Battery cell, battery, electrical device, and energy storage device

Abstract

The present application pertains to the technical field of batteries, and provides a battery cell, a battery, an electrical device, and an energy storage device. The battery cell comprises an electrode assembly and a housing assembly, and the housing assembly comprises a first wall and an electrode terminal. The electrode terminal comprises a first conductive portion and a second conductive portion fixedly connected to each other. The second conductive portion is connected to a tab of the electrode assembly to form a connection portion. In a thickness direction of the first wall, an orthographic projection of the connection portion at least partially overlaps an orthographic projection of the first conductive portion.

Description

Battery cells, batteries, electrical devices and energy storage devices Technical Field

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

[0002] Energy conservation and emission reduction are key to the sustainable development of the automotive industry, and electric vehicles, due to their energy-saving and environmentally friendly advantages, have become an important component of this sustainable development. In the field of energy application, energy storage devices play a crucial role. They can be widely used in various power systems, renewable energy storage, and other scenarios to effectively store and release energy, improving energy utilization efficiency. For both electric vehicles and energy storage devices, battery technology is a critical factor in their development.

[0003] In a battery cell, the connection structure and quality between the tabs of the electrode assembly and the electrode terminals of the casing have a significant impact on the performance of the battery cell. If the connection between the tabs and the electrode terminals is not reasonable, it may lead to an increase in the connection resistance of the battery cell, which will generate a lot of heat when the current flows through, thereby affecting the performance of the battery. Summary of the Invention

[0004] This application aims to at least solve one of the technical problems existing in the prior art. To this end, one object of this application is to provide a battery cell, battery, power supply device, and energy storage device to reduce the heat generated when overcurrent occurs between the tab and the electrode terminals.

[0005] An embodiment of the first aspect of this application provides a battery cell including an electrode assembly and a housing assembly. The electrode assembly includes tabs, and the housing assembly includes a first wall and electrode terminals. The first wall includes a mounting hole, and the electrode terminals include a first conductive portion and a second conductive portion fixedly connected. The second conductive portion is at least partially located on the side of the first wall facing the electrode assembly, the first conductive portion at least partially passes through the mounting hole, and the second conductive portion is connected to the tabs to form a connection portion. Along the thickness direction of the first wall, the orthographic projection of the connection portion at least partially overlaps with the orthographic projection of the first conductive portion.

[0006] In the technical solution of this application embodiment, by making the electrode terminal include a first conductive part and a second conductive part, and connecting the second conductive part to the first conductive part and the tab of the electrode assembly, and by making the orthographic projection of the connection formed by the connection between the second conductive part and the tab at least partially overlap with the orthographic projection of the first conductive part along the thickness direction of the first wall, sufficient weld penetration is provided by the second conductive part and the first conductive part when welding the second conductive part and the tab. This is beneficial to improving the welding quality between the electrode terminal and the tab, increasing the current flow area between the electrode terminal and the tab, reducing the contact resistance, and thus reducing the heat generated when the current flows through the first conductive part. Furthermore, this embodiment can also reduce the thickness of the second conductive part, thereby saving the internal arrangement space of the battery cell, which is beneficial to improving the battery energy density.

[0007] In some embodiments, the side of the first conductive part facing the second conductive part has a plurality of spaced first protrusions. The first protrusions at least partially pass through the mounting hole and are fixedly connected to the second conductive part to increase the contact area between the first conductive part and the second conductive part. The multi-point connection method can also improve the connection reliability between the first conductive part and the second conductive part.

[0008] In some embodiments, the housing assembly further includes a sealing ring sandwiched between the first wall and the first conductive portion, the sealing ring at least partially sealing the gap between the first protrusion and the mounting hole. By providing a sealing ring between the mounting hole and the first protrusion, it is beneficial to maintain the relative position between the first wall and the first conductive portion, and to ensure good sealing performance of the battery cell.

[0009] In some embodiments, the housing assembly further includes a first insulating member disposed on the side of the first wall facing the electrode assembly. A second conductive portion abuts against the side of the first insulating member away from the first wall. The orthographic projection of the sealing ring onto the first wall at least partially overlaps with the orthographic projection of the second conductive portion onto the first wall. This allows the second conductive portion to provide support for both the first wall and the sealing ring, reducing the likelihood of seal failure and improving seal reliability.

[0010] In some embodiments, the side of the first protrusion facing the second conductive part has at least one second protrusion; the second conductive part has a through hole or blind hole corresponding to the second protrusion, and the second protrusion is at least partially disposed in the through hole or blind hole. By disposing at least part of the second protrusion in the through hole or blind hole on the second conductive part, it is beneficial to install and position the first conductive part and the second conductive part, and improve the accuracy of component assembly.

[0011] In some embodiments, the second protrusion and the second conductive portion are fixedly connected by riveting or welding. By using riveting or welding, the first conductive portion and the second conductive portion can be fixedly connected, improving the reliability of the connection.

[0012] In some embodiments, the second conductive portion includes a first surface and a second surface opposite to each other along the thickness direction. The first surface faces the first conductive portion, and the first surface has a third protrusion corresponding to at least one first protrusion. The third protrusion is used for fixed connection with the corresponding first protrusion. By having the first surface of the second conductive portion facing the first conductive portion have a third protrusion, and the third protrusion is fixedly connected with the corresponding first protrusion, a more compact and reliable connection between the second conductive portion and the first conductive portion is achieved, improving the space utilization rate inside the battery cell.

[0013] In some embodiments, the second surface has a groove located on the back side of the third protrusion. By providing a groove on the back side of the corresponding third protrusion, the molding difficulty of the third protrusion can be simplified. Furthermore, this embodiment is also more conducive to welding and fixing the third protrusion to the first conductive part, thereby achieving a reliable connection.

[0014] In some embodiments, the first wall includes a first portion, a second portion, and a transition portion connecting the first portion and the second portion; wherein the second portion is offset relative to the first portion in a direction away from the electrode assembly, and a mounting hole is formed in the second portion, and the outer contour of the orthographic projection of the second conductive portion on the first wall falls within the range of the outer contour of the second portion. By offsetting the second portion relative to the first portion in a direction away from the electrode assembly, the internal accommodating space of the battery cell can be increased, providing more arrangement space for the second conductive portion of the electrode terminal, which is beneficial to improving the energy density of the battery cell.

[0015] In some embodiments, the connection areas of the second conductive portion and the first protrusion are spaced apart from the connection portion. By spaced apart from the connection portion, welding is facilitated, and the problem of poor welding caused by the concentration of the connection areas of the tab, the first conductive portion, and the second conductive portion is also improved.

[0016] In some embodiments, the first conductive portion includes a plurality of sub-conductive portions, with an insulating portion sandwiched between two adjacent sub-conductive portions, and a first protrusion on the side of the sub-conductive portion facing the second conductive portion. By including a plurality of mutually insulated sub-conductive portions in the first conductive portion, multiple independent electrical connection terminals can be formed on the outside of a single electrode terminal, which is beneficial for connecting the electrode terminal to different components or connection objects respectively, thereby improving the flexibility of connection.

[0017] In some embodiments, the battery cell further includes a retainer disposed on the surface of the first wall away from the electrode assembly and used to secure the first conductive portion. The retainer improves the stability and reliability of the electrode terminal mounting.

[0018] In some embodiments, the second conductive portion includes a metal layer and a flux layer, the flux layer being located on the side surface of the metal layer facing the electrode assembly and / or the side surface of the metal layer facing the first conductive portion. By including a metal layer and a flux layer in the second conductive portion, the welding quality of the second conductive portion can be improved, the reliability of the connection can be increased, and the contact resistance can be reduced.

[0019] In some embodiments, the electrode assembly includes a first electrode assembly and a second electrode assembly. Both the first and second electrode assemblies include a positive electrode tab and a negative electrode tab, and the electrode terminals include a first electrode terminal and a second electrode terminal. The positive electrode tabs of the first and second electrode assemblies are fixedly connected to the second conductive portion of the first electrode terminal, and the negative electrode tabs of the first and second electrode assemblies are fixedly connected to the second conductive portion of the second electrode terminal. By providing two electrode assemblies connected to the electrode terminals within the housing, the capacity and energy density of a single battery cell, as well as the overall charge-discharge performance of the battery cell, can be improved.

[0020] In some embodiments, the first conductive portion of the second electrode terminal is different from the base metal of the second conductive portion of the second electrode terminal. This better meets the welding requirements caused by different welding objects and improves the quality of the connection.

[0021] In some embodiments, the base metal of the first conductive portion of the second electrode terminal is aluminum or steel, and the base metal of the second conductive portion of the second electrode terminal is copper. This allows for better adaptation to subsequent welding processes and improves the overall quality of the battery.

[0022] In some embodiments, the base metal of the first conductive portion of the first electrode terminal and the base metal of the second conductive portion of the first electrode terminal are the same. This allows for good welding performance between the first conductive portion and the second conductive portion of the first electrode terminal.

[0023] In some embodiments, the base metal of the first conductive portion and the second conductive portion of the first electrode terminal is aluminum. This allows for good welding performance between the first electrode terminal and the positive electrode tab, improving the welding quality between the first electrode terminal and the positive electrode tab.

[0024] An embodiment of the second aspect of this application provides a battery comprising the battery cell described in the above embodiments.

[0025] An embodiment of the third aspect of this application provides an electrical device that includes the battery described in the above embodiments, the battery being used to provide electrical energy.

[0026] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery described in the above embodiments, the battery being used for energy storage.

[0027] 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

[0028] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application. Figure 1 is a structural schematic diagram of a vehicle according to some embodiments of this application; Figure 2 is an exploded structural schematic diagram of a battery according to some embodiments of this application; Figure 3 is an exploded structural schematic diagram of a battery cell according to some embodiments of this application; Figure 4 is a connection structural schematic diagram of an electrode assembly and a housing assembly according to some embodiments of this application; Figure 5 is a top view of the connection between an electrode assembly and a housing assembly according to some embodiments of this application; Figure 6 is a top view of a housing assembly according to some embodiments of this application; Figure 7 is a cross-sectional schematic diagram obtained by cutting along the PP cutting line in Figure 6; Figure 8 is a cross-sectional schematic diagram of the exploded structure of a housing assembly according to some embodiments of this application; Figure 9 is a structural schematic diagram of a first wall and a second conductive part according to some embodiments of this application; Figure 10 is a structural schematic diagram of a first wall, a first conductive part, and a second conductive part according to some embodiments of this application; Figure 11 is a schematic diagram of the positional relationship between a first wall, a first conductive part, and a second conductive part according to some embodiments of this application; Figure 12 is a schematic diagram of the positional relationship between a first conductive part and an insulating member according to some embodiments of this application; Figure 13 is a cross-sectional schematic diagram obtained by cutting along the QQ cutting line in Figure 12; Figure 14 is a structural schematic diagram of a metal layer and a flux layer according to some embodiments of this application.

[0029] Explanation of reference numerals in the attached drawings: Vehicle 1000; Battery 100, Controller 200, Motor 300; Housing 10, First Component 11, Second Component 12; Battery Cell 20, Housing Assembly 21, First Wall 211, First Part 211A, Transition Part 211B, Second Part 211C, Mounting Hole 2111, Cantilever Area 2112, Electrode Terminal 212, First Electrode Terminal 212A, Second Electrode Terminal 212B, First Conductive Part 2121, First Protrusion 2121A, Second Protrusion 2121B, Top 2121C, Sub-Conductive Part 2121D, Insulator 2121E, Second Conductive Part 2122, First Surface 2122A, Second Surface 2122B, Through Hole 2122C, Third Protrusion 2122D, Groove 2122E, Metal Layer 2122F, Solder Flux Layer 2122G First insulating member 2131, second insulating member 2132, sealing ring 2133, housing 22, electrode assembly 23, first electrode assembly 231, second electrode assembly 232, tab 23a, positive tab 2311 of the first electrode assembly, negative tab 2312 of the first electrode assembly, positive tab 2321 of the second electrode assembly, negative tab 2322 of the second electrode assembly; connecting part 24a; fixing member 25. Detailed Implementation

[0030] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0032] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0033] In this document, the term "embodiment" means that a particular 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 separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0034] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0035] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0036] In the description of the embodiments of this application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of 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. Therefore, they should not be construed as limitations on the embodiments of this application.

[0037] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0038] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0039] Within the internal structure of a battery cell, the tabs of the electrode assembly are electrically connected to the electrode terminals, allowing current to flow smoothly into and out of the battery, thus enabling external discharge or charging of the battery cell. When the connection between the tabs and electrode terminals is improper—for example, due to insufficient welding quality resulting in incomplete soldering or false soldering, or because the contact area between the tabs and electrode terminals is too small—the effective conductive path between them is reduced, contact resistance increases, and consequently, a large amount of heat is generated during overcurrent, adversely affecting battery performance and cycle life.

[0040] Based on the above considerations, in order to control overcurrent heat generation, this application provides a battery cell including an electrode assembly and a housing assembly. The electrode assembly includes tabs; the housing assembly includes a first wall and electrode terminals. The first wall includes mounting holes; the electrode terminals include a first conductive portion and a second conductive portion fixedly connected, the second conductive portion being at least partially located on the side of the first wall facing the electrode assembly, the first conductive portion at least partially passing through the mounting holes, and the second conductive portion connecting to the tabs to form a connection portion. Along the thickness direction of the first wall, the orthographic projection of the connection portion at least partially overlaps with the orthographic projection of the first conductive portion. By constructing the electrode terminals to include connected first and second conductive portions, and ensuring that the orthographic projection of the connection portion formed by the connection of the second conductive portion and the tabs at least partially overlaps with the orthographic projection of the first conductive portion along the thickness direction of the first wall, the weld penetration depth is improved, which is beneficial for improving the connection quality and overcurrent area between the tabs and the electrode terminals, thereby reducing the heat generated when current flows through the first conductive portion. Furthermore, the thickness of the second conductive portion can be reduced, which is beneficial for improving the battery energy density.

[0041] The battery cells disclosed in this application can be used, but are not limited to, in electrical devices or energy storage devices such as vehicles, ships, or aircraft. A power system comprising the battery cells and batteries disclosed in this application can be used to construct such an electrical device, which helps to reduce the heat generated when excessive current flows through the terminals during overcurrent.

[0042] 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.

[0043] 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.

[0044] Please refer to Figure 1, which is a schematic diagram of the vehicle structure 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. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is installed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 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 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0045] In some embodiments of this application, the battery 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.

[0046] Please refer to Figure 2, which is an exploded structural diagram of a battery provided in some embodiments of this application. The battery 100 includes a housing 10 and a battery cell 20, with the battery cell 20 housed within the housing 10. The housing 10 provides a space for the battery cell 20 and can have various structures. In some embodiments, the housing 10 may include a first component 11 and a second component 12, which overlap each other, jointly defining a space for accommodating the battery cell 20. The second component 12 may be a hollow structure with one open end, and the first component 11 may be a plate-like structure, covering the open side of the second component 12 so that the first component 11 and the second component 12 jointly define the space. Alternatively, the first component 11 and the second component 12 may both be hollow structures with one open side, with the open side of the first component 11 covering the open side of the second component 12. Of course, the housing 10 formed by the first component 11 and the second component 12 can have various shapes, such as a cylinder, a cuboid, etc.

[0047] In battery 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 configurations. Multiple battery cells 20 can be directly connected in series, parallel, or in a mixed manner, and then the entire assembly of the multiple battery cells 20 is housed within the housing 10. Alternatively, battery 100 can also be composed of multiple battery cells 20 first connected in series, parallel, or in a mixed manner to form a battery module, and then multiple battery modules are connected in series, parallel, or in a mixed manner to form a whole, which is also housed within the housing 10. Battery 100 may also include other structures; for example, it may include a busbar component for electrical connection between the multiple battery cells 20.

[0048] 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 to these. The battery cell 20 can be cylindrical, flat, cuboid, or other shapes.

[0049] Please refer to Figure 3, which 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 assembly 21, a housing 22, and an electrode assembly 23.

[0050] The outer casing assembly 21 refers to the 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 outer casing assembly 21 can be adapted to the shape of the housing 22 to fit it. Optionally, the outer casing assembly 21 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that the outer casing assembly 21 is not easily deformed under pressure or impact, giving the battery cell 20 higher structural strength and improving safety performance. Functional components such as electrode terminals 212 can be provided on the outer casing assembly 21. The electrode terminals 212 can be used to electrically connect with the electrode assembly 23 for outputting or inputting electrical energy into the battery cell 20. In some embodiments, the outer casing assembly 21 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 material of the outer casing assembly 21 can also be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc. In some embodiments, an insulating element may also be provided inside the housing assembly 21. The insulating element can be used to isolate the electrical connection components within the housing 22 from the housing assembly 21 to reduce the risk of short circuits. Exemplarily, the insulating element may be made of plastic, rubber, etc.

[0051] The housing 22 is a component used to cooperate with the outer casing assembly 21 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 23, electrolyte, and other components. The housing 22 and the outer casing assembly 21 can be independent components. An opening can be provided on the housing 22, and the outer casing assembly 21 can close the opening to form the internal environment of the battery cell 20. Alternatively, the outer casing assembly 21 and the housing 22 can be integrated. Specifically, the outer casing assembly 21 and the housing 22 can form a common connecting surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 22, the outer casing assembly 21 closes the housing 22. The housing 22 can be of various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 22 can be determined according to the specific shape and size of the electrode assembly 23. The housing 22 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0052] Electrode assembly 23 is the component in the battery cell 20 where electrochemical reactions occur. The casing 22 may contain one or more electrode assemblies 23. The electrode assembly 23 is mainly formed by winding or stacking positive and negative electrode plates, and typically a separator is provided between the positive and negative electrode plates. The portions of the positive and negative electrode plates containing active material constitute the main body of the electrode assembly, while the portions of the positive and negative electrode plates without active material each constitute a tab 23a. The positive and negative tabs may be located together at one end of the main body or separately at both ends of the main body. During the charging and discharging process of the battery, the positive and negative active materials react with the electrolyte, and the tabs 23a connect to the electrode terminals to form a current loop.

[0053] Please refer to Figures 3 and 4 to 8. Figure 4 is a schematic diagram of the connection structure of the electrode assembly and the housing assembly in some embodiments of this application. Figure 5 is a top view of the connection between the electrode assembly and the housing assembly in some embodiments of this application. Figure 6 is a top view of the housing assembly in some embodiments of this application. Figure 7 is a schematic diagram of the cross section obtained by cutting along the PP cutting line in Figure 6. Figure 8 is a schematic diagram of the exploded structure of the housing assembly in some embodiments of this application.

[0054] This application provides a battery cell 20, including an electrode assembly 23 and a housing assembly 21. The electrode assembly 23 includes a tab 23a. The housing assembly 21 includes a first wall 211 and electrode terminals 212. The first wall 211 includes a mounting hole 2111. The electrode terminal 212 includes a first conductive portion 2121 and a second conductive portion 2122 fixedly connected. The second conductive portion 2122 is at least partially located on the side of the first wall 211 facing the electrode assembly 23. The first conductive portion 2121 is at least partially inserted through the mounting hole 2111. The second conductive portion 2122 is connected to the tab 23a to form a connection portion 24a. Along the thickness direction of the first wall 211, the orthographic projection of the connection portion 24a at least partially overlaps with the orthographic projection of the first conductive portion 2121.

[0055] It should be noted that the battery cell 20 may also include a housing 22 with an opening for accommodating the electrode assembly 23, and the housing assembly 21 is connected to the housing 22 to close its opening.

[0056] Electrode terminals 212 are disposed on the housing assembly 21 for conducting electrical connections between the electrode assembly 23 inside the housing and external electrical devices outside the housing. A first wall 211 serves as a carrier for mounting the electrode terminals 212. The first wall 211 may be a plate-like structural member. The housing assembly 21 may also include a second wall connected to the first wall 211 and a third wall disposed opposite to the first wall 211. In some embodiments, the first wall 211 may be a top cover of the housing assembly 21, and the second and third walls together constitute the housing 22. In other embodiments, the first wall 211 may be any wall surface of the housing 22, such as a side wall or a bottom wall.

[0057] The mounting hole 2111 is a through hole extending through the first wall 211 along its thickness direction. The shape of the mounting hole 2111 can be any closed shape formed by at least one of straight lines and curves, including but not limited to oval holes, square holes, and circular holes. In some embodiments, the shape of the mounting hole 2111 can be a racetrack-shaped closed shape formed by connecting straight lines and arcs. The electrode terminal 212 can be adapted to the shape of the mounting hole 2111 for easy installation. The number of mounting holes 2111 can be determined according to the number of electrode terminals 212. In some embodiments, the first wall 211 is provided with two spaced mounting holes 2111 for mounting the corresponding electrode terminals for the positive and negative leads, respectively.

[0058] The electrode terminal 212 may include two parts: a first conductive part 2121 and a second conductive part 2122. The second conductive part 2122 is located on the side of the first wall 211 facing the electrode assembly 23, while the first conductive part 2121 passes through the mounting hole 2111. Here, "passing through" means that at least a portion of the first conductive part 2121 is located inside the mounting hole 2111. It can be understood that the first conductive part 2121 also includes a portion located on the side of the first wall 211 facing away from the electrode assembly 23 for electrical connection with the outside.

[0059] The first conductive part 2121 and the second conductive part 2122 can be two parts of an integrally formed component, or they can be two independent components connected to each other to form the electrode terminal 212. The first conductive part 2121 and the second conductive part 2122 can be made of the same material or different materials, and this application embodiment does not limit this.

[0060] In some embodiments, the outer contour area of ​​the orthographic projection of the first conductive portion 2121 onto the first wall 211 is smaller than the outer contour area of ​​the orthographic projection of the second conductive portion 2122 onto the first wall 211. The outer contour area Sa of the orthographic projection of the first conductive portion 2121 onto the first wall 211 refers to the area defined by the outer contour of a projection pattern perpendicular to the surface of the first wall 211 (e.g., the lower surface facing the electrode assembly) or along the thickness direction of the first wall 211 projected onto the surface of the first wall 211 (e.g., the lower surface). Correspondingly, the outer contour area Sb of the orthographic projection of the first conductive portion 2121 onto the first wall 211 is also the area defined by the outer contour of a projection pattern perpendicular to the surface of the first wall 211 (e.g., the lower surface facing the electrode assembly) or along the thickness direction of the first wall 211 projected onto the surface of the first wall 211. Sa being less than Sb means that the dimension of the second conductive portion in the direction parallel to the lower surface of the first wall 211 is greater than the dimension of the first conductive portion in the same direction. This allows the second conductive portion 2122 to form a limiting structure with the first wall 211, and also provides a larger welding area for welding to the tab 23a. In some embodiments, the lower surface of the second conductive portion 2122 away from the first wall 211 is used for welding to the tab 23a.

[0061] In some embodiments, the orthographic projection of the connection portion 24a falls entirely within the range of the first conductive portion along the thickness direction of the first wall 211, which can reduce the probability of the electrode terminal 212 being soldered through.

[0062] By including a first conductive portion 2121 and a second conductive portion 2122 in the electrode terminal 2122, and connecting the first conductive portion 2121 and the tab 23a of the electrode assembly 23 with the second conductive portion 2122 connected to the first conductive portion 2121, and ensuring that the orthographic projection of the connection portion 24a formed by the connection of the second conductive portion 2122 and the tab 23a overlaps at least partially with the orthographic projection of the first conductive portion 2121 in the thickness direction of the first wall 211, sufficient weld penetration is provided by the second conductive portion 2122 and the first conductive portion 2121 during welding. This improves the welding quality between the electrode terminal 212 and the tab 23a, increases the current-carrying area and current-carrying capacity between the electrode terminal 212 and the tab 23a, reduces contact resistance, and consequently reduces the heat generated when current flows through the first conductive portion 2121. Furthermore, the thickness of the second conductive portion 2122 can be reduced, thereby saving internal arrangement space in the battery cell 20 and thus improving the battery energy density.

[0063] According to some embodiments of this application, please continue to refer to Figures 7 and 8. The first conductive part 2121 has a plurality of first protrusions 2121A spaced apart on the side facing the second conductive part 2122. The first protrusions 2121A at least partially pass through the mounting hole 2111 and are fixedly connected to the second conductive part 2122.

[0064] The first protrusion 2121A is a structure or component that protrudes from the side surface of the first conductive part 2121 facing the second conductive part 2122. The number of first protrusions 2121A can be two or more, such as three, four or five, etc.

[0065] The number of mounting holes 2111 corresponding to a single electrode assembly 23a can be multiple, and can be determined based on the number of first protrusions 2121A.

[0066] The outer contour of the first protrusion 2121A can be circular, square, or other shapes. The second conductive part 2122 can be electrically and fixedly connected to the first protrusion 2121A by welding or riveting.

[0067] In some embodiments, the first protrusion 2121A may be a protruding cylindrical structure that is inserted into the mounting hole 2111, and the second conductive part 2122 is a flat plate structure that is welded and fixed to the first protrusion 2121A.

[0068] In some embodiments, the number of mounting holes 2111 is the same as the number of first protrusions 2121A and they are provided in a one-to-one correspondence; each first protrusion 2121A passes through the corresponding mounting hole 2111 and is fixedly connected to the second conductive part 2122.

[0069] By having a plurality of first protrusions 2121A on the side of the first conductive part 2121 facing the second conductive part 2122, and the first protrusions 2121A at least partially passing through the mounting hole 2111 and fixedly connected to the second conductive part 2122, the contact area between the first conductive part 2121 and the second conductive part 2122 is increased. The multi-point connection method can also improve the connection reliability of the first conductive part 2121 and the second conductive part 2122.

[0070] According to some embodiments of this application, please continue to refer to Figures 7 and 8. The housing assembly 21 may also include a sealing ring 2133. The sealing ring 2133 is sandwiched between the first wall 211 and the first conductive portion 2121, and the sealing ring 2133 is at least partially used to seal the gap between the first protrusion 2121A and the mounting hole 2111.

[0071] The sealing ring 2133 can be any feasible sealing member that is sleeved on the outer periphery of the first protrusion 2121A to seal the gap between the first protrusion 2121A and the mounting hole 2111. Specifically, the sealing ring 2133 can achieve gap sealing through elastic deformation. For example, the sealing ring 2133 can seal the gap between the first protrusion 2121A and the mounting hole 2111 by contacting the edges of the first protrusion 2121A and the mounting hole 2111 respectively and deforming under external pressure.

[0072] In some embodiments, the housing assembly 21 includes a plurality of sealing rings 2133, and the plurality of sealing rings 2133 are disposed in a one-to-one correspondence with the first protrusion 2121A.

[0073] In some embodiments, the two first protrusions 2121A are spaced apart, and the sealing rings 2133 corresponding to the two first protrusions 2121A can also be sleeved on the outer peripheral surface of the first protrusions 2121A. The cantilever area 2112 between the two mounting holes 2111 of the first wall 211 can provide support for the sealing rings 2133.

[0074] By providing a sealing ring 2133 between the mounting hole 2111 and the first protrusion 2121A, it is beneficial to maintain the relative position between the first wall 211 and the first conductive part 2121, and the battery cell 20 can have good sealing performance.

[0075] According to some embodiments of this application, as shown in Figures 7 and 8, the housing assembly 21 further includes a first insulating member 2131, which is disposed on the side of the first wall 211 facing the electrode assembly 23. The second conductive portion 2122 abuts against the side of the first insulating member 2131 away from the first wall 211, and the orthographic projection of the sealing ring 2133 on the first wall 211 at least partially overlaps with the orthographic projection of the second conductive portion 2122 on the first wall 211.

[0076] The first insulating member 2131 is an insulating member located on the side of the first wall 211 facing the electrode assembly 23, used to provide an insulating gap between the first wall 211 and the electrode assembly 23, and between the first wall 211 and the second conductive part 2122, to prevent short circuits. The first insulating member 2131 can be made of any insulating material, such as plastic, rubber, etc.

[0077] In some embodiments, the first insulating member 2131 may be a lower plastic, which is attached to the lower surface of the first wall 211 facing the electrode assembly 23. The second conductive part 2122 is flat, and the side surface (upper surface) of the second conductive part 2122 away from the electrode assembly 23 abuts against the side surface (lower surface) of the first insulating member 2131 away from the first wall 211.

[0078] In some embodiments, a relatively narrow cantilever region 2112 is formed between two adjacent mounting holes 2111 of the first wall 211. The sealing ring 2133 is positioned and installed by defining the area of ​​the mounting holes 2111 by the outer peripheral surface of the first conductive part 2121 and the first wall 211. Since the mounting holes 2111 weaken the structural strength of the first wall 211, especially the cantilever region 2112 located between adjacent mounting holes 2111, the structural strength is weakened more significantly. When the battery cell is subjected to external impact or internal expansion, the first wall 211 is prone to deformation, which in turn affects the sealing effect of the sealing ring 2133.

[0079] The orthographic projection of the sealing ring 2133 onto the first wall 211 and the orthographic projection of the second conductive part 2122 onto the first wall 211 at least partially overlap. That is, the second conductive part 2122 abuts against the back side of the first wall 211 that contacts the sealing ring 2133. This allows for the positioning of the electrode terminal 21, reducing the arrangement space occupied by the electrode terminal within the battery cell 20. On the other hand, the second conductive part 2122 can provide strength support for the first wall 211 in the area where the sealing ring 2133 is located. In particular, the second conductive part 212 abuts against at least a portion of the cantilever region 2112, which can significantly enhance the deformation resistance of the cantilever region 2112, thus improving the reliability of the seal.

[0080] A support member may also be provided between the sealing rings 2133 corresponding to the two adjacent first protrusions 2121A. The two side surfaces of the support member abut against the two sealing rings 2133 respectively to limit the sealing rings 2133. The support member may be made of the same or different material as the sealing rings 2133.

[0081] By placing the second conductive part 2122 against the side of the first insulating member 2131 away from the first wall 211, and ensuring that the orthographic projection of the sealing ring 2133 on the first wall 211 at least partially overlaps with the orthographic projection of the second conductive part 2122 on the first wall 211, the second conductive part 2122 can provide support for the first wall 211 while also providing support for the sealing ring 2133, thereby reducing the possibility of seal failure and improving the reliability of the seal.

[0082] According to some embodiments of this application, as shown in Figures 8 and 9, Figure 9 is a schematic diagram of the structure of the first wall and the second conductive part in some embodiments of this application. The first protrusion 2121A has at least one second protrusion 2121B on the side facing the second conductive part 2122. The second conductive part 2122 has a through hole 2122C or a blind hole corresponding to the second protrusion 2121B. The second protrusion 2121B is at least partially disposed in the through hole 2122C or the blind hole.

[0083] The second protrusion 2121B refers to the portion protruding from the surface of the first conductive portion 2121 facing the second conductive portion 2122. The second protrusion 2121B can be one or multiple protrusions spaced apart. This application embodiment does not limit this.

[0084] A through hole 2122C refers to a hole that penetrates the second conductive portion 2122 along the thickness direction, while a blind hole is a hole that does not penetrate the second conductive portion 2122 along the thickness direction. In some examples, a blind hole can be a groove.

[0085] The shape and size of the second protrusion 2121B can be adapted to the through hole 2122C or the blind hole, so that the two can be inserted. This application embodiment does not impose specific limitations on this.

[0086] By placing at least a portion of the second protrusion 2121B within the through hole 2122C or blind hole on the second conductive part 2122, it is beneficial to the installation and positioning of the first conductive part 2121 and the second conductive part 2122, thereby improving the accuracy of component assembly.

[0087] According to some embodiments of this application, the second protrusion 2121B and the second conductive part 2122 are fixedly connected by riveting or welding.

[0088] Riveting is a mechanical connection method that involves inserting a rivet into a pre-drilled hole in the parts to be connected, and then applying external force to plastically deform the tail of the rivet to form a new head, thereby tightly connecting the parts together. In this embodiment, the second protrusion 2121B can be constructed as a rivet, inserted into the hole in the second conductive part 2122, and deformed under the action of external force, thereby achieving a fixed connection between the first conductive part 2121 and the second conductive part 2122.

[0089] The second protrusion 2121B and the second conductive part 2122 can also be fixed by welding. For example, laser welding can be used to fuse and fix the second protrusion 2121B and the second conductive part 2122. Specifically, butt welding or through welding can be used. This application embodiment does not limit this.

[0090] By using riveting or welding, the first conductive part 2121 and the second conductive part 2122 can be fixedly connected, thereby improving the reliability of the connection.

[0091] Please refer to Figure 10, which is a schematic diagram of the structure of the first wall, the first conductive part, and the second conductive part in some embodiments of this application.

[0092] According to some embodiments of this application, the second conductive portion 2122 includes a first surface 2122A and a second surface 2122B that are opposite each other in the thickness direction. The first surface 2122A faces the first conductive portion 2121, and the first surface 2122A has a third protrusion 2122D that is disposed corresponding to at least one first protrusion 2121A. The third protrusion 2122D is used to be fixedly connected to the corresponding first protrusion 2121A.

[0093] The third protrusion 2122D refers to the portion of the second conductive portion 2122 that protrudes from the first surface 2122A. The number of third protrusions 2122D can be one or more. In some embodiments, each first protrusion 2121A can be simultaneously mated and fixed with multiple spaced third protrusions 2122D.

[0094] The third protrusion 2122D and the first protrusion 2121A can be fixed by welding or by other conductive fixing methods.

[0095] In some embodiments, the third protrusion 2122D protrudes away from the electrode assembly 23 and is used to abut against the first conductive portion 2121 and connect with each other, while the first surface 2122A without the third protrusion 2122D abuts against the first insulating member 2131, which can reduce the arrangement space inside the housing occupied by the electrode terminal 21.

[0096] By providing a third protrusion 2122D on the first surface 2122A of the second conductive part 2122, and fixing the third protrusion 2122D to the corresponding first protrusion 2121A, a more compact and reliable connection between the second conductive part 2122 and the first conductive part 2121 is achieved, thereby improving the space utilization rate inside the battery cell.

[0097] According to some embodiments of this application, the second surface 2122B has a groove 2122E, which is located on the back side of the third protrusion 2122D.

[0098] The groove 2122E refers to a structure formed by recessing relative to the second surface 2122B, and the groove 2122E and the third protrusion 2122D are arranged back to back. In some embodiments, the groove 2122E and the third protrusion 2122D can be formed by stamping the second conductive portion 2122.

[0099] The groove 2122E can reduce the thickness at the location of the third protrusion 2122D. During connection, the third protrusion 2122D can be fixedly connected to the first conductive part 2121 by laser penetration welding. Specifically, the laser can be shot from the side where the groove 2122E is located to the back of the third protrusion 2122D, penetrate the third protrusion 2122D to melt it, and then fix it to the first conductive part 2121.

[0100] By providing a groove 2122E on the back side of the corresponding third protrusion 2122D, the molding difficulty of the third protrusion 2122D can be simplified. In addition, it is also more convenient to weld and fix the third protrusion 2122D to the first conductive part 2121, so as to achieve a reliable connection.

[0101] Please refer to Figure 11, which is a schematic diagram showing the positional relationship between the first wall, the first conductive part, and the second conductive part in some embodiments of this application.

[0102] According to some embodiments of this application, the first wall 211 includes a first portion 211A, a second portion 211C, and a transition portion 212B connecting the first portion 211A and the second portion 211C. The second portion 211C is offset relative to the first portion 211A in a direction away from the electrode assembly 23, and a mounting hole 2111 is formed in the second portion. The outer contour of the orthographic projection of the second conductive portion 2122 onto the first wall 211 falls within the range of the outer contour of the second portion 211C.

[0103] The second part 211C is offset away from the first part 211A in a direction away from the electrode assembly 23. That is, in the same direction as the thickness direction of the first wall 211, the distance between the first part 211A and the electrode assembly 23 is less than the distance between the second part 211C and the electrode assembly 23, so that more space can be provided inside the battery casing.

[0104] Mounting hole 2111 is formed in the second part 211C and extends through the second part 211C in the thickness direction. The outer contour area of ​​the second part 211C is larger than the outer contour area of ​​the second conductive part 2122, so that at least a portion of the second conductive part 2122 can be accommodated in the space defined by the second part 211C and the transition part 211B.

[0105] Understandably, in order to achieve insulation, the structure of the first insulating member 2131 is the same as that of the first wall 211, so that the first insulating member 2131 can fit well with the first part 211A, the transition part 212B and the second part 211C of the first wall 211.

[0106] In some embodiments, the second surface of the second conductive portion 2122 facing the electrode assembly is flush with the lower surface of the first insulating member 2131 below the first portion 211A facing the electrode assembly 23.

[0107] By offsetting the second part 211C relative to the first part 211A to the side away from the electrode assembly 23, and by opening the mounting hole 2111 in the second part, the outer contour of the second conductive part 2122 projected onto the first wall 211 falls within the range of the outer contour of the second part 211C, the internal accommodating space of the battery cell can be increased. This provides more space for the arrangement of the second conductive part 2122 of the electrode terminal 212, which is beneficial to improving the energy density of the battery cell 20.

[0108] According to some embodiments of this application, as shown in Figures 4 to 5, the connection area between the second conductive part 2122 and the first protrusion 2121A is spaced apart from the connection part 24a.

[0109] In some embodiments, the second conductive portion 2122 and the first protrusion 2121A can be welded to form a first welded portion, and the second conductive portion 2122 and the tab 23a can also be welded to form a second welded portion. The specific welding method can be selected according to the material; for example, laser welding can be used between the second conductive portion 2122 and the first protrusion 2121A, and ultrasonic welding can be used between the second conductive portion 2122 and the tab 23a. The interval between the connection area of ​​the second conductive portion 2122 and the first protrusion 2121A and the connection portion 24a means that the first welded portion and the second welded portion are staggered.

[0110] In some embodiments, along the thickness direction of the first wall 211, the orthographic projection of the connecting portion 24a falls completely within the range of the first conductive portion 2121, the orthographic projection of the connecting portion 24a does not overlap with the orthographic projection of the first insulating member 2131, and the orthographic projection of the connecting portion 24a does not overlap with the orthographic projection of the sealing ring 2133, so as to prevent the electrode terminal 212 from being soldered through, damaging the first insulating member 2131 and the sealing ring 2133, and improving safety.

[0111] By spacing the connection area of ​​the second conductive part 2122 and the first protrusion 2121A from the connection part 24a, welding is facilitated, and the problem of poor welding caused by the overlap of the connection areas of the tab 23a, the first conductive part 2121, and the second conductive part 2122 is also improved.

[0112] Please refer to Figures 12 and 13. Figure 12 is a schematic diagram of the positional relationship between the first conductive part and the insulating part in some embodiments of this application, and Figure 13 is a schematic diagram of the cross section obtained by cutting along the QQ cutting line in Figure 12.

[0113] According to some embodiments of this application, the first conductive part 2121 includes a plurality of sub-conductive parts 2121D, an insulating part 2121E is sandwiched between two adjacent sub-conductive parts 2121D, and a first protrusion 2121A is provided on the side of the sub-conductive part 2121D facing the second conductive part 2122.

[0114] The first conductive portion 2121 can be configured as multiple independent sub-conductive portions 2121D. Two adjacent sub-conductive portions 2121D are insulated from each other by an insulating portion 2121E. Each sub-conductive portion 2121D has at least one of the aforementioned first protrusions 2121A, thus enabling conductive connection between the sub-conductive portion 2121D and the second conductive portion 2122. The multiple sub-conductive portions 2121D can have different shapes and sizes to facilitate connection with different objects.

[0115] In the technical solution of this application embodiment, the first conductive part 2121 includes a plurality of mutually insulated sub-conductive parts 2121D, which can enable a single electrode terminal 21 to form multiple independent electrical connection terminals outside the battery cell, which is beneficial for the electrode terminal 21 to be connected to different components or connection objects respectively, thereby improving the flexibility of connection.

[0116] According to some embodiments of this application, as shown in Figures 7-8, 10 and 13, the battery cell further includes a fixing member 25, which is disposed on the side surface of the first wall 211 away from the electrode assembly 23 and is used to fix the first conductive part 2121.

[0117] The fastener 25 is a component used to fix the first conductive part 2121, and the fastener 25 may include a metal component. The fastener 25 may be correspondingly disposed at the junction of the first conductive part 2121 and the first wall 211. The fastener 25 is welded to the first wall 211 and abuts against the first conductive part 2121 to achieve a fixed connection between the fastener 25 and the first wall 211 and to fix the first conductive part 2121.

[0118] A second insulating layer 2132 may be provided on the surface of the fastener 25 to achieve insulation between the fastener 25 and the first conductive part 2121, thereby insulating the first wall 211 from the first conductive part 2121. The second insulating layer 2132 is made of insulating material.

[0119] By placing the fastener 25 on the side of the first wall 211 away from the electrode assembly 23 and using it to fix the first conductive part 2121, the stability and reliability of the electrode terminal 212 installation are improved.

[0120] Please refer to Figure 14, which is a schematic diagram of the structure of the metal layer and flux layer in some embodiments of this application.

[0121] According to some embodiments of this application, the second conductive portion 2122 may include a metal layer 2122F and a flux layer 2122G, wherein the flux layer 2122G is located on at least a portion of the surface of the metal layer 2122F. In some embodiments, the flux layer 2122G is located on the surface of the metal layer 2122F facing the electrode assembly 23. In other embodiments, the flux layer 2122G is located on the surface of the metal layer 2122F facing the first conductive portion 2121. In still other embodiments, the flux layer 2122G is located on both the surface of the metal layer 2122F facing the electrode assembly 23 and the surface of the metal layer 2122F facing the first conductive portion 2121.

[0122] The metal layer 2122F may be a portion of the base metal of the second conductive part 2122, and the specific material may be selected according to the object being connected or the needs of the connection. For example, the metal layer 2122F may include one or more combinations of metal materials such as aluminum and copper.

[0123] The flux layer 2122G is a material layer disposed on the surface of the metal layer 2122F, which can be used to improve the welding quality of dissimilar metals. The flux layer 2122G can be located on the surface of the metal layer 2122F facing the electrode assembly 23, or on the surface of the metal layer 2122F facing the first conductive part 2121, or simultaneously on both surfaces. The material of the flux layer 2122G can also be selected according to the specific welding object or welding process requirements, for example, it can be a nickel plating layer.

[0124] By including a metal layer 2122F and a flux layer 2122G in the second conductive part 2122, the welding quality of the second conductive part 2122 can be improved, the reliability of the connection can be increased, and the contact resistance can be reduced.

[0125] Please refer to Figures 3-5. According to some embodiments of this application, the electrode assembly 23 includes a first electrode assembly 231 and a second electrode assembly 232. Both the first electrode assembly 231 and the second electrode assembly 232 include a positive electrode tab and a negative electrode tab, respectively. The electrode terminal 212 includes a first electrode terminal 212A and a second electrode terminal 212B. Specifically, the positive electrode tab 2311 of the first electrode assembly 231 and the positive electrode tab 2321 of the second electrode assembly 232 are fixedly connected to the second conductive portion 2122 of the first electrode terminal 212A, and the negative electrode tab 2312 of the first electrode assembly 231 and the negative electrode tab 2322 of the second electrode assembly 232 are fixedly connected to the second conductive portion 2122 of the second electrode terminal 212B, respectively.

[0126] The positive electrode tab refers to the metal conductor that leads out the positive electrode from the electrode assembly 23, and the negative electrode tab refers to the metal conductor that leads out the negative electrode from the electrode assembly 23.

[0127] In some embodiments, the first conductive portion 2121 of the first electrode terminal 212A may be made of materials such as aluminum or aluminum alloy, and the first conductive portion 2121 of the second electrode terminal 212B may be made of materials such as copper or copper alloy.

[0128] By fixing the positive electrode tab 2311 of the first electrode assembly 231 and the positive electrode tab 2321 of the second electrode assembly 232 to the second conductive part 2122 of the first electrode terminal 212A, and fixing the negative electrode tab 2312 of the first electrode assembly 231 and the negative electrode tab 2322 of the second electrode assembly 232 to the second conductive part 2122 of the second electrode terminal 212B, the first electrode terminal 212A forms the positive electrode of the battery cell 20, and the second electrode terminal 212B forms the negative electrode of the battery cell 20.

[0129] Furthermore, as shown in Figures 7-8, 10-11 and 13, in order to improve the connection stability between the first conductive part 2121 and the first wall 211, the top 2121C of the first conductive part 2121 located outside the battery cell can be connected to the first wall 211 through the second insulating member 2132.

[0130] The second insulating member 2132 can insulate the first conductive part 2121 and the first wall 211 from each other.

[0131] In some examples, the second insulating member 2132 corresponding to the first electrode terminal 212A is made of conductive polyphenylene sulfide, and the housing 22 is made of aluminum, so that there is a certain resistance between the first electrode terminal 212A and the first wall 211, reducing the potential difference between the first electrode terminal 212A and the housing 22, preventing electro-corrosion of the first wall 211 and the housing, and improving the quality and service life of the battery cell.

[0132] In some examples, the second insulating member 2132 corresponding to the second electrode terminal 212A may be made of insulating polyphenylene sulfide, the sealing ring 2133 may be made of fluororubber, and the first insulating member 2131 may be made of polypropylene.

[0133] Understandably, housing assembly 21 may also include components such as a pressure relief valve.

[0134] By providing two electrode assemblies 23 connected to the electrode terminals 212 inside the housing 22, the capacity and energy density of a single battery cell 20, as well as the overall charge and discharge performance of the battery cell 20, can be improved.

[0135] According to some embodiments of this application, the base metal of the first conductive portion 2121 of the second electrode terminal 212B is different from that of the second conductive portion 2122 of the second electrode terminal 212B.

[0136] The base metal refers to the main component metal in a material (such as an alloy or composite material), for example, a metallic element with a mass fraction greater than 50%. The first conductive part 2121 or the second conductive part 2122 is an alloy material with specific properties, which can be made by adding one or more alloying elements to the base metal and then processing it through processes such as smelting, casting, and extrusion. Different base metal materials will have varying properties.

[0137] The base metal of the first conductive part 2121 of the second electrode terminal 212B and the second conductive part 2122 of the second electrode terminal 212B are different, which can better meet the welding requirements caused by different welding objects and improve the quality of the connection.

[0138] According to some embodiments of this application, the base metal of the first conductive portion 2121 of the second electrode terminal 212B is aluminum or steel, and the base metal of the second conductive portion 2122 of the second electrode terminal 212B is copper.

[0139] In some embodiments, the base metal of the second conductive portion 2122 of the second electrode terminal 212B is the same material as that of the negative electrode tab, both being copper. The base metal of the first conductive portion 2121 of the second electrode terminal 212B can be the same material as that of the casing 22 or the first wall 211 of the battery cell 20, both being steel or aluminum.

[0140] By making the base metal of the first conductive part 2121 of the second electrode terminal 212B aluminum or steel, and the base metal of the second conductive part 2122 of the second electrode terminal 212B copper, it is possible to better adapt to subsequent welding processes and improve the overall quality of the battery.

[0141] According to some embodiments of this application, the base metal of the first conductive portion 2121 of the first electrode terminal 212A and the second conductive portion 2122 of the first electrode terminal 212A is the same.

[0142] The first conductive portion 2121 of the first electrode terminal 212A and the second conductive portion 2122 of the first electrode terminal 212A have the same base metal, indicating that the first conductive portion 2121 and the second conductive portion 2122 of the first electrode terminal 212A can use the same base metal material.

[0143] By making the base metal of the first conductive portion 2121 of the first electrode terminal 212A the same as that of the second conductive portion 2122 of the first electrode terminal 212A, good welding performance is achieved between the first conductive portion 2121 and the second conductive portion 2122 of the first electrode terminal 212A.

[0144] According to some embodiments of this application, the base metal of the first conductive portion 2121 and the second conductive portion 2122 of the first electrode terminal 212A is aluminum.

[0145] In some embodiments, the base metal of the first conductive portion 2121 and the second conductive portion 2122 of the first electrode terminal 212A is the same as the material of the positive electrode tab, which is aluminum.

[0146] By using aluminum as the base metal for the first conductive portion 2121 and the second conductive portion 2122 of the first electrode terminal 212A, good welding performance can be achieved between the first electrode terminal 212A and the positive electrode tab, thereby improving the welding quality between the first electrode terminal 212A and the positive electrode tab.

[0147] This application also provides a battery 100, as shown in FIG2, which includes the battery cell 20 in the above embodiments.

[0148] It is understood that the battery 100 provided in this application, by using any of the aforementioned battery cells 20, has all the beneficial effects of the aforementioned battery cells 20, which will not be elaborated here.

[0149] An embodiment of the third aspect of this application provides an electrical device that includes the battery 100 described in the above embodiments, the battery 100 being used to provide electrical energy.

[0150] Electrical devices include vehicles (such as cars, electric vehicles, ships, spacecraft, etc.), display devices (such as mobile phones, tablets, laptops, etc.), electric toys, power tools, etc.

[0151] It is understood that the electrical device provided in this application, by using any of the aforementioned battery cells 20, has all the beneficial effects of the aforementioned battery cells 20, which will not be elaborated here.

[0152] An embodiment of the fourth aspect of this application provides an energy storage device, which includes the battery 100 in the above embodiments, the battery 100 being used for energy storage.

[0153] Energy storage devices can include, but are not limited to, centralized energy storage devices (such as containerized energy storage devices), distributed energy storage devices, mobile energy storage devices, wearable energy storage devices, and so on.

[0154] It is understood that the energy storage device provided in this application, by using any of the aforementioned battery cells 20, has all the beneficial effects of the aforementioned battery cells 20, which will not be elaborated here.

[0155] The battery cell of this application will be further described below with reference to a specific embodiment.

[0156] The battery cell 20 provided in this application embodiment includes a housing assembly 21, a casing 22, and an electrode assembly 23.

[0157] The housing 22 has an opening for receiving the electrode assembly 23, and the outer casing assembly 21 is connected to the housing 22 to close its opening.

[0158] The housing assembly 21 includes a first wall 211, a mounting hole 2111, an electrode terminal 212, a first insulating element 2131, a second insulating element 2132, and a sealing ring 2133.

[0159] The first wall 211 includes a first portion 211A, a second portion 211C, and a transition portion 212B connecting the first portion 211A and the second portion 211C. The second portion 211C is offset relative to the first portion 211A in a direction away from the electrode assembly 23, and a mounting hole 2111 is formed in the second portion.

[0160] The electrode assembly 23 includes a first electrode assembly 231 and a second electrode assembly 232. Both the first electrode assembly 231 and the second electrode assembly 232 include a positive electrode tab and a negative electrode tab, respectively.

[0161] Electrode terminal 212 includes a first electrode terminal 212A and a second electrode terminal 212B. Each electrode terminal includes a first conductive portion 2121 and a second conductive portion 2122. The first conductive portion 2121 has a plurality of spaced first protrusions 2121A on the side facing the second conductive portion 2122. Each first protrusion 2121A has a second protrusion 2121B on the side facing the second conductive portion 2122. The second conductive portion 2122 has a through hole 2122C corresponding to the second protrusion 2121B. The first protrusion 2121A passes through the mounting hole 2111 and is inserted into the through hole 2122C of the second conductive portion 2122 through the second protrusion 2121B.

[0162] The positive electrode tab 2311 of the first electrode assembly 231 and the positive electrode tab 2321 of the second electrode assembly 232 are respectively fixedly connected to the second conductive part 2122 of the first electrode terminal 212A. The negative electrode tab 2312 of the first electrode assembly 231 and the negative electrode tab 2322 of the second electrode assembly 232 are respectively fixedly connected to the second conductive part 2122 of the second electrode terminal 212B.

[0163] The first insulating member 2131 is disposed on the side of the first wall 211 facing the electrode assembly 23. The top 2121C of the first conductive part 2121 is connected to the surface of the first wall 211 away from the electrode assembly 23 through the second insulating member 2132. The sealing ring 2133 is sandwiched between the first wall 211 and the first conductive part 2121.

[0164] The upper surface of the second conductive part 2122 abuts against the lower surface of the first insulating member 2131. The second conductive part 2122 is connected to the tab 23a to form a connecting part 24a. Along the thickness direction of the first wall 211, the orthographic projection of the connecting part 24a at least partially overlaps with the orthographic projection of the first conductive part 2121.

[0165] In this embodiment, along the thickness direction of the first wall 211, the orthographic projection of the connection portion 24a formed by the connection between the second conductive portion 2122 and the tab 23a at least partially overlaps with the orthographic projection of the first conductive portion 2121. This can improve the welding penetration of the electrode terminal 212 and the tab 23a, and provide a larger connection area for the tab 23a, thereby improving the overcurrent capacity and connection reliability of the tab 23a and the electrode terminal 212, reducing contact resistance, reducing overcurrent heat generation, and the electrode terminal 212 can also provide strength support for the weak area of ​​the first wall 211. Furthermore, it can save the internal arrangement space of the battery cell, which is beneficial to improving the energy density of the battery cell.

[0166] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not 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 modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A single battery cell, comprising: Electrode assemblies, including tabs; and The housing assembly includes a first wall and electrode terminals, the first wall including mounting holes; The electrode terminal includes a first conductive part and a second conductive part fixedly connected. The second conductive part is at least partially located on the side of the first wall facing the electrode assembly. The first conductive part is at least partially inserted through the mounting hole. The second conductive part is connected to the tab and forms a connecting part. Along the thickness direction of the first wall, the orthographic projection of the connecting part at least partially overlaps with the orthographic projection of the first conductive part.

2. The battery cell according to claim 1, wherein, The first conductive part has a plurality of spaced first protrusions on the side facing the second conductive part. The first protrusions at least partially pass through the mounting hole and are fixedly connected to the second conductive part.

3. The battery cell according to claim 2, wherein, The housing assembly also includes: A sealing ring is sandwiched between the first wall and the first conductive part, and the sealing ring is at least partially used to seal the gap between the first protrusion and the mounting hole.

4. The battery cell according to claim 3, wherein, The housing assembly also includes: A first insulating element is disposed on the side of the first wall facing the electrode assembly; The second conductive part abuts against the side of the first insulating member away from the first wall, and the orthographic projection of the sealing ring on the first wall at least partially overlaps with the orthographic projection of the second conductive part on the first wall.

5. The battery cell according to any one of claims 2-4, wherein, The side of the first protrusion facing the second conductive portion has at least one second protrusion. The second conductive portion has a through hole or a blind hole corresponding to the second protrusion, and the second protrusion is at least partially disposed in the through hole or the blind hole.

6. The battery cell according to claim 5, wherein, The second protrusion and the second conductive part are fixedly connected by riveting or welding.

7. The battery cell according to any one of claims 2-6, wherein, The second conductive portion includes a first surface and a second surface opposite to each other along the thickness direction. The first surface faces the first conductive portion, and the first surface has a third protrusion corresponding to at least one of the first protrusions. The third protrusion is used to be fixedly connected to the corresponding first protrusion.

8. The battery cell according to claim 7, wherein, The second surface has a groove located on the back side of the third protrusion.

9. The battery cell according to any one of claims 1-8, wherein, The first wall includes a first part, a second part, and a transition portion connecting the first part and the second part; The second portion is offset away from the first portion in a direction away from the electrode assembly, and the mounting hole is opened in the second portion, and the outer contour of the orthographic projection of the second conductive part on the first wall falls within the range of the outer contour of the second portion.

10. The battery cell according to any one of claims 2-9, wherein, The connection area between the second conductive part and the first protrusion is spaced apart from the connection part.

11. The battery cell according to any one of claims 2-4, wherein, The first conductive part includes a plurality of sub-conductive parts, and an insulating part is sandwiched between two adjacent sub-conductive parts. The side of the sub-conductive part facing the second conductive part has the first protrusion.

12. The battery cell according to any one of claims 1-11, wherein, The battery cell also includes a fixing member disposed on the surface of the first wall away from the electrode assembly, and is used to fix the first conductive part.

13. The battery cell according to any one of claims 1-12, wherein, The second conductive portion includes a metal layer and a flux layer, wherein the flux layer is located on the side surface of the metal layer facing the electrode assembly, and / or on the side surface of the metal layer facing the first conductive portion.

14. The battery cell according to any one of claims 1-13, wherein, The electrode assembly includes a first electrode assembly and a second electrode assembly; Both the first electrode assembly and the second electrode assembly include a positive electrode tab and a negative electrode tab, and the electrode terminals include a first electrode terminal and a second electrode terminal; Furthermore, the positive electrode tabs of the first electrode assembly and the second electrode assembly are respectively fixedly connected to the second conductive portion of the first electrode terminal, and the negative electrode tabs of the first electrode assembly and the second electrode assembly are respectively fixedly connected to the second conductive portion of the second electrode terminal.

15. The battery cell according to claim 14, wherein, The first conductive portion of the second electrode terminal is different from the base metal of the second conductive portion of the second electrode terminal.

16. The battery cell according to claim 15, wherein, The base metal of the first conductive part of the second electrode terminal is aluminum or steel, and the base metal of the second conductive part of the second electrode terminal is copper.

17. The battery cell according to claim 14, wherein, The first conductive portion of the first electrode terminal has the same base metal as the second conductive portion of the first electrode terminal.

18. The battery cell according to claim 17, wherein, The base metal of the first conductive portion and the second conductive portion of the first electrode terminal is aluminum.

19. A battery comprising a battery cell as claimed in any one of claims 1-18.

20. An electrical device comprising a battery as claimed in claim 19, the battery being used to provide electrical energy.

21. An energy storage device comprising a battery as described in claim 19, the battery being used for energy storage.

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