Battery cell, battery device, and electric device

Abstract

A battery cell, a battery assembly, and an electrical device are provided. The battery cell includes a casing, an electrode assembly, electrode terminals, and a plurality of first solder marks. The casing has a wall portion with lead-out holes. The electrode assembly is housed within the casing and has a main body portion and tabs, with the tabs protruding from the main body portion. The electrode terminals are disposed in the wall portion and include an integrally formed body portion and a connecting portion. The body portion passes through the lead-out holes, with one end of the body portion facing the electrode assembly connected to the connecting portion, and the other end of the body portion extending out of the lead-out holes along the direction from the electrode assembly towards the wall portion. The connecting portion is located on the side of the wall portion facing the electrode assembly. One connecting portion is connected to one tab through a plurality of first solder marks, with the plurality of first solder marks spaced apart. The connection of one connecting portion to one tab through a plurality of first solder marks results in a shorter welding trajectory and lower temperature rise when forming one first solder mark in a single welding operation, thereby improving welding quality and the reliability of the battery cell.

Description

Technical Field

[0001] This application relates to the field of batteries, and more specifically, to a battery cell, a battery device, and an electrical device. Background Technology

[0002] Batteries are widely used in the new energy field, such as in electric vehicles and new energy vehicles, which have become a new trend in the automotive industry. The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Furthermore, battery reliability also needs to be considered. However, current battery reliability is relatively poor. Utility Model Content

[0003] The purpose of this application is to provide a battery cell, a battery device, and an electrical device, which aims to improve the problem of poor battery reliability in related technologies.

[0004] In a first aspect, embodiments of this application provide a battery cell, the battery cell including a casing, an electrode assembly, electrode terminals, and a plurality of first solder marks, the casing having a wall portion, the wall portion having an outlet hole; the electrode assembly being housed within the casing, the electrode assembly having a main body portion and a tab, the tab protruding from the main body portion; the electrode terminal being disposed on the wall portion, the electrode terminal including an integrally formed body portion and a connecting portion, the body portion passing through the outlet hole, one end of the body portion facing the electrode assembly being connected to the connecting portion, the other end of the body portion extending out of the outlet hole along the direction of the electrode assembly pointing towards the wall portion, the connecting portion being located on the side of the wall portion facing the electrode assembly; one connecting portion is connected to one tab through a plurality of first solder marks, the plurality of first solder marks being spaced apart.

[0005] In the above technical solution, the electrode terminal includes an integrally formed body and a connecting part. The body and connecting part have better overall integrity, higher connection stability, and lower resistance. Furthermore, welding the connecting part and the tab is more convenient, which helps improve welding quality and reduce the resistance of the first solder mark. By connecting one connecting part to one tab through multiple first solder marks, on the one hand, the welding trajectory for forming a single first solder mark is shorter, the temperature rise is lower, and the deformation of the connecting part and the tab is smaller, thus improving welding quality, reducing the resistance of the first solder mark, reducing heat generation of the first solder mark during battery cell operation, and improving the reliability of the battery cell. On the other hand, even if the connection between some of the multiple first solder marks and the connecting part and the tab fails, the remaining first solder marks can still connect the connecting part and the tab, and overcurrent can still be achieved, which helps improve the reliability of the battery cell.

[0006] As an optional technical solution in this application embodiment, a plurality of first solder marks are arranged around the body portion of the electrode terminal.

[0007] In the above technical solution, by arranging multiple first solder marks around the body of the electrode terminal, on the one hand, current can be transmitted from all sides of the body to the body, reducing the risk of excessive current in a single area of ​​the connection leading to overheating. On the other hand, the distances from the multiple first solder marks to the body are approximately the same, which helps to make the current paths from the multiple first solder marks to the body approximately the same, and the current flowing through the multiple first solder marks approximately the same. This helps to reduce the risk of excessive current in a single first solder mark leading to overheating of that single first solder mark, and thus improves the reliability of the battery cell.

[0008] As an optional technical solution in this application embodiment, the extension trajectory lines of the plurality of first solder marks are respectively located on multiple sides of the polygon.

[0009] In the above technical solution, by making the extension trajectory lines of multiple first solder marks located on multiple sides of the polygon, the extension trajectory lines of the first solder marks do not pass through the center line of the main body, so that the current can be transmitted to the main body more evenly. This helps to reduce the risk of excessive current in a single area of ​​the first solder mark leading to excessive temperature, and helps to improve the reliability of the battery cell.

[0010] As an optional technical solution in this application embodiment, a plurality of first solder pads are spaced apart along a first direction, the first direction being perpendicular to the extension direction of the body portion of the electrode terminal.

[0011] In the above technical solution, by arranging multiple first solder marks at intervals along the first direction, it is beneficial to make the distance between two adjacent first solder marks larger, thereby reducing the thermal impact of two adjacent first solder marks and improving the reliability of the battery cell.

[0012] As an optional technical solution in this application embodiment, a plurality of first solder pads extend along a second direction, and the first direction, the second direction and the extension direction of the body portion are perpendicular to each other.

[0013] In the above technical solution, by making multiple first solder marks extend along the second direction, it is beneficial to increase the area of ​​a single first solder mark, reduce the resistance of the first solder mark, reduce the heat generated by the first solder mark when the battery cell is working, and improve the reliability of the battery cell.

[0014] As an optional technical solution in this application embodiment, in a projection plane perpendicular to the extension direction of the body portion, at least a portion of the projection of at least one of the first solder marks is located within the projection of the body portion, the projection of at least one of the first solder marks is located on one side of the projection of the body portion along the first direction, and the projection of at least one of the first solder marks is located on the other side of the projection of the body portion along the first direction.

[0015] In the above technical solution, the current can be transmitted from both sides of the main body along the first direction to the main body, or it can be transmitted directly to the main body through the first solder part, which is at least partially located within the projection of the main body. This helps to reduce the risk of excessive current in a single area of ​​the connection part, which could lead to excessive temperature, and helps to improve the reliability of the battery cell.

[0016] As an optional technical solution in this application embodiment, the electrode tab includes a plurality of sub-electrodes and a second solder mark, wherein the plurality of sub-electrodes are stacked and connected to each other through the first solder mark and the second solder mark.

[0017] In the above technical solution, during manufacturing, multiple sub-tabs are first stacked, then pre-welded to form a second solder mark, and then the tabs are welded to the connecting part to form a first solder mark. The first solder mark and the second solder mark are then connected. This improves the welding quality between the tabs and the connecting part, reduces the resistance of the first solder mark, reduces heat generation in the first solder mark during battery cell operation, and improves the reliability of the battery cell.

[0018] As an optional technical solution in this application embodiment, the battery cell includes a terminal group, the terminal group includes a plurality of electrode terminals, and the connection portions of the plurality of electrode terminals are all welded to the same tab of the electrode assembly.

[0019] In the above technical solution, each terminal group includes multiple electrode terminals with the same polarity. These multiple electrode terminals jointly output or input electrical energy to the battery cell, which helps improve the overcurrent capacity. Thus, the current passing through a single first solder joint is relatively small, which helps reduce the heat generated by the single first solder joint during battery cell operation and improves the reliability of the battery cell.

[0020] As an optional technical solution in this application embodiment, the terminal group includes a connector, the connector is located on the side of the wall portion away from the electrode assembly, and the connector connects to the body portion of a plurality of electrode terminals.

[0021] In the above technical solution, by setting a connector to connect the main body of multiple electrode terminals, the current of multiple electrode terminals is converged to the connector, thereby facilitating the output of electrical energy of the battery cell or the input of electrical energy to the battery cell through the connector, and facilitating the electrical connection of the connector with the busbar or electrical device.

[0022] As an optional technical solution in this application embodiment, the connector, the body part and the connecting part are integrally formed.

[0023] In the above technical solution, by integrally molding the connector, the body, and the connecting part, the integrity of the connector, the body, and the connecting part is better, the connection stability is higher, and the resistance is lower.

[0024] As an optional technical solution in this application embodiment, any two electrode terminals in the terminal group are not connected to each other.

[0025] In the above technical solution, the multiple electrode terminals in the terminal group are independent of each other and not connected to each other. There is no need to connect multiple electrode terminals through connectors, which helps to reduce the volume of the battery cell and increase the volumetric energy density of the battery cell.

[0026] As an optional technical solution in this application embodiment, the plurality of electrode terminals in the terminal group are disposed on the same wall of the housing.

[0027] In the above technical solution, by setting multiple electrode terminals on the same wall of the housing, on the one hand, multiple lead-out holes can be set on one wall during manufacturing, and multiple electrode terminals can be installed accordingly, making manufacturing simple and convenient. On the other hand, it is more convenient to electrically connect the electrode terminals to the busbar component. Furthermore, only space needs to be reserved on one wall in the battery device for connection with the busbar component, which helps to reduce the space occupied inside the battery device and improve the energy density of the battery device.

[0028] As an optional technical solution in this application embodiment, a plurality of electrode terminals are arranged along a second direction, which is perpendicular to the thickness direction of the wall portion.

[0029] In the above technical solution, by arranging multiple electrode terminals along the second direction, the space of the wall in the second direction is utilized as much as possible, and the size of the wall in the first direction is reduced, which is beneficial to controlling the size of the battery cell.

[0030] As an optional technical solution in this application embodiment, along the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, the electrode protrudes from one end of the main body portion facing the wall portion, and the length direction of the wall portion is parallel to the second direction; along the second direction, the size of the wall portion is L, and the size of the electrode is W, satisfying: 0.125≤W / L≤0.5, optionally, 0.165≤W / L≤0.25.

[0031] In the above technical solution, when W / L ≥ 0.125, the size of the tab along the second direction is relatively large, which is beneficial for increasing the size of each first solder joint. This improves the current carrying capacity of the first solder joint, reduces its resistance, reduces heat generation during battery cell operation, and enhances the reliability of the battery cell. Furthermore, the larger size of the tab along the second direction helps reduce heat generation, resulting in less heat transfer from the tab to the first solder joint, thus reducing the risk of first solder joint failure. When W / L ≤ 0.5, the size of the tab along the second direction is not excessively large, which helps reduce the risk of interference between tabs and between tabs and other components, further improving the reliability of the battery cell. Therefore, when 0.125 ≤ W / L ≤ 0.5, the reliability of the battery cell is relatively high.

[0032] When W / L ≥ 0.165, the tab's size along the second direction is larger, which allows for a larger size of each first solder joint. This improves the current-carrying capacity of the first solder joint, reduces its resistance, decreases heat generation during battery cell operation, and enhances the battery cell's reliability. Furthermore, a larger tab size along the second direction further reduces heat generation, resulting in less heat transfer from the tab to the first solder joint, thus reducing the risk of first solder joint failure. When W / L ≤ 0.5, the tab's size along the second direction is not excessively large, which helps reduce the risk of interference between tabs and between tabs and other components, further improving the battery cell's reliability. Therefore, when 0.125 ≤ W / L ≤ 0.5, the battery cell has high reliability.

[0033] As an optional technical solution in this application embodiment, the orthographic projection of the wall portion is rectangular along the thickness direction of the wall portion, the electrode protrudes from one end of the main body portion facing the wall portion, and the length direction of the wall portion is parallel to the second direction; the length of the first solder mark portion is A, and the size of the electrode mark is W along the second direction, satisfying: 0.1≤A / W≤0.5, optionally, 0.25≤A / W≤0.35.

[0034] In the above technical solution, when A / W ≥ 0.1, the size of the first solder mark is relatively large, which helps to improve the current carrying capacity of the first solder mark, reduce the resistance of the first solder mark, reduce the heat generated by the first solder mark when the battery cell is working, and improve the reliability of the battery cell. When A / W ≤ 0.5, the size of the first solder mark is not too large. On the one hand, the welding trajectory when forming a first solder mark in a single welding is shorter, the temperature rise is lower, and the deformation of the connection and the tab is smaller, which helps to improve the welding quality, reduce the resistance of the first solder mark, reduce the heat generated by the first solder mark when the battery cell is working, and improve the reliability of the battery cell. On the other hand, the distance between two adjacent first solder marks can be larger, which helps to reduce the thermal impact between two adjacent first solder marks.

[0035] When A / W ≥ 0.25, the size of the first solder mark is larger, which is more conducive to improving the current carrying capacity of the first solder mark, reducing its resistance, reducing heat generation during battery cell operation, and improving the reliability of the battery cell. When A / W ≤ 0.35, the size of the first solder mark is not too large. On the one hand, the welding trajectory when forming a first solder mark in a single welding operation is shorter, the temperature rise is lower, and the deformation of the connection and tab is smaller, which is conducive to improving welding quality, reducing the resistance of the first solder mark, reducing heat generation during battery cell operation, and improving the reliability of the battery cell. On the other hand, the distance between two adjacent first solder marks can be larger, which helps to reduce the thermal impact between two adjacent first solder marks.

[0036] As an optional technical solution in this application embodiment, the orthographic projection of the wall portion is rectangular along the thickness direction of the wall portion, the tab protrudes from the end of the main body portion facing the wall portion, the width direction of the wall portion is parallel to the first direction, and the length direction of the wall portion is parallel to the second direction; along the first direction, the size of the wall portion is D, and along the second direction, the size of the wall portion is L, satisfying: 5≤L / D≤25, optionally, 10≤L / D≤20.

[0037] In the above technical solution, when L / D ≥ 5, the difference between the wall dimension along the second direction and the wall dimension along the first direction is significant, resulting in a larger wall dimension along the second direction. This facilitates the arrangement of multiple electrode terminals along the second direction, allowing for a longer tab length along the second direction, which in turn facilitates the welding connection between multiple electrode terminals and tabs. This also results in a larger first solder mark dimension along the second direction, which improves the current carrying capacity of the first solder mark, reduces its resistance, decreases heat generation during battery cell operation, and enhances the reliability of the battery cell. Furthermore, the smaller wall dimension along the first direction facilitates heat dissipation from the battery cell. When L / D ≤ ​​25, the difference between the wall dimension along the second direction and the wall dimension along the first direction is not excessive, ensuring a less excessive current transmission path. This helps reduce the internal resistance of the battery cell, decreases heat generation, and further improves the reliability of the battery cell.

[0038] When L / D ≥ 10, the difference between the wall dimension along the second direction and the wall dimension along the first direction is greater, with the wall dimension along the second direction being larger. This facilitates the arrangement of multiple electrode terminals along the second direction, allowing for a longer tab length along the second direction, which in turn facilitates the welding connection between multiple electrode terminals and tabs. This also results in a larger first solder mark dimension along the second direction, which improves the current carrying capacity of the first solder mark, reduces its resistance, decreases heat generation during battery cell operation, and enhances the reliability of the battery cell. Furthermore, the smaller wall dimension along the first direction facilitates heat dissipation within the battery cell. When L / D ≤ ​​20, the difference between the wall dimension along the second direction and the wall dimension along the first direction is not too large, ensuring that the current transmission path is not excessively long. This helps reduce the internal resistance of the battery cell, decreases heat generation, and further improves the reliability of the battery cell.

[0039] As an optional technical solution in this application embodiment, 50mm≤L≤500mm, or optionally, 100mm≤L≤350mm.

[0040] In the above technical solution, when L≥50mm, the wall dimension along the second direction is relatively large, which facilitates the arrangement of multiple electrode terminals along the second direction and allows for a larger length of the tab along the second direction, thus facilitating the welding connection between multiple electrode terminals and the tab. This also results in a larger dimension of the first solder mark along the second direction, which improves the current carrying capacity of the first solder mark, reduces its resistance, reduces heat generation during battery cell operation, and enhances the reliability of the battery cell. When L≤500mm, the wall dimension along the second direction is not excessively large, preventing the current transmission path from becoming too long. This helps reduce the internal resistance of the battery cell, reduces heat generation, and further improves the reliability of the battery cell.

[0041] When L ≥ 100 mm, the wall dimension along the second direction is larger, which facilitates the arrangement of multiple electrode terminals along the second direction and allows for a longer tab length along the second direction, thus facilitating the welding connection between multiple electrode terminals and tabs. This results in a larger first solder mark dimension along the second direction, which improves the current carrying capacity of the first solder mark, reduces its resistance, reduces heat generation during battery cell operation, and improves the reliability of the battery cell. When L ≤ 350 mm, the wall dimension along the second direction is not excessively large, ensuring that the current transmission path is not too long. This helps reduce the internal resistance of the battery cell, reduces heat generation, and further improves the reliability of the battery cell.

[0042] As an optional technical solution in this application embodiment, the plurality of electrode terminals include a first electrode terminal, a second electrode terminal, and a third electrode terminal. The first electrode terminal and the second electrode terminal are arranged opposite to each other along a first direction. In a projection plane perpendicular to the first direction, the projections of the first electrode terminal and the third electrode terminal are spaced apart along a second direction. In a projection plane perpendicular to the second direction, the projection of the third electrode terminal is located between the projections of the first electrode terminal and the second electrode terminal. The first direction, the second direction, and the thickness direction of the wall are perpendicular to each other.

[0043] In the above technical solution, by arranging the first electrode terminal and the second electrode terminal opposite to each other along the first direction, and in a projection plane perpendicular to the first direction, the projections of the first electrode terminal and the third electrode terminal are spaced apart along the second direction, and in a projection plane perpendicular to the second direction, the projection of the third electrode terminal is located between the projections of the first electrode terminal and the second electrode terminal, so that the first electrode terminal, the second electrode terminal and the third electrode terminal are respectively located at the three vertices of an acute triangle. In this way, the third electrode terminal can make full use of the space of the wall in the first direction and the second direction, which is beneficial to controlling the size of the battery cell.

[0044] As an optional technical solution in this application embodiment, along the thickness direction of the wall portion, the tab protrudes from one end of the main body portion facing the wall portion; the battery cell includes multiple electrode assemblies, the multiple electrode assemblies are arranged along a first direction, the tabs of the multiple electrode assemblies have overlapping areas stacked along the thickness direction of the wall portion, multiple electrode terminals are welded to the same overlapping area, and the connection portion of each electrode terminal is connected to the overlapping area through multiple first solder marks, the first direction being perpendicular to the thickness direction of the wall portion.

[0045] In the above technical solution, during manufacturing, the tabs of multiple electrode assemblies can be stacked along the thickness direction of the wall to form an overlapping area. Then, the overlapping area is welded to multiple electrode terminals, and the connection part of each electrode terminal is welded to the overlapping area to form multiple first solder marks. This helps to simplify the welding steps and improve manufacturing efficiency.

[0046] As an optional technical solution in this application embodiment, the battery cell includes two terminal groups, and the polarities of the electrode terminals in the two terminal groups are opposite.

[0047] In the above technical solution, one of the two terminal groups is a positive terminal group and the other is a negative terminal group. That is, the battery cell includes multiple positive electrode terminals and multiple negative electrode terminals, which is beneficial to improving the overcurrent capacity. In this way, the current passing through a single first solder joint is smaller, which helps to reduce the heat generated by a single first solder joint when the battery cell is working, thereby improving the reliability of the battery cell.

[0048] As an optional technical solution in this application embodiment, the electrode terminals in the two terminal groups are disposed on the same wall of the housing.

[0049] In the above technical solution, by setting the electrode terminals of the two terminal groups on the same wall of the housing, on the one hand, multiple lead-out holes can be set on one wall during manufacturing, and multiple electrode terminals can be installed accordingly, making manufacturing simple and convenient. On the other hand, it is more convenient to electrically connect the electrode terminals to the busbar component. Furthermore, only one wall needs to be reserved in the battery device for connection with the busbar component, which helps to reduce the space occupied inside the battery device and improve the energy density of the battery device.

[0050] As an optional technical solution in this application embodiment, the electrode assembly is a wound electrode assembly.

[0051] In the above technical solution, when the electrode assembly is a wound electrode assembly, even if some of the sub-tabs break, the current of the electrode can still be output through the other sub-tabs, which helps to reduce the risk of undervoltage failure and has high reliability.

[0052] Secondly, embodiments of this application also provide a battery device, which includes the aforementioned battery cell.

[0053] Thirdly, embodiments of this application also provide an electrical device, which includes the aforementioned battery cell, and the battery cell is used to provide electrical energy to the electrical device. Attached Figure Description

[0054] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0055] Figure 1 This application provides structural schematic diagrams of vehicles for some embodiments;

[0056] Figure 2 Exploded views of battery devices provided in some embodiments of this application;

[0057] Figure 3 This is a schematic diagram of the structure of a battery cell provided in some embodiments of this application;

[0058] Figure 4 Exploded views of a single battery cell provided in some embodiments of this application;

[0059] Figure 5 Cross-sectional views of electrode terminals and tab connections provided in some embodiments of this application;

[0060] Figure 6 This is a schematic diagram showing the distribution of multiple first solder pads provided in some embodiments of this application;

[0061] Figure 7 A schematic diagram showing the distribution of multiple first solder pads provided in other embodiments of this application;

[0062] Figure 8 A cross-sectional view showing the connection of multiple sub-tabs, a first solder mark, and a second solder mark as provided in some embodiments of this application;

[0063] Figure 9 Exploded views of a battery cell provided in other embodiments of this application;

[0064] Figure 10 This is a schematic diagram of the connection between the electrode terminals and the tabs provided in other embodiments of this application;

[0065] Figure 11 Exploded views of a battery cell provided in some embodiments of this application;

[0066] Figure 12 A schematic diagram illustrating the connection between electrode terminals and tabs provided in some embodiments of this application;

[0067] Figure 13 Simplified structural schematic diagrams of electrode assemblies and wall portions provided in some embodiments of this application;

[0068] Figure 14 This is a top view schematic diagram of multiple electrode terminals and wall portions provided in some embodiments of this application.

[0069] Icons: 10-Box body; 11-First box body; 12-Second box body; 20-Battery cell; 21-Outer shell; 211-Shell; 212-End cap; 213-Wall; 2131-Lead-out hole; 23-Terminal group; 231-Electrode terminal; 2311-Connecting part; 2312-Body part; 2313-Limiting part; 2314-First electrode terminal; 2315-Second electrode terminal; 2316-Third electrode terminal; 22-Electrode assembly; 221-Main body; 222-Taper; 2221-Overlapping area; 2222-Sub-taper; 2223-Second solder mark; 24-First solder mark; 25-Connector; 26-Second insulating component; 27-First insulating component; 100-Battery device; 200-Controller; 300-Motor; 1000-Vehicle. Detailed Implementation

[0070] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0071] Unless otherwise defined, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used in the description of this application is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms "comprising" and "having," and any variations thereof, in the description, claims, and accompanying drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the description, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy.

[0072] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0073] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "attachment" 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; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0074] In this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, in this application, the character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0075] In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments. It should be understood that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative and should not constitute any limitation on this application.

[0076] In this application, "multiple" means two or more (including two).

[0077] In this embodiment of the application, the battery cell can be a secondary battery, which refers to a battery cell that can be recharged to activate the active materials and continue to be used after the battery cell has been discharged.

[0078] Battery cells include, but are not limited to, lithium-ion batteries, sodium-ion batteries, sodium-lithium-ion batteries, lithium metal batteries, sodium metal batteries, lithium-sulfur batteries, magnesium-ion batteries, nickel-metal hydride batteries, nickel-cadmium batteries, lead-acid batteries, etc.

[0079] A single battery cell typically includes an electrode assembly. The electrode assembly includes a positive electrode, a negative electrode, and a separator. During the charging and discharging process of a single battery cell, 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, reduces the risk of short circuits while allowing active ions to pass through.

[0080] In some embodiments, the positive electrode can be a positive electrode sheet, which may include a positive current collector and a positive active material disposed on at least one surface of the positive current collector.

[0081] As an example, the positive current collector has two surfaces opposite each other in its own thickness direction, and the positive active material is disposed on either or both of the two opposite surfaces of the positive current collector.

[0082] As an example, the positive electrode current collector can be a foil or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrode, carbon, or titanium, etc. Composite current collectors can include a polymer material base layer and a metal layer. Composite current collectors can be formed by forming a metal material (aluminum, aluminum alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0083] 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 in battery cells may also be used. These positive electrode active materials may be used alone or in combination of two or more. Examples of lithium phosphate may 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 iron manganese phosphate, and lithium iron manganese phosphate and carbon composites. Examples of lithium transition metal oxide may include, but are not limited to, lithium cobalt oxide (such as LiCoO2), lithium nickel oxide (such as LiNiO2), lithium manganese oxide (such as LiMnO2, LiMn2O4), lithium nickel cobalt oxide, lithium manganese cobalt oxide, lithium nickel manganese oxide, and lithium nickel cobalt manganese oxide (such as LiNi). 1 / 3 Co 1 / 3Mn 1 / 3 O2 (also known as NCM) 333 LiNi 0.5 Co 0.2 Mn 0.3 O2 (also known as NCM) 523 LiNi 0.5 Co 0.25 Mn 0.25 O2 (also known as NCM) 211 LiNi 0.6 Co 0.2 Mn 0.2 O2 (also known as NCM) 622 LiNi 0.8 Co 0.1 Mn 0.1 O2 (also known as NCM) 811 ), lithium nickel cobalt aluminum oxide (such as LiNi) 0.85 Co 0.15 Al 0.05At least one of O2 and its modified compounds.

[0084] In some embodiments, the positive electrode can be a foamed metal. The foamed metal can be foamed nickel, foamed copper, foamed aluminum, foamed alloys, etc. When foamed metal is used as the positive electrode, the surface of the foamed metal may or may not contain a positive electrode active material. As an example, lithium source material, potassium metal, or sodium metal can also be filled and / or deposited within the foamed metal, where the lithium source material is lithium metal and / or a lithium-rich material.

[0085] In some embodiments, the negative electrode can be a negative electrode sheet, and the negative electrode sheet can include a negative current collector.

[0086] As an example, the negative electrode current collector can be a foil, a foamed metal, or a composite current collector. For example, as a foil, it can be aluminum with a silver-plated surface, stainless steel with a silver-plated surface, stainless steel, copper, aluminum, nickel, carbon electrodes, carbon, or titanium, etc. The foamed metal can be nickel foam, copper foam, aluminum foam, foam alloy, etc. The composite current collector can include a polymer material base layer and a metal layer. The composite current collector can be formed by forming a metal material (copper, copper alloy, nickel, nickel alloy, titanium, titanium alloy, silver and silver alloy, etc.) on a polymer material substrate (such as a substrate of polypropylene, polyethylene terephthalate, polybutylene terephthalate, polystyrene, polyethylene, etc.).

[0087] As an example, the negative electrode sheet may include a negative current collector and a negative active material disposed on at least one surface of the negative current collector.

[0088] 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.

[0089] As an example, the negative electrode active material may be a negative electrode active material known in the art for use in battery cells. 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 in battery cells may also be used. These negative electrode active materials may be used alone or in combination of two or more.

[0090] In some embodiments, the positive current collector can be made of aluminum, and the negative current collector can be made of copper.

[0091] In some embodiments, the separator is a separator membrane. The separator membrane can be any known porous structure separator membrane with good chemical and mechanical stability.

[0092] As an example, the material of the separator may include at least one of glass fiber, nonwoven fabric, polyethylene, polypropylene, and polyvinylidene fluoride. The separator may be a single-layer film or a multi-layer composite film. When the separator is a multi-layer composite film, the materials of each layer may be the same or different. The separator may be a separate component located between the positive and negative electrodes, or it may be attached to the surfaces of the positive and negative electrodes.

[0093] In some embodiments, the separator is a solid electrolyte. The solid electrolyte is disposed between the positive and negative electrodes, serving both to transport ions and to isolate the positive and negative electrodes.

[0094] In some embodiments, the battery cell also includes an electrolyte, which acts as a conductor of ions between the positive and negative electrodes. The electrolyte can be liquid, gel-like, or solid. Liquid electrolytes include electrolyte salts and solvents.

[0095] In some embodiments, the electrolyte salt may include at least one of lithium hexafluorophosphate, lithium tetrafluoroborate, lithium perchlorate, lithium hexafluoroarsenate, lithium bis(fluorosulfonyl)imide, lithium bis(trifluoromethanesulfonyl)imide, lithium trifluoromethanesulfonate, lithium difluorophosphate, lithium difluorooxalate borate, lithium dioxalate borate, lithium difluorodioxalate phosphate, and lithium tetrafluorooxalate phosphate.

[0096] In some embodiments, the solvent may include at least one selected from ethylene carbonate, propylene carbonate, methyl ethyl carbonate, diethyl carbonate, dimethyl carbonate, dipropyl carbonate, methyl propyl carbonate, ethyl propyl carbonate, butyl carbonate, fluoroethylene carbonate, methyl formate, methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, methyl butyrate, ethyl butyrate, 1,4-butyrolactone, sulfolane, dimethyl sulfone, methyl ethyl sulfone, and diethyl sulfone. The solvent may also be an ether solvent. Ether solvents may include one or more selected from ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 1,3-dioxolane, tetrahydrofuran, methyl tetrahydrofuran, diphenyl ether, and crown ethers.

[0097] Among them, the gel electrolyte includes a polymer as the electrolyte backbone network, combined with an ionic liquid - lithium salt.

[0098] Solid electrolytes include polymer solid electrolytes, inorganic solid electrolytes, and composite solid electrolytes.

[0099] As an example, polymer solid electrolytes can be polyether (polyoxyethylene), polysiloxane, polycarbonate, polyacrylonitrile, polyvinylidene fluoride, polymethyl methacrylate, monoionic polymers, polyionic liquids-lithium salts, cellulose, etc.

[0100] As an example, inorganic solid electrolytes may include one or more of the following: oxide solid electrolytes (crystalline perovskite, sodium superconducting ion conductor, garnet, amorphous LiPON thin film), sulfide solid electrolytes (crystalline lithium superconducting ion conductor (lithium germanium phosphate sulfide, silver sulfide germanium ore), amorphous sulfides), halide solid electrolytes, nitride solid electrolytes, and hydride solid electrolytes.

[0101] As an example, composite solid electrolytes are formed by adding inorganic solid electrolyte fillers to polymer solid electrolytes.

[0102] In some embodiments, the electrode assembly is a wound structure. The positive electrode and the negative electrode are wound into a wound structure.

[0103] In some implementations, the electrode assembly is a stacked structure.

[0104] As an example, multiple positive and negative electrode plates can be set, and multiple positive and multiple negative electrode plates can be stacked alternately.

[0105] As an example, multiple positive electrode sheets can be set, and negative electrode sheets are folded to form multiple stacked folded segments, with a positive electrode sheet sandwiched between adjacent folded segments.

[0106] As an example, both the 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 separator can be continuously arranged between any adjacent positive or negative electrode plates by folding or rolling.

[0109] In some embodiments, the electrode assembly can be cylindrical, flat, or polygonal, etc.

[0110] In some implementations, the electrode assembly has tabs that allow current to be drawn from the electrode assembly. The tabs include a positive tab and a negative tab.

[0111] In some embodiments, the battery cell may include a housing. The housing is used to encapsulate components such as electrode assemblies and electrolytes. The housing may be made of steel, aluminum, plastic (such as polypropylene), composite metal (such as copper-aluminum composite), or aluminum-plastic film, etc.

[0112] As an example, a battery cell can be a cylindrical battery cell, a prismatic battery cell, a pouch battery cell, or a battery cell of other shapes. Prismatic battery cells include prismatic battery cells, blade-shaped battery cells, and multi-prismatic battery cells, such as hexagonal prismatic battery cells.

[0113] 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.

[0114] 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 multiple battery cells and fixing them together to form an independent module.

[0115] As an example, a battery module can be formed by bundling multiple battery cells together with cable ties.

[0116] In some embodiments, the battery device may be a battery pack, which may include a housing and one or more individual battery cell assemblies housed within the housing.

[0117] 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.

[0118] As an example, battery cell assemblies can also be housed in a housing by directly fixing multiple battery cells to the housing.

[0119] As an example, the enclosure may include a first enclosure body and a second enclosure body. The first enclosure body and the second enclosure body are fastened together to form a closed space inside the enclosure to house the individual battery cells. Here, "closed" refers to covering or closing, which can be either sealed or unsealed. The first enclosure body may be a top cover or a bottom plate.

[0120] As an example, the enclosure may include a top cover, a frame, and a bottom plate. The top cover and bottom plate are connected to the frame, creating an enclosed space inside the enclosure to house the individual battery cells.

[0121] As an example, the housing can be part of the vehicle's chassis structure. For instance, the housing's roof can be at least part of the vehicle's floor, or the housing's frame can be at least part of the vehicle's crossbeams and longitudinal beams.

[0122] In some embodiments, the battery device refers to an energy storage device, which includes a housing with a door on at least one side. Energy storage devices include energy storage containers, energy storage cabinets, etc.

[0123] Currently, judging from market trends, battery applications are becoming increasingly widespread. Batteries are not only used in energy storage systems such as hydropower, thermal power, wind power, and solar power plants, but also extensively in electric vehicles such as electric bicycles, electric motorcycles, and electric cars, as well as in military equipment and aerospace. With the continuous expansion of battery applications, market demand is also constantly increasing.

[0124] The development of battery technology must consider multiple design factors simultaneously, such as energy density, discharge capacity, and charge / discharge rate. Additionally, battery reliability must also be considered. However, current battery reliability is relatively poor.

[0125] In related technologies, a battery cell includes electrode terminals and electrode assemblies. The electrode assemblies include tabs, which are electrically connected to the electrode terminals. For example, the tabs can be directly soldered to the electrode terminals, with one tab and one electrode terminal connected via a solder joint. During battery cell operation, current flows from the solder joint to the electrode terminals, generating significant heat. This heat can easily lead to solder joint failure, causing the connection between the tabs and electrode terminals to break, thus preventing normal current output. Furthermore, excessive heat in the solder joint may ignite other components within the battery cell, leading to thermal runaway and resulting in poor battery cell reliability.

[0126] In view of this, embodiments of this application provide a battery cell, which includes a casing, an electrode assembly, electrode terminals, and a plurality of first solder marks. The casing has a wall portion with lead-out holes, and the electrode assembly is housed within the casing. The electrode assembly has a main body portion and a tab, with the tab protruding from the main body portion. The electrode terminals are disposed on the wall portion. Each electrode terminal includes an integrally formed body portion and a connecting portion. The body portion passes through the lead-out holes, and one end of the body portion facing the electrode assembly is connected to the connecting portion. The other end of the body portion extends out of the lead-out holes along the direction from the electrode assembly towards the wall portion, and the connecting portion is located on the side of the wall portion facing the electrode assembly. One connecting portion is connected to one tab through a plurality of first solder marks, and the plurality of first solder marks are spaced apart.

[0127] The electrode terminal comprises an integrally formed body and a connecting portion. The body and connecting portion exhibit better overall integrity, higher connection stability, and lower resistance. Furthermore, welding the connecting portion and the tab is more convenient, improving welding quality and reducing the resistance of the first solder mark. By connecting one connecting portion to one tab through multiple first solder marks, on the one hand, the welding trajectory for forming a single first solder mark is shorter, resulting in lower temperature rise and less deformation of the connecting portion and the tab. This improves welding quality, reduces the resistance of the first solder mark, decreases heat generation at the first solder mark during battery cell operation, and enhances battery cell reliability. On the other hand, even if the connection between some of the multiple first solder marks and the connecting portion and tab fails, the remaining first solder marks can still connect the connecting portion and the tab, allowing for current flow, further improving battery cell reliability.

[0128] The technical solutions described in the embodiments of this application are applicable to various electrical devices that use battery cells and battery devices, such as mobile phones, portable devices, laptops, electric vehicles, electric toys, power tools, vehicles, ships and spacecraft, etc. For example, spacecraft include airplanes, rockets, space shuttles and spacecraft.

[0129] For ease of explanation, the following embodiments will use a vehicle as an example of an electrical device.

[0130] Please refer to Figure 1 , Figure 1 This is a schematic diagram of the structure of a vehicle 1000 provided in some embodiments of this application. A battery device 100 is disposed inside the vehicle 1000, and the battery device 100 may 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.

[0131] 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, for the power needs of the vehicle 1000 during startup, navigation and driving.

[0132] 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.

[0133] Please refer to Figure 2 , Figure 2 This is an exploded view of a battery device 100 provided in some embodiments of this application. The battery device 100 may include a housing 10 and battery cells 20, the housing 10 being used to house the battery cells 20.

[0134] The housing 10 has an enclosed space inside for accommodating the battery cells 20. The housing 10 can have various structures. In some embodiments, the housing 10 may include a first housing body 11 and a second housing body 12, which are interlocked. The first housing body 11 and the second housing body 12 can have various shapes, such as cuboids or cylinders. The first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can also be a hollow structure open on one side. The open side of the second housing body 12 interlocks with the open side of the first housing body 11, thus forming a housing 10 with an enclosed space. Alternatively, the first housing body 11 can be a hollow structure open on one side, and the second housing body 12 can be a plate-like structure, with the second housing body 12 interlocked with the open side of the first housing body 11, thus forming a housing 10 with an accommodating chamber.

[0135] In the battery device 100, there can be one or more battery cells 20. If there are multiple battery cells 20, they can be connected in series, parallel, or in a mixed configuration. A mixed configuration means that multiple battery cells 20 are connected in both series and parallel. Alternatively, multiple battery cells 20 can be first connected in series, parallel, or in a mixed configuration to form a battery module, and then multiple battery modules can be connected in series, parallel, or in a mixed configuration to form a whole, which is then housed within the housing 10. Another option is that all battery cells 20 can be directly connected in series, parallel, or in a mixed configuration, and then the whole consisting of all battery cells 20 is housed within the housing 10.

[0136] In some embodiments, the battery device 100 may further include a busbar component, through which multiple battery cells 20 can be electrically connected to each other to achieve series, parallel, or mixed connection of the multiple battery cells 20. The busbar component may be a metallic conductor, such as copper, iron, aluminum, stainless steel, aluminum alloy, etc.

[0137] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 , Figure 3 This is a schematic diagram of the structure of a battery cell 20 provided in some embodiments of this application. Figure 4 An exploded view of a battery cell 20 provided in some embodiments of this application. Figure 5 A cross-sectional view showing the connection between electrode terminal 231 and tab 222 provided in some embodiments of this application. Figure 6This is a schematic diagram showing the distribution of multiple first solder marks 24 provided in some embodiments of this application. Embodiments of this application provide a battery cell 20, which includes a housing 21, an electrode assembly 22, electrode terminals 231, and multiple first solder marks 24. The housing 21 has a wall portion 213, and the wall portion 213 is provided with lead-out holes 2131. The electrode assembly 22 is housed within the housing 21, and the electrode assembly 22 has a main body portion 221 and tabs 222, with the tabs 222 protruding from the main body portion 221. Electrode terminals 231 are disposed on the wall portion 213. The electrode terminal 231 includes an integrally formed body portion 2312 and a connecting portion 2311. The body portion 2312 passes through the lead-out hole 2131. One end of the body portion 2312 facing the electrode assembly 22 is connected to the connecting portion 2311. The other end of the body portion 2312 extends out of the lead-out hole 2131 in the direction from the electrode assembly 22 to the wall portion 213. The connecting portion 2311 is located on the side of the wall portion 213 facing the electrode assembly 22. One connecting portion 2311 is connected to one tab 222 through a plurality of first solder marks 24, and the plurality of first solder marks 24 are spaced apart.

[0138] Battery cell 20 refers to the smallest unit that makes up battery device 100.

[0139] The housing 21 includes a housing 211 and an end cap 212. The housing 211 has a receiving space with an opening at one end for accommodating the electrode assembly 22. The end cap 212 is connected to the housing 211 and closes the opening.

[0140] End cap 212 refers to a component that covers the opening of housing 211 to isolate the internal environment of battery cell 20 from the external environment. The shape of end cap 212 can be adapted to the shape of housing 211 to fit it. Optionally, end cap 212 can be made of a material with a certain hardness and strength (such as aluminum alloy), so that end cap 212 is less prone to deformation under pressure and impact, enabling battery cell 20 to have higher structural strength and improved reliability. The material of end cap 212 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, and plastic.

[0141] The housing 211 is a component used to cooperate with the end cap 212 to form the internal environment of the battery cell 20. This internal environment can accommodate the electrode assembly 22, electrolyte, and other components. The housing 211 and the end cap 212 can be independent components. An opening can be provided on the housing 211, and the end cap 212 can be used to close the opening to form the internal environment of the battery cell 20. Alternatively, the end cap 212 and the housing 211 can be integrated. Specifically, the end cap 212 and the housing 211 can form a common mating surface before other components are inserted into the housing. When it is necessary to encapsulate the interior of the housing 211, the end cap 212 closes the housing 211. The housing 211 can have various shapes and sizes, such as cuboid, cylindrical, hexagonal prism, etc. Specifically, the shape of the housing 211 can be determined according to the specific shape and size of the electrode assembly 22. The material of the housing 211 can include, but is not limited to, copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0142] In some embodiments, the housing 211 may have an opening at only one end, with one end cap 212 correspondingly provided. In other embodiments, the housing 211 may have openings at both ends, with two end caps 212 correspondingly provided, the two end caps 212 respectively closing the two opposite openings of the housing 211. Figure 5 and Figure 6 In the embodiment shown, the housing 211 has an opening at only one end, and an end cap 212 is provided accordingly.

[0143] Electrode assembly 22 is the component in the battery cell 20 where electrochemical reactions occur. The housing 211 may contain one or more electrode assemblies 22. The electrode assembly 22 is mainly formed by winding or stacking positive and negative electrode sheets, and typically a separator is provided between the positive and negative electrode sheets. The portions of the positive and negative electrode sheets containing active material constitute the main body 221 of the electrode assembly 22, while the portions of the positive and negative electrode sheets without active material each constitute a tab 222. The positive and negative tabs may be located together at one end of the main body 221 or separately at both ends of the main body 221. During the charging and discharging process of the battery cell 20, the positive and negative active materials react with the electrolyte.

[0144] The wall portion 213 can be an end cap 212 of the outer casing 21, or it can be a wall of the housing 211 of the outer casing 21. For example, in... Figure 3 and Figure 4 In some embodiments, wall portion 213 is an end cap 212. In other embodiments, wall portion 213 is a bottom wall of housing 211 opposite to end cap 212. In still other embodiments, housing 211 includes a plurality of side walls, and wall portion 213 is one of the plurality of side walls.

[0145] The wall portion 213 is provided with a through hole 2131, which penetrates the wall portion 213 along its thickness direction. In other words, the through hole 2131 is a through hole provided in the wall portion 213. Please refer to... Figure 4 and 5 The thickness direction of the wall 213 can be the Z direction as shown in the figure.

[0146] Electrode terminals 231 are used for welding connections to the tabs 222 of the electrode assembly 22 to input or output electrical energy to the battery cell 20. Electrode terminals 231 are mounted on wall portions 213, and the location of the electrode terminals 231 determines which wall portion 213 of the housing 21 is the wall portion 213. For example, when the electrode terminals 231 are located on the end cap 212, the end cap 212 is the wall portion 213. When the electrode terminals 231 are located on the bottom wall of the housing 211, the bottom wall is the wall portion 213. It should be noted that there can be multiple electrode terminals 231; multiple electrode terminals 231 can be located on the same wall portion 213, or multiple electrode terminals 231 can be located on multiple different wall portions 213.

[0147] The electrode terminal 231 includes a body portion 2312 and a connecting portion 2311, which are integrally formed. For example, the body portion 2312 and the connecting portion 2311 are riveted to the wall portion 213. The body portion 2312 is the main structure of the electrode terminal 231, and a part of the body portion 2312 passes through the lead-out hole 2131. Optionally, the body portion 2312 is a columnar structure. The connecting portion 2311 is connected to the end of the body portion 2312 facing the inside of the outer casing 21. Along the thickness direction of the wall portion 213, the connecting portion 2311 is closer to the electrode assembly 22 than the wall portion 213. The connecting portion 2311 can abut against the wall portion 213 (it can abut directly or indirectly through other components) to prevent the body portion 2312 from disengaging from the lead-out hole 2131 in a direction away from the inside of the outer casing 21.

[0148] In some embodiments, the electrode terminal 231 further includes a limiting portion 2313, which is connected to one end of the body portion 2312 away from the interior of the outer casing 21. Along the thickness direction of the wall portion 213, the limiting portion 2313 is further away from the electrode assembly 22 than the wall portion 213. The limiting portion 2313 can abut against the wall portion 213 (either directly or indirectly through other components) to restrict the body portion 2312 from disengaging from the lead-out hole 2131 in a direction closer to the interior of the outer casing 21.

[0149] In some embodiments, the battery cell 20 further includes a first insulating member 27 disposed inside the wall portion 213. The first insulating member 27 can be used to isolate the electrical connection components within the housing 211 from the wall portion 213 to reduce the risk of short circuit. A portion of the first insulating member 27 is disposed between the connection portion 2311 and the wall portion 213 to insulate and isolate the connection portion 2311 and the wall portion 213. Exemplarily, the first insulating member 27 can be made of plastic, rubber, etc.

[0150] In some embodiments, the battery cell 20 further includes a second insulating member 26. A portion of the second insulating member 26 is disposed between the limiting portion 2313 and the wall portion 213 to insulate and isolate the limiting portion 2313 and the wall portion 213. Another portion of the second insulating member 26 is disposed between the body portion 2312 and the hole wall surface of the lead-out hole 2131 to insulate and isolate the body portion 2312 and the wall portion 213. Exemplarily, the second insulating member 26 may be made of plastic, rubber, etc.

[0151] The first solder mark 24 is a solder mark area formed for welding the connection portion 2311 and the tab 222. A portion of the first solder mark 24 extends into the connection portion 2311, and another portion of the first solder mark 24 extends into the tab 222. It should be noted that "another portion of the first solder mark 24" refers to a portion different from the portion of the first solder mark 24 that extends into the connection portion 2311. The first solder mark 24 may include only the portion extending into the connection portion 2311 and the portion extending into the tab 222, or it may include the portion extending into the connection portion 2311, the portion extending into the tab 222, and other portions.

[0152] The number of first solder marks 24 can be two, three, four or more. A connecting part 2311 is connected to a tab 222 through multiple first solder marks 24, that is, a connecting part 2311 and a tab 222 are welded together to form multiple first solder marks 24, and the multiple first solder marks 24 are spaced apart.

[0153] The electrode terminal 231 includes an integrally formed body portion 2312 and a connecting portion 2311. The body portion 2312 and the connecting portion 2311 have better overall integrity, higher connection stability, and lower resistance. Furthermore, welding the connecting portion 2311 and the tab 222 is easier, which helps improve welding quality and reduce the resistance of the first solder mark 24. By connecting one connecting portion 2311 to one tab 222 through multiple first solder marks 24, the welding trajectory for forming one first solder mark 24 in a single welding operation is shorter, the temperature rise is lower, and the deformation of the connecting portion 2311 and the tab 222 is smaller. This helps improve welding quality, reduces the resistance of the first solder mark 24, reduces heat generation of the first solder mark 24 during battery cell 20 operation, and improves the reliability of the battery cell 20. On the other hand, even if some of the first solder marks 24 fail to connect with the connecting part 2311 and the tab 222, the remaining first solder marks 24 can still connect with the connecting part 2311 and the tab 222, and can still achieve overcurrent, which is beneficial to improving the reliability of the battery cell 20.

[0154] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, a plurality of first solder marks 24 are provided around the body portion 2312 of the electrode terminal 231.

[0155] In a projection plane perpendicular to the extending direction of the body portion 2312, the projections of a plurality of first solder marks 24 surround the projection of the body portion 2312. Please refer to Figure 5 The extension direction of the body portion 2312 is parallel to the thickness direction of the wall portion 213, and the extension direction of the body portion 2312 can also be represented by the Z direction.

[0156] In some embodiments, a plurality of first solder pads 24 may be arranged in a circumferential array, and each first solder pad 24 may extend along an arc trajectory, with the center line of the body portion 2312 passing through the center of the circle corresponding to the circumference.

[0157] When there are three first solder marks 24, the three first solder marks 24 can be respectively set on the three sides of the equilateral triangle, and the center line of the main body 2312 passes through the midpoint of the equilateral triangle.

[0158] When there are four first solder marks 24, the four first solder marks 24 can be respectively set on the four sides of the square, and the center line of the main body 2312 passes through the intersection of the diagonals of the square.

[0159] By arranging multiple first solder marks 24 around the body portion 2312 of the electrode terminal 231, on the one hand, current can be transmitted from all sides of the body portion 2312 to the body portion 2312, reducing the risk of excessive current in a single area of ​​the connection portion 2311 leading to overheating. On the other hand, the distances from the multiple first solder marks 24 to the body portion 2312 are approximately the same, which helps to make the current paths from the multiple first solder marks 24 to the body portion 2312 approximately the same, and the current flowing through the multiple first solder marks 24 is approximately the same. This helps to reduce the risk of excessive current in a single first solder mark 24 leading to overheating of that single first solder mark 24, and helps to improve the reliability of the battery cell 20.

[0160] Please refer to Figure 3 , Figure 4 , Figure 5 and Figure 6 In some embodiments, the extended trajectory lines of the plurality of first solder marks 24 are respectively located on multiple sides of the polygon.

[0161] The extended trajectory lines of multiple first solder marks 24 can be located on multiple sides of a triangle, quadrilateral, pentagon or hexagon, respectively.

[0162] Optionally, the extension trajectory lines of the plurality of first solder marks 24 may be located on multiple sides of a regular polygon. For example, the extension trajectory lines of the plurality of first solder marks 24 may be located on multiple sides of an equilateral triangle, a square, a regular pentagon, or a regular hexagon.

[0163] The first solder mark 24 can extend along a straight line. When there are three first solder marks 24, the three first solder marks 24 can be respectively set on the three sides of an equilateral triangle, and the center line of the body part 2312 passes through the midpoint of the equilateral triangle. When there are four first solder marks 24, the four first solder marks 24 can be respectively set on the four sides of a square, and the center line of the body part 2312 passes through the intersection of the diagonals of the square.

[0164] By placing the extension trajectory lines of the multiple first solder marks 24 on multiple sides of the polygon, the extension trajectory lines of the first solder marks 24 do not pass through the center line of the body part 2312, so that the current can be transmitted to the body part 2312 more evenly. This helps to reduce the risk of excessive current in a single area of ​​the first solder mark 24 leading to excessive temperature, and helps to improve the reliability of the battery cell 20.

[0165] Please refer to Figure 7 , Figure 7 This is a schematic diagram showing the distribution of a plurality of first solder pads 24 provided for other embodiments of this application. In some embodiments, the plurality of first solder pads 24 are spaced apart along a first direction, which is perpendicular to the extending direction of the body portion 2312 of the electrode terminal 231.

[0166] Please refer to Figure 7 The first direction can be the X direction shown in the figure. In this case, the first direction is the width direction of the wall portion 213.

[0167] Multiple first solder marks 24 are spaced apart along a first direction. Along the first direction, the distance between any two adjacent first solder marks 24 may be equal or unequal.

[0168] Optionally, a plurality of first solder marks 24 are arranged at equal intervals along a first direction.

[0169] By arranging multiple first solder marks 24 at intervals along a first direction, it is beneficial to increase the distance between two adjacent first solder marks 24, thereby reducing the thermal impact of two adjacent first solder marks 24 and improving the reliability of the battery cell 20.

[0170] Please refer to Figure 7 In some embodiments, multiple first solder pads 24 extend along a second direction, and the first direction, the second direction, and the extension direction of the body portion 2312 are perpendicular to each other.

[0171] Please refer to Figure 7 The second direction is the Y direction shown in the figure. At this time, the second direction is parallel to the length direction of the wall 213.

[0172] The first solder mark 24 extends along a straight trajectory, and the extension direction of the first solder mark 24 is parallel to the second direction.

[0173] By extending multiple first solder marks 24 along the second direction, it is beneficial to increase the area of ​​a single first solder mark 24, reduce the resistance of the first solder mark 24, reduce the heat generated by the first solder mark 24 when the battery cell 20 is working, and improve the reliability of the battery cell 20.

[0174] Please refer to Figure 7 In some embodiments, at least a portion of the projection of at least one first solder mark 24 is located within the projection of the body portion 2312 in a projection plane perpendicular to the extending direction of the body portion 2312. The projection of at least one first solder mark 24 is located on one side of the projection of the body portion 2312 along the first direction, and the projection of at least one first solder mark 24 is located on the other side of the projection of the body portion 2312 along the first direction.

[0175] At least a portion of the projection of at least one first solder mark 24 in a projection plane perpendicular to the extension direction of the body portion 2312 is located within the projection of the body portion 2312 in a projection plane perpendicular to the extension direction of the body portion 2312. When the wall portion 213 is an end cap 212, at least a portion of the first solder mark 24 is located directly below the body portion 2312.

[0176] The projection of at least one first solder mark 24 in a projection plane perpendicular to the extension direction of the body portion 2312 is located on one side of the projection of the body portion 2312 in a projection plane perpendicular to the extension direction of the body portion 2312 along the first direction, and the projection of at least one first solder mark 24 in a projection plane perpendicular to the extension direction of the body portion 2312 is located on the other side of the projection of the body portion 2312 in a projection plane perpendicular to the extension direction of the body portion 2312 along the first direction.

[0177] Please refer to Figure 7 In the embodiment shown in the figure, there are three first solder marks 24, which are spaced apart along a first direction. In a projection plane perpendicular to the extension direction of the body portion 2312, at least a portion of the projection of the middle first solder mark 24 along the first direction is located within the projection of the body portion 2312, and the projections of the other two first solder marks 24 are located on both sides of the projection of the body portion 2312 along the first direction.

[0178] Current can be transmitted from both sides of the body portion 2312 along the first direction to the body portion 2312, or it can be transmitted directly to the body portion 2312 through the first solder mark portion 24 whose projection is at least partially located within the projection of the body portion 2312. This helps to reduce the risk of excessive current in a single area on the connection portion 2311 leading to excessive temperature, and helps to improve the reliability of the battery cell 20.

[0179] Please refer to Figure 8 , Figure 8 This is a cross-sectional view showing the connection of multiple sub-tabs 2222, a first solder mark 24, and a second solder mark 2223 according to some embodiments of this application. In some embodiments, the tab 222 includes multiple sub-tabs 2222 and a second solder mark 2223, and the multiple sub-tabs 2222 are stacked and connected to each other through the first solder mark 24 and the second solder mark 2223.

[0180] During manufacturing, multiple sub-tabs 2222 are first stacked, then the multiple sub-tabs 2222 are pre-welded to form a second solder mark 2223, and then the tabs 222 are welded to the connecting part 2311 to form a first solder mark 24, and the first solder mark 24 and the second solder mark 2223 are connected.

[0181] Optionally, multiple sub-tabs 2222 are ultrasonically welded to form a second weld mark 2223.

[0182] By pre-welding multiple sub-tabs 2222, the welding quality between the tabs 222 and the connecting part 2311 can be improved, the resistance of the first solder mark 24 can be reduced, the heat generated by the first solder mark 24 when the battery cell 20 is working can be reduced, and the reliability of the battery cell 20 can be improved.

[0183] Please refer to Figure 9 and Figure 10 , Figure 9 Exploded view of a battery cell 20 provided for other embodiments of this application. Figure 10 This is a schematic diagram of the connection between electrode terminals 231 and tabs 222 provided in other embodiments of this application. In some embodiments, the battery cell 20 includes a terminal group 23, which includes a plurality of electrode terminals 231, and the connection portions 2311 of the plurality of electrode terminals 231 are all welded to the same tab 222 of the electrode assembly 22.

[0184] Terminal group 23 may include two electrode terminals 231, three electrode terminals 231, four electrode terminals 231, or more electrode terminals 231.

[0185] The connecting portions 2311 of the multiple electrode terminals 231 are all welded to the same tab 222 of the electrode assembly 22, that is, the multiple electrode terminals 231 have the same polarity. The multiple electrode terminals 231 can be independent of each other or connected to each other.

[0186] Each terminal group 23 includes multiple electrode terminals 231 with the same polarity. The multiple electrode terminals 231 jointly output or input electrical energy to the battery cell 20, which helps to improve the overcurrent capacity. In this way, the current passing through a single first solder joint 24 is smaller, which helps to reduce the heat generated by a single first solder joint 24 when the battery cell 20 is working, and improves the reliability of the battery cell 20.

[0187] Please refer to Figure 9 and Figure 10 In some embodiments, the terminal group 23 includes a connector 25 located on the side of the wall portion 213 opposite to the electrode assembly 22, and the connector 25 connects to the body portion 2312 of a plurality of electrode terminals 231.

[0188] The connector 25 is a component that connects the body portion 2312 of the plurality of electrode terminals 231. The connector 25 is disposed on the side of the wall portion 213 opposite to the electrode assembly 22. Along the thickness direction of the wall portion 213, the connector 25 is further away from the electrode assembly 22 than the wall portion 213. The connector 25 can abut against the wall portion 213 (either directly or indirectly through other components) to prevent the body portion 2312 from disengaging from the lead-out hole 2131 in a direction closer to the interior of the housing 21.

[0189] By connecting the main body 2312 of multiple electrode terminals 231 with the connector 25, the current of the multiple electrode terminals 231 is converged to the connector 25, thereby facilitating the output of electrical energy of the battery cell 20 or the input of electrical energy to the battery cell 20 through the connector 25, and facilitating the electrical connection of the connector 25 with the busbar or electrical device.

[0190] In some embodiments, the connector 25, the body portion 2312, and the connecting portion 2311 are integrally formed.

[0191] Optionally, the connector 25, the body portion 2312, and the connecting portion 2311 are riveted structures that are riveted to the wall portion 213.

[0192] By integrally molding the connector 25, the body 2312, and the connecting part 2311, the overall integrity of the connector 25, the body 2312, and the connecting part 2311 is improved, the connection stability is higher, and the resistance is lower.

[0193] Please refer to Figure 11 and Figure 12 , Figure 11 An exploded view of a battery cell 20 provided for some embodiments of this application. Figure 12 This is a schematic diagram illustrating the connection between electrode terminals 231 and tabs 222 according to some embodiments of this application. In some embodiments, any two electrode terminals 231 in the terminal group 23 are not connected to each other.

[0194] The multiple electrode terminals 231 in the terminal group 23 are independent of each other and are not connected to each other. There is no need to connect the multiple electrode terminals 231 through the connector 25, which helps to reduce the volume of the battery cell 20 and increase the volumetric energy density of the battery cell 20.

[0195] Please refer to Figure 11 and Figure 12 In some embodiments, multiple electrode terminals 231 in the terminal group 23 are disposed on the same wall portion 213 of the housing 21.

[0196] All electrode terminals 231 in terminal group 23 are disposed on the same wall portion 213 of housing 21. Please refer to... Figure 11 and Figure 12 In the embodiment shown in the figure, the wall portion 213 is an end cap 212. All electrode terminals 231 in the terminal group 23 are disposed on the end cap 212.

[0197] By arranging multiple electrode terminals 231 on the same wall portion 213 of the housing 21, on the one hand, during manufacturing, multiple lead-out holes 2131 can be provided on one wall portion 213, and multiple electrode terminals 231 can be installed accordingly, making manufacturing simple and convenient. On the other hand, it is more convenient to electrically connect the electrode terminals 231 to the busbar component. Furthermore, in the battery device 100, only one wall portion 213 needs to be reserved for connection with the busbar component, which helps to reduce the space occupied inside the battery device 100 and improve the energy density of the battery device 100.

[0198] Please refer to Figure 11 and Figure 12 In some embodiments, a plurality of electrode terminals 231 are arranged along a second direction, which is perpendicular to the thickness direction of the wall portion 213.

[0199] Please refer to Figure 11 and Figure 12 In the embodiment shown in the figure, the second direction is the length direction of the wall portion 213. Along the second direction, a plurality of electrode terminals 231 are spaced apart.

[0200] By arranging multiple electrode terminals 231 along the second direction, the space of the wall portion 213 along the second direction is utilized as much as possible, and the size of the wall portion 213 in the first direction is reduced, which is beneficial to controlling the size of the battery cell 20.

[0201] Please refer to Figure 11 , Figure 12 and Figure 13 , Figure 13 This is a simplified structural diagram of the electrode assembly 22 and the wall portion 213 provided in some embodiments of this application. In some embodiments, the orthographic projection of the wall portion 213 along its thickness direction is rectangular, and the tab 222 protrudes from the end of the main body portion 221 facing the wall portion 213. The length direction of the wall portion 213 is parallel to a second direction. Along the second direction, the dimension of the wall portion 213 is L, and the dimension of the tab 222 is W, satisfying: 0.125 ≤ W / L ≤ 0.5.

[0202] L represents the dimension of the wall portion 213 along the second direction, that is, the length of the wall portion 213.

[0203] W represents the dimension of the tab 222 along the second direction. During measurement, the dimension of the area of ​​the tab 222 used for welding to the connector 2311 along the second direction can be measured as W.

[0204] W / L represents the ratio of the dimension of the tab 222 along the second direction to the dimension of the wall portion 213 along the second direction.

[0205] W / L can be 0.125, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0206] When W / L ≥ 0.125, the tab 222 has a larger dimension along the second direction, which facilitates a larger dimension for each first solder mark 24. This improves the current carrying capacity of the first solder mark 24, reduces its resistance, decreases heat generation during battery cell 20 operation, and enhances the reliability of the battery cell 20. Furthermore, the larger dimension of the tab 222 along the second direction helps reduce heat generation, resulting in less heat transferred from the tab 222 to the first solder mark 24, thus reducing the risk of failure. When W / L ≤ 0.5, the tab 222's dimension along the second direction is not excessively large, reducing the risk of interference between tabs 222 and between tabs 222 and other components, further improving the reliability of the battery cell 20. Therefore, when 0.125 ≤ W / L ≤ 0.5, the battery cell 20 has high reliability.

[0207] Optionally, 0.165 ≤ W / L ≤ 0.25.

[0208] W / L can be 0.165, 0.175, 0.185, 0.195, 0.2, 0.205, 0.215, 0.225, 0.235, 0.245, 0.25, etc.

[0209] When W / L ≥ 0.165, the tab 222 has a larger dimension along the second direction, which allows for a larger dimension of each first solder mark 24. This improves the current carrying capacity of the first solder mark 24, reduces its resistance, and decreases the heat generated by the first solder mark 24 during battery cell 20 operation, thus improving the reliability of the battery cell 20. Furthermore, a larger dimension of the tab 222 along the second direction further reduces heat generation, resulting in less heat transferred from the tab 222 to the first solder mark 24, reducing the risk of failure. When W / L ≤ 0.5, the dimension of the tab 222 along the second direction is not excessively large, which helps reduce the risk of interference between tabs 222 and between tabs 222 and other components, further improving the reliability of the battery cell 20. Therefore, when 0.125 ≤ W / L ≤ 0.5, the reliability of the battery cell 20 is relatively high.

[0210] Please refer to this again. Figure 6 and Figure 7 In some embodiments, the orthographic projection of the wall portion 213 along its thickness direction is rectangular, and the tab 222 protrudes from the end of the main body portion 221 facing the wall portion 213. The length direction of the wall portion 213 is parallel to the second direction. The length of the first solder mark portion 24 is A, and the dimension of the tab 222 along the second direction is W, satisfying: 0.1≤A / W≤0.5.

[0211] A represents the length of the first solder mark 24. During measurement, the measurement is performed along the extending direction of the first solder mark 24. For example, if the first solder mark 24 extends along a straight line, then the length of the first solder mark 24 is the straight-line distance between its two ends.

[0212] A / W represents the ratio of the length of the first solder mark 24 to the dimension of the tab 222 along the second direction.

[0213] A / W can be 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, etc.

[0214] When A / W ≥ 0.1, the size of the first solder mark 24 is relatively large, which helps to improve the current carrying capacity of the first solder mark 24, reduce the resistance of the first solder mark 24, reduce the heat generated by the first solder mark 24 when the battery cell 20 is working, and improve the reliability of the battery cell 20. When A / W ≤ 0.5, the size of the first solder mark 24 is not too large. On the one hand, the welding trajectory when forming a first solder mark 24 in a single welding is shorter, the temperature rise is lower, and the deformation of the connecting part 2311 and the tab 222 is smaller, which helps to improve the welding quality, reduce the resistance of the first solder mark 24, reduce the heat generated by the first solder mark 24 when the battery cell 20 is working, and improve the reliability of the battery cell 20. On the other hand, the distance between two adjacent first solder marks 24 can be larger, which helps to reduce the thermal impact between two adjacent first solder marks 24.

[0215] Optionally, 0.25 ≤ A / W ≤ 0.35.

[0216] A / W can be 0.25, 0.26, 0.27, 0.28, 0.29, 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, etc.

[0217] When A / W ≥ 0.25, the size of the first solder mark 24 is larger, which is more conducive to improving the current carrying capacity of the first solder mark 24, reducing the resistance of the first solder mark 24, reducing the heat generated by the first solder mark 24 when the battery cell 20 is working, and improving the reliability of the battery cell 20. When A / W ≤ 0.35, the size of the first solder mark 24 is not too large. On the one hand, the welding trajectory when forming a first solder mark 24 in a single welding is shorter, the temperature rise is lower, and the deformation of the connecting part 2311 and the tab 222 is smaller, which is conducive to improving the welding quality, reducing the resistance of the first solder mark 24, reducing the heat generated by the first solder mark 24 when the battery cell 20 is working, and improving the reliability of the battery cell 20. On the other hand, the distance between two adjacent first solder marks 24 can be larger, which is conducive to reducing the thermal impact between two adjacent first solder marks 24.

[0218] Please refer to this again. Figure 13 In some embodiments, the orthographic projection of the wall portion 213 along its thickness direction is rectangular, and the tab 222 protrudes from the end of the main body portion 221 facing the wall portion 213. The width direction of the wall portion 213 is parallel to a first direction, and the length direction of the wall portion 213 is parallel to a second direction. The dimension of the wall portion 213 is D along the first direction and L along the second direction, satisfying: 5 ≤ L / D ≤ ​​25.

[0219] D represents the dimension of the wall portion 213 along the first direction, that is, the width of the wall portion 213.

[0220] L / D represents the ratio of the dimension of the wall portion 213 along the second direction to the dimension of the wall portion 213 along the first direction, that is, the ratio of the length of the wall portion 213 to the width of the wall portion 213.

[0221] L / D can be 5, 8, 10, 12, 15, 18, 20, 22, 25, etc.

[0222] When L / D ≥ 5, the dimension of the wall portion 213 along the second direction differs significantly from its dimension along the first direction. The larger dimension of the wall portion 213 along the second direction facilitates the arrangement of multiple electrode terminals 231 along the second direction, and allows for a larger length of the tab 222 along the second direction, thus facilitating the welding connection between the multiple electrode terminals 231 and the tab 222. This also results in a larger dimension of the first solder mark portion 24 along the second direction, which improves its current-carrying capacity, reduces its resistance, decreases heat generation during battery cell 20 operation, and enhances the reliability of the battery cell 20. Furthermore, the smaller dimension of the wall portion 213 along the first direction facilitates heat dissipation from the battery cell 20. When L / D≤25, the difference between the dimension of the wall portion 213 along the second direction and the dimension of the wall portion 213 along the first direction is not too large, and the dimension of the wall portion 213 along the second direction is not too large, so that the current transmission path is not too large, which is beneficial to reduce the internal resistance of the battery cell 20, reduce the heat generation of the battery cell 20, and improve the reliability of the battery cell 20.

[0223] Optionally, 10 ≤ L / D ≤ ​​20.

[0224] L / D can be 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, etc.

[0225] When L / D ≥ 10, the difference between the dimension of the wall portion 213 along the second direction and the dimension of the wall portion 213 along the first direction is greater, resulting in a larger dimension of the wall portion 213 along the second direction. This facilitates the arrangement of multiple electrode terminals 231 along the second direction and allows for a longer length of the tab 222 along the second direction, thus facilitating the welding connection between the multiple electrode terminals 231 and the tab 222. This also results in a larger dimension of the first solder mark portion 24 along the second direction, which improves the current carrying capacity of the first solder mark portion 24, reduces its resistance, decreases the heat generated by the first solder mark portion 24 during battery cell 20 operation, and improves the reliability of the battery cell 20. Furthermore, the smaller dimension of the wall portion 213 along the first direction facilitates heat dissipation from the battery cell 20. When L / D≤20, the difference between the dimension of the wall portion 213 along the second direction and the dimension of the wall portion 213 along the first direction is not too large, and the dimension of the wall portion 213 along the second direction is not too large, so that the current transmission path is not too large, which is beneficial to reducing the internal resistance of the battery cell 20, reducing the heat generation of the battery cell 20, and improving the reliability of the battery cell 20.

[0226] In some embodiments, 50mm ≤ L ≤ 500mm.

[0227] L can be 50mm, 100mm, 150mm, 200mm, 250mm, 300mm, 350mm, 400mm, 450mm, 500mm, etc.

[0228] When L ≥ 50 mm, the wall portion 213 has a larger dimension along the second direction, which facilitates the arrangement of multiple electrode terminals 231 along the second direction and allows for a larger length of the tab 222 along the second direction, thus facilitating the welding connection between the multiple electrode terminals 231 and the tab 222. This also results in a larger dimension of the first solder mark portion 24 along the second direction, which improves the current carrying capacity of the first solder mark portion 24, reduces its resistance, reduces heat generation during battery cell 20 operation, and improves the reliability of the battery cell 20. When L ≤ 500 mm, the wall portion 213's dimension along the second direction is not excessively large, ensuring the current transmission path is not too long. This helps reduce the internal resistance of the battery cell 20, reduces heat generation, and improves the reliability of the battery cell 20.

[0229] Optionally, 100mm≤L≤350mm.

[0230] L can be 100mm, 120mm, 150mm, 180mm, 200mm, 220mm, 250mm, 280mm, 300mm, 320mm, 350mm, etc.

[0231] When L ≥ 100 mm, the wall portion 213 has a larger dimension along the second direction, which facilitates the arrangement of multiple electrode terminals 231 along the second direction and allows for a longer length of the tab 222 along the second direction, thus facilitating the welding connection between the multiple electrode terminals 231 and the tab 222. This also results in a larger dimension of the first solder mark portion 24 along the second direction, which helps improve the current carrying capacity of the first solder mark portion 24, reduce its resistance, decrease the heat generated by the first solder mark portion 24 during battery cell 20 operation, and improve the reliability of the battery cell 20. When L ≤ 350 mm, the dimension of the wall portion 213 along the second direction is not too large, ensuring that the current transmission path is not too long. This helps reduce the internal resistance of the battery cell 20, decrease the heat generated by the battery cell 20, and improve the reliability of the battery cell 20.

[0232] Please refer to Figure 14 , Figure 14 This is a top view schematic diagram of a plurality of electrode terminals 231 and a wall portion 213 provided in some embodiments of this application. In some embodiments, the plurality of electrode terminals 231 includes a first electrode terminal 2314, a second electrode terminal 2315, and a third electrode terminal 2316, with the first electrode terminal 2314 and the second electrode terminal 2315 disposed opposite to each other along a first direction. In a projection plane perpendicular to the first direction, the projections of the first electrode terminal 2314 and the third electrode terminal 2316 are spaced apart along a second direction. In a projection plane perpendicular to the second direction, the projection of the third electrode terminal 2316 is located between the projections of the first electrode terminal 2314 and the second electrode terminal 2315. The first direction, the second direction, and the thickness direction of the wall portion 213 are all perpendicular to each other.

[0233] Along the first direction, the first electrode terminal 2314 and the second electrode terminal 2315 are spaced apart.

[0234] In a projection plane perpendicular to the first direction, the projections of the first electrode terminal 2314 and the second electrode terminal 2315 overlap, the projections of the first electrode terminal 2314 and the third electrode terminal 2316 are spaced apart along the second direction, and the projections of the second electrode terminal 2315 and the third electrode terminal 2316 are spaced apart along the second direction.

[0235] In the projection plane perpendicular to the second direction, the projections of the first electrode terminal 2314 and the second electrode terminal 2315 are located on both sides of the projection of the third electrode terminal 2316.

[0236] The center lines of the first electrode terminal 2314, the second electrode terminal 2315, and the third electrode terminal 2316 pass through the three vertices of an acute triangle, respectively.

[0237] Optionally, the center line of the first electrode terminal 2314, the center line of the second electrode terminal 2315, and the center line of the third electrode terminal 2316 pass through the three vertices of an equilateral triangle.

[0238] By arranging the first electrode terminal 2314 and the second electrode terminal 2315 opposite each other along the first direction, and in a projection plane perpendicular to the first direction, the projections of the first electrode terminal 2314 and the third electrode terminal 2316 are spaced apart along the second direction. In a projection plane perpendicular to the second direction, the projection of the third electrode terminal 2316 is located between the projections of the first electrode terminal 2314 and the second electrode terminal 2315, such that the first electrode terminal 2314, the second electrode terminal 2315 and the third electrode terminal 2316 are respectively located at the three vertices of an acute triangle. In this way, the third electrode terminal 2316 can make full use of the space of the wall portion 213 in the first and second directions, which is beneficial to controlling the size of the battery cell 20.

[0239] Please refer to this again. Figure 9 and Figure 11 In some embodiments, along the thickness direction of the wall portion 213, the tab 222 protrudes from the end of the main body portion 221 facing the wall portion 213. The battery cell 20 includes multiple electrode assemblies 22, which are arranged along a first direction. The tabs 222 of the multiple electrode assemblies 22 have overlapping regions 2221 stacked along the thickness direction of the wall portion 213. Multiple electrode terminals 231 are welded to the same overlapping region 2221, and the connection portion 2311 of each electrode terminal 231 is connected to the overlapping region 2221 through multiple first solder marks 24. The first direction is perpendicular to the thickness direction of the wall portion 213.

[0240] The battery cell 20 may include two electrode assemblies 22, three electrode assemblies 22, four electrode assemblies 22 or more electrode assemblies 22, and the multiple electrode assemblies 22 are arranged along a first direction.

[0241] Multiple electrode assemblies 22 have their tabs 222 stacked along the thickness direction of the wall portion 213 to form an overlap area 2221. All electrode terminals 231 in the terminal group 23 are soldered to the same overlap area 2221. The connecting portion 2311 of each electrode terminal 231 is soldered to the overlap area 2221 to form multiple first solder marks 24. A portion of the first solder mark 24 extends into the connecting portion 2311, and another portion of the first solder mark 24 extends into the overlap area 2221 to connect the tabs 222 of the multiple electrode assemblies 22.

[0242] During manufacturing, the tabs 222 of multiple electrode assemblies 22 can be stacked along the thickness direction of the wall portion 213 to form an overlapping area 2221. Then, the overlapping area 2221 is welded to multiple electrode terminals 231, and the connecting portion 2311 of each electrode terminal 231 is welded to the overlapping area 2221 to form multiple first solder marks 24, which helps to simplify the welding steps and improve manufacturing efficiency.

[0243] Please refer to Figure 9 and Figure 11 In some embodiments, the battery cell 20 includes two terminal groups 23, and the electrode terminals 231 in the two terminal groups 23 have opposite polarities.

[0244] The battery cell 20 includes two terminal groups 23. One of the terminal groups 23 is the positive terminal group, and multiple electrode terminals 231 in the positive terminal group are connected to a positive tab of the electrode assembly 22. The other of the two terminal groups 23 is the negative terminal group, and multiple electrode terminals 231 in the negative terminal group are connected to a negative tab of the electrode assembly 22.

[0245] One of the two terminal groups 23 is a positive terminal group, and the other is a negative terminal group. That is, the battery cell 20 includes multiple positive electrode terminals and multiple negative electrode terminals, which helps to improve the overcurrent capacity. In this way, the current passing through a single first solder joint 24 is smaller, which helps to reduce the heat generated by a single first solder joint 24 when the battery cell 20 is working, and improves the reliability of the battery cell 20.

[0246] Please refer to Figure 9 and Figure 11 In some embodiments, the electrode terminals 231 of the two terminal groups 23 are disposed on the same wall portion 213 of the housing 21.

[0247] All electrode terminals 231 in the two terminal groups 23 are disposed on the same wall portion 213 of the housing 21. Please refer to... Figure 9 and Figure 11 In the embodiment shown in the figure, the wall portion 213 is an end cap 212. All electrode terminals 231 in the two terminal groups 23 are disposed on the end cap 212.

[0248] By placing the electrode terminals 231 of the two terminal groups 23 on the same wall portion 213 of the housing 21, on the one hand, during manufacturing, multiple lead-out holes 2131 can be provided on one wall portion 213, and multiple electrode terminals 231 can be installed accordingly, making manufacturing simple and convenient. On the other hand, it is more convenient to electrically connect the electrode terminals 231 to the busbar component. Furthermore, in the battery device 100, only one wall portion 213 needs to be reserved for connection with the busbar component, which helps to reduce the space occupied inside the battery device 100 and improve the energy density of the battery device 100.

[0249] In some embodiments, electrode assembly 22 is a wound electrode assembly.

[0250] When the electrode assembly 22 is a wound electrode assembly, even if some of the sub-tabs 2222 break, the current of the electrode can still be output through the other sub-tabs 2222, which helps to reduce the risk of undervoltage failure and has high reliability.

[0251] This application embodiment also provides a battery device 100, which includes the aforementioned battery cell 20.

[0252] This application embodiment also provides an electrical device, which includes the aforementioned battery cell 20, and the battery cell 20 is used to provide electrical energy to the electrical device.

[0253] According to some embodiments of this application, please refer to Figures 3 to 14 .

[0254] This application provides a battery cell 20, which includes a housing 21, an electrode assembly 22, electrode terminals 231, and a plurality of first solder joints 24. The housing 21 has a wall portion 213, and the wall portion 213 is provided with a lead-out hole 2131. The electrode assembly 22 is housed within the housing 21, and the electrode assembly 22 has a main body portion 221 and a tab 222, the tab 222 protruding from the main body portion 221. The electrode terminal 231 is disposed on the wall portion 213, and the electrode terminal 231 includes an integrally formed body portion 2312 and a connecting portion 2311. The body portion 2312 passes through the lead-out hole 2131, one end of the body portion 2312 facing the electrode assembly 22 is connected to the connecting portion 2311, and the other end of the body portion 2312 extends out of the lead-out hole 2131 in the direction from the electrode assembly 22 toward the wall portion 213. The connecting portion 2311 is located on the side of the wall portion 213 facing the electrode assembly 22. A connecting portion 2311 is connected to a tab 222 via multiple first solder marks 24, with the multiple first solder marks 24 spaced apart. The electrode terminal 231 includes an integrally formed body portion 2312 and a connecting portion 2311. The body portion 2312 and the connecting portion 2311 have better overall integrity, higher connection stability, and lower resistance. Furthermore, welding the connecting portion 2311 and the tab 222 is more convenient, which helps improve welding quality and reduce the resistance of the first solder marks 24. By connecting a connecting portion 2311 to a tab 222 via multiple first solder marks 24, the welding trajectory for forming a single first solder mark 24 is shorter, the temperature rise is lower, and the deformation of the connecting portion 2311 and the tab 222 is smaller. This helps improve welding quality, reduces the resistance of the first solder marks 24, reduces heat generation of the first solder marks 24 during battery cell 20 operation, and improves the reliability of the battery cell 20. On the other hand, even if some of the first solder marks 24 fail to connect with the connecting part 2311 and the tab 222, the remaining first solder marks 24 can still connect with the connecting part 2311 and the tab 222, and can still achieve overcurrent, which is beneficial to improving the reliability of the battery cell 20.

[0255] In some embodiments, a plurality of first solder marks 24 are arranged around the body portion 2312 of the electrode terminal 231. By arranging the plurality of first solder marks 24 around the body portion 2312 of the electrode terminal 231, on the one hand, current can be transmitted from all sides of the body portion 2312 to the body portion 2312, reducing the risk of excessive current in a single area on the connection portion 2311 leading to overheating. On the other hand, the distances from the plurality of first solder marks 24 to the body portion 2312 are approximately the same, which is beneficial to make the current paths from the plurality of first solder marks 24 to the body portion 2312 approximately the same, and to make the current flowing through the plurality of first solder marks 24 approximately the same, which is beneficial to reducing the risk of excessive current in a single first solder mark 24 leading to overheating of a single first solder mark 24, and is beneficial to improving the reliability of the battery cell 20.

[0256] In other embodiments, a plurality of first solder marks 24 are spaced apart along a first direction, which is perpendicular to the extending direction of the body portion 2312 of the electrode terminal 231. By arranging the plurality of first solder marks 24 spaced apart along the first direction, it is advantageous to increase the distance between two adjacent first solder marks 24, thereby reducing the thermal impact of two adjacent first solder marks 24 and improving the reliability of the battery cell 20.

[0257] In a projection plane perpendicular to the extending direction of the body portion 2312, at least a portion of the projection of at least one first solder mark 24 is located within the projection of the body portion 2312. The projection of at least one first solder mark 24 is located on one side of the projection of the body portion 2312 along the first direction, and the projection of at least one first solder mark 24 is located on the other side of the projection of the body portion 2312 along the first direction. Current can be transmitted from both sides of the body portion 2312 along the first direction, or directly to the body portion 2312 through the first solder mark 24 whose projection is at least partially located within the projection of the body portion 2312. This helps reduce the risk of excessive current in a single area of ​​the connection portion 2311 leading to overheating, and improves the reliability of the battery cell 20.

[0258] The battery cell 20 includes a terminal group 23, which includes multiple electrode terminals 231. The connection portions 2311 of the multiple electrode terminals 231 are all welded to the same tab 222 of the electrode assembly 22. Each terminal group 23 includes multiple electrode terminals 231 with the same polarity. The multiple electrode terminals 231 jointly output or input electrical energy to the battery cell 20, which helps to improve the overcurrent capacity. In this way, the current passing through a single first solder joint 24 is smaller, which helps to reduce the heat generated by a single first solder joint 24 when the battery cell 20 is working, and improves the reliability of the battery cell 20.

[0259] In some embodiments, a plurality of electrode terminals 231 are arranged along a second direction, which is perpendicular to the thickness direction of the wall portion 213. By arranging the plurality of electrode terminals 231 along the second direction, the space of the wall portion 213 along the second direction is utilized as much as possible, and the size of the wall portion 213 in the first direction is reduced, thereby facilitating the control of the size of the battery cell 20.

[0260] In other embodiments, the plurality of electrode terminals 231 include a first electrode terminal 2314, a second electrode terminal 2315, and a third electrode terminal 2316. The first electrode terminal 2314 and the second electrode terminal 2315 are disposed opposite each other along a first direction. In a projection plane perpendicular to the first direction, the projections of the first electrode terminal 2314 and the third electrode terminal 2316 are spaced apart along a second direction, and in a projection plane perpendicular to the second direction, the projection of the third electrode terminal 2316 is located between the projections of the first electrode terminal 2314 and the second electrode terminal 2315. The first direction, the second direction, and the thickness direction of the wall portion 213 are all perpendicular to each other. By arranging the first electrode terminal 2314 and the second electrode terminal 2315 opposite each other along the first direction, and in a projection plane perpendicular to the first direction, the projections of the first electrode terminal 2314 and the third electrode terminal 2316 are spaced apart along the second direction. In a projection plane perpendicular to the second direction, the projection of the third electrode terminal 2316 is located between the projections of the first electrode terminal 2314 and the second electrode terminal 2315, such that the first electrode terminal 2314, the second electrode terminal 2315 and the third electrode terminal 2316 are respectively located at the three vertices of an acute triangle. In this way, the third electrode terminal 2316 can make full use of the space of the wall portion 213 in the first and second directions, which is beneficial to controlling the size of the battery cell 20.

[0261] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A battery cell, characterized in that, include: The outer casing has a wall portion, and the wall portion is provided with an outlet hole; An electrode assembly is housed within the housing, the electrode assembly having a main body and electrode tabs, the electrode tabs protruding from the main body; An electrode terminal is disposed on the wall portion. The electrode terminal includes an integrally formed body portion and a connecting portion. The body portion passes through the lead-out hole. One end of the body portion facing the electrode assembly is connected to the connecting portion. The other end of the body portion extends out of the lead-out hole in the direction of the electrode assembly pointing towards the wall portion. The connecting portion is located on the side of the wall portion facing the electrode assembly. A plurality of first solder marks are provided, and a connecting portion is connected to a tab through the plurality of first solder marks. The plurality of first solder marks are spaced apart.

2. The battery cell according to claim 1, characterized in that, A plurality of the first solder marks are disposed around the body portion of the electrode terminal.

3. The battery cell according to claim 2, characterized in that, The extended trajectory lines of the first solder mark are located on multiple sides of the polygon.

4. The battery cell according to claim 1, characterized in that, A plurality of the first solder marks are spaced apart along a first direction, which is perpendicular to the extension direction of the body portion of the electrode terminal.

5. The battery cell according to claim 4, characterized in that, Each of the first solder marks extends along the second direction, and the first direction, the second direction, and the extension direction of the body portion are perpendicular to each other.

6. The battery cell according to claim 4, characterized in that, In a projection plane perpendicular to the extension direction of the body portion, at least a portion of the projection of at least one of the first solder marks is located within the projection of the body portion, the projection of at least one of the first solder marks is located on one side of the projection of the body portion along the first direction, and the projection of at least one of the first solder marks is located on the other side of the projection of the body portion along the first direction.

7. The battery cell according to claim 1, characterized in that, The electrode tab includes multiple sub-electrodes and a second solder mark, and the multiple sub-electrodes are stacked and connected to each other through the first solder mark and the second solder mark.

8. The battery cell according to any one of claims 1-7, characterized in that, The battery cell includes a terminal group, which includes a plurality of electrode terminals, and the connection portions of the plurality of electrode terminals are all welded to the same tab of the electrode assembly.

9. The battery cell according to claim 8, characterized in that, The terminal group includes a connector located on the side of the wall portion opposite to the electrode assembly, and the connector connects to the body portion of a plurality of the electrode terminals.

10. The battery cell according to claim 9, characterized in that, The connector, the main body, and the connecting part are integrally formed.

11. The battery cell according to claim 8, characterized in that, Any two electrode terminals in the terminal group are not connected to each other.

12. The battery cell according to claim 8, characterized in that, The plurality of electrode terminals in the terminal group are disposed on the same wall portion of the housing.

13. The battery cell according to claim 12, characterized in that, The plurality of electrode terminals are arranged along a second direction, which is perpendicular to the thickness direction of the wall portion.

14. The battery cell according to claim 13, characterized in that, Along the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, the pole lug protrudes from one end of the main body portion facing the wall portion, and the length direction of the wall portion is parallel to the second direction; Along the second direction, the wall portion has a dimension of L, and the tab has a dimension of W, satisfying: 0.125≤W / L≤0.

5.

15. The battery cell according to claim 14, characterized in that, 0.165≤W / L≤0.

25.

16. The battery cell according to claim 13, characterized in that, Along the thickness direction of the wall portion, the orthographic projection of the wall portion is rectangular, the pole lug protrudes from one end of the main body portion facing the wall portion, and the length direction of the wall portion is parallel to the second direction; The length of the first solder mark is A, and the size of the electrode tab along the second direction is W, satisfying: 0.1≤A / W≤0.

5.

17. The battery cell according to claim 16, characterized in that, 0.25≤A / W≤0.

35.

18. The battery cell according to claim 13, characterized in that, Along the thickness direction of the wall portion, the orthographic projection of the wall portion is a rectangle, the pole lug protrudes from the end of the main body portion facing the wall portion, the width direction of the wall portion is parallel to the first direction, and the length direction of the wall portion is parallel to the second direction; Along the first direction, the dimension of the wall is D, and along the second direction, the dimension of the wall is L, satisfying: 5≤L / D≤25.

19. The battery cell according to claim 18, characterized in that, 10≤L / D≤20.

20. The battery cell according to claim 18, characterized in that, 50mm≤L≤500mm.

21. The battery cell according to claim 20, characterized in that, 100mm≤L≤350mm.

22. The battery cell according to claim 12, characterized in that, The plurality of electrode terminals include a first electrode terminal, a second electrode terminal, and a third electrode terminal. The first electrode terminal and the second electrode terminal are arranged opposite each other along a first direction. In a projection plane perpendicular to the first direction, the projections of the first electrode terminal and the third electrode terminal are spaced apart along a second direction. In a projection plane perpendicular to the second direction, the projection of the third electrode terminal is located between the projections of the first electrode terminal and the second electrode terminal. The first direction, the second direction, and the thickness direction of the wall are all perpendicular to each other.

23. The battery cell according to claim 12, characterized in that, Along the thickness direction of the wall portion, the electrode lug protrudes from the end of the main body portion facing the wall portion; The battery cell includes multiple electrode assemblies, which are arranged along a first direction. The tabs of the multiple electrode assemblies have overlapping areas stacked along the thickness direction of the wall. Multiple electrode terminals are welded to the same overlapping area. The connection portion of each electrode terminal is connected to the overlapping area through multiple first solder marks. The first direction is perpendicular to the thickness direction of the wall.

24. The battery cell according to claim 12, characterized in that, The battery cell includes two terminal groups, and the electrode terminals in the two terminal groups have opposite polarities.

25. The battery cell according to claim 24, characterized in that, The electrode terminals of the two terminal groups are disposed on the same wall of the housing.

26. The battery cell according to any one of claims 1-7, characterized in that, The electrode assembly is a wound electrode assembly.

27. A battery device, characterized in that, Includes the battery cell according to any one of claims 1-26.

28. An electrical appliance, characterized in that, Includes a battery cell according to any one of claims 1-26, the battery cell being used to provide electrical energy to the electrical device.

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