Battery monomer and assembly method thereof, battery, power utilization device and assembly component

Abstract

The invention discloses a battery monomer and an assembly method thereof, a battery, a power utilization device and an assembly component. The battery monomer comprises an electrode assembly, a shell, an end cover assembly and a current collecting component, the electrode assembly includes a first tab. The shell is used for accommodating the electrode assembly and is provided with an opening; the end cover assembly covers the opening and is provided with an electrode leading-out part. The current collecting component comprises a tab connecting area and an end cover connecting area, the tab connecting area is used for being connected with the first tab, and the end cover connecting area is welded to the inner side of the electrode leading-out part and forms a first welding part. And the fusion depth of the first fusion welding part formed on the electrode lead-out part is smaller than or equal to the thickness of the electrode lead-out part. Through the mode, the welding reliability of the end cover assembly and the current collecting component can be improved, and the risk of electrolyte leakage caused by cracks formed by welding can be effectively reduced.

Description

Battery cell and assembly method thereof, battery, electrical device and assembly component

Technical field

[0001] The present application relates to the field of battery technology, and in particular to battery cells and assembly methods thereof, batteries, electrical devices, and assembly components. [Background Technology]

[0002] With the development of battery technology, battery cells are being used in more and more fields, and are gradually replacing traditional fossil energy sources in the automotive power sector. Battery cells can store chemical energy and controllably convert it into electrical energy. After the battery is discharged, it can be recharged to activate the active material and continue to be used.

[0003] A battery cell often includes an electrode assembly, a current collecting component, a shell and an end cap assembly. The shell can accommodate the electrode assembly, and the end cap assembly can cover the opening of the shell. When the end cap assembly covers the opening of the shell, it is often necessary to electrically connect to the electrode assembly through the current collecting component. In the existing assembly method of battery cells, welding the end cap assembly and the current collecting component often requires penetration welding from the outside of the end cap assembly. Since the end cap assembly needs to have a certain structural stability, its thickness is relatively thick. At the same time, in order to save space inside the shell, the thickness of the current collecting component is relatively thin. Therefore, external penetration welding requires the molten pool to first pass through the relatively thick end cap assembly before reaching the relatively thin current collecting component, resulting in difficulty in controlling the penetration depth. If the penetration depth is too small, the end cap assembly will not be sufficiently molten, which will create a risk of cold welding between the end cap assembly and the current collecting component, which can easily cause poor connection. If the penetration depth is too great, there is a risk of excessive welding of the end cap assembly and the current collecting component, which may easily lead to incorrect welding between the current collecting component and the electrode assembly or damage to the electrode assembly due to high temperature, and / or may easily lead to excessive cracks at the welding position between the two, increasing the risk of electrolyte leakage from the cracks to the outside of the battery cell.

[0004] [Summary of the invention]

[0005] In view of the above problems, the present application provides a battery cell and an assembly method thereof, a battery, an electrical device and an assembly assembly, which can improve the welding reliability of the end cover assembly and the current collecting component.

[0006] In a first aspect, the present application provides a battery cell, comprising an electrode assembly, a housing, an end cap assembly, and a current collecting component. The electrode assembly comprises a first tab. The housing is configured to house the electrode assembly and has an opening. The end cap assembly covers the opening and is provided with an electrode lead. The current collecting component comprises a tab connection region and an end cap connection region. The tab connection region is configured to connect to the first tab. The end cap connection region is welded to the inner side of the electrode lead to form a first weld. The first weld has a penetration depth on the electrode lead that is less than or equal to the thickness of the electrode lead.

[0007] In the technical solution of the embodiments of the present application, by forming a first weld on the end cap connection area of ​​the current collecting component and setting the penetration depth of the first weld on the electrode lead to be less than or equal to the thickness of the electrode lead, the risks of cold welds and excessive weld penetration can be effectively avoided. Furthermore, when the penetration depth is set to be less than the thickness of the electrode lead, cracks at the weld between the two are less likely to extend to the outer surface of the current collecting component, effectively reducing the risk of leakage, which is beneficial for reducing the defective rate during the battery cell production process and improving the quality of the battery cells.

[0008] In some embodiments, the first welded portion has a penetration depth on the electrode lead portion that is between 1 / 4 and 3 / 4 of the thickness of the electrode lead portion. This approach ensures sufficient connection strength between the electrode lead portion and the current collecting component while leaving a margin for the electrode lead portion, reducing the risk of cracks extending to the outer surface of the end cap assembly.

[0009] In some embodiments, the base material of the electrode lead portion is different from the base material of the current collecting component, and / or the melting point of the base material of the electrode lead portion is greater than the melting point of the base material of the current collecting component. In this manner, different base materials can be used to meet the structural characteristics of the electrode lead portion and the current collecting component. Furthermore, the lower melting point of the base material of the current collecting component helps reduce welding temperatures, while the relatively higher melting point of the base material of the electrode lead portion ensures that the electrode lead portion is not welded through, thereby reducing the risk of leakage.

[0010] In some embodiments, the thermal expansion coefficient of the base material of the electrode lead-out part is smaller than the thermal expansion coefficient of the base material of the current collecting component. Through the above method, the electrode lead-out part adopts a base material with a smaller thermal expansion coefficient, which is beneficial to reducing the stress strain and crack generation of the electrode lead-out part and reducing the risk of leakage.

[0011] In some embodiments, the electrode lead-out base is made of steel, and the current collecting component base is made of copper or aluminum. Using steel as the electrode lead-out base allows for a lower thermal expansion coefficient and improved mechanical strength. Copper or aluminum has a lower melting point than steel, making the current collecting component base of copper or aluminum easier to weld and easier to process and shape.

[0012] In some embodiments, a soldering layer is provided on the surface of the electrode lead-out portion and / or the current collecting component. In this way, the soldering layer is used to improve the welding effect between the current collecting component and the electrode lead-out portion.

[0013] In some embodiments, the electrode lead-out portion includes a base, a solder resist layer is arranged on the base, and at least part of the first welding portion is located in the base. Through the above method, the solder resist layer is used to improve the welding effect of the electrode lead-out portion, and the first welding portion extends into the base, which is beneficial to improving the connection strength.

[0014] In some embodiments, the first welding portion is configured not to penetrate the substrate. By configuring the first welding portion not to penetrate the substrate in the above manner, the risk of liquid leakage can be reduced.

[0015] In some embodiments, the soldering layer includes at least one of nickel or tin. In this way, when the substrate is not easy to weld, the nickel or tin provided on the substrate surface can improve the weldability of the electrode lead portion and improve the welding effect.

[0016] In some embodiments, the first weld is formed from the side of the end cap connection region facing away from the electrode lead portion and extends into the electrode lead portion. By performing welding from the side of the end cap connection region facing away from the electrode lead portion, the welding operation is facilitated and welding through the electrode lead portion is less likely to occur.

[0017] In some embodiments, the tab connection region is welded to the first tab to form a second weld portion, the second weld portion being formed from a side of the tab connection region facing away from the first tab and extending into the first tab. By performing welding from the side of the tab connection region facing away from the first tab, the welding operation can be facilitated.

[0018] In some embodiments, the current collecting component further includes a transition region connected between the tab connection region and the end cap connection region, wherein the transition region is configured to bend relative to the end cap connection region, and the tab connection region is configured to bend relative to the transition region. In this manner, the tab connection region and the end cap connection region are connected via the transition region, providing assembly redundancy for the tab connection region and the end cap connection region, facilitating welding operations.

[0019] In some embodiments, the current collecting component, when laid flat, has a first reference direction and a second reference direction perpendicular to each other, arranged along its main surface. The tab connection region, transition region, and end cap connection region are sequentially arranged along the first reference direction. The first main surface of the end cap connection region is in contact with the electrode lead portion and is welded to the electrode lead portion via a first weld formed on the second main surface of the end cap connection region. This approach increases the connection area between the electrode lead portion and the end cap connection region, facilitating the welding operation.

[0020] In some embodiments, the second major surface of the tab connection region is in contact with the first tab and is welded to the first tab via a second weld formed from the first major surface of the tab connection region, wherein the first major surface of the tab connection region and the first major surface of the end cap connection region are located on the same side of the current collecting component. This facilitates the welding operation and improves assembly efficiency.

[0021] In some embodiments, after the battery cells are assembled, the current collecting component is deployed between the electrode assembly and the end cap assembly. In this deployed state, the tab connection area, transition area, and end cap connection area are arranged non-overlappingly along the axial direction of the battery cells. This approach can reduce the axial dimension of the current collecting component, thereby improving the space utilization of the battery cells.

[0022] In some embodiments, the tab connection region is welded to the first tab to form a second weld. The current collecting component is configured to be bent during battery cell assembly. This allows for a clearance between the end cap assembly and the electrode assembly after one of the first weld and the second weld is formed, thereby allowing for the formation of the other of the first and second welds. This facilitates welding operations and improves assembly efficiency.

[0023] In some embodiments, when bent, a clearance is formed between the end cap assembly and the first major surface of the tab connection area. This allows the end cap assembly and the current collecting component to be pre-assembled and formed, and then the tab connection area and the electrode assembly are welded, thereby improving assembly efficiency.

[0024] In some embodiments, the end cap connection region includes a first sub-end cap connection region and a second sub-end cap connection region. The first sub-end cap connection region is connected to the tab connection region, and the second sub-end cap connection region is connected to the first sub-end cap connection region and is spaced apart from the tab connection region. The first sub-end cap connection region and the second sub-end cap connection region are each welded to the electrode lead portion via a first weld. This increases the welding area between the end cap connection region and the end cap assembly, facilitating a stable connection between the current collecting component and the end cap assembly and meeting flow requirements.

[0025] In some embodiments, the current collecting component further includes a transition region disposed between the first sub-end cap connection region and the tab connection region. When laid flat, the current collecting component has a first reference direction and a second reference direction perpendicular to each other, extending along the main surface of the current collecting component. The tab connection region, the transition region, and the first sub-end cap connection region are sequentially arranged along the first reference direction. The second sub-end cap connection region is located outside the transition region along at least the second reference direction and extends toward the tab connection region. A certain gap is maintained between the second sub-end cap connection region, the transition region, and the tab connection region. This approach increases the connection area between the end cap connection region and the end cap assembly, while improving space utilization. Furthermore, the second sub-end cap connection region and the tab connection region do not interfere with each other.

[0026] In some embodiments, the second sub-end cap connection region further extends to be located outside the tab connection region along the second reference direction. By doing so, the connection area between the end cap connection region and the end cap assembly can be increased while improving space utilization.

[0027] In some embodiments, there is one second sub-end cap connection region, with both ends of the second sub-end cap connection region connected to the first sub-end cap connection region and disposed around the transition region and the tab connection region. This arrangement further increases the connection area between the end cap connection region and the end cap assembly, while also improving the balance and stability of the connection between the end cap connection region and the end cap assembly.

[0028] In some embodiments, there are two second sub-end cap connection areas, which are located at least on opposite sides of the transition area along the second reference direction. By the above method, the balance stability of the connection between the end cap connection area and the end cap assembly can be improved.

[0029] In some embodiments, the tab connection region and the first sub-end cap connection region are each configured in a circular segment shape. This arrangement allows the tab connection region and the first sub-end cap connection region to more easily adapt to the arc-shaped edges of the housing and / or end cap assembly while ensuring the required flow between the tab connection region and the end cap connection region.

[0030] In some embodiments, when the current collecting component is laid flat, the outer edges of the tab connection region and the outer edges of the first sub-end cap connection region are each arc-shaped and cocentric. This facilitates the processing and forming of the current collecting component and makes it easier to adapt to cylindrical or nearly cylindrical battery cells.

[0031] In some embodiments, when the current collecting component is laid flat, the outer edge of the tab connection region is arc-shaped, and a line connecting the two outermost connection points of the first sub-end cap connection region and the transition region along the second reference direction to the center of the outer edge of the tab connection region forms an angle that is smaller than the central angle of the outer edge of the tab connection region. This ensures that the area of ​​the tab connection region capable of connecting to the first tab is sufficient to meet the current requirements.

[0032] In some embodiments, the central angle of the outer edge of the tab connection area is 120-240 degrees, and the included angle is 80-120 degrees. Through the above method, it is possible to simultaneously ensure that the area of ​​the tab connection area can be connected to the first tab and the area of ​​the end cap connection area can be connected to the electrode lead-out portion.

[0033] In some embodiments, when the current collecting component is laid flat, the outer edges of the first sub-end cap connection region and the outer edges of the second sub-end cap connection region are each arc-shaped, co-centered and arranged with equal radii. This facilitates the processing and molding of the current collecting component and makes it easier to adapt to cylindrical or nearly cylindrical battery cells.

[0034] In some embodiments, when the current collecting component is laid flat, the outer edge of the second sub-end cap connection area and the inner edge of the second sub-end cap connection area are arranged in an arc shape and are cocentric with each other. The ratio of the radius of the outer edge of the second sub-end cap connection area to the radius of the inner edge of the second sub-end cap connection area is 1.1-1.3. This approach can increase the connection area between the second sub-end cap connection area and the electrode lead portion while ensuring the flow rate requirement between the end cap connection area and the tab connection area.

[0035] In some embodiments, when the current collecting component is laid flat, the outer edges of the first sub-end cover connection region and the outer edges of the transition region are respectively arranged in an arc shape and are arranged cocentrically with each other. This makes it easier to process and shape the current collecting component.

[0036] In some embodiments, when the current collecting component is in a flat state, the outer edge of the pole tab connection area is arranged in an arc shape, and the current collecting component further has a reference circle with a radius of a line connecting the outermost connection point of the first sub-end cover connection area and the transition area along the second reference direction to the center of the outer edge of the pole tab connection area, and the outer edge of the transition area is located inside the reference circle and is spaced apart from the reference circle. Through the above method, sufficient hollow space is formed between the transition area and the second sub-end cover connection area, thereby reducing the material consumption of the current collecting component and improving the wetting effect of the electrolyte on the electrode assembly.

[0037] In some embodiments, the width of the gap between the outer edge of the transition region and the reference circle along the second reference direction gradually widens from the first sub-end cap connection region to the tab connection region. This approach creates a sufficient hollow space between the transition region and the second sub-end cap connection region, thereby reducing the material consumption of the current collecting component and improving the wetting effect of the electrolyte on the electrode assembly.

[0038] In some embodiments, the transition region is arranged in a trapezoidal shape, and the width of the transition region along the second reference direction gradually widens from the first sub-end cap connection region to the tab connection region. In this manner, sufficient hollow space is formed between the transition region and the second sub-end cap connection region, and the processing and forming of the outer edge of the transition region is facilitated.

[0039] In some embodiments, when the current collecting component is laid flat, when the outer edge of the tab connection region is projected along a first reference direction toward the end cap connection region, the projection of the outermost point of the outer edge of the tab connection region in a second reference direction lies outside the inner edge of the second sub-end cap connection region. This approach ensures that the area of ​​the tab connection region capable of connecting with the first tab is sufficient to meet the overcurrent requirements.

[0040] In some embodiments, the outer edge of the tab connection region and the inner edge of the second sub-end cap connection region are arc-shaped and cocentric, and the radius of the outer edge of the tab connection region is greater than the radius of the inner edge of the second sub-end cap connection region. This ensures that the area of ​​the tab connection region available for connection to the first tab is sufficient, while also facilitating the processing and forming of the current collecting component.

[0041] In some embodiments, the current collecting component is provided with a first trace line and a second trace line along the second reference direction. The first trace line is provided to allow the tab connection region to bend relative to the transition region along the first trace line, and the second trace line is provided to allow the first sub-end cap connection region to bend relative to the transition region along the second trace line. This facilitates bending of the current collecting component.

[0042] In some embodiments, in the flattened state, a first distance is defined between the first trace line and the second trace line along a first reference direction, and a second distance is defined between the second trace line and the outer edge of the first sub-end cap connection region along the first reference direction. The first distance is greater than the maximum value of the second distance, such that, in the bent state, the outer edge of the end cap assembly maintains a predetermined distance from the plane of the first major surface of the tab connection region. This prevents interference between the end cap assembly and the electrode assembly, facilitating welding operations.

[0043] In some embodiments, the ratio of the minimum flow area S of the transition zone to the battery capacity C of the battery cell is greater than or equal to 0.15 mm² / Ah. The minimum flow area of ​​the transition zone is the product of the minimum width of the transition zone along the second reference direction and the thickness of the transition zone. Through the above approach, the flow capacity of the transition zone can meet the current transmission requirements of the electrode assembly and the end cap assembly.

[0044] In some embodiments, the electrode assembly includes a cylindrical electrode body, the outer edge of the tab connection region is arc-shaped, and the ratio of the radius of the outer edge of the tab connection region to the radius of the electrode assembly is greater than or equal to 0.8. This ensures that the area of ​​the tab connection region capable of connecting with the first tab is sufficient to meet the overcurrent requirement.

[0045] In some embodiments, the current collecting component is further provided with a hollow portion. By the above-mentioned method, the material usage of the current collecting component can be reduced and the wetting effect of the electrolyte on the electrode assembly can be improved.

[0046] In some embodiments, the outer edge of the tab connection region is arc-shaped and the hollow portion is located at the center of the outer edge of the tab connection region, or the hollow portion is entirely located within the tab connection region. In this manner, the hollow portion located at the center of the outer edge of the tab connection region can further enhance the electrolyte infiltration effect on the electrode assembly. The hollow portion is entirely located within the tab connection region and can serve as an observation window to assist in positioning.

[0047] In some embodiments, the end cap assembly includes an end cap, the electrode lead portion includes at least a portion of the end cap, and the end cap covers the opening. By using the end cap as the electrode lead portion, the structural complexity of the end cap assembly can be simplified.

[0048] In some embodiments, the electrode lead-out portion includes an annular boss of the end cover protruding toward the electrode assembly, the end cover connection area is welded to the top surface of the annular boss, and the outer edge of the tab connection area overlaps the top surface of the annular boss. Through the above method, the annular boss is used to support the tab connection area, which can reduce the deformation and offset of the current collecting component and improve the structural stability of the battery cell.

[0049] In some embodiments, the outer edge of the tab connection area is arc-shaped, and the radius of the outer edge of the tab connection area is larger than the inner radius of the annular boss and smaller than the outer radius of the annular boss. In this way, while the annular boss supports the tab connection area, interference between the outer edge of the tab connection area and the housing is avoided.

[0050] In some embodiments, the shell is electrically connected to the end cover, the shell includes a bottom wall arranged opposite to the end cover, and the bottom wall is provided with an electrode terminal protruding from the bottom wall. The electrode assembly also includes a second pole ear with opposite polarity to the first pole ear, and the second pole ear is located on the side of the electrode assembly facing the electrode terminal, and the second pole ear is electrically connected to the electrode terminal. Through the above method, the shell and the electrode terminals arranged on the bottom wall of the shell are used as the positive and negative poles of the battery cell, which can simplify the assembly complexity of the battery cell and facilitate the connection of the battery cell with external equipment.

[0051] In a second aspect, the present application provides a battery comprising the battery cell in the above embodiment.

[0052] In a third aspect, the present application provides an electrical device comprising the battery in the above embodiment.

[0053] In a fourth aspect, the present application provides an assembly component of a battery cell, which includes an end cap assembly and a current collecting component, wherein the end cap assembly is provided with an electrode lead-out portion. In a flattened state, the current collecting component has a first reference direction and a second reference direction arranged along the main surface of the current collecting component and perpendicular to each other. The current collecting component includes a tab connection area, a transition area, and an end cap connection area arranged in sequence along the first reference direction. The first main surface of the end cap connection area is in contact with the electrode lead-out portion, and is welded to the battery lead-out portion through a first weld formed from the second main surface of the end cap connection area. The depth of penetration formed by the first weld on the electrode lead-out portion is less than or equal to the thickness of the electrode lead-out portion. In the above manner, by forming the first weld on the end cap connection area of ​​the current collecting component and setting the depth of penetration formed by the first weld on the electrode lead-out portion to be less than or equal to the thickness of the electrode lead-out portion, the risk of cold welding and excessive welding can be effectively avoided. Furthermore, when the penetration depth is set to be smaller than the thickness of the electrode lead-out portion, cracks at the welding position of the two are not likely to extend to the outer surface of the current collecting component, effectively reducing the risk of leakage, which is beneficial to reducing the defective rate of the battery cell production process and improving the quality of the battery cell.

[0054] In some embodiments, the transition region is configured to bend relative to the end cap connection region, and the tab connection region is configured to bend relative to the transition region, so that the current collecting component is in a bent state. In this bent state, a clearance is formed between the end cap and the first major surface of the tab connection region, allowing the tab connection region to be welded to the first tab of the electrode assembly via a second weld formed from the first major surface of the tab connection region when the second major surface of the tab connection region is in contact with the first tab of the electrode assembly. The first major surface of the tab connection region and the first major surface of the end cap connection region are located on the same side of the current collecting component. This facilitates the execution of the welding operation.

[0055] In some embodiments, the current collecting component is configured to be pre-bent into a bent state and to maintain the bent state in the absence of external forces. This allows the current collecting component to be bent into a desired shape before or after the end cap assembly and the current collecting component are assembled, thereby improving subsequent production efficiency.

[0056] In some embodiments, the current collecting component is configured to be deployed into an expanded state when the tab connection region is welded to the first tab and the end cap assembly is attached to the housing housing the electrode assembly. In the expanded state, the tab connection region, the transition region, and the end cap connection region are non-overlapping along the axial direction of the battery cell. This approach can reduce the axial dimension of the current collecting component occupied by the battery cell, thereby improving the space utilization of the battery cell.

[0057] In some embodiments, the end cap connection region includes a first sub-end cap connection region connected to the transition region and a second sub-end cap connection region connected to the first sub-end cap connection region. When laid flat, the second sub-end cap connection region is located outside the transition region along at least the second reference direction and extends toward the tab connection region. A certain gap is maintained between the second sub-end cap connection region, the transition region, and the tab connection region. The first sub-end cap connection region and the second sub-end cap connection region are each welded to the electrode lead portion via a first weld. This approach increases the connection area between the end cap connection region and the end cap assembly, while improving space utilization. Furthermore, the second sub-end cap connection region and the tab connection region do not interfere with each other.

[0058] In some embodiments, the second sub-end cap connection region further extends to be located outside the tab connection region along the second reference direction. By doing so, the connection area between the end cap connection region and the end cap assembly can be further increased, while improving space utilization.

[0059] In some embodiments, there is one second sub-end cap connection region, with both ends of the second sub-end cap connection region connected to the first sub-end cap connection region and disposed around the transition region and the tab connection region. This arrangement further increases the connection area between the end cap connection region and the end cap assembly, while also improving the balance and stability of the connection between the end cap connection region and the end cap assembly.

[0060] In some embodiments, there are two second sub-end cap connection regions, each located at least on opposite sides of the transition region along the second reference direction. This further increases the connection area between the end cap connection region and the end cap assembly, while also improving the balance and stability of the connection between the end cap connection region and the end cap assembly.

[0061] In some embodiments, the tab connection region and the first sub-end cap connection region are each configured in a circular segment shape, with the outer edges of the tab connection region and the first sub-end cap connection region each configured in an arc shape and co-centered with each other. This facilitates the processing and forming of the current collecting component and makes it easier to adapt to cylindrical or nearly cylindrical battery cells.

[0062] In some embodiments, a line connecting the two outermost connection points of the first sub-end cap connection region and the transition region along the second reference direction to the center of the outer edge of the tab connection region forms an angle that is smaller than the central angle of the outer edge of the tab connection region. This approach ensures that the area of ​​the tab connection region capable of connecting to the first tab is sufficient to meet the overcurrent requirement.

[0063] In some embodiments, the outer edge of the second sub-end cap connection region is arc-shaped and cocentric with the outer edge of the first sub-end cap connection region and has the same radius. The inner edge of the second sub-end cap connection region is arc-shaped and cocentric with the outer edge of the first sub-end cap connection region. This facilitates the processing and forming of the current collecting component and makes it easier to adapt to cylindrical or nearly cylindrical battery cells.

[0064] In some embodiments, the current collecting component further comprises a reference circle having a radius extending from a line connecting the outermost connection point between the first sub-end cap connection region and the transition region along the second reference direction to the center of the outer edge of the tab connection region. The outer edge of the transition region is located within the reference circle and spaced apart from the reference circle. This arrangement creates a sufficient hollow space between the transition region and the second sub-end cap connection region, thereby reducing material usage for the current collecting component and improving electrolyte wetting of the electrode assembly.

[0065] In some embodiments, the width of the gap between the outer edge of the transition region and the reference circle along the second reference direction gradually widens from the first sub-end cap connection region to the tab connection region. This approach creates a sufficient hollow space between the transition region and the second sub-end cap connection region, thereby reducing the material consumption of the current collecting component and improving the wetting effect of the electrolyte on the electrode assembly.

[0066] In some embodiments, the transition region is arranged in a trapezoidal shape, and the width of the transition region along the second reference direction gradually widens from the first sub-end cap connection region to the tab connection region. In this manner, sufficient hollow space is formed between the transition region and the second sub-end cap connection region, and the processing and forming of the outer edge of the transition region is facilitated.

[0067] In some embodiments, in the flattened state, when the outer edge of the tab connection region is projected along the first reference direction toward the end cap connection region, the projection of the outermost point of the outer edge of the tab connection region in the second reference direction is located outside the inner edge of the second sub-end cap connection region. This approach ensures that the area of ​​the tab connection region capable of connecting to the first tab is sufficient, thereby meeting the overcurrent requirement.

[0068] In some embodiments, the outer edge of the tab connection region and the inner edge of the second sub-end cap connection region are arc-shaped and cocentric, with the radius of the outer edge of the tab connection region being greater than the radius of the inner edge of the second sub-end cap connection region. This approach ensures that the tab connection region has sufficient area for connection with the first tab, while also facilitating the processing and forming of the current collecting component. Furthermore, it facilitates adaptation to cylindrical or nearly cylindrical battery cells.

[0069] In some embodiments, the current collecting component is provided with a first trace line and a second trace line along a second reference direction. The first trace line is configured to allow the tab connection region to bend relative to the transition region along the first trace line, and the second trace line is configured to allow the first sub-end cap connection region to bend relative to the transition region along the second trace line. In a flattened state, the first trace line and the second trace line are separated by a first distance along the first reference direction, and the second trace line is separated by a second distance along the first reference direction from the outer edge of the first sub-end cap connection region. The first distance is greater than the maximum value of the second distance, so that in the bent state, the outer edge of the end cap maintains a predetermined distance from the plane of the first major surface of the tab connection region. This facilitates bending of the current collecting component while avoiding interference between the end cap assembly and the electrode assembly, thereby facilitating welding operations.

[0070] In some embodiments, the current collecting component is further provided with a hollow portion. By the above-mentioned method, the material usage of the current collecting component can be reduced and the wetting effect of the electrolyte on the electrode assembly can be improved.

[0071] In some embodiments, the outer edge of the tab connection region is arc-shaped, and the hollow portion is located at the center of the outer edge of the tab connection region, or the hollow portion is entirely located within the tab connection region. In this manner, the hollow portion located at the center of the outer edge of the tab connection region can further enhance the electrolyte infiltration effect on the electrode assembly. The hollow portion is entirely located within the tab connection region and can serve as an observation window to assist in positioning.

[0072] In some embodiments, the end cap assembly includes an end cap that covers the opening of the housing. The electrode lead includes an annular boss that protrudes from the end cap toward the electrode assembly. The end cap connection area is welded to the top surface of the annular boss, and after welding, the outer edge of the tab connection area can overlap the top surface of the annular boss. In this way, the annular boss supports the tab connection area, which can reduce deformation and displacement of the current collecting component and improve the structural stability of the battery cell.

[0073] In a fifth aspect, the present application provides a method for assembling the battery cell of the above-mentioned embodiment, the assembly method comprising: providing the above-mentioned assembly assembly, wherein the current collecting component is in a bent state, and in the bent state, a clearance is formed between the end cap assembly and the first main surface of the tab connection area; laminating the second main surface of the tab connection area with the first tab of the electrode assembly; and welding the tab connection area to the first tab from the first main surface of the tab connection area. Through the above-mentioned method, welding the current collecting component to the end cap assembly from the side of the current collecting component can avoid the risks of cold welding and excessive welding caused by welding the current collecting component to the end cap assembly from the outside of the end cap assembly in conventional assembly methods, which is conducive to reducing the defective rate of the battery cell production process and improving the quality of the battery cells.

[0074] In some embodiments, the end cap assembly is mounted on the opening of the housing housing the electrode assembly, such that the current collecting component is positioned between the electrode assembly and the end cap assembly and deployed to an expanded state. In this expanded state, the tab connection area, transition area, and end cap connection area are non-overlapping along the axial direction of the battery cell. This approach reduces the axial dimension of the current collecting component within the battery cell, thereby improving the space utilization of the battery cell.

[0075] In a sixth aspect, the present application provides another assembly method for the battery cell in the above-mentioned embodiment, the assembly method comprising: providing an electrode assembly, an end cap assembly, and a current collecting component, wherein the electrode assembly comprises a first tab, the end cap assembly is provided with an electrode lead-out portion, and the current collecting component comprises a tab connection area and an end cap connection area; forming a first weld for welding the end cap connection area to the electrode lead-out portion, and a second weld for welding the tab connection area to the first tab, wherein the penetration depth formed by the first weld on the electrode lead-out portion is less than the thickness of the electrode lead-out portion. Through the above-mentioned method, welding the current collecting component to the end cap assembly from the side of the current collecting component can avoid the risks of cold welding and excessive welding caused by welding the current collecting component to the end cap assembly from the outside of the end cap assembly in the conventional assembly method, which is beneficial to reducing the defective rate of the battery cell production process and improving the quality of the battery cell.

[0076] In some embodiments, the current collecting component is bent so that after one of the first weld and the second weld is formed, a gap is formed between the end cap assembly and the electrode assembly, thereby forming the other of the first weld and the second weld. This facilitates the welding operation.

[0077] In some embodiments, the first weld is formed from the side of the end cap connection region away from the electrode lead portion, and the second weld is formed from the side of the tab connection region away from the first tab.

Brief Description of the Drawings

[0078] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present application. The same reference numerals are used throughout the drawings to represent the same components. In the drawings:

[0079] FIG1 is a schematic structural diagram of a vehicle according to some embodiments of the present application;

[0080] FIG2 is a schematic diagram of the exploded structure of a battery according to some embodiments of the present application;

[0081] FIG3 is a schematic diagram of the cross-sectional structure of a battery cell according to some embodiments of the present application;

[0082] FIG4 is a schematic structural diagram of part A of the battery cell shown in FIG3 ;

[0083] FIG5 is a schematic diagram of the three-dimensional structure of a current collecting component according to an embodiment of the present application;

[0084] FIG6 is a schematic diagram showing the positional relationship between the current collecting component and the end cover assembly in an assembled state according to an embodiment of the present application;

[0085] FIG7 is a schematic structural diagram of part B of the battery cell shown in FIG3 ;

[0086] FIG8 is a schematic diagram showing the positional relationship among the end cap assembly, the current collecting component, and the electrode assembly during the assembly process of one embodiment of the present application;

[0087] FIG9 is a top view of the current collecting component shown in FIG5 ;

[0088] FIG10 is a top view of a current collecting component according to another embodiment of the present application;

[0089] FIG11 is a top view of a current collecting component according to another embodiment of the present application;

[0090] FIG12 is a schematic diagram showing the positional relationship between the current collecting component and the end cover in an assembled state according to another embodiment of the present application;

[0091] FIG13 is a schematic diagram of a flow chart of an embodiment of a method for assembling a battery cell of the present application;

[0092] FIG14 is a schematic flow chart of another embodiment of a method for assembling a battery cell of the present application.

[0093] The accompanying drawings in the specific implementation manner are as follows:

[0094] 1000a vehicles;

[0095] 100a battery; 200a controller; 300a motor;

[0096] 10a housing; 11a first part; 12a second part;

[0097] 1 Battery cell; 4 Assembly component; 10 Current collecting component; 101 Base of current collecting component; 102 Soldering layer of current collecting component; 110 Tab connection area; 120 Transition area; 130 End cap connection area; 131 First sub-end cap connection area; 132 Second sub-end cap connection area; 136 Weld bead; 140 Reference circle; 150 First trace line; 151 Second trace line; 160 Hollow portion; 20 Electrode assembly; 21 First tab; 22 Second tab; 30 End cap assembly; 31 Electrode lead portion; 32 First weld portion; 33 Second weld portion; 30a End cap; 31a Annular boss; 311 Base of electrode lead portion; 312 Soldering layer of electrode lead portion; 40 Housing; 41 Opening; 42 Bottom wall; 43 Electrode terminal;

[0098] 111 outer edge of the tab connection region; 34 outer edge of the end cap assembly; 134 outer edge of the second sub-end cap connection region; 133 outer edge of the first sub-end cap connection region; 135 inner edge of the second sub-end cap connection region; 121 outer edge of the transition region; 171 first major surface of the end cap connection region; 172 second major surface of the end cap connection region; 173 first major surface of the tab connection region; 174 second major surface of the tab connection region;

[0099] First reference direction D1; second reference direction D2; axial direction D3 of the battery cell; two outermost connection points P1 and P2 between the first sub-end cover connection area and the transition area along the second reference direction; the outermost points P3 and P4 of the outer edge of the tab connection area in the second reference direction; the intersection points P5 and P6 of the reference line parallel to the second reference direction and the two side edges of the transition area; center O; angle θ; central angle α of the outer edge of the tab connection area; first distance d1; second distance d2; interval width d3; width L1 at the connection position between the transition area and the first sub-end cover connection area; distance L2 between the intersection points of the reference line parallel to the second reference direction and the two side edges of the transition area; length L3 of the truncation of the hollow portion; radius R1 of the outer edge of the tab connection area; inner edge radius R2 of the annular boss; outer edge radius R3 of the annular boss. [Specific implementation method]

[0100] The following embodiments of the technical solution of the present application will be described in detail with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present application and are therefore only examples and are not intended to limit the scope of protection of the present application.

[0101] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments 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 figure descriptions are intended to cover non-exclusive inclusions.

[0102] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be understood to indicate or imply relative importance or implicitly specify the quantity, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, the meaning of "plurality" is more than two, unless otherwise clearly and specifically defined.

[0103] References herein to "embodiments" mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present 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. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0104] In the description of the embodiments of this application, the term "and / or" is simply a description of the association relationship between associated objects, indicating that three relationships can exist. For example, A and / or B can represent the following three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this document generally indicates that the associated objects are in an "or" relationship.

[0105] In the description of the embodiments of the present application, the term "multiple" refers to more than two (including two). Similarly, "multiple groups" refers to more than two groups (including two groups), and "multiple pieces" refers to more than two pieces (including two pieces).

[0106] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the embodiments of the present application.

[0107] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0108] With the development of battery technology, battery cells are being used in more and more fields, and are gradually replacing traditional fossil energy sources in the automotive power sector. Battery cells can store chemical energy and controllably convert it into electrical energy. After the battery is discharged, it can be recharged to activate the active material and continue to be used.

[0109] A battery cell often includes an electrode assembly, a current collecting component, a shell and an end cap assembly. The shell can accommodate the electrode assembly, and the end cap assembly can cover the opening of the shell. When the end cap assembly covers the opening of the shell, it is often necessary to electrically connect to the electrode assembly through the current collecting component. In the existing assembly method of battery cells, welding the end cap assembly and the current collecting component often requires penetration welding from the outside of the end cap assembly. Since the end cap assembly needs to have a certain structural stability, its thickness is relatively thick. At the same time, in order to save space inside the shell, the thickness of the current collecting component is relatively thin. Therefore, external penetration welding requires the molten pool to first pass through the relatively thick end cap assembly before reaching the relatively thin current collecting component, resulting in difficulty in controlling the penetration depth. If the penetration depth is too small, the end cap assembly will not be sufficiently molten, which will create a risk of cold welding between the end cap assembly and the current collecting component, which can easily cause poor connection. If the penetration depth is too great, there is a risk of excessive welding of the end cap assembly and the current collecting component, which may easily lead to incorrect welding between the current collecting component and the electrode assembly or damage to the electrode assembly due to high temperature, and / or may easily lead to excessive cracks at the welding position between the two, increasing the risk of electrolyte leakage from the cracks to the outside of the battery cell.

[0110] In order to reduce the problem of poor welding of the end cap assembly, the applicant has found that the electrode assembly includes a first tab. The shell is used to accommodate the electrode assembly, and the shell has an opening. The end cap assembly covers the opening and is provided with an electrode lead-out portion. The current collecting component includes a tab connection area and an end cap connection area. The tab connection area is used to connect to the first tab. The end cap connection area is welded to the inner side of the electrode lead-out portion and forms a first weld. The depth of fusion formed by the first weld on the electrode lead-out portion is less than or equal to the thickness of the electrode lead-out portion, which is convenient for detection when a cold weld occurs, can effectively avoid the occurrence of a cold weld, and can also reduce the risk of excessive welding of the end cap assembly and the current collecting component. Furthermore, when the depth of fusion is set to be less than the thickness of the electrode lead-out portion, cracks at the welding position of the two are not easy to extend to the outer surface of the current collecting component, effectively avoiding leakage of the electrolyte, which is conducive to reducing the defective rate of the battery cell production process and improving the quality of the battery cell.

[0111] The battery cells and assembly methods thereof, batteries, electrical devices, and assembly components disclosed in the embodiments of the present application can be used in electrical devices that use batteries as power sources or various energy storage systems that use batteries as energy storage elements. Electrical devices can be, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, battery-powered vehicles, electric vehicles, ships, spacecraft, and the like. Among them, electric toys can include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, and the like, and spacecraft can include airplanes, rockets, space shuttles, and spacecraft, and the like.

[0112] For the convenience of description, the following embodiments are described by taking a vehicle 1000a as an example of an electrical device according to an embodiment of the present application.

[0113] Referring to Figure 1, vehicle 1000a can be a fuel vehicle, a gas vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid vehicle, or an extended-range vehicle, etc. A battery 100a is provided inside vehicle 1000a. Battery 100a can be provided at the bottom, head, or tail of vehicle 1000a. Battery 100a can be used to power vehicle 1000a. For example, battery 100a can serve as an operating power source for vehicle 1000a. Vehicle 1000a can also include a controller 200a and a motor 300a. Controller 200a is used to control battery 100a to power motor 300a, for example, to meet the power requirements for starting, navigating, and driving the vehicle 1000a.

[0114] In some embodiments of the present application, the battery 100a can serve not only as an operating power source for the vehicle 1000a, but also as a driving power source for the vehicle 1000a, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000a.

[0115] Referring to Figure 2, the battery 100a includes a housing 10a and a battery cell 1, and the battery cell 1 is accommodated in the housing 10a. The housing 10a is used to provide a storage space for the battery cell 1, and the housing 10a can adopt a variety of structures. In some embodiments, the housing 10a can include a first portion 11a and a second portion 12a, and the first portion 11a and the second portion 12a cover each other, and the first portion 11a and the second portion 12a jointly define a storage space for accommodating the battery cell 1. The second portion 12a can be a hollow structure with one end open, and the first portion 11a can be a plate-like structure, and the first portion 11a covers the open side of the second portion 12a, so that the first portion 11a and the second portion 12a jointly define a storage space; the first portion 11a and the second portion 12a can also be hollow structures with one side open, and the open side of the first portion 11a covers the open side of the second portion 12a. Of course, the box body 10a formed by the first part 11a and the second part 12a can be in various shapes, such as a cylinder, a cuboid, etc.

[0116] In battery 100a, there may be multiple battery cells 1, which may be connected in series, in parallel, or in a hybrid configuration. A hybrid configuration refers to a combination of series and parallel connections within the battery cells 1. Multiple battery cells 1 may be directly connected in series, in parallel, or in a hybrid configuration, and then the entire battery cell 1 may be housed within the housing 10a. Alternatively, battery 100a may comprise multiple battery cells 1 connected in series, in parallel, or in a hybrid configuration to form a battery module, which is then further connected in series, in parallel, or in a hybrid configuration to form a single unit housed within the housing 10a. Battery 100a may also include other structures, such as a busbar assembly for electrically connecting the multiple battery cells 1.

[0117] Each battery cell 1 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 1 can be cylindrical, flat, rectangular, or in other shapes.

[0118] Referring to Figure 3 , a battery cell 1 is the smallest unit that makes up a battery. In this embodiment, a cylindrical battery cell is used as an example. As shown in Figure 3 , a battery cell 1 includes an end cap assembly 30 , a housing 40 , an electrode assembly 20 , and other functional components.

[0119] The end cap assembly 30 is a component that covers the opening of the housing 40 to isolate the internal environment of the battery cell 1 from the external environment. The shape of the end cap assembly 30 can be adapted to the shape of the housing 40 to fit the housing 40. Optionally, the end cap assembly 30 can be made of a material with a certain hardness and strength (such as an aluminum alloy). This prevents the end cap assembly 30 from deforming when subjected to compression or collision, thereby providing the battery cell 1 with greater structural strength and improved safety. The end cap assembly 30 can be provided with functional components such as electrode lead-out portions. The electrode lead-out portions can be used to electrically connect to the electrode assembly 20 for outputting or inputting electrical energy into or out of the battery cell 1. In some embodiments, the end cap assembly 30 can also be provided with a pressure relief mechanism for relieving internal pressure when the internal pressure or temperature of the battery cell 1 reaches a threshold. The end cap assembly 30 can also be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any specific limitations on this. In some embodiments, an insulating member may be provided inside the end cap assembly 30 to isolate the electrical connection components in the housing 40 from the end cap assembly 30 to reduce the risk of short circuits. For example, the insulating member may be made of plastic, rubber, or the like.

[0120] The housing 40 is a component that cooperates with the end cap assembly 30 to form the internal environment of the battery cell 1. This internal environment can be used to accommodate the electrode assembly 20, electrolyte, and other components. The housing 40 and the end cap assembly 30 can be separate components. An opening can be provided in the housing 40, and the end cap assembly 30 is placed over the opening to form the internal environment of the battery cell 1. Alternatively, the end cap assembly 30 and the housing 40 can be integrated. Specifically, the end cap assembly 30 and the housing 40 can form a common connection surface before other components are inserted into the housing. When the interior of the housing 40 is to be enclosed, the end cap assembly 30 is placed over the housing 40. The housing 40 can be of various shapes and sizes, such as a rectangular parallelepiped, a cylinder, or a hexagonal prism. Specifically, the shape of the housing 40 can be determined based on the specific shape and size of the electrode assembly 20. The housing 40 can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., and this embodiment of the present application does not impose any particular limitations on this.

[0121] The electrode assembly 20 is a component in the battery cell 1 where electrochemical reactions occur. One or more electrode assemblies 20 may be contained in the housing 40. The electrode assembly 20 is mainly formed by winding or stacking positive and negative electrode sheets, and a separator is usually provided between the positive and negative electrode sheets. The parts of the positive and negative electrode sheets with active materials constitute the main body of the electrode assembly, and the parts of the positive and negative electrode sheets without active materials each constitute a tab. The positive tab and the negative tab may be located together at one end of the main body or respectively at both ends of the main body. During the charge and discharge process of the battery, the positive active material and the negative active material react with the electrolyte, and the tabs connect the electrode terminals to form a current loop. The tab may be the first tab or the second tab described below.

[0122] According to some embodiments of the present application, as shown in Figures 3 to 6, the battery cell 1 described in the battery cell embodiment of the present application includes an electrode assembly 20, a shell 40, an end cover assembly 30 and a current collecting component 10. The electrode assembly 20 includes a first pole tab 21. The shell 40 is used to accommodate the electrode assembly 20, and the shell 40 has an opening 41. The end cover assembly 30 covers the opening 41 and is provided with an electrode lead-out portion 31. The current collecting component 10 includes a pole tab connection area 110 and an end cover connection area 130. The pole tab connection area 110 is used to connect to the first pole tab 21. The end cover connection area 130 is welded to the inner side of the electrode lead-out portion 31 and forms a first weld 32. The penetration depth of the first weld 32 formed on the electrode lead-out portion 31 is less than or equal to the thickness of the electrode lead-out portion 31.

[0123] In this embodiment, the inner side of the electrode lead-out portion 31 refers to the side of the electrode lead-out portion 31 facing the interior of the housing 40 after the end cap assembly 30 is closed over the opening 41. The current collecting component 10 can be disposed between the end cap assembly 30 and the electrode assembly 20, and serves to form a current path between the end cap assembly 30 and the electrode assembly 20. The current collecting component 10 forms a current path with the electrode assembly 20 by connecting to the first electrode tab 21 at the tab connection region 110. The current collecting component 10 forms a current path with the end cap assembly 30 by welding the end cap connection region 130 to the electrode lead-out portion 31. The tab connection region 110 and the end cap connection region 130 can be interconnected to form a current path. During the charge and discharge process of the battery cell 1, current can flow from the electrode assembly 20 through the tab connection region 110 and the end cap connection region 130 to the end cap assembly 30, or from the end cap assembly 30 through the end cap connection region 130 and the tab connection region 110 to the electrode assembly 20.

[0124] The formation of the first weld 32 in the end cap connection area 130 means that the welding process between the end cap assembly 30 and the current collecting component 10 involves melting the end cap connection area 130 from one side of the current collecting component 10 and extending the melt to the interior of the electrode lead-out portion 31, thereby forming the first weld 32 within the electrode lead-out portion 31. The penetration depth of the first weld 32 formed on the electrode lead-out portion 31 is less than or equal to the thickness of the electrode lead-out portion 31. This avoids cold welds or excessive penetration that can occur when welding the current collecting component 10 to the end cap assembly 30 from the outside of the end cap assembly 30 in conventional assembly methods. Furthermore, when the penetration depth of the first weld 32 on the electrode lead-out portion 31 is set to be less than the thickness of the electrode lead-out portion 31, cracks at the weld between the two are less likely to extend to the outer surface of the electrode lead-out portion 31, effectively preventing leakage of the electrolyte, thereby reducing the defective rate during the production process of the battery cell 1 and improving the quality of the battery cell 1. The cracks are mainly caused by the thermal expansion of the end cover assembly 30 and the current collecting component 10 during the welding process, and the stress generated after cooling after welding.

[0125] According to some embodiments of the present application, the first weld 32 may optionally have a penetration depth on the electrode lead-out portion 31 ranging from 1 / 4 to 3 / 4 of the thickness of the electrode lead-out portion 31. This ensures sufficient connection strength between the electrode lead-out portion 31 and the current collecting component 10 while leaving a margin for the electrode lead-out portion 31, thereby reducing the risk of cracks extending to the outer surface of the end cap assembly 30.

[0126] According to some embodiments of the present application, optionally, the matrix material of the electrode lead-out portion 31 is different from the matrix material of the current collecting component 10 , and / or the melting point of the matrix material of the electrode lead-out portion 31 is greater than the melting point of the matrix material of the current collecting component 10 .

[0127] Specifically, as shown in FIG6 , the base material of the electrode lead-out portion 31 may refer to the material of the base 311 of the electrode lead-out portion 31, and the base material of the current collecting component 10 may refer to the material of the base 101 of the current collecting component 10. The base refers to the component that forms the basic shape of the relevant components and primarily provides structural strength. A soldering layer or other material layers that play other auxiliary roles may be further formed on the base.

[0128] Through the above approach, different base materials can be used to meet the structural characteristics of the electrode lead portion 31 and the current collecting component 10. For example, the electrode lead portion 31 must meet a predetermined structural strength, while the current collecting component 10 must meet a certain degree of bendability. Furthermore, when welding the end cap connection area 130 to the electrode lead portion 31, the lower melting point of the base material of the current collecting component 10 helps lower the welding temperature, specifically the temperature at which the first weld 32 is formed. Meanwhile, the relatively higher melting point of the base material of the electrode lead portion 31 ensures that the electrode lead portion 31 is not easily welded through, thereby reducing the risk of leakage.

[0129] According to some embodiments of the present application, optionally, the thermal expansion coefficient of the base material of the electrode lead-out portion 31 is smaller than the thermal expansion coefficient of the base material of the current collecting component 10 .

[0130] The coefficient of thermal expansion (CTE) is the change in length per unit temperature change under constant pressure (p). When the CTE is positive, the welded portion of the electrode lead 31 expands due to the rising temperature during welding, causing stress, strain, and cracks. Using a base material with a low CTE for the electrode lead 31 helps minimize stress, strain, and cracks, thereby reducing the risk of leakage.

[0131] According to some embodiments of the present application, optionally, the base material of the electrode lead-out portion 31 is steel, and the base material of the current collecting component 10 is copper or aluminum.

[0132] The steel base material of the electrode lead-out portion 31 reduces the thermal expansion coefficient of the base 311 of the electrode lead-out portion 31 and provides good mechanical strength. Copper or aluminum has a lower melting point than steel, making the base material of the current collecting component 10 easier to weld. Furthermore, copper or aluminum has excellent electrical conductivity and a soft texture, making it easy to process and shape, making it suitable for the production of the current collecting component 10.

[0133] According to some embodiments of the present application, as shown in FIG6 , optionally, a soldering layer 312 is provided on the surface of the electrode lead-out portion 31 and / or a soldering layer 102 is provided on the surface of the current collecting component 10 .

[0134] During the welding process, the soldering layer 312 and / or the soldering layer 102 can help and promote the welding process, and also have a protective effect, prevent oxidation reaction, and reduce welding defects. By providing the soldering layer, the welding effect between the current collecting component 10 and the electrode lead portion 31 is improved.

[0135] The material of the soldering layer 312 and / or the soldering layer 102 may be, for example, rosin or a nickel / tin plated layer, etc. Optionally, the soldering layer 312 and / or the soldering layer 102 may be made by an electroplating process.

[0136] Optionally, the thickness of solder paste layer 312 and / or solder paste layer 102 is designed to be greater than or equal to 1 μm (micrometer) and less than or equal to 3 μm.

[0137] Furthermore, the current collecting component 10 includes a base 101 , and the soldering layer 102 may be provided on the inner side surface and the outer side surface of the base 101 of the current collecting component 10 .

[0138] According to some embodiments of the present application, optionally, the electrode lead portion 31 includes a base 311 , the soldering layer 312 is disposed on the base 311 , and at least a portion of the first welding portion 32 is located within the base 311 .

[0139] In this manner, the first weld portion 32 can penetrate the soldering layer 312 and further extend into the base 311. The provision of the soldering layer 312 is beneficial for improving the welding effect of the electrode lead portion 31. Furthermore, since the base 311 provides structural support and high structural strength, the first weld portion 32 extends into the base 311, which is beneficial for improving the connection strength.

[0140] According to some embodiments of the present application, the first weld 32 is optionally configured not to penetrate the substrate 311. Since the substrate 311 can provide structural support and has high structural strength, the first weld 32 does not penetrate the substrate 311, which can further reduce the risk of leakage.

[0141] According to some embodiments of the present application, the soldering layer 102 and / or the soldering layer 312 optionally include at least one of nickel or tin. When the substrate 101 and / or the substrate 311 are difficult to weld, disposing nickel or tin on the surface of the substrate 101 and / or the substrate 311 can improve the weldability of the electrode lead portion 31 and / or the current collecting component 10, thereby enhancing the welding effect. Furthermore, nickel or tin is conductive and does not affect the current connection between the electrode lead portion 31 and the current collecting component 10 after welding.

[0142] According to some embodiments of the present application, optionally, the first welding portion 32 is formed from a side of the end cap connection region 130 away from the electrode lead-out portion 31 and extends into the electrode lead-out portion 31 .

[0143] Specifically, the welding operation is performed from the side of the end cap connection area 130 facing away from the electrode lead portion 31, forming a first weld portion 32 that penetrates the end cap connection area 130 and further extends into the electrode lead portion 31. Performing welding from the side of the end cap connection area 130 facing away from the electrode lead portion 31 facilitates the welding operation and makes it less likely that the electrode lead portion 31 will be penetrated.

[0144] According to some embodiments of the present application, as shown in FIG7 , optionally, the tab connection region 110 is welded to the first tab 21 and forms a second weld portion 33 , which is formed from a side of the tab connection region 110 away from the first tab 21 and extends into the first tab 21 .

[0145] Specifically, the welding process can be performed from the side of the tab connection area 110 away from the first tab 21, forming a second weld portion 33 that penetrates the tab connection area 110 and further extends into the first tab 21. Welding is performed from the side of the tab connection area 110 away from the first tab 21 to facilitate the execution of the welding operation.

[0146] According to some embodiments of the present application, as further shown in Figures 8-9, optionally, the current collecting component 10 further includes a transition region 120 connected between the tab connection region 110 and the end cap connection region 130. The transition region 120 is configured to bend relative to the end cap connection region 130, and the tab connection region 110 is configured to bend relative to the transition region 120.

[0147] Through the above-described method, the transition region 120 can provide assembly redundancy for the tab connection region 110 and the end cap connection region 130. Specifically, by bending the transition region 120 relative to each other, the positional relationship between the tab connection region 110 and the end cap connection region 130 can be adjusted. This also allows the positional relationship between the end cap assembly 30 and the electrode assembly 20 to be adjusted, facilitating welding and assembly. For example, as described below, the end cap assembly 30 can be switched between a flattened state, a bent state, and an unfolded state according to different assembly processes.

[0148] According to some embodiments of the present application, optionally, as shown in Figures 3-4 and 8-9, the current collecting component 10, when laid flat, has a first reference direction D1 and a second reference direction D2 arranged along the main surface of the current collecting component 10 and perpendicular to each other. The tab connection area 110, the transition area 120, and the end cap connection area 130 are arranged sequentially along the first reference direction D1. The first main surface 171 of the end cap connection area 130 is in contact with the electrode lead portion 31 and is welded to the electrode lead portion 31 via a first weld portion 32 formed from the second main surface 172 of the end cap connection area 130. In this way, the connection area between the electrode lead portion 31 and the end cap connection area 130 can be increased, facilitating the welding operation.

[0149] According to some embodiments of the present application, the second major surface 174 of the tab connection region 110 is optionally in contact with the first tab 21 and welded to the first tab 21 via a second weld portion 33 formed from the first major surface 173 of the tab connection region 110. The first major surface 173 of the tab connection region 110 and the first major surface 171 of the end cap connection region 130 are located on the same side of the current collecting component 10. This facilitates welding operations during assembly, improving assembly efficiency.

[0150] Specifically, the electrode lead portion 31 and the first electrode tab 21 can be welded to the current collecting component 10 on either side thereof. The welding process penetrates the current collecting component 10. This arrangement facilitates the welding operation and reduces the risk of welding through the electrode lead portion 31, thereby reducing the risk of leakage. Furthermore, for the battery cell 1, the first weld portion 32 and the second weld portion 33 are located internally, preventing them from being exposed on the surface of the battery cell 1 and improving the aesthetics of the battery cell 1.

[0151] Optionally, the current collecting component 10 is formed from a sheet by stamping or other processing methods, and the "flattened state" mentioned above may mean that the main surfaces of at least one side of the above-mentioned parts of the current collecting component 10 are coplanar with each other.

[0152] Optionally, the "flat state" mentioned above may also mean that in the thickness direction of the above-mentioned parts of the current collecting component 10, the above-mentioned parts of the current collecting component 10 are located in the same reference plane, and at this time the first reference direction D1 and the second reference direction D2 are two reference directions located in the above-mentioned reference plane.

[0153] Optionally, the tab connection region 110 , the transition region 120 and the end cap connection region 130 are all of uniform thickness, and the thicknesses of the three are consistent.

[0154] According to some embodiments of the present application, optionally, as shown in FIG3 , after the battery cell 1 is assembled, the current collecting component 10 is in an expanded state between the electrode assembly 20 and the end cap assembly 30. In the expanded state, the tab connection area 110, the transition area 120, and the end cap connection area 130 are arranged non-overlappingly along the axial direction D3 of the battery cell 1. The axial direction D3 of the battery cell 1 also refers to the covering direction of the end cap assembly 30 relative to the housing 40.

[0155] By the above method, the battery cells 1 can be arranged in a single layer in the vertical direction along the axial direction D3 , which can reduce the size occupied by the current collecting component 10 along the axial direction D3 of the battery cells 1 , thereby improving the space utilization of the battery cells 1 .

[0156] According to some embodiments of the present application, optionally, as shown in Figures 4 and 8, the current collecting component 10 is configured to be in a bent state during the assembly process of the battery cell 1, so that after one of the first welding portion 32 and the second welding portion 33 is formed, a clearance is formed between the end cover assembly 30 and the electrode assembly 20, thereby allowing the formation of the other of the first welding portion 32 and the second welding portion 33.

[0157] Specifically, after the first weld 32 is formed, if the current collecting component 10 remains flat, the end cap assembly 30 will block the first major surface 173 of the tab connection area 110, making it difficult to form the second weld 33 on the first major surface 173 of the tab connection area 110 by welding. If the current collecting component 10 is bent, the end cap assembly 30 and the first major surface 173 of the tab connection area 110 are offset, facilitating welding between the tab connection area 110 and the electrode assembly 20.

[0158] Similarly, after the second weld 33 is formed, if the current collecting component 10 is flat, the electrode assembly 20 will block the second major surface 172 of the end cap connection area 130, making it difficult to weld the first weld 32 there. If the current collecting component 10 is bent, the electrode assembly 20 and the second major surface 172 of the end cap connection area 130 will avoid each other, facilitating welding between the end cap connection area 130 and the end cap assembly 30.

[0159] According to some embodiments of the present application, optionally, in the bent state, a clearance is formed between the end cap assembly 30 and the first main surface 173 of the tab connection area 110. This allows the end cap assembly 30 and the current collecting component 10 to be pre-assembled into an assembly 4 as shown in FIG8 , and then the tab connection area 110 and the electrode assembly 20 are welded, thereby improving assembly efficiency.

[0160] According to some embodiments of the present application, optionally, as shown in Figures 9-11, the end cover connection area 130 includes a first sub-end cover connection area 131 and a second sub-end cover connection area 132, the first sub-end cover connection area 131 is connected to the pole tab connection area 110, the second sub-end cover connection area 132 is connected to the first sub-end cover connection area 131, and a gap is maintained with the pole tab connection area 110, and the first sub-end cover connection area 131 and the second sub-end cover connection area 132 are respectively welded to the electrode lead-out portion 31 through the first welding portion 32.

[0161] By the above method, the welding area between the end cover connection area 130 and the end cover assembly 30 can be increased, which is conducive to maintaining a stable connection between the current collecting component 10 and the end cover assembly 30 and meeting the flow requirements between the end cover assembly 30 and the current collecting component 10.

[0162] Specifically, as shown in Figure 9, the second sub-end cap connection area 132 is connected to the tab connection area 110 via the first sub-end cap connection area 131, and the weld bead 136 is a path on the current collecting component 10 for welding to form the first fusion portion 32. Compared to providing only the first sub-end cap connection area 131, providing the second sub-end cap connection area 132 connected to the first sub-end cap connection area 131 can increase the length of the weld bead 136 of the end cap connection area 130, thereby increasing the connection area between the end cap connection area 130 and the end cap assembly 30, which is conducive to maintaining a stable connection between the current collecting component 10 and the end cap assembly 30, while also ensuring the flow requirements between the current collecting component 10 and the end cap assembly 30.

[0163] Furthermore, a certain gap is maintained between the second sub-end cap connection area 132 and the tab connection area 110, so that the bending between the first sub-end cap connection area 131 and the tab connection area 110 is not restricted by the second sub-end cap connection area 132, thereby achieving the effective avoidance described above. It is worth noting that the second sub-end cap connection area 132 is not limited to the form shown in the drawings of this application.

[0164] According to some embodiments of the present application, the current collecting component 10 optionally further includes a transition region 120 disposed between the first sub-end cap connection region 131 and the tab connection region 110. When laid flat, the current collecting component 10 has a first reference direction D1 and a second reference direction D2 perpendicular to each other, extending along the main surface of the current collecting component 10. The tab connection region 110, the transition region 120, and the first sub-end cap connection region 131 are sequentially arranged along the first reference direction D1. The second sub-end cap connection region 132 is located outside the transition region 120 along at least the second reference direction D2 and extends toward the tab connection region 110. A certain gap is maintained between the second sub-end cap connection region 132, the transition region 120, and the tab connection region 110. This arrangement increases the connection area between the end cap connection region 130 and the end cap assembly 30, while improving space utilization. Furthermore, the second sub-end cap connection region 132 does not interfere with the tab connection region 110.

[0165] Specifically, due to the size constraints of the battery cell 1, the dimensions of the current collecting component 10 in the axial direction D3 perpendicular to the battery cell 1 must be within a certain range to ensure that the current collecting component 10 is accommodated within the space provided by the housing 40. The second sub-end cap connection area 132 is located outside the transition area 120 along at least the second reference direction D2 and extends toward the tab connection area 110. This ensures that the end cap connection area 130 and the end cap assembly 30 have sufficient connection area while fully utilizing the dimensional space provided by the battery cell 1 for the current collecting component 10.

[0166] A certain gap is maintained between the second sub-end cap connection area 132 and the transition area 120 and the tab connection area 110. That is, the second sub-end cap connection area 132 is not directly connected to the transition area 120 and the tab connection area 110, but is connected to the transition area 120 through the first sub-end cap connection area 131, and further connected to the tab connection area 110 through the first sub-end cap connection area 131 and the transition area 120. Furthermore, as described above, the bending between the first sub-end cap connection area 131, the transition area 120, and the tab connection area 110 will not be restricted by the second sub-end cap connection area 132, thereby enabling effective avoidance. In addition, a certain gap is maintained between the second sub-end cap connection area 132 and the transition area 120 and the tab connection area 110, which is conducive to the infiltration of the electrolyte in the electrode assembly 20.

[0167] Optionally, the weld bead 136 of the end cap connection area 130 matches the shape of the end cap connection area 130 .

[0168] According to some embodiments of the present application, optionally, as shown in FIG. 10 , the second sub-end cover connection region 132 is further extended to be located outside the tab connection region 110 along the second reference direction D2 .

[0169] By adopting the above-mentioned method, the connection area between the end cover connection region 130 and the end cover assembly 30 can be further increased, and the space utilization rate can be improved at the same time.

[0170] According to some embodiments of the present application, optionally, the number of the second sub-end cover connection area 132 is one, and both ends of the second sub-end cover connection area 132 are respectively connected to the first sub-end cover connection area 131 and are arranged around the transition area 120 and the tab connection area 110.

[0171] In the above manner, the second sub-end cover connection area 132 and the first sub-end cover connection area 131 can form a closed loop, so that the length of the weld 136 can be maximized while meeting the space conditions provided by the shell 40, thereby further increasing the connection area between the end cover connection area 130 and the end cover assembly 30, while improving space utilization.

[0172] It is worth noting that the second sub-end cover connection area 132 further extends to be located outside the tab connection area 110 along the second reference direction D2 and is not limited to the closed loop form shown in FIG. 10 . The second sub-end cover connection area 132 may also be open.

[0173] According to some embodiments of the present application, as shown in FIG. 9 , optionally, there are two second sub-end cover connection regions 132 , which are respectively located on opposite sides of the transition region 120 along the second reference direction D2 .

[0174] Specifically, one end of each second sub-end cap connection region 132 is connected to the first sub-end cap connection region 131 and extends toward the tab connection region 110. The other end of the second sub-end cap connection region 132 can be located outside the transition region 120 or outside the tab connection region 110. This improves the balance and stability of the connection between the current collecting component 10 and the end cap assembly 30.

[0175] According to some embodiments of the present application, optionally, the tab connection area 110 and the first sub-end cap connection area 131 are respectively arranged in a circular segment shape. In this way, the tab connection area 110 and the first sub-end cap connection area 131 are more easily adapted to the arc-shaped edges of the shell 40 and / or the end cap assembly 30. In particular, when the battery cell 1 is configured to be cylindrical or nearly cylindrical, the above-mentioned configuration can make full use of the space provided by the shell 40. Furthermore, the straight edge of the circular segment shape can ensure that there is sufficient flow width between the tab connection area 110 and the first sub-end cap connection area 131, ensuring the flow requirement between the tab connection area 110 and the end cap connection area 130.

[0176] According to some embodiments of the present application, optionally, when the current collecting component 10 is laid flat, the outer edge 111 of the tab connection area 110 and the outer edge 133 of the first sub-end cover connection area 131 are respectively arranged in an arc shape and are arranged with a common center O. In this way, the outer edge 133 of the first sub-end cover connection area 131 and the outer edge 111 of the tab connection area 110 are arranged in a concentric arc shape, which can reduce the processing difficulty of the current collecting component 10, facilitate the processing and forming of the current collecting component 10, and make it easier to adapt to cylindrical or nearly cylindrical battery cells 1.

[0177] Optionally, the center O of the outer edge 111 of the tab connection area 110 falls on the central axis of the battery cell 1 or the electrode assembly 20 .

[0178] According to some embodiments of the present application, as shown in Figures 9 and 10, optionally, in the flat state of the current collecting component 10, the outer edge 111 of the tab connection area 110 is arranged in an arc shape, and there is an angle θ between the first sub-end cover connection area 131 and the line connecting the two outermost connection points P1 and P2 of the transition area 120 along the second reference direction D2 to the center O of the outer edge 111 of the tab connection area 110, and the angle θ is smaller than the central angle α of the outer edge 111 of the tab connection area 110.

[0179] Through the above-described method, the area of ​​the tab connection region 110 that can connect with the first tab 21 can be ensured, thereby meeting the overcurrent requirements. Specifically, because the end cap connection region 130 increases the connection area with the end cap assembly 30 through the additional provision of the second sub-end cap connection region 132, the first sub-end cap connection region 131 can be appropriately reduced to ensure the connection area between the tab connection region 110 and the first tab 21, thereby ensuring the overcurrent requirements between the tab connection region 110 and the electrode assembly 20.

[0180] Optionally, the sum of the included angle θ and the central angle α is less than 360 degrees.

[0181] According to some embodiments of the present application, optionally, the center angle α of the outer edge 111 of the tab connection area 110 is 120-240 degrees, and the included angle θ is 80-120 degrees. For example, the center angle α can be set to 180 degrees, and the included angle θ can be 120 degrees or 150 degrees. For another example, the center angle α can be set to 150 degrees, and the included angle θ can be 90 degrees or 120 degrees. In this way, it is possible to simultaneously ensure the area of ​​the tab connection area 110 that can be connected to the first tab 21 and the area of ​​the end cap connection area 130 that can be connected to the electrode lead portion 31.

[0182] According to some embodiments of the present application, optionally, when the current collecting component 10 is laid flat, the outer edge 133 of the first sub-end cap connection area 131 and the outer edge 134 of the second sub-end cap connection area 132 are each arranged in an arc shape, and are arranged with a common center O and equal radius. This facilitates the processing and forming of the current collecting component 10 and makes it easier to adapt to cylindrical battery cells 1 or nearly cylindrical battery cells 1.

[0183] In some embodiments, as shown in Figure 10, the outer edge 133 of the first sub-end cover connection area 131 and the outer edge 134 of the second sub-end cover connection area 132 can form a complete circle. In other embodiments, as shown in Figure 9, the outer edge 133 of the first sub-end cover connection area 131 and the outer edge 134 of the second sub-end cover connection area 132 can form an arc.

[0184] According to some embodiments of the present application, optionally, when the current collecting component 10 is laid flat, the outer edge 134 of the second sub-end cap connection area 132 and the inner edge 135 of the second sub-end cap connection area 132 are arranged in an arc shape and are arranged with a common center O. The ratio between the radius of the outer edge 134 of the second sub-end cap connection area 132 and the radius of the inner edge 135 of the second sub-end cap connection area 132 is 1.1-1.3. In this way, the connection area between the second sub-end cap connection area 132 and the electrode lead portion 31 can be increased, while ensuring the flow rate requirement between the end cap connection area 130 and the tab connection area 110. Specifically, since the second sub-end cover connection area 132 is located on the outside of the transition area 120, the two are complementary settings. If the width of the second sub-end cover connection area 132 is too small, the connection area between the second sub-end cover connection area 132 and the electrode lead-out portion 31 cannot be ensured, and even effective welding cannot be achieved. If the width of the second sub-end cover connection area 132 is too large, the width of the transition area 120 becomes smaller accordingly, so that the transition area 120 cannot meet the overcurrent requirements between the end cover connection area 130 and the tab connection area 110.

[0185] Furthermore, because the inner edge 135 of the second sub-end cap connection region 132 is arranged in an arc shape and is co-centered O with the outer edge 134 of the second sub-end cap connection region 132, the radial width of the second sub-end cap connection region 132 can be maintained consistent, thereby improving the structural uniformity of the current collecting component 10. In particular, when the second sub-end cap connection region 132 surrounds the tab connection region 110 and is spaced apart from the tab connection region 110, the radial gap between the inner edge 135 of the second sub-end cap connection region 132 and the outer edge 111 of the tab connection region 110 can be made equal, further improving the structural uniformity of the current collecting component 10.

[0186] Optionally, the ratio of the radius of the outer edge 134 of the second sub-end cap connection area 132 to the radius of the inner edge 135 of the second sub-end cap connection area 132 may be 1.15, 1.2, or 1.25.

[0187] According to some embodiments of the present application, as shown in FIG9 , optionally, when the current collecting component 10 is laid flat, the outer edge 133 of the first sub-end cover connection region 131 and the outer edge 121 of the transition region 120 are each arranged in an arc shape and are arranged co-centered O. This approach can reduce the difficulty of processing the current collecting component 10 and facilitate the processing and forming of the current collecting component 10.

[0188] Furthermore, the outer edge 121 of the transition region 120 and the outer edge 111 of the tab connection region 110 share a common center O. In some embodiments, the outer edge 121 of the transition region 120 and the outer edge 111 of the tab connection region 110 have the same radius and can therefore be connected to form an arc.

[0189] According to some embodiments of the present application, as shown in FIG11 , optionally, when the current collecting component 10 is laid flat, the outer edge 111 of the tab connection region 110 is arranged in an arc shape. The current collecting component 10 further comprises a reference circle 140 having a radius extending from a line connecting the outermost connection points P1 or P2 between the first sub-end cap connection region 131 and the transition region 120 along the second reference direction D2 to the center O of the outer edge 111 of the tab connection region 110. The outer edge 121 of the transition region 120 is located within the reference circle 140 and spaced apart from the reference circle 140. In this manner, sufficient hollow space is formed between the transition region 120 and the second sub-end cap connection region 132, thereby reducing the material usage of the current collecting component 10 and improving the wetting effect of the electrolyte on the electrode assembly 20.

[0190] Optionally, one end of the outer edge 121 of the transition zone 120 is located on the circumference of the reference circle 140 , and the other end of the outer edge 121 of the transition zone 120 is located within the circumference of the reference circle 140 , so that the outer edge 121 of the transition zone 120 is spaced apart from the reference circle 140 .

[0191] According to some embodiments of the present application, optionally, a spacing width d3 between the outer edge 121 of the transition region 120 and the reference circle 140 along the second reference direction D2 gradually widens in a direction from the first sub-end cover connection region 131 to the tab connection region 110 .

[0192] Specifically, the closer the outer edge 121 of the transition region 120 is to the first sub-end cap connection region 131, the smaller the width d3 of the gap between the transition region 120 and the reference circle 140 along the second reference direction D2. The closer the outer edge 121 of the transition region 120 is to the tab connection region 110, the larger the width d3 of the gap between the transition region 120 and the reference circle 140 along the second reference direction D2. This approach creates a sufficient hollow space between the transition region 120 and the second sub-end cap connection region 132, thereby reducing the material usage of the current collecting component 10 and improving the wetting effect of the electrolyte on the electrode assembly 20.

[0193] According to some embodiments of the present application, optionally, the transition region 120 is arranged in a trapezoidal shape, and the width of the transition region 120 along the second reference direction D2 gradually widens in the direction from the first sub-end cover connection region 131 to the tab connection region 110 .

[0194] Specifically, the width of the transition region 120 along the second reference direction D2 is greatest at the junction of the transition region 120 and the tab connection region 110, and is smallest at the junction of the transition region 120 and the first sub-end cap connection region 131. This approach creates a sufficient hollow space between the transition region 120 and the second sub-end cap connection region 132, thereby reducing the material consumption of the current collecting component 10 and improving the electrolyte's wetting effect on the electrode assembly 20. Furthermore, the trapezoidal shape of the transition region 120 facilitates the processing and forming of the current collecting component 10.

[0195] It is worth noting that, when the included angle θ is smaller than the central angle α, the above arrangement can form a sufficient hollow space while ensuring the flow requirement of the transition zone 120 .

[0196] According to some embodiments of the present application, as shown in Figures 9 and 11, optionally, when the current collecting component 10 is laid flat, when the outer edge 111 of the tab connection area 110 is projected along the first reference direction D1 toward the end cap connection area 130, the projections of the outermost points P3 and P4 of the outer edge 111 of the tab connection area 110 in the second reference direction D2 are located outside the inner edge 135 of the second sub-end cap connection area 132. In this way, the area of ​​the tab connection area 110 that can connect with the first tab 21 can be ensured, thereby meeting the overflow requirements.

[0197] According to some embodiments of the present application, optionally, the outer edge 111 of the tab connection area 110 and the inner edge 135 of the second sub-end cover connection area 132 are respectively arranged in an arc shape and have a common center O with each other, and the radius of the outer edge 111 of the tab connection area 110 is greater than the radius of the inner edge 135 of the second sub-end cover connection area 132.

[0198] By this method, the area of ​​the tab connection region 110 that can connect with the first tab 21 can be ensured, while facilitating the processing and forming of the current collecting component 10. Furthermore, it is easier to adapt to cylindrical or nearly cylindrical battery cells 1.

[0199] According to some embodiments of the present application, the current collecting component 10 may optionally be provided with a first trace line 150 and a second trace line 151 along the second reference direction D2. The first trace line 150 is configured to allow the tab connection area 110 to bend relative to the transition area 120 along the first trace line 150, and the second trace line 151 is configured to allow the first sub-end cap connection area 131 to bend relative to the transition area 120 along the second trace line 151. This facilitates bending of the current collecting component 10. According to some embodiments of the present application, as shown in Figures 9-11, in the flattened state, the first trace line 150 and the second trace line 151 may have a first distance d1 between them along the first reference direction D1, and the second trace line 151 may have a second distance d2 from the outer edge 133 of the first sub-end cap connection area 131 along the first reference direction D1. The first distance d1 is greater than the maximum value of the second distance d2, so that in the bent state, the outer edge 34 of the end cap assembly 30 maintains a predetermined distance from the plane of the first major surface 173 of the tab connection area 110. By adopting the above-mentioned method, the current collecting component 10 can be bent easily, while interference between the end cap assembly 30 and the electrode assembly 20 can be avoided, thereby facilitating the welding operation.

[0200] Since the two sides of the current collecting component 10 are respectively connected to the first pole ear 21 and the end cover assembly 30, and the first pole ear 21 is generally arranged on the end face of the electrode assembly 20, in order to achieve the welding method shown in Figure 8, the current collecting component 10 needs to be bent at least twice. By setting the first distance d1 to be greater than the maximum value of the second distance d2, the end cover assembly 30 can be made sufficiently away from the pole ear connection area 110, while avoiding interference with the end face of the electrode assembly 20, thereby facilitating the welding operation.

[0201] Optionally, the end cap connection area 130 is bent perpendicular to the tab connection area 110 , and the outer edge 34 of the end cap assembly 30 maintains a predetermined distance from the plane where the tab connection area 110 is located, thereby avoiding interference between the end cap assembly 30 and the end face of the electrode assembly 20 .

[0202] Specifically, in FIG8 , the tab connection region 110 and the transition region 120 are arranged at an obtuse angle, while the transition region 120 and the end cap connection region 130 are arranged at an acute angle. In this case, the projection of the end cap connection region 130 and the end cap assembly 30 connected thereto along the vertical direction of the tab connection region 110 falls outside the tab connection region 110, effectively avoiding obstruction of the tab connection region 110. According to some embodiments of the present application, optionally, the ratio of the minimum flow area S of the transition region 120 to the battery capacity C of the battery cell 1 is greater than or equal to 0.15 mm2 / Ah. The minimum flow area of ​​the transition region 120 is the product of the minimum width of the transition region 120 along the second reference direction D2 and the thickness of the transition region 120. For example, S / C may be 0.18 mm2 / Ah, 0.20 mm2 / Ah, or 0.25 mm2 / Ah. In the above manner, the current flow capacity of the transition zone 120 can meet the current transmission requirements of the electrode assembly 20 and the end cover assembly 30.

[0203] According to some embodiments of the present application, optionally, the electrode assembly 20 includes an electrode body arranged in a cylindrical shape, the outer edge 111 of the tab connection area 110 is arranged in an arc shape, and the ratio of the radius of the outer edge 111 of the tab connection area 110 to the radius of the electrode assembly 20 is greater than or equal to 0.8.

[0204] For example, the ratio of the radius of the outer edge 111 of the tab connection region 110 to the radius of the electrode assembly 20 can be 0.8-0.85 or 0.85-0.9. Furthermore, the ratio of the radius of the outer edge 111 of the tab connection region 110 to the radius of the electrode assembly 20 is greater than or equal to 0.9. In this way, the area of ​​the tab connection region 110 that can connect with the first tab 21 can be ensured, thereby meeting the overcurrent requirements.

[0205] According to some embodiments of the present application, optionally, as shown in FIG11 , the current collecting component 10 is further provided with a hollow portion 160 . In this way, providing the hollow portion 160 can reduce the material usage of the current collecting component 10 and improve the electrolyte infiltration effect in the electrode assembly 20 .

[0206] According to some embodiments of the present application, optionally, the outer edge 111 of the tab connection area 110 is arranged in an arc shape and the hollow portion 160 is located at the center O of the outer edge 111 of the tab connection area 110, or the hollow portion 160 is located entirely within the tab connection area 110.

[0207] In the above manner, the hollow portion 160 is located at the center O of the circle, which can further enhance the electrolyte's infiltration effect on the electrode assembly 20. The hollow portion 160 is located as a whole in the tab connection area 110, and the hollow portion can be used as an observation window to assist in positioning. Specifically, since the center O is generally aligned with the center hole formed by winding the electrode assembly 20, the hollow portion 160 is directly connected to the center hole, which can further enhance the electrolyte's infiltration effect on the electrode assembly 20. The tab connection area 110 needs to be fitted with the first tab 21, and then the hollow portion 160 is located as a whole in the tab connection area 110, making it easier to observe the alignment between the electrode assembly 20 and the current collecting component 10.

[0208] Furthermore, the actual width of the transition region 120 along the second reference direction D2 is greater than or equal to the width L1 at the connection location between the transition region 120 and the first sub-end cover connection region 131. At the location of the hollow portion 160, the actual width of the transition region 120 is equal to the distance L2 between the intersection points P5 and P6 of a reference line parallel to the second reference direction D2 and the two side edges of the transition region 120, minus the length L3 cut off by the hollow portion 160.

[0209] According to some embodiments of the present application, optionally, as shown in Figures 3, 4, and 12, the end cap assembly 30 includes an end cap 30a, and the electrode lead portion 31 includes at least a portion of the end cap 30a, and the end cap 30a covers the opening 41. In other embodiments, the electrode lead portion 31 may be an electrode terminal provided on the end cap 30a, and the electrode terminal protrudes from the end cap 30a.

[0210] According to some embodiments of the present application, as shown in Figure 12, optionally, the electrode lead-out portion 31 includes an annular boss 31a of the end cover 30a protruding toward the electrode assembly 20, the end cover connection area 130 is welded to the top surface of the annular boss 31a, and the outer edge 111 of the tab connection area 110 overlaps the top surface of the annular boss 31a.

[0211] By utilizing the annular boss 31a to support the tab connection area 110 in the aforementioned manner, deformation and displacement of the current collecting component 10 can be reduced, thereby improving the structural stability of the battery cell 1. Specifically, during use of the battery cell 1, gas or vibration may be generated within the battery cell 1, and the transition region 120 and the tab connection area 110 of the current collecting component 10 may be susceptible to deformation or displacement. The outer edge 111 of the tab connection area 110 overlaps the annular boss 31a, allowing the annular boss 31a to support the tab connection area 110 in a direction perpendicular to the tab connection area 110, thereby reducing deformation and displacement of the current collecting component 10.

[0212] According to some embodiments of the present application, the outer edge 111 of the tab connection area 110 is optionally configured in an arc shape, and the radius R1 of the outer edge 111 of the tab connection area 110 is greater than the inner edge radius R2 of the annular boss 31a and smaller than the outer edge radius R3 of the annular boss 31a. In this manner, while the annular boss 31a supports the tab connection area 110, interference between the outer edge of the tab connection area 110 and the housing 40 is avoided.

[0213] According to some embodiments of the present application, the housing 40 is optionally electrically connected to the end cap 30a. As further shown in FIG3 , the housing 40 includes a bottom wall 42 disposed opposite the end cap 30a, and an electrode terminal 43 is provided on the bottom wall 42, protruding from the bottom wall 42. The electrode assembly 20 also includes a second electrode tab 22 having a polarity opposite to that of the first electrode tab 21. The second electrode tab 22 is located on a side of the electrode assembly 20 facing the electrode terminal 43, and the second electrode tab 22 is electrically connected to the electrode terminal 43.

[0214] In this way, the shell 40 and the electrode terminals 43 provided on the bottom wall 42 of the shell 40 are used as the positive and negative electrodes of the battery cell 1, which can simplify the assembly complexity of the battery cell and facilitate the connection between the battery cell 1 and external equipment.

[0215] According to some embodiments of the present application, as shown in FIG2 , the battery 100 a described in the battery embodiment of the present application includes the above-mentioned battery cell 1 .

[0216] According to some embodiments of the present application, as shown in FIG1 , the electric device described in the electric device embodiment of the present application includes the above-mentioned battery 100 a.

[0217] According to some embodiments of the present application, as shown in FIG8 , the present application further provides an assembly assembly 4 pre-assembled from an end cap assembly 30 and a current collecting component 10. In assembly assembly 4, the current collecting component 10 can be configured to be pre-bent into a bent state and maintain the bent state in the absence of external forces, thereby simplifying the subsequent assembly process with the electrode assembly 20. The specific structures of the end cap assembly 30 and the current collecting component 10 have been described in detail above and will not be repeated here.

[0218] According to some embodiments of the present application, as shown in FIG13 , the assembly method of the battery cell 1 of the present application described in the first embodiment includes:

[0219] S100 : providing an assembly component 4 , wherein the current collecting component is in a bent state. In the bent state, a clearance is formed between the end cap assembly 30 and the first main surface 173 of the tab connection area 110 .

[0220] Specifically as shown in FIG8 , a clearance is formed between the end cap assembly 30 and the first main surface 173 of the tab connection area 110 , which is conducive to the next step of welding the tab connection area 110 to the first tab 21 from the first main surface 173 of the tab connection area 110 .

[0221] The assembly process of the assembly component 4 itself may include:

[0222] S110 : attaching the first main surface 171 of the end cap connection region 130 to the end cap assembly 30 .

[0223] S120: Welding the end cap connection area 130 to the end cap assembly 30 from the second main surface 172 of the end cap connection area 130. This can prevent the end cap assembly 30 from being welded through and can also prevent the nickel plating on the outer side of the end cap assembly 30 from being damaged and thus causing the risk of rust.

[0224] Optionally, ultrasonic welding is used for welding so that the welding teeth are located at the current collecting component 10, which can avoid the nickel plating layer of the end cover assembly 30 being damaged and thus causing the risk of rust.

[0225] Optionally, laser welding is used for welding so that the welding pool is located at the current collecting component 10, which can avoid the nickel plating layer of the end cover assembly 30 from being damaged and thus causing the risk of rust.

[0226] S130: Bend the current collecting component 10 to allow the end cap assembly 30 to make way for the tab connection area 110. The bending process of the current collecting component 10 can be performed before or after welding the current collecting component 10 and the end cap 30a.

[0227] S200 : Laminating the second main surface 174 of the tab connection region 110 to the first tab 21 of the electrode assembly 20 .

[0228] In this way, the positional relationship between the tab connection area 110 and the electrode assembly 20 can be determined before welding, facilitating the execution of the welding operation.

[0229] S300 : welding the tab connection region 110 to the first tab from the first major surface 173 of the tab connection region 110 .

[0230] Welding the current collecting component 10 and the end cover assembly 30 from the side of the current collecting component 10 can avoid the risks of cold welding and welding penetration caused by welding the current collecting component 10 and the end cover assembly 30 from the outside of the end cover assembly 30 in the conventional assembly method, which is beneficial to reducing the defective rate of the battery cell 1 production process and improving the quality of the battery cell 1.

[0231] Optionally, the tab connection region 110 is welded to the first tab 21 of the electrode assembly 20 from the first main surface 173 of the tab connection region 110 by ultrasonic welding.

[0232] Optionally, the tab connection region 110 is welded to the first tab 21 of the electrode assembly 20 from the first main surface 173 of the tab connection region 110 by laser welding.

[0233] According to some embodiments of the present application, optionally, the assembly method further includes:

[0234] S400: The end cover assembly 30 is placed on the opening 41 of the shell 40 accommodating the electrode assembly 20, so that the current collecting component 10 is arranged between the electrode assembly 20 and the end cover assembly 30, and unfolded into an unfolded state, wherein in the unfolded state, the tab connection area 110, the transition area 120 and the end cover connection area 130 are arranged non-overlappingly along the axial direction D3 of the battery cell 1.

[0235] The end cap assembly 30 is installed over the opening 41 of the housing 40 housing the electrode assembly 20 to prevent electrolyte leakage. The current collecting component 10 is installed synchronously with the end cap assembly 30. When the end cap assembly 30 is installed, the current collecting component 10 can be deployed to its expanded state. This arrangement improves the efficiency of the assembly 4.

[0236] According to some embodiments of the present application, as shown in FIG14 , another embodiment of the assembly method of the battery cell 1 of the present application describes an assembly method including:

[0237] S500: Provide an electrode assembly 20 , an end cap assembly 30 and a current collecting component 10 , wherein the electrode assembly 20 includes a first electrode tab 21 , the end cap assembly 30 is provided with an electrode lead-out portion 31 , and the current collecting component 10 includes a tab connection area 110 and an end cap connection area 130 .

[0238] S600: forming a first welding portion 32 for welding the end cap connection area 130 and the electrode lead-out portion 31 and a second welding portion 33 for welding the tab connection area 110 and the first tab 21 , wherein the penetration of the first welding portion 32 formed on the electrode lead-out portion 31 is less than the thickness of the electrode lead-out portion 31 .

[0239] The electrode assembly 20, current collecting component 10, and end cap assembly 30 are connected together by a first weld 32 and a second weld 33. The first weld 32 penetrates the end cap connection area 130 but does not penetrate the electrode lead-out portion 31 to prevent leakage. The second weld 33 can penetrate the tab connection area 110.

[0240] According to some embodiments of the present application, optionally, the steps of forming the first weld portion 32 for welding the end cap connection area 130 and the electrode lead portion 31 and the second weld portion 33 for welding the tab connection area 110 and the first tab 21 include:

[0241] S700: Bend the current collecting component 10 into a bent state so that after one of the first welding portion 32 and the second welding portion 33 is formed, an avoidance is formed between the end cap assembly 30 and the electrode assembly 20, thereby forming the other of the first welding portion 32 and the second welding portion 33.

[0242] The current collecting component 10 may be bent when both the first weld 32 and the second weld 33 are formed, or may be bent after one of the first weld 32 and the second weld 33 is formed. For example, the tab connection region 110 may be welded to the first tab 21 to form the second weld 33, and then the current collecting component 10 may be bent.

[0243] This arrangement makes welding operations easier and reduces the risk of leakage.

[0244] Welding the current collecting component 10 and the end cover assembly 30 from the side of the current collecting component 10 can avoid the risks of cold welding and welding penetration caused by welding the current collecting component 10 and the end cover assembly 30 from the outside of the end cover assembly 30 in the conventional assembly method, which is beneficial to reducing the defective rate of the battery cell 1 production process and improving the quality of the battery cell 1.

[0245] Optionally, the first weld portion 32 is formed from the side of the end cap connection region 130 away from the electrode lead portion 31, and the second weld portion 33 is formed from the side of the tab connection region 110 away from the first tab 21. In this way, the welding operation can be facilitated.

[0246] Optionally, the step of forming the first weld portion 32 for welding the end cap connection area 130 and the electrode lead portion 31 and the second weld portion 33 for welding the tab connection area 110 and the first tab 21 further includes:

[0247] S710: After the first welding portion 32 and the second welding portion 33 are formed, the end cap assembly 30 is placed on the opening 41 of the shell 40 accommodating the electrode assembly 20, and the current collecting component 10 is unfolded at the same time so that the end cap assembly 30 covers the current collecting component 10 and the electrode assembly 20.

[0248] To sum up, the embodiments of the present application can realize the welding of the current collecting component 10 and the end cover assembly 30 from the side of the current collecting component 10 and the welding of the current collecting component 10 and the first pole ear 21 from the side of the current collecting component 10, which can avoid the risks of cold welding and welding through caused by welding the end cover assembly 30 from the side of the end cover assembly 30 in the conventional assembly method, which is beneficial to reducing the defective rate of the battery cell 1 production process and improving the quality of the battery cell 1.

[0249] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery cell, characterized in that: include: An electrode assembly including a first electrode tab; a shell, for accommodating the electrode assembly, wherein the shell has an opening; an end cap assembly, covering the opening and provided with an electrode lead-out portion; The current collecting component includes a tab connection area and an end cover connection area, wherein the tab connection area is used to connect to the first tab, and the end cover connection area is welded to the inner side of the electrode lead-out portion to form a first fusion portion, and the depth of fusion formed by the first fusion portion on the electrode lead-out portion is less than or equal to the thickness of the electrode lead-out portion.

2. The battery cell according to claim 1, wherein: The penetration depth of the first weld portion formed on the electrode lead-out portion is between 1 / 4 and 3 / 4 of the thickness of the electrode lead-out portion.

3. The battery cell according to claim 1 or 2, characterized in that: The base material of the electrode lead-out portion is different from the base material of the current collecting component, and / or the melting point of the base material of the electrode lead-out portion is greater than the melting point of the base material of the current collecting component.

4. The battery cell according to any one of claims 1 to 3, characterized in that: The thermal expansion coefficient of the base material of the electrode lead-out portion is smaller than the thermal expansion coefficient of the base material of the current collecting component.

5. The battery cell according to any one of claims 1 to 4, characterized in that: The base material of the electrode lead-out portion is steel, and the base material of the current collecting component is copper or aluminum.

6. The battery cell according to any one of claims 1 to 5, characterized in that: A soldering layer is provided on the surface of the electrode lead-out portion and / or the current collecting component.

7. The battery cell according to claim 6, characterized in that The electrode lead-out portion includes a base, the soldering layer is arranged on the base, and at least a portion of the first welding portion is located in the base.

8. The battery cell according to claim 7, characterized in that The first weld portion is configured not to penetrate the substrate.

9. The battery cell according to any one of claims 6 to 8, characterized in that: The soldering layer includes at least one of nickel or tin.

10. The battery cell according to any one of claims 1 to 9, characterized in that: The first welding portion is formed from a side of the end cover connection region away from the electrode lead-out portion and extends into the electrode lead-out portion.

11. The battery cell according to any one of claims 1 to 10, characterized in that: The tab connection region is welded to the first tab to form a second weld portion. The second weld portion is formed from a side of the tab connection region away from the first tab and extends into the first tab.

12. The battery cell according to any one of claims 1 to 11, characterized in that: The current collecting component further includes a transition area connected between the tab connection area and the end cover connection area; The transition zone is configured to be able to be bent relative to the end cover connection zone, and the tab connection zone is configured to be able to be bent relative to the transition zone.

13. The battery cell according to claim 12, characterized in that: The current collecting component has a first reference direction and a second reference direction which are arranged along the main surface of the current collecting component and are perpendicular to each other in a flat state. The tab connection area, the transition area and the end cover connection area are arranged in sequence along the first reference direction. The first main surface of the end cover connection area is in contact with the electrode lead-out portion and is welded to the electrode lead-out portion through the first welding portion formed from the second main surface of the end cover connection area.

14. The battery cell according to claim 13, characterized in that The second main surface of the tab connection area is in contact with the first tab and is welded to the first tab through a second weld portion formed from the first main surface of the tab connection area, wherein the first main surface of the tab connection area and the first main surface of the end cap connection area are located on the same side of the current collecting component.

15. The battery cell according to any one of claims 12 to 14, characterized in that: After the battery cell is assembled, the current collecting component is in an expanded state between the electrode assembly and the end cover assembly. In the expanded state, the tab connection area, the transition area and the end cover connection area are non-overlappingly arranged along the axial direction of the battery cell.

16. The battery cell according to any one of claims 1 to 15, characterized in that: The tab connection area is welded to the first tab and forms a second weld portion. The current collecting component is configured to be in a bent state during the assembly process of the battery cell, so that after one of the first weld portion and the second weld portion is formed, a gap is formed between the end cover assembly and the electrode assembly, thereby allowing the formation of the other of the first weld portion and the second weld portion.

17. The battery cell according to claim 16, characterized in that In the bent state, a clearance is formed between the end cap assembly and the first main surface of the tab connection area.

18. The battery cell according to any one of claims 1 to 17, characterized in that: The end cover connection area includes a first sub-end cover connection area and a second sub-end cover connection area, the first sub-end cover connection area is connected to the pole tab connection area, the second sub-end cover connection area is connected to the first sub-end cover connection area, and a gap is maintained with the pole tab connection area, the first sub-end cover connection area and the second sub-end cover connection area are respectively welded to the electrode lead-out part through the first welding part.

19. The battery cell according to claim 18, characterized in that The current collecting component further includes a transition area arranged between the first sub-end cover connection area and the tab connection area. The current collecting component has a first reference direction and a second reference direction arranged along the main surface of the current collecting component and perpendicular to each other in a flat state. The tab connection area, the transition area and the first sub-end cover connection area are arranged in sequence along the first reference direction. The second sub-end cover connection area is located outside the transition area at least along the second reference direction and extends toward the tab connection area. A certain gap is maintained between the second sub-end cover connection area and the transition area and the tab connection area.

20. The battery cell according to claim 19, characterized in that The second sub-end cover connection region further extends to be located outside the tab connection region along the second reference direction.

21. The battery cell according to claim 20, characterized in that The number of the second sub-end cover connection area is one, and both ends of the second sub-end cover connection area are respectively connected to the first sub-end cover connection area, and are arranged around the transition area and the tab connection area.

22. The battery cell according to claim 19 or 20, characterized in that: There are two second sub-end cover connection areas, which are located at least on two opposite sides of the transition area along the second reference direction.

23. The battery cell according to any one of claims 18 to 22, characterized in that: The tab connection area and the first sub-end cover connection area are respectively arranged in a circular segment shape.

24. The battery cell according to claim 23, characterized in that When the current collecting component is laid flat, the outer edge of the tab connection area and the outer edge of the first sub-end cover connection area are respectively arranged in an arc shape and are arranged cocentrically with each other.

25. The battery cell according to any one of claims 19 to 24, characterized in that: When the current collecting component is in a flat state, the outer edge of the tab connection area is arranged in an arc shape, and there is an angle between the first sub-end cover connection area and the line connecting the two outermost connection points of the transition area along the second reference direction to the center of the outer edge of the tab connection area, and the angle is smaller than the central angle of the outer edge of the tab connection area.

26. The battery cell according to claim 25, characterized in that The central angle of the outer edge of the tab connection area is 120-240 degrees, and the included angle is 80-120 degrees.

27. The battery cell according to any one of claims 18 to 26, characterized in that: When the current collecting component is laid flat, outer edges of the first sub-end cover connection area and the second sub-end cover connection area are respectively arranged in an arc shape, and are cocentric and have the same radius.

28. The battery cell according to any one of claims 18 to 27, characterized in that: When the current collecting component is in a flat state, the outer edge of the second sub-end cover connection area and the inner edge of the second sub-end cover connection area are arranged in an arc shape and are cocentric with each other, and the ratio between the radius of the outer edge of the second sub-end cover connection area and the inner edge of the second sub-end cover connection area is 1.1-1.

3.

29. The battery cell according to any one of claims 19 to 28, characterized in that: When the current collecting component is laid flat, the outer edge of the first sub-end cover connection area and the outer edge of the transition area are respectively arranged in an arc shape and are arranged cocentrically with each other.

30. The battery cell according to any one of claims 19 to 28, characterized in that: When the current collecting component is in a flat state, the outer edge of the tab connection area is arranged in an arc shape, and the current collecting component further has a reference circle with a radius of a line connecting the outermost connection point of the first sub-end cover connection area and the transition area along the second reference direction to the center of the outer edge of the tab connection area, and the outer edge of the transition area is located inside the reference circle and is spaced apart from the reference circle.

31. The battery cell according to claim 30, characterized in that The width of the interval between the outer edge of the transition region and the reference circle along the second reference direction gradually widens in a direction from the first sub-end cover connection region to the tab connection region.

32. The battery cell according to claim 30 or 31, characterized in that: The transition region is arranged in a trapezoidal shape, and the width of the transition region along the second reference direction gradually widens in a direction from the first sub-end cover connection region to the tab connection region.

33. The battery cell according to any one of claims 18 to 32, characterized in that: In the flat state of the current collecting component, when the outer edge of the tab connection area is projected toward the end cover connection area along the first reference direction, the projection of the outermost point of the outer edge of the tab connection area in the second reference direction is located outside the inner edge of the second sub-end cover connection area.

34. The battery cell according to claim 33, characterized in that The outer edge of the tab connection area and the inner edge of the second sub-end cover connection area are respectively arranged in an arc shape and are cocentric with each other. The radius of the outer edge of the tab connection area is greater than the radius of the inner edge of the second sub-end cover connection area.

35. The battery cell according to any one of claims 19 to 34, characterized in that: The current collecting component is provided with a first trace line and a second trace line along the second reference direction, the first trace line is configured to allow the tab connection area to be bent relative to the transition area along the first trace line, and the second trace line is configured to allow the first sub-end cover connection area to be bent relative to the transition area along the second trace line.

36. The battery cell according to claim 35, characterized in that In the flattened state, the first trace line and the second trace line have a first distance along the first reference direction, and the second trace line has a second distance along the first reference direction to the outer edge of the first sub-end cover connection area, and the first distance is greater than the maximum value of the second distance, so that in the bent state, the outer edge of the end cover assembly maintains a predetermined distance from the plane where the first main surface of the tab connection area is located.

37. The battery cell according to any one of claims 19 to 36, characterized in that: The ratio of the minimum flow area S of the transition zone to the battery capacity C of the battery cell is greater than or equal to 0.15 mm2 / Ah, and the minimum flow area of ​​the transition zone is the product of the minimum width of the transition zone along the second reference direction and the thickness of the transition zone.

38. The battery cell according to any one of claims 1 to 37, characterized in that: The electrode assembly includes an electrode body arranged in a cylindrical shape, the outer edge of the tab connection area is arranged in an arc shape, and the ratio of the radius of the outer edge of the tab connection area to the radius of the electrode assembly is greater than or equal to 0.

8.

39. The battery cell according to any one of claims 1 to 38, characterized in that: The current collecting component is further provided with a hollow portion.

40. The battery cell according to claim 39, characterized in that The outer edge of the tab connection area is arranged in an arc shape and the hollow portion is located at the center of the outer edge of the tab connection area, or the hollow portion is entirely located in the tab connection area.

41. The battery cell according to any one of claims 1 to 40, characterized in that: The end cap assembly includes an end cap, the electrode lead-out portion includes at least a partial area on the end cap, and the end cap covers the opening.

42. The battery cell according to claim 41, characterized in that The electrode lead-out portion includes an annular boss of the end cover protruding toward the electrode assembly, the end cover connection area is welded to the top surface of the annular boss, and the outer edge of the tab connection area overlaps the top surface of the annular boss.

43. The battery cell according to claim 42, characterized in that The outer edge of the tab connection area is arranged in an arc shape, and the radius of the outer edge of the tab connection area is larger than the inner edge radius of the annular boss and smaller than the outer edge radius of the annular boss.

44. The battery cell according to any one of claims 1 to 40, characterized in that: The housing is electrically connected to the end cover, and the housing includes a bottom wall arranged opposite to the end cover, and the bottom wall is provided with an electrode terminal protruding from the bottom wall; The electrode assembly further includes a second electrode tab having a polarity opposite to that of the first electrode tab. The second electrode tab is located on a side of the electrode assembly facing the electrode terminal, and the second electrode tab is electrically connected to the electrode terminal.

45. A battery, characterized in that include: A battery cell according to any one of claims 1 to 44.

46. ​​An electrical device, characterized in that: The electrical device comprises the battery according to claim 45.

47. An assembly component for a battery cell, characterized in that: The assembly components include: an end cap assembly, wherein the end cap assembly is provided with an electrode lead-out portion; A current collecting component, wherein the current collecting component has a first reference direction and a second reference direction arranged along the main surface of the current collecting component and perpendicular to each other in a flat state, and the current collecting component includes a tab connection area, a transition area and an end cover connection area arranged in sequence along the first reference direction, the first main surface of the end cover connection area is in contact with the electrode lead-out portion, and is welded to the battery lead-out portion through a first weld portion formed from the second main surface of the end cover connection area, wherein the penetration formed by the first weld portion on the electrode lead-out portion is less than or equal to the thickness of the electrode lead-out portion.

48. The assembly according to claim 47, wherein: The transition zone is configured to be able to be bent relative to the end cover connection zone, and the tab connection zone is configured to be able to be bent relative to the transition zone, so that the current collecting component is in a bent state. In the bent state, a clearance is formed between the end cover and the first main surface of the tab connection zone to allow the tab connection zone to be welded to the first tab through a second weld portion formed from the first main surface of the tab connection zone when the second main surface of the tab connection zone is fitted with the first tab of the electrode assembly, wherein the first main surface of the tab connection zone and the first main surface of the end cover connection zone are located on the same side of the current collecting component.

49. The assembly according to claim 48, wherein: The current collecting component is configured to be pre-bent into the bent state and to maintain the bent state when not subjected to external force.

50. The assembly according to any one of claims 47 to 49, wherein: The current collecting component is configured to be able to unfold into an unfolded state when the tab connection area is welded to the first tab and the end cover assembly is covered on the shell accommodating the electrode assembly, wherein in the unfolded state, the tab connection area, the transition area and the end cover connection area are arranged non-overlappingly along the axial direction of the battery cell.

51. The assembly according to any one of claims 47 to 50, wherein: The end cover connection area includes a first sub-end cover connection area connected to the transition area and a second sub-end cover connection area connected to the first sub-end cover connection area. In the flattened state, the second sub-end cover connection area is located outside the transition area at least along the second reference direction and extends toward the tab connection area. A certain gap is maintained between the second sub-end cover connection area and the transition area and the tab connection area. The first sub-end cover connection area and the second sub-end cover connection area are respectively welded to the electrode lead-out portion through the first welding portion.

52. The assembly according to claim 51, wherein: The second sub-end cover connection region further extends to be located outside the tab connection region along the second reference direction.

53. An assembly according to claim 51 or 52, characterized in that The number of the second sub-end cover connection area is one, and both ends of the second sub-end cover connection area are respectively connected to the first sub-end cover connection area and are arranged around the transition area and the tab connection area, or the number of the second sub-end cover connection area is two, and they are respectively located at least on opposite sides of the transition area along the second reference direction.

54. The assembly according to any one of claims 51 to 53, wherein: In the flattened state, the tab connection area and the first sub-end cover connection area are respectively arranged in a circular segment shape, and the outer edges of the tab connection area and the first sub-end cover connection area are respectively arranged in an arc shape and are arranged cocentrically with each other.

55. The assembly according to any one of claims 51 to 54, wherein: In the flattened state, the outer edge of the tab connection area is arranged in an arc shape, and there is an angle between the first sub-end cover connection area and the line connecting the two outermost connection points of the transition area along the second reference direction to the center of the circle of the outer edge of the tab connection area, and the angle is smaller than the central angle of the outer edge of the tab connection area.

56. The assembly according to any one of claims 51 to 55, wherein: In the flattened state, the outer edge of the first sub-end cover connection area and the outer edge of the second sub-end cover connection area are respectively arranged in an arc shape, and are cocentric and have the same radius with each other, and the inner edge of the second sub-end cover connection area is arranged in an arc shape, and is cocentric with the outer edge of the first sub-end cover connection area.

57. The assembly according to any one of claims 51 to 56, wherein: In the flattened state, the outer edge of the tab connection area is arranged in an arc shape, and the current collecting component further has a reference circle with a radius of a line connecting the outermost connection point of the first sub-end cover connection area and the transition area along the second reference direction to the center of the outer edge of the tab connection area, and the outer edge of the transition area is located inside the reference circle and is spaced apart from the reference circle.

58. The assembly according to claim 57, wherein: The width of the interval between the outer edge of the transition zone and the reference circle along the second reference direction gradually widens in the direction from the first sub-end cover connection area to the tab connection area, and / or the transition zone is arranged in a trapezoidal shape, and the width of the transition zone along the second reference direction gradually widens in the direction from the first sub-end cover connection area to the tab connection area.

59. The assembly according to any one of claims 51 to 58, wherein: In the flattened state, when the outer edge of the tab connection area is projected toward the end cover connection area along the first reference direction, the projection of the outermost point of the outer edge of the tab connection area in the second reference direction is located outside the inner edge of the second sub-end cover connection area.

60. The assembly according to claim 59, wherein: The outer edge of the tab connection area and the inner edge of the second sub-end cover connection area are respectively arranged in an arc shape and are cocentric with each other. The radius of the outer edge of the tab connection area is greater than the radius of the inner edge of the second sub-end cover connection area.

61. The assembly according to any one of claims 51 to 60, wherein: The current collecting component is provided with a first trace line and a second trace line along the second reference direction, the first trace line is provided to allow the pole tab connection area to be bent relative to the transition area along the first trace line, and the second trace line is provided to allow the first sub-end cover connection area to be bent relative to the transition area along the second trace line. In the flattened state, there is a first distance between the first trace line and the second trace line along the first reference direction, and a second distance between the second trace line and the outer edge of the first sub-end cover connection area along the first reference direction. The first distance is greater than the maximum value of the second distance, so that in the bent state, the outer edge of the end cover maintains a predetermined distance from the plane where the first main surface of the pole tab connection area is located.

62. The assembly according to any one of claims 47 to 61, wherein: The current collecting component is further provided with a hollow portion.

63. The assembly according to claim 62, wherein: The outer edge of the tab connection area is arranged in an arc shape and the hollow portion is located at the center of the outer edge of the tab connection area, or the hollow portion is entirely located in the tab connection area.

64. The assembly according to any one of claims 47 to 63, wherein: The end cover assembly includes an end cover, which covers the opening of the shell. The electrode lead-out portion includes an annular boss protruding from the end cover toward the electrode assembly. The end cover connection area is welded to the top surface of the annular boss, and after welding, the outer edge of the tab connection area can overlap the top surface of the annular boss.

65. A method for assembling a battery cell, characterized in that: The assembly method comprises: Providing an assembly assembly according to any one of claims 47 to 64, wherein the current collecting component is in a bent state, and in the bent state, a clearance is formed between the end cap assembly and the first main surface of the tab connection area; Laminating the second main surface of the tab connection area to the first tab of the electrode assembly; The tab connection region is welded to the first tab from a first major surface of the tab connection region.

66. The assembly method according to claim 65, characterized in that The assembly method further comprises: The end cover assembly is placed on the opening of the shell that accommodates the electrode assembly so that the current collecting component is arranged between the electrode assembly and the end cover assembly and unfolded into an unfolded state, wherein in the unfolded state, the tab connection area, the transition area and the end cover connection area are arranged non-overlappingly along the axial direction of the battery cell.

67. A method for assembling a battery cell, characterized in that: The assembly method comprises: An electrode assembly, an end cap assembly, and a current collecting component are provided, wherein the electrode assembly includes a first electrode tab, the end cap assembly is provided with an electrode lead-out portion, and the current collecting component includes a tab connection area and an end cap connection area; A first weld for welding the end cap connection area and the electrode lead-out portion and a second weld for welding the tab connection area and the first tab are formed, wherein the penetration of the first weld on the electrode lead-out portion is less than the thickness of the electrode lead-out portion.

68. The assembly method according to claim 67, characterized in that The step of forming a first welding portion for welding the end cap connection area and the electrode lead portion and a second welding portion for welding the tab connection area and the first tab comprises: The current collecting component is bent into a bent state so that after one of the first welding portion and the second welding portion is formed, an avoidance is formed between the end cap assembly and the electrode assembly, thereby forming the other of the first welding portion and the second welding portion.

69. The assembly method according to claim 67 or 68, characterized in that The first weld portion is formed from a side of the end cap connection region away from the electrode lead portion, and the second weld portion is formed from a side of the tab connection region away from the first tab.

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