Battery cell, battery, and electrical device

Abstract

Disclosed are a battery cell (20), a battery, and an electrical device. The battery cell (20) comprises: a housing assembly (21), comprising a housing (211), a terminal (212), and a cover plate (213), wherein the housing (211) has a first wall (2111), a hole (211a) is provided in the first wall (2111), the terminal (212) comprises a connecting portion (2122) and a body portion (2121) which are connected to each other, the body portion (2121) is located inside of the first wall (2111), the connecting portion (2122) passes through the hole (211a), the connecting portion (2122) has a flanged portion (201) and a first accommodating recess (202), the flanged portion (201) is located outside the first wall (2111) and is away from the hole (211a), the first accommodating recess (202) is close to the side of the center of the hole (211a), the first accommodating recess (202) comprises at least two stepped recesses, and the cover plate (213) is arranged on one of the at least two stepped recesses close to the body portion (2121); and an electrode assembly (22), wherein the electrode assembly (22) is arranged in the housing (211) and is electrically connected to the body portion (2121) or the connecting portion (2122).

Description

Battery cells, batteries and electrical devices

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application is based on the Chinese patent application with application number: 202410002307.9 and application date of January 2, 2024, and claims the priority of the Chinese patent application. The entire content of the Chinese patent application is hereby introduced into this application as a reference. Technical Field

[0003] 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

[0004] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component of new energy vehicles, batteries have high safety and service life requirements. However, during the manufacturing process, the battery cells within the battery have covers welded to the terminals. This welding of the covers to the terminals presents reliability issues, impacting the reliability of the battery cells.

[0005] Summary of the Invention

[0006] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the reliability of the battery cell, and further improve the reliability of the battery and the electrical device.

[0007] In the first aspect, an embodiment of the present application provides a battery cell, comprising: a shell assembly, comprising a shell, a pole and a cover plate, the shell having a first wall, the first wall being provided with a through hole, the pole comprising a main body portion and a connecting portion connected to each other, the main body portion being located on the inner side of the first wall, the connecting portion being passed through the through hole, the connecting portion having a folding portion and a first accommodating groove, the folding portion being located on the outer side of the first wall and away from the through hole, the first accommodating groove being close to the center side of the through hole, the first accommodating groove comprising at least two step grooves, the cover plate being provided on one of the at least two step grooves close to the main body portion; an electrode assembly, the electrode assembly being provided in the shell and electrically connected to the main body portion or the connecting portion.

[0008] In the above technical solution, the terminal is configured to include a connected main body and a connecting portion, the connecting portion having a first receiving groove, and the first receiving groove including at least two stepped grooves. When the terminal's connecting portion is folded to form the folded portion, the step groove near the main body is less likely to experience edge collapse and large rounded corners. By placing the cover plate over the step groove near the main body, the probability of a large gap between the cover plate and the corresponding step groove can be reduced, thereby reducing the probability of problems such as flash points during welding, which is beneficial for improving the reliability of the battery cell. Secondly, because the first receiving groove includes at least two stepped grooves, the riveting die can effectively squeeze the material during the riveting and flanging process, improving the regularity of the weld interface dimensions.

[0009] In some embodiments of the present application, there are at least three step grooves. In this technical solution, by providing at least three step grooves, at least one step groove can be left between the step groove near the folding portion and the step groove near the main body portion, further reducing the probability of edge collapse and large rounded corners in the step groove near the main body portion, further reducing the probability of cracking points when welding the cover plate and the connecting portion, and further improving the reliability of the battery cell.

[0010] In some embodiments of the present application, the step groove where the cover plate is located is a first groove, and in the groove depth direction of the first groove, the thickness of the cover plate is less than or equal to the groove depth of the first groove.

[0011] In the above technical solution, the thickness of the cover plate can be less than the depth of the first groove, and the outer surface of the cover plate can be lower than the outer edge of the first groove. This can increase the distance between the outer surface of the cover plate and the collapsed edge and large fillet, reducing the impact of the collapsed edge and large fillet on the cover plate welding. The thickness of the cover plate can also be equal to the depth of the first groove. The outer surface of the cover plate is flush with the outer edge of the first groove, which not only facilitates welding and improves welding quality, but also improves the aesthetics of the weld between the cover plate and the connecting part.

[0012] In some embodiments of the present application, the first groove has a depth of greater than or equal to 0.6 mm. In this technical solution, by setting the first groove depth to be greater than or equal to 0.6 mm, the first groove can have an appropriate groove depth, thereby ensuring higher strength of the terminal column and also ensuring an appropriate thickness of the cover plate, thereby improving the strength of the cover plate and the connecting portion after welding, improving the reliability of the housing assembly, and thus improving the reliability of the battery cell.

[0013] In some embodiments of the present application, the stepped groove in which the cover plate is located is a first groove, and the first groove is located on the side of the first wall away from the body. In this technical solution, because the first groove is connected to the cover plate, the position of the first groove relative to the first wall affects the position of the cover plate relative to the first wall. By arranging the first groove on the side of the first wall away from the body, the cover plate is located outside the first wall and farther away from the inside of the housing. This reduces the probability of contact between the cover plate and the electrode assembly, facilitating welding of the cover plate to the connecting portion or the body.

[0014] In some embodiments of the present application, the stepped groove in which the cover plate is located is a first groove having a first groove surface. A cover side surface is formed around the periphery of the cover plate, and the cover side surface and the first groove surface are disposed opposite each other, with a gap formed between the cover side surface and the first groove surface. In this technical solution, the gap formed between the cover side surface and the first groove surface can be used to place solder, allowing the cover plate and the first groove to be connected via filler welding. This allows for faster welding speeds between the cover plate and the first groove, reduces the requirements for welding assembly, and improves welding efficiency.

[0015] In some embodiments of the present application, the stepped groove in which the cover plate resides is a first groove having a first groove surface. A cover side surface is formed around the periphery of the cover plate. The cover side surface and the first groove surface are disposed opposite each other and abut against each other. In this technical solution, the gap between the cover side surface and the first groove surface is relatively small, allowing the cover plate and the first groove to be connected by autogenous welding. This ensures a high-quality connection between the cover plate and the first groove, facilitating welding, and eliminating the need for additional material for the weld seam, thereby reducing costs.

[0016] In some embodiments of the present application, the shell includes a shell body and an end cover, the shell body has an opening, the end cover is arranged to cover the opening, and the shell body or the end cover forms a first wall.

[0017] In the above technical solution, the shell body can form a first wall, allowing the shell body of the battery cell to protrude from the terminal post. This solution can simplify the structure of the end cap, facilitating a lightweight design of the end cap. Since the end cap and the shell body are connected, the end cap has a simple structure and is lightweight, which can improve the reliability of the connection between the end cap and the shell body. The end cap can also form a first wall, allowing the end cap of the battery cell to protrude from the terminal post. Since the end cap and the shell body are separate components, this solution simplifies the connection between the terminal post and the first wall, reduces the requirements for the terminal post installation process, improves the efficiency of the terminal post installation, and reduces costs.

[0018] In some embodiments of the present application, the connecting part has a second accommodating groove, the second accommodating groove is connected to the first accommodating groove, the main body is provided with a connecting hole connected to the second accommodating groove, the electrode assembly includes a connected active material coating part and a conductive part, the conductive part is passed through the connecting hole and is electrically connected to the main body or the connecting part.

[0019] In the above technical solution, a second accommodating groove connected to the first accommodating groove is provided in the connecting portion, and a connecting hole connected to the second accommodating groove is provided in the main body portion, and the conductive portion is passed through the connecting hole and electrically connected to the main body portion or the connecting portion. This not only reduces the weight of the pole, but also allows the conductive portion of the electrode assembly to be arranged in the second accommodating groove, saving space in the shell, thereby providing more space for the active material coating portion of the electrode assembly, which is conducive to arranging a larger volume of active material coating portion, thereby improving the energy density of the battery cell.

[0020] In some embodiments of the present application, the one located on the outermost side of the shell among the at least two step grooves is the second groove. In the groove depth direction of the second groove, the groove depth of the second groove is T1, and the thickness of the folded portion is T2, wherein T1 / T2≥0.5.

[0021] In the above technical solution, by setting the ratio between the groove depth T1 of the second groove and the thickness T2 of the folded portion in the groove depth direction of the second groove to be greater than or equal to 0.5, the second groove can have an appropriate groove depth. When the connection portion is partially riveted and flanged to form a folded portion, the second groove has a larger groove depth to accommodate collapsed edges and large rounded corners, thereby reducing the probability of collapsed edges and large rounded corners spreading out of the second groove, which is beneficial to reducing the probability of a large gap between the cover plate and the first groove, and improving the welding reliability of the cover plate and the first groove.

[0022] In some embodiments of the present application, the step groove where the cover plate is located is a first groove, the first groove has a first groove surface opposite to the peripheral side surface of the cover plate, the connecting portion has a first side surface close to the side wall of the via and a second side surface close to the center of the via, the distance between the first side surface and the second side surface is L1, and the distance between the first groove surface and the first side surface is L2, wherein 1 / 2≤L2 / L1≤2 / 3.

[0023] In the above technical solution, by setting the ratio of the distance L1 between the first side surface and the second side surface of the connecting part to the distance L2 between the first groove surface and the first side surface in the range of 1 / 2 to 2 / 3, on the one hand, the part of the connecting part close to the folding part can have an adaptive strength, reducing the probability of local weak points and the probability of stress concentration leading to cracking, thereby improving the reliability of the connecting part; on the other hand, the first groove can have an adaptive groove surface to support the cover plate, reducing the occurrence of poor installation reliability between the cover plate and the first groove due to insufficient support, which is conducive to improving the installation reliability between the cover plate and the first groove.

[0024] In some embodiments of the present application, the stepped groove in which the cover plate is located is a first groove, and the first groove has adjacent first and second groove surfaces. The first groove surface is opposite the peripheral side surface of the cover plate, and the second groove surface is closer to the inner side of the housing. A chamfer is formed between the first and second groove surfaces. In this technical solution, the chamfer can provide guidance for the cover plate to enter the groove, improving the assembly efficiency of the cover plate. The chamfer also facilitates demolding when forming the first groove surface on the connecting portion, which helps reduce the manufacturing difficulty of the connecting portion.

[0025] In some embodiments of the present application, the chamfer angle is 5 to 15 degrees. In this technical solution, by setting the chamfer angle within the range of 5 to 15 degrees, the chamfer is within an appropriate angle range. On the one hand, the chamfer has a better guiding effect and better mold drafting efficiency. On the other hand, it can also make the straight groove surface of the first groove have an appropriate height, so that the cover plate and the first groove have better bonding and connection reliability.

[0026] In some embodiments of the present application, the height of the first groove surface is greater than or equal to 0.4 mm in the groove depth direction of the first groove. In this technical solution, by ensuring that the height of the first groove surface is greater than or equal to 0.4 mm in the groove depth direction of the first groove, an effective straight-edge welding area is created between the cover plate and the first groove surface during welding, thereby achieving higher welding strength between the cover plate and the first groove and improving the connection reliability between the cover plate and the first groove.

[0027] In a second aspect, the present application also provides a battery, comprising the battery cell described above.

[0028] In the above technical solution, the use of this battery cell can reduce the probability of a large gap appearing between the cover plate and the first receiving groove when the pole is riveted and flanged, and reduce the probability of explosion points and the like occurring when the cover plate is welded, so that the battery cell has higher reliability, thereby improving the reliability of the battery.

[0029] In a third aspect, the present application also provides an electrical device comprising the aforementioned battery cell or battery.

[0030] In the above technical solution, the use of this battery cell can reduce the probability of a large gap appearing between the cover plate and the first receiving groove when the pole is riveted and flanged, and reduce the probability of explosion points and the like occurring when the cover plate is welded, so that the battery cell and the battery have higher reliability, thereby improving the reliability of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0032] FIG1 is a schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0033] FIG2 is an exploded view of the structure of a battery provided in some embodiments of the present application;

[0034] FIG3 is a schematic diagram of the three-dimensional structure of a battery cell provided in some embodiments of the present application;

[0035] FIG4 is a top view of a battery cell provided in some embodiments of the present application;

[0036] FIG5 is a schematic diagram of FIG4 taken along line AA;

[0037] FIG6 is a partial enlarged view of point I in FIG5;

[0038] FIG7 is a partial enlarged view of point II in FIG5;

[0039] FIG8 is a schematic diagram of a partial structure of a battery cell provided in some embodiments of the present application;

[0040] FIG9 is an exploded view of a battery cell provided in some embodiments of the present application.

[0041] Icons: 1000, vehicle; 100, battery; 10, housing; 11, first housing body; 12, second housing body; 20, battery cell; 21, housing assembly; 211, housing; 2111, first wall; 2111a, pressure relief hole; 2112, housing; 2112a, opening; 2113, end cap; 211a, through hole; 212, pole; 2121, main body; 2121a, connecting hole; 2122, connecting part; 2122a, first side surface; 2122b, second side surface; 201, folding part; 202, first accommodating groove; 2021, first groove; 2021a, first groove surface; 2021b, second groove surface; 2021c, inverted Corner; 2022, second groove; 203, second receiving groove; 2001, positive pole; 2002, negative pole; 213, cover plate; 213a, cover side; 22, electrode assembly; 221, active material coating portion; 222, conductive portion; 23, first insulating member; 24, second insulating member; 25, sealing member; 26, pressure relief portion; 261, explosion-proof disk; 262, protective patch; 200, controller; 300, motor; X, first direction; Y, second direction; Z, third direction. DETAILED DESCRIPTION

[0042] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" 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-secondary relationship.

[0044] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0045] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0046] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0047] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0048] The term "plurality" used in this application refers to two or more (including two).

[0049] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0050] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or battery pack. A battery generally includes a casing that encloses one or more battery cells or multiple battery modules. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0051] A battery cell includes a casing, an electrode assembly, and an electrolyte. The casing is used to hold the electrode assembly and the electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. The battery cell mainly relies on the movement of metal ions between the positive electrode sheet and the negative electrode sheet to work. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer. The positive electrode active material layer is coated on the surface of the positive electrode collector. The positive electrode collector not coated with the positive electrode active material layer protrudes from the positive electrode collector coated with the positive electrode active material layer. The positive electrode collector not coated with the positive electrode active material layer serves as the positive electrode tab. Taking lithium-ion batteries as an example, the material of the positive electrode collector can be aluminum, and the positive electrode active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode sheet consists of a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative current collector. The negative current collector uncoated with the negative active material layer protrudes from the negative current collector coated with the negative active material layer. The negative current collector uncoated with the negative active material layer serves as the negative electrode tab. The negative current collector can be made of copper, and the negative active material can be carbon, silicon, or other materials. To ensure that high currents can pass without melting, multiple positive electrode tabs are stacked together, and multiple negative electrode tabs are stacked together.

[0052] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0053] New energy vehicles have experienced rapid growth in recent years. Within the electric vehicle sector, power batteries, as the power source, play an irreplaceable and important role. A battery consists of a housing and multiple cells housed within it. As a core component of new energy vehicles, batteries have high safety and service life requirements. However, during the manufacturing process, a cover plate is welded to the terminal post within the battery cell. This welding process can lead to reliability issues, impacting the reliability of the battery cell.

[0054] The inventors discovered that in a battery cell structure, the pole is provided with a receiving groove. During the manufacture of the battery cell, the pole is inserted into a through-hole in the housing, and the portion of the pole wall forming the receiving groove can be fixed to the housing by riveting and flanging. In this case, the flanging portion of the pole forms a folded portion, and the cover plate can be arranged in the receiving groove and welded to the inner side of the folded portion to be fixed to the pole. The cover plate can then be used to electrically connect to an external conductor. However, during this process, due to the influence of the thickness of the material in the area where the folded portion of the pole is located, the folded portion of the folded portion near the receiving groove is prone to collapse and large rounded corners. This will result in a relatively large gap when riveting the pole and cover plate during assembly, which can easily cause problems such as explosion points during welding, thereby affecting the reliability of the battery cell.

[0055] Based on the above considerations, in order to solve the problem that explosion points are easily present when welding the pole and the cover plate due to the collapsed edge and large rounded corners of the folded part of the pole, the inventor designed a battery cell, including a shell assembly and an electrode assembly, the shell assembly including a shell, a pole and a cover plate, the shell having a first wall, the first wall being provided with a through hole, the pole including a main body portion and a connecting portion connected, the main body portion being located on the inner side of the first wall, the connecting portion being passed through the through hole, the connecting portion having a folded portion and a first accommodating groove, the folded portion being located on the outer side of the first wall and away from the through hole, the first accommodating groove being close to the center side of the through hole, the first accommodating groove including at least two step grooves, the cover plate being provided on one of the at least two step grooves close to the main body portion; the electrode assembly is provided in the shell and electrically connected to the main body portion or the connecting portion.

[0056] In a battery cell of this structure, the pole is arranged to include a connected main body and a connecting portion, the connecting portion has a first accommodating groove, and the first accommodating groove includes at least two step grooves. When the connecting portion of the pole is folded to form a folded portion, the probability of collapsed edges and large rounded corners occurring in the step groove close to the main body is relatively low. By arranging the cover plate on the step groove close to the main body, the probability of a large gap occurring between the cover plate and the corresponding step groove can be reduced, and the probability of problems such as explosion points occurring during welding can be reduced, which is beneficial to improving the reliability of the battery cell.

[0057] The battery disclosed in the embodiments of the present application can be used, but is not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in the present application can be used to form the electrical device.

[0058] The present invention provides an electric device that uses a battery as a power source. The electric device may include, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, 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 spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, and the like.

[0059] For the convenience of explanation, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application. Please refer to FIG1 , which is a schematic structural diagram of a vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, to meet the power requirements of the vehicle 1000 during startup, navigation and driving.

[0060] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0061] Please refer to Figure 2, which is an exploded view of the structure of a battery 100 provided in some embodiments of the present application. The battery 100 includes a housing 10 and a plurality of battery cells 20, which are intended to be accommodated within the housing 10. The housing 10 is used to provide an assembly space for the battery cells 20, and the housing 10 can adopt a variety of structures. In some embodiments, the housing 10 can include a first housing body 11 and a second housing body 12, which cover each other and together define an assembly space for accommodating the battery cells 20. The second housing body 12 can be a hollow structure with one end open, and the first housing body 11 can be a plate-like structure, with the first housing body 11 covering the open side of the second housing body 12, so that the first housing body 11 and the second housing body 12 jointly define an assembly space. The first housing body 11 and the second housing body 12 can also be hollow structures with one end open, with the open side of the first housing body 11 covering the open side of the second housing body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0062] In the battery 100, the multiple battery cells 20 can be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 can be directly connected in series, in parallel, or in a hybrid configuration, and then the entire structure of the multiple battery cells 20 is housed within the housing 10. Alternatively, the battery 100 can be constructed by first connecting the multiple battery cells 20 in series, in parallel, or in a hybrid configuration to form a battery module, which is then connected in series, in parallel, or in a hybrid configuration to form a single structure and housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0063] Please refer to Figure 2, which is an exploded view of the structure of the battery 100 provided in some embodiments of the present application. The battery 100 includes multiple rows of battery cells 20. The multiple rows of battery cells 20 can be arranged along the length direction of the box 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the width direction of the box 10; or, the multiple rows of battery cells 20 can be arranged along the width direction of the box 10, and each row of battery cells 20 includes multiple battery cells 20 arranged along the length direction of the box 10. Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be cylindrical, flat, rectangular, or other shapes. For example, in Figure 2, the battery cell 20 is in the shape of a rectangular parallelepiped.

[0064] According to some embodiments of the present application, referring to Figures 3 to 6, Figure 3 shows a battery cell 20 provided by some embodiments of the present application, including a shell assembly 21 and an electrode assembly 22, the shell assembly 21 including a shell 211, a pole 212 and a cover plate 213, the shell 211 has a first wall 2111, the first wall 2111 is provided with a through hole 211a, the pole 212 includes a main body portion 2121 and a connecting portion 2122 connected to each other, the main body portion 2121 is located on the inner side of the first wall 2111, and the connecting portion 2122 is located on the inner side of the first wall 2111. 22 is passed through the through hole 211a, and the connecting part 2122 has a folding part 201 and a first accommodating groove 202. The folding part 201 is located on the outside of the first wall 2111 and away from the through hole 211a. The first accommodating groove 202 is close to the center side of the through hole 211a. The first accommodating groove 202 includes at least two step grooves, and the cover plate 213 is arranged on one of the at least two step grooves close to the main body 2121; the electrode assembly 22 is arranged in the shell 211 and is electrically connected to the main body 2121 or the connecting part 2122.

[0065] Depending on the shape, the housing 211 can be, but is not limited to, a cylinder, a flat body, a rectangular parallelepiped, or other shapes. Therefore, the housing 211 has multiple walls. For example, referring to FIG3 , when the housing 211 is a rectangular parallelepiped, the housing 211 has small walls at both ends in the first direction X, large walls at both ends in the second direction Y, and top and bottom walls at both ends in the third direction Z. The first wall 2111 can be one of the small wall, the large wall, the top wall, and the bottom wall.

[0066] 6 , the pole 212 includes a main body portion 2121 and a connecting portion 2122 connected to each other. The connecting portion 2122 is passed through the through hole 211a for electrically connecting to external conductive components. The main body portion 2121 is located on the inner side of the first wall 2111 and can play a limiting role, thereby reducing the probability of the connecting portion 2122 being separated from the shell 211.

[0067] The folded portion 201 can limit and fix the connecting portion 2122 to the housing 211. Referring to Figure 6, the folded portion 201 and the main body 2121 can limit the connecting portion 2122 in the third direction Z of the first wall 2111, thereby improving the connection reliability between the pole 212 and the housing 211.

[0068] The first accommodating groove 202 is used to accommodate the cover plate 213. Since the first accommodating groove 202 includes at least two step grooves, when the connecting portion 2122 forms the folding portion 201 by riveting and flanging, due to the influence of the material thickness in the area where the folding portion 201 is located, collapsed edges and large rounded corners will be more likely to form on the step groove close to the folding portion 201, while the step groove close to the main body 2121 is far away from the folding portion 201. Therefore, the probability of forming collapsed edges and large rounded corners is relatively low. By arranging the cover plate 213 on the step groove close to the main body 2121, the probability of a large gap between the cover plate 213 and the corresponding step groove can be reduced, and the probability of explosion points and the like occurring when the cover plate 213 and the pole 212 are welded can be reduced.

[0069] The electrode assembly 22 can refer to the explanation above and will not be repeated here. The electrode assembly 22 can be electrically connected to the main body 2121, or the electrode assembly 22 can be electrically connected to the connecting portion 2122.

[0070] In the above technical solution, the terminal 212 is configured to include a connected main body 2121 and a connecting portion 2122, wherein the connecting portion 2122 has a first receiving groove 202, and the first receiving groove 202 includes at least two stepped grooves. When the connecting portion 2122 of the terminal 212 is folded to form the folded portion 201, the first receiving groove 202 includes at least two stepped grooves, and the probability of the stepped groove near the main body 2121 collapsing or having large rounded corners is relatively low. By positioning the cover plate 213 on the stepped groove near the main body 2121, the probability of a large gap between the cover plate 213 and the corresponding stepped groove can be reduced, thereby reducing the probability of problems such as flash points during welding, which is beneficial for improving the reliability of the battery cell 20. Secondly, because the first receiving groove 202 includes at least two stepped grooves, the riveting die can effectively squeeze the material during the riveting and flanging process, improving the regularity of the welding interface dimensions.

[0071] In some embodiments of the present application, there are at least three step grooves. It can be understood that the number of step grooves can be, but is not limited to, three, four, five, six, and so on.

[0072] There are at least three step grooves, which means that at least one step groove is provided between the step groove close to the folding portion 201 and the step groove close to the main body 2121. When the connecting portion 2122 is partially folded to form the folding portion 201, the step groove in the middle position among the at least three step grooves can form a buffer zone. When the collapsed edge and the large rounded corner are relatively large, under the protection of the step groove in the middle position, the collapsed edge and the large rounded corner can spread to the step groove in the middle position, and are not easy to spread to the step groove close to the main body 2121. That is, the above structure can further reduce the probability of collapsed edge and large rounded corner in the step groove close to the main body 2121, thereby further reducing the probability of a large gap between the cover plate 213 and the step groove.

[0073] In the above technical solution, by setting the number of step grooves to at least three, at least one step groove can be left between the step groove close to the folding portion 201 and the step groove close to the main body 2121, further reducing the probability of collapsed edges and large rounded corners in the step groove close to the main body 2121, and further reducing the probability of explosion points and the like occurring during welding of the cover plate 213 and the connecting portion 2122, and further improving the reliability of the battery cell 20.

[0074] In some embodiments of the present application, referring to Figures 6, 7 and 8, the step groove where the cover plate 213 is located is the first groove 2021, and in the groove depth direction of the first groove 2021, the thickness of the cover plate 213 is less than or equal to the groove depth of the first groove 2021.

[0075] For example, the “groove depth direction of the first groove 2021 ” may refer to the third direction Z in FIG. 6 .

[0076] In the above technical solution, the thickness of the cover plate 213 can be less than the depth of the first groove 2021 in the direction of its depth. In this solution, the outer surface of the cover plate 213 is lower than the outer edge of the first groove 2021. This increases the distance between the outer surface of the cover plate 213 and the collapsed edge and large rounded corners, thereby reducing the impact of the collapsed edge and large rounded corners on the welding of the cover plate 213. The thickness of the cover plate 213 can also be equal to the depth of the first groove 2021 in the direction of its depth. In this solution, the outer surface of the cover plate 213 is flush with the outer edge of the first groove 2021, which not only facilitates welding and improves welding quality, but also improves the aesthetics of the weld between the cover plate 213 and the connecting portion 2122.

[0077] In some embodiments of the present application, referring to FIG. 8 , the groove depth of the first groove 2021 is greater than or equal to 0.6 mm.

[0078] The groove depth of the first groove 2021 may be h1, and h1 may be, but is not limited to, 0.6 mm, 0.62 mm, 0.65 mm, 0.68 mm, 0.7 mm, 0.72 mm, 0.75 mm, 0.78 mm, 0.8 mm, 0.82 mm, 0.85 mm, 0.88 mm, 0.9 mm, 0.92 mm, 0.95 mm, 0.98 mm, 1.0 mm, 1.2 mm, 2.0 mm, and the like.

[0079] Since the cover plate 213 is disposed within the first groove 2021, if the groove depth h1 of the first groove 2021 is less than 0.6 mm, the groove depth of the first groove 2021 is relatively small, the thickness of the cover plate 213 is relatively small, and the depth of the molten pool that can be formed when the cover plate 213 and the connecting portion 2122 are welded (which can refer to the dimension in the third direction Z in FIG6 ) is also relatively small. Therefore, the bonding between the cover plate 213 and the connecting portion 2122 is poor, resulting in relatively poor strength after welding the cover plate 213 and the connecting portion 2122, which affects the reliability of the housing assembly 21. Secondly, referring to FIG6 , the pole 212 is subject to the thrust condition in the third direction Z. The small groove depth of the first groove 2021 will cause the pole 212 to be easily crushed when subjected to the force condition in the third direction Z.

[0080] In the above technical solution, by setting the groove depth of the first groove 2021 to be greater than or equal to 0.6 mm, the first groove 2021 can have an appropriate groove depth, so that the pole 212 has higher strength, and at the same time, the cover plate 213 can have an adapted thickness, thereby improving the strength of the cover plate 213 and the connecting portion 2122 after welding, improving the reliability of the shell assembly 21, and further improving the reliability of the battery cell 20.

[0081] In some embodiments of the present application, referring to FIG. 6 , FIG. 7 and FIG. 8 , the step groove where the cover plate 213 is located is a first groove 2021 , and the first groove 2021 is located on a side of the first wall 2111 away from the main body 2121 .

[0082] It can be understood that the first groove 2021 and the body 2121 are located on both sides of the first wall 2111. For example, referring to FIG6 , the third direction Z may refer to the up-down direction of the housing 211, the first groove 2021 is located on the upper side of the first wall 2111, and the body 2121 is located on the lower side of the first wall 2111.

[0083] In the above technical solution, since the first groove 2021 is connected to the cover plate 213, the position of the first groove 2021 relative to the first wall 2111 affects the position of the cover plate 213 relative to the first wall 2111. By setting the first groove 2021 to be located on the side of the first wall 2111 away from the main body 2121, the cover plate 213 is located on the outside of the first wall 2111 and is relatively far away from the inner side of the shell 211. The probability of the cover plate 213 contacting the electrode assembly 22 is relatively low, which is conducive to the welding of the cover plate 213 and the connecting part 2122 or the main body 2121.

[0084] In some embodiments of the present application, the step groove where the cover plate 213 is located is a first groove 2021, the first groove 2021 has a first groove surface 2021a, and a cover side surface 213a is formed on the peripheral side of the cover plate 213. The cover side surface 213a and the first groove surface 2021a are arranged opposite to each other, and a gap is formed between the cover side surface 213a and the first groove surface 2021a.

[0085] In the above technical solution, the gap formed between the cover side surface 213a and the first groove surface 2021a can be used to place solder, so that the cover plate 213 and the first groove 2021 can be connected by filler welding, which can make the cover plate 213 and the first groove 2021 have a faster welding speed and relatively low requirements for welding assembly, which is conducive to improving welding efficiency.

[0086] In some embodiments of the present application, referring to Figures 7 and 8, the step groove where the cover plate 213 is located is a first groove 2021, the first groove 2021 has a first groove surface 2021a, and a cover side surface 213a is formed on the peripheral side of the cover plate 213. The cover side surface 213a and the first groove surface 2021a are arranged opposite to each other and stop each other.

[0087] In the above technical solution, the gap between the cover side surface 213a and the first groove surface 2021a is relatively small, so that the cover plate 213 and the first groove 2021 can be connected by self-welding, which can make the cover plate 213 and the first groove 2021 have higher connection quality, welding is relatively easy, and the welding seam does not require additional materials, which is conducive to reducing costs.

[0088] In some embodiments of the present application, referring to Figures 5 and 9, the shell 211 includes a shell body 2112 and an end cover 2113, the shell body 2112 has an opening 2112a, the end cover 2113 covers the opening 2112a, and the shell body 2112 or the end cover 2113 forms a first wall 2111.

[0089] In the above technical solution, the shell body 2112 can form a first wall 2111, allowing the shell body 2112 of the battery cell 20 to extend out of the terminal post 212, simplifying the structure of the end cap 2113 and facilitating a lightweight design of the end cap 2113. Since the end cap 2113 is connected to the shell body 2112, the end cap 2113 has a simple structure and is relatively lightweight, which can improve the reliability of the connection between the end cap 2113 and the shell body 2112. The end cap 2113 can also form a first wall 2111, allowing the end cap 2113 of the battery cell 20 to extend out of the terminal post 212. Since the end cap 2113 and the shell body 2112 are separate components, the connection between the terminal post 212 and the first wall 2111 is relatively simple, which can reduce the installation process requirements for the terminal post 212, improve the installation efficiency of the terminal post 212, and reduce costs.

[0090] In some embodiments of the present application, the shell body 2112 can be, but is not limited to, an aluminum shell, a steel shell, etc.

[0091] In some embodiments of the present application, referring to Figures 6, 7 and 8, the connecting portion 2122 has a second accommodating groove 203, the second accommodating groove 203 is connected to the first accommodating groove 202, the main body 2121 is provided with a connecting hole 2121a connected to the second accommodating groove 203, and the electrode assembly 22 includes an active material coating portion 221 and a conductive portion 222 connected to each other, and the conductive portion 222 is passed through the connecting hole 2121a and is electrically connected to the main body 2121 or the connecting portion 2122.

[0092] The conductive portion 222 may be a conductive component connecting the active material coating portion 221 and the terminal 212. For example, the conductive portion 222 may be a tab. The second receiving groove 203, together with the first receiving groove 202, can reduce the weight of the connecting portion 2122, thereby improving the energy density of the battery cell 20. Furthermore, the second receiving groove 203 can accommodate a portion of the conductive portion 222. The conductive portion 222 is electrically connected to the terminal 212 through the connecting hole 2121a, thereby reducing the space occupied by the conductive portion 222 within the housing 211. This saves space within the housing 211 and allows for a larger active material coating portion 221 to be accommodated within the housing 211, further improving the energy density of the battery cell 20.

[0093] The conductive portion 222 may be electrically connected to the main body portion 2121 after passing through the connecting hole 2121 a , and the conductive portion 222 may also be electrically connected to the connecting portion 2122 after passing through the connecting hole 2121 a .

[0094] In the above technical solution, a second accommodating groove 203 connected to the first accommodating groove 202 is provided in the connecting portion 2122, and a connecting hole 2121a connected to the second accommodating groove 203 is provided in the main body 2121, and the conductive portion 222 is passed through the connecting hole 2121a and electrically connected to the main body 2121 or the connecting portion 2122. This not only reduces the weight of the pole 212, but also allows the conductive portion 222 of the electrode assembly 22 to be arranged in the second accommodating groove 203, saving space in the shell 211, thereby providing more space for the active material coating portion 221 of the electrode assembly 22, which is conducive to arranging a larger volume of the active material coating portion 221, thereby improving the energy density of the battery cell 20.

[0095] In some embodiments of the present application, referring to Figure 8, the outermost of the at least two step grooves located on the shell 211 is the second groove 2022. In the groove depth direction of the second groove 2022, the groove depth of the second groove 2022 is T1, and the thickness of the folding portion 201 is T2, wherein T1 / T2≥0.5.

[0096] The “groove depth direction of the second groove 2022 ” may be the third direction Z in FIG. 8 .

[0097] T1 / T2 can be, but is not limited to, 0.5, 0.52, 0.54, 0.56, 0.58, 0.60, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.8, and the like.

[0098] When the partial riveted flange of the connecting portion 2122 forms the folding portion 201, a collapsed edge and a large rounded corner are formed on the side of the folding portion 201 close to the second groove 2022. If T1 / T2 is less than 1 / 2, the groove depth of the second groove 2022 is small, and the probability of the collapsed edge and the large rounded corner spreading out of the second groove 2022 increases, resulting in an increased probability of collapsed edges and large rounded corners in the first groove 2021, which is not conducive to reducing the probability of a large gap between the cover plate 213 and the first groove 2021 when the cover plate 213 is arranged in the first groove 2021.

[0099] In the above technical solution, by setting the ratio between the groove depth T1 of the second groove 2022 and the thickness T2 of the folded portion 201 in the groove depth direction of the second groove 2022 to be greater than or equal to 0.5, the second groove 2022 can have an appropriate groove depth. When the connection portion 2122 is partially riveted and flanged to form the folded portion 201, the second groove 2022 has a larger groove depth to accommodate collapsed edges and large rounded corners, thereby reducing the probability of collapsed edges and large rounded corners spreading out of the second groove 2022, which is beneficial to reducing the probability of a large gap between the cover plate 213 and the first groove 2021, and improving the welding reliability of the cover plate 213 and the first groove 2021.

[0100] In some embodiments of the present application, the thickness T2 of the folded portion 201 may be, but is not limited to, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, etc.

[0101] In some embodiments of the present application, referring to Figure 8, the step groove where the cover plate 213 is located is a first groove 2021, the first groove 2021 has a first groove surface 2021a opposite to the peripheral side surface of the cover plate 213, the connecting portion 2122 has a first side surface 2122a close to the side wall of the through hole 211a and a second side surface 2122b close to the center of the through hole 211a, the distance between the first side surface 2122a and the second side surface 2122b is L1, and the distance between the first groove surface 2021a and the first side surface 2122a is L2, wherein 1 / 2≤L2 / L1≤2 / 3.

[0102] The distance L1 between the first side surface 2122a and the second side surface 2122b may refer to the thickness of the connecting portion 2122, and the distance L2 between the first groove surface 2021a and the first side surface 2122a may refer to the thickness of the remaining portion of the connecting portion 2122 after the first groove 2021 is dug out. L2 / L1 may be, but is not limited to, 1 / 2, 5 / 12, 6 / 12, 7 / 12, 2 / 3, and the like.

[0103] Since the first groove 2021 is relatively close to the folding portion 201, if L2 / L1 is less than 1 / 2, the thickness of the remaining portion of the connecting portion 2122 after removing the first groove 2021 is relatively small, which can easily lead to the connection portion 2122 being relatively weak near the folding portion 201, and a local weak point is likely to appear. Since this position involves the riveting process during the molding process, the size of this position is relatively thin, which will cause the stress to be concentrated in the remaining portion of the connecting portion 2122 after removing the first groove 2021 after riveting. After the pole 212 and the cover plate 213 are welded, the stress release at this position will cause the flange area to warp and crack, and the compression of the seal 25 will be insufficient, resulting in leakage of the battery cell; if L2 / L1 is greater than 2 / 3, the thickness of the remaining part of the connecting portion 2122 after removing the first groove 2021 is relatively large. Correspondingly, the depth of the first groove 2021 along the first direction X is relatively small, and the support for the cover plate 213 is poor, which is not conducive to improving the installation reliability between the cover plate 213 and the first groove 2021.

[0104] In the above technical solution, by setting the ratio of the distance L1 between the first side surface 2122a and the second side surface 2122b of the connecting portion 2122 to the distance L2 between the first groove surface 2021a and the first side surface 2122a within the range of 1 / 2 to 2 / 3, on the one hand, the portion of the connecting portion 2122 close to the folding portion 201 can have an adaptive strength, thereby reducing the probability of local weak points and the probability of cracking caused by stress concentration, thereby improving the reliability of the connecting portion 2122; on the other hand, the first groove 2021 can have an adaptive groove surface to support the cover plate 213, thereby reducing the occurrence of poor installation reliability between the cover plate 213 and the first groove 2021 due to insufficient support, thereby improving the installation reliability between the cover plate 213 and the first groove 2021.

[0105] In some embodiments of the present application, the distance L2 between the first groove surface 2021a and the first side surface 2122a is greater than or equal to 1 mm. It is understood that L2 can be, but is not limited to, 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, etc.

[0106] In some embodiments of the present application, referring to Figure 8, the step groove where the cover plate 213 is located is a first groove 2021, and the first groove 2021 has adjacent first groove surfaces 2021a and second groove surfaces 2021b. The first groove surface 2021a is opposite to the peripheral side surface of the cover plate 213, and the second groove surface 2021b is close to the inner side of the shell 211. A chamfer 2021c is formed between the first groove surface 2021a and the first groove surface 2021b.

[0107] In the above technical solution, the chamfer 2021c can provide a guide for the cover plate 213 to enter the groove, thereby improving the assembly convenience of the cover plate 213. The chamfer 2021c can also facilitate demolding when forming the first groove surface 2021a on the connecting part 2122, which is beneficial to reducing the manufacturing difficulty of the connecting part 2122.

[0108] In some embodiments of the present application, the angle of the chamfer 2021c is 5 degrees to 15 degrees.

[0109] The angle of the chamfer 2021c can be, but is not limited to, 5 degrees, 6 degrees, 7 degrees, 8 degrees, 9 degrees, 10 degrees, 11 degrees, 12 degrees, 13 degrees, 14 degrees, 15 degrees, etc. If the angle of the chamfer 2021c is less than 5 degrees, the angle of the chamfer 2021c is relatively small, the guiding effect is poor, and the mold drafting efficiency is also relatively poor; if the angle of the chamfer 2021c is greater than 15 degrees, the angle of the chamfer 2021c is relatively large, affecting the height of the straight groove surface of the first groove 2021, which is not conducive to the connection between the cover plate 213 and the first groove 2021, and affecting the connection reliability between the cover plate 213 and the first groove 2021.

[0110] In the above technical solution, by setting the angle of the chamfer 2021c within the range of 5 degrees to 15 degrees, the chamfer 2021c is within an appropriate angle range. On the one hand, the chamfer 2021c has a better guiding effect and better demolding efficiency. On the other hand, the straight groove surface of the first groove 2021 can have an appropriate height, so that the cover plate 213 and the first groove 2021 have better bonding and connection reliability.

[0111] In some embodiments of the present application, referring to FIG. 8 , in the groove depth direction of the first groove 2021 , the height of the first groove surface 2021 a is greater than or equal to 0.4 mm.

[0112] The "groove depth direction of the first groove 2021" may refer to the third direction Z in Figure 8. The height of the first groove surface 2021a may be, but is not limited to, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, etc. It can be understood that if the height h2 of the first groove surface 2021a is less than 0.4 mm, that is, the height of the straight groove surface of the first groove 2021 is relatively small, the height of the interface between the cover side surface 213a and the first groove surface 2021a is relatively small, and the straight edge welding area during welding of the cover plate 213 is small, which affects the welding strength between the cover plate 213 and the first groove 2021.

[0113] In the above technical solution, by making the height of the first groove surface 2021a greater than or equal to 0.4 mm in the groove depth direction of the first groove 2021, an effective straight-edge welding area is present between the cover plate 213 and the first groove surface 2021a when welding, thereby making the cover plate 213 and the first groove 2021 have higher welding strength, thereby improving the connection reliability of the cover plate 213 and the first groove 2021.

[0114] In some embodiments of the present application, referring to FIG9 , the battery cell 20 further includes a first insulating member 23, a second insulating member 24, and a sealing member 25. The first insulating member 23 is disposed on the first wall 2111 and is provided with a through hole 23a, which corresponds to the via hole 211a. The connecting portion 2122 is passed through the through hole 23a. The sealing member 25 is sleeved on the connecting portion 2122. The second insulating member 24 is sleeved on the connecting portion 2122 and is located on the side of the sealing member 25 away from the first insulating member 23. The cover plate 213 covers the second insulating member 24. In this technical solution, the folded portion 201 formed by the riveted flange of the connecting portion 2122 abuts against the sealing member 25.

[0115] Optionally, referring to Figure 9, there can be two poles 212, which are respectively the positive pole 2001 and the negative pole 2002, there are two through holes 23 and two vias 211a, and there are two seals 25, one of the two seals 25 is provided on the positive pole 2001 and the other is provided on the negative pole 2002.

[0116] Optionally, the first insulating member 23 and the second insulating member 24 may be, but are not limited to, plastic members.

[0117] In some embodiments of the present application, referring to FIG. 9 , the first wall 2111 is provided with a pressure relief portion 26 . The pressure relief portion 26 can be used to relieve pressure when thermal runaway occurs in the battery cell 20 , thereby improving the reliability of the battery cell 20 .

[0118] Alternatively, the pressure relief portion 26 may be, but is not limited to, an explosion-proof valve, a scored groove, a weakened portion, etc. Referring to FIG9 , illustratively, the first wall 2111 is provided with a pressure relief hole 2111 a , and the pressure relief portion 26 includes a bursting disc 261 and a protective patch 262 . The bursting disc 261 is disposed within the pressure relief hole 2111 a , and the protective patch 262 covers the bursting disc 261 .

[0119] According to the battery cell 20 provided in the embodiment of the present application, the shell body 2112 of the battery cell 20 is an aluminum shell, and a secondary step is added to the pole 212. The welding area is defined in the secondary step area. During the riveting and turning over process, the riveting mold can effectively squeeze the material to ensure that the welding interface size is regular. In the secondary step, the thickness of the first step (first groove 2021) is greater than 1 / 2 of the turning over area thickness, and the thickness of the flanging area is 1.0mm. The positioning position of the secondary step (second groove 2022) is higher than the top upper surface of the aluminum shell, and the thickness of the secondary step area is 0.6mm. The thickness of the straight edge area of ​​the secondary step from the edge of the pole 212 without flanging is 1mm, which ensures the strength of the turning over area, avoids local weak points, and stress concentration causes cracking. The draft angle needs to be increased at the bottom of the secondary step, the draft angle is 5°, and the height of the straight edge area is 0.4mm.

[0120] In a second aspect, referring to FIG. 2 , the present application further provides a battery 100 , comprising the aforementioned battery cell 20 .

[0121] In the above technical solution, the use of the battery cell 20 can reduce the probability of a large gap appearing between the cover plate 213 and the first receiving groove 202 when the terminal 212 is riveted and flanged, thereby reducing the probability of explosion points and the like occurring when the cover plate 213 is welded, so that the battery cell 20 has higher reliability, thereby improving the reliability of the battery 100.

[0122] In a third aspect, the present application further provides an electrical device, comprising the aforementioned battery cell 20 or battery 100 .

[0123] In the above technical solution, the use of the battery cell 20 can reduce the probability of a large gap appearing between the cover plate 213 and the first receiving groove 202 when the terminal 212 is riveted and flanged, and reduce the probability of explosion points and the like occurring when the cover plate 213 is welded, so that the battery cell 20 and the battery 100 have higher reliability, thereby improving the reliability of the electrical device.

[0124] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0125] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, wherein, Comprising: A housing assembly, including a housing, a terminal post, and a cover plate. The housing has a first wall provided with a through hole. The terminal post includes a connected body portion and a connecting portion. The body portion is located inside the first wall, and the connecting portion passes through the through hole. The connecting portion has a folded portion and a first accommodating groove. The folded portion is located outside the first wall and away from the through hole. The first accommodating groove is on the side closer to the center of the through hole. The first accommodating groove includes at least two stepped grooves, and the cover plate is disposed on one of the at least two stepped grooves closer to the body portion; An electrode assembly, which is disposed inside the housing and electrically connected to the body portion or the connecting portion.

2. The battery cell according to claim 1, wherein, The stepped grooves are at least three.

3. The battery cell according to claim 1 or 2, wherein, The stepped groove where the cover plate is located is the first groove. In the depth direction of the first groove, the thickness of the cover plate is less than or equal to the depth of the first groove.

4. The battery cell according to claim 3, wherein, The depth of the first groove is greater than or equal to 0.6 mm.

5. The battery cell according to any one of claims 1 to 4, wherein, The stepped groove where the cover plate is located is the first groove, and the first groove is on the side of the first wall away from the body portion.

6. The battery cell according to any one of claims 1 to 5, wherein, The stepped groove where the cover plate is located is the first groove. The first groove has a first groove surface, and a cover side surface is formed on the periphery of the cover plate. The cover side surface and the first groove surface are oppositely arranged, and a gap is formed between the cover side surface and the first groove surface.

7. The battery cell according to any one of claims 1 to 5, wherein, The stepped groove where the cover plate is located is the first groove. The first groove has a first groove surface, and a cover side surface is formed on the periphery of the cover plate. The cover side surface and the first groove surface are oppositely arranged and abut against each other.

8. The battery cell according to any one of claims 1 to 7, wherein, The housing includes a housing body and an end cover. The housing body has an opening, and the end cover covers the opening. The housing body or the end cover forms the first wall.

9. The battery cell according to any one of claims 1 to 8, wherein, The connecting portion has a second accommodating groove communicating with the first accommodating groove. The body portion is provided with a communication hole communicating with the second accommodating groove. The electrode assembly includes a connected active material coating portion and a conductive portion. The conductive portion passes through the communication hole and is electrically connected to the body portion or the connecting portion.

10. The battery cell according to any one of claims 1 to 9, wherein, Among the at least two stepped grooves, the one located on the outermost side of the housing is the second groove. In the depth direction of the second groove, the depth of the second groove is T1, and the thickness of the folded portion is T2, where T1 / T2≥0.

5.

11. The battery cell according to any one of claims 1 to 10, wherein, The stepped groove where the cover plate is located is the first groove. The first groove has a first groove surface opposite to the peripheral side surface of the cover plate. The connecting portion has a first side surface close to the side wall of the through hole and a second side surface close to the center of the through hole. The distance between the first side surface and the second side surface is L1, and the distance between the first groove surface and the first side surface is L2, where 1 / 2≤L2 / L1≤2 / 3.

12. The battery cell according to any one of claims 1 to 11, wherein, The stepped groove where the cover plate is located is the first groove. The first groove has adjacent first groove surface and second groove surface. The first groove surface is opposite to the peripheral side surface of the cover plate, and the second groove surface is close to the inner side of the housing. A chamfer is formed between the first groove surface and the first groove surface.

13. The battery cell according to claim 12, wherein, The angle of the chamfer is 5 degrees to 15 degrees.

14. The battery cell according to claim 12, wherein, In the depth direction of the first groove, the height of the first groove surface is greater than or equal to 0.4 mm.

15. A battery, wherein, Comprising a battery cell as described in any one of claims 1 to 14.

16. An electrical device, wherein, Comprising a battery cell as described in any one of claims 1 to 14, or a battery as described in claim 15.

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