Battery cell, battery, and electric device

Abstract

To provide a battery cell, a battery, and an electric device capable of effectively improving use performance and use safety of the 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, the end cover is arranged to cover the opening, the electrode assembly is accommodated in the housing and has a tab, the first current collecting member (24) and the second current collecting member (25) are formed separately from each other, 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 overlapped and connected in a thickness direction of the end cover, the second current collecting member (25) is located on a side of the first current collecting member (24) facing the end cover, and a projection of the second current collecting member (25) is located within an outer edge of the first current collecting member (24).SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority from a Chinese application filed on May 13, 2022, entitled "Battery Cell, Battery and Electrical Device" and bearing application number 202210521640.1, the entire contents of which are incorporated herein by reference.

[0002] This application is in the field of battery technology, and specifically relates to battery cells, batteries, and electrical devices. [Background technology]

[0003] In recent years, new energy vehicles have developed dramatically, and in the field of electric vehicles, power batteries play an important role as the power source for electric vehicles. As new energy vehicles become more popular, demand for power battery products is also increasing. As a core component of new energy vehicles, batteries have high requirements in terms of operational performance and safety in use. A battery cell is obtained by assembling an electrode assembly (bare cell) from a positive electrode plate, a negative electrode plate, and a separator by winding or stacking, placing it in a housing, covering it with an end cover, and injecting an electrolyte. However, batteries based on conventional technology have poor operational performance and relatively significant safety issues during use, making them unsuitable for widespread use and application. Summary of the Invention

[0004] The embodiments of the present application provide a battery cell, a battery, and an electric device that can effectively improve the usage performance and usage safety of the battery.

[0005] In a first aspect, an embodiment of the present application provides a battery cell comprising a housing, an end cover, an electrode assembly, a first current collecting member, and a second current collecting member, the housing having an opening, the end cover being disposed to cover the opening, the electrode assembly being housed in the housing and having a tab, the first current collecting member and the second current collecting member being configured as separate members, the first current collecting member being connected to the tab, and the second current collecting member being connected to the end cover, the first current collecting member and the second current collecting member being connected to overlap each other along a thickness direction of the end cover, the second current collecting member being located on a side of the first current collecting member facing the end cover, and a projection of the second current collecting member being located within an outer edge of the first current collecting member.

[0006] In the above technical solution, the first current collecting member and the second current collecting member 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, thereby connecting the first current collecting member to the tab of the electrode assembly and connecting the second current collecting member to the end cover, and then achieving an electrical connection between the electrode assembly and the end cover. The projection of the second current collecting member in the thickness direction of the end cover is located within the outer edge of the first current collecting member, i.e., the area of ​​the first current collecting member is larger than the area of ​​the second current collecting member. As a result, it is only necessary to assemble the second current collecting member and the end cover during the process of assembling the battery cell. In this way, the area of ​​the first current collecting member is not limited by the end cover, which contributes to reducing the difficulty of connecting the first current collecting member and the tab, and contributes to increasing the connection area and improving the connection stability between the first current collecting member and the tab. On the one hand, the contact resistance between the first current collecting member and the tab is reduced, which contributes to reducing the charge / discharge rate of the battery cell and improving the usage performance of the battery cell. On the other hand, it reduces the occurrence of local overcurrent between the first current collecting member and the tab, which contributes to reducing the risk of temperature rise inside the battery cell and improving the usage safety of the battery cell.

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

[0008] In the above technical proposal, if the area ratio between the second current collecting member and the first current collecting member is set to 0.6 to 0.9, on the one hand, the influence that the second current collecting member has on the end cover during assembly due to an excessively large area of ​​the second current collecting member can be reduced, thereby improving the ease of assembly between the end cover and the second current collecting member, and on the other hand, it can mitigate the situation where the current conduction area between the first current collecting member and the second current collecting member becomes too small due to an excessively small area of ​​the second current collecting member.

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

[0010] In the above technical proposal, if the first current collecting member and the second current collecting member are each circular, manufacturing is easy and this contributes to reducing the difficulty of assembly.

[0011] In some embodiments, the electrode assembly includes a main body, the tab protruding from an end of the main body facing the end cover, the main body being cylindrical, and the main body having an outer diameter D3, satisfying 0.1 mm≦D3−D1≦5 mm and 5 mm≦D3−D2≦10 mm.

[0012] In the above technical proposal, if the difference between the diameter of the main body of the electrode assembly and the diameter of the first current collecting member is 0.1 mm to 5 mm, on the one hand, interference between the first current collecting member and the housing caused by an excessively large first current collecting member can be suppressed, and on the other hand, a lack of connection area between the first current collecting member and the tab caused by an undersized first current collecting member can be alleviated, thereby ensuring the current conduction area between the first current collecting member and the tab. Similarly, if the difference between the diameter of the main body and the diameter of the second current collecting member is 5 mm to 10 mm, on the one hand, interference between the second current collecting member and the end cover during assembly caused by an excessively large second current collecting member can be alleviated, and on the other hand, a lack of current conduction area between the second current collecting member and the first current collecting member caused by an undersized second current collecting member can be alleviated.

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

[0014] In the above technical solution, a first welding groove is provided on the first current collecting member, and a first welding area to be welded to the tab is formed at the location of the first welding groove. With this structure, on the one hand, the first welding groove plays a positioning role when welding the first current collecting member to the tab, making welding easier and improving welding accuracy; on the other hand, it contributes to penetrating the first current collecting member during welding, contributing to ensuring welding quality.

[0015] In some embodiments, an area defined by an outer edge of the first current collecting member is S1, a total area of ​​the first welding region of the first current collecting member is S3, and S1 and S3 satisfy 0.05≦S3 / S1≦0.3.

[0016] In the above technical proposal, if the ratio of the total area of ​​the first welding region to the area of ​​the first current collecting member is set to 0.05 to 0.3, on the one hand, it is possible to suppress a shortage of the welding area between the first current collecting member and the tab caused by an insufficient total area of ​​the first welding region, and on the other hand, it is possible to alleviate a shortage of the area in the first current collecting member for connecting to the second current collecting member caused by an excessively large area occupied by the first welding region in the first current collecting member.

[0017] In some embodiments, the first weld groove extends along a radial direction of the first current collecting member.

[0018] In the above technical proposal, if the first welding groove extends along the radial direction of the first current collecting member, the first welding groove can pass through the center position of the first current collecting member, that is, the first welding area can pass through the center position of the first current collecting member, which contributes to increasing the welding area between the first current collecting member and the tab.

[0019] In some embodiments, both ends of the first weld groove penetrate the outer edge of the first current collecting member.

[0020] In the above technical solution, both ends of the first welding groove penetrate the outer edge of the first current collecting member, so that the first welding area formed by the first welding groove extends from the center position of the first current collecting member to the outer edge of the first current collecting member, which ensures the welding area and welding stability between the first current collecting member and the tab, and improves the effectiveness of current conduction between the first current collecting member and the tab.

[0021] In some embodiments, the first current collecting member has a plurality of first weld grooves, the plurality of first weld grooves intersecting at an intersection location, the plurality of first weld grooves dividing the first current collecting member into a plurality of main body regions, the plurality of main body regions being spaced apart around the intersection location, and at least one of the main body regions being connected to the second current collecting member.

[0022] In the above technical proposal, a plurality of first welding grooves are provided on the first current collecting member, and the plurality of first welding grooves intersect at one intersection position. With a first current collecting member of 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 area partitioned by the plurality of first welding grooves is connected to the second current collecting member, contributing to reducing the difficulty of connecting the first current collecting member and the second current collecting member.

[0023] In some embodiments, the intersection point is a center point of the first current collecting member.

[0024] In the above technical solution, if the multiple first welding grooves intersect at the center position of the first current collecting member, it is possible to ensure that the tab can be welded to the first current collecting member even at different radial positions of the first current collecting member, thereby 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, 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, a first central hole is provided at the intersection of multiple first welding grooves, and the diameter of the first central hole is the same as the width of the first welding grooves. This, on the one hand, can guide the electrolyte to a certain extent and improve the wetting effect of the electrolyte on the electrode assembly, and, on the other hand, can help guide and exhaust gas generated inside the battery cell or smoke generated during welding through the first central hole and the first welding grooves, thereby improving the usability of the battery cell.

[0027] In some embodiments, at least one of the main body regions is provided with a plurality of flow guide holes, which penetrate both sides of the first current collecting member along the thickness direction of the end cover.

[0028] In the above technical proposal, by providing a flow guide hole in the main region of the first current collecting member, the electrolyte is allowed to enter the tab along the axial direction of the electrode assembly through the flow guide hole, which contributes to improving 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 collecting member is S1, the total area of ​​the plurality of flow guide holes is S4, and S1 and S4 satisfy 0.2≦S4 / S1≦0.5.

[0030] In the above technical proposal, if the ratio of the total area of ​​the flow guide holes to the area of ​​the first current collecting member is set to 0.2 to 0.5, on the one hand, it is possible to alleviate poor electrolyte flow guidance effect caused by an insufficient total area of ​​the flow guide holes, and on the other hand, it is possible to reduce the risk of insufficient structural strength of the first current collecting member and insufficient welding area between the first current collecting member and the tab caused by an excessively large area of ​​the first current collecting member occupied by the flow guide holes.

[0031] In some embodiments, the diameter of the guide hole is D4, and D4 satisfies 0.1 mm≦D4≦10 mm.

[0032] In the above technical proposal, if the diameter of the flow guide holes is set to 0.1 mm to 10 mm, on the one hand, it is possible to reduce the risk of insufficient structural strength of the first current collecting member caused by an excessively large diameter of the flow guide holes, and on the other hand, it is possible to improve the situation in which it is difficult for the electrolyte to pass through caused by an excessively small diameter of the flow guide holes.

[0033] In some embodiments, there are two first weld grooves, and the two first weld grooves divide the first current collecting member into four main regions, and of the four main regions, two opposing main regions are connected to the second current collecting member, and the flow guide holes are provided in the other two opposing main regions.

[0034] In the above technical proposal, two first welding grooves are provided on the first current collecting member, and the two welding grooves divide the first current collecting member into four main regions, two opposing main regions are connected to the second current collecting member, and the other two opposing main regions are provided with flow guide holes.This structure is simple and can be easily implemented, and can contribute to reducing the difficulty of processing the first current collecting 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 collecting member facing the end cover along the thickness direction of the end cover, and a second welding area is formed on the second current collecting member at the position where the second welding groove is provided, and the second welding area and the first current collecting member are welded together.

[0036] In the above technical proposal, a second welding groove is provided in the second current collecting member, and a second welding area to be welded to the first current collecting 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 collecting member to the first current collecting member, making it easier to weld the second current collecting member to the first current collecting member; on the other hand, it contributes to penetrating the second current collecting member during welding, and contributes to ensuring the quality of the welding between the second current collecting member and the first current collecting member.

[0037] In some embodiments, a plurality of first welding grooves are provided on the surface of the first current collecting member facing the second current collecting member along the thickness direction of the end cover, the plurality of first welding grooves intersect at the center position of the first current collecting member, the plurality of first welding grooves divide the first current collecting member into a plurality of main body regions, each of the second welding regions is welded to one of the main body 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 body region.

[0038] In the above technical proposal, a plurality of first welding grooves are provided on the first current collecting member, and the plurality of welding grooves divide the first current collecting member into a plurality of main regions, which are welded to second welding regions formed by second welding grooves in the second current collecting member, thereby allowing the projection of the second welding grooves in the thickness direction of the end cover to be contained within the corresponding main region.This structure contributes to reducing the difficulty of welding the second current collecting member and the first current collecting member, and can suppress interference with the first welding grooves of the first current collecting member when the second current collecting member is welded to the first current collecting member.

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

[0040] In the above technical proposal, if the ratio of the total area of ​​the second welding region to the area of ​​the second current collecting member is set to 0.05 to 0.3, on the one hand, it is possible to suppress insufficient current conduction caused by an insufficient connection area between the second current collecting member and the first current collecting member, and on the other hand, it is possible to alleviate insufficient connection area between the second current collecting member and the end cover caused by an excessively large area occupied by the second welding region.

[0041] In a second aspect, an embodiment of the present application further provides a battery, the battery including a housing and the above-described battery cell, the battery cell being housed in the housing.

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

[0043] In order to more clearly explain the technical solutions of the embodiments of the present application, the drawings used in the embodiments will be briefly described below. The drawings described are only for illustrating some embodiments of the present application and are not intended to limit the scope. Those skilled in the art can obtain other related drawings based on these drawings without using inventive abilities. [Brief explanation of the drawings]

[0044] [Figure 1] 1 is a schematic diagram of a vehicle according to some embodiments of the present application. [Figure 2] 1 is an exploded view illustrating the construction of a battery according to some embodiments of the present application. [Figure 3] FIG. 1 is an exploded view illustrating the configuration of a battery cell according to some embodiments of the present application. [Figure 4] 1 is a partial cross-sectional view of a battery cell according to some embodiments of the present application. [Figure 5] 1A and 1B are schematic diagrams illustrating connections between a first current collecting member and a second current collecting member according to some embodiments of the present application. [Figure 6] FIG. 2 is a plan view of a first current collecting member according to some embodiments of the present application. [Figure 7] FIG. 2 is a plan view of a second current collecting member according to some embodiments of the present application. [Figure 8] FIG. 2 is a plan view of a second current collecting member connected to a first current collecting member according to some embodiments of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0045] In order to make the objectives, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly explained below with reference to the drawings used in the embodiments of the present application. The described embodiments are only some of the embodiments of the present application, and are not all of the embodiments. Based on the embodiments of the present application, all embodiments obtained by those skilled in the art without using inventive ability also fall within the scope of protection of the present application.

[0046] Unless otherwise specified, all technical and scientific terms used in this application have the meanings commonly understood by those skilled in the art. The terms used in this application are merely for the purpose of describing specific embodiments and are not intended to limit the present application. The terms "comprise," "have," and any variations thereof in the specification, claims, and above description of the drawings of this application mean a non-exclusive inclusion. The terms "first," "second," and the like in the specification, claims, and above description of the drawings of this application are merely intended to distinguish between different elements and do not stipulate a particular order or primary and secondary elements.

[0047] When the term "embodiment" is used in this application, it means that a particular feature, configuration, or characteristic described using the embodiment is included in at least one embodiment of this application. The use of this term in various parts of the specification does not necessarily refer to the same embodiment, nor is it intended to limit independent or alternative embodiments that are mutually exclusive from other embodiments.

[0048] In the description of this application, unless otherwise specified, the terms "attach," "couple," "connect," and "attach" should be understood in a broad sense. For example, they may refer to a fixed connection, a detachable connection, or an integral connection. They may be directly connected, indirectly connected via an intermediate object, or the interiors of two elements may be in communication with each other. Those skilled in the art will be able to understand the specific meanings of the above terms in this application depending on the specific circumstances.

[0049] The term "and / or" used in this application is merely for explaining the relationship between related objects and represents three types of relationships, for example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the symbol " / " in this application generally represents the relationship indicated by "or" between the related objects before and after it.

[0050] In the embodiments of the present application, like reference numerals refer to like parts, and for the sake of simplicity, detailed descriptions of like parts in different embodiments will be omitted. The dimensions such as thickness and length of various parts in the embodiments of the present application shown in the drawings, and the dimensions such as thickness and length of the entire integrated device, are for illustrative purposes only and do not limit the present application.

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

[0052] In this application, the battery cell includes a lithium ion secondary battery, a lithium ion primary battery, a lithium-sulfur battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery, but is not limited to these in the examples of this application. The battery cell may be cylindrical, flat, rectangular, or have other shapes, but is not limited to these in the examples of this application. Battery cells are generally divided into three types based on packaging methods: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, but is not limited to these in the examples of this application.

[0053] The battery described in the examples of this application refers to a single physical module containing one or more battery cells to provide higher voltage and capacity. For example, the battery described in this application includes a battery module or a battery pack. The battery generally includes a housing for packaging one or more battery cells or multiple battery modules. The housing can prevent liquids or other foreign objects from affecting the charging and discharging of the battery cells.

[0054] A battery cell includes a housing, an electrode assembly, and an electrolyte, with the housing configured to accommodate the electrode assembly and the electrolyte. The electrode assembly is composed 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 electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode current collector and a positive electrode active material layer. The positive electrode active material layer is applied to the surface of the positive electrode current collector, and the portion of the positive electrode current collector where the positive electrode active material layer is not applied serves as a positive electrode tab, which realizes the input and output of electrical energy to and from the positive electrode plate. For example, in a lithium-ion battery, the positive electrode current collector is made of 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 portion of the negative electrode current collector where the negative electrode active material layer is not coated serves as a negative electrode tab, which realizes the input and output of electrical energy to the negative electrode plate. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon-based or silicon-based, etc. To ensure that they do not melt when a large current flows, the positive electrode tab is stacked in multiple layers, and the negative electrode tab is stacked in multiple layers.

[0055] The separator may be made of PP (polypropylene), PE (polyethylene), etc. The electrode assembly may have a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

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

[0057] As the inventors have discovered, in a typical battery cell, the electrode assembly is electrically connected to the end cover by connecting the tab of the electrode assembly to the end cover, thereby making the end cover the positive or negative output terminal of the battery cell. To facilitate the electrical connection between the tab of the electrode assembly and the end cover, current collector plates are typically installed within the housing, and the current collector plates are connected to the end cover and the tab of the electrode assembly (the tabs are full tabs that are flattened and connected to the current collector plate), thereby achieving electrical connection between the electrode assembly and the end cover. The greater the feed amount required to flatten the tab (i.e., the greater the amount of flattening and pressing of the tab), the larger the tab area. However, the greater the feed amount required to flatten the tab, the greater the difficulty of welding the tab to the current collector plate and the stability of the weld between the tab and the current collector plate. In the prior art, to ensure the effectiveness of the electrical connection between the electrode assembly and the end cover, a disk sleeve is attached to the outer periphery of the current collector plate, which on the one hand protects the current collector plate and on the other hand increases the diameter of the current collector plate to ensure that welding can be performed up to the outermost tab during welding. The increased diameter also allows the welding area to be further extended toward the edge of the winding core, thereby reducing the internal resistance of the battery cell. However, because the current collector plate in this structure is affected by the end cover, the area of ​​the current collector plate is relatively small, and the difficulty of welding the current collector plate to the tab is still relatively high. Poor welding is likely to occur between the current collector plate and the tab of the electrode assembly, which is detrimental to improving the stability of the connection between the current collector plate and the tab. As a result, on the one hand, the contact resistance between the current collector plate and the tab of the electrode assembly is still relatively high, and the charge / discharge rate of the battery cell is relatively high, which is detrimental to improving the usage performance of the battery cell. On the other hand, local overcurrent is likely to occur between the current collector plate and the tab of the electrode assembly during use, which increases the risk of temperature rise inside the battery cell, which is detrimental to improving the usage safety of the battery cell.

[0058] In light of the above, and to solve the problem of relatively low performance and safety in use of battery cells, the inventors conducted extensive research and designed a battery cell including a housing, an end cover, an electrode assembly, a first current collecting member, and a second current collecting member. The housing has an opening, and the end cover is installed to cover the opening. The electrode assembly is housed within the housing and has a tab. The first current collecting member and the second current collecting member are configured separately from each other, the first current collecting member is connected to the tab, and the second current collecting member is connected to the end cover. The first current collecting member and the second current collecting member are connected to overlap each other along the thickness direction of the end cover, the second current collecting member is located on the side of the first current collecting member facing the end cover, and the projection of the second current collecting member is located within the outer edge of the first current collecting member.

[0059] In the above-mentioned battery cell, the first current collecting member and the second current collecting member 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, thereby realizing an electrical connection between the electrode assembly and the end cover after the first current collecting member and the tab of the electrode assembly are connected and the second current collecting member and the end cover are connected. The projection of the second current collecting member in the thickness direction of the end cover is located within the outer edge of the first current collecting member, i.e., the area of ​​the first current collecting member is larger than the area of ​​the second current collecting member. As a result, it is only necessary to assemble the second current collecting member and the end cover during the process of assembling the battery cell. In this way, the area of ​​the first current collecting member is not limited by the end cover, which contributes to reducing the difficulty of connecting the first current collecting member and the tab, and contributes to increasing the connection area and improving the connection stability between the first current collecting member and the tab. On the one hand, the contact resistance between the first current collecting member and the tab is reduced, which contributes to reducing the charge / discharge rate of the battery cell and improving the usage performance of the battery cell. On the other hand, it reduces the occurrence of local overcurrent between the first current collecting member and the tab, which contributes to reducing the risk of temperature rise inside the battery cell and improving the usage safety of the battery cell.

[0060] The battery cells according to the embodiments of the present application can be used in, but are not limited to, electric devices such as vehicles, ships, and aircraft. The battery cells and batteries according to the present application can be used to configure the power supply system of the electric device, thereby effectively improving the stability and reliability of the connection between the current collecting member and the electrode assembly, thereby improving the performance and safety of the battery cells.

[0061] An embodiment of the present application provides a battery-powered electric device. The electric device includes, but is not limited to, a mobile phone, a tablet, a laptop, an electric toy, an electric tool, an electric car, an electric vehicle, a boat, an aircraft, etc. The electric toy includes a stationary or mobile device, such as a game console, an electric car toy, an electric boat toy, and an electric plane toy. The aircraft includes an airplane, a rocket, a space shuttle, and a spaceship, etc.

[0062] For convenience of explanation, in the following embodiment, a vehicle 1000 is used as an example to describe an electrical device according to an embodiment of the present application.

[0063] FIG. 1 is a schematic diagram of a vehicle 1000 according to some embodiments of the present application. The vehicle 1000 may be a fuel-powered vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle may be an electric vehicle, a hybrid vehicle, or a range-extended electric vehicle. A battery 100 is disposed inside the vehicle 1000, and the battery 100 is disposed 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 steering the vehicle 1000. The vehicle 1000 further includes a control device 200 and an engine 300, and the control device 200 controls the power supply from the battery 100 to the engine 300, for example, to supply electricity for starting the vehicle 1000, navigation, and operation during driving.

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

[0065] 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, which are housed within the housing 10. The housing 10 provides an assembly space for the battery cells 20 and may have a variety of configurations. In some embodiments, the housing 10 includes a first housing body 11 and a second housing body 12, which, when combined with each other, define an assembly space for housing the battery cells 20. The second housing body 12 may have a hollow structure with one end open, and the first housing body 11 may have a plate-like structure and be installed so as to cover the open side of the second housing body 12, with the first housing body 11 and the second housing body 12 defining an assembly space, or the first housing body 11 and the second housing body 12 may both have a hollow structure with one end 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 may have various shapes, such as a cylindrical body or a rectangular parallelepiped.

[0066] The battery 100 may include a plurality of battery cells 20, and the plurality of battery cells 20 may be connected in series, in parallel, or in a manner including both. The term "connected in a manner including both" refers to the case where some of the plurality of battery cells 20 are connected in series and some are connected in parallel. The plurality of battery cells 20 may be directly connected in series or in parallel, or in a manner including both, and the integrated battery cells 20 may be housed within the case 10. The battery 100 may be formed by first connecting the plurality of battery cells 20 in series or in parallel, or in a manner including both, to form a battery module, and then connecting the plurality of battery modules in series or in parallel, or in a manner including both, to form an integrated battery module, and then housed within the case 10. The battery 100 may further include other structures, for example, the battery 100 may further include busbar members for electrically connecting the plurality of battery cells 20 together.

[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 cells 20 may be cylindrical, flat, rectangular, or have other shapes. Illustratively, as shown in FIG. 2, the battery cells 20 are cylindrical.

[0068] In some embodiments of the present application, reference is made to FIGS. 3 , 4 , and 5 . FIG. 3 is an exploded view illustrating a configuration of a battery cell 20 according to some embodiments of the present application. FIG. 4 is an exploded view illustrating a configuration of a current collecting member according to some embodiments of the present application. FIG. 5 is a schematic diagram illustrating a connection between a first current collecting member 24 and a second current collecting member 25 according to some embodiments of the present application. The present application provides a battery cell 20 including a housing 21, an end cover 22, an electrode assembly 23, the first current collecting member 24, and the second current collecting member 25. The housing 21 has an opening 211, and the end cover 22 is disposed to cover the opening 211. The electrode assembly 23 is housed in the housing 21 and has a tab 231. The first current collecting member 24 and the second current collecting member 25 are configured separately from each other. The first current collecting member 24 is connected to the tab 231, and the second current collecting member 25 is connected to the end cover 22. The first current collecting member 24 and the second current collecting member 25 are overlapping and connected along the thickness direction X 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 22, and the projection of the second current collecting member 25 is located within the outer edge of the first current collecting member 24.

[0069] The first current collecting member 24 and the second current collecting member 25 are connected in an overlapping manner along the thickness direction X of the end cover, and the second current collecting member 25 is located on the side of the first current collecting member 24 facing the end cover 22; in other words, the first current collecting member 24 and the second current collecting member 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 collecting member 24 is farther from the end cover 22 than the second current collecting member 25.

[0070] The projection of the second current collecting member 25 being located within the outer edge of the first current collecting member 24 means that the projection of the second current collecting member 25 is located within the area defined by the outer edge of the first current collecting member 24 along the thickness direction X of the end cover, that is, the area of ​​the second current collecting member 25 is smaller than that of the first current collecting member 24.

[0071] Optionally, the connection between the first current collecting member 24 and the tab 231, the connection between the first current collecting member 24 and the second current collecting member 25, and the connection between the second current collecting member 25 and the end cover 22 may be by abutment or welding. Exemplarily, in this embodiment, the first current collecting member 24 and the tab 231 are welded, the first current collecting member 24 and the second current collecting member 25 are welded, and the second current collecting member 25 and the end cover 22 are welded.

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

[0073] Optionally, the housing 21 also contains an electrolyte, for example, an electrolyte solution. The housing 21 can be constructed in a variety of ways. The housing 21 can be made of a variety of materials, such as copper, iron, aluminum, steel, aluminum alloys, etc.

[0074] When assembling the battery cell 20, the electrode assembly 23 is first placed in the housing 21, the housing 21 is filled with electrolyte, and the end cover 22 is then placed to cover the opening 211 of the housing 21 to form a sealed connection, forming a sealed space that contains the electrode assembly 23 and the electrolyte. For example, the end cover 22 is welded to the housing 21.

[0075] An insulating member 221 is installed on the end cover 22, and 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 periphery of the second current collecting member 25, thereby providing insulation protection for the second current collecting member 25 and serving as a positioning element during installation. For example, the insulating member 221 can be made of various materials such as rubber, plastic, or silicone rubber.

[0076] The housing 21 may have various shapes, such as a cylinder or a rectangle. 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 structure, the housing 21 will have a rectangular structure. For example, in FIG. 3, the electrode assembly 23 has a cylindrical structure, so the housing 21 is cylindrical.

[0077] 3 , the housing 21 has a hollow structure with one end open, and the end cover 22 is installed to cover the opening 211 of the housing 21, forming a hermetically sealed connection, thereby forming a hermetically sealed space that contains 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 flows between the electrode terminals 222 and the end cover 22. The electrode assembly 23 has tabs 231 (positive and negative electrode tabs) on 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 remote from the end cover 22, respectively, to form the positive and negative output electrodes of the battery cell 20. Of course, the tab 231 and the electrode terminal 222 or the housing 21 may be directly connected by welding or abutting, or the tab 231 may be connected via another component, for example, by welding or abutting to another component and then connecting to the electrode terminal 222 or the housing 21.

[0078] Along the thickness direction X of the end cover, a tab 231 on the end of the electrode assembly 23 facing the end cover 22 is connected to the first current collecting member 24, and a second current collecting member 25 is connected to an electrode terminal 222 of the end cover 22. The second current collecting member 25 is directly connected to the electrode terminal 222 of the end cover 22; for example, the second current collecting member 25 is directly welded or abutted to the electrode terminal 222, thereby achieving electrical connection between the second current collecting member 25 and the electrode terminal 222. Of course, the second current collecting member 25 may also be indirectly connected to the electrode terminal 222 of the end cover 22; for example, the second current collecting member 25 is welded or abutted to an intermediate member, and then the intermediate member is welded or abutted 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 has a hollow structure with both ends open, and each end cover 22 is installed to cover one opening 211 of the housing 21 to form a sealed connection, thereby forming a sealed space for accommodating the electrode assembly 23 and electrolyte. In an embodiment in which the housing 21 has a hollow structure with both ends open, electrode terminals 222 are installed 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 form the positive and negative output electrodes of the battery cell 20. Furthermore, in a battery cell 20 having this configuration, the first current collecting member 24 and the second current collecting member 25 may be installed only between one end cover 22 and the electrode assembly 23, or the first current collecting member 24 and the second current collecting member 25 may be installed between each end cover 22 and the electrode assembly 23, and the embodiments of the present application are not limited to this.

[0080] The electrode assembly 23 is a component in which an electrochemical reaction occurs in the battery cell 20. The electrode assembly 23 includes a positive electrode plate, a negative electrode plate, and a separator. The electrode assembly 23 may have a wound structure formed by winding a positive electrode plate, a separator, and a negative electrode plate, or may have a stacked structure formed by stacking a positive electrode plate, a separator, and a negative electrode plate. For example, in FIG. 3, the electrode assembly 23 has a wound structure formed by winding a positive electrode plate, a separator, and a negative electrode plate.

[0081] 3 , the battery cell 20 further includes a pressure release mechanism 223, which may be attached to the end cover 22 or the housing 21. The pressure release mechanism 223 is configured to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

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

[0083] The first current collecting member 24 and the second current collecting member 25 are placed 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, thereby connecting the first current collecting member 24 to the tab 231 of the electrode assembly 23 and connecting the second current collecting member 25 to the end cover 22, and then achieving electrical connection between the electrode assembly 23 and the end cover 22. The projection of the second current collecting member 25 in the thickness direction X of the end cover is located within the outer edge of the first current collecting member 24, i.e., the area of ​​the first current collecting member 24 is larger than the area of ​​the second current collecting member 25. As a result, when assembling the battery cell 20, it is sufficient to assemble the second current collecting member 25 and the end cover 22. In this way, the area of ​​the first current collecting member 24 is not limited by the end cover 22, which contributes to reducing the difficulty of connecting the first current collecting member 24 and the tab 231, and contributing to increasing the connection area and improving the connection stability between the first current collecting member 24 and the tab 231. On the one hand, the contact resistance between the first current collecting member 24 and the tab 231 is reduced, which contributes to reducing the charge / discharge rate of the battery cell 20 and improving the usage performance of the battery cell 20. On the other hand, it reduces the occurrence of local overcurrent between the first current collecting member 24 and the tab 231, which contributes to reducing the risk of an increase in temperature inside the battery cell 20 and improving the usage safety of the battery cell 20.

[0084] In some embodiments of the present application, the area defined by the outer edge of the first current collecting member 24 is S1, the area defined by the outer edge of the second current collecting member 25 is S2, and S1 and S2 satisfy 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 of ​​the region defined by the projection of the second current collecting member 25 to the area of ​​the region defined by the projection of the first current collecting member 24 is 60% to 90%.

[0086] If the area ratio between the second current collecting member 25 and the first current collecting member 24 is set to 0.6 to 0.9, on the one hand, the influence that the second current collecting member 25 has on the end cover 22 during assembly due to the area of ​​the second current collecting member 25 being excessively large can be reduced, thereby improving the ease of assembling the end cover 22 and the second current collecting member 25, and on the other hand, the insufficient current conduction area between the first current collecting member 24 and the second current collecting member 25 due to the area of ​​the second current collecting member 25 being excessively small can be alleviated.

[0087] In some embodiments of the present application, as shown in Figures 4 and 5, the first current collecting member 24 and the second current collecting member 25 are both circular, the outer diameter of the first current collecting member 24 is D1, the outer diameter of the second current collecting member 25 is D2, and D1 and D2 satisfy D1 > D2.

[0088] The first current collecting member 24 and the second current collecting member 25 are both disk-shaped structures. Of course, in other embodiments, the first current collecting member 24 and the second current collecting member 25 may have other shapes, such as an oval, a rectangle, or a triangle.

[0089] If the first current collecting member 24 and the second current collecting member 25 are each made circular, they can be easily manufactured, which contributes to reducing the difficulty of assembly.

[0090] 3 and 4, the electrode assembly 23 includes a main body 232, a tab 231 is provided 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 main body 232 has an outer diameter D3, which satisfies 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 collecting member 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 collecting member 25 is 5mm to 10mm smaller than the diameter of the main body 232.

[0092] Optionally, tabs 231 are protruding from both ends 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, to realize the input and output of electrical energy to the battery cell 20.

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

[0094] Setting the difference between the diameter of the main body 232 of the electrode assembly 23 and the diameter of the first current collecting member 24 to 0.1 mm to 5 mm, on the one hand, suppresses interference between the first current collecting member 24 and the housing 21 caused by the first current collecting member 24 being too large, and on the other hand, mitigates a lack of connection area between the first current collecting member 24 and the tab 231 caused by the first current collecting member 24 being too small, thereby ensuring the current conduction area between the first current collecting member 24 and the tab 231. Similarly, setting the difference between the diameter of the first current collecting member 24 and the diameter of the second current collecting member 25 to 5 mm to 10 mm, on the other hand, mitigates the influence of interference between the second current collecting member 25 and the end cover 22 during assembly caused by the second current collecting member 25 being too large, and on the other hand, prevents a lack of current conduction area between the second current collecting member 25 and the first current collecting member 24 caused by the second current collecting member 25 being too small.

[0095] 4, 5, and 6, which are plan views of the first current collecting member 24 according to some embodiments of the present application. At least one first welding groove 241 is provided on the surface of the first current collecting member 24 facing the second current collecting member 25 along the thickness direction X of the end cover, and a first welding area is formed on the first current collecting member 24 at the position where the first welding groove 241 is provided, and the first welding area and the tab 231 are welded together.

[0096] A first welding area is formed at the position of the first current collecting member 24 where the first welding groove 241 is provided, that is, the first current collecting 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 area.

[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 collecting member 24, and a first welding area to be welded to the tab 231 is formed at the location of the first welding groove 241.With this structure, on the one hand, the first welding groove 241 plays a positioning role when welding the first current collecting member 24 and the tab 231, making welding easier and improving welding accuracy, and on the other hand, it contributes to the penetration of the weld bead through the first current collecting member 24 during welding, contributing to ensuring the quality of the welding.

[0099] In some embodiments of the present application, as shown in FIG. 6 , the area defined by the outer edge of the first current collecting member 24 is S1, the total area of ​​the first welding region of the first current collecting member 24 is S3, and S1 and S3 satisfy 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 collecting member 24.

[0101] By setting the ratio of the total area of ​​the first welding region to the area of ​​the first current collecting member 24 to 0.05 to 0.3, it is possible to suppress the insufficiency of the welding area between the first current collecting member 24 and the tab 231 caused by the total area of ​​the first welding region being too small, and on the other hand, it is possible to alleviate the insufficiency of the area in the first current collecting member 24 for connecting to the second current collecting member 25 caused by the area occupied by the first welding region being too large in the first current collecting member 24.

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

[0103] The radial direction of the first current collecting member 24 is the direction from the center position of the first current collecting member 24 toward the edge of the first current collecting member 24, or the direction from the edge of the first current collecting member 24 toward the center position of the first current collecting member 24. In other words, the radial direction of the first current collecting member 24 passes through the center position of the first current collecting member 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 collecting member 24, that is, the first welding groove 241 extends from the center of the first current collecting member 24 to the outer edge of the first current collecting member 24. Because both ends of the first welding groove 241 penetrate the outer edge of the first current collecting member 24, the first welding area formed by the first welding groove 241 extends from the center of the first current collecting member 24 to the outer edge of the first current collecting member 24, which ensures the welding area and welding stability between the first current collecting member 24 and the tab 231 and improves the current conduction effect between the first current collecting member 24 and the tab 231.

[0105] If the first welding groove 241 is made to extend radially along the first current collecting member 24, the first welding groove 241 can pass through the center position of the first current collecting member 24, that is, the first welding area can pass through the center position of the first current collecting member 24, which contributes to increasing the welding area between the first current collecting member 24 and the tab 231.

[0106] In some embodiments of the present application, as shown in FIG. 6 , a plurality of first welding grooves 241 are provided in the first current collecting member 24, the plurality of first welding grooves 241 intersect at an intersection position, the plurality of first welding grooves 241 divide the first current collecting member 24 into a plurality of main regions 242, the plurality of main regions 242 are configured at intervals around the intersection position, and at least one main region 242 is connected to the second current collecting member 25.

[0107] The multiple first welding grooves 241 intersect at an intersection position, i.e., the multiple first welding grooves 241 are provided on the side of the first current collecting member 24 facing the second current collecting member 25 in the thickness direction X of the end cover, and the multiple welding grooves intersect at one intersection point, which is the intersection position.As a result, the portion of the first current collecting member 24 facing the second current collecting 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 position of the multiple first welding grooves 241.

[0108] 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 included angles, such as 60 degrees, 70 degrees, or 80 degrees.

[0109] A first current collecting member 24 has a plurality of first welding grooves 241 formed thereon, and the plurality of first welding grooves 241 intersect at one intersection position. With this configuration of the first current collecting member 24, on the one hand, the welding area between the first current collecting member 24 and the tab 231 can be further increased, and on the other hand, the main region 242 defined by the plurality of first welding grooves 241 is connected to the second current collecting member 25, which contributes to reducing the difficulty of connecting the first current collecting member 24 and the second current collecting member 25.

[0110] In some embodiments of the present application, the intersection point is the center point of the first current collecting member 24, as shown in FIG.

[0111] The intersecting position is the center position of the first current collecting member 24. That is, all of the multiple first welding grooves 241 extend along the radial direction of the first current collecting member 24, and the multiple first welding grooves 241 intersect at the center position of the first current collecting member 24.

[0112] In some embodiments, a first central hole 243 is provided at the intersection, and the first central hole 243 penetrates both sides of the first current collecting member 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 the first central hole 243 at the intersection where multiple first welding grooves 241 intersect and making the diameter of the first central hole 243 equal to the width of the first welding groove 241, on the one hand, it is possible to guide the electrolyte to a certain extent and improve the wetting effect of the electrolyte on the electrode assembly 23, and on the other hand, it is possible to guide and discharge gas 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 usability of the battery cell 20.

[0113] 4, a central passage 2321 is provided inside the electrode assembly 23, and 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 232 of the electrode assembly 23 and penetrates the tabs 231 located at both ends of the main body 232. A second central hole 251 is provided at the center of the second current collecting member 25, and the second central hole 251 penetrates the second current collecting member 25 along the thickness direction X of the end cover. The central passage 2321, the first central hole 243, and the second central hole 251 communicate with each other, contributing to the discharge of gas and the entry of electrolyte.

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

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

[0116] A plurality of flow guide holes 244 are provided in at least one main region 242, that is, the flow guide holes 244 are provided in at least one of the regions of the first current collecting member 24 defined by the first weld grooves 241.

[0117] Optionally, the area defined by the outer edge of the first current collecting member 24 is S1, the total area of ​​the plurality of flow guide holes 244 is S4, and S1 and S4 satisfy 0.2≦S4 / S1≦0.5, i.e., the plurality of flow guide holes 244 occupy 20% to 50% of the area of ​​the first current collecting member 24.

[0118] If the ratio of the total area of ​​the flow guide holes 244 to the area of ​​the first current collecting member 24 is set to 0.2 to 0.5, on the one hand, it is possible to alleviate the poor electrolyte conduction effect caused by an insufficient total area of ​​the flow guide holes 244, and on the other hand, it is possible to reduce the risk of insufficient structural strength of the first current collecting member 24 and insufficient welding area between the first current collecting member 24 and the tab 231 caused by an excessively large area of ​​the first current collecting member 24 occupied by the flow guide holes 244.

[0119] The diameter of the flow guide holes 244 is D4, which satisfies the relationship 0.1 mm≦D4≦10 mm. Setting the diameter of the flow guide holes 244 to 0.1 mm to 10 mm reduces the risk of insufficient structural strength of the first current collecting member 24 due to the flow guide holes 244 being too large, and also alleviates the situation in which it is difficult for the electrolyte to pass through due to the flow guide holes 244 being too small.

[0120] In some embodiments, as shown in FIG. 6 , there are two first welding grooves 241, and the two first welding grooves 241 divide the first current collecting member 24 into four main regions 242, of which two opposing main regions 242 are connected to the second current collecting member 25, and the remaining two opposing main regions 242 have flow guide holes 244.

[0121] Two first welding grooves 241 are provided in the first current collecting member 24, and the two welding grooves divide the first current collecting member 24 into four main areas 242, with two opposing main areas 242 connected to the second current collecting member 25 and flow guide holes 244 provided in the other two opposing main areas 242. This structure is simple and easy to achieve, and can contribute to reducing the difficulty of processing the first current collecting member 24 and the difficulty of assembling the battery cell 20.

[0122] For example, 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 collecting member 24.

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

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

[0125] A second welding area is formed at the position of the second current collecting member 25 where the second welding groove 252 is provided; that is, the location of the second current collecting member 25 where the second welding groove 252 is located is used for welding to the first current collecting member 24; that is, the groove bottom wall of the second welding groove 252 is welded to the first current collecting member 24, the groove bottom wall of the second welding groove 252 is the second welding area, and the groove bottom wall of the second welding groove 252 is used to connect to the main body area 242 of the first current collecting member 24 where the flow guide hole 244 is not provided, thereby realizing the connection between the second current collecting member 25 and the first current collecting member 24.

[0126] 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 collecting member 25, and each end of the second welding groove 252 extends to the outer edge of the second current collecting member 25. Of course, in other embodiments, the number of second welding grooves 252 provided in the second current collecting member 25 may be three, four, five, etc.

[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 collecting member 25, and a second welding area for welding to the first current collecting 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 serves as a positioning role when welding the second current collecting member 25 and the first current collecting member 24, making it easier to weld between the second current collecting member 25 and the first current collecting member 24, and on the other hand, it contributes to penetrating the second current collecting member 25 during welding, contributing to ensuring the quality of the welding between the second current collecting member 25 and the first current collecting member 24.

[0129] 6, 7, and 8 in some embodiments of the present application, Fig. 8 is a plan view of a second current collecting member 25 connected to a first current collecting member 24 according to some embodiments of the present application. A plurality of first welding grooves 241 are provided on the surface of the first current collecting member 24 facing the second current collecting member 25 along the thickness direction X of the end cover, and the plurality of first welding grooves 241 intersect at the center position of the first current collecting member 24, and the plurality of first welding grooves 241 divide the first current collecting member 24 into a plurality of main body regions 242. Each second welding region is welded to one of the main body regions 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 being located within the corresponding main body region 242 means that the area 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 body region 242.

[0131] For example, two first welding grooves 241 are provided in the first current collecting member 24, and the two first welding grooves 241 divide the first current collecting member 24 into four main regions 242. Similarly, two second welding grooves 252 are provided in the second current collecting member 25, and the two second welding grooves 252 are symmetrical with respect to the center position of the second current collecting member 25, so that 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 collecting member 25 is S2, the total area of ​​the second welded region of the second current collecting member 25 is S5, and S2 and S5 satisfy 0.05≦S5 / S2≦0.3. That is, the second weld groove 252 occupies 5% to 30% of the area of ​​the second current collecting member 25. If the ratio of the total area of ​​the second welded region to the area of ​​the second current collecting member 25 is set to 0.05 to 0.3, on the one hand, it is possible to suppress insufficient current conduction due to an insufficient connection area between the second current collecting member 25 and the first current collecting member 24, and on the other hand, it is possible to alleviate insufficient connection area between the second current collecting member 25 and the end cover 22 due to an excessively large area occupied by the second welded region.

[0133] A plurality of first welding grooves 241 are provided in the first current collecting member 24, and the plurality of welding grooves divide the first current collecting member 24 into a plurality of main regions 242. The main regions 242 are welded to second welding regions formed by second welding grooves 252 in the second current collecting member 25. This allows the projection of the second welding grooves 252 in the thickness direction X of the end cover to be contained within the corresponding main region 242. This structure not only contributes to reducing the difficulty of welding the second current collecting member 25 and the first current collecting member 24, but also reduces interference with the first welding grooves 241 of the first current collecting member 24 when the second current collecting member 25 is welded to the first current collecting member 24.

[0134] In some embodiments of the present application, the embodiments of the present application further provide a battery 100. The battery 100 includes a housing 10 and a battery cell 20 according to any one of the above-described solutions, and the battery cell 20 is housed in the housing 10.

[0135] In some embodiments of the present application, the embodiments of the present application further provide an electric device, which includes the battery 100 according to any one of the above proposals, and the battery 100 provides electric energy to the electric device.

[0136] The electrical device is any one of the devices or systems described above that uses battery 100.

[0137] In some embodiments of the present application, as shown in FIGS. 3 to 8 , the present application provides a battery cell 20. The battery cell 20 includes a housing 21, an end cover 22, an electrode assembly 23, a first current collecting member 24, and a second current collecting member 25, with the first current collecting member 24 and the second current collecting member 25 being separate from each other. The housing 21 has an opening 211, and the end cover 22 is installed to cover the opening 211. The electrode assembly 23 is accommodated in 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 collecting member 24 is connected to the tab 231, and the second current collecting member 25 is connected to the end cover 22. The first current collecting member 24 and the second current collecting member 25 are connected to overlap each other along the thickness direction X of the end cover, with the second current collecting member 25 located on the side of the first current collecting member 24 facing the end cover 22 and the projection of the second current collecting member 25 located within the outer edge of the first current collecting member 24. Both the first current collecting member 24 and the second current collecting member 25 are circular. The electrode assembly 23 includes a main body 232, with the 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, which satisfies the relationships 0.1 mm≦D3−D1≦5 mm and 5 mm≦D3−D2≦10 mm. Two first welding grooves 241 are formed in the surface of the first current collecting member 24 facing the second current collecting member 25 along the thickness direction X of the end cover, and first welding regions are formed in the first current collecting member 24 at the positions where the first welding grooves 241 are formed, and the first welding regions are welded to the tabs 231. Both of the two first welding grooves 241 extend along the radial direction of the first current collecting member 24 and penetrate the outer edge of the first current collecting member 24. The two first welding grooves 241 are perpendicular to each other and intersect at the center of the first current collecting member 24, thereby dividing the first current collecting member 24 into four main body regions 242. Of the four main body regions 242, two opposing main body regions 242 are connected to the second current collecting member 25, and the remaining two opposing main body regions 242 are provided with flow guide holes 244.

[0138] Unless there is a contradiction, the embodiments and features in the embodiments in this application can be combined with each other.

[0139] The above is only a preferred embodiment of the present application and does not limit the present application. Those skilled in the art may have various modifications and variations to the present application. As long as they do not deviate from the spirit and scope of the present application, all modifications, equivalent replacements, improvements, etc., made are included in the protection scope of the present application. [Explanation of symbols]

[0140] 1000 vehicles 100 batteries 10. Housing 11 First housing body 12 Second housing body 20 battery cells 21 Housing 211 Aperture 22 End cover 221 Insulating materials 222 Electrode terminal 223 Pressure Relief Mechanism 23 Electrode Assembly 231 tabs 232 Main body 2321 Center aisle 24 First current collecting member 241 First welding groove 242 Subject area 243 1st center hole 244 Direction hole 25 Second current collecting member 251 2nd center hole 252 Second welding groove 200 control device 300 Engine X Thickness direction of end cover

Claims

1. The battery includes a housing, an end cover, an electrode assembly, a first current collecting member, and a second current collecting member, the housing has an opening; the end cover is disposed to cover the opening, the electrode assembly is housed within the housing and has a tab; the first current collecting member and the second current collecting member are formed separately from each other, the first current collecting member is connected to the tab, and the second current collecting member is connected to the end cover, the first current collecting member and the second current collecting member are connected to overlap each other along the thickness direction of the end cover, the second current collecting member is located on the side of the first current collecting member facing the end cover, and a projection of the second current collecting member in the thickness direction of the end cover is located within the outer edge of the first current collecting member; At least one first welding groove is provided on a surface of the first current collecting member facing the second current collecting member along a thickness direction of the end cover, a first welding area is formed on the first current collecting member at a position where the first welding groove is provided, and the first welding area is welded to the tab, A plurality of the first welding grooves are provided on the first current collecting member, the plurality of first welding grooves intersect at an intersection position, the plurality of first welding grooves divide the first current collecting member into a plurality of main body regions, the plurality of main body regions are configured at intervals around the intersection position, and at least one of the main body regions is connected to the second current collecting member. Battery cell.

2. The area defined by the outer edge of the first current collecting member is S １ and the area defined by the outer edge of the second current collecting member is S ２ and S １ and S ２ That is, 0.6≦S ２ / S １ Satisfying ≦0.9 The battery cell according to claim 1 .

3. the first current collecting member and the second current collecting member are both circular, The outer diameter of the first current collecting member is D １ and the outer diameter of the second current collecting member is D ２ and D １ and D ２ That is, D １ >D ２ fulfill The battery cell according to claim 1 .

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

5. The area defined by the outer edge of the first current collecting member is S １ and the total area of ​​the first welding region of the first current collecting member is S ３ and S １ and S ３ That is, 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 collecting member. The battery cell according to claim 1 .

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

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

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

10. At least one of the main body regions is provided with a plurality of flow guide holes, which penetrate both sides of the first current collecting 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 collecting member is S １ and the total area of ​​the plurality of flow guide holes is S ４ and S １ and S ４ That is, 0.2≦S ４ / S １ Satisfying ≦0.5 The battery cell of claim 10.

12. The diameter of the flow guide hole is D ４ and D ４ is 0.1 mm≦D ４ Meets ≦10mm The battery cell of claim 10.

13. There are two first weld grooves, and the first current collecting member is divided into four main regions by the two first weld grooves. Of the four main regions, two opposing main regions are connected to the second current collecting member, and the flow guide holes are provided in the other two opposing main regions. The battery cell of claim 10.

14. The battery includes a housing, an end cover, an electrode assembly, a first current collecting member, and a second current collecting member, the housing has an opening; the end cover is disposed to cover the opening, the electrode assembly is housed within the housing and has a tab; the first current collecting member and the second current collecting member are formed separately from each other, the first current collecting member is connected to the tab, and the second current collecting member is connected to the end cover, the first current collecting member and the second current collecting member are connected to overlap each other along the thickness direction of the end cover, the second current collecting member is located on the side of the first current collecting member facing the end cover, and a projection of the second current collecting member in the thickness direction of the end cover is located within the outer edge of the first current collecting member; at least one second welding groove is provided on a surface of the second current collecting member facing the end cover along a thickness direction of the end cover, a second welding area is formed on the second current collecting member at a position where the second welding groove is provided, and the second welding area and the first current collecting member are welded together; a plurality of first weld grooves are provided on a surface of the first current collecting member facing the second current collecting member along a thickness direction of the end cover, the plurality of first weld grooves intersect at a center position of the first current collecting member, and the plurality of first weld grooves divide the first current collecting member into a plurality of main regions; Each of the second welding regions is welded to one of the main body regions, and a projection of each of the second welding grooves in the thickness direction of the end cover is located within the corresponding main body region. Battery cell.

15. The area defined by the outer edge of the second current collecting member is S ２ and the total area of ​​the second welding region of the second current collecting member is S ５ and S ２ and S ５ That is, 0.05≦S ５ / S ２ Satisfying ≦0.3 The battery cell of claim 14.

16. The housing and The battery cell according to any one of claims 1 to 15, The battery cell is housed in the housing. battery.

17. 17. A battery comprising the battery of claim 16. Electrical equipment.

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