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 electrode assembly is arranged in a containing cavity, the end cover is assembled in a mounting opening and seals the containing cavity, the end cover comprises a plate body and a material adding part, the plate body is provided with a first surface and a second surface which are back to back in a first direction, and the material adding part is arranged on the first surface. The first surface is away from the electrode assembly, the second surface is close to the electrode assembly, the additive part is arranged on the second surface, at least part of the plate body and the additive part are connected with the shell in the second direction, and an included angle is formed between the first direction and the second direction. Therefore, by arranging the material adding part, when the end cover is constructed into a conventional end cover, the area of a welding area can be effectively increased, the welding strength can be improved, when the end cover is constructed into a thin end cover, the compatibility and the adaptability of a side welding scheme can be improved, a top welding scheme is replaced by the side welding scheme, the production efficiency of the single battery can be effectively improved, and the production cost is reduced. And the production cost of the battery monomer is reduced.

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, in the production process of battery cells, the end cap and the shell (usually an aluminum shell) need to be welded. However, in order to improve the welding efficiency of the end cap and the shell, in the prior art, the top welding is gradually replaced by the side welding. However, the applicability of the side welding is poor and it is difficult to ensure the 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, which has a higher structural strength and can improve the compatibility of side welding.

[0004] The present application also proposes a battery having the above-mentioned battery cell.

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

[0006] In the 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 is arranged in the accommodating cavity, the end cover is assembled at the mounting port and closes the accommodating cavity, the end cover comprises: a plate body and an additive part, the plate body having a first surface and a second surface opposite to each other in a first direction, the first surface is far away from the electrode assembly, and the second surface is close to the electrode assembly, the additive part is arranged on the second surface, at least part of the plate body and the additive part are connected to the shell in the second direction, and the first direction and the second direction are arranged at an angle.

[0007] According to the shell of the embodiment of the present application, by providing the additive part, when the end cover is constructed as a conventional end cover, the area of ​​the welding area can be effectively increased and the welding strength can be improved. When the end cover is constructed as a thin end cover, the effective welding size of the end cover in the first direction is adapted to the side welding scheme, which can improve the compatibility and adaptability of the side welding scheme. By replacing the top welding scheme with the side welding scheme, the production efficiency of the battery cell can be effectively improved and the production cost of the battery cell can be reduced.

[0008] According to some embodiments of the present application, the shell has a side plate, the additive part includes a first additive part arranged adjacent to the side plate and a second additive part located on a side of the first additive part away from the side plate, and a chamfer is arranged at one end of the first additive part away from the plate body.

[0009] In the above technical solution, on the one hand, by arranging a chamfer on the first additive part and performing assembly guidance through the chamfer, the difficulty of assembling the end cover to the shell in the first direction can be reduced, and the assembly convenience and assembly accuracy can be improved. On the other hand, the first additive part and the second additive part are both connected to the plate body, which can also further improve the structural strength of the end cover.

[0010] According to some embodiments of the present application, the chamfer angle α is 30° to 60°.

[0011] In the above technical solution, the chamfer angle is made more reasonable, so that the dimensions of the chamfered area in the first direction and the second direction are more reasonable, avoiding the chamfer angle being too small, resulting in poor installation guiding effect, and improving the reliability and stability of the guiding effect. At the same time, it can avoid the chamfer angle being too large, so that the dimension of the additive part in the second direction is more reasonable, reducing the occupation of the internal space of the shell by the additive part, so as to take into account the energy density of the battery cell.

[0012] According to some embodiments of the present application, a flange portion is provided on the peripheral side of the plate body, and the flange portion overlaps with the shell.

[0013] In the above technical solution, the welding area may include the overlapping surface between the flange portion and the side panel, the relative area between the plate body and the inner wall surface of the side panel, and the relative area between the first additive portion and the inner wall surface of the side panel. The welding area has a larger area, which can further improve the welding strength and reduce the probability of cracking. At the same time, the flange portion can limit the overall position of the end cover to prevent the end cover from sliding into the shell as a whole during the assembly process, thereby reducing the difficulty of welding.

[0014] According to some embodiments of the present application, the thickness of the plate body is a, the thickness of the additive part is b, the length of the right-angled side parallel to the plate body in the chamfered area is c, the thickness of the flange part is d, and the welding length of the end cover and the shell in the first direction is e=a+bdc*cotα.

[0015] In the above technical solution, by reasonably setting the welding length, that is, reasonably setting the size of the additive part in the first direction, the material cost can be reduced while improving the welding strength and the adaptability of the side welding solution, so as to reduce the production cost of the battery cell.

[0016] According to some embodiments of the present application, the length c of the right-angle side of the chamfered area parallel to the plate body satisfies: c≥0.3 mm.

[0017] In the above technical solution, the length of the right-angle side parallel to the chamfered area and the plate body is not less than 0.3 mm, so that the installation guiding effect of the chamfered area can remain stable, improve the guiding effect, and effectively reduce the difficulty of assembly between the end cover and the shell.

[0018] According to some embodiments of the present application, the thickness b of the additive portion satisfies: 0.3 mm ≤ b ≤ 2 mm.

[0019] Exemplarily, the thickness of the flange portion is generally 0.5mm, and the chamfer angle of the chamfered area is generally 45°. Taking the welding length not less than 1mm as an example, a+b needs to be ≥1.8mm, while the size of the conventional thin cover plate is 1.5mm, which cannot meet the welding standard. The thickness of the plate body of the present application is 1.5mm and the thickness of the additive part is not less than 0.3mm, which can meet the minimum value of a+b, so that the end cover can meet the welding length requirements of the side welding scheme, thereby improving welding reliability and welding quality.

[0020] In addition, it can be understood that limiting the thickness of the additive part to no more than 2 mm can not only reduce the material cost of the additive part, but also avoid the additive part being too long in the first direction, thereby improving the occupation of the internal space of the shell by the additive part.

[0021] According to some embodiments of the present application, the thickness b of the additive portion is 0.5 mm.

[0022] In the above technical solution, considering the comprehensive process manufacturing level, the thickness of the additive part is selected to be 0.5mm, which has lower processing difficulty, lower cost, and reasonable material cost. The structural strength and space occupancy after molding are more reasonable.

[0023] According to some embodiments of the present application, a projection of the additive portion in the first direction is annular.

[0024] In the above technical solution, the additive part can be welded and fixed to the side plate on the peripheral side of the shell, which improves the connection strength and reliability while increasing the connection area and suppressing the deformation of the shell due to welding stress.

[0025] According to some embodiments of the present application, the side plate includes a first side plate defining a large surface of the battery cell and a second side plate defining an end surface of the battery cell, and the additive portion includes a first additive segment and a second additive segment, the first additive segment is arranged opposite to the first side plate, and the second additive segment is arranged opposite to the second side plate.

[0026] In the above technical solution, the first material-adding section is connected to the first side plate, and the second material-adding section is connected to the second side plate, which can improve the connection strength and connection reliability between the first side plate and the end cover, and between the second side plate and the end cover.

[0027] According to some embodiments of the present application, the first additive segment is a plurality of discontinuous segments or a continuous segment, and the second additive segment is a plurality of discontinuous segments or a continuous segment.

[0028] In the above technical scheme, in an embodiment in which the first additive section and the second additive section are continuous, the connection area between the first side plate and the additive part, and between the second side plate and the additive part is larger, the welding uniformity effect is better, and the structural stability is higher. In an embodiment in which the first additive section and the second additive section are discontinuous, the local thickened area of ​​the end cover (i.e., the area where the first additive section and the second additive section are provided) occupies less space inside the shell, and has less energy storage capacity for the battery cell, so that both the structural strength of the shell and the energy density of the battery cell can be taken into account.

[0029] In a second aspect, the present application provides a battery, including: the battery cell in the above embodiment.

[0030] In a third aspect, the present application provides an electrical device, including: the battery in the above embodiment.

[0031] 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

[0032] 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:

[0033] Figure 1 is a schematic diagram of an electrical device according to an embodiment of the present application;

[0034] Figure 2 is a schematic diagram of disassembly of a battery according to an embodiment of the present application;

[0035] Figure 3 is a schematic diagram of a battery cell according to an embodiment of the present application;

[0036] Figure 4 is a schematic diagram of disassembling a battery cell according to an embodiment of the present application;

[0037] Figure 5 is a schematic diagram of the cooperation between the end plate and the side plate according to an embodiment of the present application;

[0038] Figure 6 yes Figure 5 The middle circle shows a partial enlarged schematic diagram of the E region;

[0039] Figure 7 is a schematic diagram of an end cover according to an embodiment of the present application.

[0040] Reference numerals:

[0041] Shell 10, mounting port 11, side plate 12, first side plate 121, second side plate 122, accommodating cavity 13,

[0042] end cap 20, first surface 20a, second surface 20b, plate body 21, flange portion 211, additive portion 22, first additive portion 221, second additive portion 222, first additive section 22a, second additive section 22b,

[0043] The electrode assembly 30,

[0044] Battery cell 300, battery 400, power device 500, controller 600, motor 700, box 800,

[0045] The first direction is X, and the second direction is Y. DETAILED DESCRIPTION

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] The term "plurality" used in the present application refers to two or more (including two).

[0056] 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.

[0057] 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.

[0058] 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 invention.

[0059] The battery mentioned in the embodiment of the present invention 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 mixed connection through a busbar.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] The technical solution described in the embodiment of the utility model is applicable to batteries and electrical devices using batteries.

[0066] 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, etc. 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, etc.; the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric airplane toy, etc.; the electric tool includes 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, etc. The embodiment of the utility model does not impose any special restrictions on the above-mentioned electrical devices.

[0067] For the convenience of description, the following embodiments are described by taking the electric device as a vehicle as an example.

[0068] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of the vehicle provided by some embodiments of the utility model. The interior of the vehicle is provided with a battery 400, and the battery 400 can be arranged at the bottom, head or tail of the vehicle. The battery 400 can be used for power supply of the vehicle, for example, the battery 400 can be used as the operating power supply of the vehicle.

[0069] 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.

[0070] In some embodiments of the present invention, the battery 400 can be used not only 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.

[0071] Please refer to the figure, Figure 2 The exploded view of the battery 400 provided in some embodiments of the present invention. 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).

[0072] 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, and the present invention has no particular limitation.

[0073] 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.

[0074] 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 battery cell 300, 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.

[0075] 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 12. The side plate 12 is arranged around the bottom plate and defines a receiving space with a mounting port 11. The electrode assembly 30 and other functional components may be arranged in the receiving space. The end cover 20 covers the mounting port 11 of the battery shell 10 to isolate the internal environment of the battery cell 300 from the external environment. The shape of the end cover 20 is adapted to the shape of the shell 10. The end cover 20 may be supported by a material with a certain hardness and strength (such as aluminum alloy, carbon fiber plate). The end cover 20 may effectively protect the safety and reliability of the internal components of the battery cell 300 during extrusion and collision.

[0076] 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.

[0077] 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 11 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 11. 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.

[0078] 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.

[0079] In the prior art, the end cap 20 needs to be welded to the shell 10 during the production process of the battery cell 300. Currently, the welding method of the end cap 20 and the shell 10 is mainly top welding, that is, the end cap 20 is sunk into the shell 10, and the weld is at the top, but the welding efficiency of top welding is not high. In order to improve production efficiency, a side technical solution has been developed. Side welding means that the end cap 20 is sunk into the shell 10, and the weld is on the side, and the end cap 20 and the shell 10 are welded together.

[0080] However, the applicability of side welding is poor, and it is only applicable to thicker end caps 20 (generally 2 mm and above). In some technical solutions, the thickness of the end cap 20 is less than 2 mm. For example, a 1.5 mm end cap 20 is used based on capacity requirements or cost reasons. In order to facilitate the end cap 20 to enter the shell, chamfering is required, resulting in a small amount of sinking of the end cap 20, a small weld width and a small weld depth, and it is difficult to ensure the welding strength.

[0081] In view of this, an embodiment of the utility model provides a battery cell 300, and an additive portion 22 is provided on the end cover 20, which can increase the welding area of ​​the end cover 20 and the side plate 12. The larger welding area can increase the welding width range, so that the welding strength of the shell 10 is higher and the structural stability is higher. At the same time, during the welding process, the thickness of the cover body of the end cover 20 has smaller restrictions on the process requirements of the side welding, which can improve the compatibility of the side welding.

[0082] Reference below Figure 1-Figure 7 A battery cell 300 , a battery 400 , and an electric device 500 according to an embodiment of the present application are described.

[0083] like Figure 3 and Figure 4 As shown, in a first aspect, the present application provides a battery cell 300 , and the battery cell 300 includes a shell 10 , an end cover 20 and an electrode assembly 30 .

[0084] See also Figure 5 and Figure 6 As shown, the shell 10 has a accommodating cavity 13 and an installation port 11 connected to the accommodating cavity 13, the electrode assembly 30 is arranged in the accommodating cavity 13, and the end cover 20 is assembled at the installation port 11. The end cover 20 includes: a plate body 21 and an additive part 22. The plate body 21 has a first surface 20a and a second surface 20b opposite to each other in a first direction, the first surface 20a is far away from the electrode assembly 30, and the second surface 20b is close to the electrode assembly 30. The additive part 22 is arranged on the second surface 20b. At least part of the plate body 21 and the additive part 22 are connected to the shell 10 in the second direction, and the first direction and the second direction are arranged at an angle.

[0085] 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.

[0086] Specifically, the plate body 21 has a first surface 20a and a second surface 20b in the first direction, i.e., an upper surface and a lower surface. The plate body 21 can be assembled to the shell 10 along the up and down directions, and then the additive part 22 is arranged on the lower surface. The additive part 22 and at least part of the side surfaces of the plate body 21 can be welded and fixed to the inner wall surface of the side plate 12.

[0087] It should be pointed out that the plate body 21 and the inner wall surface of the side plate 12 are welded and fixed, so that the side welding and fixing of the end cover 20 and the shell 10 can be realized, so as to improve the production utilization rate and improve the production efficiency. However, during the processing of the end cover 20, based on the consideration of assembly convenience, a chamfer needs to be set, and the chamfer area is spaced apart from the side plate 12 in the first direction, resulting in a reduction in the welding area between the end cover 20 and the shell 10 in the second direction. As the end cover 20 is required to be thinner and lower in cost, the thickness of the plate body 21 is getting smaller and smaller. The excessively small thickness of the plate body 21 will further reduce the welding area, resulting in the difficulty in ensuring the welding strength of the side welding scheme, which becomes a limitation of the side welding scheme and leads to poor applicability of the side welding scheme.

[0088] For example, in the prior art, the thickness of a conventional end cover is 2 mm, a 0.5 mm flange portion 211 is provided on the conventional end cover, and a chamfer is required on one side of the second surface 20b. If the chamfer is 0.3 mm, there is only a 1.5 mm straight edge area as a welding area. When a thin end cover is selected, the thickness of the thin end cover is 1.5 mm, the size of the flange portion 211 is still 0.5 mm, and the chamfer is 0.3 mm, then the size of the straight edge area is 0.7 mm, which cannot meet the weld width requirement of the side welding, resulting in limitations, and causing the side welding solution to be unable to adapt.

[0089] According to the battery cell 300 of the embodiment of the present application, by providing the additive part 22, when the end cover 20 is constructed as a conventional end cover, the area of ​​the welding area can be effectively increased and the welding strength can be improved. When the end cover 20 is constructed as a thin end cover, the effective welding size of the end cover 20 in the first direction is adapted to the side welding scheme, which can improve the compatibility and adaptability of the side welding scheme. By replacing the top welding scheme with the side welding scheme, the production efficiency of the battery cell 300 can be effectively improved and the production cost of the battery cell 300 can be reduced.

[0090] It should be noted that the additive part 22 can also improve the structural strength and rigidity of the end cover 20 , reduce the probability of bending and deformation of the end cover 20 , and improve the sealing stability and reliability of the battery cell 300 .

[0091] Combination Figure 5 and Figure 6 As shown, according to some embodiments of the present application, the shell 10 has a side plate 12, the additive portion 22 includes a first additive portion 221 arranged adjacent to the side plate 12 and a second additive portion 222 located on the side of the first additive portion 221 away from the side plate 12, and a chamfer is provided at one end of the first additive portion 221 away from the plate body 21.

[0092] Specifically, the additive part 22 includes a first part and a second part in the second direction. The additive part 22 is arranged inside the shell 10. Corresponding to the distinction between the inside and outside directions, the first part is the first additive part 221 located on the outside. The first additive part 221 is welded and fixed to the side plate 12, and the second additive part 222 is located on the inside of the first additive part 221.

[0093] Therefore, on the one hand, by setting a chamfer on the first additive part 221 and using the chamfer for assembly guidance, the difficulty of assembling the end cover 20 to the shell 10 in the first direction can be reduced, and the assembly convenience and assembly accuracy can be improved. On the other hand, the first additive part 221 and the second additive part 222 are both connected to the plate body 21, which can also further improve the structural strength of the end cover 20.

[0094] It should be pointed out that if Figure 6 As shown, in the second direction, the cross-sectional profile of the first additive portion 221 is a triangle or a trapezoid, and the cross-sectional profile of the second additive portion 222 is a rectangle.

[0095] It can be understood that the side of the end cover 20 can be divided into two areas arranged in sequence in the first direction, namely a straight edge area and a beveled edge area. The beveled edge area is defined by a chamfer, and the straight edge area is defined by at least part of the side of the plate body 21 and other side areas of the first additive part 221 except the chamfered part. By forming a chamfer and cooperating with a straight edge area with a larger size in the first direction compared to the prior art, the difficulty of assembling the end cover 20 and the shell 10 can be further reduced, and the assembly efficiency can be improved.

[0096] like Figure 6 As shown, according to some embodiments of the present application, the chamfer angle α is 30° to 60°.

[0097] Exemplarily, the chamfer angle is 30°, 45°, 60°, etc.

[0098] Thus, the chamfer angle is made more reasonable, so that the dimensions of the chamfered area in the first direction and the second direction are more reasonable, avoiding the chamfer angle being too small, resulting in poor installation guiding effect, and improving the reliability and stability of the guiding effect. At the same time, it can be avoided that the chamfer angle is too large, so that the dimension of the additive part 22 in the second direction is more reasonable, reducing the occupation of the internal space of the battery cell 300 by the additive part 22, so as to take into account the energy density of the battery cell 300.

[0099] According to some embodiments of the present application, a flange portion 211 is provided on the peripheral side of the plate body 21 , and the flange portion 211 overlaps with the shell 10 .

[0100] It can be understood that the present application sets an additive part 22 on the lower surface of the plate body 21 (i.e., the second surface 20b), and the area where the additive part 22 contacts the side plate 12 in the second direction can also be welded, so that through the setting of the additive part 22, the side surface of the additive part 22 and the inner wall surface of the side plate 12, and at least part of the side surface of the plate body 21 and the inner wall surface of the side plate 12 are side-welded and fixed, which can not only increase the welding area and improve the welding strength, but also when the end cover 20 is constructed as a thin end cover, through the setting of the additive part 22, it can also be welded and fixed to the side plate 12 through a side welding scheme, which can also improve the compatibility and adaptability of the side welding scheme and improve the production efficiency of the battery cell 300 of the embodiment of the present application.

[0101] Specifically, the flange portion 211 is formed on the outer surface of the plate body 21 and is generally annular and arranged around the plate body 21. The flange portion 211 is formed on one side of the first surface 20a of the plate body 21, and the lower surface of the flange portion 211 overlaps the end surface of the side plate 12.

[0102] Therefore, the welding area may include the overlapping surface between the flange portion 211 and the side panel 12, the relative area between the plate body 21 and the inner wall surface of the side panel 12, and the relative area between the first additive portion 221 and the inner wall surface of the side panel 12. The welding area has a larger area, which can further improve the welding strength and reduce the probability of cracking. At the same time, the flange portion 211 can limit the overall position of the end cover 20 to prevent the end cover 20 from sliding into the shell 10 as a whole during the assembly process, thereby reducing the difficulty of welding.

[0103] like Figure 6 As shown, according to some embodiments of the present application, the thickness of the plate body 21 is a, the thickness of the additive portion 22 is b, the length of the right-angled side parallel to the plate body 21 in the chamfered area is c, the thickness of the flange portion 211 is d, and the welding length of the end cover 20 and the shell 10 in the first direction is e=a+bdc*cotα.

[0104] That is to say, the straight side length of the end cover 20 in the second direction relative to the side plate 12 is e, and the value of e is related to the thickness a of the plate body 21, the thickness b of the additive part 22 (the dimension in the first direction), the length dimension of the chamfered area, the angle dimension and the thickness d of the flange part 211 (the dimension in the first direction), and satisfies the above formula: e=a+bdc*cotα.

[0105] Therefore, by reasonably setting the welding length, that is, reasonably setting the size of the additive part 22 in the first direction, the material cost can be reduced while improving the welding strength and the adaptability of the side welding scheme, so as to reduce the production cost of the battery cell 300.

[0106] According to some embodiments of the present application, the length c of the right-angled side of the chamfered area parallel to the plate body 21 satisfies: c≥0.3 mm.

[0107] For example, the length c of the right-angled side of the chamfered area parallel to the plate body 21 may be 0.3 mm, 0.4 mm, 0.5 mm, etc.

[0108] In this way, the length of the right-angle side parallel to the chamfered area and the plate body 21 is not less than 0.3 mm, so that the installation guiding effect of the chamfered area can be kept stable, improving the guiding effect, and effectively reducing the difficulty of assembling the end cover 20 and the shell 10.

[0109] like Figure 6 As shown, according to some embodiments of the present application, the thickness b of the additive portion 22 satisfies: 0.3 mm ≤ b ≤ 2 mm.

[0110] Exemplarily, the thickness of the flange portion 211 is generally 0.5mm, and the chamfer angle of the chamfered area is generally 45°. Taking the welding length not less than 1mm as an example, a+b needs to be ≥1.8mm, while the size of the conventional thin cover plate is 1.5mm, which cannot meet the welding standard. The thickness of the plate body 21 of the present application is 1.5mm and the thickness of the additive part 22 is not less than 0.3mm, which can meet the minimum value of a+b, so that the end cover 20 can meet the welding length requirement of the side welding scheme, thereby improving welding reliability and welding quality.

[0111] In addition, it can be understood that limiting the thickness of the additive part 22 to no more than 2 mm can not only reduce the material cost of the additive part 22, but also avoid the additive part 22 being too long in the first direction, thereby improving the occupation of the internal space of the shell 10 by the additive part 22.

[0112] According to some embodiments of the present application, the thickness b of the additive portion 22 is 0.5 mm.

[0113] In this way, considering the comprehensive process manufacturing level, the thickness of the additive part 22 is selected to be 0.5 mm, which has lower processing difficulty, lower cost, and reasonable material cost, and the structural strength and space occupancy after molding are more reasonable.

[0114] In some embodiments, the projection of the additive portion 22 in the first direction is annular.

[0115] It should be pointed out that the ring shape is a general term. In the embodiment where the shell 10 is cylindrical, the additive portion 22 is configured as a circular ring. In the embodiment where the shell 10 is rectangular, the additive portion 22 is configured as a rectangular ring or a racetrack ring.

[0116] Thus, the additive part 22 can be welded and fixed to the side plate 12 on the peripheral side of the shell 10, thereby improving the connection strength and reliability, increasing the connection area, and suppressing the deformation of the shell 10 due to welding stress.

[0117] Exemplarily, the side plate 12 includes a first side plate 121 that defines a large surface of the battery cell 300 and a second side plate 122 that defines an end surface of the battery cell 300, and the additive portion 22 includes a first additive segment 22a and a second additive segment 22b, the first additive segment 22a is arranged opposite to the first side plate 121, and the second additive segment 22b is arranged opposite to the second side plate 122.

[0118] That is to say, the first material-adding section 22a is connected to the first side plate 121, and the second material-adding section 22b is connected to the second side plate 122, which can improve the connection strength and connection reliability between the first side plate 121 and the end cover 20, and between the second side plate 122 and the end cover 20.

[0119] See also Figure 7 As shown, according to some embodiments of the present application, the first additive segment 22 a is a plurality of discontinuous segments or a continuous segment, and the second additive segment 22 b is a plurality of discontinuous segments or a continuous segment.

[0120] Specifically, in an embodiment in which the first additive segment 22a and the second additive segment 22b are continuous, the connection area between the first side plate 121 and the additive portion 22, and between the second side plate 122 and the additive portion 22 is larger, the welding uniformity effect is better, and the structural stability is higher. In an embodiment in which the first additive segment 22a and the second additive segment 22b are both discontinuous, the local thickened area of ​​the end cover 20 (i.e., the area where the first additive segment 22a and the second additive segment 22b are provided) occupies less space inside the shell 10, and has less energy storage capacity for the battery cell 300, and can take into account both the structural strength of the shell 10 and the energy density of the battery cell 300.

[0121] It can be understood that in the embodiment of the present application, in the embodiment where the end cap 20 is configured as a thin end cap, the welding length e can reach the same welding length as the conventional end cap. For example, for a 1.5 mm end cap 20, the chamfer is generally 0.3 mm, and if the thickness of the material-increasing portion 22 is 0.5 mm, the welding length = 1.5 (end cap 20 thickness) + 0.5 (material-increasing portion 22 thickness) - 0.5 (flange portion 211 thickness) - chamfer height = 1.5 - chamfer height.

[0122] Furthermore, if the welding length requirement is 1 mm on average, the chamfer height can be increased to 0.5 mm. A larger chamfer makes it easier and more convenient to insert the end cover 20 into the shell.

[0123] In a second aspect, the present application provides a battery 400 , comprising: the battery cell 300 in the above embodiment.

[0124] In a third aspect, the present application provides an electrical device 500, comprising: the battery 400 in the above embodiment.

[0125] 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 invention are known to those skilled in the art and will not be described in detail here.

[0126] 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.

[0127] 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 (13) and a mounting opening (11) communicating with the receiving cavity (13); An electrode assembly (30) is disposed in the accommodating cavity (13); An end cover (20), the end cover (20) being assembled on the mounting opening (11) and closing the accommodating cavity (13), the end cover (20) comprising: a plate body (21) and an additive part (22), the plate body (21) having a first surface (20a) and a second surface (20b) opposite to each other in a first direction, the first surface being away from the electrode assembly (30), and the second surface being close to the electrode assembly (30), the additive part (22) being arranged on the second surface (20b), at least a portion of the plate body (21) and the additive part (22) being connected to the shell (10) in a second direction, and the first direction and the second direction being arranged at an angle.

2. The battery cell according to claim 1, characterized in that: The shell (10) has a side plate (12), and the additive part (22) includes a first additive part (221) arranged adjacent to the side plate (12) and a second additive part (222) located on a side of the first additive part (221) away from the side plate (12), and a chamfer is arranged on one end of the first additive part (221) away from the plate body (21).

3. The battery cell according to claim 2, characterized in that: The chamfer angle α is 30° to 60°.

4. The battery cell according to claim 3, characterized in that: A flange portion (211) is provided on the circumferential side of the plate body (21), and the flange portion (211) overlaps the shell (10).

5. The battery cell according to claim 4, characterized in that: The thickness of the plate body (21) is a, the thickness of the material-added portion (22) is b, the length of the right-angled side of the chamfered area parallel to the plate body (21) is c, the thickness of the flange portion (211) is d, and the welding length of the end cover (20) and the shell (10) in the first direction is e=a+bdc*cotα.

6. The battery cell according to any one of claims 2 to 5, characterized in that: The length c of the right-angled side of the chamfered area parallel to the plate body (21) satisfies: c≥0.3 mm.

7. The battery cell according to any one of claims 1 to 5, characterized in that: The thickness b of the additive portion (22) satisfies: 0.3 mm ≤ b ≤ 2 mm.

8. The battery cell according to claim 7, characterized in that: The thickness b of the added material portion (22) is 0.5 mm.

9. The battery cell according to any one of claims 1 to 5, characterized in that: The projection profile of the added material portion (22) in the first direction is annular.

10. The battery cell according to any one of claims 2 to 5, characterized in that: The side plate (12) comprises a first side plate (121) defining a large surface of a battery cell (300) and a second side plate (122) defining an end surface of the battery cell (300); the additive portion (22) comprises a first additive section (22a) and a second additive section (22b); the first additive section (22a) is arranged opposite to the first side plate (121), and the second additive section (22b) is arranged opposite to the second side plate (122).

11. The battery cell according to claim 10, characterized in that: The first additive section (22a) is a plurality of discontinuous sections or a continuous section, and the second additive section (22b) is a plurality of discontinuous sections or a continuous section.

12. A battery (400), characterized in that: include: The battery cell (300) according to any one of claims 1 to 11.

13. An electrical device (500), characterized in that: include: The battery (400) of claim 12.

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