of the shell 200 and the end cover 100, and reduce the probability of weld cracking.

[0126] like Figure 5 , Figure 7 and Fig. 9 As shown, according to some embodiments of the present application, the groove depth C of the mounting groove 13 is 0.2 mm to 2 mm.

[0127] Exemplarily, the groove depth C of the mounting groove 13 in the first direction is 0.2 mm, 0.4 mm, 0.6 mm, 0.8 mm, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2 mm, etc.

[0128] In this way, the groove depth C of the installation groove 13 is made more reasonable, and it can be avoided that the groove depth C is too shallow, resulting in limited limiting effect of the installation groove 13 on the side plate 210, thereby improving the limiting reliability and stability of the installation groove 13. It can also be avoided that the groove depth C is too deep, so as to take into account the thickness and structural strength of the end cover 100 in the first direction, thereby reducing the processing difficulty of the end cover 100.

[0129] According to some embodiments of the present application, the groove depth C is 1 mm.

[0130] It should be pointed out that the thickness of the end cover 100 is generally 2 mm to 3 mm, and a chamfer of about 0.5 mm is provided. In fact, in the first direction, the end cover 100 can set the effective height of the mounting groove 13 to be 1.5 mm to 2.5 mm, and based on the structural strength requirements of the end cover 100, the thickness of the end cover 100 needs to be set below 2 mm.

[0131] Furthermore, the present application limits the groove depth C to 1 mm, which can take into account the limiting effect of the installation groove 13 and the structural strength and size requirements of the end cover 100.

[0132] The present application provides a battery 400 , comprising: the battery cell 300 in the above embodiment.

[0133] The present application provides an electric device 500, comprising: the battery 400 in the above embodiment.

[0134] Other structures and operations of the end cap 100 , the battery cell 300 , the battery 400 and the electrical device 500 according to the embodiment of the present application are known to those skilled in the art and will not be described in detail here.

[0135] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0136] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A battery cell, characterized in that: include: A housing (200) having a receiving chamber (230) and an opening communicating with the receiving chamber (230); An electrode assembly (900) is disposed in the accommodating cavity (230); An end cover (100) is arranged on the opening, and the end cover (100) has a mounting groove (13), one end of the shell (200) adjacent to the opening extends into the mounting groove (13), and the portion of the shell (200) extending into the mounting groove (13) is connected and matched with the end cover (100) to seal the opening.

2. The battery cell according to claim 1, characterized in that: The end cover (100) has a first side surface (11) and a second side surface (12) disposed opposite to each other, the mounting groove (13) is extended around the circumference of the end cover (100), and the notch of the mounting groove (13) faces the mounting groove (13) on the second side surface (12).

3. The battery cell according to claim 2, characterized in that: The end cover (100) comprises a first plate (20) and a second plate (30) which are spaced apart in the circumferential direction of the end cover (100); the second plate (30) is constructed as an annular plate and is arranged around the first plate (20); the portion of the housing (200) extending into the mounting groove (13) is located between the first plate (20) and the second plate (30).

4. The battery cell according to claim 3, characterized in that: The thickness of the second plate (30) is 0.2 mm to 2 mm.

5. The battery cell according to claim 3, characterized in that: The housing (200) comprises a side plate (210) and a bottom plate (220); the side plate (210) is cylindrical; the bottom plate (220) and the end cover (100) are respectively arranged at two ends of the side plate (210); and the side plate (210) extends into the installation groove (13).

6. The battery cell according to claim 5, characterized in that: The side plate (210) comprises a first side plate (211) defining a large surface of the battery cell (300) and a second side plate (212) defining a small surface of the battery cell (300); the second plate (30) comprises a first sub-plate (31) corresponding to the first side plate (211) and a second sub-plate (32) corresponding to the second side plate (212); the thickness of the first side plate (211) and the second side plate (212) are the same or different; the thickness of the first sub-plate (31) and the second sub-plate (32) are the same or different.

7. The battery cell according to claim 6, characterized in that: A first sub-plate and a second sub-plate, wherein the thickness A1 of the first sub-plate (31) and the thickness A2 of the second sub-plate (32) are both 0.2 mm to 2 mm.

8. The battery cell according to claim 6 or 7, characterized in that: The thickness of the first sub-plate (31) is 0.5 mm, and the thickness of the second sub-plate (32) is 1.0 mm.

9. The battery cell according to claim 6 or 7, characterized in that: The difference between the thickness of the first side plate (211) and the slot width of the mounting groove (13) is 0.05 mm to 0.2 mm, and the difference between the thickness of the second side plate (212) and the slot width of the mounting groove (13) is 0.05 mm to 0.4 mm.

10. The battery cell according to claim 9, characterized in that: The difference between the thickness of the first side plate (211) and the slot width of the mounting groove (13) is 0.1 mm, and the difference between the thickness of the second side plate (212) and the slot width of the mounting groove (13) is 0.2 mm.

11. The battery cell according to any one of claims 1 to 5, characterized in that: The groove depth of the installation groove (13) is 0.2 mm to 2 mm.

12. The battery cell according to claim 11, characterized in that: The groove depth is 1 mm.

13. A battery (400), characterized in that: include: The battery cell (300) according to any one of claims 1 to 12.

14. An electrical device (500), characterized in that: include: The battery (400) of claim 13.

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