Battery cell, battery device, and electric device

Abstract

The application discloses a battery monomer, a battery device and a power utilization device. The battery monomer comprises a shell, an electrode assembly, an end cover assembly and an electrode terminal, the shell is provided with an opening; the electrode assembly is arranged in the interior of the shell, the electrode assembly comprises a main body part and a tab led out from the end of the main body part; the end cover assembly is arranged at the opening of the shell, the end cover assembly comprises an end cover and an insulating piece, the insulating piece is arranged on the side of the end cover facing the electrode assembly, the end cover is provided with an electrode leading-out hole; the electrode terminal is at least partially accommodated in the electrode leading-out hole, the electrode terminal is provided with a welding surface welded with the tab, and the distance between the welding surface and the insulating piece in the first direction is H, and H satisfies: H >= 2.1 mm; wherein the first direction is the height direction of the battery monomer. The application improves the reliability of the battery monomer.

Description

Technical Field

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

[0002] Battery cells are widely used in electronic devices such as mobile phones, laptops, electric vehicles, electric cars, electric airplanes, electric ships, electric toy cars, electric toy ships, electric toy airplanes, and power tools. Battery cells can include nickel-cadmium battery cells, nickel-metal hydride battery cells, lithium-ion battery cells, and rechargeable alkaline zinc-manganese battery cells, among others.

[0003] In the development of battery technology, improving the reliability of individual battery cells is a key research direction. Utility Model Content

[0004] This application provides a battery cell, a battery device, and an electrical device that can improve the reliability of the battery cell.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a housing, an electrode assembly, an end cap assembly, and electrode terminals. The housing has an opening. The electrode assembly is disposed inside the housing and includes a main body and tabs extending from the end of the main body. The end cap assembly covers the opening of the housing and includes an end cap and an insulating member. The insulating member is disposed on the side of the end cap facing the electrode assembly, and the end cap has an electrode lead-out hole. The electrode terminals are at least partially accommodated in the electrode lead-out hole and have a welding surface for welding to the tabs. Along a first direction, the distance between the welding surface and the insulating member is H, where H satisfies: H≥2.1mm; wherein, the first direction is the height direction of the battery cell.

[0006] In the above solution, the electrode terminals are directly welded to the tabs, eliminating the need for adapter components. Without increasing the width of the tabs protruding relative to the main body, the distance between the welding surface of the electrode terminals and the tabs and the insulating component is increased. This not only increases the space between the electrode assembly and the end cap, providing storage space for the gas generated by the battery cell during operation and reducing the internal pressure of the battery cell, but also prevents laser welding from burning the insulating component to a certain extent, reducing damage to the insulating component and thus improving the reliability of the battery cell.

[0007] In some embodiments, H satisfies: 5mm ≤ H ≤ 8mm.

[0008] In the above scheme, by further limiting the distance between the welding surface of the electrode terminal and the tab and the insulating component, it is possible not only to further reduce the internal pressure of the battery cell and further reduce the damage to the insulating component, but also to ensure the energy density of the battery cell to a certain extent.

[0009] In some embodiments, the welding surface is located on the side of the electrode terminal facing the electrode assembly.

[0010] In the above scheme, by setting the welding surface on the side of the electrode terminal facing the electrode assembly, it is not only convenient to weld the electrode terminal to the tab, but also to increase the distance between the welding surface and the insulating component in the limited space, without affecting the energy density of the battery cell.

[0011] In some embodiments, the electrode terminal includes a connecting portion and a terminal body, the terminal body protruding from the connecting portion and at least partially accommodated in the electrode lead-out hole, the projection of the terminal body along a first direction being located within the projection of the connecting portion along the first direction, and the welding surface being located in the connecting portion.

[0012] In the above solution, the connection part can increase the welding surface area to a larger extent, which increases the welding area between the electrode terminal and the electrode tab, thereby improving the connection stability between the electrode terminal and the electrode tab.

[0013] In some embodiments, the battery cell further includes a seal disposed around the terminal body, at least a portion of which is clamped between the end cap and the connector.

[0014] In the above solution, the sealing element can enhance the sealing effect between the end cap and the electrode terminal, reduce the probability of leakage of the battery cell, and further improve the reliability of the battery cell.

[0015] In some embodiments, along the first direction, the distance between the welding surface and the seal is greater than the distance between the welding surface and the insulating element.

[0016] The above scheme ensures a large gap between the welding surface and the seal to a certain extent, thereby preventing laser welding from ablating the seal, reducing damage to the seal, and further improving the reliability of the battery cell.

[0017] In some embodiments, the connecting portion includes a side wall and a bottom wall. The side wall is connected to the terminal body and is arranged around the bottom wall in a circumferential manner. The bottom wall is located on the side of the side wall away from the terminal body, and the welding surface is located on the bottom wall.

[0018] In the above solution, by directly thickening the connecting part, there is no need to increase the width of the tab protruding relative to the main body, thus increasing the space between the electrode assembly and the end cap. The connecting part is formed by the side wall and the bottom wall, which simplifies the process and facilitates the fabrication of the end cap.

[0019] In some embodiments, the connecting portion includes an extension portion and a bending portion. The extension portion is connected to the terminal body, and the bending portion is disposed on the side of the extension portion away from the terminal body. The welding surface is located on the bending portion. The extension directions of the extension portion and the bending portion are intersecting.

[0020] In the above solution, by adding a bent section, the overall thickness of the connection is increased, eliminating the need to increase the width of the tab protruding relative to the main body, thus increasing the space between the electrode assembly and the end cap. The connection is formed by extending sections and bent sections with different extension directions, creating a gap on the side of the bent section facing the insulator. This increases the difficulty of transferring the high-temperature heat from laser welding to the insulator, further increasing the difficulty of laser welding ablation of the insulator and further improving the reliability of the battery cell.

[0021] In some embodiments, the bending sub-section bends from the extension sub-section toward the interior of the battery cell.

[0022] In the above scheme, by bending the bending section into the inside of the battery cell, the utilization rate of the internal space of the battery cell can be increased, and the energy density of the battery cell can be increased.

[0023] In some embodiments, the bending sub-section bends outward from the extension sub-section toward the outside of the battery cell.

[0024] In the above solution, by bending the bent part outwards towards the battery cell, the distance between the tabs of the two electrode assemblies is increased when the two electrode assemblies are welded to the same electrode terminal, which can reduce the risk of short circuit between the two electrode assemblies.

[0025] In some embodiments, the bent portion extends along a second direction, which is the thickness direction of the battery cell.

[0026] In the above solution, by extending the bent portion along the thickness direction of the battery cell, it is easier to weld it to the tab of the electrode assembly, thereby increasing the welding area between the electrode terminal and the tab.

[0027] In some embodiments, the extension sub-part extends along a first direction.

[0028] In the above scheme, by extending the extension sub-part along the height direction of the battery cell, interference between the electrode terminals and other structures inside the battery cell can be prevented to a certain extent.

[0029] In some embodiments, there are two extension sub-parts and two bending sub-parts. The two extension sub-parts are respectively disposed on opposite sides of the terminal body, and the two bending sub-parts are connected to the two extension sub-parts in a one-to-one correspondence.

[0030] In the above scheme, by connecting the two bent sub-parts and the two extended sub-parts one-to-one, it is possible to weld one electrode terminal to the tabs of two electrode assemblies at the same time, thereby improving the energy density of the battery cell.

[0031] In some embodiments, the welding surface is a flat surface, which increases the contact area between the electrode terminal and the electrode tab during welding and improves the welding effect.

[0032] Secondly, embodiments of this application also provide a battery device, including a battery cell of any of the above embodiments.

[0033] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device, which is used to provide electrical energy.

[0034] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the drawings without creative effort.

[0036] Figure 1 This is a schematic diagram of a vehicle according to some embodiments of this application;

[0037] Figure 2 This is a schematic diagram of the battery structure according to some embodiments of this application;

[0038] Figure 3 for Figure 2 The diagram shows the structure of the battery module.

[0039] Figure 4 This is an exploded structural diagram of a battery cell according to some embodiments of this application;

[0040] Figure 5 This is a side cross-sectional view of a battery cell according to some embodiments of this application;

[0041] Figure 6 This is a front cross-sectional view of a battery cell according to some embodiments of this application;

[0042] Figure 7 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application;

[0043] Figure 8 This is a schematic diagram of the assembly of the end cap assembly and the electrode assembly according to some embodiments of this application;

[0044] Figure 9 This is a schematic diagram of the end cap assembly according to other embodiments of this application;

[0045] Figure 10This is a schematic diagram of the assembly of the end cap assembly and the electrode assembly according to other embodiments of this application;

[0046] Figure 11 This is a schematic diagram of the assembly of the end cap assembly and the bent electrode tab in some other embodiments of this application;

[0047] Figure 12 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application;

[0048] Figure 13 This is a schematic diagram of the assembly of the end cap assembly and the electrode assembly according to some embodiments of this application;

[0049] Figure 14 This is a schematic diagram of the assembly of the end cap assembly and the bent electrode tab according to some embodiments of this application.

[0050] The accompanying drawings are not drawn to scale.

[0051] Explanation of icon numbers:

[0052] 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 30, Housing; 10, Top Cover; 400, Battery Module; 20, Battery Cell; 22, Housing; 21, End Cap Assembly; 211, End Cap; 212, Insulator; 24, Outer Shell; 241, Electrode Lead-out Hole; 26, Electrode Terminal; 23, Electrode Assembly; 231, Main Body; 232, Electrode Tab; 261, Connecting Part; 262, Terminal Body; 263, Welding Surface; 264, Side Wall; 265, Bottom Wall; 266, Extension Sub-part; 267, Bending Sub-part; 27, Sealing Component; X, First Direction; Y, Second Direction. Detailed Implementation

[0053] The embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The detailed description of the following embodiments and the accompanying drawings are used to illustrate the principles of this application by way of example, but should not be used to limit the scope of this application, that is, this application is not limited to the described embodiments.

[0054] In the description of this application, it should be noted that, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," and "outer," etc., indicating orientation or positional relationships, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. "Vertical" is not vertical in the strict sense, but within the allowable tolerance range. "Parallel" is not parallel in the strict sense, but within the allowable tolerance range.

[0055] In this application, the reference to "embodiment" means that a specific feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described in this application can be combined with other embodiments.

[0056] The directional terms used in the following description refer to the directions shown in the figures and are not intended to limit the specific structure of this application. It should also be noted in the description of this application that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0057] In this application, the battery cell may include a lithium-ion secondary battery cell, a lithium-ion primary battery cell, a lithium-sulfur battery cell, a sodium-lithium-ion battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, etc., and the embodiments of this application are not limited thereto. The battery cell may be cylindrical, flat, cuboid, or other shapes, etc., and the embodiments of this application are not limited thereto. Battery cells are generally classified into three types according to their packaging method: cylindrical battery cells, cuboid / square battery cells, and pouch battery cells, and the embodiments of this application are not limited thereto.

[0058] The battery device mentioned in the embodiments of this application may include one or more battery cell assemblies for providing voltage and capacity. A battery cell assembly may include multiple battery cells, which are connected in series, parallel, or mixed connections via a busbar.

[0059] In some embodiments, a battery cell assembly is typically formed by arranging multiple battery cells; as an example, a battery cell assembly can be a battery module, which is formed by arranging and fixing multiple battery cells into a single module. As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0060] In some embodiments, the battery device may be a battery pack, which includes a housing and one or more individual battery cell assemblies housed within the housing.

[0061] As an example, the battery cell assembly can be a battery module, which can be housed in a housing by fixing the battery module in the housing.

[0062] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0063] This application provides an electrical device that uses a battery as a power source. The electrical device can be, but is not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0064] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0065] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. New energy vehicles can be pure electric vehicles, hybrid electric vehicles, or range-extended electric vehicles, etc. A battery device 100 is installed inside the vehicle 1000, and the battery device 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery device 100 can be used to power the vehicle 1000; for example, the battery device 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300. The controller 200 is used to control the battery device 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during starting, navigation, and driving.

[0066] In some embodiments of this application, the battery device 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0067] Please refer to Figure 2 , Figure 2 This is an exploded view of the apparatus provided in some embodiments of this application. The battery device 100 includes a battery housing and battery cells 20. In some embodiments, the battery housing may include a top cover 10 and a housing 30, with the top cover 10 and housing 30 covering each other, and the top cover 10 and housing 30 together defining a receiving cavity for receiving the battery cells 20. The housing 30 may be a hollow structure with one end open, and the top cover 10 may be a plate-like structure, with the top cover 10 covering the open side of the housing 30 so that the top cover 10 and housing 30 together define the receiving cavity; the top cover 10 and housing 30 may also be hollow structures with one side open, with the open side of the top cover 10 covering the open side of the housing 30. Of course, the battery housing formed by the top cover 10 and housing 30 can be of various shapes, such as a cylinder, a cuboid, etc.

[0068] Figure 3 This is a schematic diagram of the structure of a battery module according to some embodiments of this application. In the battery device 100, there can be multiple battery cells 20, which can be connected in series, parallel, or in a mixed manner. A mixed connection means that multiple battery cells 20 are connected in both series and parallel. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the whole assembly of multiple battery cells 20 is housed in a housing. Of course, the battery device 100 can also be in the form of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module 400, and then multiple battery modules 400 are connected in series, parallel, or in a mixed manner to form a whole and housed in a housing. The battery device 100 may also include other structures. For example, the battery device 100 may also include a busbar component for realizing the electrical connection between multiple battery cells 20.

[0069] Each battery cell 20 can be a secondary battery cell or a primary battery cell; it can also be a lithium-sulfur battery cell, a sodium-ion battery cell, or a magnesium-ion battery cell, but is not limited to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0070] Please refer to Figure 4 , Figure 4 This is an exploded structural diagram of a battery cell provided in some embodiments of this application. A battery cell 20 refers to the smallest unit that makes up a battery. The battery cell 20 includes a casing, electrode assembly 23, and other functional components.

[0071] The outer casing includes an end cap 211 and a housing 22. The end cap 211 is a component that covers the opening of the housing 22 to isolate the internal environment of the battery cell 20 from the external environment. The shape of the end cap 211 can be adapted to the shape of the housing 22 to fit it. Optionally, the end cap 211 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the end cap 211 is less prone to deformation under pressure and impact, allowing the battery cell 20 to have higher structural strength and improved safety performance. Functional components such as electrode terminals 26 can be provided on the end cap 211. The electrode terminals 26 can be used for electrical connection with the electrode assembly 23 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the end cap 211 can also be provided with a pressure relief mechanism for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 211 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this application embodiment does not impose any special limitations on this. In some embodiments, an insulating element may be provided on the inner side of the end cap 211. The insulating element can be used to isolate the electrical connection components in the housing 22 from the end cap 211 to reduce the risk of short circuit. For example, the insulating element can be plastic, rubber, etc.

[0072] Currently, during the use of battery cells, the electrolyte is gradually consumed, and a certain amount of gas is generated, which increases the internal pressure of the battery cell. At the same time, in order to meet the energy density of the battery cell, the reserved space between the end cap and the electrode assembly is limited, which compresses the internal space of the battery cell, resulting in increased internal pressure. The pressure relief mechanism opens prematurely, reducing the service life of the battery cell. Moreover, when the tabs are directly welded to the electrode terminals, due to the limited space, laser welding is prone to burning the insulation of the end cap, reducing the reliability of the battery cell.

[0073] To address the aforementioned technical problems, this application provides a battery cell comprising a housing, an electrode assembly, an end cap assembly, and electrode terminals. The housing has an opening. The electrode assembly is disposed inside the housing and includes a main body and tabs extending from the end of the main body. The end cap assembly covers the opening of the housing and includes an end cap and an insulating member. The insulating member is disposed on the side of the end cap facing the electrode assembly, and the end cap has an electrode lead-out hole. The electrode terminals are at least partially accommodated in the electrode lead-out hole and have a welding surface for welding to the tabs. Along a first direction, the distance between the welding surface and the insulating member is H, where H ≥ 2.1 mm. The first direction is the height direction of the battery cell.

[0074] In the above solution, the electrode terminals are directly welded to the tabs, eliminating the need for adapter components. Without increasing the width of the tabs protruding relative to the main body, the distance between the welding surface of the electrode terminals and the tabs and the insulating component is increased. This not only increases the space between the electrode assembly and the end cap, providing storage space for the gas generated by the battery cell during operation and reducing the internal pressure of the battery cell, but also prevents laser welding from burning the insulating component to a certain extent, reducing damage to the insulating component and thus improving the reliability of the battery cell.

[0075] Figure 5 This is a side cross-sectional view of a battery cell according to some embodiments of this application. Figure 5 As shown, in a first aspect, embodiments of this application provide a battery cell 20, which includes a housing 22, an electrode assembly 23, an end cap assembly 21, and an electrode terminal 26. The housing 22 has an opening. The electrode assembly 23 is disposed inside the housing 22 and includes a main body 231 and a tab 232 extending from the end of the main body 231. The end cap assembly 21 covers the opening of the housing 22 and includes an end cap 211 and an insulating member 212. The insulating member 212 is disposed on the side of the end cap 211 facing the electrode assembly 23, and the end cap 211 has an electrode lead-out hole 241. The electrode terminal 26 is at least partially accommodated in the electrode lead-out hole 241 and has a welding surface 263 for welding to the tab 232. Along a first direction X, the distance between the welding surface 263 and the insulating member 212 is H, where H ≥ 2.1 mm. The first direction X is the height direction of the battery cell 20.

[0076] The housing 22 and end cap 211 are connected to form a shell 24, the interior of which houses the electrode assembly 23. The housing 22 can be a metal part made of materials such as aluminum or steel. An insulating member 212 is located on the side of the end cap 211 facing the electrode assembly 23, and the insulating member 212 can prevent short circuits to a certain extent. The electrode lead-out hole 241 passes through the end cap 211 and the insulating member 212 in sequence. The welding surface 263 of the electrode tab 232 and the electrode terminal 26 can be directly welded by laser welding without the need for an adapter. The electrical energy of the electrode assembly 23 is transferred to the outside in sequence through the electrode tab 232 and the electrode terminal 26.

[0077] It should be noted that the distance between the welding surface 263 and the insulating component 212 refers to the vertical distance between them. If the welding surface 263 or the insulating component 212 is not planar, multiple measurement points can be taken on the welding surface 263 to measure the distance between these points and the insulating component 212. The average value of these distance values ​​is then calculated as the distance H between the welding surface 263 and the insulating component 212.

[0078] The distance H between the weld surface 263 and the insulating component 212 can be measured using either a direct measurement method or an optical measurement method. Direct measurement can be performed using calipers or a micrometer. For example, align the caliper's measuring jaws perpendicular to the measuring surface and read the value displayed on the caliper; this is the distance between the weld surface 263 and the insulating component 212. Alternatively, gently touch the micrometer's measuring head to the weld surface 263 and the insulating component 212, rotate the micrometer knob until the measuring head is in close contact with the measuring surface, and read the value on the micrometer. Optical measurement can be performed using a laser rangefinder. A laser rangefinder is a non-contact measuring tool that can be used to measure the distance between the weld surface 263 and the insulating component 212. When the laser rangefinder is aimed at the weld surface 263 and the insulating component 212, it emits a laser beam. The laser beam reflects back after encountering the object's surface, and the laser rangefinder calculates the distance between the object's surfaces by measuring the time it takes for the laser to travel back and forth.

[0079] The distance H between the welding surface 263 and the insulating component 212 along the height direction of the battery cell 20 satisfies: H ≥ 2.1 mm. H can be any value greater than or equal to 2.1 mm. For example, H can be 2.1 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, etc. In this embodiment, the distance H between the welding surface 263 and the insulating component 212 is larger than that of conventional battery cells 20; that is, this embodiment increases the distance between the welding surface 263 and the insulating component 212. If the space between the electrode assembly 23 and the end cap 211 is increased by increasing the width of the tab 232 protruding relative to the main body 231, for example, by setting the width of the tab 232 protruding relative to the main body 231 to be greater than or equal to 30 mm, it cannot meet the manufacturability problem. However, in this embodiment, by increasing the distance between the welding surface 263 and the insulating component 212, it is not necessary to increase the width of the tab 232 protruding relative to the main body 231.

[0080] In the above scheme, the electrode terminal 26 is directly welded to the tab 232, eliminating the need for an adapter. Without increasing the width of the tab 232 protruding relative to the main body 231, the distance between the welding surface 263 of the electrode terminal 26 and the tab 232 and the insulating component 212 is increased. This not only increases the space between the electrode assembly 23 and the end cap 211, providing storage space for the gas generated by the battery cell 20 during operation and reducing the internal pressure of the battery cell 20, but also prevents the laser welding from burning the insulating component 212 to a certain extent, reducing damage to the insulating component 212, thereby improving the reliability of the battery cell 20.

[0081] In some embodiments, H satisfies: 5mm ≤ H ≤ 8mm.

[0082] Wherein, H can be any value from 5mm to 8mm. For example, H can be 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.6mm, 6.7mm, 6.8mm, 7.9mm, etc.

[0083] In the above scheme, by further limiting the distance between the welding surface 263 where the electrode terminal 26 is welded to the tab 232 and the insulating component 212, not only can the internal pressure of the battery cell 20 be further reduced and the damage to the insulating component 212 be further reduced, but the energy density of the battery cell 20 can also be guaranteed to a certain extent.

[0084] In some embodiments, the welding surface 263 is located on the side of the electrode terminal 26 facing the electrode assembly 23.

[0085] Taking the end cap 211 located at the top of the housing 22 as an example, the welding surface 263 is located at the bottom of the electrode terminal 26. The bottom of the electrode terminal 26 is directly laser welded to the tab 232, and the tab 232 is bent relative to the main body 231.

[0086] In the above scheme, by setting the welding surface 263 on the side of the electrode terminal 26 facing the electrode assembly 23, it is not only convenient to weld the electrode terminal 26 to the tab 232, but also to increase the distance between the welding surface 263 and the insulating component 212 in the limited space, without affecting the energy density of the battery cell 20.

[0087] Figure 6 This is a front cross-sectional view of a battery cell in some embodiments of this application.

[0088] like Figure 6 As shown, in some embodiments, the electrode terminal 26 includes a connecting portion 261 and a terminal body 262. The terminal body 262 protrudes from the connecting portion 261 and is at least partially accommodated in the electrode lead-out hole 241. The projection of the terminal body 262 along the first direction X is located within the projection of the connecting portion 261 along the first direction X, and the welding surface 263 is located in the connecting portion 261.

[0089] The connecting portion 261 of the electrode terminal 26 can be rectangular, square, circular, or other shapes. The terminal body 262 can be cylindrical, cubic, cuboid, or other irregular shapes. The tab 232 and the connecting portion 261 of the electrode terminal 26 facing the electrode assembly 23 can be directly welded by laser welding, without the need for an adapter. The electrical energy of the electrode assembly 23 is transmitted to the outside sequentially through the tab 232, the connecting portion 261, and the terminal body 262.

[0090] The projection of the terminal body 262 along the first direction X is located within the projection of the connecting portion 261 along the first direction X, that is, the cross-sectional area of ​​the connecting portion 261 is larger than the cross-sectional area of ​​the terminal body 262. The welding surface 263 can be located on the bottom surface of the connecting portion 261, that is, the bottom of the connecting portion 261 is welded to the tab 232.

[0091] In the above solution, the connecting part 261 can increase the welding surface 263 to a larger area, that is, it can increase the welding surface area 263 between the electrode terminal 26 and the tab 232, thereby improving the connection stability between the electrode terminal 26 and the tab 232.

[0092] In some embodiments, the battery cell 20 further includes a seal 27 disposed around the terminal body 262, at least a portion of the seal 27 being held between the end cap 211 and the connection portion 261.

[0093] The seal 27 may be a sealing ring surrounding the outer periphery of the terminal body 262; or the seal 27 may include a plurality of sealing blocks spaced apart along the outer periphery of the terminal body 262.

[0094] The seal 27 can be made of compressible materials such as rubber or foam. The seal 27 is disposed in a compressed state between the end cap 211 and the connecting part 261.

[0095] In the above solution, the seal 27 can enhance the sealing effect between the end cap 211 and the electrode terminal 26, reduce the probability of leakage of the battery cell 20, and further improve the reliability of the battery cell 20.

[0096] In some embodiments, along the first direction X, the distance between the welding surface 263 and the seal 27 is greater than the distance between the welding surface 263 and the insulator 212.

[0097] The method for measuring the distance between the welding surface 263 and the seal 27 can refer to the method for measuring the distance between the welding surface 263 and the insulating part 212.

[0098] In the above scheme, a large gap is ensured between the welding surface 263 and the seal 27 to a certain extent, thereby preventing laser welding from burning the seal 27, reducing damage to the seal 27, and further improving the reliability of the battery cell 20.

[0099] Figure 7 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application; Figure 8 This is a schematic diagram of the assembly of the end cap assembly and the electrode assembly according to some embodiments of this application.

[0100] Please refer to the following: Figure 7 and Figure 8In some embodiments, the connecting portion 261 includes a side wall 264 and a bottom wall 265. The side wall 264 is connected to the terminal body 262 and is arranged around the bottom wall 265 in a circumferential manner. The bottom wall 265 is disposed on the side of the side wall 264 away from the terminal body 262, and the welding surface 263 is located on the bottom wall 265.

[0101] The connecting part 261 can be in the shape of a cuboid, cube, or cylinder, or it can be set as a stepped shape, with each step corresponding to a different thickness. The connecting part 261 can be solid or hollow.

[0102] The side panel 264 is connected to the terminal body 262 and is arranged circumferentially along the bottom wall 265, providing mechanical support and protection and improving the connection reliability between the electrode terminal 26 and the end cap 211. At the same time, the side panel 264 also plays a certain role in sealing, reducing the risk of electrolyte leakage.

[0103] The bottom wall 265 is located on the side of the side enclosure 264 away from the terminal body 262, and the welding surface 263 is located on the bottom wall 265. That is, the tab 232 is directly welded to the bottom wall 265 of the connecting part 261, so that the current can be transmitted from the tab 232 to the electrode terminal 26.

[0104] In the above solution, by directly thickening the connecting portion 261, it is not necessary to increase the width of the tab 232 protruding relative to the main body 231, thereby increasing the space between the electrode assembly 23 and the end cap 211. The connecting portion 261 is formed by the side wall 264 and the bottom wall 265, which simplifies the process and facilitates the fabrication of the end cap 211. Moreover, the thickened electrode terminal 26 can directly support the electrode assembly 23, preventing the electrode assembly 23 from shaking to a certain extent.

[0105] Figure 9 This is a schematic diagram of the end cap assembly according to other embodiments of this application; Figure 10 This is a schematic diagram of the assembly of the end cap assembly and the electrode assembly according to other embodiments of this application; Figure 11 This is a schematic diagram of the assembly of the end cap assembly and the bent electrode tab in some other embodiments of this application.

[0106] Please refer to the following: Figures 9-11 In some embodiments, the connecting portion 261 includes an extension portion 266 and a bending portion 267. The extension portion 266 is connected to the terminal body 262, and the bending portion 267 is disposed on the side of the extension portion 266 away from the terminal body 262. The welding surface 263 is located on the bending portion 267. The extension directions of the extension portion 266 and the bending portion 267 are intersected.

[0107] The extension portion 266 is connected to the terminal body 262, mainly serving as a connection and transition. The presence of the extension portion 266 allows the electrode terminal 26 to smoothly extend from the terminal body 262 portion 231 to a suitable position for welding with the tab 232. The extension portion 266 can extend along the height direction of the battery cell 20, or it can extend in a direction inclined relative to the height direction of the battery cell 20.

[0108] The bent portion 267 is located on the side of the extension portion 266 opposite to the terminal body 262, and the welding surface 263 is located on the bent portion 267, i.e., the tab 232 is welded to the bent portion 267. The tab 232 can be welded to the side of the bent portion 267 opposite to the extension portion 266. The extension directions of the bent portion 267 and the extension portion 266 are intersecting, i.e., the bent portion 267 bends relative to the extension portion 266 in other directions. By bending, the original single extension direction of the connecting portion 261 is changed, resulting in an additional increase in the dimension of the connecting portion 261 perpendicular to the extension direction, thereby increasing the overall thickness of the connecting portion 261.

[0109] The extending direction of the bending sub-section 267 and the extending sub-section 266 can be perpendicular to each other, or the included angle between them can be acute or obtuse. The bending sub-section 267 can be bent from the extending sub-section 266 towards the interior or exterior of the battery cell 20.

[0110] In the above solution, by setting the bending sub-section 267, the overall thickness of the connecting section 261 is increased, eliminating the need to increase the width of the tab 232 protruding relative to the main body 231, thereby increasing the space between the electrode assembly 23 and the end cap 211. The connecting section 261 is formed by the extending sub-sections 266 and the bending sub-section 267 with different extending directions, resulting in a gap on the side of the bending sub-section 267 facing the insulating member 212. This increases the difficulty of transferring the high-temperature heat from laser welding to the insulating member 212, further increasing the difficulty of laser welding ablation of the insulating member 212 and further improving the reliability of the battery cell 20.

[0111] In some embodiments, the bent portion 267 bends from the extended portion 266 toward the interior of the battery cell 20.

[0112] The bending portion 267 can be bent along the thickness direction, width direction or other directions of the battery cell 20, but the bending direction is always pointing towards the inside of the battery cell 20.

[0113] In the above solution, by bending the bending portion 267 into the interior of the battery cell 20, the utilization rate of the internal space of the battery cell 20 can be increased, thereby increasing the energy density of the battery cell 20. Furthermore, since there is a gap between the bending portion 267 and the terminal body 262, when the bending portion 267 and the tab 232 are laser-welded, some of the heat generated by the laser will be lost in the air within the gap between the bending portion 267 and the terminal body 262, thus further reducing the risk of laser ablation of the insulating component 212.

[0114] Figure 12 This is a schematic diagram of the structure of the end cap assembly according to some embodiments of this application; Figure 13 This is a schematic diagram of the assembly of the end cap assembly and the electrode assembly according to some embodiments of this application; Figure 14 This is a schematic diagram of the assembly of the end cap assembly and the bent electrode tab according to some embodiments of this application.

[0115] Please refer to the following: Figures 12-14 In some embodiments, the bending sub-section 267 bends from the extension sub-section 266 toward the outside of the battery cell 20.

[0116] The bending portion 267 can be bent along the thickness direction, width direction or other directions of the battery cell 20, but the bending direction always points to the outside of the battery cell 20.

[0117] When two electrode assemblies 23 need to be welded to the same electrode terminal 26, the outwardly bent portion 267 forms an outwardly expanding spatial structure at the connection of the tabs 232. This structure forces the two tabs 232, which were originally parallel and close together, to be spaced apart when welded to the electrode terminal 26. For example, the distance between the tabs 232 can be increased from the conventional 3-5mm to 8-10mm, reducing the probability of short circuits caused by assembly errors or vibrations.

[0118] In the above solution, by bending the bending portion 267 outwards towards the battery cell 20, the distance between the tabs 232 of the two electrode assemblies 23 is increased when the two electrode assemblies 23 are welded to the same electrode terminal 26, which can reduce the short circuit risk of the two electrode assemblies 23.

[0119] In some embodiments, the bent portion 267 extends along a second direction Y, which is the thickness direction of the battery cell 20.

[0120] The tab 232 is typically bent along the thickness direction of the battery cell 20. Therefore, when the bent portion 267 extends along the thickness direction, its welding surface 263 naturally lies in the same plane or a near-plane as the tab 232. During assembly, the tab 232 can be directly attached to the welding surface 263, reducing the welding difficulty caused by spatial misalignment and making the welding operation more convenient.

[0121] In the above solution, by extending the bent portion 267 along the thickness direction of the battery cell 20, it is easier to weld it to the tab 232 of the electrode assembly 23, thereby increasing the welding area 263 between the electrode terminal 26 and the tab 232. The increased welding area 263 helps the current to be distributed more evenly between the tab 232 and the electrode terminal 26. During battery charging and discharging, the current can pass through the welding area more smoothly, which to some extent avoids local overheating caused by current concentration, reduces the risk of burning and breakage at the weld point, extends the service life of the battery cell 20, and also improves the stability and reliability of the battery cell 20 under high-rate charging and discharging conditions.

[0122] In some embodiments, the extension sub-part 266 extends along a first direction X.

[0123] In the above solution, by extending the extension sub-part 266 along the height direction of the battery cell 20, interference between the electrode terminal 26 and other structures inside the battery cell 20 can be prevented to a certain extent.

[0124] In some embodiments, there are two extension sub-parts 266 and two bending sub-parts 267. The two extension sub-parts 266 are respectively disposed on opposite sides of the terminal body 262, and the two bending sub-parts 267 are connected to the two extension sub-parts 266 in a one-to-one correspondence.

[0125] Two bent portions 267 are connected one-to-one with the extended portions 266, and the bending direction can be inward or outward. The bent portions 267 can extend along the thickness direction of the battery cell 20, and their welding surfaces 263 can be attached to the tabs 232 of the electrode assembly 23. This allows the two tabs 232 to be welded to their corresponding bent portions 267, enabling one electrode terminal 26 to connect to two electrode assemblies 23 simultaneously.

[0126] The two extension sub-sections 266 and the two bending sub-sections 267 can be symmetrically arranged. The symmetrical distribution of the extension sub-sections 266 and bending sub-sections 267 allows the stress on the electrode terminal 26 to be evenly distributed to both sides when subjected to external force, which to a certain extent avoids structural damage or solder joint cracking caused by excessive local stress. Under conditions such as battery vibration and compression, this structure can better maintain the connection stability between the electrode assembly 23 and the electrode terminal 26, and extend the battery life.

[0127] Connecting two electrode assemblies 23 via a single electrode terminal 26 reduces the number of terminals and space required, thereby increasing the battery's energy density. Welding two tabs 232 to the same electrode terminal 26 shortens the current transmission path, reduces internal resistance, and indirectly improves the battery's energy density and range.

[0128] In the above scheme, by connecting the two bent sub-parts 267 and the two extended sub-parts 266 in a one-to-one correspondence, one electrode terminal 26 can be simultaneously welded to the tabs 232 of two electrode assemblies 23, thereby improving the energy density of the battery cell 20.

[0129] In some embodiments, the welding surface 263 is a flat surface, which increases the contact area between the electrode terminal 26 and the tab 232 during welding and improves the welding effect.

[0130] The smooth welding surface 263, based on fundamental geometric principles, enables large-area surface-to-surface contact with the tab 232. Compared to uneven or textured surfaces, a smooth surface reduces local gaps and poor contact areas caused by surface irregularities. A smooth surface also reduces incomplete or false welds caused by poor contact. Incomplete welds can cause localized overheating of the battery cell 20 during charging and discharging, even posing safety hazards. The good contact of a smooth surface promotes full fusion of materials during welding, forming a strong connection, reducing such risks, and improving the safety and lifespan of the battery cell 20. The increased contact area directly reduces the contact resistance between the tab 232 and the electrode terminal 26. According to Ohm's law, the reduced contact resistance decreases the internal energy loss of the battery cell 20, improving the charging and discharging efficiency and energy utilization rate of the battery cell 20.

[0131] Secondly, embodiments of this application also provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0132] Thirdly, embodiments of this application also provide an electrical device, including the aforementioned battery device 100, which is used to provide electrical energy.

[0133] According to some embodiments of this application, this application provides a battery cell 20, which includes a housing 22, an electrode assembly 23, an end cap assembly 21, and an electrode terminal 26. The housing 22 has an opening. The electrode assembly 23 is disposed inside the housing 22 and includes a main body portion 231 and a tab 232 extending from the end of the main body portion 231. The end cap assembly 21 covers the opening of the housing 22 and includes an end cap 211 and an insulating member 212. The insulating member 212 is disposed on the side of the end cap 211 facing the electrode assembly 23, and the end cap 211 has an electrode lead-out hole 241. The electrode terminal 26 is at least partially accommodated in the electrode lead-out hole 241 and has a welding surface 263 for welding to the tab 232. Along a first direction X, the distance between the welding surface 263 and the insulating member 212 is H, where H ≥ 2.1 mm. The first direction X is the height direction of the battery cell 20. The welding surface 263 is located on the side of the electrode terminal 26 facing the electrode assembly 23.

[0134] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A battery cell, characterized by, include: The casing has an opening; An electrode assembly is disposed inside the housing, the electrode assembly including a main body and electrode tabs extending from an end of the main body; An end cap assembly is provided to cover the opening of the housing. The end cap assembly includes an end cap and an insulating member. The insulating member is disposed on the side of the end cap facing the electrode assembly. The end cap has an electrode lead-out hole. An electrode terminal is at least partially accommodated in the electrode lead-out hole. The electrode terminal has a welding surface for welding to the tab. The distance between the welding surface and the insulating member along a first direction is H, where H ≥ 2.1 mm. The first direction is the height direction of the battery cell.

2. The battery cell according to claim 1, characterized in that, The condition H satisfies: 5mm ≤ H ≤ 8mm.

3. The battery cell according to claim 1, characterized in that, The welding surface is located on the side of the electrode terminal facing the electrode assembly.

4. The battery cell according to any one of claims 1-3, characterized in that, The electrode terminal includes a connecting portion and a terminal body. The terminal body protrudes from the connecting portion and is at least partially accommodated in the electrode lead-out hole. The projection of the terminal body along the first direction is located within the projection of the connecting portion along the first direction, and the welding surface is located in the connecting portion.

5. The battery cell according to claim 4, characterized in that, The battery cell also includes a seal surrounding the terminal body, and at least a portion of the seal is clamped between the end cap and the connection portion.

6. The battery cell according to claim 5, characterized in that, Along the first direction, the distance between the welding surface and the seal is greater than the distance between the welding surface and the insulating element.

7. The battery cell according to claim 4, characterized in that, The connecting part includes a side wall and a bottom wall. The side wall is connected to the terminal body and is arranged around the bottom wall in a circumferential manner. The bottom wall is located on the side of the side wall away from the terminal body, and the welding surface is located on the bottom wall.

8. The battery cell according to claim 4, characterized in that, The connecting portion includes an extension portion and a bending portion. The extension portion is connected to the terminal body, and the bending portion is disposed on the side of the extension portion away from the terminal body. The welding surface is located on the bending portion. The extension directions of the extension portion and the bending portion are intersecting.

9. The battery cell according to claim 8, characterized in that, The bent portion bends from the extended portion toward the interior of the battery cell.

10. The battery cell according to claim 8, characterized in that, The bent portion bends outward from the extended portion toward the outside of the battery cell.

11. The battery cell according to claim 8, characterized in that, The bent portion extends along a second direction, which is the thickness direction of the battery cell.

12. The battery cell according to claim 8, characterized in that, The extended sub-part extends along the first direction.

13. The battery cell according to claim 8, characterized in that, The number of the extension sub-parts and the number of the bending sub-parts are both two. The two extension sub-parts are respectively disposed on opposite sides of the terminal body, and the two bending sub-parts are connected to the two extension sub-parts in a one-to-one correspondence.

14. The battery cell according to any one of claims 1-13, characterized in that, The welding surface is a flat surface.

15. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-14.

16. An electrical appliance, characterized in that, Includes the battery device according to claim 15, the battery device being used to provide electrical energy.

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