Battery monomer, battery and electric device

Abstract

The utility model provides a battery monomer, a battery and a power utilization device, and belongs to the technical field of batteries. The single battery comprises a shell, an end cover, an electrode assembly, a first current collecting component and a second current collecting component, wherein the first current collecting component and the second current collecting component are arranged in a split mode. The housing has an opening. The end cover covers the opening. The electrode assembly is accommodated in the housing, and the electrode assembly is provided with a tab. The first current collecting component is connected to the tab, and the second current collecting component is connected to the end cover. In the thickness direction of the end cover, the first current collecting component and the second current collecting component are arranged in a stacked mode and connected with each other, the second current collecting component is located on the side, facing the end cover, of the first current collecting component, and the projection of the second current collecting component is located in the outer edge of the first current collecting component. According to the battery monomer, on one hand, the contact resistance between the first current collecting component and the tab can be reduced so as to reduce the charge-discharge rate of the battery monomer, and on the other hand, the phenomenon of local overcurrent between the first current collecting component and the tab can be reduced so as to reduce the risk of temperature rise in the battery monomer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202210521640.1, filed on May 13, 2022, entitled “Battery Cell, Battery and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the field of battery technology, and in particular to a battery cell, a battery, and an electrical device. Background Art

[0004] In recent years, new energy vehicles have developed by leaps and bounds. In the field of electric vehicles, power batteries, as the power source of electric vehicles, play an irreplaceable and important role. With the vigorous promotion of new energy vehicles, the demand for power battery products is also increasing. Among them, batteries, as core components of new energy vehicles, have high requirements in terms of performance and safety. The battery cell of the battery is assembled into an electrode assembly (bare cell) by winding or laminating the positive electrode sheet, the negative electrode sheet and the diaphragm, and then put into the shell, covered with the end cover, and finally injected with the electrolyte. However, the batteries in the prior art have poor performance and great safety hazards during use, which is not conducive to promotion and use. Utility Model Content

[0005] The embodiments of the present application provide a battery cell, a battery, and an electrical device, which can effectively improve the performance and safety of the battery.

[0006] In a first aspect, an embodiment of the present application provides a battery cell, comprising a shell, an end cover, an electrode assembly, a first current collecting member, and a second current collecting member; the shell has an opening; the end cover covers the opening; the electrode assembly is accommodated in the shell, and the electrode assembly has a tab; the first current collecting member and the second current collecting member are separately arranged, the first current collecting member is connected to the tab, and the second current collecting member is connected to the end cover; wherein, along the thickness direction of the end cover, the first current collecting member and the second current collecting member are stacked and connected to each other, 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.

[0007] In the above technical solution, a first current collecting member and a second current collecting member are overlapped and disposed between the electrode assembly and the end cap along the thickness direction of the end cap, and are interconnected. This allows the first current collecting member to connect to the electrode assembly tab, and after the second current collecting member is connected to the end cap, electrical connection between the electrode assembly and the end cap is achieved. The projection of the second current collecting member in the thickness direction of the end cap lies within the outer edge of the first current collecting member. In other words, the area of ​​the first current collecting member is larger than that of the second current collecting member. This allows the battery cell to be assembled by simply assembling the second current collecting member with the end cap, eliminating the area of ​​the first current collecting member from being limited by the end cap. This reduces the difficulty of connecting the first current collecting member to the tab and improves the connection area and stability between the first current collecting member and the tab. This, in turn, reduces the contact resistance between the first current collecting member and the tab, lowering the charge and discharge rates of the battery cell, thereby improving the battery cell's performance. Furthermore, it reduces the risk of local overcurrent between the first current collecting member and the tab, thereby reducing the risk of internal temperature rise in the battery cell and improving its safety.

[0008] In some embodiments, an area defined by an outer edge of the first current collecting member is S1, and an area defined by an outer edge of the second current collecting member is S2, satisfying 0.6≤S2 / S1≤0.9.

[0009] In the above technical solution, by setting the area ratio of the second current collecting member to the first current collecting member at 0.6 to 0.9, on the one hand, the interference of the second current collecting member on the end cover during assembly due to the excessive area of ​​the second current collecting member can be reduced, thereby improving the installation convenience between the end cover and the second current collecting member. On the other hand, the phenomenon of too small a flow guide area between the first current collecting member and the second current collecting member due to the excessively small area of ​​the second current collecting member can be alleviated.

[0010] 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, and the outer diameter of the second current collecting member is D2, satisfying D1>D2.

[0011] In the above technical solution, by setting the first current collecting member and the second current collecting member to be circular, manufacturing is facilitated and the difficulty of assembly is reduced.

[0012] In some embodiments, the electrode assembly includes a main body, the electrode tab is protruding from one end of the main body facing the end cover, and the main body is a cylinder; wherein the outer diameter of the main body is D3, satisfying 0.1mm≤D3-D1≤5mm, 5mm≤D3-D2≤10mm.

[0013] In the above technical solution, by setting the difference between the diameter of the main body of the electrode assembly and the diameter of the first current collecting member to 0.1 mm to 5 mm, this can reduce interference between the first current collecting member and the housing caused by an oversized first current collecting member. It can also alleviate the insufficient connection area between the first current collecting member and the tab caused by an undersized first current collecting member, thereby ensuring a sufficient flow conduction area between the first current collecting member and the tab. Similarly, by setting the difference between the diameter of the first current collecting member and the second current collecting member to 5 mm to 10 mm, it can reduce interference with the end cap during assembly caused by an oversized second current collecting member. It can also reduce the insufficient flow conduction area between the second and first current collecting members caused by an undersized second current collecting member.

[0014] In some embodiments, along the thickness direction of the end cover, at least one first welding groove is provided on the surface of the first current collecting member facing the second current collecting member, and a first welding area is formed at the position where the first welding groove is provided on the first current collecting member, and the first welding area is welded to the tab.

[0015] In the above technical solution, a first welding groove is provided on the first current collecting member, and the position of the first welding groove forms a first welding area for welding with the tab. This structure enables the first welding groove to play a positioning role when the first current collecting member is welded to the tab, so as to facilitate welding and improve welding accuracy. On the other hand, it is easy to penetrate the first current collecting member during welding, which is beneficial to ensuring welding quality.

[0016] 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 0.05≤S3 / S1≤0.3 is satisfied.

[0017] In the above technical solution, by setting the ratio of the total area of ​​the first welding zone to the area of ​​the first current collecting member to 0.05 to 0.3, on the one hand, the phenomenon of insufficient welding area between the first current collecting member and the tab due to the total area of ​​the first welding zone being too small can be reduced. On the other hand, the situation of insufficient area of ​​the first current collecting member for connection with the second current collecting member due to the first welding zone occupying too large an area of ​​the first current collecting member can be alleviated.

[0018] In some embodiments, the first welding groove extends in a radial direction of the first current collecting member.

[0019] In the above technical solution, by setting the first welding groove to extend 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 is beneficial to increase the welding area between the first current collecting member and the electrode tab.

[0020] In some embodiments, both ends of the first welding groove pass through an outer edge of the first current collecting member.

[0021] In the above technical solution, by passing both ends of the first welding groove through the outer edge of the first current collecting component, the first welding area formed by the first welding groove can extend from the center position of the first current collecting component to the outer edge of the first current collecting component, thereby facilitating the guarantee of the welding area and welding stability between the first current collecting component and the electrode tab, thereby improving the flow conduction effect between the first current collecting component and the electrode tab.

[0022] In some embodiments, the first current collecting member is provided with a plurality of the first welding grooves, the plurality of the first welding grooves intersect at an intersection position, the plurality of the first welding grooves separate the first current collecting member into a plurality of main areas, the plurality of the main areas are spaced around the intersection position, and at least one of the main areas is connected to the second current collecting member.

[0023] In the above technical solution, by providing multiple first welding grooves on the first current collecting component, and the multiple first welding grooves are compared to an intersection position, the first current collecting component of this structure can, on the one hand, further increase the welding area between the first current collecting component and the electrode tab, and on the other hand, enable the main area separated by the multiple first welding grooves to be connected to the second current collecting component, which is beneficial to reducing the difficulty of connecting the first current collecting component and the second current collecting component.

[0024] In some embodiments, the intersection position is a center position of the first current collecting member.

[0025] In the above technical solution, by intersecting multiple first welding grooves at the center position of the first current collecting component, it is beneficial to ensure that the electrode tab can be welded to the first current collecting component at different positions in the radial direction of the first current collecting component, so as to increase the welding area and welding stability, thereby effectively improving the flow conduction performance between the electrode tab and the first current collecting component.

[0026] In some embodiments, a first center hole is provided at the intersection position, the first center hole passes through 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 groove width of the first welding groove.

[0027] In the above technical solution, a first center hole is opened at the intersection of multiple first welding grooves, and the diameter of the first center hole is the same as the width of the first welding groove. On the one hand, it can play a certain guiding role in the electrolyte to improve the effect of the electrode assembly being infiltrated by the electrolyte. On the other hand, it is beneficial to guide and discharge the gas generated inside the battery cell or the smoke generated during welding through the first center hole and the first welding groove to improve the performance of the battery cell.

[0028] In some embodiments, at least one of the main body regions is provided with a plurality of flow guide holes, and the flow guide holes penetrate through both sides of the first current collecting member along the thickness direction of the end cover.

[0029] In the above technical solution, by providing guide holes on the main body area of ​​the first current collecting component, the guide holes can allow the electrolyte to enter the tab along the axial direction of the electrode assembly, thereby facilitating the improvement of the electrolyte infiltration effect on the electrode assembly.

[0030] 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 guide holes is S4, and 0.2≤S4 / S1≤0.5 is satisfied.

[0031] In the above technical solution, by setting the ratio of the total area of ​​the guide holes to the area of ​​the first current collecting member to 0.2 to 0.5, on the one hand, the phenomenon of poor electrolyte diversion effect caused by the total area of ​​the guide holes being too small can be alleviated, and on the other hand, the risk of insufficient structural strength of the first current collecting member and insufficient welding area with the tab due to the guide holes occupying too much area of ​​the first current collecting member can be reduced.

[0032] In some embodiments, the diameter of the guide hole is D4, which satisfies 0.1 mm ≤ D4 ≤ 10 mm.

[0033] In the above technical solution, by setting the aperture of the guide hole to 0.1 mm to 10 mm, on the one hand, the risk of insufficient structural strength of the first current collecting component due to the aperture of the guide hole being too large can be reduced, and on the other hand, the phenomenon of difficulty in the passage of the electrolyte due to the aperture of the guide hole being too small can be reduced.

[0034] In some embodiments, there are two first welding grooves, and the two first welding grooves separate the first current collecting member into four main body areas. Two opposite main body areas among the four main body areas are connected to the second current collecting member, and the other two opposite main body areas are provided with the guide holes.

[0035] In the above technical solution, 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 areas, so that two opposite main areas are connected to the second current collecting member. In addition, guide holes are provided in the two opposite main areas. This structure is simple and easy to implement, and is conducive to reducing the difficulty of processing the first current collecting member and the difficulty of assembling the battery cell.

[0036] In some embodiments, along the thickness direction of the end cover, the surface of the second current collecting member facing the end cover is provided with at least one second welding groove, and the second current collecting member is formed with a second welding area at the position where the second welding groove is provided, and the second welding area is welded to the first current collecting member.

[0037] In the above technical solution, a second welding groove is provided on the second current collecting member, and the position of the second welding groove forms a second welding area welded to the first current collecting member. This structure enables the second welding groove to play a positioning role when the second current collecting member is welded to the first current collecting member, so as to facilitate the mutual welding of the second current collecting member and the first current collecting member. On the other hand, it is convenient to penetrate the second current collecting member during welding, which is beneficial to ensuring the welding quality between the second current collecting member and the first current collecting member.

[0038] In some embodiments, along the thickness direction of the end cover, a plurality of first welding grooves are provided on the surface of the first current collecting member facing the second current collecting member, and the plurality of first welding grooves intersect at the center position of the first current collecting member, and the plurality of first welding grooves separate the first current collecting member into a plurality of main body areas; wherein each second welding area is welded to one of the main body areas, and the projection of each second welding groove in the thickness direction of the end cover is located within the corresponding main body area.

[0039] In the above technical solution, 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 areas, which can be welded with the second welding area formed by the second welding groove on the second current collecting member, so that the projection of the second welding groove in the thickness direction of the end cover is set in the corresponding main area. This structure is conducive to reducing the difficulty of welding between the second current collecting member and the first current collecting member, and can reduce the phenomenon of interference between the second current collecting member and the first welding groove of the first current collecting member when the second current collecting member is welded to the first current collecting member.

[0040] In some embodiments, an area defined by an outer edge of the second current collecting member is S2, a total area of ​​the second welding region of the second current collecting member is S5, and 0.05≤S5 / S1≤0.3 is satisfied.

[0041] In the above technical solution, by setting the ratio of the total area of ​​the second welding zone to the area of ​​the second current collecting member to 0.05 to 0.3, on the one hand, the phenomenon of insufficient flow conduction caused by the small connection area between the second current collecting member and the first current collecting member can be reduced, and on the other hand, the situation of insufficient connection area between the second current collecting member and the end cover caused by the large area occupied by the second welding zone can be alleviated.

[0042] In a second aspect, an embodiment of the present application further provides a battery, comprising a box and the above-mentioned battery cells; the battery cells are accommodated in the box.

[0043] In a third aspect, an embodiment of the present application further provides an electrical device comprising the above-mentioned battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0045] Figure 1 A schematic structural diagram of a vehicle provided in some embodiments of the present application;

[0046] Figure 2 An exploded view of the structure of a battery provided in some embodiments of the present application;

[0047] Figure 3 An exploded view of the structure of a battery cell provided in some embodiments of the present application;

[0048] Figure 4 A partial cross-sectional view of a battery cell provided in some embodiments of the present application;

[0049] Figure 5 A schematic diagram of the connection between the first current collecting member and the second current collecting member provided in some embodiments of the present application;

[0050] Figure 6 A top view of a first current collecting member provided in some embodiments of the present application;

[0051] Figure 7 A top view of a second current collecting member provided in some embodiments of the present application;

[0052] Figure 8 A top view of a second current collecting member connected to a first current collecting member provided in some embodiments of the present application.

[0053] Icon: 1000-vehicle; 100-battery; 10-casing; 11-first casing body; 12-second casing body; 20-battery cell; 21-casing; 211-opening; 22-end cover; 221-insulating member; 222-electrode terminal; 223-pressure relief mechanism; 23-electrode assembly; 231-ear; 232-main body; 2321-center channel; 24-first current collecting member; 241-first welding groove; 242-main body; 243-first center hole; 244-flow guide hole; 25-second current collecting member; 251-second center hole; 252-second welding groove; 200-controller; 300-motor; X-thickness direction of the end cover. DETAILED DESCRIPTION

[0054] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0055] Unless otherwise defined, all technical and scientific terms used in this application have the same meanings as commonly understood by those skilled in the art to which this application belongs. The terms used in the specification of this application are for the purpose of describing specific embodiments only and are not intended to limit this application. The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship.

[0056] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0057] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," "connected," and "attached" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0058] The term "and / or" in this application simply describes an association between related objects, indicating that three possible relationships exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this application generally indicates that the related objects are in an "or" relationship.

[0059] In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted. It should be understood that the thickness, length, width, and other dimensions of the various components in the embodiments of this application, as well as the overall thickness, length, width, and other dimensions of the integrated device shown in the drawings are merely illustrative and should not constitute any limitation on this application.

[0060] The term "plurality" used in this application refers to two or more (including two).

[0061] In this application, battery cells may include lithium-ion secondary batteries, lithium-ion primary batteries, lithium-sulfur batteries, sodium-lithium-ion batteries, sodium-ion batteries, or magnesium-ion batteries, etc., and the embodiments of this application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of this application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of this application do not limit this.

[0062] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a housing that encloses one or more battery cells or multiple battery modules. The housing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0063] A battery cell consists of a housing, an electrode assembly, and an electrolyte. The housing holds the electrode assembly and electrolyte. The electrode assembly consists of a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by the movement of metal ions between the positive and negative electrode sheets. The positive electrode sheet comprises a positive current collector and a positive active material layer. The positive active material layer is coated on the surface of the positive electrode collector. The portion of the positive electrode collector not coated with the positive active material layer serves as the positive tab, allowing power to be input or output from the positive electrode sheet. For lithium-ion batteries, for example, the positive electrode current collector can be made of aluminum, and the positive active material can be lithium cobalt oxide, lithium iron phosphate, ternary lithium, or lithium manganese oxide. The negative electrode sheet comprises a negative current collector and a negative active material layer. The negative active material layer is coated on the surface of the negative electrode collector. The portion of the negative electrode collector not coated with the negative active material layer serves as the negative tab, allowing power to be input or output from the negative electrode sheet. The negative electrode current collector can be made of copper, and the negative electrode active material can be carbon or silicon, etc. In order to ensure that a large current can pass without melting, the positive electrode tabs are multiple and stacked together, and the negative electrode tabs are multiple and stacked together.

[0064] The material of the isolation film may be PP (polypropylene) or PE (polyethylene), etc. In addition, the electrode assembly may be a wound structure or a laminated structure, but the embodiments of the present application are not limited thereto.

[0065] Batteries have outstanding advantages such as high energy density, low environmental pollution, high power density, long service life, wide adaptability, and low self-discharge coefficient. They are an important component of today's new energy development. The battery cell is assembled by winding or stacking the positive electrode sheet, negative electrode sheet and separator into an electrode assembly (bare cell), which is then installed in a casing, covered with end caps, and finally injected with electrolyte. However, with the continuous development of battery technology, higher requirements have been placed on the performance and safety of batteries. Therefore, the performance and safety of battery cells determine the performance and safety of batteries.

[0066] The inventors discovered that for a typical battery cell, the tabs of the electrode assembly need to be connected to the end caps so that the electrode assembly can be electrically connected to the end caps, thereby using the end caps as the positive or negative output poles of the battery cell. To facilitate the electrical connection between the tabs of the electrode assembly and the end caps, a current collecting tray is typically provided within the housing. The current collecting tray is connected to the end caps and the tabs of the electrode assembly (the tabs are full tabs, which are connected to the current collecting trays after being flattened) to achieve electrical connection between the electrode assembly and the end caps. A greater tab flattening feed rate (i.e., a greater tab flattening and downward pressing size) results in a greater tab area. However, a greater flattening feed rate increases the difficulty of welding the tabs to the current collecting trays, and can also affect the welding stability between the tabs and the current collecting trays. In the prior art, to ensure effective electrical connection between the electrode assembly and the end cap, a disc sleeve is provided on the outer circumference of the current collecting disc. This not only protects the current collecting disc but also increases the diameter of the current collecting disc, ensuring that welding can reach the outermost tab. The increased diameter also pushes the welding area further toward the edge of the winding core, thereby reducing the internal resistance of the battery cell. However, the current collecting disc of this structure is affected by the interference of the end cap, resulting in a smaller area of ​​the current collecting disc, making welding between the current collecting disc and the tab more difficult. As a result, cold welds are easily formed between the current collecting disc and the tab of the electrode assembly, which is not conducive to improving the connection stability between the current collecting disc and the tab. Furthermore, the contact resistance between the current collecting disc and the tab of the electrode assembly is still high, resulting in a high charge and discharge rate of the battery cell, which is not conducive to improving the performance of the battery cell. Furthermore, local overcurrent is easily generated between the current collecting disc and the tab of the electrode assembly during use, causing the risk of internal temperature rise in the battery cell, which is not conducive to improving the safety of the battery cell.

[0067] Based on the above considerations, and to address the issues of low performance and safety in battery cells, the inventors, after in-depth research, have designed a battery cell comprising a housing, an end cap, an electrode assembly, a first current collecting member, and a second current collecting member. The housing has an opening, and the end cap is adapted 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 separate components, with the first current collecting member connected to the tab and the second current collecting member connected to the end cap. Along the thickness of the end cap, the first and second current collecting members are stacked and interconnected. The second current collecting member is located on the side of the first current collecting member facing the end cap, with its projection located within the outer edge of the first current collecting member.

[0068] In the aforementioned battery cell, the first and second current collecting members are overlapped and disposed between the electrode assembly and the end cap along the thickness direction of the end cap, and are interconnected. This allows the first current collecting member to connect to the electrode assembly tab, and after the second current collecting member is connected to the end cap, electrical connection between the electrode assembly and the end cap is achieved. The projection of the second current collecting member in the thickness direction of the end cap is located within the outer edge of the first current collecting member. In other words, the area of ​​the first current collecting member is larger than the area of ​​the second current collecting member. This allows the battery cell to be assembled by simply assembling the second current collecting member with the end cap, eliminating the area of ​​the first current collecting member from being limited by the end cap. This reduces the difficulty of connecting the first current collecting member to the tab and improves the connection area and stability between the first current collecting member and the tab. This, in turn, reduces the contact resistance between the first current collecting member and the tab, lowering the charge and discharge rates of the battery cell, thereby improving the battery cell's performance. Furthermore, it reduces the risk of local overcurrent between the first current collecting member and the tab, thereby reducing the risk of internal temperature rise in the battery cell and improving its safety.

[0069] The battery cells disclosed in the embodiments of this application can be used, but are not limited to, in electrical devices such as vehicles, ships, or aircraft. A power supply system comprising the battery cells and batteries disclosed in this application can be used to construct such electrical devices. This effectively improves the stability and reliability of the connection between the current collecting member and the electrode assembly, thereby enhancing the performance and safety of the battery cells.

[0070] The present invention provides an electric device that uses a battery as a power source. The electric device may be, but is not limited to, a mobile phone, a tablet, a laptop computer, an electric toy, an electric tool, a battery-powered vehicle, an electric car, a ship, a spacecraft, etc. The electric toy may include a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy, and an electric airplane toy, etc. The spacecraft may include an airplane, a rocket, a space shuttle, and a spacecraft, etc.

[0071] For the convenience of description, the following embodiments are described by taking a vehicle 1000 as an example of an electrical device according to an embodiment of the present application.

[0072] Please refer to Figure 1 , Figure 1A schematic structural diagram of a vehicle 1000 provided for some embodiments of the present application. The vehicle 1000 may be a fuel vehicle, a gas vehicle or a new energy vehicle. The new energy vehicle may be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc. A battery 100 is provided inside the vehicle 1000. The battery 100 may be provided at the bottom, head or tail of the vehicle 1000. The battery 100 may be used to power the vehicle 1000. For example, the battery 100 may serve as an operating power source for the vehicle 1000. The vehicle 1000 may further include a controller 200 and a motor 300. The controller 200 is used to control the battery 100 to power the motor 300, for example, to meet the power requirements for starting, navigating and driving the vehicle 1000.

[0073] In some embodiments of the present application, the battery 100 can serve not only as an operating power source for the vehicle 1000, but also as a driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0074] Please refer to Figure 2 , Figure 2 An exploded view of the structure of the battery 100 provided in some embodiments of the present application. The battery 100 includes a case 10 and a battery cell 20, and the battery cell 20 is used to be accommodated in the case 10. The case 10 is used to provide an assembly space for the battery cell 20, and the case 10 can adopt a variety of structures. In some embodiments, the case 10 may include a first case body 11 and a second case body 12, and the first case body 11 and the second case body 12 cover each other, and the first case body 11 and the second case body 12 jointly define an assembly space for accommodating the battery cell 20. The second case body 12 can be a hollow structure with one end open, and the first case body 11 can be a plate-like structure, and the first case body 11 covers the open side of the second case body 12, so that the first case body 11 and the second case body 12 jointly define an assembly space; the first case body 11 and the second case body 12 can also be hollow structures with one side open, and the open side of the first case body 11 covers the open side of the second case body 12. Of course, the box body 10 formed by the first box body 11 and the second box body 12 can be in various shapes, such as a cylinder, a cuboid, etc.

[0075] In the battery 100, there may be multiple battery cells 20, and the multiple battery cells 20 may be connected in series, in parallel, or in a hybrid connection. A hybrid connection refers to a combination of series and parallel connections among the multiple battery cells 20. The multiple battery cells 20 may be directly connected in series, in parallel, or in a hybrid connection, and then the entire battery cell 20 may be housed within the housing 10. Alternatively, the battery 100 may be constructed by first connecting multiple battery cells 20 in series, in parallel, or in a hybrid connection to form a battery module, which is then connected in series, in parallel, or in a hybrid connection to form a complete battery module, and then housed within the housing 10. The battery 100 may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 20.

[0076] Each battery cell 20 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery or a magnesium-ion battery, but is not limited thereto. The battery cell 20 can be cylindrical, flat, rectangular or other shapes. For example, in Figure 2 In the embodiment, the battery cell 20 is cylindrical.

[0077] According to some embodiments of the present application, referring to Figure 3 、 Figure 4 and Figure 5 , Figure 3 This is an exploded view of the structure of the battery cell 20 provided in some embodiments of the present application. Figure 4 This is an exploded view of the structure of the current collecting component provided in some embodiments of the present application. Figure 5 Schematic diagram of the connection between the first current collecting member 24 and the second current collecting member 25 provided in some embodiments of the present application. The present application provides a battery cell 20, comprising a housing 21, an end cap 22, an electrode assembly 23, a first current collecting member 24, and a second current collecting member 25. The housing 21 has an opening 211. The end cap 22 covers the opening 211. The electrode assembly 23 is housed within the housing 21 and has a tab 231. The first current collecting member 24 and the second current collecting member 25 are disposed separately, with the first current collecting member 24 connected to the tab 231 and the second current collecting member 25 connected to the end cap 22. The first current collecting member 24 and the second current collecting member 25 are stacked and interconnected along the thickness direction X of the end cap. The second current collecting member 25 is located on the side of the first current collecting member 24 facing the end cap 22, and its projection is located within the outer edge of the first current collecting member 24.

[0078] Among them, along the thickness direction X of the end cover, the first current collecting member 24 and the second current collecting member 25 are stacked and connected to each other, and the second current collecting member 25 is located on the side of the first current collecting member 24 facing the end cover 22. That is, the first current collecting member 24 and the second current collecting member 25 are overlapped and arranged between the electrode assembly 23 and the end cover 22 along the thickness direction X of the end cover, and the first current collecting member 24 is farther away from the end cover 22 than the second current collecting member 25.

[0079] The projection of the second current collecting member 25 is located within the outer edge of the first current collecting member 24 , that is, along the thickness direction X of the end cover, the projection of the second current collecting member 25 falls within the area defined by the outer edge of the first current collecting member 24 , that is, the area of ​​the second current collecting member 25 is smaller than that of the first current collecting member 24 .

[0080] Optionally, the connection between the first current collecting member 24 and the tab 231, between the first current collecting member 24 and the second current collecting member 25, and between the second current collecting member 25 and the end cover 22 can be mutually abutted or welded. For example, in this embodiment, the first current collecting member 24 and the tab 231, between the first current collecting member 24 and the second current collecting member 25, and between the second current collecting member 25 and the end cover 22 are all welded to each other.

[0081] For example, the first current collecting member 24 and the second current collecting member 25 may be made of various materials, such as copper, nickel, or aluminum, etc. The thickness of the first current collecting member 24 and the thickness of the second current collecting member 25 are both in the range of 0.1 mm to 5 mm.

[0082] Optionally, the housing 21 can also be used to accommodate an electrolyte, such as an electrolyte solution. The housing 21 can have various structural forms. The housing 21 can also be made of various materials, such as copper, iron, aluminum, steel, aluminum alloy, etc.

[0083] When assembling the battery cell 20, the electrode assembly 23 is first placed in the housing 21, and the housing 21 is filled with electrolyte. The end cap 22 is then placed over the opening 211 of the housing 21 to form a sealed connection, thereby forming a sealed space for accommodating the electrode assembly 23 and the electrolyte. Exemplarily, the end cap 22 is welded to the housing 21.

[0084] The end cap 22 is provided with an insulating member 221, which is located on the side of the end cap 22 facing the electrode assembly 23. During assembly of the battery cell 20, the insulating member 221 is used to cover the outer periphery of the second current collecting member 25 when the end cap 22 is closed over the opening 211 of the housing 21, thereby providing insulation protection and positioning for the second current collecting member 25. Exemplary materials for the insulating member 221 include rubber, plastic, or silicone.

[0085] The shell 21 can be in various shapes, such as a cylinder, a cuboid, etc. The shape of the shell 21 can be determined according to the specific shape of the electrode assembly 23. For example, if the electrode assembly 23 is a cylindrical structure, a cylindrical structure can be selected; if the electrode assembly 23 is a cuboid structure, a cuboid structure can be selected. For example, in Figure 3 In the embodiment, the electrode assembly 23 is a cylindrical structure, and the shell 21 is a cylindrical shell 21.

[0086] For example, in Figure 3 In the embodiment, the housing 21 is a hollow structure with an opening 211 at one end. The end cap 22 covers the opening 211 of the housing 21 and forms a sealed connection, thereby forming a sealed space for accommodating the electrode assembly 23 and the electrolyte. The end cap 22 is provided with an electrode terminal 222. The electrode terminal 222 is insulated from the end cap 22, that is, there is no current conduction between the electrode terminal 222 and the end cap 22. The electrode assembly 23 has tabs 231 (a positive tab and a negative tab, respectively) at both ends of the end cap in the thickness direction X. The two tabs 231 are respectively connected to the electrode terminal 222 and the end of the housing 21 away from the end cap 22, serving as the positive and negative output poles of the battery cell 20. Of course, the tabs 231 can be directly connected to the electrode terminal 222 or the housing 21, such as by welding or abutting, or they can be connected through other components. For example, the tabs 231 can be first welded or abutted to other components and then connected to the electrode terminal 222 or the housing 21.

[0087] Along the thickness direction X of the end cap, the tab 231 of the electrode assembly 23 at the end facing the end cap 22 is connected to the first current collecting member 24, and the second current collecting member 25 is connected to the electrode terminal 222 of the end cap 22. It should be noted that the second current collecting member 25 can be directly connected to the electrode terminal 222 of the end cap 22, for example, by being directly welded or abutted against the electrode terminal 222 to achieve electrical connection between the second current collecting member 25 and the electrode terminal 222. Alternatively, the second current collecting member 25 can be indirectly connected to the electrode terminal 222 of the end cap 22, for example, by being welded or abutted against the second current collecting member 25 and the adapter, which is then welded or abutted against the electrode terminal 222.

[0088] It is understood that the battery cell 20 is not limited to the structure described above. The battery cell 20 may also have other structures. For example, the battery cell 20 includes a housing 21 and two end caps 22. The housing 21 is a hollow structure with two opposing openings 211 at each end. One end cap 22 is sealed against one of the openings 211 of the housing 21, thereby forming a sealed space for accommodating the electrode assembly 23 and the electrolyte. In the embodiment in which the housing 21 is a hollow structure with two openings 211 at each end, both end caps 22 are provided with electrode terminals 222. The two electrode terminals 222 are respectively configured to connect to the two tabs 231 of the electrode assembly 23, thereby serving as the positive and negative output electrodes of the battery cell 20. Furthermore, in a battery cell 20 with this structure, the first and second current collecting members 24, 25 may be provided between only one end cap 22 and the electrode assembly 23, or both may be provided between each end cap 22 and the electrode assembly 23. This is not limited in the present embodiment.

[0089] It should be noted that the electrode assembly 23 is the component where the electrochemical reaction occurs in the battery cell 20. The electrode assembly 23 may include a positive electrode sheet, a negative electrode sheet, and a separator. The electrode assembly 23 may be a wound structure formed by winding the positive electrode sheet, the separator, and the negative electrode sheet, or a stacked structure formed by stacking the positive electrode sheet, the separator, and the negative electrode sheet. For example, in Figure 3 In the embodiment, the electrode assembly 23 is a wound structure formed by winding a positive electrode sheet, a separator and a negative electrode sheet.

[0090] In some embodiments, Figure 3 In the embodiment, the battery cell 20 may further include a pressure relief mechanism 223, which may be mounted on the end cap 22 or the housing 21. The pressure relief mechanism 223 is used to release the pressure inside the battery cell 20 when the internal pressure or temperature of the battery cell 20 reaches a predetermined value.

[0091] Exemplarily, the pressure relief mechanism 223 may be a component such as an explosion-proof valve, an explosion-proof disk, an air valve, a pressure relief valve, or a safety valve.

[0092] By overlapping the first current collecting member 24 and the second current collecting member 25 along the thickness direction X of the end cover between the electrode assembly 23 and the end cover 22 and connecting them to each other, the electrical connection between the electrode assembly 23 and the end cover 22 can be achieved after the first current collecting member 24 is connected to the electrode tab 231 of the electrode assembly 23 and the second current collecting member 25 is connected to 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. Therefore, during the assembly process of the battery cell 20, only the second current collecting member 25 and the end cover 22 need to be assembled and matched, so that the area of ​​the first current collecting member 24 is not limited by the end cover 22. This helps to reduce the difficulty of connecting the first current collecting member 24 and the electrode tab 231, and helps to improve the connection area and connection stability between the first current collecting member 24 and the electrode tab 231. On the one hand, it can reduce the contact resistance between the first current collecting member 24 and the electrode tab 231, which helps to reduce the charge and discharge rate of the battery cell 20, thereby improving the performance of the battery cell 20. On the other hand, it can reduce the phenomenon of local overcurrent between the first current collecting member 24 and the electrode tab 231, which helps to reduce the risk of internal temperature rise in the battery cell 20, thereby improving the safety of the battery cell 20.

[0093] According to some embodiments of the present application, the area defined by the outer edge of the first current collecting member 24 is S1, and the area defined by the outer edge of the second current collecting member 25 is S2, satisfying 0.6≤S2 / S1≤0.9.

[0094] Here, 0.6≤S2 / S1≤0.9, that is, in the thickness direction X of the end cover, the ratio of the area defined by the projection of the second current collecting member 25 to the area defined by the projection of the first current collecting member 24 is 60% to 90%.

[0095] By setting the area ratio of the second current collecting member 25 to the first current collecting member 24 at 0.6 to 0.9, on the one hand, the interference of the second current collecting member 25 on the end cover 22 during assembly due to the excessive area of ​​the second current collecting member 25 can be reduced, thereby improving the installation convenience between the end cover 22 and the second current collecting member 25. On the other hand, the phenomenon of too small a flow guide area between the first current collecting member 24 and the second current collecting member 25 due to the excessively small area of ​​the second current collecting member 25 can be alleviated.

[0096] According to some embodiments of the present application, referring to Figure 4 and Figure 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, and the outer diameter of the second current collecting member 25 is D2, satisfying D1>D2.

[0097] The first current collecting member 24 and the second current collecting member 25 are both circular disc-shaped structures. Of course, in other embodiments, the first current collecting member 24 and the second current collecting member 25 can also be other structures, such as elliptical, rectangular or triangular.

[0098] By providing the first current collecting member 24 and the second current collecting member 25 in a circular shape, manufacturing is facilitated and assembly difficulty is reduced.

[0099] According to some embodiments of this application, see Figure 3 and Figure 4 The electrode assembly 23 includes a main body 232, and a tab 231 protruding from one end of the main body 232 facing the end cap 22. The main body 232 is cylindrical. The outer diameter of the main body 232 is D3, which satisfies the following conditions: 0.1 mm ≤ D3 - D1 ≤ 5 mm, and 5 mm ≤ D3 - D2 ≤ 10 mm.

[0100] 0.1 mm ≤ D3 − D1 ≤ 5 mm, that is, the diameter of the first current collecting member 24 is 0.1 to 5 mm smaller than the diameter of the main body 232 , 5 mm ≤ D3 − D2 ≤ 10 mm, and the diameter of the second current collecting member 25 is 5 to 10 mm smaller than the diameter of the first current collecting member 24 .

[0101] Optionally, both ends of the main body 232 are provided with tabs 231 , and the tabs 231 at both ends of the main body 232 are used to connect to the electrode terminals 222 on the end cover 22 and the shell 21 respectively to realize the input or output of electrical energy of the battery cell 20.

[0102] It should be noted that the tab 231 is flattened with one end of the main body 232 so that the tab 231 protrudes from one end of the main body 232. The flattened tab 231 has a cylindrical structure, and the diameter of the flattened tab 231 is equal to the diameter of the main body 232.

[0103] 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, the interference between the first current collecting member 24 and the housing 21 caused by an oversized first current collecting member 24 can be reduced. Furthermore, the insufficient connection area between the first current collecting member 24 and the tab 231 caused by an undersized first current collecting member 24 can be alleviated, thereby ensuring a sufficient flow 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, the interference between the second current collecting member 25 and the end cap 22 during assembly caused by an oversized second current collecting member 25 can be alleviated. Furthermore, the insufficient flow conduction area between the second current collecting member 25 and the first current collecting member 24 caused by an undersized second current collecting member 25 can be reduced.

[0104] According to some embodiments of this application, please refer to Figure 4 and Figure 5 , and please refer to Figure 6 , Figure 6 A top view of the first current collecting member 24 provided in some embodiments of the present application. Along the thickness direction X of the end cap, 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. A first welding area is formed on the first current collecting member 24 at the location where the first welding groove 241 is provided, and the first welding area is welded to the tab 231.

[0105] The first current collecting member 24 has a first welding area formed at the location where the first welding groove 241 is provided. That is, the first current collecting member 24 is used for welding to the tab 231 at the location where the first welding groove 241 is located. In other words, 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 serves as the first welding area.

[0106] 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.

[0107] A first welding groove 241 is provided on the first current collecting member 24, and the position of the first welding groove 241 forms a first welding area for welding with the electrode tab 231. This structure enables the first welding groove 241 to play a positioning role when the first current collecting member 24 and the electrode tab 231 are welded, so as to facilitate welding and improve welding accuracy. On the other hand, it is easy to penetrate the first current collecting member 24 during welding, which is beneficial to ensuring welding quality.

[0108] According to some embodiments of this application, see Figure 6As shown, the area defined by the outer edge of the first current collecting member 24 is S1, and the total area of ​​the first welding region of the first current collecting member 24 is S3, satisfying 0.05≤S3 / S1≤0.3.

[0109] Here, 0.05≦S3 / S1≦0.3, that is, the area occupied by the first welding groove 241 on the first current collecting member 24 is 5% to 30%.

[0110] 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, the phenomenon of insufficient welding area between the first current collecting member 24 and the tab 231 due to the total area of ​​the first welding region being too small can be reduced. On the other hand, the situation of insufficient area of ​​the first current collecting member 24 for connection with the second current collecting member 25 due to the first welding region occupying too large an area of ​​the first current collecting member 24 can be alleviated.

[0111] According to some embodiments of this application, see Figure 6 As shown, the first welding groove 241 extends in the radial direction of the first current collecting member 24 .

[0112] Among them, the radial direction of the first current collecting component 24 refers to the direction from the center position of the first current collecting component 24 to the edge of the first current collecting component 24 or from the edge of the first current collecting component 24 to the center position of the first current collecting component 24, that is, the radial direction of the first current collecting component 24 passes through the center position of the first current collecting component 24 and is perpendicular to the thickness direction X of the end cover.

[0113] In some embodiments, both ends of the first welding groove 241 penetrate the outer edge of the first current collecting member 24. In other words, 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. By having 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 can extend from the center of the first current collecting member 24 to the outer edge of the first current collecting member 24. This helps to ensure the welding area and welding stability between the first current collecting member 24 and the tab 231, thereby improving the flow guidance effect between the first current collecting member 24 and the tab 231.

[0114] By setting the first welding groove 241 to extend along the radial direction of 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 is beneficial to increase the welding area between the first current collecting member 24 and the electrode tab 231.

[0115] According to some embodiments of this application, please continue to refer to Figure 6As shown, the first current collecting member 24 is provided with a plurality of first welding grooves 241 , which intersect at an intersection position. The plurality of first welding grooves 241 separate the first current collecting member 24 into a plurality of main body areas 242 , which are spaced apart around the intersection position, and at least one main body area 242 is connected to the second current collecting member 25 .

[0116] Among them, multiple first welding grooves 241 intersect at the intersection position, that is, the first current collecting component 24 is provided with multiple first welding grooves 241 on the side facing the second current collecting component 25 in the thickness direction X of the end cover, and the multiple welding grooves intersect at an intersection point, which is the intersection position, thereby dividing the side of the first current collecting component 24 facing the second current collecting component 25 in the thickness direction X of the end cover into multiple areas, namely the main area 242, and the multiple main areas 242 are surrounded by the intersection position of the multiple first welding grooves 241.

[0117] For example, in Figure 6 In the embodiment, there are two first welding grooves 241, and the two welding grooves are perpendicular to each other. Of course, in other embodiments, the number of first welding grooves 241 can also be three, four, or five, and the angles between the multiple welding grooves can also be other angles, such as 60 degrees, 70 degrees, or 80 degrees.

[0118] By providing multiple first welding grooves 241 on the first current collecting component 24, and the multiple first welding grooves 241 are compared to an intersection position, the first current collecting component 24 with this structure can, on the one hand, further increase the welding area between the first current collecting component 24 and the tab 231, and on the other hand, enable the main area 242 separated by the multiple first welding grooves 241 to be connected to the second current collecting component 25, which is beneficial to reduce the difficulty of connecting the first current collecting component 24 and the second current collecting component 25.

[0119] According to some embodiments of this application, please continue to refer to Figure 6 As shown, the intersection position is the center position of the first current collecting member 24 .

[0120] The intersection position is the center position of the first current collecting member 24 , that is, the plurality of first welding grooves 241 extend radially of the first current collecting member 24 , so that the plurality of first welding grooves 241 intersect at the center position of the first current collecting member 24 .

[0121] In some embodiments, a first central hole 243 is provided at the intersection. The first central hole 243 extends through both sides of the first current collecting member 24 along the thickness direction X of the end cap. 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 by ensuring that the diameter of the first central hole 243 is equal to the width of the first welding groove 241, the electrolyte can be guided to a certain extent, thereby improving the electrolyte infiltration of the electrode assembly 23. Furthermore, the gas generated within the battery cell 20 or the fume generated during welding can be guided and discharged through the first central hole 243 and the first welding groove 241, thereby improving the performance of the battery cell 20.

[0122] Optionally, in Figure 4 In the embodiment, a central channel 2321 is defined within the electrode assembly 23. Central channel 2321 extends through both ends of the electrode assembly 23 along the thickness direction X of the end cap. Central channel 2321 is located on the main body 232 of the electrode assembly 23 and extends through the tabs 231 at both ends of the main body 232. A second central hole 251 is defined at the center of the second current collecting member 25. Second central hole 251 extends through both sides of the second current collecting member 25 along the thickness direction X of the end cap. Central channel 2321, first central hole 243, and second central hole 251 are all connected to facilitate exhaust and electrolyte entry.

[0123] By intersecting multiple first welding grooves 241 at the center position of the first current collecting component 24, it is beneficial to ensure that the pole tab 231 can be welded to the first current collecting component 24 at different positions in the radial direction of the first current collecting component 24, thereby increasing the welding area and welding stability, and thus effectively improving the flow conduction performance between the pole tab 231 and the first current collecting component 24.

[0124] According to some embodiments of this application, see Figure 6 As shown, at least one main body area 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.

[0125] At least one main body region 242 is provided with a plurality of guide holes 244 , that is, at least one region of the first current collecting member 24 separated by the first welding grooves 241 is provided with the guide holes 244 .

[0126] Optionally, the outer edge of the first current collecting member 24 defines an area S1, and the total area of ​​the plurality of guide holes 244 is S4, satisfying 0.2≤S4 / S1≤0.5. That is, the plurality of guide holes 244 occupy 20% to 50% of the area of ​​the first current collecting member 24.

[0127] By setting the ratio of the total area of ​​the guide holes 244 to the area of ​​the first current collecting member 24 to 0.2 to 0.5, on the one hand, the phenomenon of poor electrolyte diversion caused by the small total area of ​​the guide holes 244 can be alleviated. On the other hand, the risk of insufficient structural strength of the first current collecting member 24 and insufficient welding area with the tab 231 due to the guide holes 244 occupying too much area of ​​the first current collecting member 24 can be reduced.

[0128] The diameter of the guide holes 244 is D4, which satisfies the condition 0.1 mm ≤ D4 ≤ 10 mm. Setting the diameter of the guide holes 244 between 0.1 mm and 10 mm can reduce the risk of insufficient structural strength of the first current collecting member 24 due to an overly large diameter of the guide holes 244, while also reducing the difficulty of electrolyte passage due to an overly small diameter of the guide holes 244.

[0129] In some embodiments, as Figure 6 As shown, there are two first welding grooves 241 , which separate the first current collecting member 24 into four main body areas 242 . Two opposite main body areas 242 among the four main body areas 242 are connected to the second current collecting member 25 , and the other two opposite main body areas 242 are provided with guide holes 244 .

[0130] By setting two first welding grooves 241 on the first current collecting member 24, and the two welding grooves separate the first current collecting member 24 into four main areas 242, so that the two opposite main areas 242 are connected to the second current collecting member 25, and in addition, the two opposite main areas 242 are provided with guide holes 244. This structure is simple and easy to implement, and is conducive to reducing the processing difficulty of the first current collecting member 24 and the assembly difficulty of the battery cell 20.

[0131] Illustratively, 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 .

[0132] By providing the guide holes 244 on the main body region 242 of the first current collecting member 24 , the guide holes 244 can allow the electrolyte to enter the tab 231 along the axial direction of the electrode assembly 23 , thereby facilitating the improvement of the electrolyte infiltration effect on the electrode assembly 23 .

[0133] According to some embodiments of the present application, referring to Figure 4 and Figure 5 , and please refer to Figure 7 , Figure 7A top view of the second current collecting member 25 provided in some embodiments of the present application. Along the thickness direction X of the end cap, the surface of the second current collecting member 25 facing the end cap 22 is provided with at least one second welding groove 252. A second welding area is formed on the second current collecting member 25 at the location where the second welding groove 252 is provided, and the second welding area is welded to the first current collecting member 24.

[0134] The second current collecting member 25 is formed with a second welding area at the position where the second welding groove 252 is set, that is, the second current collecting member 25 is used to be welded to the first current collecting member 24 at the position where the second welding groove 252 is located, that is, the bottom wall of the second welding groove 252 is welded to the first current collecting member 24, and the bottom wall of the second welding groove 252 is the second welding area. The bottom wall of the second welding groove 252 is used to be welded to the main area 242 of the first current collecting member 24 where the guide hole 244 is not set, so as to realize the connection of the second current collecting member 25 to the first current collecting member 24.

[0135] For example, the second welding groove 252 is an arc-shaped structure. Figure 7 In the embodiment, there are two second welding grooves 252, which are circumferentially spaced apart along the center position (second center hole 251) of the second current collecting member 25, and both ends of the second welding grooves 252 extend to the outer edge of the second current collecting member 25. Of course, in other embodiments, the second current collecting member 25 may also be provided with three, four, or five second welding grooves 252.

[0136] Optionally, the length of the second welding groove 252 is 20 mm to 200 mm, the width of the second welding groove 252 is 3 mm to 10 mm, and the depth of the second welding groove 252 is 0.1 mm to 3 mm.

[0137] By arranging a second welding groove 252 on the second current collecting member 25, and forming a second welding area for welding with the first current collecting member 24 at the position where the second welding groove 252 is located, this structure enables the second welding groove 252 to play a positioning role when the second current collecting member 25 and the first current collecting member 24 are welded, so as to facilitate the mutual welding of the second current collecting member 25 and the first current collecting member 24; on the other hand, it is convenient to penetrate the second current collecting member 25 during welding, which is beneficial to ensuring the welding quality between the second current collecting member 25 and the first current collecting member 24.

[0138] According to some embodiments of the present application, referring to Figure 6 and Figure 7 , and please refer to Figure 8 , Figure 8A top view of the second current collecting member 25 connected to the first current collecting member 24 in some embodiments of the present application is provided. Along the thickness direction X of the end cap, 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. These first welding grooves 241 intersect at the center of the first current collecting member 24 and separate the first current collecting member 24 into a plurality of main body regions 242. Each second welding region is welded to a main body region 242, and the projection of each second welding groove 252 in the thickness direction X of the end cap is located within the corresponding main body region 242.

[0139] The projection of each second welding groove 252 in the thickness direction X of the end cover is located in the corresponding main area 242 , that is, the area defined by the projection of a second welding groove 252 in the thickness direction X of the end cover falls into a corresponding main area 242 .

[0140] For example, two first welding grooves 241 are provided on the first current collecting component 24, and the two first welding grooves 241 separate the first current collecting component 24 into four main body areas 242. Similarly, two second welding grooves 252 are provided on the second current collecting component 25, and the two second welding grooves 252 are symmetrically arranged around the center position of the second current collecting component 25, so that the bottom walls of the two second welding grooves 252 (second welding areas) can be welded to two opposite main body areas 242 among the four main body areas 242.

[0141] In some embodiments, the outer edge of the second current collecting member 25 defines an area S2, and the total area of ​​the second welding region of the second current collecting member 25 is S5, satisfying the condition 0.05 ≤ S5 / S1 ≤ 0.3. In other words, the second welding slots 252 occupy 5% to 30% of the area of ​​the second current collecting member 25. By setting the ratio of the total area of ​​the second welding region to the area of ​​the second current collecting member 25 to be between 0.05 and 0.3, insufficient flow guidance caused by a too-small connection area between the second current collecting member 25 and the first current collecting member 24 can be reduced, while insufficient connection area between the second current collecting member 25 and the end cap 22 caused by an excessively large second welding region can also be mitigated.

[0142] A plurality of first welding grooves 241 are provided on the first current collecting member 24, and the plurality of welding grooves separate the first current collecting member 24 into a plurality of main body areas 242. The main body areas 242 can be welded with the second welding areas formed by the second welding grooves 252 on the second current collecting member 25, so that the projection of the second welding grooves 252 in the thickness direction X of the end cover is set in the corresponding main body area 242. This structure is conducive to reducing the difficulty of welding between the second current collecting member 25 and the first current collecting member 24, and can reduce the interference between the second current collecting member 25 and the first current collecting member 24 when the second current collecting member 25 is welded to the first current collecting member 24.

[0143] According to some embodiments of the present application, a battery 100 is further provided. The battery 100 includes a housing 10 and a battery cell 20 according to any of the above solutions. The battery cell 20 is accommodated in the housing 10 .

[0144] According to some embodiments of the present application, an electrical device is further provided, comprising the battery 100 of any of the above solutions, and the battery 100 is used to provide electrical energy to the electrical device.

[0145] The power-consuming device may be any of the aforementioned devices or systems using the battery 100 .

[0146] According to some embodiments of the present application, see Figures 3 to 8As shown, the present application provides a battery cell 20, which includes a housing 21, an end cap 22, an electrode assembly 23, and a first current collecting member 24 and a second current collecting member 25, which are separately provided. The housing 21 has an opening 211, and the end cap 22 covers the opening 211. The electrode assembly 23 is accommodated within the housing 21. The electrode assembly 23 has a tab 231 at one end of the end cap in the thickness direction X. The first current collecting member 24 is connected to the tab 231, and the second current collecting member 25 is connected to the end cap 22. Along the thickness direction X of the end cap, the first current collecting member 24 and the second current collecting member 25 are stacked and connected to each other. The second current collecting member 25 is located on the side of the first current collecting member 24 facing the end cap 22, and its projection 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. The tab 231 is protruding from one end of the main body 232 facing the end cover 22. The main body 232 is cylindrical. The outer diameter of the main body 232 is D3, which satisfies 0.1mm≤D3-D1≤5mm and 5mm≤D3-D2≤10mm. Among them, along the thickness direction X of the end cover, two first welding grooves 241 are provided on the surface of the first current collecting member 24 facing the second current collecting member 25. The first current collecting member 24 is formed with a first welding area at the position where the first welding grooves 241 are provided. The first welding area is welded to the pole ear 231. The two first welding grooves 241 both extend along the radial direction of the first current collecting member 24 and pass through 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 to separate the first current collecting member 24 into four main body areas 242. Two opposite main body areas 242 of the four main body areas 242 are connected to the second current collecting member 25, and the other two opposite main body areas 242 are provided with guide holes 244.

[0147] It should be noted that, unless there is any conflict, the embodiments and features in the embodiments of this application can be combined with each other.

[0148] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Those skilled in the art will readily appreciate that various modifications and variations are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A battery cell, characterized in that: include: a housing having an opening; An end cover, covering the opening; An electrode assembly is contained in the housing, and the electrode assembly has a tab; as well as A first current collecting member and a second current collecting member are separately provided, wherein the first current collecting member is connected to the electrode lug, and the second current collecting member is connected to the end cover; Among them, along the thickness direction of the end cover, the first current collecting member and the second current collecting member are stacked and connected to each other, 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.

2. The battery cell according to claim 1, characterized in that: An area defined by an outer edge of the first current collecting member is S1, and an area defined by an outer edge of the second current collecting member is S2, satisfying 0.6≤S2 / S1≤0.

9.

3. The battery cell according to claim 1, characterized in that: 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, and the outer diameter of the second current collecting member is D2, satisfying D1>D2.

4. The battery cell according to claim 3, characterized in that: The electrode assembly comprises a main body, the electrode ear is protrudingly arranged at one end of the main body facing the end cover, and the main body is a cylinder; Among them, the outer diameter of the main body is D3, which satisfies 0.1mm≤D3-D1≤5mm, 5mm≤D3-D2≤10mm.

5. The battery cell according to any one of claims 1 to 4, characterized in that: Along the thickness direction of the end cover, at least one first welding groove is provided on the surface of the first current collecting member facing the second current collecting member, and a first welding area is formed at the position where the first welding groove is provided, and the first welding area is welded to the tab.

6. The battery cell according to claim 5, characterized in that: An area defined by an outer edge of the first current collecting member is S1, and a total area of ​​the first welding region of the first current collecting member is S3, satisfying 0.05≤S3 / S1≤0.

3.

7. The battery cell according to claim 5, characterized in that: The first welding groove extends in a radial direction of the first current collecting member.

8. The battery cell according to claim 7, characterized in that: Both ends of the first welding groove penetrate through an outer edge of the first current collecting member.

9. The battery cell according to claim 5, characterized in that: The first current collecting member is provided with a plurality of the first welding grooves, the plurality of the first welding grooves intersect at an intersection position, the plurality of the first welding grooves separate the first current collecting member into a plurality of main body areas, the plurality of the main body areas are spaced around the intersection position, and at least one of the main body areas is connected to the second current collecting member.

10. The battery cell according to claim 9, characterized in that: The intersection position is a center position of the first current collecting member.

11. The battery cell according to claim 10, characterized in that: A first center hole is disposed at the intersection position. The first center hole penetrates both sides of the first current collecting member along the thickness direction of the end cover. The diameter of the first center hole is equal to the groove width of the first welding groove.

12. The battery cell according to claim 9, characterized in that: At least one of the main body regions is provided with a plurality of flow guide holes, and the flow guide holes penetrate through both sides of the first current collecting member along the thickness direction of the end cover.

13. The battery cell according to claim 12, characterized in that: The area defined by the outer edge of the first current collecting member is S1, and the total area of ​​the plurality of flow guide holes is S4, satisfying 0.2≤S4 / S1≤0.

5.

14. The battery cell according to claim 12, characterized in that: The diameter of the guide hole is D4, which satisfies 0.1 mm ≤ D4 ≤ 10 mm.

15. The battery cell according to claim 12, characterized in that: There are two first welding grooves, and the two first welding grooves separate the first current collecting member into four main body areas. Two opposite main body areas among the four main body areas are connected to the second current collecting member, and the other two opposite main body areas are provided with the guide holes.

16. The battery cell according to claim 1, characterized in that: Along the thickness direction of the end cover, the surface of the second current collecting member facing the end cover is provided with at least one second welding groove, and the second current collecting member is formed with a second welding area at the position where the second welding groove is provided, and the second welding area is welded to the first current collecting member.

17. The battery cell according to claim 16, characterized in that: 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 areas; Each of the second welding areas is welded to one of the main body areas, 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 area.

18. The battery cell according to claim 16, characterized in that: An area defined by an outer edge of the second current collecting member is S2, and a total area of ​​the second welding region of the second current collecting member is S5, satisfying 0.05≤S5 / S1≤0.

3.

19. A battery, characterized in that: include: Box; as well as The battery cell according to any one of claims 1 to 18, wherein the battery cell is accommodated in the box body.

20. An electrical device, characterized in that: Comprising a battery according to claim 19.

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