Battery monomer, battery and electric device

Abstract

The invention discloses a single battery, a battery and a power utilization device, the single battery comprises a shell assembly, the shell assembly comprises a shell, a pole and a cover plate, the shell is provided with a first wall, the first wall is provided with a via hole, the pole comprises a body part and a connecting part which are connected, the body part is located on the inner side of the first wall, the connecting part penetrates through the via hole, the connecting part is provided with a folding part and a first accommodating groove, and the folding part is located in the first accommodating groove; the folding part is located on the outer side of the first wall and far away from the via hole, the first containing groove is close to one side of the center of the via hole and comprises at least two step grooves, and the cover plate is arranged on one of the at least two step grooves close to the body part; and the electrode assembly is arranged in the shell and is electrically connected with the body part or the connecting part. According to the invention, the probability of edge collapse, large fillet and the like between the cover plate and the first accommodating groove can be reduced, the probability of explosion points and the like during welding of the cover plate is reduced, and the reliability of the single battery is improved.

Description

Technical Field

[0001] This application relates to the technical field of batteries, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0002] In recent years, new energy vehicles have witnessed a leapfrog development. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. A battery is composed of a box body and a plurality of battery cells accommodated in the box body. Among them, as a core component of new energy vehicles, the battery has high requirements both in terms of safety and service life. However, during the production and manufacturing process of the battery cells inside the battery, a cover plate is welded to the pole column, and there are reliability problems when the cover plate and the pole column are welded, thus affecting the reliability of the battery cell. Summary of the Invention

[0003] Embodiments of this 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.

[0004] In a first aspect, embodiments of this application provide a battery cell, including: a housing assembly, including a housing, a pole column, and a cover plate. The housing has a first wall, and the first wall is provided with a through hole. The pole column includes a connected body portion and a connection portion. The body portion is located inside the first wall, and the connection portion passes through the through hole. The connection portion has a folded portion and a first receiving groove. The folded portion is located outside the first wall and away from the through hole. The first receiving groove is close to the center of the through hole. The first receiving groove includes at least two stepped grooves. The cover plate is arranged on the stepped groove closer to the body portion among the at least two stepped grooves; an electrode assembly, which is arranged inside the housing and is electrically connected to the body portion or the connection portion.

[0005] In the above technical solution, by setting the pole column to include a connected body portion and a connection portion, the connection portion has a first receiving groove, and the first receiving groove includes at least two stepped grooves. When the connection portion of the pole column is folded to form a folded portion, since the probability of the stepped groove close to the body portion having problems such as edge collapse and large fillets is relatively low, by arranging the cover plate on the stepped groove close to the body portion, the probability of a large gap appearing between the cover plate and the corresponding stepped groove can be reduced, thereby reducing the probability of problems such as explosion points during welding, which is beneficial to improving the reliability of the battery cell. Secondly, since the first receiving groove includes at least two stepped grooves, during the riveting and flanging process, the riveting die can effectively extrude the material, improving the regularity of the welding interface size.

[0006] In some embodiments of the present application, there are at least three stepped grooves. In this technical solution, by setting the stepped grooves to at least three, there can be at least one stepped groove between the stepped groove near the folding part and the stepped groove near the body part, further reducing the probability of the stepped groove near the body part having edge collapse and large fillets, and further reducing the probability of situations such as explosion points occurring during the welding of the cover plate and the connecting part, and further improving the reliability of the battery cell.

[0007] In some embodiments of the present application, 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.

[0008] In the above technical solution, in the depth direction of the first groove, the thickness of the cover plate can be less than the depth of the first groove, and the outer surface of the cover plate is lower than the outer edge of the first groove, which can increase the distance between the outer surface of the cover plate and the edge collapse and large fillets, and reduce the influence of the edge collapse and large fillets on the welding of the cover plate. In the depth direction of the first groove, 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. On the one hand, it is beneficial to the formation of the welding mark and improves the welding quality. On the other hand, it is beneficial to improve the welding aesthetics of the cover plate and the connecting part.

[0009] In some embodiments of the present application, the depth of the first groove is greater than or equal to 0.6 mm. In this technical solution, by setting the depth of the first groove to be greater than or equal to 0.6 mm, the first groove can have an appropriate depth, enabling the pole post to have a higher strength, and at the same time enabling the cover plate to have an appropriate thickness, thereby improving the strength after the cover plate and the connecting part are welded, improving the reliability of the housing assembly, and further improving the reliability of the battery cell.

[0010] In some embodiments of the present application, the stepped groove where the cover plate is located is the first groove, and the first groove is located on the side of the first wall away from the body part. In this technical solution, since 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 setting the first groove to be located on the side of the first wall away from the body part, the cover plate is located outside the first wall and is relatively far from the inside of the housing, and the probability of the cover plate contacting the electrode assembly is relatively low, which is beneficial to the welding of the cover plate and the connecting part or the body part.

[0011] In some embodiments of the present application, 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 circumferential side of the cover plate. The cover side surface and the first groove surface are arranged opposite to each other, and a gap is 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, enabling the cover plate and the first groove to be connected by the filler welding method, which can enable the cover plate and the first groove to have a relatively fast welding speed and relatively low requirements for welding assembly, and is beneficial to improving the welding efficiency.

[0012] In some embodiments of the present application, 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 circumferential side of the cover plate. The cover side surface and the first groove surface are oppositely arranged and abutted against each other. In this technical solution, the gap between the cover side surface and the first groove surface is relatively small, so that the cover plate and the first groove can be connected by autogenous welding, which can make the connection quality between the cover plate and the first groove relatively high, the welding is relatively easy, and no additional material is required for the weld seam, which is beneficial to cost reduction.

[0013] In some embodiments of the present application, the housing includes a housing body and an end cover. The housing body has an open mouth, and the end cover is disposed on the open mouth. The housing body or the end cover forms a first wall.

[0014] In the above technical solution, the housing body can form the first wall, so that the pole post comes out of the housing body of the battery cell. Adopting this solution can simplify the structure of the end cover, which is beneficial to the lightweight design of the end cover. Since the end cover is connected to the housing body, the structure of the end cover is simple and the weight is relatively light, which can improve the connection reliability between the end cover and the housing body. The end cover can also form the first wall, so that the pole post comes out of the end cover of the battery cell. Adopting this solution, since the end cover and the housing body are separate components, the connection between the pole post and the first wall is relatively simple, which can reduce the installation process requirements for the pole post, improve the installation efficiency of the pole post, and reduce costs.

[0015] In some embodiments of the present application, the connecting portion has a second receiving groove, the second receiving groove communicates with the first receiving groove, the body portion is provided with a communication hole communicating with the second receiving groove, and 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.

[0016] In the above technical solution, by providing a second receiving groove communicating with the first receiving groove in the connecting portion, and a communication hole communicating with the second receiving groove in the body portion, the conductive portion passes through the communication hole and is electrically connected to the body portion or the connecting portion, which can not only reduce the weight of the pole post, but also arrange the conductive portion of the electrode assembly in the second receiving groove, saving the space inside the housing, thereby providing more space for the active material coating portion of the electrode assembly, which is beneficial to arranging a larger volume of the active material coating portion, and further improving the energy density of the battery cell.

[0017] In some embodiments of the present application, the outermost one of at least two stepped grooves in the housing 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 folding portion is T2, where T1 / T2≥0.5.

[0018] In the above technical solution, by setting the ratio between the groove depth T1 of the second groove and the thickness T2 of the folding part to be greater than or equal to 0.5 in the groove depth direction of the second groove, the second groove can have an appropriate groove depth. When a part of the connecting part is riveted and flanged to form a folding part, the second groove has a larger groove depth to accommodate the collapse edge and large fillet, reducing the probability of the collapse edge and large fillet 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 between the cover plate and the first groove.

[0019] In some embodiments of the present application, 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 part 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.

[0020] In the above technical solution, by setting the ratio between the distance L1 between the first side surface and the second side surface of the connecting part and the distance L2 between the first groove surface and the first side surface within the range of 1 / 2 to 2 / 3, on the one hand, it can make the part of the connecting part close to the folding part have appropriate strength, reduce the probability of local weak points, and reduce the probability of cracking caused by stress concentration, improving the reliability of the connecting part. On the other hand, it can make the first groove have an appropriate groove surface to support the cover plate, reducing the occurrence of poor installation reliability due to insufficient support between the cover plate and the first groove, which is beneficial to improving the installation reliability between the cover plate and the first groove.

[0021] In some embodiments of the present application, 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 inside of the housing. A chamfer is formed between the first groove surface and the first groove surface. In this technical solution, the chamfer can provide a guiding function for the cover plate to enter the groove, improving the assembly convenience of the cover plate, and the chamfer can also facilitate the demolding when forming the first groove surface on the connecting part, which is beneficial to reducing the manufacturing difficulty of the connecting part.

[0022] In some embodiments of the present application, the angle of the chamfer is 5 degrees to 15 degrees. In this technical solution, by setting the angle of the chamfer within the range of 5 degrees to 15 degrees, the chamfer is within an appropriate angle range. On the one hand, the chamfer has a good guiding function and good demolding convenience. 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 good bonding and connection reliability.

[0023] In some embodiments of the present application, in the groove depth direction of the first groove, the height of the first groove surface is greater than or equal to 0.4 mm. In this technical solution, by making the height of the first groove surface greater than or equal to 0.4 mm in the groove depth direction of the first groove, there is an effective straight-edge welding area between the cover plate and the first groove surface during cover plate welding, thereby enabling the cover plate and the first groove to have a relatively high welding strength and improving the connection reliability between the cover plate and the first groove.

[0024] In a second aspect, the present application also provides a battery, including the battery cell described above.

[0025] In the above technical solution, using this battery cell can reduce the probability of a large gap appearing between the cover plate and the first receiving groove during pole riveting and flanging, and reduce the probability of situations such as explosion points occurring during cover plate welding, making the battery cell have relatively high reliability, thereby improving the reliability of the battery.

[0026] In a third aspect, the present application also provides an electrical device, including the battery cell or the battery described above.

[0027] In the above technical solution, using this battery cell can reduce the probability of a large gap appearing between the cover plate and the first receiving groove during pole riveting and flanging, and reduce the probability of situations such as explosion points occurring during cover plate welding, making the battery cell and the battery have relatively high reliability, thereby improving the reliability of the electrical device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] To more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings required for use in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, without creative efforts, other related drawings can also be obtained based on these drawings.

[0029] Figure 1 Structural schematic diagram of a vehicle provided by some embodiments of the present application;

[0030] Figure 2 Exploded view of the structure of a battery provided by some embodiments of the present application;

[0031] Figure 3 Three-dimensional structural schematic diagram of a battery cell provided by some embodiments of the present application;

[0032] Figure 4 Top view of a battery cell provided by some embodiments of the present application;

[0033] Figure 5 For Figure 4 Schematic diagram taken along line A-A;

[0034] Figure 6is Figure 5 Partial enlarged view of part I of Figure 5 ;

[0035] Figure 7 is Figure 5 Partial enlarged view of part II of Figure 5 ;

[0036] Figure 8 Schematic diagram of the partial structure of a battery cell provided by some embodiments of the present application;

[0037] Figure 9 Explosion decomposition diagram of a battery cell provided by some embodiments of the present application.

[0038] Icon:

[0039] 1000, vehicle; 100, battery; 10, box body; 11, first box body; 12, second box body; 20, battery cell; 21, housing assembly; 211, housing; 2111, first wall; 2111a, pressure relief hole; 2112, shell body; 2112a, open end; 2113, end cover; 211a, through hole; 212, pole; 2121, body part; 2121a, communication hole; 2122, connection part; 2122a, first side; 2122b, second side; 201, folding part; 202, first receiving groove; 2021, first groove; 2021a, first groove surface; 2021b, second groove surface; 2021c, chamfer; 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 part; 222, conductive part; 23, first insulating part; 24, second insulating part; 25, seal; 26, pressure relief part; 261, explosion-proof film; 262, protection patch; 200, controller; 300, motor; X, first direction; Y, second direction; Z, third direction. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0041] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application pertains; the terms used in the description of the application in this application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description and claims of this application and the above drawings are intended to cover non-exclusive inclusion. The terms "first", "second", etc. in the description and claims of this application or the above drawings are used to distinguish different objects and not to describe a specific order or primary-secondary relationship.

[0042] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of this application. The phrase appearing at various positions in the description does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0043] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "coupled", "attached" shall be construed in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0044] The term "and / or" in this application is merely a description of the relationship between associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally represents an "or" relationship between the associated objects before and after.

[0045] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, in different embodiments, the detailed description of the same components is omitted. It should be understood that the thickness, length, width, etc. of various components shown in the drawings of the embodiments of this application, as well as the overall thickness, length, width, etc. of the integrated device, are only for illustrative purposes and should not constitute any limitation to this application.

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

[0047] In this application, the battery cell may include a lithium-ion secondary battery, a lithium-ion primary battery, a lithium-sulfur battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc., and the embodiments of this application do not limit this. The battery cell can be in the shape of a cylinder, a flat body, a cuboid, or other shapes, and the embodiments of this application do not limit this either. Generally, the battery cells are divided into three types according to the packaging method: cylindrical battery cells, square battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this either.

[0048] The battery mentioned 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 mentioned in this application may include a battery module or a battery pack, etc. Generally, the battery includes a box for encapsulating one or more battery cells or multiple battery modules. The box can prevent liquids or other foreign objects from affecting the charging or discharging of the battery cells.

[0049] The battery cell includes a housing, an electrode assembly, and an electrolyte. The housing is used to accommodate the electrode assembly and the electrolyte. The electrode assembly is composed of a positive electrode tab, a negative electrode tab, and a separator. The battery cell mainly operates by the movement of metal ions between the positive electrode tab and the negative electrode tab. The positive electrode tab includes a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive current collector. The positive current collector without the coated positive active material layer protrudes from the positive current collector with the coated positive active material layer. The positive current collector without the coated positive active material layer serves as the positive electrode ear. Taking a lithium-ion battery as an example, the material of the positive current collector can be aluminum, and the positive active material can be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate, etc. The negative electrode tab includes 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 without the coated negative active material layer protrudes from the negative current collector with the coated negative active material layer. The negative current collector without the coated negative active material layer serves as the negative electrode ear. The material of the negative current collector can be copper, and the negative active material can be carbon or silicon, etc. In order to ensure that a large current can pass through without fusing, the number of positive electrode ears is multiple and stacked together, and the number of negative electrode ears is multiple and stacked together.

[0050] The material of the separator can be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly can be a wound structure or a stacked structure, and the embodiments of this application are not limited thereto.

[0051] In recent years, new energy vehicles have witnessed a leapfrog development. In the field of electric vehicles, the power battery, as the power source of the electric vehicle, plays an irreplaceable and important role. The battery consists of a box body and a plurality of battery cells accommodated in the box body. Among them, the battery, as a core component of new energy vehicles, has high requirements both in terms of safety and service life. However, during the production and manufacturing process of the battery cells inside the battery, a cover plate is welded to the pole column, but there are prone to reliability problems when the cover plate is welded to the pole column, thus affecting the reliability of the battery cells.

[0052] The inventor found that in the structure of the battery cell, the pole column is provided with a receiving groove. During the manufacturing of the battery cell, the pole column passes through a through-hole in the housing, and a partial peripheral wall of the pole column forming the receiving groove can be fixed to the housing by means of riveting and flanging. At this time, the flanged part in the pole column forms a folded part. The cover plate can be arranged in the receiving groove and welded to the inner side of the folded part to be fixed on the pole column. The cover plate can be used for electrically connecting an external conductor. However, during this process, due to the influence of the material thickness in the area where the folded part is located on the pole column, the folded part of the folded part close to the receiving groove is prone to problems such as edge collapse and large fillets. This will cause a relatively large gap when assembling the riveting position between the pole column and the cover plate during welding, and it is easy to cause problems such as explosion points during welding, thus affecting the reliability of the battery cell.

[0053] Based on the above considerations, in order to solve the problem that it is easy to have problems such as explosion points when the pole column and the cover plate are welded due to the edge collapse, large fillets, etc. in the folded part of the pole column, the inventor designed a battery cell, which includes a housing assembly and an electrode assembly. The housing assembly includes a housing, a pole column, and a cover plate. The housing has a first wall, and the first wall is provided with a through-hole. The pole column includes a connected body part and a connecting part. The body part is located inside the first wall, and the connecting part passes through the through-hole. The connecting part has a folded part and a first receiving groove. The folded part is located outside the first wall and away from the through-hole. The first receiving groove is close to the center of the through-hole. The first receiving groove includes at least two stepped grooves. The cover plate is arranged on the stepped groove closer to the body part among the at least two stepped grooves; the electrode assembly is arranged inside the housing and is electrically connected to the body part or the connecting part.

[0054] In the battery cell with this structure, by setting the pole column to include a connected body part and a connecting part, the connecting part has a first receiving groove, and the first receiving groove includes at least two stepped grooves. When the connecting part of the pole column is folded to form a folded part, since the probability of edge collapse and large fillets in the stepped groove close to the body part is relatively low, by arranging the cover plate on the stepped groove close to the body part, the probability of a large gap appearing between the cover plate and the corresponding stepped 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.

[0055] 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 of the electrical device can be composed of battery cells, batteries, etc. disclosed in the present application.

[0056] The embodiments of the present application provide an electrical device using a battery as a power source. The electrical device can be, but is not limited to, a mobile phone, a tablet computer, a laptop computer, an electric toy, an electric tool, a battery car, an electric vehicle, a ship, a spacecraft, etc. The electric toy can include a stationary or mobile electric toy, for example, a game console, an electric vehicle toy, an electric ship toy, an electric aircraft toy, etc. The spacecraft can include an airplane, a rocket, a space shuttle, a spaceship, etc.

[0057] For the convenience of description in the following embodiments, a vehicle 1000, which is an electrical device in an embodiment of the present application, is taken as an example for illustration. Please refer to Figure 1 , Figure 1 which is a schematic structural diagram of the vehicle 1000 provided in some embodiments of the present application. The vehicle 1000 can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, an extended-range electric vehicle, etc. A battery 100 is disposed inside the vehicle 1000. The battery 100 can be disposed at the bottom, the head, or the tail of the vehicle 1000. The battery 100 can be used for power supply of the vehicle 1000. For example, the battery 100 can be used as an operating power source of the vehicle 1000. The vehicle 1000 can further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to supply power to the motor 300. For example, it is used for the working power requirements during the start, navigation, and driving of the vehicle 1000.

[0058] In some embodiments of the present application, the battery 100 can not only be used as an operating power source of the vehicle 1000, but also be used as a driving power source of the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0059] Please refer to Figure 2 , Figure 2Exploded view of the structure of battery 100 provided by some embodiments of the present application. The battery 100 includes a box body 10 and a plurality of battery cells 20, and the battery cells 20 are configured to be accommodated within the box body 10. Among them, the box body 10 is used to provide an assembly space for the battery cells 20, and the box body 10 can adopt various structures. In some embodiments, the box body 10 may include a first box body 11 and a second box body 12, the first box body 11 and the second box body 12 are covered with each other, and the first box body 11 and the second box body 12 jointly define an assembly space for accommodating the battery cells 20. The second box body 12 may be a hollow structure with one end open, and the first box body 11 may be a plate-like structure. The first box body 11 is covered on the open side of the second box body 12 so that the first box body 11 and the second box body 12 jointly define an assembly space; the first box body 11 and the second box body 12 may also both be hollow structures with one side open, and the open side of the first box body 11 is covered on the open side of the second box body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be of various shapes, such as a cylinder, a cuboid, etc.

[0060] In the battery 100, the plurality of battery cells 20 can be connected in series, in parallel, or in a hybrid connection. A hybrid connection means that there are both series and parallel connections among the plurality of battery cells 20. The plurality of battery cells 20 can be directly connected in series, in parallel, or in a hybrid connection together, and then the whole formed by the plurality of battery cells 20 is accommodated within the box body 10; of course, the battery 100 can also be that the plurality of battery cells 20 are first connected in series, in parallel, or in a hybrid connection to form a battery module form, and then the plurality of battery modules are connected in series, in parallel, or in a hybrid connection to form a whole and are accommodated within the box body 10. The battery 100 may further include other structures. For example, the battery 100 may further include a busbar component for realizing the electrical connection among the plurality of battery cells 20.

[0061] Please refer to Figure 2 , Figure 2 Exploded view of the structure of battery 100 provided by some embodiments of the present application. The battery 100 includes multiple rows of battery cells 20, and the multiple rows of battery cells 20 can be arranged along the length direction of the box body 10, and each row of battery cells 20 includes a plurality of battery cells 20 arranged along the width direction of the box body 10; or, the multiple rows of battery cells 20 can be arranged along the width direction of the box body 10, and each row of battery cells 20 includes a plurality of battery cells 20 arranged along the length direction of the box body 10. Among them, 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 in the shape of a cylinder, a flat body, a cuboid, or other shapes, etc. Exemplarily, in Figure 2 ,the shape of the battery cell 20 is a cuboid.

[0062] According to some embodiments of the present application, refer to Figures 3 to 6 ,Figure 3 A battery cell 20 provided for some embodiments of the present application includes a housing assembly 21 and an electrode assembly 22. The housing assembly 21 includes a housing 211, a pole column 212, and a cover plate 213. The housing 211 has a first wall 2111, and a through hole 211a is provided on the first wall 2111. The pole column 212 includes a connected body portion 2121 and a connection portion 2122. The body portion 2121 is located inside the first wall 2111, and the connection portion 2122 passes through the through hole 211a. The connection portion 2122 has a folded portion 201 and a first receiving groove 202. The folded portion 201 is located outside the first wall 2111 and away from the through hole 211a. The first receiving groove 202 is close to one side of the center of the through hole 211a. The first receiving groove 202 includes at least two stepped grooves, and the cover plate 213 is disposed on one of the at least two stepped grooves close to the body portion 2121; the electrode assembly 22 is disposed inside the housing 211 and is electrically connected to the body portion 2121 or the connection portion 2122.

[0063] According to different shapes, the housing 211 can be, but is not limited to, a cylinder, a flat body, a cuboid, or other shapes, etc. Therefore, the housing 211 has a plurality of wall portions. Exemplarily, referring to Figure 3 , when the housing 211 is a cuboid, the housing 211 has small face walls at both ends in the first direction X, large face walls at both ends in the second direction Y, a top wall and a bottom wall at both ends in the third direction Z. The first wall 2111 can be one of the small face wall, the large face wall, the top wall, and the bottom wall.

[0064] Referring to Figure 6 , the pole column 212 includes a connected body portion 2121 and a connection portion 2122. The connection portion 2122 passes through the through hole 211a and is used to electrically connect an external conductive component. The body portion 2121 is located inside the first wall 2111 and can play a limiting role to reduce the probability of the connection portion 2122 detaching from the housing 211.

[0065] The folded portion 201 can play a limiting and fixing role to fix the connection portion 2122 on the housing 211. Referring to Figure 6 , the folded portion 201 and the body portion 2121 can play a limiting role in the third direction Z of the first wall 2111 for the connection portion 2122, improving the connection reliability between the pole column 212 and the housing 211.

[0066] The first receiving groove 202 is used to receive the cover plate 213. Since the first receiving groove 202 includes at least two stepped 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, the edge collapse and large fillets are more likely to form on the stepped groove close to the folding portion 201, while the stepped groove close to the main body portion 2121 is far from the folding portion 201. Therefore, the probability of forming the edge collapse and large fillets is relatively low. By arranging the cover plate 213 on the stepped groove close to the main body portion 2121, the probability of a large gap appearing between the cover plate 213 and the corresponding stepped groove can be reduced, and the probability of problems such as explosion points occurring during the welding of the cover plate 213 and the terminal 212 can be reduced.

[0067] The electrode assembly 22 can refer to the previous explanation and will not be elaborated here. The electrode assembly 22 can be electrically connected to the main body portion 2121, or the electrode assembly 22 is electrically connected to the connecting portion 2122.

[0068] In the above technical solution, by setting the terminal 212 to include a connected main body portion 2121 and a connecting portion 2122, 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 folding portion 201, since the first receiving groove 202 includes at least two stepped grooves, the probability of the stepped groove close to the main body portion 2121 having problems such as edge collapse and large fillets is relatively low. By arranging the cover plate 213 on the stepped groove close to the main body portion 2121, the probability of a large gap appearing between the cover plate 213 and the corresponding stepped groove can be reduced, thereby reducing the probability of problems such as explosion points occurring during welding, which is beneficial to improving the reliability of the battery cell 20. Secondly, since the first receiving groove 202 includes at least two stepped grooves, during the riveting and flanging process, the riveting die can effectively extrude the material, improving the regularity of the welding interface size.

[0069] In some embodiments of the present application, the stepped groove is at least three. It can be understood that the stepped groove can be, but is not limited to, three, four, five, six, etc.

[0070] The stepped groove is at least three, indicating that at least one stepped groove is also provided between the stepped groove close to the folding portion 201 and the stepped groove close to the main body portion 2121. When the connecting portion 2122 is partially folded to form the folding portion 201, the stepped groove in the middle position among the at least three stepped grooves can form a buffer zone. When the edge collapse and large fillets are relatively large, under the protection of the stepped groove in the middle position, the edge collapse and large fillets can spread to the stepped groove in the middle position and are not easily spread to the stepped groove close to the main body portion 2121. That is, adopting the above structure can further reduce the probability of the stepped groove close to the main body portion 2121 having edge collapse and large fillets, thereby further reducing the probability of a large gap appearing between the cover plate 213 and this stepped groove.

[0071] In the above 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 201 and the step groove near the body portion 2121, further reducing the probability of the step groove near the body portion 2121 having edge collapse and large fillets, and thus further reducing the probability of situations such as explosion points occurring during the welding of the cover plate 213 and the connecting portion 2122, and further improving the reliability of the battery cell 20.

[0072] In some embodiments of the present application, referring to Figure 6 、 Figure 7 and Figure 8 , the step groove where the cover plate 213 is located is the first groove 2021, and in the depth direction of the first groove 2021, the thickness of the cover plate 213 is less than or equal to the depth of the first groove 2021.

[0073] Exemplarily, the "depth direction of the first groove 2021" may refer to Figure 6 the third direction Z in

[0074] In the above technical solution, in the depth direction of the first groove 2021, the thickness of the cover plate 213 may be less than the depth of the first groove 2021. In this case, the outer surface of the cover plate 213 is lower than the outer edge of the first groove 2021, which can increase the distance between the outer surface of the cover plate 213 and the edge collapse and large fillets, and reduce the influence of the edge collapse and large fillets on the welding of the cover plate 213. In the depth direction of the first groove 2021, the thickness of the cover plate 213 may also be equal to the depth of the first groove 2021. In this case, the outer surface of the cover plate 213 is flush with the outer edge of the first groove 2021. On the one hand, it is beneficial to the formation of the welding mark and improves the welding quality. On the other hand, it is beneficial to improving the welding aesthetics of the cover plate 213 and the connecting portion 2122.

[0075] In some embodiments of the present application, referring to Figure 8 , the depth of the first groove 2021 is greater than or equal to 0.6 mm.

[0076] The 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, etc.

[0077] Since the cover plate 213 is disposed in 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 is welded to the connecting portion 2122 (which can refer to Figure 6 the dimension in the third direction Z) is also relatively small. Therefore, the bonding property between the cover plate 213 and the connecting portion 2122 is poor, resulting in relatively poor strength after the cover plate 213 and the connecting portion 2122 are welded, which will affect the reliability of the housing assembly 21. Secondly, referring to Figure 6 , the pole column 212 is involved in the thrust working condition in the third direction Z. When the groove depth of the first groove 2021 is small, the pole column 212 is likely to be crushed under the force working condition in the third direction Z.

[0078] 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 column 212 has a high strength, and at the same time, the cover plate 213 can have an appropriate thickness, thereby improving the strength after the cover plate 213 and the connecting portion 2122 are welded, improving the reliability of the housing assembly 21, and further improving the reliability of the battery cell 20.

[0079] In some embodiments of the present application, referring to Figure 6 , Figure 7 and Figure 8 , the stepped groove where the cover plate 213 is located is the first groove 2021, and the first groove 2021 is located on the side of the first wall 2111 away from the body portion 2121.

[0080] It can be understood that the first groove 2021 and the body portion 2121 are located on both sides of the first wall 2111. Exemplarily, referring to Figure 6 , the third direction Z can refer to the up and down direction of the housing 211. The first groove 2021 is located on the upper side of the first wall 2111, and the body portion 2121 is located on the lower side of the first wall 2111.

[0081] 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 body portion 2121, the cover plate 213 is located outside the first wall 2111 and is relatively far from the inside of the housing 211. The probability of the cover plate 213 contacting the electrode assembly 22 is relatively low, which is beneficial to the welding of the cover plate 213 and the connecting portion 2122 or the body portion 2121.

[0082] In some embodiments of the present application, the stepped groove where the cover plate 213 is located is the first groove 2021. The first groove 2021 has a first groove surface 2021a. A cover side surface 213a is formed on the circumferential side of the cover plate 213. The cover side surface 213a and the first groove surface 2021a are oppositely arranged, and a gap is formed between the cover side surface 213a and the first groove surface 2021a.

[0083] 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 a filler welding method, which can enable the cover plate 213 and the first groove 2021 to have a relatively fast welding speed, and the requirements for welding and assembly are relatively low, which is beneficial to improving the welding efficiency.

[0084] In some embodiments of the present application, referring to Figure 7 and Figure 8 , the stepped groove where the cover plate 213 is located is the first groove 2021. The first groove 2021 has a first groove surface 2021a. A cover side surface 213a is formed on the circumferential side of the cover plate 213. The cover side surface 213a and the first groove surface 2021a are oppositely arranged and abut against each other.

[0085] 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 a self-fusion welding method, which can enable the cover plate 213 and the first groove 2021 to have a relatively high connection quality, the welding is relatively easy, and the weld joint does not require additional materials, which is beneficial to reducing costs.

[0086] In some embodiments of the present application, referring to Figure 5 and Figure 9 , the housing 211 includes a housing body 2112 and an end cover 2113. The housing body 2112 has an open end 2112a. The end cover 2113 is covered on the open end 2112a. The housing body 2112 or the end cover 2113 forms a first wall 2111.

[0087] In the above technical solution, the housing body 2112 can form the first wall 2111, so that the housing body 2112 of the battery cell 20 leads out the pole column 212, simplifies the structure of the end cover 2113, is beneficial to the lightweight design of the end cover 2113. Since the end cover 2113 and the housing body 2112 are connected, the structure of the end cover 2113 is simple and the weight is light, which can improve the connection reliability between the end cover 2113 and the housing body 2112. The end cover 2113 can also form the first wall 2111, so that the end cover 2113 of the battery cell 20 leads out the pole column 212. Since the end cover 2113 and the housing body 2112 are separate components, the connection between the pole column 212 and the first wall 2111 is relatively simple, which can reduce the installation process requirements for the pole column 212, improve the installation efficiency of the pole column 212, and reduce costs.

[0088] In some embodiments of the present application, the housing body 2112 may be, but is not limited to, an aluminum housing, a steel housing, etc.

[0089] In some embodiments of the present application, referring to Figure 6 , Figure 7 and Figure 8 , the connecting portion 2122 has a second receiving groove 203. The second receiving groove 203 communicates with the first receiving groove 202. The body portion 2121 is provided with a communication hole 2121a communicating with the second receiving groove 203. The electrode assembly 22 includes a connected active material coating portion 221 and a conductive portion 222. The conductive portion 222 passes through the communication hole 2121a and is electrically connected to the body portion 2121 or the connecting portion 2122.

[0090] The conductive portion 222 may refer to a conductive component connecting the active material coating portion 221 and the pole 212. For example, the conductive portion 222 may be a tab. On the one hand, the second receiving groove 203 and the first receiving groove 202 together can play a role in weight reduction, which can reduce the weight of the connecting portion 2122 and is beneficial to improving the energy density of the battery cell 20. On the other hand, the second receiving groove 203 can play a role in accommodating part of the conductive portion 222. The conductive portion 222 passes through the communication hole 2121a and is electrically connected to the pole 212, which is beneficial to reducing the space occupied by the conductive portion 222 in the housing 211, saving the space inside the housing 211, and enabling a larger-sized active material coating portion 221 to be arranged inside the housing 211, further improving the energy density of the battery cell 20.

[0091] Among them, the conductive portion 222 may be electrically connected to the body portion 2121 after passing through the communication hole 2121a, or the conductive portion 222 may be electrically connected to the connecting portion 2122 after passing through the communication hole 2121a.

[0092] In the above technical solution, by providing the second receiving groove 203 communicating with the first receiving groove 202 in the connecting portion 2122, and the communication hole 2121a communicating with the second receiving groove 203 in the body portion 2121, the conductive portion 222 passes through the communication hole 2121a and is electrically connected to the body portion 2121 or the connecting portion 2122, which can not only reduce the weight of the pole 212, but also arrange the conductive portion 222 of the electrode assembly 22 in the second receiving groove 203, saving the space inside the housing 211, thereby providing more space for the active material coating portion 221 of the electrode assembly 22, being beneficial to arranging a larger volume of the active material coating portion 221, and further improving the energy density of the battery cell 20.

[0093] In some embodiments of the present application, referring to Figure 8, among the at least two stepped grooves, the outermost one located in the housing 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, where T1 / T2 ≥ 0.5.

[0094] The "groove depth direction of the second groove 2022" can be Figure 8 the third direction Z in

[0095] 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, etc.

[0096] When a part of the connecting portion 2122 is riveted and flanged to form the folding portion 201, a collapse edge and a large fillet 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 collapse edge and the large fillet spreading out of the second groove 2022 increases, resulting in an increase in the probability of the collapse edge and the large fillet appearing 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.

[0097] 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 folding portion 201 to be greater than or equal to 0.5 in the groove depth direction of the second groove 2022, the second groove 2022 can have an appropriate groove depth. When a part of the connecting portion 2122 is riveted and flanged to form the folding portion 201, the second groove 2022 has a larger groove depth to accommodate the collapse edge and the large fillet, reducing the probability of the collapse edge and the large fillet 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 between the cover plate 213 and the first groove 2021.

[0098] In some embodiments of the present application, the thickness T2 of the folding portion 201 can 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.

[0099] In some embodiments of the present application, referring to Figure 8, the stepped groove where the cover plate 213 is located is the first groove 2021. The first groove 2021 has a first groove surface 2021a opposite to the circumferential side surface of the cover plate 213. The connecting portion 2122 has a first side surface 2122a close to the side wall of the via hole 211a and a second side surface 2122b close to the center of the via 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, where 1 / 2 ≤ L2 / L1 ≤ 2 / 3.

[0100] The distance L1 between the first side surface 2122a and the second side surface 2122b of the connecting portion 2122 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 can be, but not limited to, 1 / 2, 5 / 12, 6 / 12, 7 / 12, 2 / 3, etc.

[0101] 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 easily leads to relatively weak strength of the portion of the connecting portion 2122 close to the folding portion 201 and prone to local weak points. Since this position involves a riveting process during the forming process and the dimension here is relatively thin, it will cause stress to concentrate at the remaining portion of the connecting portion 2122 after removing the first groove 2021. After the pole 212 and the cover plate 213 are welded, the stress release at this position will cause the flanging area to warp and crack, and the compression amount of the seal 25 is insufficient, resulting in liquid leakage of the battery cell; if L2 / L1 is greater than 2 / 3, the thickness of the remaining portion 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 relatively poor, which is not conducive to improving the installation reliability between the cover plate 213 and the first groove 2021.

[0102] In the above technical solution, by setting the ratio between the distance L1 between the first side surface 2122a and the second side surface 2122b of the connecting portion 2122 and 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, it can make the portion of the connecting portion 2122 close to the folding portion 201 have appropriate strength, reduce the probability of local weak points, and reduce the probability of cracking caused by stress concentration, improving the reliability of the connecting portion 2122; on the other hand, it can make the first groove 2021 have an appropriate groove surface to support the cover plate 213, reducing the situation of poor installation reliability between the cover plate 213 and the first groove 2021 due to insufficient support, which is conducive to improving the installation reliability between the cover plate 213 and the first groove 2021.

[0103] 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 can be 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.

[0104] In some embodiments of the present application, referring to Figure 8 , the stepped groove where the cover plate 213 is located is the first groove 2021. The first groove 2021 has adjacent first groove surfaces 2021a and second groove surfaces 2021b. The first groove surface 2021a faces the circumferential side surface of the cover plate 213, and the second groove surface 2021b is close to the inner side of the housing 211. A chamfer 2021c is formed between the first groove surface 2021a and the first groove surface 2021b.

[0105] In the above technical solution, the chamfer 2021c can provide a guiding function for the cover plate 213 to enter the groove, improve the assembly convenience of the cover plate 213, and the chamfer 2021c can also facilitate the demolding when the first groove surface 2021a is formed on the connecting portion 2122, which is beneficial to reducing the manufacturing difficulty of the connecting portion 2122.

[0106] In some embodiments of the present application, the angle of the chamfer 2021c is 5 degrees to 15 degrees.

[0107] 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, and the guiding function it can play is relatively poor, and the demolding convenience 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, which affects the height of the straight groove surface of the first groove 2021, is not conducive to the combination of the cover plate 213 and the first groove 2021, and affects the connection reliability between the cover plate 213 and the first groove 2021.

[0108] 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 a suitable angle range. On the one hand, the chamfer 2021c has a good guiding function and good demolding convenience, and on the other hand, it can also make the straight groove surface of the first groove 2021 have a suitable height, so that the cover plate 213 and the first groove 2021 have good combination and connection reliability.

[0109] In some embodiments of the present application, referring to Figure 8 , in the groove depth direction of the first groove 2021, the height of the first groove surface 2021a is greater than or equal to 0.4 mm.

[0110] "The groove depth direction of the first groove 2021" can refer toFigure 8 In the third direction Z, the height of the first groove surface 2021a can 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 joint surface between the cover side surface 213a and the first groove surface 2021a is relatively small, and the straight-edge welding area during the welding of the cover plate 213 is small, which affects the welding strength between the cover plate 213 and the first groove 2021.

[0111] 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, there is an effective straight-edge welding area between the cover plate 213 and the first groove surface 2021a during welding, thereby enabling the cover plate 213 and the first groove 2021 to have a high welding strength and improving the connection reliability between the cover plate 213 and the first groove 2021.

[0112] In some embodiments of the present application, referring to Figure 9 , 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 provided on the first wall 2111. The first insulating member 23 is provided with a through hole 23a. The through hole 23 corresponds to the through hole 211a. The connecting portion 2122 passes 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 folding portion 201 formed by riveting and flanging the connecting portion 2122 abuts against the sealing member 25.

[0113] Optionally, referring to Figure 9 , there may be two pole posts 212, which are respectively a positive pole post 2001 and a negative pole post 2002. Both the through hole 23 and the through hole 211a are two. There are two sealing members 25. One of the two sealing members 25 is provided on the positive pole post 2001, and the other is provided on the negative pole post 2002.

[0114] Optionally, the first insulating member 23 and the second insulating member 24 can be, but are not limited to, plastic parts. -

[0115] In some embodiments of the present application, referring to Figure 9 , the first wall 2111 is provided with a pressure relief portion 26. The pressure relief portion 26 can be used for pressure relief when the battery cell 20 undergoes thermal runaway, improving the reliability of the battery cell 20.

[0116] Optionally, the pressure relief portion 26 can be, but is not limited to, an explosion-proof valve, a scoring groove, a weak portion, etc. Referring to Figure 9, Exemplarily, the first wall 2111 is provided with a pressure relief hole 2111a. The pressure relief portion 26 includes an explosion-proof sheet 261 and a protective patch 262. The explosion-proof sheet 261 is disposed in the pressure relief hole 2111a, and the protective patch 262 covers the explosion-proof sheet 261.

[0117] According to the battery cell 20 provided by the embodiment of the present application, the housing 2112 of the battery cell 20 is an aluminum shell. A secondary step is added to the pole post 212, and the welding area is defined in the secondary step area. During the riveting and flanging process, the riveting die can effectively extrude the material to ensure the regular size of the welding interface. In the secondary step, the thickness of the first step (the first groove 2021) is greater than 1 / 2 of the thickness of the flanging area, and the thickness of the flanging area is 1.0 mm. The positioning position of the secondary step (the second groove 2022) is higher than the upper surface of the top of the aluminum shell, and the thickness of the secondary step area is 0.6 mm. The distance from the edge of the secondary step to the non-flanged straight edge area of the pole post 212 is 1 mm, which ensures the strength of the flanging area and avoids local weak points and stress concentration leading to cracking. A draft angle of 5° needs to be added to the bottom of the secondary step, and the height of the straight edge area is 0.4 mm.

[0118] In a second aspect, referring to Figure 2 , the present application further provides a battery 100, including the battery cell 20 described above.

[0119] In the above technical solution, using the battery cell 20 can reduce the probability of a large gap appearing between the cover plate 213 and the first receiving groove 202 during the riveting and flanging of the pole post 212, thereby reducing the probability of situations such as explosion points during the welding of the cover plate 213, making the battery cell 20 have high reliability, and thus improving the reliability of the battery 100.

[0120] In a third aspect, the present application further provides an electrical device, including the battery cell 20 or the battery 100 described above.

[0121] In the above technical solution, using the battery cell 20 can reduce the probability of a large gap appearing between the cover plate 213 and the first receiving groove 202 during the riveting and flanging of the pole post 212, reduce the probability of situations such as explosion points during the welding of the cover plate 213, make the battery cell 20 and the battery 100 have high reliability, and thus improve the reliability of the electrical device.

[0122] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other.

[0123] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, the present application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A battery cell, characterized in that, Comprising: A housing assembly, including a housing, a pole post, and a cover plate. The housing has a first wall provided with a through hole. The pole 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 receiving groove. The folded portion is located outside the first wall and away from the through hole. The first receiving groove is on the side closer to the center of the through hole. The first receiving 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, characterized in that, 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, characterized in that, The stepped groove where the cover plate is located is the first groove, and the first groove is located 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, characterized in that, The stepped groove where the cover plate is located is the first groove. The first groove has a first groove surface. The circumferential side of the cover plate forms a cover side surface. The cover side surface and the first groove surface are oppositely arranged, and there is a gap between the cover side surface and the first groove surface.

7. The battery cell according to any one of claims 1 to 5, characterized in that, The stepped groove where the cover plate is located is the first groove. The first groove has a first groove surface. The circumferential side of the cover plate forms a cover side surface. The cover side surface and the first groove surface are oppositely arranged and are in mutual abutment.

8. The battery cell according to any one of claims 1 to 7, characterized in that, 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, characterized in that, The connecting portion has a second receiving groove communicating with the first receiving groove. The body portion is provided with a communication hole communicating with the second receiving 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, characterized in that, 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, characterized in that, The stepped groove where the cover plate is located is the first groove. The first groove has a first groove surface opposite to the circumferential 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, characterized in that, The stepped groove where the cover plate is located is the first groove. The first groove has an adjacent first groove surface and a second groove surface. The first groove surface is opposite to the circumferential 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, characterized in that, Comprising a battery cell as described in any one of claims 1 to 14.

16. An electrical device, characterized in that, 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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