Battery cells, batteries, and electrical devices

Abstract

A battery cell, a battery, and an electric device are provided that can effectively improve the performance and safety of use of a battery. [Solution] The battery cell of the present application comprises a housing, an end cover, an electrode assembly, a first current collecting member (24), and a second current collecting member (25), wherein the housing has an opening and the end cover is installed to cover the opening, the electrode assembly is accommodated within the housing and has a tab, the first current collecting member (24) and the second current collecting member (25) are configured as separate entities, the first current collecting member (24) is connected to the tab, and the second current collecting member (25) is connected to the end cover, the first current collecting member (24) and the second current collecting member (25) are connected in an overlapping relationship along the thickness direction of the end cover, the second current collecting member (25) is located on the side of the first current collecting member (24) facing the end cover, and the projection of the second current collecting member (25) is located within the outer edge of the first current collecting member (24).

Description

Technical Field

[0001] (Cross - reference to related applications) This application claims priority based on a Chinese application named "Battery Cell, Battery and Electric Device" with an application number of 202210521640.1 filed on May 13, 2022, and all of its content is incorporated herein by reference.

[0002] This application belongs to the technical field of batteries, and specifically relates to battery cells, batteries, and electric devices.

Background Art

[0003] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries play an important role as the power source of electric vehicles. With the popularization of new energy vehicles, the demand for power battery products is also increasing. Batteries, as the core components of new energy vehicles, have high requirements in terms of use performance and use safety. A battery cell of a battery is obtained by assembling an electrode assembly (bare cell) in a winding or stacking manner from a positive electrode plate, a negative electrode plate, and a separator, putting it into a housing, further covering it with an end cover, and injecting an electrolyte. However, the batteries according to the prior art have poor use performance during the use process and relatively large safety problems, so they are disadvantageous for popularization and use.

Summary of the Invention

[0004] Embodiments of this application provide a battery cell, a battery, and an electric device that can effectively improve the use performance and use safety of the battery.

[0005] In the first aspect, an embodiment of the present application provides a battery cell. The battery cell comprises a housing, an end cover, an electrode assembly, a first current collector member, and a second current collector member, wherein the housing has an opening, the end cover is installed to cover the opening, the electrode assembly is housed within the housing and has a tab, the first current collector member and the second current collector member are configured separately from each other, the first current collector member is connected to the tab, the second current collector member is connected to the end cover, the first current collector member and the second current collector member are connected in an overlapping manner along the thickness direction of the end cover, the second current collector member is located on the side of the first current collector member facing the end cover, and the projection of the second current collector member is located within the outer edge of the first current collector member.

[0006] In the above proposed technology, the first current collector and the second current collector are installed between the electrode assembly and the end cover so as to overlap along the thickness direction of the end cover, and are connected to each other. This connects the first current collector to the tab of the electrode assembly, and after the second current collector is connected to the end cover, an electrical connection can be achieved between the electrode assembly and the end cover. The projection of the second current collector in the thickness direction of the end cover is located within the outer edge of the first current collector, meaning that the area of ​​the first current collector is larger than the area of ​​the second current collector. This allows the second current collector and the end cover to be assembled during the battery cell assembly process. In this way, the area of ​​the first current collector is not limited by the end cover, which contributes to reducing the difficulty of connecting the first current collector and the tab, and contributes to increasing the connection area and improving the stability of the connection. On the other hand, the contact resistance between the first current collector and the tab is reduced, which contributes to a decrease in the charge / discharge rate of the battery cell and improves the operating performance of the battery cell. On the other hand, it reduces the occurrence of localized overcurrent between the first current collector and the tab, which contributes to reducing the risk of temperature rise inside the battery cell and improves the safety of using the battery cell.

[0007] In some embodiments, the area defined by the outer edge of the first current collector is S1, and the area defined by the outer edge of the second current collector is S2, and S1 and S2 satisfy the condition 0.6 ≤ S2 / S1 ≤ 0.9.

[0008] In the above proposed technology, if the ratio of the areas of the second current collector to the first current collector is set to 0.6 to 0.9, on the one hand, the influence of the second current collector on the end cover during assembly due to the excessive area of ​​the second current collector can be reduced, thereby improving the ease of assembly between the end cover and the second current collector. On the other hand, the problem of insufficient current conduction area between the first current collector and the second current collector due to the insufficient area of ​​the second current collector can be mitigated.

[0009] In some embodiments, both the first current collector and the second current collector are circular in shape, the outer diameter of the first current collector is D1, the outer diameter of the second current collector is D2, and D1 and D2 satisfy the condition D1 > D2.

[0010] In the above proposed technology, making the first and second current collectors circular in shape would facilitate manufacturing and reduce the difficulty of assembly.

[0011] In some embodiments, the electrode assembly includes a main body, the tabs are provided to protrude from the end of the main body facing the end cover, the main body is cylindrical, the outer diameter of the main body is D3, and the conditions 0.1mm ≤ D3-D1 ≤ 5mm and 5mm ≤ D3-D2 ≤ 10mm are satisfied.

[0012] In the above proposed technology, if the difference between the diameter of the main body of the electrode assembly and the diameter of the first current collector is set to 0.1 mm to 5 mm, on the one hand, interference between the first current collector and the housing caused by an excessively large first current collector can be suppressed, and on the other hand, insufficient connection area between the first current collector and the tab caused by an undersized first current collector can be mitigated, thereby ensuring a sufficient current conduction area between the first current collector and the tab. Similarly, if the difference between the diameter of the main body and the diameter of the second current collector is set to 5 mm to 10 mm, on the one hand, interference effects that the second current collector has on the end cover during assembly caused by an excessively large second current collector can be mitigated, and on the other hand, insufficient current conduction area between the second current collector and the first current collector caused by an undersized second current collector can be suppressed.

[0013] In some embodiments, at least one first welding groove is provided on the surface of the first current collector facing the second current collector along the thickness direction of the end cover, a first welding region is formed on the first current collector at the position where the first welding groove is provided, and the first welding region is welded to the tab.

[0014] In the above proposed technology, a first welding groove is provided in the first current collector member, and a first welding region is formed at the location of the first welding groove where the tab is welded. With this structure, on the one hand, the first welding groove plays a positioning role when welding the first current collector member and the tab, making welding easier and improving welding accuracy, and on the other hand, it contributes to penetrating the first current collector member during welding, thereby contributing to guaranteeing the quality of the weld.

[0015] In some embodiments, the area defined by the outer edge of the first current collector is S1, the total area of ​​the first welding region of the first current collector is S3, and S1 and S3 satisfy the condition 0.05 ≤ S3 / S1 ≤ 0.3.

[0016] In the above proposed technology, if the ratio of the total area of ​​the first welding region to the area of ​​the first current collector is set to 0.05 to 0.3, on the one hand, the shortage of welding area between the first current collector and the tab caused by an insufficient total area of ​​the first welding region can be suppressed, and on the other hand, the shortage of area in the first current collector for connecting to the second current collector caused by an excessive area occupied by the first welding region in the first current collector can be mitigated.

[0017] In some embodiments, the first welding groove extends along the radial direction of the first current collector.

[0018] In the above proposed technology, if the first welding groove extends along the radial direction of the first current collector, the first welding groove can pass through the center of the first current collector, meaning that the first welding area can pass through the center of the first current collector, thereby contributing to an increase in the welding area between the first current collector and the tab.

[0019] In some embodiments, both ends of the first welding groove penetrate the outer edge of the first current collector.

[0020] In the above proposed technology, both ends of the first welding groove penetrate the outer edge of the first current collector member. As a result, the first welding region formed by the first welding groove extends from the center of the first current collector member to the outer edge of the first current collector member, ensuring the welding area and welding stability between the first current collector member and the tab, and improving the effect of current conduction between the first current collector member and the tab.

[0021] In some embodiments, the first current collector member is provided with a plurality of first welding grooves, the plurality of first welding grooves intersect at an intersection point, the plurality of first welding grooves divide the first current collector member into a plurality of main regions, the plurality of main regions are spaced apart around the intersection point, and at least one of the main regions is connected to the second current collector member.

[0022] In the above technical solution, a plurality of first welding grooves are provided in the first current collecting member, and the plurality of first welding grooves intersect at one intersection position. According to the first current collecting member having this configuration, on the one hand, the welding area between the first current collecting member and the tab can be further increased, and on the other hand, the main body regions formed by partitioning with the plurality of first welding grooves are connected to the second current collecting member, contributing to a reduction in the difficulty of connection between the first current collecting member and the second current collecting member.

[0023] In some embodiments, the intersection position is the central position of the first current collecting member.

[0024] In the above technical solution, if the plurality of first welding grooves intersect at the central position of the first current collecting member, it can ensure that the tab can be welded to the first current collecting member at different positions in the radial direction of the first current collecting member, improving the welding area and welding stability, and thereby effectively improving the current conduction performance between the tab and the first current collecting member.

[0025] In some embodiments, a first central hole is provided at the intersection position, the first central hole penetrates both sides of the first current collecting member along the thickness direction of the end cover, and the diameter of the first central hole is equal to the width of the first welding groove.

[0026] In the above technical solution, by providing a first central hole at the intersection position where the plurality of first welding grooves intersect and making the diameter of the first central hole the same as the width of the first welding groove, on the one hand, the electrolyte can be guided to a certain extent, improving the wetting effect of the electrolyte on the electrode assembly, and on the other hand, it contributes to guiding and discharging the gas generated inside the battery cell or the smoke generated during welding through the first central hole and the first welding groove, improving the use performance of the battery cell.

[0027] In some embodiments, a plurality of current guiding holes are provided in at least one of the main body regions, and the current guiding holes penetrate both sides of the first current collecting member along the thickness direction of the end cover.

[0028] In the above technical solution, by providing a diversion hole in the main body area of the first current collector member, the electrolyte is allowed to enter the tab along the axial direction of the electrode assembly through the diversion hole, contributing to the improvement of the wetting effect of the electrolyte on the electrode assembly.

[0029] In some embodiments, the area defined by the outer edge of the first current collector member is S1, the total area of the plurality of diversion holes is S4, and S1 and S4 satisfy 0.2 ≤ S4 / S1 ≤ 0.5.

[0030] In the above technical solution, if the ratio of the total area of the diversion holes to the area of the first current collector member is 0.2 to 0.5, on the one hand, it can alleviate the poor diversion effect on the electrolyte caused by the too small total area of the diversion holes, and on the other hand, it can reduce the risks of insufficient structural strength of the first current collector member and insufficient welding area between the first current collector member and the tab caused by the too large area of the first current collector member occupied by the diversion holes.

[0031] In some embodiments, the aperture diameter of the diversion hole is D4, and D4 satisfies 0.1 mm ≤ D4 ≤ 10 mm.

[0032] In the above technical solution, if the aperture diameter of the diversion hole is 0.1 mm to 10 mm, on the one hand, it can reduce the risk of insufficient structural strength of the first current collector member caused by the too large aperture diameter of the diversion hole, and on the other hand, it can improve the situation of difficult passage of the electrolyte caused by the too small aperture diameter of the diversion hole.

[0033] In some embodiments, there are two first welding grooves, and the first current collector member is partitioned into four main body areas by the two first welding grooves. Among the four main body areas, two opposite main body areas are connected to the second current collector member, and the diversion holes are provided in the other two opposite main body areas.

[0034] In the above proposed technology, the first current collector member is provided with two first welding grooves, and the two welding grooves divide the first current collector member into four main regions, two opposing main regions are connected to the second current collector member, and guide holes are provided in the other two opposing main regions. Such a structure is simple and therefore easy to implement, and can contribute to reducing the difficulty of processing the first current collector member and the difficulty of assembling the battery cell.

[0035] In some embodiments, at least one second welding groove is provided on the surface of the second current collector facing the end cover along the thickness direction of the end cover, a second welding region is formed on the second current collector at the position where the second welding groove is provided, and the second welding region and the first current collector are welded together.

[0036] In the above proposed technology, a second welding groove is provided in the second current collector member, and a second welding region for welding with the first current collector member is formed at the location of the second welding groove. With this structure, on the one hand, the second welding groove plays a positioning role when welding the second current collector member and the first current collector member, making it easier to weld the second current collector member and the first current collector member. On the other hand, it contributes to penetrating the second current collector member during welding, thereby contributing to ensuring the quality of the weld between the second current collector member and the first current collector member.

[0037] In some embodiments, a plurality of first welding grooves are provided on the surface of the first current collector facing the second current collector along the thickness direction of the end cover, the plurality of first welding grooves intersect at the center of the first current collector, the plurality of first welding grooves divide the first current collector into a plurality of main regions, each second welding region is welded to one of the main regions, and the projection of each second welding groove in the thickness direction of the end cover is located within the corresponding main region.

[0038] In the above proposed technology, the first current collector member is provided with a plurality of first welding grooves, and the first current collector member is divided into a plurality of main regions by the plurality of welding grooves, and the main regions are welded to a second welding region formed by a second welding groove in the second current collector member, thereby allowing the projection of the second welding groove in the thickness direction of the end cover to be contained within the corresponding main region. With such a structure, the difficulty of welding the second current collector member and the first current collector member is reduced, and interference between the second current collector member and the first welding groove of the first current collector member when the second current collector member is welded to the first current collector member can be suppressed.

[0039] In some embodiments, the area defined by the outer edge of the second current collector is S2, the total area of ​​the second welding region of the second current collector is S5, and S2 and S5 satisfy the condition 0.05 ≤ S5 / S2 ≤ 0.3.

[0040] In the above proposed technology, if the ratio of the total area of ​​the second welding region to the area of ​​the second current collector is set to 0.05 to 0.3, it is possible to suppress insufficient current conduction caused by insufficient connection area between the second current collector and the first current collector, and to mitigate insufficient connection area between the second current collector and the end cover caused by excessive area occupied by the second welding region.

[0041] In the second aspect, embodiments of the present application further provide a battery, the battery comprising a housing and the battery cells described above, wherein the battery cells are housed within the housing.

[0042] In the third aspect, embodiments of the present application further provide an electrical device, the electrical device including the battery described above.

[0043] To more clearly explain the technical concept of the embodiments of this application, the drawings used in the embodiments are briefly described below. The drawings described are merely examples of some embodiments of this application and do not limit their scope. Those skilled in the art can obtain other relevant drawings based on these drawings without employing inventive ability. [Brief explanation of the drawing]

[0044] [Figure 1] This is a schematic diagram of a vehicle according to some embodiments of this application. [Figure 2] This is an exploded view showing the configuration of a battery according to several embodiments of this application. [Figure 3] This is an exploded view showing the configuration of a battery cell according to several embodiments of this application. [Figure 4] This is a partial cross-sectional view of a battery cell according to some embodiments of this application. [Figure 5] This is a schematic diagram showing the connection between a first current collector and a second current collector according to some embodiments of this application. [Figure 6] This is a plan view of a first current collector according to several embodiments of this application. [Figure 7] This is a plan view of a second current collector according to some embodiments of the present application. [Figure 8] This is a plan view of a second current collector member connected to a first current collector member according to some embodiments of this application. [Modes for carrying out the invention]

[0045] To clarify the purpose, technical concept, and advantages of the embodiments of this application, the technical concept in the embodiments of this application will be clearly described below with reference to the drawings used in the embodiments of this application. The embodiments described are only a few of the embodiments of this application, not all of them. All embodiments that a person skilled in the art could obtain without using their inventive ability based on the embodiments of this application also fall within the scope of protection of this application.

[0046] Unless otherwise specified, all technical and scientific terms used in this application have the meanings that a person skilled in the art would ordinarily understand. The terms used in this application are for illustrative purposes only and do not limit this application. The terms “includes,” “has,” and any variations thereof in the description, claims, and description of the drawings above have a non-exclusive meaning. Terms such as “first,” “second,” etc., in the description, claims, and description of the drawings above are for distinguishing different elements and do not prescribe any particular order or principal / secondary status.

[0047] Where the term “Examples” is used in this application, it means that the specific features, configurations, or characteristics described using the Examples are included in at least one Example of this application. Where this term is used in any part of the Specification, it does not necessarily refer to the same Example, nor is it intended to limit any independent or alternative Example to any other Example.

[0048] In the description of this application, unless otherwise specified, the terms “attachment,” “connection,” “connection,” and “installation” should be understood in a broad sense. For example, it could be a fixed connection, a removable connection, or an integral connection. It could be a direct connection, an indirect connection via an intermediate object, or the interiors of two elements could be in communication. A person skilled in the art will be able to understand the specific meaning of the above terms in this application depending on the specific situation.

[0049] The terms "and / or" used in this application are merely for describing the relationship between related objects and represent three types of relationships. For example, A and / or B can represent three situations: A existing alone, A and B existing simultaneously, or B existing alone. The symbol " / " in this application generally indicates a relationship between the preceding and following related objects indicated by "or".

[0050] In the embodiments of this application, similar reference numerals indicate similar parts, and for simplicity, detailed descriptions of similar parts are omitted in different embodiments. The dimensions, such as thickness and length, of various parts in the embodiments of this application shown in the drawings, and the dimensions, such as thickness and length, of the entire assembly device, are for illustrative purposes only and do not limit this application.

[0051] In this application, "multiple" means two or more (including two).

[0052] In this application, battery cells include, but are not limited to, lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries. Battery cells may be cylindrical, flattened, rectangular, or other shapes, and are not limited to these shapes. Battery cells are generally classified into three types based on their packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and are not limited to these shapes.

[0053] The batteries described in the embodiments of this application refer to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the batteries described in this application include battery modules or battery packs. Batteries generally include a housing for packaging one or more battery cells or multiple battery modules. The housing can prevent liquids or other foreign matter from affecting the charging and discharging of the battery cells.

[0054] A battery cell comprises a housing, an electrode assembly, and an electrolyte, with the housing configured to accommodate the electrode assembly and the electrolyte. The electrode assembly consists of a positive electrode plate, a negative electrode plate, and a separator. The battery cell functions primarily through the movement of metal ions between the positive and negative electrode plates. The positive electrode plate comprises a positive electrode current collector and a positive electrode active material layer, with the positive electrode active material layer coated on the surface of the positive electrode current collector. The uncoated portion of the positive electrode active material layer on the positive electrode current collector serves as the positive electrode tab, which enables the input and output of electrical energy to the positive electrode plate. Taking lithium-ion batteries as an example, the material of the positive electrode current collector is aluminum, and the positive electrode active material is lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide, etc. The negative electrode plate includes a negative electrode current collector and a negative electrode active material layer. The negative electrode active material layer is coated on the surface of the negative electrode current collector, and the uncoated portion of the negative electrode current collector is designated as a negative electrode tab. The negative electrode tab enables the input and output of electrical energy to the negative electrode plate. The negative electrode current collector may be made of copper, and the negative electrode active material may be carbon-based or silicon-based. To ensure that they do not melt when a large current flows, the positive electrode tabs are made of multiple layers, and the negative electrode tabs are also made of multiple layers.

[0055] The separator material may be PP (polypropylene) or PE (polyethylene), etc. Furthermore, the electrode assembly may have a wound structure or a laminated structure, and the embodiments of this application are not limited to these.

[0056] Batteries have advantages such as high energy density, low environmental pollution, high power density, long service life, wide range of applications, and low self-discharge coefficient, making them an important component in the development of new energy sources. A battery cell is obtained by assembling an electrode assembly (bare cell) from a positive electrode plate, a negative electrode plate, and a separator using methods such as winding or lamination, placing it in a housing, covering it with an end cover, and injecting an electrolyte. However, with the development of battery technology, the demands on battery performance and safety are becoming higher. Therefore, the performance and safety of a battery are determined by the performance and safety of the battery cell.

[0057] As the inventors have found, in a typical battery cell, the electrode assembly is electrically connected to the end cover by connecting the tabs of the electrode assembly to the end cover, thereby making the end cover the positive or negative output electrode of the battery cell. To facilitate the electrical connection between the electrode assembly tabs and the end cover, a current collector plate is usually installed inside the housing, and the current collector plate is connected to both the end cover and the tabs of the electrode assembly (the tabs are full tabs, flattened and connected to the current collector plate), thereby achieving the electrical connection between the electrode assembly and the end cover. The larger the feed amount required to flatten the tab (i.e., the greater the amount of pressure applied to flatten the tab), the larger the tab area becomes, but the larger the feed amount required to flatten, the more difficult it becomes to weld the tab to the current collector plate, and the stability of the weld between the tab and the current collector plate is compromised. In conventional technology, to ensure the effectiveness of the electrical connection between the electrode assembly and the end cover, a panel sleeve is fitted around the outer circumference of the current collector plate. This protects the current collector plate and increases its diameter, ensuring that welding can reach the outermost tab during welding. The increased diameter also allows the welding area to be further extended to the edge of the winding core, thereby reducing the internal resistance of the battery cell. However, because the current collector plate of this structure is affected by the end cover, the area of ​​the current collector plate is relatively small, the difficulty of welding the current collector plate to the tab remains relatively high, welding defects between the current collector plate and the tab of the electrode assembly are likely to occur, which is detrimental to improving the stability of the connection between the current collector plate and the tab. Consequently, on the one hand, the contact resistance between the current collector plate and the tab of the electrode assembly remains relatively high, the charge and discharge rate of the battery cell is relatively high, which is detrimental to improving the operating performance of the battery cell. On the other hand, localized overcurrents are likely to occur between the current collector plate and the tab of the electrode assembly during use, leading to a risk of temperature rise inside the battery cell, which is detrimental to improving the safety of the battery cell during use.

[0058] In view of the above, in order to solve the problem of relatively low performance and safety in use that exists in battery cells, the inventors have diligently conducted research and designed a battery cell comprising a housing, an end cover, an electrode assembly, a first current collector member, and a second current collector member. The housing has an opening, and the end cover is installed so as to cover the opening. The electrode assembly is housed within the housing and has tabs. The first current collector member and the second current collector member are configured separately from each other, with the first current collector member connected to the tabs and the second current collector member connected to the end cover. Along the thickness direction of the end cover, the first current collector member and the second current collector member are connected in an overlapping manner, with the second current collector member located on the side of the first current collector member facing the end cover, and the projection of the second current collector member located within the outer edge of the first current collector member.

[0059] In the above-described battery cell, the first current collector and the second current collector are installed between the electrode assembly and the end cover so as to overlap along the thickness direction of the end cover, and are connected to each other. This connects the first current collector to the tab of the electrode assembly, and after the second current collector is connected to the end cover, an electrical connection can be achieved between the electrode assembly and the end cover. The projection of the second current collector in the thickness direction of the end cover is located within the outer edge of the first current collector, meaning that the area of ​​the first current collector is larger than the area of ​​the second current collector. This allows the second current collector and the end cover to be assembled during the battery cell assembly process. In this way, the area of ​​the first current collector is not limited by the end cover, which contributes to reducing the difficulty of connecting the first current collector and the tab, and contributes to increasing the connection area and improving the stability of the connection. On the other hand, the contact resistance between the first current collector and the tab is reduced, which contributes to a decrease in the charge / discharge rate of the battery cell and improves the operating performance of the battery cell. On the other hand, it reduces the occurrence of localized overcurrent between the first current collector and the tab, which contributes to reducing the risk of temperature rise inside the battery cell and improves the safety of using the battery cell.

[0060] The battery cells according to the embodiments of this application can be used in electrical devices such as vehicles, ships, or aircraft, but are not limited to these. By using the battery cells and batteries according to this application to configure a power supply system for such electrical devices, the stability and reliability of the connection between the current collector and the electrode assembly can be effectively improved, thereby improving the performance and safety of the battery cells.

[0061] Embodiments of this application provide battery-powered electrical devices. Electrical devices include, but are not limited to, mobile phones, tablets, laptop computers, electric toys, power tools, electric cars, electric vehicles, ships, and aircraft. Electric toys include stationary or mobile devices, such as game consoles, electric car toys, electric boat toys, and electric airplane toys. Aircraft include airplanes, rockets, space shuttles, and spacecraft.

[0062] For the sake of explanation, in the following embodiment, the electrical device according to one embodiment of this application will be described using vehicle 1000 as an example.

[0063] Figure 1 is a schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 includes fuel-powered vehicles, natural gas vehicles, or new energy vehicles, the new energy vehicles including electric vehicles, hybrid vehicles, or range-extender electric vehicles. A battery 100 is located inside the vehicle 1000, and the battery 100 is located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000, for example, as a power source for the vehicle 1000's operation. The vehicle 1000 further comprises a control device 200 and an engine 300, the control device 200 controlling the power supply from the battery 100 to the engine 300, which is used, for example, to power the vehicle 1000 for starting, navigation, and operation while driving.

[0064] In some embodiments of this application, the battery 100 can be used not only as a power source for steering the vehicle 1000, but also as a power source to provide driving power to the vehicle 1000 in place of or in part of gasoline or natural gas.

[0065] Figure 2 is an exploded view showing the configuration of a battery 100 according to some embodiments of the present application. The battery 100 includes a housing 10 and battery cells 20, the battery cells 20 being housed within the housing 10. The housing 10 provides assembly space for the battery cells 20 and can be used in various configurations. In some embodiments, the housing 10 includes a first housing body 11 and a second housing body 12, the first housing body 11 and the second housing body 12 together define assembly space for housing the battery cells 20. The second housing body 12 may be a hollow structure with one end open, and the first housing body 11 may be a plate-like structure, with the first housing body 11 installed so as to cover the open side of the second housing body 12, and the assembly space may be defined by the first housing body 11 and the second housing body 12. Alternatively, both the first housing body 11 and the second housing body 12 may be hollow structures with one side open, with the open side of the first housing body 11 installed so as to cover the open side of the second housing body 12. Of course, the housing 10 formed by the first housing body 11 and the second housing body 12 can be of various shapes such as a cylinder or a rectangular prism.

[0066] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a manner that includes both. Connecting in a manner that includes both means that among the multiple battery cells 20, some are connected in series and others are connected in parallel. Multiple battery cells 20 may be directly connected in series, in parallel, or in a manner that includes both, and the integrated unit consisting of multiple battery cells 20 may be housed in the housing 10. Alternatively, the battery 100 may first connect multiple battery cells 20 in series, in parallel, or in a manner that includes both to form a battery module, and then further connect multiple battery modules in series, in parallel, or in a manner that includes both to form an integrated unit, which may be housed in the housing 10. The battery 100 may further include other structures, for example, the battery 100 further includes busbar members for realizing electrical connections between multiple battery cells 20.

[0067] Each battery cell 20 may be a secondary battery or a primary battery, and may be, but is not limited to, a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery. The battery cell 20 may be cylindrical, flattened, rectangular, or other shapes. Exemplarily, as shown in Figure 2, the battery cell 20 is cylindrical.

[0068] In some embodiments of this application, with reference to Figures 3, 4, and 5, Figure 3 is an exploded view showing the configuration of a battery cell 20 according to some embodiments of this application, Figure 4 is an exploded view showing the configuration of a current collector according to some embodiments of this application, and Figure 5 is a schematic diagram showing the connection between a first current collector 24 and a second current collector 25 according to some embodiments of this application. This application provides a battery cell 20 comprising a housing 21, an end cover 22, an electrode assembly 23, a first current collector 24, and a second current collector 25. The housing 21 has an opening 211, and the end cover 22 is installed so as to cover the opening 211. The electrode assembly 23 is housed in the housing 21 and has tabs 231. The first current collector 24 and the second current collector 25 are configured separately from each other, with the first current collector 24 connected to the tabs 231 and the second current collector 25 connected to the end cover 22. Along the thickness direction X of the end cover, the first current collector 24 and the second current collector 25 are connected in an overlapping manner, with the second current collector 25 located on the side of the first current collector 24 facing the end cover 22, and the projection of the second current collector 25 located within the outer edge of the first current collector 24.

[0069] Along the thickness direction X of the end cover, the first current collector 24 and the second current collector 25 are connected in an overlapping manner, with the second current collector 25 positioned on the side of the first current collector 24 facing the end cover 22. In other words, the first current collector 24 and the second current collector 25 are installed between the electrode assembly 23 and the end cover 22 so as to overlap along the thickness direction X of the end cover, and the first current collector 24 is further from the end cover 22 than the second current collector 25.

[0070] The projection of the second current collector 25 is said to be located within the outer edge of the first current collector 24, which means that, along the thickness direction X of the end cover, the projection of the second current collector 25 is located within the region defined by the outer edge of the first current collector 24, that is, the area of ​​the second current collector 25 is smaller than that of the first current collector 24.

[0071] Optionally, the connections between the first current collector 24 and the tab 231, the first current collector 24 and the second current collector 25, and the second current collector 25 and the end cover 22 may be by contact or by welding. Exemplaryly, in this embodiment, the first current collector 24 and the tab 231 are welded, the first current collector 24 and the second current collector 25 are welded, and the second current collector 25 and the end cover 22 are welded.

[0072] For example, the materials used for the first current collector 24 and the second current collector 25 can be various materials, such as copper, nickel, or aluminum. The thickness of both the first current collector 24 and the second current collector 25 is 0.1 mm to 5 mm.

[0073] Optionally, the housing 21 also houses an electrolyte, for example, an electrolyte solution. The housing 21 can be constructed in various forms. The housing 21 can be made of various materials such as copper, iron, aluminum, steel, and aluminum alloys.

[0074] When assembling the battery cell 20, the electrode assembly 23 is first placed into the housing 21, the electrolyte is filled into the housing 21, and then the end cover 22 is placed over the opening 211 of the housing 21 to form a sealed connection and create a sealed space that houses the electrode assembly 23 and the electrolyte. Exemplarily, the end cover 22 is welded to the housing 21.

[0075] An insulating member 221 is installed on the end cover 22, and the insulating member 221 is located on the side of the end cover 22 facing the electrode assembly 23. During the process of assembling the battery cell 20, when the end cover 22 is installed to cover the opening 211 of the housing 21, the insulating member 221 covers the outer circumference of the second current collector 25, thereby providing insulating protection and positioning for the second current collector 25 during installation. For example, the insulating member 221 may be made of various materials such as rubber, plastic, or silicone rubber.

[0076] The housing 21 can be of various shapes, such as a cylinder or a rectangular prism. The shape of the housing 21 is determined based on the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 has a cylindrical structure, the housing 21 will have a cylindrical structure, and if the electrode assembly 23 has a rectangular prism structure, the housing 21 will have a rectangular prism structure. Exemplarily, in Figure 3, since the electrode assembly 23 has a cylindrical structure, the housing 21 is cylindrical.

[0077] Exemplary, in Figure 3, the housing 21 is a hollow structure with one end open, and the end cover 22 is installed so as to cover the opening 211 of the housing 21 to form a sealed connection, creating a sealed space for housing the electrode assembly 23 and the electrolyte. Electrode terminals 222 are installed on the end cover 22, and the electrode terminals 222 and the end cover 22 are insulated from each other, meaning that no current is conducted between the electrode terminals 222 and the end cover 22. The electrode assembly 23 has tabs 231 (positive electrode tab and negative electrode tab, respectively) at both ends in the thickness direction X of the end cover, and the two tabs 231 are connected to the electrode terminals 222 and the ends of the housing 21 spaced away from the end cover 22, respectively, and serve as the positive output electrode and negative output electrode of the battery cell 20. Of course, the tab 231 and the electrode terminal 222 or housing 21 may be directly connected, such as by welding or abutment, or the tab 231 may be connected via other parts, for example, by welding or abutment with other parts before connecting to the electrode terminal 222 or housing 21.

[0078] Along the thickness direction X of the end cover, the tab 231 at the end of the electrode assembly 23 facing the end cover 22 is connected to the first current collector 24, and the second current collector 25 is connected to the electrode terminal 222 of the end cover 22. The second current collector 25 is directly connected to the electrode terminal 222 of the end cover 22, for example, by welding or abutting the second current collector 25 directly to the electrode terminal 222 to achieve electrical connection between the second current collector 25 and the electrode terminal 222. Of course, the second current collector 25 may also be indirectly connected to the electrode terminal 222 of the end cover 22, for example, by welding or abutting the second current collector 25 to an intermediate member, and then welding or abutting the intermediate member to the electrode terminal 222.

[0079] The battery cell 20 is not limited to the above configuration and may have other configurations. For example, the battery cell 20 includes a housing 21 and two end covers 22, the housing 21 being a hollow structure with open ends, and each end cover 22 is positioned to cover one opening 211 of the housing 21 to form a sealed connection, thereby creating a sealed space for housing the electrode assembly 23 and electrolyte. In an embodiment where the housing 21 is a hollow structure with open ends, electrode terminals 222 are provided on each of the two end covers 22, and the two electrode terminals 222 are connected to two tabs 231 of the electrode assembly 23, respectively, to become the positive output electrode and negative output electrode of the battery cell 20. Furthermore, in the battery cell 20 with this configuration, the first current collector 24 and the second current collector 25 may be installed only between one end cover 22 and the electrode assembly 23, or the first current collector 24 and the second current collector 25 may be installed between each end cover 22 and the electrode assembly 23, and the embodiment of this application is not limited thereto.

[0080] The electrode assembly 23 is a component in the battery cell 20 where an electrochemical reaction occurs. The electrode assembly 23 includes a positive electrode plate, a negative electrode plate, and a separator. The electrode assembly 23 may be a wound structure formed by winding the positive electrode plate, separator, and negative electrode plate, or a laminated structure formed by stacking the positive electrode plate, separator, and negative electrode plate. Exemplarily, in Figure 3, the electrode assembly 23 is a wound structure formed by winding the positive electrode plate, separator, and negative electrode plate.

[0081] In some embodiments, as shown in Figure 3, the battery cell 20 further includes a pressure relief mechanism 223, which may be attached to an end cover 22 or to a housing 21. The pressure relief mechanism 223 is configured to release the internal pressure of the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0082] Exemplary examples, the pressure relief mechanism 223 may be a component such as an explosion-proof valve, a rupture disc, an air valve, a pressure relief valve, or a safety valve.

[0083] The first current collector 24 and the second current collector 25 are installed between the electrode assembly 23 and the end cover 22, overlapping along the thickness direction X of the end cover, and connected to each other. This connects the first current collector 24 to the tab 231 of the electrode assembly 23, and after the second current collector 25 is connected to the end cover 22, an electrical connection between the electrode assembly 23 and the end cover 22 can be achieved. The projection of the second current collector 25 in the thickness direction X of the end cover is located within the outer edge of the first current collector 24. In other words, the area of ​​the first current collector 24 is larger than the area of ​​the second current collector 25. This means that when assembling the battery cell 20, the second current collector 25 and the end cover 22 can be assembled together. In this way, the area of ​​the first current collector 24 is not limited by the end cover 22, which reduces the difficulty of connecting the first current collector 24 to the tab 231, and contributes to increasing the connection area and improving the stability of the connection. On the other hand, the contact resistance between the first current collector 24 and the tab 231 is reduced, which contributes to a decrease in the charge / discharge rate of the battery cell 20 and improves the operating performance of the battery cell 20. On the other hand, the occurrence of localized overcurrent between the first current collector 24 and the tab 231 is reduced, which contributes to reducing the risk of temperature rise inside the battery cell 20 and improves the safety of use of the battery cell 20.

[0084] In some embodiments of this application, the area defined by the outer edge of the first current collector 24 is S1, and the area defined by the outer edge of the second current collector 25 is S2, and S1 and S2 satisfy the condition 0.6 ≤ S2 / S1 ≤ 0.9.

[0085] 0.6 ≤ S2 / S1 ≤ 0.9 indicates that, in the thickness direction X of the end cover, the ratio of the area defined by the projection of the second current collector 25 to the area defined by the projection of the first current collector 24 is between 60% and 90%.

[0086] By setting the area ratio of the second current collector 25 to the first current collector 24 to 0.6 to 0.9, on the one hand, the influence of the second current collector 25 on the end cover 22 during assembly due to the excessive area of ​​the second current collector 25 can be reduced, thereby improving the ease of assembly between the end cover 22 and the second current collector 25. On the other hand, the problem of insufficient current conduction area between the first current collector 24 and the second current collector 25 due to the insufficient area of ​​the second current collector 25 can be mitigated.

[0087] In some embodiments of this application, as shown in Figures 4 and 5, the first current collector 24 and the second current collector 25 are both circular in shape, the outer diameter of the first current collector 24 is D1, and the outer diameter of the second current collector 25 is D2, such that D1 > D2.

[0088] Both the first current collector 24 and the second current collector 25 have a disc-shaped structure. Of course, in other embodiments, the first current collector 24 and the second current collector 25 may have other shapes such as elliptical, rectangular, or triangular.

[0089] Making the first current collector 24 and the second current collector 25 circular in shape simplifies manufacturing and reduces the difficulty of assembly.

[0090] In some embodiments of this application, as shown in Figures 3 and 4, the electrode assembly 23 includes a main body 232, with a tab 231 protruding from the end of the main body 232 facing the end cover 22, and the main body 232 is cylindrical. The outer diameter of the main body 232 is D3, satisfying the relationships 0.1 mm ≤ D3 - D1 ≤ 5 mm and 5 mm ≤ D3 - D2 ≤ 10 mm.

[0091] 0.1mm≦D3-D1≦5mm means that the diameter of the first current collector 24 is 0.1mm to 5mm smaller than the diameter of the main body 232, and 5mm≦D3-D2≦10mm means that the diameter of the second current collector 25 is 5mm to 10mm smaller than the diameter of the main body 232.

[0092] Optionally, tabs 231 are installed protruding from each end of the main body 232, and the tabs 231 located at both ends of the main body 232 are connected to the electrode terminals 222 on the end cover 22 and the housing 21, respectively, thereby enabling the input and output of electrical energy from the battery cell 20.

[0093] The tab 231 is flattened at one end of the main body 232 so that it protrudes from one end of the main body 232. The flattened tab 231 has a cylindrical structure and a diameter equal to the diameter of the main body 232.

[0094] By setting the difference between the diameter of the main body 232 of the electrode assembly 23 and the diameter of the first current collector 24 to 0.1 mm to 5 mm, interference between the first current collector 24 and the housing 21 caused by the excessive size of the first current collector 24 can be suppressed, while the insufficient connection area between the first current collector 24 and the tab 231 caused by the undersized first current collector 24 can be mitigated, thereby ensuring a sufficient current conduction area between the first current collector 24 and the tab 231. Similarly, by setting the difference between the diameter of the first current collector 24 and the diameter of the second current collector 25 to 5 mm to 10 mm, interference effects that the second current collector 25 has on the end cover 22 during assembly due to the excessive size of the second current collector 25 can be mitigated, while the insufficient current conduction area between the second current collector 25 and the first current collector 24 caused by the undersized second current collector 25 can be suppressed.

[0095] In some embodiments of this application, refer to Figures 4, 5, and 6, where Figure 6 is a plan view of the first current collector member 24 according to some embodiments of this application. Along the thickness direction X of the end cover, at least one first welding groove 241 is provided on the surface of the first current collector member 24 facing the second current collector member 25, and a first welding region is formed on the first current collector member 24 at the position where the first welding groove 241 is provided, and the first welding region and the tab 231 are welded together.

[0096] A first welding region is formed in the first current collector member 24 at the location where the first welding groove 241 is provided. In other words, the first current collector member 24 is welded to the tab 231 at the location of the first welding groove 241. That is, the bottom wall of the first welding groove 241 is welded to the tab 231, and the bottom wall of the first welding groove 241 is the first welding region.

[0097] The width of the first welding groove 241 is 2 mm to 10 mm, and the depth of the first welding groove 241 is 0.1 mm to 3 mm.

[0098] A first welding groove 241 is provided in the first current collector member 24, and a first welding region is formed at the location of the first welding groove 241 where it is welded to the tab 231. With this structure, on the one hand, the first welding groove 241 plays a positioning role when welding the first current collector member 24 and the tab 231, making welding easier and improving welding accuracy. On the other hand, it contributes to the weld bead penetrating the first current collector member 24 during welding, thus contributing to guaranteeing the quality of the weld.

[0099] In some embodiments of this application, as shown in Figure 6, the area defined by the outer edge of the first current collector 24 is S1, the total area of ​​the first welding region of the first current collector 24 is S3, and S1 and S3 satisfy the condition 0.05 ≤ S3 / S1 ≤ 0.3.

[0100] 0.05 ≤ S3 / S1 ≤ 0.3 indicates that the first welding groove 241 occupies 5% to 30% of the area of ​​the first current collector member 24.

[0101] By setting the ratio of the total area of ​​the first welding region to the area of ​​the first current collector 24 to 0.05 to 0.3, it is possible to suppress the shortage of welding area between the first current collector 24 and the tab 231 caused by the insufficient total area of ​​the first welding region, and on the other hand, it is possible to mitigate the shortage of area in the first current collector 24 for connecting to the second current collector 25, caused by the excessive area occupied by the first welding region in the first current collector 24.

[0102] In some embodiments of this application, as shown in Figure 6, the first welding groove 241 extends along the radial direction of the first current collector member 24.

[0103] The radial direction of the first current collector 24 is in the direction from the center position of the first current collector 24 toward the edge of the first current collector 24, or in the direction from the edge of the first current collector 24 toward the center position of the first current collector 24. In other words, the radial direction of the first current collector 24 passes through the center position of the first current collector 24 and is perpendicular to the thickness direction X of the end cover.

[0104] In some embodiments, both ends of the first welding groove 241 penetrate the outer edge of the first current collector member 24, that is, the first welding groove 241 extends from the center of the first current collector member 24 to the outer edge of the first current collector member 24. Both ends of the first welding groove 241 penetrate the outer edge of the first current collector member 24, thereby ensuring the welding area and welding stability between the first current collector member 24 and the tab 231, and improving the effect of current conduction between the first current collector member 24 and the tab 231.

[0105] If the first welding groove 241 extends along the radial direction of the first current collector member 24, the first welding groove 241 can pass through the center of the first current collector member 24, that is, the first welding area can pass through the center of the first current collector member 24, which contributes to an increase in the welding area between the first current collector member 24 and the tab 231.

[0106] In some embodiments of this application, as shown in Figure 6, a plurality of first welding grooves 241 are provided in the first current collector member 24, the plurality of first welding grooves 241 intersect at an intersection point, the plurality of first welding grooves 241 divide the first current collector member 24 into a plurality of main regions 242, the plurality of main regions 242 are spaced apart around the intersection point, and at least one main region 242 is connected to the second current collector member 25.

[0107] Multiple first welding grooves 241 intersect at an intersection point; that is, multiple first welding grooves 241 are provided on the side of the first current collector member 24 facing the second current collector member 25 in the thickness direction X of the end cover, and the multiple welding grooves intersect at a single intersection point, which is the intersection point. As a result, the portion of the first current collector member 24 facing the second current collector member 25 in the thickness direction X of the end cover is divided into multiple regions, i.e., main regions 242, and the multiple main regions 242 are formed around the intersection point of the multiple first welding grooves 241.

[0108] Exemplary, in Figure 6, there are two first welding grooves 241, and the two welding grooves are perpendicular to each other. Of course, in other embodiments, there may be three, four, or five first welding grooves 241, and the multiple welding grooves may be configured with other angles such as 60 degrees, 70 degrees, or 80 degrees.

[0109] The first current collector member 24 is provided with a plurality of first welding grooves 241, and the plurality of first welding grooves 241 intersect at a single intersection point. With this configuration of the first current collector member 24, on the one hand, the welding area between the first current collector member 24 and the tab 231 can be further increased, and on the other hand, the main region 242 partitioned by the plurality of first welding grooves 241 is connected to the second current collector member 25, contributing to a reduction in the difficulty of connecting the first current collector member 24 and the second current collector member 25.

[0110] In some embodiments of this application, as shown in Figure 6, the intersection point is the center position of the first current collector member 24.

[0111] The intersection point is the center position of the first current collector member 24. In other words, each of the multiple first welding grooves 241 extends along the radial direction of the first current collector member 24, and the multiple first welding grooves 241 intersect at the center position of the first current collector member 24.

[0112] In some embodiments, a first central hole 243 is provided at an intersection, the first central hole 243 penetrates both sides of the first current collector 24 along the thickness direction X of the end cover, and the diameter of the first central hole 243 is equal to the width of the first welding groove 241. By providing a first central hole 243 at the intersection of multiple first welding grooves 241 and making the diameter of the first central hole 243 the same as the width of the first welding groove 241, on the one hand, the electrolyte can be guided to some extent, improving the wetting effect of the electrolyte on the electrode assembly 23, and on the other hand, it can contribute to guiding and discharging gases generated inside the battery cell 20 or smoke generated during welding through the first central hole 243 and the first welding groove 241, thereby improving the operating performance of the battery cell 20.

[0113] Optionally, in Figure 4, a central passage 2321 is provided inside the electrode assembly 23, the central passage 2321 penetrates the electrode assembly 23 along the thickness direction X of the end cover, the central passage 2321 is provided in the main body portion 232 of the electrode assembly 23, and is provided so as to penetrate the tabs 231 located at both ends of the main body portion 232. A second central hole 251 is provided at the center of the second current collector member 25, the second central hole 251 penetrates the second current collector member 25 along the thickness direction X of the end cover, and the central passage 2321, the first central hole 243, and the second central hole 251 are in communication, contributing to the discharge of gas and the entry of electrolyte.

[0114] By arranging multiple first welding grooves 241 to intersect at the center of the first current collector 24, it is possible to ensure that the tabs 231 can be welded to the first current collector 24 at different radial positions of the first current collector 24, thereby improving the welding area and welding stability, and effectively improving the current conduction performance between the tabs 231 and the first current collector 24.

[0115] In some embodiments of this application, as shown in Figure 6, a plurality of flow guide holes 244 are provided in at least one main region 242, and the flow guide holes 244 penetrate both sides of the first current collector member 24 along the thickness direction X of the end cover.

[0116] Multiple flow guide holes 244 are provided in at least one main region 242, that is, at least one region of the first current collector member 24 that is partitioned by the first welding groove 241 is provided with flow guide holes 244.

[0117] Optionally, the area defined by the outer edge of the first current collector 24 is S1, and the total area of ​​the multiple flow guide holes 244 is S4, such that S1 and S4 satisfy 0.2 ≤ S4 / S1 ≤ 0.5. In other words, the multiple flow guide holes 244 occupy 20% to 50% of the area of ​​the first current collector 24.

[0118] By setting the ratio of the total area of ​​the flow guide holes 244 to the area of ​​the first current collector member 24 to 0.2 to 0.5, it is possible to mitigate the poor flow guidance effect to the electrolyte caused by the insufficient total area of ​​the flow guide holes 244, and on the other hand, reduce the risk of insufficient structural strength of the first current collector member 24 and insufficient welding area between the first current collector member 24 and the tab 231, caused by the excessive area of ​​the first current collector member 24 occupied by the flow guide holes 244.

[0119] The diameter of the guide hole 244 is D4, and D4 satisfies the condition 0.1 mm ≤ D4 ≤ 10 mm. By setting the diameter of the guide hole 244 to 0.1 mm to 10 mm, on the one hand, the risk of insufficient structural strength of the first current collector 24 due to an excessively large diameter of the guide hole 244 can be reduced, and on the other hand, the difficulty in electrolyte passage due to an insufficient diameter of the guide hole 244 can be improved.

[0120] In some embodiments, as shown in Figure 6, there are two first welding grooves 241, and the first current collector member 24 is divided into four main regions 242 by the two first welding grooves 241, of which two opposing main regions 242 are connected to the second current collector member 25, and guide holes 244 are provided in the other two opposing main regions 242.

[0121] The first current collector member 24 is provided with two first welding grooves 241, and the two welding grooves divide the first current collector member 24 into four main regions 242, two opposing main regions 242 are connected to the second current collector member 25, and the other two opposing main regions 242 are provided with flow guide holes 244. Such a structure is simple and easy to implement, and can contribute to reducing the difficulty of processing the first current collector member 24 and the difficulty of assembling the battery cell 20.

[0122] Exemplary, the two first welding grooves 241 are perpendicular to each other, and both of the two first welding grooves 241 extend along the radial direction of the first current collector member 24.

[0123] By providing a guide hole 244 in the main region 242 of the first current collector member 24, the electrolyte is allowed to enter the tab 231 along the axial direction of the electrode assembly 23 through the guide hole 244, which contributes to improving the wetting effect of the electrolyte on the electrode assembly 23.

[0124] In some embodiments of this application, refer to Figures 4, 5, and 7, where Figure 7 is a plan view of the second current collector member 25 according to some embodiments of this application. Along the thickness direction X of the end cover, at least one second welding groove 252 is provided on the surface of the second current collector member 25 facing the end cover 22, and a second welding region is formed on the second current collector member 25 at the position where the second welding groove 252 is provided, and the second welding region and the first current collector member 24 are welded together.

[0125] A second welding region is formed in the second current collector member 25 at the location where the second welding groove 252 is provided. In other words, the location of the second current collector member 25 where the second welding groove 252 is located is used for welding to the first current collector member 24. That is, the bottom wall of the second welding groove 252 is welded to the first current collector member 24, and the bottom wall of the second welding groove 252 is the second welding region. The bottom wall of the second welding groove 252 is used to connect to the main region 242 of the first current collector member 24 where the flow guide hole 244 is not provided. This realizes the connection between the second current collector member 25 and the first current collector member 24.

[0126] Exemplary, the second welding groove 252 has an arc-shaped structure, and as shown in Figure 7, there are two second welding grooves 252, which are spaced apart in the circumferential direction around the center position (second central hole 251) of the second current collector member 25, and each end of the second welding groove 252 extends to the outer edge of the second current collector member 25. Of course, in other embodiments, there may be three, four, or five second welding grooves 252 provided on the second current collector member 25.

[0127] Optionally, the second welding groove 252 has a length of 20 mm to 200 mm, a width of 3 mm to 10 mm, and a depth of 0.1 mm to 3 mm.

[0128] A second welding groove 252 is provided in the second current collector member 25, and a second welding region for welding with the first current collector member 24 is formed at the location of the second welding groove 252. With this structure, on the one hand, the second welding groove 252 plays a positioning role when welding the second current collector member 25 and the first current collector member 24, making it easier to weld the second current collector member 25 and the first current collector member 24. On the other hand, it contributes to penetrating the second current collector member 25 during welding, thereby contributing to ensuring the quality of the weld between the second current collector member 25 and the first current collector member 24.

[0129] In some embodiments of this application, refer to Figures 6, 7, and 8, where Figure 8 is a plan view of the second current collector member 25 connected to the first current collector member 24 according to some embodiments of this application. A plurality of first welding grooves 241 are provided on the surface of the first current collector member 24 facing the second current collector member 25 along the thickness direction X of the end cover, and the plurality of first welding grooves 241 intersect at the center of the first current collector member 24, and the plurality of first welding grooves 241 divide the first current collector member 24 into a plurality of main body regions 242. Each second welding region is welded to one main body region 242, and the projection of each second welding groove 252 in the thickness direction X of the end cover is located within the corresponding main body region 242.

[0130] The projection of each second welding groove 252 in the thickness direction X of the end cover is said to be located within the corresponding main region 242, meaning that the region defined by the projection of one second welding groove 252 in the thickness direction X of the end cover is contained within the corresponding main region 242.

[0131] For example, the first current collector member 24 is provided with two first welding grooves 241, which divide the first current collector member 24 into four main regions 242. Similarly, the second current collector member 25 is provided with two second welding grooves 252, which are symmetrical with respect to the center position of the second current collector member 25. As a result, the groove bottom walls (second welding regions) of the two second welding grooves 252 are welded to two opposing main regions 242 out of the four main regions 242.

[0132] In some embodiments, the area defined by the outer edge of the second current collector 25 is S2, and the total area of ​​the second welding region of the second current collector 25 is S5, such that S2 and S5 satisfy 0.05 ≤ S5 / S2 ≤ 0.3. In other words, the second welding groove 252 occupies 5% to 30% of the area of ​​the second current collector 25. By setting the ratio of the total area of ​​the second welding region to the area of ​​the second current collector 25 to 0.3, it is possible to suppress insufficient current conduction caused by insufficient connection area between the second current collector 25 and the first current collector 24, and to mitigate insufficient connection area between the second current collector 25 and the end cover 22 caused by insufficient area occupied by the second welding region.

[0133] The first current collector member 24 is provided with a plurality of first welding grooves 241, and the plurality of welding grooves divide the first current collector member 24 into a plurality of main regions 242, and the main regions 242 are welded to the second welding region formed by the second welding groove 252 of the second current collector member 25, thereby allowing the projection of the second welding groove 252 in the thickness direction X of the end cover to be contained within the corresponding main region 242, and with such a structure, the difficulty of welding the second current collector member 25 and the first current collector member 24 is reduced, and interference between the first welding groove 241 of the first current collector member 24 and the second current collector member 25 when the second current collector member 25 is welded to the first current collector member 24 can be suppressed.

[0134] In some embodiments of this application, embodiments of this application further provide a battery 100, which comprises a housing 10 and a battery cell 20 according to any one of the above-described designs, the battery cell 20 being housed within the housing 10.

[0135] In some embodiments of this application, embodiments of this application further provide an electrical device, the electrical device comprising a battery 100 according to any one of the above-described designs, the battery 100 providing electrical energy to the electrical device.

[0136] An electrical device is any one of the above-mentioned devices or systems that use battery 100.

[0137] In some embodiments of this application, as shown in Figures 3 to 8, the application provides a battery cell 20. The battery cell 20 comprises a housing 21, an end cover 22, an electrode assembly 23, a first current collector member 24, and a second current collector member 25, wherein the first current collector member 24 and the second current collector member 25 are configured separately from each other. The housing 21 has an opening 211, and the end cover 22 is installed so as to cover the opening 211. The electrode assembly 23 is housed within the housing 21 and has a tab 231 at one end of the electrode assembly 23 in the thickness direction X of the end cover. The first current collector member 24 is connected to the tab 231, and the second current collector member 25 is connected to the end cover 22. Along the thickness direction X of the end cover, the first current collector 24 and the second current collector 25 are connected in an overlapping manner, with the second current collector 25 located on the side of the first current collector 24 facing the end cover 22, and the projection of the second current collector 25 located within the outer edge of the first current collector 24. Both the first current collector 24 and the second current collector 25 are circular in shape. The electrode assembly 23 includes a main body 232, with a tab 231 installed so as to protrude from the end of the main body 232 facing the end cover 22, and the main body 232 is cylindrical. The outer diameter of the main body 232 is D3, satisfying the relationships 0.1mm ≤ D3 - D1 ≤ 5mm and 5mm ≤ D3 - D2 ≤ 10mm. Two first welding grooves 241 are provided on the surface of the first current collector member 24 facing the second current collector member 25 along the thickness direction X of the end cover. A first welding region is formed on the first current collector member 24 at the location where the first welding grooves 241 are provided, and the first welding region and the tab 231 are welded together. Both first welding grooves 241 extend along the radial direction of the first current collector member 24 and penetrate the outer edge of the first current collector member 24. The two first welding grooves 241 are perpendicular to each other and intersect at the center of the first current collector member 24, thereby dividing the first current collector member 24 into four main regions 242. Of the four main regions 242, two opposing main regions 242 are connected to the second current collector member 25, and guide holes 244 are provided in the other two opposing main regions 242.

[0138] As long as there is no contradiction, the embodiments and features of the embodiments in this application can be combined with each other.

[0139] The foregoing describes only preferred embodiments of this application and does not limit it. Those skilled in the art may have various modifications and changes to this application. All modifications, equivalent substitutions, improvements, etc., made without departing from the spirit and intent of this application are also included within the scope of protection of this application. [Explanation of Symbols]

[0140] 1000 vehicles 100 batteries 10 cabinets 11. Main body of the first cabinet 12. Second cabinet unit 20 battery cells 21 Housing 211 Aperture 22 End cover 221 Insulating material 222 Electrode terminal 223 Pressure release mechanism 23 Electrode Assembly 231 tabs 232 Main body 2321 Center aisle 24. First current collector 241 First weld groove 242 Subject area 243 1st center hole 244 Direction hole 25. Second current collector 251 2nd center hole 252 Second welding groove 200 Control device 300 engine X End cover thickness direction

Claims

1. It comprises a housing, an end cover, an electrode assembly, a first current collector, and a second current collector. The housing has an opening, The end cover is installed so as to cover the opening, The electrode assembly is housed within the housing and has tabs, The first current collector and the second current collector are configured as separate components, the first current collector is connected to the tab, and the second current collector is connected to the end cover. The first current collector and the second current collector are connected in an overlapping manner along the thickness direction of the end cover, the second current collector is located on the side of the first current collector facing the end cover, and the projection of the second current collector in the thickness direction of the end cover is located within the outer edge of the first current collector. Along the thickness direction of the end cover, at least one first welding groove is provided on the surface of the first current collector member facing the second current collector member, a first welding region is formed on the first current collector member at the position where the first welding groove is provided, and the first welding region is welded to the tab. The first current collector member is provided with a plurality of first welding grooves, the plurality of first welding grooves intersect at an intersection point, the plurality of first welding grooves divide the first current collector member into a plurality of main regions, the plurality of main regions are spaced apart around the intersection point, and at least one of the main regions is connected to the second current collector member. Battery cell.

2. The area defined by the outer edge of the first current collector is S １ The area defined by the outer edge of the second current collector is S ２ S １ and S ２ This means 0.6 ≤ S ２ / S １ Satisfying ≤ 0.9 The battery cell according to claim 1.

3. Both the first current collector and the second current collector are circular in shape. The outer diameter of the first current collector member is D １ and the outer diameter of the second current collector member is D ２ and D １ and D ２ and D １ satisfy D ２ > D The battery cell according to claim 1.

4. The electrode assembly includes a main body, the tab is provided so as to protrude from the end of the main body facing the end cover, and the main body is cylindrical. The outer diameter of the main body is D ３ Therefore, 0.1 mm ≤ D ３ -D １ ≤5mm, 5mm ≤D ３ -D ２ Satisfying ≤ 10 mm The battery cell according to claim 3.

5. The area defined by the outer edge of the first current collector is S １ The total area of ​​the first welding region of the first current collector member is S ３ S １ and S ３ This means that 0.05 ≤ S ３ / S １ Satisfying ≤ 0.3 The battery cell according to claim 1.

6. The first welding groove extends along the radial direction of the first current collector member. The battery cell according to claim 1.

7. Both ends of the first welding groove penetrate the outer edge of the first current collector member. The battery cell according to claim 6.

8. The aforementioned intersection point is the center position of the first current collector member. The battery cell according to claim 1.

9. A first central hole is provided at the aforementioned intersection, the first central hole penetrates both sides of the first current collector member along the thickness direction of the end cover, and the diameter of the first central hole is equal to the width of the first welding groove. The battery cell according to claim 8.

10. A plurality of flow guide holes are provided in at least one of the main regions, and the flow guide holes penetrate both sides of the first current collector member along the thickness direction of the end cover. The battery cell according to claim 1.

11. The area defined by the outer edge of the first current collector is S １ The total area of ​​the multiple flow guide holes is S ４ S １ and S ４ This means that 0.2 ≤ S ４ / S １ Satisfying ≤ 0.5 The battery cell according to claim 10.

12. The diameter of the aforementioned guide hole is D ４ And D ４ 0.1 mm ≤ D ４ Satisfying ≤ 10 mm The battery cell according to claim 10.

13. There are two first welding grooves, and the first current collector is divided into four main regions by the two first welding grooves, of which two opposing main regions are connected to the second current collector, and the other two opposing main regions are provided with the flow guide holes. The battery cell according to claim 10.

14. It comprises a housing, an end cover, an electrode assembly, a first current collector, and a second current collector. The housing has an opening, The end cover is installed so as to cover the opening, The electrode assembly is housed within the housing and has tabs, The first current collector and the second current collector are configured as separate components, the first current collector is connected to the tab, and the second current collector is connected to the end cover. The first current collector and the second current collector are connected in an overlapping manner along the thickness direction of the end cover, the second current collector is located on the side of the first current collector facing the end cover, and the projection of the second current collector in the thickness direction of the end cover is located within the outer edge of the first current collector. Along the thickness direction of the end cover, at least one second welding groove is provided on the surface of the second current collector member facing the end cover, a second welding region is formed on the second current collector member at the position where the second welding groove is provided, and the second welding region and the first current collector member are welded together. A plurality of first welding grooves are provided on the surface of the first current collector member facing the second current collector member along the thickness direction of the end cover, the plurality of first welding grooves intersect at the center position of the first current collector member, and the plurality of first welding grooves divide the first current collector member into a plurality of main regions. Each of the second welding regions is welded to one of the main regions, and the projection of each of the second welding grooves in the thickness direction of the end cover is located within the corresponding main region. Battery cell.

15. The area defined by the outer edge of the second current collector is S ２ The total area of ​​the second welding region of the second current collector member is S ５ S ２ and S ５ This means that 0.05 ≤ S ５ / S ２ Satisfying ≤ 0.3 The battery cell according to claim 14.

16. The casing and Includes a battery cell according to any one of claims 1 to 15, The battery cell is housed within the housing. battery.

17. Includes the battery described in claim 16 Electrical device.

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