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 a mounting port communicated with the containing cavity, the electrode assembly is arranged in the containing cavity, the end cover is assembled at the mounting port along a first direction, the end cover is connected with the shell in a second direction, and the end cover is arranged in the containing cavity. A containing part is arranged in the connecting area of the end cover and the shell and suitable for containing welding flux, and an included angle is formed between the first direction and the second direction. According to the battery monomer disclosed by the embodiment of the invention, the accommodating part is arranged, and the accommodating part is suitable for accommodating the welding flux for welding, so that the expected weld penetration depth and weld width can be achieved, the welding strength is improved, high-power welding equipment does not need to be adopted or the power of the welding equipment does not need to be increased, and the welding cost can be reduced; the thermal stress and the welding stress in the welding process are improved, the deformation of the battery monomer is reduced, and the durability and the reliability of the battery monomer are improved.

Description

Technical Field

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

[0002] In the related art, in the production process of battery cells, the end cap and the shell (usually an aluminum shell) need to be welded. However, the welding between the end cap and the shell is a butt welding. In order to achieve the expected weld penetration and width and improve the welding strength, it is necessary to increase the welding power, increase the cost, and cause large thermal stress, large deformation after welding, and limited welding strength. Utility Model Content

[0003] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, one object of the present application is to provide a battery cell having a higher structural strength and a lower welding cost.

[0004] The present application also proposes a battery using the above-mentioned battery monomer.

[0005] The present application further proposes an electrical device having the battery.

[0006] 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 a mounting port connected to the accommodating cavity, the electrode assembly being arranged in the accommodating cavity, the end cover being assembled at the mounting port along a first direction, the end cover being connected to the shell in a second direction, and a accommodating portion being arranged in a connection area between the end cover and the shell, the accommodating portion being suitable for accommodating solder, and the first direction being arranged at an angle to the second direction.

[0007] According to the battery cell of the embodiment of the present application, by providing a receiving portion, and the receiving portion is suitable for receiving solder for welding, not only can the expected weld penetration depth and width be achieved and the welding strength be improved, but also there is no need to use high-power welding equipment or increase the power of the welding equipment, which can reduce the welding cost, improve the thermal stress and welding stress in the welding process, reduce the deformation of the battery cell, and improve the durability and reliability of the battery cell.

[0008] According to some embodiments of the present application, the housing and / or the end cover defines a receiving portion.

[0009] In the above technical solution, based on the setting requirements of the shell and the end cover, a receiving portion can be provided on at least one of the shell or the end plate, and the solder can be accommodated in the receiving portion to increase the melting width and melting depth, thereby improving the structural strength and rigidity of the battery cell, reducing the probability of cracking and failure in the welding area, and improving the stability and reliability of the battery cell.

[0010] According to some embodiments of the present application, the end cover has a first welding groove, the shell has a second welding groove, and the first welding groove and the second welding groove are assembled in the second direction to form an accommodating portion.

[0011] In the above technical solution, by setting the first welding groove and the second welding groove, when welding the shell and the end cover, a certain amount of solder can be accommodated in the first welding groove and the second welding groove, which can improve the strength of the weld and reduce the dependence of the welding quality on the assembly accuracy of the cover plate and the shell, so that the consistency of the entire circle of the annular weld is better.

[0012] According to some embodiments of the present application, the groove angle of the first welding groove is A, the groove height of the first welding groove is B, the side plate thickness of the shell is C, and it satisfies: B*tanA≤C.

[0013] In the above technical scheme, the groove width of the first welding groove can be made smaller than the thickness of the side plate, so that the size of the first welding groove is closer to the size of the second welding groove, avoiding the second welding groove from being too large, so that the solder accommodation degree of the first welding groove and the second welding groove is similar, thereby making the consistency of the entire circle of the weld better.

[0014] According to some embodiments of the present application, the thickness of the end cover is F, the groove height of the first welding groove is B, and the following condition is satisfied: B<F-0.5mm.

[0015] In the above technical solution, the groove height can be made smaller than the thickness of the end cover, so that the outer side surface of the end cover and the inner wall surface of the side plate have a contact surface of at least about 0.5 mm, so as to improve the sealing of the battery cell.

[0016] According to some embodiments of the present application, the groove angle of the second welding groove is D, the groove height of the second welding groove is E, the side plate thickness of the shell is C, and it satisfies: E*tanD≤C.

[0017] In the above technical solution, the groove width of the second welding groove can be made smaller than the thickness of the side plate, so that one side edge of the side plate in the first direction can be flush with the first surface, which can further prevent solder and weld scars from overflowing the accommodating portion, thereby improving the welding strength and the aesthetics of the battery cell.

[0018] According to some embodiments of the present application, the thickness of the end cover is F, the groove height of the second welding groove is E, and the following condition is satisfied: E<F-0.5mm.

[0019] In the above technical solution, the groove height of the second welding groove can be made smaller than the thickness of the end cover, so that the outer side surface of the end cover and the inner wall surface of the side plate have a contact surface of at least about 0.5 mm to improve the sealing of the battery cell.

[0020] According to some embodiments of the present application, the first welding groove and the second welding groove have the same outline size.

[0021] In the above technical solution, the solder in the first welding groove and the second welding groove can be made more consistent, which can improve the welding strength and improve the overall consistency of the weld. This can further improve the welding stress, reduce the probability of weld cracking, and improve the structural strength and stability of the battery cell.

[0022] In a second aspect, the present application provides a battery, including: the battery cell in the above embodiment.

[0023] In a third aspect, the present application provides an electrical device, including: the battery in the above embodiment.

[0024] 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

[0025] 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:

[0026] Figure 1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0027] Figure 2 is a schematic diagram of disassembly of a battery according to an embodiment of the present application;

[0028] Figure 3 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0029] Figure 4 It is a schematic diagram of the cooperation between the end cap and the side plate according to the application which is private;

[0030] Figure 5 yes Figure 4 The middle circle shows a partial enlarged schematic diagram of the G area.

[0031] Reference numerals:

[0032] Shell 10, side plate 11, accommodating cavity 12,

[0033] End cap 20, electrode assembly 30,

[0034] Battery cell 300, battery 400, power device 500, controller 600, motor 700, box 800,

[0035] Accommodating portion a, first welding groove a1, second welding groove a2,

[0036] The groove angle of the first welding groove is A, the groove height of the first welding groove is B, the side plate thickness of the shell is C, the groove angle of the second welding groove is D, the groove height of the second welding groove is E, the thickness of the end cover is F, the first direction is X, and the second direction is Y. DETAILED DESCRIPTION

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] The term "plurality" used in the present application refers to two or more (including two).

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] The technical solutions described in the embodiments of the present application are applicable to batteries and electrical devices using batteries.

[0057] 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.

[0058] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0059] Please refer to Figure 1 , Figure 1A 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.

[0060] 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.

[0061] 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.

[0062] 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).

[0063] 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.

[0064] 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.

[0065] 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 10, an end cover 20, and an electrode assembly 30 disposed in the shell 10. The shell 10 is welded to the end cover 20. The large surface of the battery cell 300 is defined by the width edge and the length edge of the shell 10, 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.

[0066] The battery cell 300 includes: a shell 10, an end cover 20 and an electrode assembly 30. The shell 10 may include a bottom plate and a side plate 11. The side plate 11 is arranged around the side of the bottom plate and defines a receiving space with a mounting opening. The electrode assembly 30 and other functional components can be arranged in the receiving space. The end cover 20 covers the mounting opening of the shell 10 to isolate the internal environment of the battery cell 300 from the external environment. The shape of the end cover 20 is compatible with the shape of the shell 10. The end cover 20 can be supported by a material with a certain hardness and strength (such as aluminum alloy, carbon fiber plate), and the end cover 20 can effectively protect the safety and reliability of the internal components of the shell 10 during extrusion and collision.

[0067] In some embodiments, the end cap 20 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 20 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 20, and the insulating member may be used to isolate the electrical connection components in the housing 10 from the end cap 20 to reduce the risk of short circuit. Exemplarily, the insulating member may be plastic, rubber, etc.

[0068] The shell 10 is a component used to cooperate with the end cap 20 to form the internal environment of the battery cell 300, wherein the formed internal environment can be used to accommodate the electrode assembly 30, the electrolyte and other components. The shell 10 and the end cap 20 can be independent components, and a mounting port can be set on the shell 10, and the internal environment of the battery cell 300 is formed by covering the opening of the end cap 20 at the mounting port. The shell 10 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 10 can be determined according to the specific shape and size of the electrode assembly 30. The material of the shell 10 can 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.

[0069] The electrode assembly 30 is a component in the battery cell 300 where electrochemical reactions occur. One or more electrode assemblies 30 may be included in the housing 10. The electrode assembly 30 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly 30, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or at both ends of the main body, respectively. During the charge and discharge process of the battery 400, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop.

[0070] In the prior art, during the production process of the battery cell 300, the end cover 20 and the shell 10 need to be welded, and the welding between the end cover 20 and the shell 10 is a butt welding. In order to ensure the welding strength and reliability between the end cover 20 and the shell 10 and reduce the risk of weld cracking, it is necessary to increase the welding power, which increases the cost. Moreover, the greater the welding power, the greater the thermal stress, the greater the deformation after welding, and it is difficult to ensure the welding strength.

[0071] In view of this, an embodiment of the present application provides a battery cell 300, which can achieve the expected welding depth and welding width by setting an accommodation portion a on the welding area between the end cover 20 and the shell 10, thereby improving the welding strength, and the welding power does not need to be set too high, which can improve thermal stress and reduce the deformation of the shell 10 after welding.

[0072] Reference below Figure 1-Figure 5 A battery cell 300 , a battery 400 , and an electric device 500 according to an embodiment of the present application are described.

[0073] like Figure 3 and Figure 4 As shown, in the first aspect, the present application provides a battery cell 300, including: a shell 10, an electrode assembly 30 and an end cover 20, the shell 10 has a accommodating cavity 12 and a mounting port connected to the accommodating cavity 12, the end cover 20 is assembled at the mounting port along a first direction, the end cover 20 is connected to the shell 10 in a second direction, and a accommodating portion a is provided in the connection area between the end cover 20 and the shell 10, the accommodating portion a is suitable for accommodating solder, and the first direction and the second direction are arranged at an angle.

[0074] It should be pointed out that the first direction and the second direction may be arranged at an angle so that they are orthogonal, or they may have an acute angle or an obtuse angle. The first direction may be the height direction (up and down direction, vertical direction) of the battery cell 300, i.e., the X direction in the figure, and the corresponding second direction may 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 surface of the battery cell 300) of the battery cell 300, i.e., the Y direction in the figure. That is to say, the end cover 20 is assembled to the shell 10 from the height direction, and may be welded to the shell 10 in the left and right direction and the front and back direction, respectively.

[0075] Among them, the end cover 20 has a first surface and a second surface opposite to each other in the first direction and an outer side surface located in the second direction. The outer side surface of the end cover 20 is arranged opposite to the inner wall surface of the shell 10 and is fixed by welding. The shell 10 includes a bottom plate and a side plate 11. The side plate 11 is surrounded by the bottom plate to define an installation space with one end open, and the open opening is the installation opening. The end cover 20 is installed to the shell 10 along the first direction, and the end cover 20 and the shell 10 are welded and fixed in the second direction.

[0076] Specifically, an accommodating portion a is provided on the connection area between the end cover 20 and the shell 10. When the shell 10 and the end cover 20 are welded, the accommodating portion a can be used to accommodate the solder. In addition, the solder is provided during the welding process to assist in filling the accommodating portion a, thereby expanding the molten pool and the molten block, so as to improve the welding strength between the shell 10 and the end cover 20, reduce the welding stress, and reduce the welding deformation.

[0077] It should be noted that by providing an accommodating portion a and providing solder in the accommodating portion a, auxiliary welding can be performed using the solder to achieve the desired weld penetration depth and width. There is no need to use high-power welding equipment or increase the power of the welding equipment, which can reduce welding costs and reduce thermal stress during welding, thereby improving deformation of the battery cell 300 after welding and improving welding strength.

[0078] In addition, during the welding process, the filled solder and the weld scars produced by welding are all located in the accommodating portion a, which can ensure that the outer surfaces of the shell 10 and the end cover 20 are flat. While ensuring the welding quality, the aesthetics of the battery cell 300 can also be improved to ensure the beautiful welding morphology.

[0079] In summary, according to the battery cell 300 of the embodiment of the present application, by providing a receiving portion a, and the receiving portion a is suitable for receiving solder for welding, not only can the expected weld penetration depth and width be achieved and the welding strength be improved, but also there is no need to use high-power welding equipment or increase the power of the welding equipment, which can reduce the welding cost, improve the thermal stress and welding stress in the welding process, reduce the deformation of the battery cell 300, and improve the durability and reliability of the battery cell 300.

[0080] According to some embodiments of the present application, the housing 10 and / or the end cover 20 defines a receiving portion a.

[0081] That is, in some embodiments, an accommodating portion a is formed on the inner wall surface and the end surface of the shell 10 facing the end cover 20; in other embodiments, an accommodating portion a is formed on the outer side surface and the first surface of the shell 10 facing the end cover 20; in still other embodiments, a first part of the accommodating portion a is formed on the inner wall surface and the end surface of the shell 10 facing the end cover 20, and a second part of the accommodating portion a is formed on the outer side surface and the first surface of the shell 10 facing the end cover 20, and the first part and the second part are combined to form the accommodating portion a.

[0082] Therefore, based on the setting requirements of the shell 10 and the end cover 20, an accommodating portion a can be set on at least one of the shell 10 or the end plate, and the solder can be accommodated by the accommodating portion a to increase the melting width and melting depth, thereby improving the structural strength and rigidity of the battery cell 300, reducing the probability of cracking and failure in the welding area, and improving the stability and reliability of the battery cell 300.

[0083] The accommodation portion a may be formed as an accommodation groove, an accommodation hole, an accommodation cavity, etc.

[0084] like Figure 4 and Figure 5 As shown, according to some embodiments of the present application, the end cover 20 has a first welding groove a1, and the shell 10 has a second welding groove a2. The first welding groove a1 and the second welding groove a2 are assembled in the second direction to form an accommodating portion a.

[0085] Specifically, the first welding groove a1 and the second welding groove a2 can be assembled to form a V-shaped, U-shaped, or arc-shaped receiving portion a.

[0086] In this way, by setting the first welding groove a1 and the second welding groove a2, when welding the shell 10 and the end cover 20, a certain amount of solder can be accommodated in the first welding groove a1 and the second welding groove a2, which can improve the strength of the weld and reduce the dependence of the welding quality on the assembly accuracy of the cover plate and the shell 10, so that the consistency of the entire circle of the annular weld is better.

[0087] See also Figure 4 and Figure 5 As shown, according to some embodiments of the present application, the groove angle of the first welding groove a1 is A, the groove height of the first welding groove a1 is B, the thickness of the side plate 11 of the shell 10 is C, and it satisfies: B*tanA≤C.

[0088] Exemplarily, the groove angle A of the first welding groove a1 is 45°, and the thickness C of the side plate 11 is 1 mm, then the height range of the first welding groove a1 is B≤1 mm, where B*tanA can be used to obtain the groove width of the first welding groove a1 in the second direction, corresponding to making the groove width in the second direction less than or equal to the thickness of the side plate 11.

[0089] In this way, the groove width of the first welding groove a1 can be made smaller than the thickness C of the side plate 11, so that the size of the first welding groove a1 is closer to the size of the second welding groove a2, avoiding the second welding groove a2 from being too large, so that the solder accommodation degree of the first welding groove a1 and the second welding groove a2 is similar, thereby making the consistency of the entire circle of the weld better.

[0090] Combination Figure 4 and Figure 5 As shown, according to some embodiments of the present application, the thickness of the end cover 20 is F, the groove height of the first welding groove a1 is B, and the following condition is satisfied: B<F-0.5mm.

[0091] Thus, the groove height B of the first welding groove a1 can be made smaller than the thickness F of the end cover 20 , so that the outer side surface of the end cover 20 and the inner wall surface of the side plate 11 have a contact surface of at least about 0.5 mm, thereby improving the sealing performance of the battery cell 300 .

[0092] like Figure 4 and Figure 5 As shown, according to some embodiments of the present application, the groove angle of the second welding groove a2 is D, the groove height of the second welding groove a2 is E, the thickness of the side plate 11 of the shell 10 is C, and it satisfies: E*tanD≤C.

[0093] Exemplarily, the groove angle D of the second welding groove a2 is 45°, and the thickness C of the side plate 11 is 1 mm, then the height range of the second welding groove a2 is B≤1 mm, where B*tanA can be used to obtain the groove width of the second welding groove a2 in the second direction, corresponding to making the groove width in the second direction less than or equal to the thickness C of the side plate 11.

[0094] In this way, the groove width of the second welding groove a2 can be made smaller than the thickness C of the side plate 11, and the side edge of the side plate 11 in the first direction can be flush with the first surface, which can further prevent solder and weld scars from overflowing the accommodating portion a, thereby improving the welding strength and the aesthetics of the battery cell 300.

[0095] According to some embodiments of the present application, the thickness of the end cover 20 is F, the groove height of the second welding groove a2 is E, and the following condition is satisfied: E<F-0.5mm.

[0096] Thus, the groove height E of the second welding groove a2 can be made smaller than the thickness F of the end cover 20 , so that the outer side surface of the end cover 20 and the inner wall surface of the side plate 11 have a contact surface of at least about 0.5 mm, thereby improving the sealing performance of the battery cell 300 .

[0097] According to some embodiments of the present application, the first welding groove a1 and the second welding groove a2 have the same outline size.

[0098] In this way, the solder in the first welding groove a1 and the second welding groove a2 can be made more consistent, which can improve the welding strength and improve the overall consistency of the weld, further improve the welding stress, reduce the probability of weld cracking, and improve the structural strength and stability of the battery cell 300.

[0099] It should be pointed out that the end cover 20 and the shell 10 can be connected by top welding, and the welding depth is less than the wall thickness of the side plate 11, but the molten pool is larger, which can improve the welding quality, so that the connection stability between the end cover 20 and the shell 10 is higher, the probability of cracking failure is lower, and the working stability and reliability of the battery cell 300 are higher.

[0100] In a second aspect, the present application provides a battery 400 , comprising: the battery cell 300 in the above embodiment.

[0101] In a third aspect, the present application provides an electrical device 500, comprising: the battery 400 in the above embodiment.

[0102] Other structures and operations of the end cap 20 , the battery cell 300 , the battery 400 and the electrical device 500 according to the embodiment of the present application are well known to those skilled in the art and will not be described in detail here.

[0103] 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.

[0104] 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 (10), the housing (10) comprising a receiving cavity (12) and a mounting opening communicating with the receiving cavity (12); An electrode assembly (30), the electrode assembly (30) being arranged in the accommodating cavity (12); An end cover (20), wherein the end cover (20) is assembled to the mounting opening along a first direction and closes the accommodating cavity (12), the end cover (20) is connected to the shell (10) in a second direction, and a receiving portion (a) is provided in a connection area between the end cover (20) and the shell (10), the receiving portion (a) is suitable for accommodating solder, and the first direction and the second direction are arranged at an angle.

2. The battery cell according to claim 1, characterized in that: The housing (10) and / or the end cover (20) define the accommodating portion (a).

3. The battery cell according to claim 1 or 2, characterized in that: The circumferential side edge of the end cover (20) has a first welding groove (a1), and the side plate (11) of the shell (10) has a second welding groove (a2), and the first welding groove (a1) and the second welding groove (a2) are assembled in the second direction to form the accommodating portion (a).

4. The battery cell according to claim 3, characterized in that: The groove angle of the first welding groove (a1) is A, the groove height of the first welding groove (a1) is B, the thickness of the side plate (11) of the shell (10) is C, and the following condition is satisfied: B*tanA≤C.

5. The battery cell according to claim 3, characterized in that: The thickness of the end cover (20) is F, the groove height of the first welding groove (a1) is B, and the following condition is satisfied: B<F-0.5mm.

6. The battery cell according to claim 3, characterized in that: The groove angle of the second welding groove (a2) is D, the groove height of the second welding groove (a2) is E, the thickness of the side plate (11) of the shell (10) is C, and the following condition is satisfied: E*tanD≤C.

7. The battery cell according to claim 3, characterized in that: The thickness of the end cover (20) is F, the groove height of the second welding groove (a2) is E, and the following condition is satisfied: E<F-0.5mm.

8. The battery cell according to any one of claims 4 to 7, characterized in that: The first welding groove (a1) and the second welding groove (a2) have the same outline dimensions.

9. A battery (400), characterized in that: include: The battery cell (300) according to any one of claims 1 to 8.

10. An electrical device (500), characterized in that: include: The battery (400) as claimed in claim 9.

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