Battery cells, batteries and electrical devices

Abstract

The present application provides a battery cell, a battery, and an electric device, and belongs to the technical field of batteries. The battery cell 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, and the end cover is installed to cover the opening. The electrode assembly is accommodated in 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 a projection of the second current collecting member is located within the outer edge of the first current collecting member. Such a battery cell can, on the one hand, reduce the contact resistance between the first current collecting member and the tab, thereby reducing the discharge rate of the battery cell, and on the other hand, suppress the occurrence of localized overcurrent between the first current collecting member and the tab, thereby reducing the risk of temperature rise inside the battery cell.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to 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] TECHNICAL FIELD 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 been developing rapidly, and in the field of electric vehicles, power batteries play an important role as the power source of electric vehicles. With the spread of new energy vehicles, the demand for power battery products is also increasing. As a core component of new energy vehicles, batteries are subject to high requirements in terms of 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 a method such as winding or stacking, placing the assembly in a housing, covering the assembly with an end cover, and injecting an electrolyte. However, batteries according to conventional technology have poor performance in use and relatively large safety issues during use, which is disadvantageous for popularization and use. 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, the battery cell comprising 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 installed to cover the opening, the electrode assembly is accommodated in 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, 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 each other in an overlapping manner along a thickness direction of the end cover, the second current collecting member is located on a side of the first current collecting member facing the end cover, and a projection of the second current collecting member is 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, so that 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, an electrical connection between the electrode assembly and the end cover can be realized. 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, that is, 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 between the first current collecting member and the tab and improving the connection stability. On the one hand, the contact resistance between the first current collecting member and the tab is reduced, which contributes to reducing the charge and discharge rate of the battery cell and improves 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 improves 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 S 1and 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 ≦0.9.

[0008] In the above technical proposal, by setting the area ratio between the second current collecting member and the first current collecting member to be 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 the area of ​​the second current collecting member being too large can be reduced, improving the ease of assembly between the end cover and the second current collecting member, and on the other hand, it is possible to mitigate the situation where the current conduction area between the first and second current collecting members becomes too small due to the area of ​​the second current collecting member being too small.

[0009] In some embodiments, the first current collecting member and the second current collecting member are both circular, and 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 By D 1 >D 2 Meet the following.

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

[0011] In some embodiments, the electrode assembly includes a body portion, the tab is disposed to protrude from an end of the body portion facing the end cover, the body portion is cylindrical, and the body portion has an outer diameter D 3 and 0.1mm≦D 3 -D 1 ≦5mm, 5mm≦D 3 -D 2 Meets ≦10mm.

[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 set to 0.1 mm to 5 mm, on the one hand, interference between the first current collecting member and the housing caused by the first current collecting member being too large can be suppressed, and on the other hand, a shortage of the connection area between the first current collecting member and the tab caused by the first current collecting member being too small 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 set to 5 mm to 10 mm, on the one hand, the interference effect of the second current collecting member on the end cover during assembly caused by the second current collecting member being too large can be alleviated, and on the other hand, a shortage of the current conduction area between the second current collecting member and the first current collecting member caused by the second current collecting member being too small can be alleviated.

[0013] In some embodiments, at least one first welding groove is provided along the thickness direction of the end cover on a 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 role in positioning when welding the first current collecting member and the tab, making welding easier and improving welding accuracy, and on the other hand, it contributes to penetrating the first current collecting member during welding, contributing to ensuring the quality of the welding.

[0015] In some embodiments, the area defined by the outer edge of the first current collecting member is S 1 and the total area of ​​the first welded region of the first current collecting member is S 3 And S 1 and S. 3 That is, 0.05≦S 3 / S 1 ≦0.3.

[0016] In the above technical proposal, by setting the ratio of the total area of ​​the first welding region to the area of ​​the first current collecting member to 0.05 to 0.3, on the one hand, it is possible to suppress an insufficiency in the welding area between the first current collecting member and the tab caused by the total area of ​​the first welding region being too small, and on the other hand, it is possible to alleviate an insufficiency in the area of ​​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, thereby contributing to an increase in 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 can ensure the welding area and welding stability between the first current collecting member and the tab, and improve the effect 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 the first weld grooves, the plurality of the first weld grooves intersect at an intersection position, the plurality of the first weld grooves divide the first current collecting member into a plurality of main body regions, the plurality of the main body regions are spaced apart around the intersection position, and at least one of the main body regions is connected to the second current collecting member.

[0022] In the above technical proposal, 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. 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 location is a center location of the first current collecting member.

[0024] In the above technical solution, by making the multiple first welding grooves intersect at the center position of the first collecting member, it is possible to ensure that the tab can be welded to the first collecting member even at different radial positions of the first collecting member, thereby improving the welding area and welding stability, and thereby effectively improving the current conduction performance between the tab and the first 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 a thickness direction of the end cover, and a diameter of the first central hole is equal to a width of the first weld groove.

[0026] In the above technical solution, a first central hole is provided at the intersection position where multiple first welding grooves intersect, and the diameter of the first central hole is the same as the width of the first welding groove, which 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 contribute to guiding and discharging gas generated inside the battery cell or smoke generated during welding through the first central hole and the first welding groove, thereby improving the usage performance 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, the flow guide holes penetrating both sides of the first current collecting member along a thickness direction of the end cover.

[0028] In the above technical proposal, by providing a flow guide hole in the main area 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 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 ≦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 flow guide effect on the electrolyte 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 excessive area of ​​the first current collecting member occupied by the flow guide holes.

[0031] In some embodiments, the diameter of the flow hole is D 4 and D 4 D is 0.1mm or less 4 Meets ≦10mm.

[0032] In the above technical proposal, if the diameter of the flow guide hole 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 the flow guide hole having an excessively large diameter, and on the other hand, it is possible to improve the situation in which it is difficult for the electrolyte to pass through the flow guide hole caused by the flow guide hole having an excessively small diameter.

[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 body regions, and of the four main body regions, two opposing main body regions are connected to the second current collecting member, and the flow guide holes are provided in the other two opposing main body 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 body regions, two opposing main body regions are connected to the second current collecting member, and flow guide holes are provided in the other two opposing main body regions. Such a structure is simple and can be easily realized, 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 along the thickness direction of the end cover on the surface of the second current collecting member facing 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 for welding to the first current collecting member is formed at the location where the second welding groove is located. With such a structure, on the one hand, the second welding groove plays a role in positioning when welding the second current collecting member and the first current collecting member, making it easier to weld the second current collecting member and the first current collecting member, and 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 a corresponding one of the main body regions.

[0038] In the above technical proposal, a plurality of first welding grooves are provided on the first current collecting member, and the first current collecting member is divided into a plurality of main regions by the plurality of welding grooves, and the main regions are welded to second welding regions formed by the 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. Such a 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 S 2 and the total area of ​​the second welded region of the second current collecting member is S 5 And S 2 and S. 5 That is, 0.05≦S 5 / S 2 ≦0.3.

[0040] In the above technical proposal, by setting the ratio of the total area of ​​the second welding region to the area of ​​the second current collecting member to 0.05 to 0.3, on the one hand, it is possible to suppress a lack of current conduction caused by an excessively small connection area between the second current collecting member and the first current collecting member, and on the other hand, it is possible to alleviate a lack of 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-mentioned battery cell, the battery cell being housed in the housing.

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

[0043] In order to more clearly describe the technical solutions of the embodiments of the present application, the drawings used in the embodiments are 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 description of the drawings]

[0044] [Figure 1] FIG. 1 is a schematic diagram of a vehicle according to some embodiments of the present application. [Diagram 2] FIG. 1 is an exploded view illustrating the configuration of a battery according to some embodiments of the present application. [Diagram 3] FIG. 2 is an exploded view illustrating a 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. [Diagram 5] 2 is a schematic diagram illustrating a connection between a first current collecting member and a second current collecting member according to some embodiments of the present application. FIG. [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 PREFERRED EMBODIMENTS

[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 described below with reference to the drawings used in the embodiments of the present application. The described embodiments are only some embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all embodiments obtained by those skilled in the art without using inventive ability also belong to the protection scope 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 only for describing specific embodiments and are not intended to limit the present application. The terms "include", "have" and any variations thereof in the specification, claims and the above description of the drawings of this application mean inclusion without exclusion. The terms "first", "second", and the like in the specification, claims and the above description of the drawings of this application are only intended to distinguish different elements and do not stipulate a particular order or primary and secondary.

[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 the term in various parts of the specification does not necessarily refer to the same embodiment, nor is it intended to limit an independent embodiment or an alternative embodiment that is mutually exclusive with other embodiments.

[0048] In the description of this application, unless otherwise specified, the terms "attached", "coupled", "connected" and "attached" should be understood in a broad sense. For example, they may be fixedly connected, detachably connected, or integrally connected. They may be directly connected, indirectly connected via an intermediate object, or the insides of two elements may communicate with each other. Those skilled in the art can understand the specific meanings of the above terms in this application according to the specific circumstances.

[0049] The term "and / or" used in this application is merely for the purpose of explaining the relationship of related objects and represents three kinds 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 denote like parts, and detailed descriptions of like parts in different embodiments will be omitted for simplicity. The dimensions such as thickness, length, etc. of various parts in the embodiments of the present application shown in the drawings, and the dimensions such as thickness, length, etc. of the entire integrated device are for illustrative purposes only and are not intended to limit the present application.

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

[0052] In the present 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, etc., but is not limited thereto in the embodiments of the present application. The battery cell may be cylindrical, flat, rectangular or other shape, but is not limited thereto in the embodiments of the present application. The battery cell is generally divided into three types according to the packaging method, namely, a cylindrical battery cell, a prismatic battery cell, and a soft-pack battery cell, but is not limited thereto in the embodiments of the present application.

[0053] The battery described in the embodiments of the present application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery described in the present application includes a battery module or a battery pack. The battery generally includes a housing for packaging one or more battery cells or a plurality of battery modules. The housing can prevent liquid or other foreign matter from affecting the charging and discharging of the battery cells.

[0054] The battery cell includes a housing, an electrode assembly, and an electrolyte, and the housing is configured to accommodate the electrode assembly and the electrolyte. The electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator. The battery cell functions mainly by the movement of metal ions between the positive electrode plate and the negative electrode plate. The positive electrode plate includes a positive electrode collector and a positive electrode active material layer, and the positive electrode active material layer is applied to the surface of the positive electrode collector. The portion of the positive electrode collector where the positive electrode active material layer is not applied is a positive electrode tab, and the positive electrode tab realizes the input and output of electric energy to the positive electrode plate. Taking a lithium-ion battery as an example, the material of the positive electrode collector is aluminum, and the positive electrode active material is lithium cobalt oxide, lithium iron phosphate, ternary lithium, lithium manganate, or the like. The negative electrode plate includes a negative electrode collector and a negative electrode active material layer, the negative electrode active material layer is applied to the surface of the negative electrode collector, and the part of the negative electrode collector where the negative electrode active material layer is not applied is the negative electrode tab, and the negative electrode tab realizes the input and output of electric energy of the negative electrode plate. The material of the negative electrode collector can be copper, and the negative electrode active material can be carbon-based or silicon-based, etc. In order to ensure that they do not melt when a large current flows, the positive electrode tab is a multi-layered laminate, and the negative electrode tab is a multi-layered laminate.

[0055] The material of the separator may be PP (polypropylene) or PE (polyethylene), etc. Also, the electrode assembly may have a wound structure or a laminated structure, and the embodiment of the present application is not limited thereto.

[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, and are an important component of the development of new energy. 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, with the development of battery technology, the requirements for the performance and safety of use of the battery are becoming higher. Therefore, the performance and safety of the battery are determined by the performance and safety of use 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 tab of the electrode assembly to the end cover, thereby making the end cover a positive output terminal or a negative output terminal of the battery cell. To facilitate the electrical connection between the tab of the electrode assembly and the end cover, a current collector is usually installed in the housing, and the current collector is connected to each of the end cover and the tab of the electrode assembly (the tab is a full tab, which is flattened and connected to the current collector), thereby realizing the electrical connection between the electrode assembly and the end cover. The greater the feed amount for flattening the tab (i.e., the greater the amount of flattening and pressing the tab), the larger the area of ​​the tab, but the greater the feed amount for flattening, the more difficult it is to weld the tab to the current collector, and the less stable the welding between the tab and the current collector is. In the prior art, in order to ensure the effectiveness of the electrical connection between the electrode assembly and the end cover, a disk sleeve is attached around 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 with this structure is affected by the end cover, the area of ​​the current collector is relatively small, the difficulty of welding the current collector to the tab is still relatively high, and poor welding between the current collector and the tab of the electrode assembly is likely to occur, which is disadvantageous to improving the stability of the connection between the current collector and the tab. Therefore, on the one hand, the contact resistance between the current collector and the tab of the electrode assembly is still relatively large, and the charge / discharge rate of the battery cell is relatively high, which is disadvantageous to improving the usage performance of the battery cell; on the other hand, local overcurrent is likely to occur between the current collector and the tab of the electrode assembly during use, which leads to the risk of an internal temperature rise of the battery cell, which is disadvantageous to improving the usage safety of the battery cell.

[0058] In view of the above, in order to solve the problem of relatively low performance and safety in use of the battery cell, the inventors have 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 accommodated in 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 each other in an overlapping manner 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 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, that is, the area of ​​the first current collecting member is larger than the area of ​​the second current collecting member, so that 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 between the first current collecting member and the tab and improving the connection stability. 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 improves the usage performance of the battery cell. On the other hand, the occurrence of local overcurrent between the first current collecting member and the tab is reduced, which contributes to reducing the risk of temperature rise inside the battery cell, and improves 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, etc. The battery cells and batteries according to the present application can be used to configure a power supply system for 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 an electric device that uses a battery as a power source. 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 one, for example, a game console, an electric car toy, an electric boat toy, and an electric plane toy, etc. 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 taken 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 includes a fuel vehicle, a natural gas vehicle, or a new energy vehicle, and the new energy vehicle includes an electric vehicle, a hybrid vehicle, or a range-extended electric vehicle, etc. 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 driving 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, used to supply electricity for starting, navigation, and operation during driving of the vehicle 1000.

[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 traction power source to provide traction power to the vehicle 1000 in place of or in part in place of gasoline or natural gas.

[0065] 2 is an exploded view showing a configuration of a battery 100 according to some embodiments of the present application. The battery 100 includes a housing 10 and a battery cell 20, where the battery cell 20 is housed within the housing 10. The housing 10 provides an assembly space for the battery cell 20 and may use various configurations. In some embodiments, the housing 10 includes a first housing body 11 and a second housing body 12, where the first housing body 11 and the second housing body 12 together define an assembly space for housing the battery cell 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 cylinder or a rectangle.

[0066] The battery 100 may have 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 fact that 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 an integrated assembly of the plurality of battery cells 20 may be housed in the housing 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 further connecting the plurality of battery modules in series or in parallel, or in a manner including both, to form an integrated assembly, and housed in the housing 10. The battery 100 may further include other structures, for example, the battery 100 may further include a bus bar member for electrically connecting the plurality of battery cells 20 to each other.

[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 of 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 showing a configuration of a battery cell 20 according to some embodiments of the present application, Fig. 4 is an exploded view showing a configuration of a current collecting member according to some embodiments of the present application, and Fig. 5 is a schematic diagram showing 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 a second current collecting member 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 accommodated 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. Along the thickness direction X of the end cover, the first current collecting member 24 and the second current collecting member 25 are overlapping and connected, 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, in other words, 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 as the material for the first current collecting member 24 and the second current collecting member 25, such as copper, nickel, aluminum, etc. The thickness of the first current collecting member 24 and the thickness of the second current collecting member 25 are 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, and the like.

[0074] When assembling the battery cell 20, the electrode assembly 23 is first inserted into the housing 21, the housing 21 is filled with an electrolyte, and the end cover 22 is then installed to cover the opening 211 of the housing 21 to form a hermetic connection and form a hermetic space to accommodate 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 is located on the side of the end cover 22 facing the electrode assembly 23. In the process of assembling the battery cell 20, the insulating member 221 covers the outer periphery of the second current collecting member 25 when the end cover 22 is installed to cover the opening 211 of the housing 21, thereby providing insulating protection for the second current collecting member 25 and playing a role in positioning 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, a rectangle, etc. The shape of the housing 21 is determined based on the specific shape of the electrode assembly 23. For example, when the electrode assembly 23 has a cylindrical structure, the housing 21 uses a cylindrical structure, and when the electrode assembly 23 has a rectangular structure, the housing 21 uses a rectangular structure. Exemplarily, 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 to form a sealed connection, forming a sealed space that contains the electrode assembly 23 and the electrolyte. An electrode terminal 222 is installed on the end cover 22, and the electrode terminal 222 and the end cover 22 are insulated and connected, that is, no current flows between the electrode terminal 222 and the end cover 22. The electrode assembly 23 has tabs 231 (positive electrode tab and negative electrode tab, respectively) on both ends in the thickness direction X of the end cover, and the two tabs 231 are respectively connected to the electrode terminal 222 and the end of the housing 21 remote from the end cover 22 to 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 the housing 21 may be directly connected, for example, by welding or abutting, or the tab 231 may be connected via another component, for example, by welding or abutting the other 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 at an 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, and for example, the second current collecting member 25 is directly welded or abutted to the electrode terminal 222, thereby realizing an electrical connection between the second current collecting member 25 and the electrode terminal 222. Of course, the second current collecting member 25 may be indirectly connected to the electrode terminal 222 of the end cover 22, and for example, the second current collecting member 25 is welded or abutted to the 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 that contains the electrode assembly 23 and the electrolyte. In an embodiment in which the housing 21 has a hollow structure with both ends open, an electrode terminal 222 is 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 serve as a positive output electrode and a negative output electrode of the battery cell 20, respectively. Furthermore, in a battery cell 20 of 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. Exemplarily, 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 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, 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 an 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, that is, the area of ​​the first current collecting member 24 is larger than the area of ​​the second current collecting member 25. As a result, it is only necessary to assemble the second current collecting member 25 and the end cover 22 in the process of assembling the battery cell 20. 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 contributes 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 improves the usage performance of the battery cell 20. On the other hand, the occurrence of local overcurrent between the first current collecting member 24 and the tab 231 is reduced, which contributes to reducing the risk of temperature rise inside the battery cell 20 and improves 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 S 1 and the area defined by the outer edge of the second current collecting member 25 is S 2 And S 1 and S. 2 That is, 0.6≦S 2 / S 1 ≦0.9.

[0085] 0.6≦S 2 / S 1 ≦0.9 indicates that 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 in the thickness direction X of the end cover is 60% to 90%.

[0086] By setting the area ratio between the second current collecting member 25 and the first current collecting member 24 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 assembly between 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 mitigated.

[0087] In some embodiments of the present application, as shown in FIG. 4 and FIG. 5, the first current collecting member 24 and the second current collecting member 25 are both circular, and the outer diameter of the first current collecting member 24 is D 1 and the outer diameter of the second current collecting member 25 is D 2 and D 1 and D 2 By D 1 >D 2 Meet the following.

[0088] Both the first current collecting member 24 and the second current collecting member 25 have a disk-shaped structure. 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, their manufacture is easy, which contributes to reducing the difficulty of assembly.

[0090] In some embodiments of the present application, as shown in Figures 3 and 4, the electrode assembly 23 includes a main body 232, the 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. 3 and 0.1mm≦D 3 -D 1 ≦5mm, 5mm≦D 3 -D 2 The relationship is ≦10 mm.

[0091] 0.1mm≦D 3 -D1 ≦5 mm means that the diameter of the first current collecting member 24 is smaller than the diameter of the main body 232 by 0.1 mm to 5 mm, and 5 mm≦D 3 -D 2 ≦10 mm indicates that the diameter of second current collecting member 25 is smaller than the diameter of main body portion 232 by 5 mm to 10 mm.

[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 respectively connected to the electrode terminals 222 in the end cover 22 and the housing 21, thereby realizing the input and output of electrical energy to the battery cell 20.

[0093] The tab 231 is flattened at one end of the body portion 232 such that the tab 231 protrudes from one end of the body portion 232 , and the flattened tab 231 has a cylindrical structure and a diameter equal to the diameter of the body portion 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 collecting member 24 to 0.1 mm to 5 mm, on the one hand, interference between the first current collecting member 24 and the housing 21 caused by the first current collecting member 24 being too large can be suppressed, and on the other hand, a shortage of the connection area between the first current collecting member 24 and the tab 231 caused by the first current collecting member 24 being too small can be alleviated, thereby ensuring the current conduction area between the first current collecting member 24 and the tab 231. Similarly, by 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 one hand, the interference effect of the second current collecting member 25 on the end cover 22 during assembly caused by the second current collecting member 25 being too large can be alleviated, and on the other hand, a shortage of the 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 can be suppressed.

[0095] 4, 5 and 6, in some embodiments of the present application, Fig. 6 is a plan view 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 where the first welding groove 241 is located, 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 such a structure, on the one hand, the first welding groove 241 plays a role in positioning 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 weld.

[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 S 1 and the total area of ​​the first welded region of the first current collecting member 24 is S 3 And S 1 and S. 3 That is, 0.05≦S 3 / S 1 ≦0.3.

[0100] 0.05≦S 3 / S 1≦0.3 indicates that the first weld 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, on the one hand, it is possible to suppress an insufficiency in the welding area between the first current collecting member 24 and the tab 231 caused by an excessively small total area of ​​the first welding region, and on the other hand, it is possible to alleviate an insufficiency in the area of ​​the first current collecting member 24 for connecting to the second current collecting member 25 caused by an excessively large area occupied by the first welding region in the first current collecting member 24.

[0102] In some embodiments of the present application, as shown in FIG. 6, the first weld 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, that is, 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 position of the first current collecting member 24 to the outer edge of the first current collecting member 24. Both ends of the first welding groove 241 penetrate the outer edge of the first current collecting member 24, so that the first welding area formed by the first welding groove 241 extends from the center position of the first current collecting member 24 to the outer edge of the first current collecting member 24, which can ensure the welding area and welding stability between the first current collecting member 24 and the tab 231, and can improve the effect of current conduction between the first current collecting member 24 and the tab 231.

[0105] If the first welding groove 241 is configured 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, thereby contributing to an increase in 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 body regions 242, the plurality of main body regions 242 are configured at intervals around the intersection position, and at least one of the main body regions 242 is connected to the second current collecting member 25.

[0107] The multiple first welding grooves 241 intersect at an intersection position, that is, 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, whereby 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 partitioned into multiple regions, i.e., main body regions 242, and the multiple main body 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 angles, such as 60 degrees, 70 degrees, or 80 degrees.

[0109] A plurality of first welding grooves 241 are provided in the first current collecting member 24, 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 body region 242 defined by the plurality of first welding grooves 241 is connected to the second current collecting member 25, contributing 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 location is the center location 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 the multiple first welding grooves 241 intersect 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, 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 contribute to guiding and discharging 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 usage performance of the battery cell 20.

[0113] 4, a central passage 2321 is provided inside the electrode assembly 23, the central passage 2321 penetrating the electrode assembly 23 along the thickness direction X of the end cover, and the central passage 2321 is provided in the body portion 232 of the electrode assembly 23 and is provided so as to penetrate the tabs 231 located at both ends of the body portion 232. A second central hole 251 is provided at the center position of the second current collecting member 25, the second central hole 251 penetrating the second current collecting 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 communicate with each other to contribute 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 ensured 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 of the main regions 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 S 1 The total area of ​​the plurality of flow guide holes 244 is S 4 And S 1 and S. 4 That is, 0.2≦S 4 / S 1 ≦0.5. In other words, the plurality of flow guide holes 244 occupies 20% to 50% of the area of ​​the first current collecting member 24.

[0118] By setting the ratio of the total area of ​​the flow guide holes 244 to the area of ​​the first current collecting member 24 to be 0.2 to 0.5, on the one hand, it is possible to alleviate the poor flow guide effect on the electrolyte caused by the total area of ​​the flow guide holes 244 being too small, 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 guide hole 244 is D 4 and D 4 D is 0.1mm or less 4 If the diameter of the flow guide hole 244 is set to 0.1 mm to 10 mm, on the one hand, the risk of insufficient structural strength of the first current collecting member 24 caused by the flow guide hole 244 being too large in diameter can be reduced, and on the other hand, the situation in which it is difficult for the electrolyte to pass through because the diameter of the flow guide hole 244 is too small can be improved.

[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 body regions 242, of which two opposing main body regions 242 are connected to the second current collecting member 25, and the remaining two opposing main body 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 body regions 242, with two opposing main body regions 242 connected to the second current collecting member 25, and flow guide holes 244 are provided in the other two opposing main body regions 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 permitted 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, Fig. 7 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 a 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 area is formed on the second current collecting member 25 at a position where the second welding groove 252 is provided, and the second welding area 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, i.e., 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, i.e., 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 for connecting 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, the two second welding grooves 252 are provided around the center position (second central hole 251) of the second current collecting member 25 at intervals in the circumferential direction, and each of both ends of the second welding grooves 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 weld groove 252 has a length of 20mm to 200mm, a width of 3mm to 10mm, and a depth of 0.1mm to 3mm.

[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 such a structure, on the one hand, the second welding groove 252 plays a role in positioning when welding the second current collecting member 25 and the first current collecting member 24, making it easier to weld 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, and contributes to ensuring the quality of the welding between the second current collecting member 25 and the first current collecting member 24.

[0129] In some embodiments of the present application, reference is made to Fig. 6, Fig. 7 and Fig. 8, and Fig. 8 is a plan view of the second current collecting member 25 according to some embodiments of the present application when it is connected to the first current collecting member 24. 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 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 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 body 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, whereby the groove bottom walls (second welding regions) of the two second welding grooves 252 are welded to two opposing main body regions 242 out of the four main body regions 242.

[0132] In some embodiments, the area defined by the outer edge of the second current collecting member 25 is S 2 and the total area of ​​the second welded region of the second current collecting member 25 is S 5 And S 2 and S. 5 That is, 0.05≦S 5 / S 2 ≦0.3. That is, second welding groove 252 occupies 5% to 30% of the area of ​​second current collecting member 25. When the ratio of the total area of ​​the second welding regions to the area of ​​second current collecting member 25 is set to 0.05 to 0.3, on the one hand, it is possible to suppress a shortage of current conduction caused by an excessively small connection area between second current collecting member 25 and first current collecting member 24, and on the other hand, it is possible to alleviate a shortage of the connection area between second current collecting member 25 and end cover 22 caused by an excessively large area occupied by the second welding regions.

[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 contributes to reducing the difficulty of welding the second current collecting member 25 and the first current collecting member 24, and also suppresses 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-mentioned solutions, the battery cell 20 being housed within the housing 10.

[0135] In some embodiments of the present application, the embodiments of the present application further provide an electric device, which includes a battery 100 according to any one of the above schemes, 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, and the first current collecting member 24 and the second current collecting 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 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 in an overlapping manner 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. The first current collecting member 24 and the second current collecting member 25 are both circular. The electrode assembly 23 includes a main body 232, and the tab 231 is 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 D 3 and 0.1mm≦D 3 -D 1 ≦5mm, 5mm≦D 3 -D 2≦10 mm. Two first welding grooves 241 are provided along the thickness direction X of the end cover on the surface of the first current collecting member 24 facing the second current collecting member 25, and a first welding area is formed at the position of the first current collecting member 24 where the first welding grooves 241 are provided, and the first welding area and the tab 231 are welded. 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 position of the first current collecting member 24, thereby dividing the first current collecting member 24 into four main body regions 242, and of the four main body regions 242, two opposing main body regions 242 are connected to the second current collecting member 25, and the other 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 changes to the present application. As long as it does 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. Chassis 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 so as to cover the opening, The electrode assembly is contained 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 is located within the outer edge of the first 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 Meets ≦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 By that I mean, １ >D ２ Fulfill The battery cell according to claim 1 or 2.

4. the electrode assembly includes a body portion, the tab is provided to protrude from an end of the body portion facing the end cover, the body portion being 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. 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. The battery cell according to any one of claims 1 to 4.

6. The area defined by the outer edge of the first current collecting member is S １ and the total area of ​​the first welded region of the first current collecting member is S ３ And S １ and S. ３ That is, 0.05≦S ３ / S １ Meets ≦0.3 The battery cell according to claim 5 .

7. The first welding groove extends along a radial direction of the first current collecting member. The battery cell according to claim 5 or 6.

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

9. A plurality of the first welding grooves are provided on the first current collecting member, the plurality of the first welding grooves intersect at an intersection position, the plurality of the 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. The battery cell according to any one of claims 5 to 8.

10. The intersection position is the center position of the first current collecting member. The battery cell of claim 9 .

11. A first central hole is provided at the intersection, the first central hole penetrates both sides of the first current collecting member along a thickness direction of the end cover, and a diameter of the first central hole is equal to a width of the first welding groove. The battery cell of claim 10.

12. At least one of the main regions is provided with a plurality of flow guide holes, the flow guide holes passing through both sides of the first current collecting member along the thickness direction of the end cover. The battery cell according to any one of claims 9 to 11.

13. 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 Meets ≦0.5 The battery cell of claim 12.

14. The diameter of the flow guide hole is D ４ And D ４ 0.1mm≦D ４ Meets ≦10mm 14. The battery cell according to claim 12 or 13.

15. The first current collecting member has two first weld grooves, and the first current collecting member is divided into four main body regions by the two first weld grooves. Of the four main body regions, two opposing main body regions are connected to the second current collecting member, and the flow guide holes are provided in the remaining two opposing main body regions. The battery cell according to any one of claims 12 to 14.

16. 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, and 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. The battery cell according to any one of claims 1 to 15.

17. a plurality of first welding 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 welding grooves intersect at a center position of the first current collecting member, and 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 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.

17. The battery cell of claim 16.

18. The area defined by the outer edge of the second current collecting member is S ２ and the total area of ​​the second welded region of the second current collecting member is S ５ And S ２ and S. ５ That is, 0.05≦S ５ / S ２ Meets ≦0.3 18. The battery cell according to claim 16 or 17.

19. A housing and The battery cell according to any one of claims 1 to 18, The battery cell is housed in the housing. battery.

20. 20. A battery comprising the battery of claim 19. Electrical equipment.

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