Battery cell, battery device and electric device

Abstract

Provided in the embodiments of the present application are a battery cell, a battery device and an electric device. The battery cell comprises a casing, an electrode assembly, an electrode terminal and a sealing component, wherein the casing comprises a first wall and an accommodating cavity; the electrode assembly is arranged in the accommodating cavity, and the electrode assembly comprises a tab; the electrode terminal is arranged on the first wall and configured to electrically connect to the tab; the electrode terminal comprises a first connecting portion, the first connecting portion being at least partially arranged on the side of the first wall facing the electrode assembly; the sealing component is at least partially located between the first connecting portion and the first wall; and the first connecting portion comprises a thickened portion and a main body portion, the thickened portion protruding from the side of the main body portion facing the electrode assembly, and the thickened portion being electrically connected to the tab via a first weld mark. By providing the thickened portion on the first connecting portion, the distance between the first weld mark and the sealing component in a first direction can be increased, thereby reducing the risk of thermal damage to the sealing component, and prolonging the service life of the battery cell.

Description

Battery cells, battery packs and electrical devices Technical Field

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

[0002] In recent years, with the rapid development of new energy technologies, new energy vehicles have become increasingly widely used and are gradually replacing traditional fuel vehicles, becoming one of the mainstream modes of transportation. As the power source of new energy vehicles, the power battery is one of their core components; therefore, the safety performance of the power battery has become a key focus of attention.

[0003] In the development of battery technology, improving the lifespan 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, which can improve the service life of the battery cell by enhancing the reliability of the internal sealing components.

[0005] In a first aspect, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, electrode terminals, and a sealing component. The casing includes a first wall and a receiving cavity, and the electrode assembly is placed in the receiving cavity. The electrode assembly includes a tab. The electrode terminal is disposed on the first wall and is used for electrical connection with the tab. The electrode terminal includes a first connecting portion, which is at least partially disposed on the side of the first wall facing the electrode assembly. The sealing component is at least partially located between the first connecting portion and the first wall. The first connecting portion includes a thickened portion and a main body portion. The thickened portion protrudes from the side of the main body portion facing the electrode assembly, and the thickened portion is electrically connected to the tab via a first solder mark.

[0006] In the above-described embodiments, the electrode terminals are electrically connected to the tabs via a first solder mark. During the welding process between the electrode terminals and the tabs or adapter components, a significant amount of heat is generated. Adding a thickened portion to the first connection increases the distance between the first solder mark and the sealing component along the first direction, and also increases the heat dissipation area of ​​the first connection, thereby reducing the risk of the sealing component being burned, improving its reliability, and ultimately extending the battery cell's lifespan. Furthermore, the bottom of the electrode terminals is locally thickened, which saves material and provides space for other components within the battery cell.

[0007] In some embodiments, the size of the thickened portion is equal to the size of the main portion along the width direction of the first wall.

[0008] In the above embodiment, the thickened portion can extend along the width direction of the first wall. The thickened portion is electrically connected to the electrode tab through the first solder mark, which can increase the area of ​​the first solder mark and effectively increase the current-carrying area to meet the requirements of large current overcurrent.

[0009] In some embodiments, the size of the thickened portion along the first direction is less than 1 mm. By limiting the size of the thickened portion along the first direction, the space occupied by the thickened portion along the first direction can be reduced, thereby increasing the energy density while preventing burns to the sealing component.

[0010] In some embodiments, the battery cell further includes an adapter component that connects the tab and the thickened portion, and the adapter component is connected to the thickened portion via a first solder mark.

[0011] In the above embodiment, the electrode terminal is electrically connected to the electrode tab through an adapter component. The first solder mark is used to connect the electrode terminal and the adapter component. The adapter component can solve the problem of difficult welding between the electrode tab and the electrode terminal, and effectively improve the stability of the electrical connection between the electrode terminal and the electrode tab.

[0012] In some embodiments, the adapter includes a tab connection area and a terminal connection area. The terminal connection area is connected to the electrode terminal via a first solder mark, and the tab connection area is connected to the tab. Along a first direction, the size of the tab connection area is larger than the size of the terminal connection area. The tab connection area and the terminal connection area together form a groove. The groove is located on the side surface of the adapter away from the electrode assembly. The electrode terminal is at least partially accommodated in the groove. The first direction is the thickness direction of the first wall.

[0013] In the above embodiment, a groove is provided on the side surface of the adapter component away from the component. The thickened part of the first connecting part can be nested with the groove of the adapter component, which reduces the space occupied by the first connecting part and the adapter component along the first direction and improves the capacity density of the battery cell. In addition, the nested structure of the thickened part and the adapter component is beneficial to the positioning during welding and also beneficial to the welding of the electrode terminals to the adapter component.

[0014] In some embodiments, the depth of the groove along the first direction is less than 1 mm. The maximum depth of the groove is not greater than the maximum dimension of the thickened portion of the first connecting part exceeding the maximum dimension of the main body, thereby improving the connection stability between the adapter and the first connecting part.

[0015] In some embodiments, a gap is provided between the main body and the electrode connection area along a first direction.

[0016] In the above embodiment, the gap between the main body and the electrode connection area can reduce the situation where the connection interface between the thickened part and the terminal connection area has a gap due to processing errors, resulting in unstable welding, and improve the connection stability between the adapter and the first connection part.

[0017] In some embodiments, the terminal connection area is disposed opposite to the thickened portion, and in the same projection plane perpendicular to the first direction, the orthographic projection of the thickened portion falls completely into the orthographic projection of the groove.

[0018] The above-described embodiments can reduce the occurrence of metal wires caused by interference between the thickened portion and the terminal connection area, thereby reducing internal short circuits caused by metal wires and improving the safety of the battery cell.

[0019] In some embodiments, the adapter further includes a second solder mark located in the tab connection area, and the adapter is connected to the tab via the second solder mark. The connection between the adapter and the tab via the second solder mark allows for electrical connection between the electrode terminal and the tab through both the second solder mark and the first solder mark on the adapter.

[0020] In some embodiments, the terminal connection area at least partially overlaps with the second solder mark along the width direction of the first wall.

[0021] In the above embodiment, the second solder mark extends to the vicinity of the terminal connection area, and the straight line along the second direction can intersect the terminal connection area and the second solder mark simultaneously, which can increase the area of ​​the second solder mark and increase the current flow area.

[0022] In some embodiments, the main body portion at least partially overlaps with the second solder mark along the first direction.

[0023] In the above embodiment, the second solder mark can extend to overlap with the main body, thereby increasing the area of ​​the second solder mark and increasing the flow area.

[0024] In some embodiments, the orthographic projection of the sealing component and the orthographic projection of the first solder mark do not overlap in the same projection plane perpendicular to the first direction.

[0025] In the above embodiment, the electrode terminal is electrically connected to the tab through the first solder mark. The electrode terminal generates a lot of heat during the welding process with the tab or the adapter. By offsetting the orthographic projection of the sealing component and the first solder mark in the same projection plane perpendicular to the first direction, the risk of the sealing component being burned can be reduced and the stability of the battery cell can be improved.

[0026] In some embodiments, the orthographic projection of the sealing member is annular in the same projection plane perpendicular to the first direction and is located outside the orthographic projection of the first solder mark.

[0027] The above-described embodiment defines the relative positions of the orthographic projection of the sealing component and the orthographic projection of the first solder mark within the same projection plane perpendicular to the first direction. This ensures the maximization of the area of ​​the first solder mark, effectively increasing the current-carrying area and meeting the requirements of high-current overcurrent. At the same time, the orthographic projection of the sealing component is staggered from the orthographic projection of the first solder mark, which reduces the risk of the sealing component being burned, improves the reliability of the sealing component, and thus increases the service life of the battery cell.

[0028] In some embodiments, the electrode terminal further includes a second connection portion and a transition portion connecting the first connection portion and the second connection portion, the second connection portion being located on the side of the first wall away from the electrode assembly, and the transition portion extending at least partially through the first wall.

[0029] In the above embodiment, the transition portion penetrates the first wall, and the two ends of the transition portion are respectively connected to the first connecting portion and the second connecting portion. The electrode terminal can be fixed to the first wall through the first connecting portion, the transition portion and the second connecting portion.

[0030] In some embodiments, the transition portion includes a first sub-transition portion and a second sub-transition portion. The first sub-transition portion penetrates through the first wall, and the second sub-transition portion penetrates through the second connecting portion. In a cross-section perpendicular to the first direction, the cross-sectional area of ​​the first sub-transition portion is larger than the cross-sectional area of ​​the second sub-transition portion.

[0031] In the above embodiment, the second connecting portion surrounds the second sub-transition portion, and the cross-sectional area of ​​the first sub-transition portion is larger than the cross-sectional area of ​​the second sub-transition portion. The second connecting portion can connect with the first sub-transition portion through the surface of the first sub-transition portion extending beyond the second sub-transition portion, thereby increasing the connection area between the second connecting portion and the transition portion.

[0032] In some embodiments, the surface of the first sub-transition portion away from the first connecting portion abuts against the second connecting portion, thereby achieving a fixed connection with the transition portion.

[0033] In some embodiments, the area of ​​the minimum cross section of the first sub-transition portion perpendicular to the first direction is S1, and the area of ​​the minimum cross section of the second sub-transition portion perpendicular to the first direction is S2. S1 and S2 satisfy: 1.2≤S1 / S2≤3.

[0034] In the above embodiment, the area ratio of the minimum cross-section of the first sub-transition portion and the second sub-transition portion perpendicular to the first direction is limited. Setting S1 / S2 to be greater than or equal to 1.2 can provide sufficient connection area between the second connecting portion and the first sub-transition portion, thereby improving the current carrying capacity of the electrode terminal. Setting S1 / S2 to be less than or equal to 3 can reduce the maximum size difference between the first sub-transition portion and the second sub-transition portion, so that the second connecting portion can maintain stable contact with the second terminal portion under the constraint of the second sub-transition portion, thereby improving the current carrying capacity and reducing the risk of connection failure between the second sub-transition portion and the second connecting portion.

[0035] In some embodiments, the second sub-transition portion is connected to the second connecting portion, and at least a portion of the second sub-transition portion is located on the side of the second connecting portion opposite to the electrode assembly along a first direction. In this way, the second sub-transition portion can press the second connecting portion against the first wall and provide a higher connection strength.

[0036] In some embodiments, the second connection portion includes a third solder mark for connection with a busbar component, wherein the orthographic projection of the third solder mark at least partially overlaps with the orthographic projection of the first sub-transition portion on the same projection plane along the first direction. This can shorten the conductive path between the first sub-transition portion and the third solder mark, reduce resistance, lower the temperature rise of the electrode terminals during overcurrent, improve the cycle performance of the battery cell, and reduce the risk of thermal runaway of the battery cell.

[0037] In some embodiments, on the same projection plane along the first direction, the orthographic projection of the third solder mark falls completely within the orthographic projection range of the first sub-transition portion. Embodiments of this application can further shorten the conductive path between the first sub-transition portion and the third solder mark, reduce resistance, lower the temperature rise of the electrode terminals during overcurrent, improve the cycle performance of the battery cell, and reduce the risk of thermal runaway in the battery cell. When welding the second connection portion and the busbar component, even if the second connection portion is welded through, the first sub-transition portion can still prevent the molten pool from melting, reducing the risk of other components of the battery cell being melted through and improving the reliability of the battery cell.

[0038] In some embodiments, the third solder mark extends at least partially to the first sub-transition portion along the first direction. In this embodiment, a portion of the current in the first sub-transition portion can be conducted to the busbar through the third solder mark, which can further reduce resistance, reduce the temperature rise of the electrode terminals during overcurrent, improve the cycle performance of the battery cell, and reduce the risk of thermal runaway of the battery cell.

[0039] Secondly, embodiments of this application provide a battery device including a battery cell of any of the above embodiments.

[0040] In some embodiments, the battery device further includes a busbar component connected to the electrode terminals via a third solder mark.

[0041] Thirdly, embodiments of this application also provide an electrical device, including a battery device according to any of the above embodiments, the battery device being used to provide electrical energy.

[0042] 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, specific embodiments of this application are given below. Attached Figure Description

[0043] 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.

[0044] Figure 1 is a structural schematic diagram of a vehicle disclosed in an embodiment of this application;

[0045] Figure 2 is an exploded structural diagram of a battery pack disclosed in an embodiment of this application;

[0046] Figure 3 is a schematic diagram of the structure of a battery cell disclosed in an embodiment of this application;

[0047] Figure 4 is a detailed view of the electrode terminals of a battery cell disclosed in an embodiment of this application;

[0048] Figure 5 is a schematic diagram of the bottom structure of the electrode terminals of a battery cell disclosed in an embodiment of this application;

[0049] Figure 6 is a schematic diagram of the bottom structure of the electrode terminals of a battery cell disclosed in an embodiment of this application;

[0050] Figure 7 is a detailed view of an internal electrode terminal of a battery cell disclosed in an embodiment of this application;

[0051] Figure 8 is a schematic diagram of the structure of a battery cell adapter component disclosed in an embodiment of this application;

[0052] Figure 9 is a schematic diagram of the orthographic projection of the first solder mark and sealing component inside a battery cell in an embodiment of this application onto the first wall;

[0053] Figure 10 is a schematic diagram of the orthographic projection of the second solder mark and terminal connection area inside a battery cell disclosed in an embodiment of this application onto the first wall;

[0054] Figure 11 is a detailed view of the electrode terminals of a battery cell disclosed in an embodiment of this application;

[0055] Figure 12 is a schematic diagram of the connection between a battery cell and a busbar component disclosed in an embodiment of this application;

[0056] Figure 13 is a schematic diagram of the connection between a battery cell and a busbar component disclosed in an embodiment of this application;

[0057] Figure 14 is a simplified schematic diagram of a battery device disclosed in an embodiment of this application.

[0058] The accompanying drawings are not drawn to scale.

[0059] Marking Explanation: 1000, Vehicle; 100, Battery Unit; 200, Controller; 300, Motor; 400, Battery Module; 10, Top Cover; 30, Housing; 20, Battery Cell; 21, Housing; 22, End Cap; 26, Electrode Terminal; 23, Electrode Assembly; 231, Tab; 25, Outer Shell; 251, First Wall; 24, Sealing Component; 29, Pressure Relief Component; 261, First Connecting Part; 2611, Thickened Part; 2612, Main Body Part; 262, Second Connecting Part; 263, Transition Part; 2631, First Sub-Transition Part; 2632, Second Sub-Transition Part; 27, Adapter Component; 271, Tab Connection Area; 272, Terminal Connection Area; 28, Busbar Component;

[0060] W1, first solder mark; W2, second solder mark; W3, third solder mark;

[0061] X, the first direction. Detailed Implementation

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0071] The battery cell conducts current from the inside to the outside through electrode terminals. These terminals can be directly connected to the tabs or electrically connected via adapters. Furthermore, a sealing component is installed between the battery cell casing and the electrode terminals, surrounding the terminals and playing a significant role in ensuring the airtightness of the battery cell casing. In both methods, the electrode terminals can be electrically connected to the tabs by welding, a process that releases heat at the solder joint. Additionally, the charging and discharging of the battery cell also involves current flow through these solder joints, a process that also generates heat. The heat released during welding and the heat generated by current flow can easily damage the sealing component, reducing its reliability and ultimately shortening the battery cell's lifespan.

[0072] To address the aforementioned issues, this application provides a battery cell comprising a casing, an electrode assembly, electrode terminals, and a sealing component. The casing includes a receiving cavity and a first wall; the electrode assembly is located within the receiving cavity and includes tabs; the electrode terminals are disposed on the first wall and are used for electrical connection with the tabs. Each electrode terminal includes a first connecting portion, at least partially disposed on the side of the first wall facing the electrode assembly; the sealing component is at least partially located between the first connecting portion and the first wall; the first connecting portion includes a thickened portion and a main body portion, the thickened portion protruding from the side of the main body portion facing the electrode assembly, and the thickened portion is electrically connected to the tabs via a first solder mark. By adding a thickened portion to the first connecting portion, the distance between the first solder mark and the sealing component along a first direction can be increased, and the heat dissipation area of ​​the first connecting portion can be increased, reducing the risk of the sealing component being burned and improving the service life of the battery cell.

[0073] 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.

[0074] 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.

[0075] Please refer to Figure 1, which is a structural schematic diagram of a vehicle 1000 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 startup, navigation, and driving.

[0076] 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.

[0077] Please refer to Figure 2, which is an exploded view of a battery device 100 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 accommodating 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.

[0078] 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 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 a casing. Alternatively, 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, which is then housed within a casing. 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 the multiple battery cells 20.

[0079] Referring to FIG3, FIG3 is a schematic diagram of the structure of a battery cell 20 according to some embodiments of the present application. In some embodiments, the battery cell 20 includes a housing 20 and an electrode assembly 23 housed within the housing 20.

[0080] In some embodiments, the outer casing 20 may be a steel casing, an aluminum casing, or a composite metal casing (such as a copper-aluminum composite casing).

[0081] The outer shell 20 may be a hollow structure, with an internal cavity for accommodating the electrode assembly 23 and the electrolyte.

[0082] In some embodiments, the outer casing 25 of the battery cell 20 is a cylindrical casing, a square casing, a prismatic casing, or a casing of other shapes.

[0083] In some embodiments, the housing 25 includes a housing 2121 and an end cap 22, the housing 21 having an opening, and the end cap 22 being connected to the housing 21 and covering the opening;

[0084] The housing 21 is a component used to fit the end cap 22 to form an internal cavity of the battery cell 20, which can be used to accommodate the electrode assembly 23, electrolyte and other components.

[0085] The housing 21 and the end cap 22 can be separate components. For example, an opening can be provided on the housing 21, and the end cap 22 can be used to close the opening to form an internal cavity for the battery cell 20.

[0086] The housing 21 can be of various shapes and sizes, such as cuboid or cylindrical. Specifically, the shape of the housing 21 can be determined according to the specific shape and size of the electrode assembly 23. The housing 21 can be made of various materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0087] The shape of the end cap 22 can be adapted to the shape of the housing 21 to fit the housing 21. The material of the end cap 22 can be the same as or different from the material of the housing 21. Optionally, the end cap 22 can be made of a material with a certain hardness and strength (such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.), so that the end cap 22 is not easily deformed when subjected to compression and impact, so that the battery cell 20 can have higher structural strength and improve reliability.

[0088] The end cap 22 is connected to the housing 21 by welding, bonding, snap-fitting or other means.

[0089] The housing 21 may be open at one end or open at both ends. In some examples, the housing 21 may be a structure with an opening on one side, and one end cap 22 is provided to cover the housing 21. In other examples, the housing 21 may also be a structure with openings on both sides, and two end caps 22 are provided, with the two end caps 22 respectively covering the two openings of the housing 21.

[0090] The end cap 22 may be provided with functional components such as electrode terminals 26. The electrode terminals 26 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 end cap 22 may also be provided with a pressure relief component 29 for releasing internal pressure when the internal pressure or temperature of the battery cell 20 reaches a threshold. The end cap 22 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 member may also be provided on the inner side of the end cap 22. The insulating member can be used to isolate the electrical connection components within the housing 21 from the end cap 22 to reduce the risk of short circuits. For example, the insulating member may be plastic, rubber, etc.

[0091] The electrode assembly 23 includes a positive electrode, a negative electrode, and a separator, with the separator positioned between the negative and positive electrodes. During the charging and discharging process of the battery cell 20, active ions (such as lithium ions) repeatedly insert and extract between the positive and negative electrodes. The separator, positioned between the positive and negative electrodes, serves to prevent short circuits between the electrodes while allowing active ions to pass through.

[0092] In some embodiments, the positive electrode may be a positive electrode sheet, which may include a positive electrode current collector and a positive electrode active material disposed on at least one surface of the positive electrode current collector. As an example, the positive electrode current collector has two surfaces opposite each other in its own thickness direction, and the positive electrode active material is disposed on either or both of the two opposite surfaces of the positive electrode current collector.

[0093] As an example, the positive current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (aluminum, aluminum alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0094] As an example, the positive electrode active material may include at least one of the following materials: lithium phosphate, lithium transition metal oxide, and their respective modified compounds. However, this application is not limited to these materials, and other conventional materials that can be used as positive electrode active materials for batteries may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate include, but are not limited to, at least one of lithium iron phosphate (such as LiFePO4 (also referred to as LFP)), lithium iron phosphate and carbon composites, lithium manganese phosphate (such as LiMnPO4), lithium manganese phosphate and carbon composites, lithium manganese iron phosphate, and lithium manganese iron phosphate and carbon composites. Examples of lithium transition metal oxides may include, but are not limited to, lithium cobalt oxides (such as LiCoO2), lithium nickel oxides (such as LiNiO2), lithium manganese oxides (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxides, lithium manganese cobalt oxides, lithium nickel manganese oxides, lithium nickel cobalt manganese oxides (such as LiNi1 / 3Co1 / 3Mn1 / 3O2 (also abbreviated as NCM333), LiNi0.5Co0.2Mn0.3O2 (also abbreviated as NCM523), LiNi0.5Co The following are included: 0.25Mn0.25O2 (also known as NCM211), LiNi0.6Co0.2Mn0.2O2 (also known as NCM622), LiNi0.8Co0.1Mn0.1O2 (also known as NCM811), lithium nickel cobalt aluminum oxides (such as LiNi0.8Co0.15Al0.05O2), and their modified compounds. Modified compounds refer to substances obtained by doping or coating, etc., based on the above-mentioned materials.

[0095] In some embodiments, the positive electrode includes a positive tab. Exemplarily, at least a portion of the positive tab is not provided with active material.

[0096] In some embodiments, the negative electrode may be a negative electrode sheet, which may include a negative electrode current collector. The negative electrode sheet may include a negative electrode current collector and a negative electrode active material disposed on at least one surface of the negative electrode current collector.

[0097] As an example, the negative electrode current collector has two surfaces opposite each other in its own thickness direction, and the negative electrode active material is disposed on either or both of the two opposite surfaces of the negative electrode current collector.

[0098] As an example, the negative electrode current collector can be a metal foil, a conductive polymer material, a carbon material, or a composite current collector. For example, as a metal foil, pure metals, alloys, or surface-treated metals can be used, including but not limited to stainless steel, copper, aluminum, nickel, nickel alloys, titanium, or silver. The composite current collector may include a polymer material substrate and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloys, nickel, nickel alloys, titanium, titanium alloys, silver, and silver alloys, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0099] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cell 20. As an example, the negative electrode active material may include at least one of the following materials: artificial graphite, natural graphite, soft carbon, hard carbon, silicon-based materials, tin-based materials, and lithium titanate, etc. Silicon-based materials may be selected from at least one of elemental silicon, silicon oxide compounds, silicon-carbon composites, silicon-nitrogen composites, and silicon alloys. Tin-based materials may be selected from at least one of elemental tin, tin oxide compounds, and tin alloys. However, this application is not limited to these materials, and other conventional materials that can be used as negative electrode active materials for battery cell 20 may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0100] In some embodiments, the negative electrode sheet includes a negative electrode tab; exemplaryly, at least a portion of the negative electrode tab is not provided with active material.

[0101] In some embodiments, the electrode assembly 23 further includes a separator disposed between the positive and negative electrodes. In some embodiments, the separator is a separator membrane. This application does not impose any particular limitation on the type of separator membrane; any known porous structure separator membrane with good chemical and mechanical stability can be selected. As an example, the main material of the separator membrane can be selected from at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, polyvinylidene fluoride, and ceramic. The separator membrane can be a single-layer film or a multi-layer composite film, without particular limitation. When the separator membrane is a multi-layer composite film, the materials of each layer can be the same or different, without particular limitation. The separator can be a single component located between the positive and negative electrodes, or it can be attached to the surfaces of the positive and negative electrodes. An inorganic particle coating, an organic particle coating, or an organic / inorganic composite coating can also be coated on the surface of the separator membrane. In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, simultaneously serving the functions of ion transport and isolating the positive and negative electrodes.

[0102] In some embodiments, the battery cell 20 also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. This application does not impose specific limitations on the type of electrolyte; it can be selected according to requirements. The electrolyte can be liquid, gel, or solid.

[0103] The electrode assembly 23 can be a wound structure, a stacked structure, or a hybrid structure of wound and stacked.

[0104] In some embodiments, the electrode assembly 23 is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0105] In some embodiments, the electrode assembly 23 is a stacked structure. As an example, multiple positive and negative electrodes can be provided, with multiple positive electrodes and multiple negative electrodes stacked alternately.

[0106] As an example, multiple positive electrode sheets can be provided, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments. As an example, both positive and negative electrode sheets are folded to form multiple stacked folded segments.

[0107] As an example, multiple separators can be provided, each positioned between any adjacent positive or negative electrode plates.

[0108] As an example, the separators can be continuously arranged, either by folding or rolling between any adjacent positive or negative electrode plates.

[0109] In some embodiments, the electrode assembly 23 may be cylindrical, flat, or polygonal in shape.

[0110] In some embodiments, the electrode assembly 23 is provided with tabs 231, which can conduct current from the electrode assembly 23. The tabs 231 include a positive tab and a negative tab.

[0111] In some embodiments, referring to Figures 4-6, Figure 4 is a detailed view of the electrode terminal 26 of a battery cell 20 according to this application, Figure 5 is a schematic diagram of the bottom structure of the electrode terminal of a battery cell disclosed in an embodiment of this application, and Figure 6 is a schematic diagram of the bottom structure of the electrode terminal of a battery cell disclosed in an embodiment of this application. This application provides a battery cell 20, which includes a housing 25, an electrode assembly 23, electrode terminals 26, and a sealing member 24. The housing 25 includes a receiving cavity and has a first wall 251. The electrode assembly 23 is located within the receiving cavity and includes tabs 231. The electrode terminals 26 are disposed on the first wall 251 and electrically connected to the tabs 231. The electrode terminal 26 includes a first connecting portion 261, which is at least partially disposed on the side of the first wall 251 facing the electrode assembly 23; the sealing member 24 is at least partially located between the first connecting portion 261 and the first wall 251; the first connecting portion 261 includes a thickened portion 2611 and a main body portion 2612, the thickened portion 2611 protruding from the side of the main body portion 2612 facing the electrode assembly 23, and the thickened portion 2611 is electrically connected to the tab 231 through a first solder mark W1.

[0112] The housing 25 includes a receiving cavity and has a first wall 251. As an example, the first wall 251 may be an end cap 22 or a wall of the housing 21.

[0113] The electrode assembly 23 is located within the receiving cavity and includes a tab 231, which can be either a positive tab or a negative tab.

[0114] Electrode terminal 26 is disposed on first wall 251. In some examples, electrode lead-out holes are provided in first wall 251. The electrode lead-out holes can penetrate first wall 251 along the thickness direction of first wall 251. The orthographic projection of electrode terminal 26 and the orthographic projection of electrode lead-out holes at least partially overlap.

[0115] As an example, the electrode lead-out holes can be round, square, racetrack-shaped, elliptical, or other shapes.

[0116] In some examples, the electrode terminal 26 is at least partially located on the outside of the first wall 251 and covers the electrode lead-out hole. Alternatively, the electrode terminal 26 may be entirely located on the outside of the first wall 251; alternatively, the electrode terminal 26 may pass through the electrode lead-out hole, with a portion of the electrode terminal 26 located on the side of the first wall 251 facing the electrode assembly 23 and a portion of the electrode terminal 26 located on the side of the first wall 251 away from the electrode assembly 23.

[0117] Electrode terminal 26 is electrically connected to tab 231, and the polarity of electrode terminal 26 corresponds to the polarity of tab 231. In some examples, tab 231 is the positive tab and electrode terminal 26 is the positive terminal; in other examples, tab 231 is the negative tab and electrode terminal 26 is the negative terminal.

[0118] Electrode terminal 26 can be directly connected to tab 231, or indirectly connected to tab 231 through other conductive structures. Electrode terminal 26 can be used to electrically connect to tab 231 and to an external circuit to enable charging or discharging of battery cell 20.

[0119] There may be one or more electrode terminals 26. In some embodiments, there are two electrode terminals 26 with opposite polarities, both disposed on the first wall 251. As an example, the first wall 251 and the electrode terminals 26 may be pre-assembled together and then assembled with the electrode assembly 23 and the housing 21. Optionally, the electrode terminals 26 may be riveted to the first wall 251.

[0120] Electrode terminal 26 includes a first connecting portion 261, which can be electrically connected to tab 231 via a first solder mark W1. The first connecting portion 261 is at least partially located on the side of the first wall 251 facing the electrode assembly 23, i.e., at least a portion of the first connecting portion 261 is located inside the housing 21. The first connecting portion 261 can be directly electrically connected to tab 231 via the first solder mark W1, in which case the first solder mark W1 is located on the surface of the first connecting portion 261 facing the electrode assembly 23; alternatively, the first connecting portion 261 can be electrically connected to tab 231 via other conductive structures. Optionally, the other conductive component can be a transition member 27, in which case the first solder mark W1 is located on the surface of the transition member 27 facing the electrode assembly 23.

[0121] In some embodiments, the electrode terminal 26 is electrically connected to the tab 231 via the adapter 27. In this case, the first connection portion 261 in the electrode terminal 26 is connected to the adapter 27 via the first solder mark W1, and the tab 231 is connected to the adapter 27 via the second solder mark W2. The first solder mark W1 and the second solder mark W2 do not overlap.

[0122] In some embodiments, the electrode terminal 26 includes a first connecting portion 261, a second connecting portion 262, and a transition portion 263. The transition portion 263 is used to connect the first connecting portion 261 and the second connecting portion 262. The transition portion 263 passes through the first wall 251 through the electrode lead-out hole. The first connecting portion 261 is located on the side of the first wall 251 facing the electrode assembly 23, and the second connecting portion 262 is located on the side of the first wall 251 away from the electrode assembly 23. The electrode terminal 26 is fixedly connected to the first wall 251 through the first connecting portion 261 and the second connecting portion 262.

[0123] The sealing component 24 is at least partially disposed between the first connecting portion 261 and the first wall 251. The sealing component 24 is located between the electrode terminal 26 and the first wall 251, and can play a sealing role at the first through hole to maintain the stability of the internal air pressure of the battery cell 20, while also improving the stability of the connection between the electrode terminal 26 and the first wall 251.

[0124] The first connecting portion 261 includes a thickened portion 2611 and a main body portion 2612. The thickened portion 2611 protrudes from the side of the main body portion 2612 facing the electrode assembly 23. The first connecting portion 261 is partially thickened. Along the thickness direction of the first wall 251, the thickened portion 2611 of the first connecting portion 261 corresponds to the first solder mark W1. In some embodiments, in the same projection plane perpendicular to the thickness direction of the first wall 251, the orthographic projection of the thickened portion 2611 may coincide with the orthographic projection of the first solder mark W1; preferably, the orthographic projection of the thickened portion 2611 can completely cover the orthographic projection of the first solder mark W1.

[0125] According to the battery cell 20 provided in this application embodiment, the electrode terminal 26 is electrically connected to the tab 231 via a first solder mark W1. During the welding process between the electrode terminal 26 and the tab 231 or the adapter component 27, a large amount of heat is generated. Adding a thickened portion 2611 to the first connection portion 261 increases the distance between the first solder mark W1 and the sealing component 24 along the thickness direction of the first wall 251. It also increases the heat dissipation area of ​​the first connection portion 261, thereby reducing the risk of the sealing component 24 being burned, improving the reliability of the sealing component 24, and ultimately increasing the service life of the battery cell 20. Furthermore, the bottom of the electrode terminal 26 is locally thickened, which saves material and provides space for other components within the battery cell 20.

[0126] In some embodiments, please refer to FIG6, which is a schematic diagram of the bottom structure of the electrode terminals of a battery cell disclosed in an embodiment of this application. Along the width direction of the first wall 251, the size of the thickened portion 2611 is equal to the size of the main body portion 2612.

[0127] In the above embodiment, the thickened portion 2611 can extend along the width direction of the first wall 251. The thickened portion 2611 is electrically connected to the tab 231 through the first solder mark W1, which can increase the area of ​​the first solder mark W1, effectively increase the current-carrying area, and meet the requirements of large current overcurrent.

[0128] In some embodiments, the size of the thickened portion is less than 1 mm along the first direction X, where the first direction X is the thickness direction of the first wall 251.

[0129] As an example, the size of the thickened portion 2611 along the first direction X can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or any other value less than 1mm.

[0130] According to the battery cell 20 provided in the embodiments of this application, the size of the thickened portion 2611 along the first direction X is limited, which can reduce the space occupied by the thickened portion 2611 along the first direction X, and improve the energy density while preventing the sealing component 24 from being scalded.

[0131] When the tab 231 is directly welded to the electrode terminal 26, the weld joint of the battery cell 20 will be repeatedly subjected to the stress generated by the charging and discharging of the battery during use. Over time, this may lead to weld fatigue, cracks, and other hidden dangers, affecting the safety and lifespan of the battery cell 20. To solve these problems, an adapter component 27 can be added to the battery cell 20 to connect the electrode terminal 26 and the tab 231. During the use of the battery cell 20, such as when it is subjected to vibration or when the battery cell 20 expands and contracts internally, the adapter component 27 can absorb some of the stress and maintain a stable electrical connection between the tab 231 and the electrode terminal 26.

[0132] In some embodiments, please refer to FIG7, which is a detailed view of the internal electrode terminals of a battery cell disclosed in an embodiment of this application. The battery cell 20 also includes an adapter 27, which connects the tab 231 and the thickened portion 2611. The adapter 27 is connected to the thickened portion 2611 through a first solder mark W1.

[0133] According to the battery cell 20 provided in the embodiments of this application, the electrode terminal 26 is electrically connected to the tab 231 through the adapter 27. The first solder mark W1 is used to connect the electrode terminal 26 and the adapter 27. The adapter 27 can solve the problem of difficult welding between the tab 231 and the electrode terminal 26, and effectively improve the stability of the electrical connection between the electrode terminal 26 and the tab 231.

[0134] In some embodiments, please refer to Figures 7 and 8. Figure 7 is a detailed view of an electrode terminal inside a battery cell disclosed in an embodiment of this application, and Figure 8 is a structural schematic diagram of a battery cell adapter component disclosed in an embodiment of this application. The adapter component 27 includes a tab connection area 271 and a terminal connection area 272. The terminal connection area 272 is connected to the electrode terminal 26 through a first solder mark W1. The tab connection area 271 is connected to the tab 231. Along the first direction X, the thickness of the tab connection area 271 is greater than the thickness of the terminal connection area 272. The tab connection area 271 and the terminal connection area 272 together form a groove. The groove is located on the side surface of the adapter component 27 facing away from the electrode assembly 23. The electrode terminal 26 is at least partially accommodated in the groove.

[0135] The tab connection area 271 of the adapter member 27 can be used to connect with the tab 231, and the terminal connection area 272 can be used to connect with the first connection portion 261 of the electrode terminal 26. The terminal connection area 272 and the thickened portion 2611 are arranged opposite to each other along the first direction X.

[0136] In some embodiments, please refer to FIG9, which is a schematic diagram of the orthographic projection of a first soldering and sealing component within a battery cell on a first wall according to an embodiment of this application. In the same projection plane perpendicular to the first direction X, the orthographic projection of the terminal connection area 272 completely covers the orthographic projection of the first connection portion 261. Furthermore, a groove is provided on the surface of the adapter member 27 facing away from the assembly, allowing the thickened portion 2611 of the first connection portion 261 to form a nested structure with the groove of the adapter member 27.

[0137] The above-described embodiment can reduce the space occupied by the first connecting part 261 and the adapter 27 along the first direction X, thereby increasing the capacity density of the battery cell 20. In addition, the nested structure of the thickened part 2611 and the adapter 27 is beneficial for the positioning of the electrode terminal 26 and also for the welding of the electrode terminal 26 and the adapter 27.

[0138] In some embodiments, the thickened portion 2611 extends beyond the main body portion 2612 by less than 1 mm along the first direction X.

[0139] In some embodiments, the depth of the groove along the first direction X is less than 1 mm.

[0140] As an example, the depth of the groove can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm or any other value less than 1mm.

[0141] When the groove depth is greater than 1mm, the thickness of the terminal connection area 272 is too small, which will affect the welding stability between the adapter component 27 and the electrode terminal 26.

[0142] According to the battery cell 20 provided in the embodiment of this application, limiting the groove depth to less than 1mm can ensure the stability of the connection between the adapter 27 and the electrode terminal 26.

[0143] In some embodiments, please refer to the figure, the main body 2612 and the tab connection area 271 are separated by a gap.

[0144] According to the battery cell 20 provided in the embodiments of this application, the situation where there is a gap at the connection interface between the thickened part 2611 and the terminal connection area 272 due to processing errors and the welding is unstable can be reduced, thereby improving the connection stability of the adapter and the first connection part.

[0145] In some embodiments, please refer to FIG7, the terminal connection area 272 and the thickened portion 2611 are disposed opposite to each other, and in the same projection plane perpendicular to the first direction X, the orthographic projection of the thickened portion 2611 falls completely into the orthographic projection of the terminal connection area 272.

[0146] In the above embodiment, in a plane perpendicular to the first direction X, the orthographic projection of the thickened portion 2611 falls completely within the orthographic projection of the terminal connection area 272. The thickened portion 2611 of the first connection portion 261 can be nested into the terminal connection area 272 of the adapter piece, thereby increasing the energy density of the battery cell 20. In addition, the fact that the orthographic projection of the thickened portion falls completely within the orthographic projection of the terminal connection area can reduce the occurrence of metal wires due to mutual interference between the thickened portion and the terminal connection area, thereby reducing the internal short circuit phenomenon caused by metal wires and improving the safety of the battery cell.

[0147] In some embodiments, the adapter 27 further includes a second solder mark W2 located in the tab connection area 271, and the adapter 27 is connected to the tab 231 through the second solder mark W2.

[0148] The adapter component 27 is connected to the tab 231 via the second solder mark W2, and the adapter component 27 can be connected to the first connecting part 261 via the first solder mark W1. The electrical connection between the electrode terminal 26 and the tab 231 can be achieved through the second solder mark W2 and the first solder mark W1 on the adapter component 27.

[0149] In some embodiments, please refer to FIG10, which is a schematic diagram of the orthographic projection of the second solder mark W2 and the terminal connection area 272 in a battery cell 20 of the present application onto the first wall. Along the width direction of the first wall 251, the terminal connection area 272 and the second solder mark W2 at least partially overlap.

[0150] According to the battery cell 20 provided in the embodiments of this application, the second solder mark W2 can extend along the length direction of the first wall 251 to the terminal connection area 272. Along the width direction of the first wall 251, the terminal connection area 272 and the second solder mark W2 at least partially overlap, which can increase the area of ​​the second solder mark W2 and increase the current flow area.

[0151] In some embodiments, along the first direction X, the main body 2612 at least partially overlaps with the second solder mark W2.

[0152] According to the battery cell 20 provided in the embodiments of this application, the second solder mark W2 can extend to overlap with the main body 2612, thereby increasing the area of ​​the second solder mark W2 and increasing the flow area.

[0153] In some embodiments, please refer to Figure 9, which is a schematic diagram of the orthographic projection of a first solder mark and sealing component within a battery cell on a first wall according to an embodiment of this application. In the same projection plane perpendicular to the first direction X, the orthographic projection of the sealing component 24 and the orthographic projection of the first solder mark W1 do not overlap.

[0154] According to the battery cell 20 provided in the embodiments of this application, the electrode terminal 26 is electrically connected to the tab 231 through the first solder mark W1. The electrode terminal 26 generates a lot of heat during the welding process with the tab 231 or the adapter component 27. By offsetting the orthographic projections of the sealing component 24 and the first solder mark W1 in the same projection plane perpendicular to the first direction X, the risk of the sealing component 24 being burned can be reduced, and the stability of the battery cell 20 can be improved.

[0155] In some embodiments, referring to FIG9, in the same projection plane perpendicular to the first direction X, the orthographic projection of the sealing member 24 is annular and located outside the orthographic projection of the first solder mark W1.

[0156] The orthographic projection of the sealing component 24 is annular and located outside the orthographic projection of the first solder mark W1. It can limit the relative position of the orthographic projection of the sealing component 24 and the orthographic projection of the first solder mark W1 within the same projection plane perpendicular to the first direction X, thereby maximizing the area of ​​the first solder mark W1 and effectively increasing the current-carrying area to meet the requirements of high current overcurrent.

[0157] In the above embodiment, the orthographic projection of the sealing component 24 can surround the orthographic projection of the first solder mark W1, reducing the risk of the sealing component 24 being burned during high current overcurrent and improving the stability of the battery cell 20.

[0158] In some embodiments, please refer to FIG11, which is a detailed view of the electrode terminal of a battery cell disclosed in an embodiment of the present application. The electrode terminal 26 further includes a second connecting portion 262 and a transition portion 263 connecting the first connecting portion 261 and the second connecting portion 262. The second connecting portion 262 is located on the side of the first wall 251 opposite to the electrode assembly 23, and the transition portion 263 at least partially penetrates the first wall 251.

[0159] As an example, the transition portion 263 can be adapted to the shape of the electrode lead-out hole. For example, if the electrode lead-out hole is a circular hole, the transition portion 263 can be a cylindrical structure; if the electrode lead-out hole is a racetrack-shaped hole, the transition portion 263 can be racetrack-shaped.

[0160] The number of transition portions 263 can correspond to the number of electrode leads. In some examples, there are multiple transition portions 263 and multiple electrode leads, with each electrode lead corresponding to one of the multiple transition portions 263; alternatively, there may be only one transition portion 263 and one electrode lead.

[0161] In some embodiments, the first connecting portion 261 may be integrally formed with the transition portion 263. Along the first direction X, the second connecting portion 262 has a first groove on the side facing the transition portion 263, and at least a portion of the transition portion 263 can be accommodated in the first groove. For example, conductive adhesive may be filled into the first groove to achieve adhesive bonding between the transition portion 263 and the second connecting portion 262; alternatively, laser irradiation may be performed on the side of the first groove opposite to the transition portion 263 to achieve laser welding connection between the transition portion 263 and the second connecting portion 262.

[0162] In other embodiments, the first connecting portion 261 may be integrally formed with the transition portion 263; the second connecting portion 262 may be provided with a first through hole, at least a portion of the transition portion 263 is accommodated in the first through hole, and the transition portion 263 is riveted to the second connecting portion 262.

[0163] For example, after the transition portion 263 passes through the first through hole, the transition portion 263 is pressed away from the end of the first connecting portion 261 to realize the flange structure of the transition portion 263, thereby realizing the riveting of the second connecting portion 262 and the transition portion 263.

[0164] In some embodiments, the transition portion 263 points in the direction from the first connecting portion 261 to the second connecting portion 262, and the transition portion 263 does not extend beyond the surface of the second connecting portion 262 away from the first wall 251. In this way, the space occupied by the transition portion 263 along the first direction X can be reduced, and interference with the busbar component 28 can also be reduced.

[0165] In the above embodiment, the transition portion 263 penetrates the first wall 251, and the two ends of the transition portion 263 are respectively connected to the first connecting portion 261 and the second connecting portion 262. The electrode terminal 26 can be fixed to the first wall 251 through the first connecting portion 261, the transition portion 263 and the second connecting portion 262.

[0166] In some embodiments, please refer to FIG11, which is a detailed view of the electrode terminals of a battery cell according to the present application. The transition portion 263 includes a first sub-transition portion 2631 and a second sub-transition portion 2632. The first sub-transition portion 2631 penetrates the first wall 251, and the second sub-transition portion 2632 penetrates the second connecting portion 262. In a cross-section perpendicular to the first direction X, the cross-sectional area of ​​the first sub-transition portion 2631 is larger than the cross-sectional area of ​​the second sub-transition portion 2632.

[0167] In some embodiments, the second connecting portion 262 may be provided with a first through hole, and the second sub-transition portion 2632 may be accommodated in the first through hole and fixedly connected to the second connecting portion 262. For example, conductive adhesive may be provided on the surfaces of the second sub-transition portion 2632 and the second connecting portion 262 that contact each other, and the two can be bonded together by the conductive adhesive; the second sub-transition portion 2632 may also be riveted to the second connecting portion 262.

[0168] In the above embodiment, the second connecting portion 262 surrounds the second sub-transition portion 2632, and the cross-sectional area of ​​the first sub-transition portion 2631 is larger than the cross-sectional area of ​​the second sub-transition portion 2632. At this time, the second connecting portion 262 can be connected to the first sub-transition portion 2631 through the surface of the first sub-transition portion 2631 on the side away from the electrode assembly 23. Such a connection can shorten the path of current conduction from the tab 231 to the second connecting portion 262.

[0169] In some embodiments, referring to FIG11, the surface of the first sub-transition portion 2631 away from the first connecting portion 261 abuts against the second connecting portion 262.

[0170] In some embodiments, riveting the first sub-transition portion 2631 to the second connecting portion 262 can achieve the surface of the first sub-transition portion 2631 away from the first connecting portion 261 abutting against the second connecting portion 262. For example, after the second sub-transition portion 2632 passes through the first through hole, by pressing the end of the second sub-transition portion 2632 away from the first connecting portion 261, a flange structure of the transition portion 263 is achieved, thereby realizing the riveting of the second connecting portion 262 and the transition portion 263.

[0171] In this embodiment of the application, the second sub-transition portion 2632 can constrain the second connection portion 262, thereby maintaining stable contact between the second connection portion 262 and the transition portion 263, thereby improving the overcurrent capacity and reducing the risk of connection failure between the internal transition portion 263 and the second connection portion 262 of the electrode terminal 26.

[0172] In some embodiments, the area of ​​the minimum cross section of the first sub-transition portion 2631 perpendicular to the first direction X is S1, and the area of ​​the minimum cross section of the second sub-transition portion 2632 perpendicular to the first direction X is S2. S1 and S2 satisfy: 1.2≤S1 / S2≤3.

[0173] As an example, S1 / S2 can be 1.2, 1.5, 1.8, 2, 2.4, 2.7, 3, or any value in between.

[0174] In this embodiment, the area ratio of the minimum cross-section of the first sub-transition portion 2631 and the second sub-transition portion 2632 perpendicular to the first direction X is limited. Setting S1 / S2 to be greater than or equal to 1.2 can provide sufficient connection area between the second connecting portion 262 and the first sub-transition portion 2631, thereby improving the current carrying capacity of the electrode terminal 26. Setting S1 / S2 to be less than or equal to 3 can reduce the maximum size difference between the first sub-transition portion 2631 and the second sub-transition portion 2632, so that the second connecting portion 262 can maintain stable contact with the first sub-transition portion 2631 under the constraint of the second sub-transition portion 2632, thereby improving the current carrying capacity and reducing the risk of connection failure between the second sub-transition portion 2632 and the second connecting portion 262.

[0175] In some embodiments, the second sub-transition portion is connected to the second connecting portion, and at least a portion of the second sub-transition portion 2632 is located on the side of the second connecting portion 262 opposite to the electrode assembly 23 along a first direction. Thus, the second sub-transition portion 2632 can press the second connecting portion 262 against the first wall 251 and provide a higher connection strength.

[0176] In some embodiments, please refer to Figures 12 and 13, which are schematic diagrams of the connection between a battery cell 20 and a busbar component 28 disclosed in this application. The second connection portion 262 includes a third solder mark W3 for connection with the busbar component 28. On the same projection plane along the first direction X, the orthographic projection of the third solder mark W3 at least partially overlaps with the orthographic projection of the first sub-transition portion 2631.

[0177] The busbar component 28 can electrically connect two adjacent battery cells 20 through series, parallel, or mixed connection. The busbar component 28 can be a single-layer structure or a multi-layer structure.

[0178] There can be one or more third solder marks W3. The third solder mark W3 can be straight, curved, circular, or other shapes.

[0179] In some examples, the third solder mark W3 may be formed entirely of the busbar 28 and the second connection 262. For example, during welding, a portion of the busbar 28 and a portion of the second connection 262 melt and form a molten pool, which solidifies to form the third solder mark W3. In other embodiments, a portion of the third solder mark W3 is formed by the busbar 28 and the second connection 262.

[0180] In some examples, the second connection portion 262 is located outside the first wall 251, and the busbar component 28 is welded to the second connection portion 262 to form a third solder mark W3. In other embodiments, the busbar component 28 is welded to the electrode terminal 26, and the third solder mark W3 may extend along the first direction X to the first sub-transition portion 2631.

[0181] In this embodiment of the application, by setting a third solder mark W3 to connect the bus component 28 and the second connection part 262, the connection strength between the bus component 28 and the electrode terminal 26 can be improved, and the current can be conducted to the bus component 28 through the electrode terminal 26, thereby reducing the resistance between the bus component 28 and the electrode terminal 26.

[0182] Furthermore, within the same projection plane along the first direction X, the orthographic projection of the third solder mark W3 and the orthographic projection of the first sub-transition portion 2631 are at least partially overlapped. This can shorten the conductive path between the first sub-transition portion 2631 and the third solder mark W3, reduce resistance, lower the temperature rise of the electrode terminal 26 during overcurrent, and improve the cycle performance of the battery cell 20.

[0183] In some embodiments, please refer to Figure 13, which is a schematic diagram of the connection between a battery cell 20 and a busbar component 28 disclosed in an embodiment of this application. On the same projection plane along the first direction X, the orthographic projection of the third solder mark W3 falls completely within the orthographic projection range of the first sub-transition portion 2631.

[0184] The embodiments of this application can further shorten the conductive path between the first sub-transition portion 2631 and the third solder mark W3, reduce resistance, lower the temperature rise of the electrode terminal 26 during overcurrent, improve the cycle performance of the battery cell 20, and reduce the risk of thermal runaway of the battery cell 20. When welding the second connection portion 262 and the busbar component 28, even if the second connection portion 262 is welded through, the first sub-transition portion 2631 can still prevent the molten pool from melting, reducing the risk of other components of the battery cell 20 being melted through and improving the reliability of the battery cell 20.

[0185] In some embodiments, please refer to FIG13, which is a schematic diagram of the connection between a battery cell 20 and a busbar component 28 disclosed in an embodiment of this application. Along the first direction X, the third solder mark W3 extends at least partially to the first sub-transition portion 2631.

[0186] For example, during welding, a portion of the busbar 28, a portion of the second connection 262, and a portion of the first sub-transition 2631 melt and form a molten pool, which solidifies to form a third weld mark W3.

[0187] In some embodiments, the third solder mark W3 is annular. The third solder mark W3 can be continuously disposed around the outer periphery of the second sub-transition portion 2632, which can increase the flow area and improve the consistency of the flow.

[0188] According to the battery cell 20 provided in the embodiments of this application, a portion of the current in the first sub-transition portion 2631 can be conducted to the current-conducting component through the third solder mark W3, which can further reduce resistance, reduce the temperature rise of the electrode terminal 26 during current boosting, improve the cycle performance of the battery cell 20, and reduce the risk of thermal runaway of the battery cell 20. The third solder mark W3 can also improve the stability of the connection between the first sub-transition portion 2631 and the second connection portion 262, reduce contact resistance, and improve overcurrent capability.

[0189] Secondly, embodiments of this application provide a battery device 100, including a battery cell 20 of any of the above embodiments.

[0190] In some embodiments, the battery device 100 further includes a busbar 28 connected to the electrode terminal 26 via a third solder mark W3.

[0191] In some examples, the two ends of the busbar 28 are connected to the two electrode terminals 26 of opposite polarities of the two battery cells 20, respectively, to connect the two battery cells 20 in series. Alternatively, the two ends of the busbar 28 are connected to the two electrode terminals 26 of the same polarity of the two battery cells 20, to connect the two battery cells 20 in parallel.

[0192] Thirdly, embodiments of this application also provide an electrical device, including a battery device 100 of any of the above embodiments, the battery device 100 being used to provide electrical energy.

[0193] Referring to Figures 3 and 4, this application embodiment provides a battery cell 20, which includes a housing 25, an electrode assembly 23, and two electrode terminals 26 with opposite polarities.

[0194] The housing 25 includes a housing 21 and a first wall 251. The housing 21 has an opening, and the first wall 251 is connected to the housing 21 and covers the opening. The first wall 251 is provided with two electrode lead-out holes for mounting electrode terminals 26.

[0195] The electrode assembly 23 includes a tab 231, which includes a positive tab and a negative tab.

[0196] Two electrode terminals 26 are insulatedly mounted on the first wall 251 and electrically connected to the positive electrode and the negative electrode, respectively.

[0197] The electrode terminal 26 includes a first connecting portion 261, a second connecting portion 262, a transition portion 263 connecting the two, and a sealing component 24.

[0198] The first connecting portion 261 is located on the side surface of the first wall 251 facing the electrode assembly 23 and is electrically connected to the tab 231. The second connecting portion 262 is located on the side surface of the first wall 251 facing away from the electrode assembly 23. The second connecting portion 262 may be provided with a first through hole. The transition portion 263 includes a first sub-transition portion 2631 and a second sub-transition portion 2632. The first sub-transition portion 2631 passes through the electrode lead-out hole of the first wall 251, and the second sub-transition portion 2632 passes through the first through hole of the second connecting portion 262. Along the first direction X, the first sub-transition portion 2631 and the first connecting portion 261 abut against each other, where the first direction X is opposite to the thickness of the first wall 251. At least a portion of the sealing member 24 is disposed between the first connecting portion 261 and the first wall 251.

[0199] The first connecting part 261 can be electrically connected to the electrode 231 through the adapter component. The first connecting part 261 is connected to the adapter component through the first solder mark W1, and the electrode 231 is connected to the adapter component through the second solder mark W2.

[0200] The first connecting portion 261 includes a thickened portion 2611 and a main body portion, with the thickened portion 2611 connected to the adapter member 27. Along the first direction X, the thickened portion 2611 protrudes from the main body portion 2612 on the side facing the electrode assembly 23, and is connected to the adapter member 27 via a first solder mark W1. The adapter member 27 includes a tab connection area 271 and a terminal connection area 272. Along the first direction X, the thickness of the tab connection area 271 is greater than the thickness of the terminal connection area 272. The tab connection area 271 and the terminal connection area 272 together form a groove located on the surface of the adapter member 27 facing away from the electrode assembly 23. Along the first direction X, the electronic connection area and the thickened portion 2611 are disposed opposite each other, and in the same projection plane perpendicular to the first direction X, the orthographic projection of the thickened portion 2611 completely falls into the orthographic projection of the terminal connection area 272. Along the first direction X, the dimension of the thickened portion 2611 extending beyond the main body portion 2612 is greater than the depth of the groove.

[0201] In the same projection plane perpendicular to the first direction X, the orthographic projection of the sealing component 24 and the orthographic projection of the first solder mark W1 do not overlap, and the orthographic projection of the sealing component 24 is annular and surrounds the outside of the orthographic projection of the first solder mark W1.

[0202] Along the width direction of the first wall 251, the second solder mark W2 and the terminal connection area 272 are spaced apart.

[0203] The area of ​​the smallest cross section of the first sub-transition part 2631 perpendicular to the first direction X is S1, and the area of ​​the smallest cross section of the second sub-transition part 2632 perpendicular to the first direction X is S2. S1 and S2 satisfy: 1.2≤S1 / S2≤3.

[0204] The second connection portion 262 is connected to the busbar component 28 via the third solder mark W3. In the same projection plane perpendicular to the first direction X, the orthographic projection of the third solder mark W3 falls completely within the orthographic projection range of the first sub-transition portion 2631, and along the first direction X, the third solder mark W3 extends at least partially to the first sub-transition portion 2631.

[0205] The battery cell 20 provided by the above embodiment can reduce the risk of the sealing component 24 being burned, improve the reliability of the sealing component 24, and thus improve the service life of the battery cell 20.

[0206] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. 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 battery cell, characterized in that, include; An outer casing, including a receiving cavity, the outer casing having a first wall; An electrode assembly, located within the receiving cavity, includes tabs; An electrode terminal is disposed on the first wall and is used for electrical connection with the tab. The electrode terminal includes a first connecting portion, which is at least partially disposed on the side of the first wall facing the electrode assembly. A sealing component is at least partially disposed between the first connecting portion and the first wall; The first connecting portion includes a thickened portion and a main body portion. The thickened portion protrudes from the side of the main body portion facing the electrode assembly, and the thickened portion is electrically connected to the tab via a first solder mark.

2. The battery cell according to claim 1, characterized in that, Along the length of the first wall, the size of the thickened portion is equal to the size of the main body portion.

3. The battery cell according to claim 1 or 2, characterized in that, Along the first direction, the size of the thickened portion is less than 1 mm, and the first direction is the thickness direction of the first wall.

4. The battery cell according to any one of claims 1-3, wherein the battery cell further comprises an adapter component, the adapter component connecting the tab and the thickened portion, and the adapter component being connected to the thickened portion via the first solder mark.

5. The battery cell according to claim 4, characterized in that, The adapter includes a tab connection area and a terminal connection area. The terminal connection area is connected to the electrode terminal through the first solder mark. The tab connection area is connected to the tab. Along the first direction, the thickness of the tab connection area is greater than the thickness of the terminal connection area. The tab connection area and the terminal connection area together form a groove. The groove is located on the side surface of the adapter away from the electrode assembly. The electrode terminal is at least partially accommodated in the groove.

6. The battery cell according to claim 5, characterized in that, Along the first direction, the depth of the groove is less than 1 mm.

7. The battery cell according to claim 6, characterized in that, Along the first direction, the main body and the electrode connection area are separated by a gap.

8. The battery cell according to claim 5, characterized in that, The terminal connection area is disposed opposite to the thickened portion, and in the same projection plane perpendicular to the first direction, the orthographic projection of the thickened portion falls completely into the orthographic projection of the groove.

9. The battery cell according to any one of claims 5, characterized in that, The adapter component further includes a second solder mark, which is located in the tab connection area, and the adapter component is connected to the tab through the second solder mark.

10. The battery cell according to claim 9, characterized in that, Along the width direction of the first wall, the terminal connection area at least partially overlaps with the second solder mark.

11. The battery cell according to claim 9, characterized in that, Along the first direction, the main body portion at least partially overlaps with the second solder mark.

12. The battery cell according to claim 1, characterized in that, Within the same projection plane perpendicular to the first direction, the orthographic projection of the sealing component and the orthographic projection of the first solder mark do not overlap.

13. The battery cell according to claim 12, characterized in that, Within the same projection plane perpendicular to the first direction, the orthographic projection of the sealing component is annular and located outside the orthographic projection of the first solder mark.

14. The battery cell according to claim 1, characterized in that, The electrode terminal further includes a second connecting portion and a transition portion connecting the first connecting portion and the second connecting portion. The second connecting portion is located on the side of the first wall opposite to the electrode assembly, and the transition portion at least partially penetrates the first wall.

15. The battery cell according to claim 14, characterized in that, The transition portion includes a first sub-transition portion and a second sub-transition portion. The first sub-transition portion penetrates the first wall, and the second sub-transition portion penetrates the second connecting portion. On a cross-section perpendicular to the first direction, the area of ​​the smallest cross-section of the first sub-transition portion is greater than the area of ​​the smallest cross-section of the second sub-transition portion.

16. The battery cell according to claim 15, characterized in that, The surface of the first sub-transition portion away from the first connecting portion abuts against the second connecting portion.

17. The battery cell according to claim 15 or 16, characterized in that, The area of ​​the minimum cross section of the first sub-transition part perpendicular to the first direction is S1, and the area of ​​the minimum cross section of the second sub-transition part perpendicular to the first direction is S2. S1 and S2 satisfy: 1.2≤S1 / S2≤3.

18. The battery cell according to any one of claims 15-17, characterized in that, The second sub-transition portion is connected to the second connecting portion, and along the first direction, at least a portion of the second sub-transition portion is located on the side of the second connecting portion opposite to the electrode assembly.

19. The battery cell according to claim 15, characterized in that, The second connection portion includes a third solder mark for connection with the busbar component, wherein the orthographic projection of the third solder mark at least partially overlaps with the orthographic projection of the first sub-transition portion in the same projection plane along the first direction.

20. The battery cell according to claim 19, characterized in that, Within the same projection plane along the first direction, the orthographic projection of the third solder mark falls completely within the orthographic projection range of the first sub-transition portion.

21. The battery cell according to claim 20, characterized in that, Along the first direction, the third solder mark extends at least partially to the first sub-transition portion.

22. A battery device, characterized in that, It includes multiple battery cells according to any one of claims 1-21.

23. The battery device according to claim 22, characterized in that, It also includes the busbar component, which is connected to the electrode terminal via a third solder mark.

24. An electrical appliance, characterized in that, Includes the battery device of claim 22 or 23, the battery device being used to provide electrical energy.

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