Pole and processing method thereof, top cover assembly, battery monomer, battery and power utilization device

Abstract

The invention relates to a pole and a processing method thereof, a top cover assembly, a battery monomer, a battery and a power utilization device. The pole comprises at least one first connecting part and at least two second connecting parts, the at least two second connecting parts are arranged at intervals along a first preset direction, one first connecting part is arranged between every two adjacent second connecting parts, and each first connecting part is connected with the two adjacent second connecting parts; the first connecting part is used for being connected with an electric connecting piece, and one side surface of the first connecting part in the thickness direction of the pole is a first surface; and each second connecting part protrudes out of the first surface of the first connecting part along the thickness direction of the pole, and the second connecting parts are used for being connected with tabs.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and specifically to a pole, a top cover assembly, a battery cell, a battery and an electrical device. Background Art

[0002] Lithium-ion batteries have the advantages of high energy density, long cycle life, high rate performance, good safety and environmental protection, and are important energy products for modern electronic products and power vehicles. Battery cells are an important component of batteries.

[0003] There are two technical solutions for battery cells: with and without adapters. In the technical solution with adapters, the tabs of the battery cell are led to the poles through the adapters, so that the poles serve as the electrode terminals of the battery cells. However, the presence of the adapters increases the number of parts and the cost of the battery. On the other hand, the welding process between the tabs and the adapters is added, which further increases the cost of the battery.

[0004] In the technical solution without the adapter, the pole and the tab are directly connected. However, due to the limited space on the cover plate, there are restrictions on the position of the pole, so it is necessary to extend the tab to achieve direct connection between the pole and the tab. Extending the tab greatly increases the risk of the tab being inserted into the battery cell and the tab being torn. Summary of the invention

[0005] Based on this, it is necessary to provide a pole and processing method, a top cover assembly, a battery cell, a battery, and an electrical device that can omit the adapter and avoid lengthening the pole ear in order to solve the above problems.

[0006] On the one hand, the present application provides a pole, comprising at least one first connection portion and at least two second connection portions, at least two of the second connection portions are arranged at intervals along a first preset direction, one first connection portion is arranged between each two adjacent second connection portions, and each first connection portion is connected to two adjacent second connection portions; the first connection portion is used to connect to an electrical connector, and a side surface of the first connection portion in the thickness direction of the pole is a first surface; each of the second connection portions protrudes from the first surface of the first connection portion in the thickness direction of the pole, and the second connection portion is used to connect to a pole ear.

[0007] In some of the embodiments, on an imaginary plane perpendicular to the thickness direction of the pole, the orthographic projection of the first connecting portion does not overlap with the orthographic projections of each of the second connecting portions.

[0008] In some embodiments, the first connection portion and each of the second connection portions are integrally formed.

[0009] In some embodiments, the first connection portion and each of the second connection portions are stamped integrally formed structures.

[0010] In some embodiments, two second connection parts are provided, and the two second connection parts are respectively connected to two sides of the first connection part in the first preset direction.

[0011] In some embodiments, a distance W2 between ends of two second connection parts that are away from each other is 20 mm-70 mm.

[0012] In some embodiments, a dimension W6 of each second connection portion in the second preset direction is 20 mm to 60 mm, and the first preset direction, the second preset direction and the pole thickness direction are perpendicular to each other.

[0013] In some embodiments, each of the second connecting portions has a second surface on one side in the thickness direction of the pole, the second surface and the first surface are located on the same side of the pole in the thickness direction, and the second surface protrudes beyond the first surface of the first connecting portion in the thickness direction of the pole.

[0014] In some embodiments, the first connecting portion further has a third surface opposite to the first surface, and each of the second connecting portions further has a fourth surface opposite to the second surface; The third surface protrudes from a side of the second connection portion having the fourth surface in the thickness direction of the pole.

[0015] In some embodiments, each of the second connecting portions includes a first region and a second region surrounding the first region, the second region is connected to the first connecting portion, and the first region protrudes relative to the second region along the thickness direction of the pole to form a connecting sub-portion; A surface of the second region facing away from the connecting sub-portion in the thickness direction of the pole is the fourth surface, and a surface of the connecting sub-portion facing away from the second region in the thickness direction of the pole is the second surface.

[0016] In some embodiments, the second region has a fifth surface that is opposite to the fourth surface, and the fifth surface protrudes from the first surface of the first connecting portion in the thickness direction of the pole.

[0017] In some embodiments, a protrusion is provided on the second surface of the connecting sub-part.

[0018] In some embodiments, the connecting sub-portion has a first groove, and a notch of the first groove passes through an end of the connecting sub-portion facing away from the second surface.

[0019] In some embodiments, in the thickness direction of the pole, the bottom of the first groove is located on a side of the first surface away from the third surface.

[0020] In some embodiments, the depth dimension D2 of the first groove is 1 mm to 5 mm; and / or A width dimension W4 of the notch of the first groove in the first preset direction is 4 mm to 25 mm, a width dimension W5 of the groove bottom of the first groove in the first preset direction is 2 mm to 20 mm, and W5<W4.

[0021] In some embodiments, the connecting sub-portion has a bottom wall and an annular side wall, one end of the annular side wall is connected to the second region, the bottom wall is connected to the other end of the annular side wall, and the annular side wall and the bottom wall together enclose the first groove; In the direction from the second area to the bottom wall, the outer contour size of the annular side wall decreases gradually or in a step-like manner.

[0022] In some embodiments, the angle between the inner surface of the annular side wall and an imaginary axis is α, the imaginary axis is parallel to the thickness direction of the pole, and the angle between the outer surface of the annular side wall and the imaginary axis is β; α is 5° to 60° and / or β is 5° to 60°.

[0023] In some of these embodiments, α=β.

[0024] In some embodiments, the thickness dimension of the annular side wall is T14, the thickness dimension of the bottom wall is T12, the thickness dimension of the second region is T11, and T12 ≥ T11 > T14.

[0025] In some of the embodiments, T12 and T11 satisfy: T12-T11=0-2 / 3×T11.

[0026] In some embodiments, the second region includes a first straight portion, a first arc portion, a second straight portion and a second arc portion which are connected end to end in sequence, the first straight portion and the second straight portion are respectively located on both sides of the first region in the first preset direction, the first arc portion and the second arc portion are respectively located on both sides of the first region in the second preset direction, and the first preset direction, the second preset direction and the pole thickness direction are perpendicular to each other.

[0027] In some embodiments, the curvature radius R of the outer edge of the first arc portion and the outer edge of the second arc portion is 3 mm to 8 mm.

[0028] In some embodiments, the first connecting portion has a boss and an annular surface on a side opposite to the first surface; the annular surface is arranged around the boss, and the boss protrudes relative to the annular surface in a direction away from the first surface.

[0029] In some embodiments, a protruding height H1 of the boss relative to the annular surface is 0.05 mm to 0.8 mm.

[0030] In some embodiments, a second groove is formed on the first surface of the first connecting portion, and at least a portion of the second groove gradually narrows or stepwise narrows in a direction from the groove bottom to the groove opening.

[0031] In some embodiments, the depth dimension of the second groove is H2, the thickness dimension of the first connecting portion is T9, and H2 and T9 satisfy: H2=(5%-50%)T9.

[0032] In some embodiments, the pole further includes a transition portion, and each of the second connection portions is connected to the corresponding first connection portion through the transition portion; One end of the transition portion connected to the second connection portion is a first end, and the first end at least partially protrudes from a side of the first connection portion having the first surface along the thickness direction of the pole.

[0033] In some embodiments, the flow area of ​​the transition portion is smaller than the flow area of ​​the first connection portion, and smaller than the flow area of ​​the second connection portion.

[0034] In some embodiments, the thickness dimension of the first connecting portion is T9, the thickness dimension of the transition portion is T13, the thickness dimension of the second region is T11, and T9≥T11>T13.

[0035] In some embodiments, the connecting sub-portion has a first groove, and the notch of the first groove passes through an end of the connecting sub-portion away from the second surface; the connecting sub-portion has a bottom wall and an annular side wall, one end of the annular side wall is connected to the second area, the bottom wall is connected to the other end of the annular side wall, and the annular side wall and the bottom wall together enclose the first groove; The thickness dimension of the annular side wall is T14, the thickness dimension of the bottom wall is T12, and T9≥T12≥T11>T13>T14.

[0036] In some embodiments, the pole includes a first metal layer and a second metal layer, the first metal layer extends to the first connecting portion and each of the second connecting portions; at each of the second connecting portions, the second metal layer and the first metal layer are stacked along the thickness direction of the pole, and a surface of the first metal layer facing away from the second metal layer includes the fourth surface, a surface of the second metal layer facing away from the first metal layer is a sixth surface, and the sixth surface includes the second surface.

[0037] In some embodiments, the transition portion has a seventh surface, the seventh surface and the sixth surface are located on the same side of the pole in the thickness direction, and the seventh surface and the sixth surface are transitioned through an arc segment; An end of the second metal layer close to the first connecting portion has a first interface, and a preset distance L exists between the first interface and the arc segment.

[0038] In some embodiments, the preset distance L satisfies: 0.5 mm ≤ L ≤ 6 mm.

[0039] In some embodiments, the connecting sub-portion has a first groove, and the notch of the first groove passes through an end of the connecting sub-portion away from the second surface; the connecting sub-portion has a bottom wall and an annular side wall, one end of the annular side wall is connected to the second area, the bottom wall is connected to the other end of the annular side wall, and the annular side wall and the bottom wall together enclose the first groove; The thickness of the second metal layer at the annular side wall is T7, the thickness of the second metal layer at the second region is T3, the thickness of the second metal layer at the bottom wall is T5, and T7, T5 and T3 satisfy: T5≥T3>T7.

[0040] In some embodiments, the thickness T5 of the second metal layer at the bottom wall is 0.3 mm to 1.8 mm; and / or the thickness T5 of the second metal layer at the bottom wall accounts for 10% to 40% of the thickness of the bottom wall.

[0041] In some embodiments, the thickness T3 of the second metal layer in the second region is 0.05 mm to 1.5 mm; and / or the thickness T3 of the second metal layer in the second region accounts for 10% to 40% of the thickness of the second region.

[0042] In some embodiments, a second interface is formed between the first metal layer and the second metal layer at the second region; In the thickness direction of the pole, the second interface protrudes from the first surface of the first connecting portion.

[0043] In some embodiments, the second metal layer extends to each of the transition portions and the first connecting portion.

[0044] In some embodiments, the thickness of the second metal layer at the second region is T3, the thickness of the second metal layer at the transition portion is T8, and the thickness of the second metal layer at the first connection portion is T2; T3, T8 and T2 satisfy: T8<T3≤T2.

[0045] In some embodiments, the connecting sub-portion has a first groove, and the notch of the first groove passes through an end of the connecting sub-portion away from the second surface; the connecting sub-portion has a bottom wall and an annular side wall, one end of the annular side wall is connected to the second area, the bottom wall is connected to the other end of the annular side wall, and the annular side wall and the bottom wall together enclose the first groove; The thickness of the second metal layer at the bottom wall is T5, the thickness of the second metal layer at the annular side wall is T7, and T7<T8<T3≤T5≤T2.

[0046] In some of the embodiments, T5, T3 and T2 satisfy: T5-T3=0-0.5×T2.

[0047] In some embodiments, the first metal layer is an aluminum layer, and the second metal layer is a copper layer.

[0048] On the other hand, the present application provides a top cover assembly, including a cover plate and a pole as described in any of the above embodiments; The cover plate is provided with a first through hole, the first connection portion is arranged on one side of the cover plate, a first surface of the first connection portion faces the cover plate, and the second connection portion passes through the first through hole to the other side of the cover plate.

[0049] On the other hand, the present application provides a battery cell, characterized in that it includes a shell, a battery cell assembly and a top cover assembly as described in any of the above embodiments; At least one end of the shell is open, the battery cell assembly is accommodated in the shell, the top cover assembly covers the opening, and the thickness direction of the shell is consistent with the first preset direction; the battery cell assembly includes at least two groups of battery cells arranged in parallel along the thickness direction of the shell, and at least two groups of battery cells are arranged in a one-to-one correspondence with at least two second connecting parts, and the end face of each group of battery cells extends with a pole ear, and the pole ear of each group of battery cells is respectively connected to the corresponding second connecting part.

[0050] On the other hand, the present application provides a battery, comprising a plurality of battery cells as described in any of the above embodiments, wherein the plurality of battery cells are electrically connected via an electrical connector, and the electrical connector is connected to the first connecting portion.

[0051] On the other hand, the present application provides an electrical device, characterized in that it includes a battery cell as described in any of the above embodiments, or includes a battery as described in any of the above embodiments.

[0052] On the other hand, the present application provides a method for preparing a pole as generally described in any of the above embodiments, comprising the following steps: providing a plate; The sheet material is pressed and drawn; a first connection area and a plurality of second connection areas are formed on the sheet material by pressing the sheet material; the first connection part is formed in the first connection area, and the second connection part is formed in each of the second connection areas by drawing the sheet material; The plate is punched to obtain the pole.

[0053] Compared with the prior art, this application has the following beneficial effects: In the above-mentioned processing methods of the pole, top cover assembly, battery cell, battery, electrical device and pole, the pole is directly connected to the pole ears of the two groups of battery cells through two second connecting parts. On the one hand, it avoids the use of adapters, thereby reducing the number of parts of the top cover assembly and reducing one welding process; on the other hand, by arranging the two second connecting parts along the arrangement direction of the two groups of battery cells, the two second connecting parts pass through the cover plate through the first through holes on the cover plate and are respectively connected to the pole ears of the two groups of battery cells, avoiding the need to extend the pole ears, thereby greatly reducing the risk of adverse phenomena such as the pole ears being inserted into the battery cells and the pole ears being torn. BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Figure 1 A cross-sectional view of a battery cell in one embodiment of the present application; Figure 2 This is a schematic diagram of the structure of a top cover assembly in one embodiment of the present application; Figure 3 for Figure 2 A top view of the top cover assembly is shown; Figure 4 for Figure 2 A schematic diagram of the structure of the pole of the top cover assembly shown; Figure 5 for Figure 4 A top view of the pole shown; Figure 6 for Figure 5 a bottom view of the top cover assembly shown; Figure 7 for Figure 2 A cross-sectional view of the top cover assembly at the pole (the cross section is perpendicular to the length direction of the cover plate); Figure 8 for Figure 7 A cross-sectional view of a pole of the top cover assembly shown (the cross section is perpendicular to the length direction of the cover); Fig. 9 A cross-sectional view of a top cover assembly in another embodiment of the present application (the cross section is perpendicular to the length direction of the cover plate); Fig.10 for Fig. 9 A cross-sectional view of a pole of the top cover assembly shown (the cross section is perpendicular to the length direction of the cover); Fig.11 A cross-sectional view of a top cover assembly in another embodiment of the present application (the cross section is perpendicular to the length direction of the cover plate); Fig.12 A cross-sectional view of a top cover assembly in another embodiment of the present application (the cross section is perpendicular to the length direction of the cover plate); Fig.13 A step-by-step diagram (axonometric diagram) illustrating a method for processing a pole in an embodiment of the present application; Fig.14 To demonstrate the use of the cross-sectional view of the pole Fig.13 The step demonstration diagram of the processing method shown; Fig.15 This is a step-by-step illustration (cross-sectional view) of a method for processing a pole in another embodiment of the present application. DETAILED DESCRIPTION

[0055] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0056] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0057] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0058] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0059] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0060] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0061] An embodiment of the present application provides an electrical device, a battery and a battery cell. The electrical device uses the following battery or battery cell as its power source. Among them, the above-mentioned electrical device can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, an energy storage device, an amusement equipment, an elevator and a lifting equipment, etc. Electric toys include fixed or mobile electric toys, such as game consoles, electric car toys, electric ship toys or electric airplane toys, etc.; electric tools include metal cutting electric tools, grinding electric tools, assembly electric tools and railway electric tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete vibrators and electric planers, etc.; energy storage equipment can be energy storage walls, base station energy storage, container energy storage, etc.; amusement equipment can be carousels, jumping machines, etc.

[0062] The vehicle 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. For new energy vehicles, the above-mentioned battery can be used as a driving power source to replace fossil fuels to provide driving power. This application does not impose any special restrictions on the above-mentioned electrical devices.

[0063] The above-mentioned battery can be a battery pack or a battery module. When the above-mentioned battery is a battery pack, the battery pack specifically includes a battery management system (BMS) and a plurality of the above-mentioned battery cells. The plurality of battery cells can be electrically connected in series, in parallel, or in a combination of series and parallel, and can be communicatively connected with the battery management system, which controls and monitors the working status of each battery cell. In addition, a plurality of battery cells can also first form a battery module with a module management system, and then a plurality of battery modules can be electrically connected in series, in parallel, or in a combination of series and parallel, and together with the battery management system form a battery pack.

[0064] A plurality of battery cells can be installed on supporting structures such as boxes, frames, and brackets. Each battery cell and each battery cell and the battery management system can be electrically connected through an electrical connector, which can be a bus. In addition, each battery cell can also be electrically connected by plugging in its own pole. For example, between two adjacent battery cells, a slot is provided on the pole of one battery cell, and a plug-in is correspondingly provided on the pole of the other battery cell. The plug-in is inserted into the slot to achieve electrical connection. Therefore, for a battery cell, the aforementioned electrical connector can be the pole of another battery cell. Similarly, the battery cell and the battery management system can also be electrically connected by plugging in each other, which is not repeated here. The above-mentioned battery cell can be a lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery, and its external contour can be a cylinder, a flat body, a rectangular parallelepiped, or other shapes, but it is not limited thereto. Specifically in the present embodiment, the above-mentioned battery cell is a lithium-ion square battery.

[0065] See also Figure 1 Specifically, the battery cell 1 includes a top cover assembly 100, a shell 200 and a battery cell assembly 300. The shell 200 is a hollow structure, and has a receiving space inside for accommodating the battery cell assembly 300, electrolyte and other components. At least one end of the shell 200 is provided with an opening, and the battery cell assembly 300 can be loaded into the shell through the opening of the shell 200. Since the battery cell 1 in this embodiment is a square battery, the outer contour of the shell 200 is a rectangular parallelepiped, and its opening is rectangular. The top cover assembly 100 is installed on the shell 200 and covers the opening of the shell 200, thereby enclosing the battery cell assembly 300 in the shell 200. Since the shape of the top cover assembly 100 needs to match the shape of the opening of the shell 200, the top cover assembly 100 is roughly rectangular.

[0066] The battery cell assembly 300 is the core component of the battery cell 1. In order to adapt to the shape of the shell 200, the battery cell assembly 300 in this embodiment is in the shape of a rectangular parallelepiped. Among them, the battery cell assembly 300 generally includes at least two groups of battery cells 301 arranged in parallel along the thickness direction of the shell 200, and each group of battery cells 301 extends a pole ear 302. Each group of battery cells 301 may include one or more battery cells 301. The battery cell 301 can be formed by winding or laminating a positive electrode sheet, a negative electrode sheet, and a diaphragm that acts as an insulator between the negative electrode sheet and the positive electrode sheet. The battery cell 301 formed by winding can be pressed into a flat shape. The pole ear 302 of each battery cell 301 is divided into a positive pole ear (not marked in the figure) and a negative pole ear (not marked in the figure), and the positive pole ear and the negative pole ear are respectively led out from the positive electrode sheet and the negative electrode sheet.

[0067] The positive pole ear and the negative pole ear may be located at the same end of the battery cell 301, or the positive pole ear may be located at one end of the battery cell 301, and the negative pole ear may be located at the other opposite end of the battery cell 301. Specifically in the present embodiment, the battery cell assembly 300 includes two groups of battery cells 301, each group of battery cells 301 includes one battery cell 301, and the positive pole ear and the negative pole ear of each battery cell 301 are located at the same end of the battery cell 301 and are spaced along the length direction of the battery cell assembly 300, that is, the length direction of the shell 200. Therefore, a total of four groups of pole ears 302 are provided at one end of the battery cell assembly 300, two of which are negative pole ears spaced along the width direction of the shell 200, and the other two groups are positive pole ears spaced along the width direction of the shell 200, and the two groups of negative pole ears and the two groups of positive pole ears are spaced along the length direction of the shell 200. When each group of cells 301 includes multiple cells 301, the positive tabs of the multiple cells 301 are put together to form a group of positive tabs, and the negative tabs are put together to form a group of negative tabs. The width direction of the housing 200 is also its thickness direction, and the width direction of the cell assembly 300 is also its thickness direction.

[0068] Before the battery cell assembly 300 is installed in the housing 200, it needs to be assembled with the top cover assembly 100. Specifically, the tab 302 of the battery cell assembly 300 needs to be electrically connected to the pole 30 on the top cover assembly 100 (see Figure 2 ), and then install the battery cell assembly 300 into the shell 200, so that the operation will not be limited by the narrow space in the shell 200.

[0069] As an embodiment, the battery cell assembly 300 includes two groups of battery cells 301 , each group of battery cells 301 includes one battery cell 301 , that is, the battery cell assembly 300 includes two battery cells 301 in total, and the two battery cells 301 are arranged side by side along the thickness direction of the shell 200 .

[0070] The specific structure of the top cover assembly is described in detail below in conjunction with the accompanying drawings.

[0071] See also Figures 1 to 4 As shown, in an embodiment of the present application, the top cover assembly 100 includes a cover plate 10 and a pole 30. The cover plate 10 is provided at the opening of the housing 200 to seal the opening of the housing 200. The cover plate 10 can be formed of a material with high mechanical strength, such as aluminum, aluminum alloy or stainless steel. Specifically, the cover plate 10 in this embodiment is roughly rectangular and matches the opening shape of the housing 200. A first through hole 11 is provided on the cover plate 10, and the pole 30 is mounted on the cover plate 10 through the first through hole 11.

[0072] The pole 30 is arranged on the cover plate 10, and the thickness direction Z of the pole 30 is consistent with the thickness direction of the cover plate 10. Since the positive and negative ears of the battery cell assembly 300 are located at the same end, the cover plate 10 is provided with positive poles and negative poles spaced apart from each other along the length direction. The positive pole is used to connect with the positive ear of each group of battery cells 301, and the negative pole is used to connect with the negative ear of each group of battery cells 301. Of course, in the case where the positive ear and the negative ear are respectively located at both ends of the battery cell assembly 300, only one of the positive pole and the negative pole needs to be arranged on the cover plate 10. The positive pole serves as the positive terminal of the battery cell 1, and the negative pole serves as the negative terminal of the battery cell 1. The positive and negative terminals of each battery cell 1 are connected by electrical connectors to realize the series connection, parallel connection or mixed connection of each battery cell 1. The electrical connector can be a bus bar or a pole 30 of other battery cells 1.

[0073] It should be noted that, since the structures of the positive electrode column and the negative electrode column are similar, for ease of understanding, this article takes one of the electrode columns 30 as an example. That is to say, the "electrode column" in this article can be a positive electrode column or a negative electrode column (unless otherwise specified), and the "electrode lug" in this article can be a positive electrode lug or a negative electrode lug (unless otherwise specified), as long as all the electrode lugs connected to the positive electrode column are positive electrode lugs, and all the electrode lugs connected to the negative electrode column are negative electrode lugs.

[0074] Specifically, the pole 30 includes a first connection portion 31 and two second connection portions 32. The two second connection portions 32 are arranged at intervals along the first preset direction X. A first connection portion 31 is arranged between the two second connection portions 32, and the first connection portion 31 is connected to two adjacent second connection portions 32. The first connection portion 31 is arranged on the side of the cover plate 10 away from the battery cell assembly 300 (i.e., the outer side of the cover plate 10), and is used to connect with the electrical connector. The above-mentioned first preset direction X is consistent with the thickness direction of the shell 200, that is, the arrangement direction of the two second connection portions 32 is consistent with the arrangement direction of the two groups of battery cells 301, so that the two second connection portions 32 correspond to the pole ears 302 of the two groups of battery cells 301 one by one. At least part of each second connection portion 32 is penetrated through the first through hole 11 on the cover plate 10 and connected to the corresponding pole ear 302, thereby realizing that the pole 30 is directly connected to each pole ear 302.

[0075] Furthermore, the side of the first connection portion 31 facing the cover plate 10 is the first surface b1. The two second connection portions 32 are both protruded from the first surface b1 of the first connection portion 31 along the thickness direction of the pole 30, so that the two second connection portions 32 are protruded relative to the first connection portion 31 toward the cover plate 10, so that the two second connection portions 32 pass through the first through hole 11 on the cover plate 10 to the side of the cover plate 10 facing the battery cell assembly 300 (i.e., the inner side of the cover plate 10), and then respectively connected to the pole ears 302 of the two groups of battery cells 301 in a one-to-one correspondence. In other words, the pole ears 302 of the two groups of battery cells 301 are respectively connected to the two second connection portions 32 in a one-to-one correspondence, and the two second connection portions 32 are electrically connected to the first connection portion 31, so that the first connection portion 31 serves as an electrode terminal of the battery cell.

[0076] In the above-mentioned top cover assembly 100, the pole 30 is directly connected to the pole ears 302 of the two groups of battery cells 301 through the two second connecting parts 32. On the one hand, the use of adapters is avoided, thereby reducing the number of parts of the top cover assembly 100 and reducing one welding process; on the other hand, by arranging the two second connecting parts 32 along the arrangement direction of the two groups of battery cells 301, the two second connecting parts 32 pass through the cover plate 10 through the first through holes 11 on the cover plate 10, and are respectively connected to the pole ears 302 of the two groups of battery cells 301, thereby avoiding the need to extend the pole ears 302, thereby greatly reducing the risk of adverse phenomena such as the pole ears 302 being inserted upside down into the battery cell 301 and the pole ears 302 being torn.

[0077] It should be noted that, in order to achieve direct connection between the pole 30 and the pole lug 302, the prior art also adopts a method of directly increasing the diameter of the pole 30. However, in the present application, by arranging the two second connecting parts 32 along the arrangement direction of the two groups of battery cells 301, the two second connecting parts 32 are inserted into the first through holes 11 on the cover plate 10 and can be directly electrically connected to the respective corresponding pole lugs 302, thereby avoiding the need to increase the diameter of the pole 30, which is conducive to saving the material of the pole 30 and reducing the cost of the pole 30.

[0078] It should also be noted that the number of the first connection parts 31 is not limited to one, and can be two or more. The number of the second connection parts 32 is also not limited to two, and can be three or more. The number of the first connection parts 31 and the second connection parts 32 is related to the number of groups of the battery cells 301. Specifically, the number of groups of the battery cells 301 is N groups, and the number of the second connection parts 32 is also set to N. The N second connection parts 32 are arranged at intervals along the first preset direction X, and a first connection part 31 is set between each two adjacent second connection parts 32. Each two adjacent second connection parts 32 are connected to the first connection part 31 between them, that is, the first connection part 31 is set to N-1. The N second connection parts 32 are respectively passed through the first through holes 11 on the cover plate 10 and are connected to the pole ears 302 of each group of battery cells 301 in a one-to-one manner. It should be noted that the number of groups of battery cells 301 is not the number of battery cells 301. For example, the battery cell assembly 300 includes four battery cells 301, of which two battery cells 301 form a group, and the pole tabs 302 of the two battery cells 301 are close together to form a group of pole tabs 302, and are connected to a second connecting portion 32. Another two battery cells 301 form a group, and the pole tabs 302 of the other two battery cells 301 are close together to form a group of pole tabs 302, and are connected to another second connecting portion 32. In this way, the number of groups of battery cells 301 is 2, but the number of battery cells 301 is 4, which are not the same. For ease of understanding, this article takes the battery cell assembly 300 including two groups of battery cells 301, each group of battery cells 301 includes one battery cell 301, and the pole 30 includes a first connecting portion 31 and two second connecting portions 32 as an example for explanation.

[0079] Specifically in this embodiment, the first through hole 11 on the cover plate 10 can be a single through hole with a larger opening range, which can allow at least two second connecting parts 32 to pass through together; the first through hole 11 can also be a through hole with a smaller opening range, and each first through hole 11 only allows one second connecting part 32 to pass through. Figure 3 A first through hole 11 is opened on the cover plate 10 at positions corresponding to the two second connecting parts 32 , so that the two second connecting parts 32 are respectively passed through a first through hole 11 corresponding to each other, and then respectively connected to the two tabs 302 on the inner side of the cover plate 10 .

[0080] It can be seen that the first through hole 11 is a through hole with a smaller opening range, and the area of ​​the cover plate 10 corresponding to the first connecting portion 31 does not need to be opened, so the opening area on the cover plate 10 can be reduced, thereby avoiding a significant decrease in the structural strength of the cover plate 10 caused by the opening.

[0081] by Figure 3 As shown in the example, four first through holes 11 are opened on the cover plate 10, two of which are located at one end of the cover plate 10 in the length direction and are spaced apart along the width direction of the cover plate 10, and the other two first through holes 11 are located at the other end of the cover plate 10 in the length direction and are also spaced apart along the width direction of the cover plate 10.

[0082] Specifically in this embodiment, the spacing W2 between the ends of the two second connection parts 32 of the pole 30 that are away from each other (i.e., the length dimension W2 of the pole 30 in the first preset direction X) is 20 mm to 70 mm. In this way, since the width dimension of the cover plate 10 (i.e., the dimension of the cover plate 10 in the first preset direction X) is limited, by setting W2 between 20 mm and 70 mm, on the one hand, it is ensured that the two second connection parts 32 are as close as possible to the two sides of the cover plate 10 in the first preset direction X. Since the tabs 302 of the two groups of battery cells 301 are respectively located near the two sides of the cover plate 10 in the width direction, the two second connection parts 32 are as close as possible to the corresponding tabs 302, thereby making the required length dimension of the tabs 302 smaller, avoiding the need to extend the length of the tabs 302; on the other hand, the length of the pole 30 is moderate, which can ensure that the electrical connection area between the second connection part 32 and the tab 302 and the electrical connection area between the first connection part 31 and the electrical connector are large enough to better meet the overcurrent requirements, and can also save materials and reduce costs.

[0083] Specifically, W2 in this embodiment can also be located in multiple intervals such as 20mm~30mm, 20mm~40mm, 20mm~50mm, 20mm~60mm, 60mm~70mm, 50mm~70mm, 40mm~70mm, 30mm~70mm, 20mm~40mm, 40mm~60mm and 30mm~50mm, and the specific selection can be made according to actual conditions. For example, W2 can be 20mm, 22mm, 24mm, 25mm, 26mm, 28mm, 30mm, 33mm, 35mm, 37mm, 39mm, 40mm, 42mm, 44mm, 45mm, 46mm, 48mm, 50mm, 53mm, 55mm, 57mm, 59mm, 60mm, 62mm, 64mm, 66mm, 65mm, 68mm or 70mm, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0084] In some other embodiments, the distance W2 between the ends of the two second connection portions 32 that are away from each other is (W1-30mm) to (W1-10mm), where W1 represents the width dimension of the cover plate 10 (ie, the dimension of the cover plate 10 in the first preset direction X). In this way, since the width dimension of the cover plate 10, the arrangement direction of the two groups of battery cells 301 and the arrangement direction of the two second connecting parts 32 are consistent, the spacing value W2 is designed according to the width dimension of the cover plate 10. On the one hand, the two second connecting parts 32 can be as close as possible to the two side edges of the cover plate 10 in the first preset direction X. Since the pole ears 302 of the two groups of battery cells 301 are respectively located close to the two side edges of the cover plate 10 in the width direction, the two second connecting parts 32 are as close as possible to their respective corresponding pole ears 302, thereby ensuring that the required length of the pole ears 302 is small and avoiding the need to extend the length of the pole ears 302. On the other hand, the length of the pole column 30 is moderate, which can ensure that the electrical connection area between the second connecting part 32 and the pole ear 302, and the electrical connection area between the first connecting part 31 and the electrical connector are large enough to better meet the overcurrent requirements, and can also take into account saving materials and reducing costs.

[0085] Specifically, W2 can be in multiple ranges such as (W1-25mm) to (W1-10mm), (W1-20mm) to (W1-10mm), (W1-15mm) to (W1-10mm), (W1-30mm) to (W1-15mm), (W1-30mm) to (W1-20mm), (W1-30mm) to (W1-25mm), and (W1-25mm) to (W1-15mm). For example, W2 can be (W1-30mm), (W1-28mm), (W1-26mm), (W1-24mm), (W1-22mm), (W1-20mm), (W1-19mm), (W1-17mm), (W1-15mm), (W1-13mm) or (W1-10mm), including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0086] Specifically in this embodiment, the dimension W3 of each second connection portion 32 in the first preset direction X satisfies: 3mm≤W3≤1 / 2×W2, thereby ensuring that the electrical connection area between the second connection portion 32 and the tab 302 is large enough to meet the overcurrent requirement while also saving materials and reducing costs.

[0087] Specifically in the embodiment, the dimension W6 of each second connection portion 32 in the second preset direction Y is 20 mm to 60 mm. The first preset direction X, the second preset direction Y and the thickness direction Z of the pole 30 are perpendicular to each other, that is, the first preset direction X is the width direction of the cover plate 10, the second preset direction Y is the length direction of the cover plate 10, and the thickness direction Z of the pole 30 is consistent with the thickness direction of the cover plate 10. In this way, by setting W6 between 20 mm and 60 mm, the connection area between the second connection portion 32 and the corresponding pole lug 302 is large enough, and on the premise of meeting the overcurrent requirements, materials are saved as much as possible to reduce costs.

[0088] Specifically, W6 in this embodiment can also be located in multiple ranges such as 20mm~30mm, 20mm~40mm, 20mm~50mm, 50mm~60mm, 40mm~60mm, 30mm~60mm, 25mm~35mm, 35mm~45mm, 30mm~50mm and 45mm~55mm, and the specific selection can be made according to actual conditions. For example, W6 can be 20mm, 22mm, 24mm, 25mm, 26mm, 28mm, 30mm, 31mm, 32mm, 33mm, 34mm, 35mm, 36mm, 37mm, 38mm, 39mm, 40mm, 41mm, 42mm, 43mm, 44mm, 45mm, 46mm, 47mm, 48mm, 49mm, 50mm, 53mm, 55mm, 57mm, 59mm or 60mm, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0089] Specifically in the embodiment, the dimension W7 of the first connection portion 31 in the second preset direction Y is smaller than W6. Wherein, W7=(40%~90%)W6. If the dimension of W7 is too small, the area where the first connection portion 31 is connected to the electrical connector is too small, which is not conducive to overcurrent; if the dimension of W7 is too large, the size of the original plate required for forming the pole 30 is too large, which increases the weight of the pole 30 and wastes materials. Therefore, the proportional relationship between W7 and W6 is limited within a suitable range, so that the connection area between the first connection portion 31 and the electrical connector is large enough, and the weight of the pole 30 is reduced as much as possible while meeting the overcurrent requirements, saving materials and reducing costs.

[0090] Specifically, W7 can be in multiple ranges such as (50%~90%) W6, (60%~90%) W6, (70%~90%) W6, (80%~90%) W6, (80%~90%) W6, (70%~90%) W6, (60%~90%) W6, (50%~60%) W6, (60%~70%) W6, (70%~80%) W6 and (55%~75%) W6, and the specific selection can be made according to actual situation. For example, W7 can be 50% W6, 52% W6, 54% W6, 56% W6, 58% W6, 60% W6, 63% W6, 65% W6, 67% W6, 69% W6, 70% W6, 72% W6, 74% W6, 76% W6, 77% W6, 78% W6, 79% W6, 80% W6, 81% W6, 82% W6, 83% W6, 84% W6, 85% W6, 86% W6, 87% W6, 88% W6, 89% W6 or 90% W6, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited herein.

[0091] Of course, in other embodiments, the dimension W7 of the first connection portion 31 in the second preset direction Y may also be set to be equal to the dimension W6 of the second connection portion 32 in the second preset direction Y, which is not limited here.

[0092] Specifically in this embodiment, the two second connection parts 32 are symmetrically arranged on both sides of the first connection part 31. Figure 7 , the distance J from the central axis of the second connection part 32 to the edge of the cover plate 10 is 4mm to 17mm. The spacing K between the central axis of the first connection part 31 and the central axis of the second connection part 32 is 0.5mm to 2mm. In this way, J and K are set within a more reasonable size range, on the one hand, to ensure that the required length of the pole ear 302 is small, avoiding the need to extend the length of the pole ear 302; on the other hand, the length of the pole 30 is moderate, which can ensure that the electrical connection area between the second connection part 32 and the pole ear 302, and the electrical connection area between the first connection part 31 and the electrical connector are large enough to better meet the overcurrent requirements, while saving materials and reducing costs.

[0093] Specifically, J can be in multiple ranges such as 4mm-7mm, 4mm-10mm, 4mm-13mm, 4mm-15mm, 13mm-17mm, 10mm-17mm, 7mm-17mm, 8mm-13mm, 8mm-10mm, 10mm-13mm and 9mm-12mm, and can be selected according to actual conditions. For example, J can be 4mm, 4.5mm, 5mm, 5.5mm, 6mm, 6.5mm, 7mm, 7.5mm, 8mm, 8.2mm, 8.4mm, 8.6mm, 8.8mm, 9mm, 9.3mm, 9.5mm, 9.7mm, 9.9mm, 10mm, 10.2mm, 10.4mm, 10.6mm, 10.8mm, 11mm, 11.3mm, 11.5mm, 11.7mm, 11.9mm, 12mm, 12.2mm, 12.4mm, 12.6mm, 12.8mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 16.5mm or 17mm, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0094] Specifically, K can be in a plurality of intervals such as 0.5mm to 0.8mm, 0.5mm to 1.1mm, 0.5mm to 1.3mm, 0.5mm to 1.7mm, 1.7mm to 2mm, 1.5mm to 2mm, 1.1mm to 2mm, 0.9mm to 2mm, 0.7mm to 1.5mm, 0.7mm to 1mm, 0.7mm to 1.3mm, 1.2mm to 1.5mm, and 0.9mm to 1.3mm, and can be selected according to actual conditions. For example, K can be 0.5mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.7mm, 1.9mm, or 2mm, including but not limited to the values ​​listed above, and other values ​​in the above intervals are still applicable and are not specifically limited here.

[0095] See also Figures 4 to 8In the embodiment of the present application, the first connection portion 31 further has a third surface b3 that is opposite to the first surface b1, and each second connection portion 32 has a second surface b2 and a fourth surface b4 on both sides in the thickness direction Z of the pole 30. The second surface b2 and the first surface b1 are located on the same side of the pole 30 in the thickness direction Z, and the third surface b3 and the fourth surface b4 are both located on the other side of the pole 30 in the thickness direction Z. The second surface b2 protrudes from the first surface b1 of the first connection portion 31 in the thickness direction Z of the pole 30, and the third surface b3 protrudes from the fourth surface b4 of the second connection portion 32 in the thickness direction Z of the pole 30. That is, on the side of the pole 30 away from the cover plate 10, the first connection part 31 protrudes from each second connection part 32; on the side of the pole 30 facing the cover plate 10, each second connection part 32 protrudes from the first connection part 31, so that the pole 30 forms a structure in which each second connection part 32 sinks toward the cover plate 10 relative to the first connection part 31 as a whole, so that the pole 30 can be prepared by a stamping process, that is, a stamping process such as piercing and deep drawing can be used to stamp the plate, so as to form the first connection part 31 and each second connection part 32 that sinks as a whole relative to the first connection part 31 on the plate. Compared with the cutting process of removing materials in the prior art, the process cost and material cost are greatly reduced.

[0096] In the present embodiment, the first connection portion 31 and each second connection portion 32 of the pole 30 are integrally formed, for example, by stamping. That is to say, the first connection portion 31 and each second connection portion 32 of the pole 30 are a stamping integrally formed structure. In this way, compared with the cutting process of removing materials in the prior art, the use of a stamping process to form the pole 30 is more adaptable to mass production, improving production efficiency and processing costs; on the other hand, it greatly reduces the waste of materials of the pole 30 and reduces the material cost of the pole 30. It should be noted that in other embodiments, other integral forming processes may also be used, such as a die-casting integral forming process or a 3D printing integral forming process, which are not specifically limited here.

[0097] In the embodiment of the present application, in the process of forming the pole 30 by the stamping process, the corresponding area of ​​the second connection part 32 formed on the plate includes a first area 321 and a second area 322 surrounding the first area 321. The second area 322 of the second connection part 32 is connected to the first connection part 31. The first area 321 of the second connection part 32 is drawn once or multiple times by the drawing process, so that the first area 321 of the second connection part 32 protrudes relative to the second area 322 along the thickness direction Z of the pole 30 to form a connecting sub-portion 324. Among them, the side surface of the second area 322 in the thickness direction Z of the pole 30 away from the cover plate 10 is the above-mentioned fourth surface b4. The second area 322 has a fifth surface b5 away from the above-mentioned fourth surface b4, that is, the side surface of the second area 322 away from the cover plate 10 is the fourth surface b4, and the side surface of the second area 322 facing the cover plate 10 is the fifth surface b5. The distance between the fourth surface b4 and the fifth surface b5 is the thickness dimension of the second area 322. The surface of the connecting sub-portion 324 on one side away from the second region 322 in the thickness direction Z of the pole 30 is the second surface b2, and the pole lug 302 is welded and fixed on the second surface b2 of the connecting sub-portion 324. In this way, the first region 321 of the second connecting portion 32 can be stretched once or multiple times by a stamping process, so that the first region 321 protrudes toward the cover plate 10 relative to the second region 322 to form the connecting sub-portion 324, and the connecting sub-portion 324 is penetrated through the first through hole 11 on the cover plate 10, and then welded and fixed to the corresponding pole lug 302.

[0098] It should be noted that the tab 302 can be welded to the second surface b2 of the connecting sub-part 324 by a welding process, such as laser welding, resistance welding, ultrasonic welding, pressure fusion welding, etc. Alternatively, the tab 302 can be bonded and fixed to the second surface b2 of the connecting sub-part 324 by a conductive adhesive.

[0099] In this embodiment, the tab 302 is welded and fixed on the second surface b2 of the connecting sub-portion 324 by pressure fusion welding. Furthermore, a protrusion 34 is provided on the second surface b2 of the connecting sub-portion 324. During pressure fusion welding, the tab 302 contacts the protrusion 34 on the second surface b2. Since the flow area at the protrusion 34 is small and the heat generation is large, the protrusion 34 on the second surface b2 is melted and the tab 302 is welded and fixed on the second surface b2.

[0100] Specifically in the embodiment, the pole 30 further includes a transition portion 33, and each second connection portion 32 is connected to the first connection portion 31 through the transition portion 33. The end of the transition portion 33 connected to the second connection portion 32 is the first end, and the first end at least partially protrudes from the first surface b1 of the first connection portion 31 along the thickness direction Z of the pole 30. That is, the transition portion 33 extends obliquely from the end connected to the first connection portion 31 to the end connected to the second connection portion 32 relative to the thickness direction Z of the pole 30, so that the fifth surface b5 of the second area 322 protrudes from the first surface b1 of the first connection portion 31 in the thickness direction Z of the pole 30, that is, the second area 322 of the second connection portion 32 sinks as a whole relative to the first connection portion 31, thereby making the protrusion degree of the connection sub-portion 324 relative to the first connection portion 31 greater, which is conducive to reducing the drawing depth of the connection sub-portion 324, reducing the drawing difficulty, and improving the drawing quality of the pole 30.

[0101] Furthermore, the transition portion 33 is configured to be the first to be melted when the battery cell 1 has thermal runaway, that is, the transition portion 33 is melted earlier than the first connection portion 31 and the second connection portion 32. Specifically in this embodiment, the flow area of ​​the transition portion 33 is smaller than the flow area of ​​the first connection portion 31, and smaller than the flow area of ​​the second connection portion 32. The flow area refers to the minimum area when the fluid passes through a certain section. Here, the flow area of ​​the transition portion 33 refers to the surface area of ​​the transition portion 33 perpendicular to the current flow direction, that is, the minimum cross-sectional area of ​​the transition portion 33; similarly, the flow area of ​​the first connection portion 31 and the second connection portion 32 refers to the surface area of ​​the first connection portion 31 and the second connection portion 32 perpendicular to the current flow direction, that is, the minimum cross-sectional area of ​​the first connection portion 31 and the second connection portion 32. In this way, when an abnormality occurs in the circuit during actual use, due to the small flow area of ​​the transition portion 33, the temperature at the transition portion 33 rises quickly, and the transition portion 33 can be quickly melted, thereby cutting off the circuit in time, greatly improving the safety of the battery. It is understandable that the transition portion 33 can reduce the flow area by slotting, opening and / or thinning to ensure that the circuit can be cut off by fusing in time when the circuit is abnormal. The thinning structure can be a structure that thins the thickness of the transition portion 33 as a whole, or a groove structure that is formed in a part of the transition portion 33 and thins the transition portion 33 locally.

[0102] Please continue to see Figures 4 to 8 Further, the connecting sub-portion 324 has a first groove 323, the notch of the first groove 323 passes through the end of the connecting sub-portion 324 away from the second surface b2, so that the connecting sub-portion 324 has a hollow structure, which is conducive to reducing the weight of the pole 30 and saving the material of the pole 30. It can be understood that in the process of drawing the plate once or multiple times using the mold, the first area 321 of the plate is convex to one side relative to the second area 322 as a whole, thereby forming a hollow connecting sub-portion 324.

[0103] In this embodiment, the depth dimension D2 of the first groove 323 is 1 mm to 5 mm. In this way, if the depth of the first groove 323 is too shallow, the second surface b2 of the connecting sub-part 324 will be far away from the battery cell 301, requiring a longer pole ear 302; if the depth of the first groove 323 is too deep, it will make the drawing process more difficult. In this embodiment, by reasonably designing the depth dimension of the first groove 323, the depth dimension of the first groove 323 is moderate, which can not only realize the welding of the pole ear 302 and the second surface b2 of the connecting sub-part 324 without lengthening the pole ear 302, but also reduce the difficulty of the drawing process, improve production efficiency and the yield rate of the pole 30.

[0104] Specifically, D2 can be in multiple ranges such as 1mm-3mm, 1mm-4mm, 3mm-5mm, 2mm-5mm, 2mm-4mm, 1mm-2.5mm and 2.5mm-5mm, and can be selected according to actual conditions. For example, D2 can be 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm, etc., including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0105] In this embodiment, the width dimension W4 of the notch of the first groove 323 in the first preset direction X is 4 mm to 25 mm, the width dimension W5 of the groove bottom of the first groove 323 in the first preset direction X is 2 mm to 20 mm, and W5<W4. In this way, the first groove 323 is designed to have a wide notch and a narrow groove bottom, and the specific values ​​of the notch width and the groove bottom width are reasonably designed, so as to optimize the flow of materials during the drawing process, improve the drawing quality, and greatly reduce the risk of wrinkles at the corners.

[0106] Specifically, W4 can be in multiple ranges such as 4mm~9mm, 4mm~14mm, 4mm~19mm, 4mm~23mm, 20mm~25mm, 15mm~25mm, 10mm~25mm, 7mm~25mm, 5mm~15mm, 5mm~10mm, 10mm~15mm, 7mm~12mm and 8mm~18mm, and the specific selection can be made according to actual situation. For example: W4 can be 4mm, 4.5mm, 5mm, 5.2mm, 5.4mm, 5.6mm, 5.8mm, 6mm, 6.3mm, 6.5mm, 6.7mm, 6.9mm, 7mm, 7.2mm, 7.4mm, 7.6mm, 7.8mm, 8mm, 8.3mm, 8.5mm, 8. 9mm, 9mm, 9.2mm, 9.4mm, 9.6mm, 9.8mm, 10mm, 10.3mm, 10.5mm, 10.7mm, 10.9mm, 11mm, 11.2mm, 11.4mm, 11.6mm, 11.8mm, 12mm, 12.3mm, 12.5mm, 12. 7mm, 12.9mm, 13mm, 13.2mm, 13.4mm, 13.6mm, 13.8mm, 14mm, 14.3mm, 14.5mm, 14.7mm, 14.9mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, 20mm, 20.5mm, 21mm, 21.5mm, 22mm, 22.5mm, 23mm, 23.5mm, 24mm, 24.5mm or 25mm, etc., including but not limited to the listed values, other values ​​within the above range are still applicable and are not specifically limited herein.

[0107] Specifically, W5 can be in multiple ranges such as 2mm-7mm, 2mm-13mm, 2mm-18mm, 2mm-13mm, 15mm-20mm, 10mm-20mm, 5mm-20mm, 2mm-11mm, 11mm-20mm, 3mm-8mm and 7mm-15mm, and can be selected according to actual conditions. For example: W5 can be 2mm, 2.5mm, 3mm, 3.2mm, 3.4mm, 3.6mm, 3.8mm, 4mm, 4.5mm, 5mm, 5.2mm, 5.4mm, 5.6mm, 5.8mm, 6mm, 6.3mm, 6.5mm, 6.7mm, 6.9mm, 7mm, 7.2mm, 7.4mm, 7.6mm, 7.8mm, 8mm, 9 mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, or 20 mm, etc., including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0108] Specifically in this embodiment, the connecting sub-portion 324 has an annular side wall 3245 and a bottom wall 3247. One end of the annular side wall 3245 is connected to the second area 322. The bottom wall 3247 is connected to the other end of the annular side wall 3245, and the end surface of the bottom wall 3247 facing away from the annular side wall 3245 is the above-mentioned second surface b2. The annular side wall 3245 and the bottom wall 3247 are enclosed together to form the above-mentioned first groove 323. In the direction from the second area 322 to the bottom wall 3247, the outer contour size of the annular side wall 3245 is gradually reduced or stepped, so that the connecting sub-portion 324 is in a shape of large at the top and small at the bottom, which is conducive to deep drawing and reduces the difficulty of processing; on the other hand, it makes it easy to insert the connecting sub-portion 324 into the corresponding first through hole 11 on the cover plate 10 during assembly, reducing the difficulty of assembly; on the other hand, the opening range of the first through hole 11 is relatively small, so that the structural strength of the cover plate 10 can be significantly reduced due to the opening.

[0109] See also Fig.10In this embodiment, the angle between the inner surface of the annular side wall 3245 and an imaginary axis C is α, and the imaginary axis C is parallel to the thickness direction of the pole 30. The angle between the outer surface of the annular side wall 3245 and the imaginary axis C is β. Wherein α=β. α can be 5°~60° and / or β can be 5°~60°. In this way, by reasonably designing the specific values ​​of the angles α and β, the inclination of the annular side wall 3245 is moderate, which is convenient for improving the material flow during the drawing process, improving the drawing quality, and greatly reducing the risk of wrinkles at the corners. In other embodiments, α and β may also be unequal.

[0110] Specifically, α can be in multiple intervals such as 5°~15°, 5°~25°, 5°~35°, 5°~45°, 5°~55°, 50°~60°, 40°~60°, 30°~60°, 20°~60°, 10°~60°, 15°~60°, 20°~50°, 30°~40°, 30°~50°, 50°~60° and 15°~45°, and the specific selection can be based on actual conditions. For example, α can be: 5°, 7°, 9°, 11°, 13°, 15°, 17°, 19°, 20°, 22°, 24°, 26°, 28°, 30°, 33°, 35°, 37°, 39°, 40°, 42°, 44°, 46°, 48°, 50°, 53°, 57°, 59° or 60°, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0111] Specifically, β can be in multiple intervals such as 5°~15°, 5°~25°, 5°~35°, 5°~45°, 5°~55°, 50°~60°, 40°~60°, 30°~60°, 20°~60°, 10°~60°, 15°~60°, 20°~50°, 30°~40°, 30°~50°, 50°~60° and 15°~45°, and the specific selection can be based on actual conditions. For example, α can be: 5°, 7°, 9°, 11°, 13°, 15°, 17°, 19°, 20°, 22°, 24°, 26°, 28°, 30°, 33°, 35°, 37°, 39°, 40°, 42°, 44°, 46°, 48°, 50°, 53°, 57°, 59° or 60°, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0112] Furthermore, the thickness dimension of the first connection portion 31 is T9, the thickness dimension of the transition portion 33 is T13, the thickness dimension of the second region 322 is T11, the thickness dimension of the annular side wall 3245 is T14, and the thickness dimension of the bottom wall 3247 is T12, and the following conditions are satisfied: T9 ≥ T12 ≥ T11 > T13 > T14. Furthermore, T12 and T11 satisfy: T12-T11=0~2 / 3×T11. In this way, by reasonably designing the thickness dimensions of each part of the pole 30, the material flow during the drawing process can be further optimized, the drawing difficulty can be reduced, and the production efficiency and yield can be improved.

[0113] Specifically, T12-T11 can be in multiple intervals such as 0~1 / 6×T11, 0~1 / 3×T11, 0~1 / 2×T11, 1 / 2×T11~2 / 3×T11, 1 / 3×T11~2 / 3×T11, 1 / 6×T11~2 / 3×T11, 1 / 6×T11~1 / 2×T11, 1 / 6×T11~1 / 3×T11 and 1 / 3×T11~1 / 2×T11, and the specific selection can be made according to actual situation. For example, T12-T11 can be 1 / 12×T11, 1 / 6×T11, 1 / 4×T11, 1 / 3×T11, 5 / 12×T11, 1 / 2×T11, 7 / 12×T11 or 2 / 3×T11, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0114] In this embodiment, the first connection part 31 needs to be welded to the electrical connector, and the second connection part 32 needs to be welded to the tab through the bottom wall 3247, so the thickness of the first connection part 31 and the bottom wall 3247 is thicker than other parts to provide sufficient penetration. The thickness dimension T9 of the first connection part 31 is 2mm to 8mm, and the thickness dimension T12 of the bottom wall 3247 is greater than or equal to 1.2mm. Accordingly, the thickness dimension T14 of the annular side wall 3245 of each connection sub-part 324 is greater than or equal to 0.5mm.

[0115] Specifically, T9 can be in multiple ranges such as 2mm-4mm, 2mm-6mm, 6mm-8mm, 4mm-8mm, 3mm-7mm, 4mm-6mm, 3mm-5mm and 4mm-7mm, and can be selected according to actual conditions. For example, T9 can be 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm , 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6mm, 6.1mm, 6.2mm, 6.3mm, 6.4mm, 6.5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7mm, 7.1mm, 7.2mm, 7.3mm, 7.4mm, 7.5mm, 7.6mm, 7.7mm, 7.8mm, 7.9mm or 8mm, including but not limited to the listed values, other values ​​within the above range are still applicable and are not specifically limited herein.

[0116] Specifically, T12 can be in multiple ranges such as 1.2mm-2mm, 1.2mm-4mm, 2mm-6mm, 6mm-8mm, 4mm-8mm, 2mm-8mm, 3mm-7mm, 4mm-6mm, 3mm-5mm and 4mm-7mm, and can be selected according to actual conditions. For example: T9 can be 1.2mm, 1.4mm, 1.6mm, 1.8mm , 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3. 5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm , 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6mm, 6.1mm, 6.2mm, 6.3mm, 6.4mm, 6.5mm, 6.6mm, 6.7mm, 6.8mm, 6.9mm, 7mm, 7.1mm, 7.2mm, 7.3mm, 7.4mm, 7.5mm, 7.6mm, 7.7mm, 7.8mm, 7.9mm or 8mm, including but not limited to the listed values, other values ​​within the above range are still applicable and are not specifically limited herein.

[0117] Specifically, T14 can be in multiple ranges such as 0.5mm-1.5mm, 0.5mm-2.5mm, 0.5mm-3.5mm, 0.5mm-4.5mm, 0.5mm-6mm, 4.5mm-6mm, 3mm-6mm, 1mm-6mm, 1mm-5mm, 2mm-4mm, 0.5mm-3mm, 3mm-6mm and 2mm-4mm, and the specific selection can be made according to actual conditions. For example: T14 can be 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm , 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm or 6mm, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0118] It should also be noted that the thickness of the second region 322 located on the side of the connecting sub-portion 324 away from the first connecting portion 31 may be equal to or unequal to the thickness of the connecting sub-portion 324 located on the side close to the first connecting portion 31, which is not limited here. Similarly, the thickness of the annular side wall 3245 located on the side of the first groove 323 away from the first connecting portion 31 may be opposite to or unequal to the thickness of the first groove 323 located on the side close to the first connecting portion 31, which is not limited here.

[0119] The positive electrode 30 is generally formed of aluminum and can be directly welded to the positive electrode of the battery cell assembly. Since the positive electrode is made of the same material as the positive electrode of the battery cell assembly, the welding effect between the positive electrode and the positive electrode can be improved.

[0120] See also Fig. 9 and Fig.10As shown, the pole 30 as the negative pole includes a first metal layer A and a second metal layer B stacked along the thickness direction Z of the pole 30. The first metal layer A and the second metal layer B both extend to the first connection portion 31, each transition portion 33 and each second connection portion 32. The surface of the first metal layer A on the side away from the second metal layer B includes the third surface b3 and the fourth surface b4 mentioned above, and the surface of the second metal layer B on the side away from the first metal layer A is the sixth surface, and the sixth surface includes the first surface b1 and the second surface b2 mentioned above. In other words, the second metal layer B is located on the side of the first metal layer A facing the battery cell assembly 300, so that the second surface b2 is the second metal layer B, that is, the pole ear 302 is welded on the second metal layer B at the second surface b2; the third surface b3 of the first connection portion 31 is the first metal layer A, that is, the electrical connector is welded on the first metal layer A at the third surface b3.

[0121] In this way, the pole 30 is prepared by using a composite plate to ensure that the pole lug 302 is welded on the second metal layer B at the connecting sub-portion 324. The second metal layer B can be made of the same material as the corresponding pole lug 302, or a material that is easy to weld with the corresponding pole lug 302, to ensure the welding quality between the pole lug 302 and the second surface b2 of the connecting sub-portion 324. Similarly, the pole 30 is prepared by using a composite plate to ensure that the electrical connector is welded on the first metal layer A at the first connecting portion 31. The first metal layer A can be made of the same material as the electrical connector, or a material that is easy to weld with the electrical connector, to ensure the welding quality between the electrical connector and the third surface b3 of the first connecting portion 31. More specifically, in this embodiment, the first metal layer is an aluminum layer, the second metal layer is a copper layer, and the pole 30 is made of a copper-aluminum composite plate through a stamping process. Since the material of the negative pole lug of the battery cell assembly is generally copper, the second metal layer B is the same material as the negative pole lug, which can improve the welding effect between the negative pole column and the negative pole lug.

[0122] Specifically in this embodiment, the thickness of the second metal layer B at the first connection portion 31 is T2, the thickness of the second metal layer B at the second region 322 is T3, the thickness of the second metal layer B at the bottom wall 3247 is T5, the thickness of the second metal layer B at the annular side wall 3245 is T7, and the thickness of the second metal layer B at the transition portion 33 is T8. Among them, T2, T3, T5, T7 and T8 satisfy: T7<T8<T3≤T5≤T2. Further, T5, T3 and T2 satisfy: T5-T3=0~0.5×T2.

[0123] Specifically, T5-T3 can be in multiple ranges such as 0~0.1×T2, 0~0.2×T2, 0~0.3×T2, 0~0.4×T2, 0.4×T2~0.5×T2, 0.3×T2~0.5×T2, 0.2×T2~0.5×T2, 0.05×T2~0.45×T2, 0.1×T2~0.4×T2 and 0.15×T2~0.35×T2, and the specific selection can be based on actual conditions. For example, T5-T3 can be 0.1×T2, 0.12×T2, 0.14×T2, 0.16×T2, 0.18×T2, 0.2×T2, 0.23×T2, 0.25×T2, 0.27×T2, 0.29×T2, 0.3×T2, 0.32×T2, 0.34×T2, 0.36×T2, 0.38×T2, 0.4×T2, 0.42×T2, 0.44×T2, 0.46×T2, 0.48×T2 or 0.5×T2, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0124] In this embodiment, the thickness T5 of the second metal layer B at the bottom wall 3247 is 0.3 mm to 1.8 mm. In this way, the penetration depth when the tab 302 is welded to the second surface b2 of the bottom wall 3247 is ensured to be less than the thickness T5 of the second metal layer B at the bottom wall 3247, thereby preventing the molten pool from entering the first metal layer A and causing welding defects such as explosion points, thereby further improving the welding quality.

[0125] Specifically, T5 can be in multiple ranges such as 0.3mm~0.6mm, 0.3mm~0.9mm, 0.3mm~1.2mm, 0.3mm~1.5mm, 0.3mm~1.6mm, 1.5mm~1.8mm, 1.2mm~1.8mm, 0.9mm~1.8mm, 0.6mm~1.8mm, 0.6mm~1.5mm, 0.6mm~1.3mm, 0.9mm~1.2mm and 0.8mm~1.1mm, and the specific selection can be made according to actual conditions. For example, T5 can be 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm or 1.8mm, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0126] In other embodiments, the thickness T5 of the second metal layer B at the bottom wall 3247 accounts for 10% to 40% of the thickness T12 of the bottom wall 3247. In this way, the penetration depth when the tab 302 is welded to the second surface b2 of the bottom wall 3247 is ensured to be less than the thickness T5 of the second metal layer B at the bottom wall 3247, thereby preventing the molten pool from entering the first metal layer A and causing welding defects such as explosion points, thereby further improving the welding quality.

[0127] Specifically, the ratio range may be 10% to 15%, 10% to 25%, 10% to 35%, 35% to 40%, 25% to 40%, 15% to 40%, 15% to 35%, 20% to 30%, 15% to 25%, 20% to 35%, etc., and may be selected according to actual conditions. For example, the ratio may be 12%, 14%, 16%, 18%, 20%, 23%, 25%, 27%, 29%, 30%, 32%, 34%, 36%, 38% or 40%, etc., including but not limited to the listed values, and other values ​​within the above ranges are still applicable and are not specifically limited here.

[0128] The thickness T3 of the second metal layer B at the second region 322 is 0.05 mm to 1.5 mm. Specifically, T3 may be in a range of 0.05 mm to 0.3 mm, 0.05 mm to 0.6 mm, 0.05 mm to 0.9 mm, 0.05 mm to 1.2 mm, 1.2 mm to 1.5 mm, 0.9 mm to 1.5 mm, 0.6 mm to 1.5 mm, 0.3 mm to 1.5 mm, 0.75 mm to 1.3 mm, 0.1 mm to 1 mm, 0.1 mm to 0.8 mm, 0.2 mm to 0.6 mm, 0.3 mm to 0.5 mm, etc., and may be selected according to actual conditions. For example, T3 can be 0.05mm, 0.25mm, 0.75mm, 0.95mm, 0.10mm, 0.15mm, 0.20mm, 0.25mm, 0.30mm, 0.35mm, 0.40mm, 0.45mm, 0.50mm, 0.55mm, 0.60mm, 0.65mm, 0.70mm, 0.75mm, 0.80mm, 0.85mm, 0.90mm, 0.95mm, 1.00mm, 1.10mm, 1.20mm, 1.30mm, 1.40mm or 1.50mm, including but not limited to the listed values. Other values ​​within the above range are still applicable and are not specifically limited here.

[0129] In other embodiments, the thickness T3 of the second metal layer B at the second region 322 accounts for 10% to 40% of the thickness T11 of the second region 322. Specifically, the ratio range can be 10% to 15%, 10% to 25%, 10% to 35%, 35% to 40%, 25% to 40%, 15% to 40%, 15% to 35%, 20% to 30%, 15% to 25% and 20% to 35%, etc., which can be selected according to actual conditions. For example: the ratio can be 12%, 14%, 16%, 18%, 20%, 23%, 25%, 27%, 29%, 30%, 32%, 34%, 36%, 38% or 40%, including but not limited to the listed values, and other values ​​in the above ranges are still applicable and are not specifically limited here.

[0130] Specifically in this embodiment, at the second region 322, a second interface E is formed between the first metal layer A and the second metal layer B. In the thickness direction Z of the pole 30, the second interface E protrudes from the first surface b1 of the first connecting portion 31, so that the overall sinking distance of the second connecting portion 32 relative to the first connecting portion 31 is sufficiently large, thereby reducing the drawing depth of the connecting sub-portion 324 as much as possible, reducing the drawing difficulty, and improving the drawing quality.

[0131] Furthermore, the height difference h between the second interface E and the first surface b1 in the thickness direction of the pole 30 is 0.02mm-1mm, and the height difference can be 0.1mm-0.5mm. It should be noted that the height difference h is negatively correlated with the thickness of the cover plate 10 in the second area 322, that is, the greater the height difference h, the thinner the thickness of the cover plate 10 in the second area 322; the smaller the height difference h, the thicker the thickness of the cover plate 10 in the second area 322. In this embodiment, the height difference h is designed within a suitable range, that is, the distance of the overall sinking of the second connection part 32 relative to the first connection part 31 is limited within a suitable range, which can avoid the portion of the cover plate 10 corresponding to the second area 322 being compressed and deformed due to being too thin.

[0132] It should be noted that h can be 0.02 mm, 0.04 mm, 0.06 mm, 0.08 mm or 0.10 mm, etc., and is not particularly limited here.

[0133] It should also be noted that the second metal layer B is not limited to extending to each second connection portion 32, each transition portion 33 and the first connection portion 31. In other embodiments, see Figure 7 and Figure 8As shown, only the second metal layer B is provided at each second connection portion 32, and only the first metal layer A is provided at each transition portion 33 and the first connection portion 31 without the second metal layer B. That is, the pole 30 has only the first metal layer A at the first connection portion 31 and each transition portion 33, and the pole 30 has the first metal layer A and the second metal layer B at each second connection portion 32. That is, the second connection portion 32 is still a double-layer structure, and the transition portion 33 and the first connection portion 31 are not required to be welded with the negative electrode ear, so the whole is an aluminum structure, that is, the position where copper is provided in the first connection portion 31 in the previous embodiment is replaced with aluminum. Thus, on the one hand, since the overall material of the first connection part 31 is the same as that of the electrical connection part, for example, both are aluminum, it can improve the welding quality between the electrical connection part and the third surface b3 of the first connection part 31, and improve the welding quality between the pole ear 302 and the second surface b2 of the second connection part 32; on the other hand, it also greatly reduces the area of ​​the interface formed between the first metal layer A and the second metal layer B. Since the bonding force at the interface between the first metal layer A and the second metal layer B is large, it has an adverse effect on stamping, so the reduction of the interface area can greatly reduce the adverse effect of the interface on stamping, which is conducive to reducing the difficulty of stamping and improving the stamping quality; on the other hand, the first metal layer A is made of aluminum and the second metal layer B is made of copper, which can save the amount of copper to reduce the cost on the basis of ensuring the structural strength of the pole 30. In other embodiments, the position where the copper is set in the first connection part 31 in the previous embodiment can also be missing, so that the overall thickness of the pole 30 can be reduced to a certain extent.

[0134] In other embodiments, the second metal layer B is only provided at each second connection portion 32, including at least the following situations: (1) the second metal layer B is located on the bottom wall 3247, and the area of ​​the second metal layer B located on the bottom wall 3247 can be adjusted according to the welding area of ​​the negative electrode ear and the bottom wall 3247, that is, the side of the bottom wall 3247 facing the inside of the battery cell can be entirely composed of the second metal layer B, or can be partially composed of the second metal layer B, as long as the welding effect of the negative electrode ear and the bottom wall 3247 can be guaranteed; (2) the second metal layer B is located on the bottom wall 3247 and extends to the annular side wall 3245; (3) the second metal layer B is located on the bottom wall 3247 and extends to the annular side wall 3245 and the second area 322.

[0135] Furthermore, the transition portion 33 has a seventh surface b7, and the seventh surface b7 and the sixth surface b6 are located on the same side of the pole 30 in the thickness direction Z, that is, the surface of the transition portion 33 facing the cover plate 10 is the seventh surface b7. The seventh surface b7 and the sixth surface b6 are transitioned by an arc segment 332. Please refer to Figure 8The second metal layer B has a first interface D at one end close to the first connection portion 31, and there is a preset distance L between the first interface D and the arc segment 332. In this way, a preset distance L is reserved between the first interface D and the arc segment 332 at the corner to prevent the first interface D of the second metal layer B from extending to the corner and causing adverse effects on the flow of materials during stamping, which is conducive to reducing the difficulty of stamping and improving the stamping quality.

[0136] In this embodiment, the preset distance L satisfies: 0.5 mm ≤ L ≤ 6 mm. In this way, the preset distance L is designed within a suitable range so that the preset distance L is not too large, which avoids waste of the pole 30 material on the one hand, and avoids the area of ​​the place being too large to occupy the area of ​​the first connection part 31 and the second connection part 32 on the other hand, thereby causing the area of ​​the second surface b2 welded to the pole ear 302 and / or the third surface b3 welded to the electrical connector to be too small.

[0137] Specifically, the preset distance L can be in a range of 0.5mm≤L≤2mm, 0.5mm≤L≤4mm, 4mm≤L≤6mm, 2mm≤L≤6mm, 2.0mm≤L≤6mm, and 3.0mm≤L≤5mm, etc., and can be selected according to actual conditions. For example, the preset distance L can be 0.5mm, 0.7mm, 0.9mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm , 2mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm, 4.9mm, 5mm, 5.1mm, 5.2mm, 5.3mm, 5.4mm, 5.5mm, 5.6mm, 5.7mm, 5.8mm, 5.9mm, 6mm, etc., including but not limited to the listed values, other values ​​within the above range are still applicable and are not specifically limited herein.

[0138] It should be noted that, as an embodiment, the material of the electrical connector may be aluminum, and in order to ensure the welding quality between the electrical connector and the third surface b3 of the first connecting portion 31, the first metal layer A may also be an aluminum layer. Similarly, the material of the tab 302 may be copper, and in order to ensure the welding quality between the tab 302 and the second surface b2 of the connecting sub-portion 324, the second metal layer B may also be a copper layer.

[0139] It should also be noted that the pole 30 is not limited to being prepared using a composite plate material, that is, the pole 30 is not limited to having a first metal layer A and a second metal layer B. In other embodiments, the pole 30 serving as a positive pole may also have only a first metal layer A, without having a second metal layer B. For example, when the material of the electrical connector is aluminum and the material of the pole lug 302 is also aluminum, the pole 30 may have only a first metal layer A, and the first metal layer A is an aluminum layer. In addition, in a sodium-ion battery, the material of the positive pole lug and the negative pole lug may both be aluminum, and correspondingly, the material of the positive pole column and the negative pole column may also be aluminum, that is, in some battery types, the positive pole column and the negative pole column may both have only a first metal layer A, without having a second metal layer B.

[0140] As an embodiment, when the material of the positive electrode ear is aluminum and the material of the negative electrode ear is copper, the positive electrode column adopts a structure having only the first metal layer A (without the second metal layer B), while the negative electrode column adopts a structure having the first metal layer A and the second metal layer B.

[0141] See also Figure 1 , Figure 2 and Figure 7 In the embodiment of the present application, the top cover assembly 100 further includes a first insulating member 20, at least part of which forms insulation between the cover plate 10 and the pole 30. The first insulating member 20 can be firstly injection molded with the pole 30 and then assembled with the cover plate 10 as a whole; or the pole 30 can be first assembled with the cover plate 10 and then integrally injection molded to obtain the first insulating member 20.

[0142] Specifically, the first insulating member 20 includes a first insulating portion 21 and a second insulating portion 22. The first insulating portion 21 is arranged between the first connecting portion 31 and the cover plate 10 to form insulation, thereby preventing the cover plate 10 from being charged or short-circuited. The second insulating portion 22 covers each second connecting portion 32 and each transition portion 33. On the one hand, the surface of each second connecting portion 32 and each transition portion 33 is insulated and protected; on the other hand, the creepage distance from the transition portion 33 to the third surface b3 of the pole 30 can be increased, and the electrical clearance between the transition portion 33 and the electrical connector can be increased after welding the electrical connector; on the third hand, the overall strength of the pole 30 is increased, greatly reducing the risk of deformation of the pole 30.

[0143] Specifically in the embodiment, at least one second through hole 330 is formed on the transition portion 33 (see Figure 4 ), the first insulating member 20 further includes a third insulating portion 23 filled in the second through hole 330 (see Fig.12), the third insulating part 23 is connected to the first insulating part 21 and the second insulating part 22. The first insulating part 21, the second insulating part 22 and the third insulating part 23 are integrally injection molded. In this way, during the injection molding, the molten injection molding material is injected into the surface of each second connecting part 32, and a part of the injection molding material covers the surface of each second connecting part 32 and each transition part 33, and forms the second insulating part 22 after solidification; the other part of the injection molding material flows into the space between the first connecting part 31 and the cover plate 10 from the second through hole 330, and forms the third insulating part 23 in the second through hole 330 after solidification, and forms the first insulating part 21 between the first connecting part 31 and the cover plate 10. The third insulating part 23 filled in the second through hole 330 can make up for the structural strength lost by the transition part 33 due to the formation of the second through hole 330, and avoid the structural strength of the pole 30 being too low. Moreover, the contact area between the first insulating member 20 and the pole 30 can be increased, thereby improving the bonding force between the two.

[0144] It should be noted that the second through hole 330 on the transition portion 33, on the one hand, plays a role in circulating the injection molding material during injection molding, and on the other hand, also plays a role in reducing the flow area of ​​the transition portion 33, ensuring that the transition portion 33 can be melted in time to cut off the circuit when an abnormality occurs.

[0145] Specifically in the embodiment, the top cover assembly 100 further includes a flange portion 12. The flange portion 12 is fixedly connected to the surface of the cover plate 10 on the side facing away from the battery cell assembly 300, and a portion of the flange portion 12 can be bent to the surface of the second insulating portion 22 on the side facing away from the cover plate 10 by a rolling process, so that the second insulating portion 22 and the second connecting portion 32 of the pole 30 are pressed against the cover plate 10 by the flange portion 12 to prevent the pole 30 from being separated from the cover plate 10.

[0146] Furthermore, the second insulating portion 22 has a step surface 223 extending along the peripheral edge thereof. The flange portion 12 extends along the peripheral edge of the second insulating portion 22 and presses against the step surface 223, so that the pressing structure of the flange portion 12 against the second insulating portion 22 is more stable, thereby making the assembly structure of the pole 30 and the cover plate 10 more stable, and preventing the pole 30 from being offset or even separated from the cover plate 10.

[0147] Specifically in the embodiment, a second groove 315 is formed on the first surface b1 of the first connection portion 31, and a third groove 13 is formed on the surface of the cover plate 10 facing the first insulating portion 21. A portion of the first insulating portion 21 is filled in the second groove 315, and a portion of the first insulating portion 21 is also filled in the third groove 13. In this way, when the first insulating member 20 is injection molded, the molten injection material can flow into the second groove 315 and the third groove 13, and after solidification, a structure is formed in which a portion of the first insulating portion 21 is filled in the second groove 315 and the third groove 13.

[0148] Further, at least a portion of the second groove 315 is gradually narrowed or stepped in a direction from the groove bottom to the groove opening, so that the first insulating portion 21 is closely nested in the pole 30 through the second groove 315, and the pole 30 is prevented from being separated from the first insulating member 20. At least a portion of the third groove 13 is gradually narrowed or stepped in a direction from the groove bottom to the groove opening, so that the first insulating portion 21 is closely nested in the cover plate 10 through the third groove 13, and the cover plate 10 is prevented from being separated from the first insulating member 20.

[0149] In this embodiment, the depth dimension of the second groove 315 is H2, and the thickness dimension of the first connection part 31 is T9, and H2 and T9 satisfy: H2 = (5% to 50%) T9. In this way, by designing the depth of the second groove 315 within a suitable range, on the one hand, it is avoided that the depth of the second groove 315 is too shallow, resulting in an insignificant effect of increasing the bonding force between the first insulating part 21 and the first connection part 31; on the other hand, it is avoided that the depth of the second groove 315 is too deep, resulting in a low strength of the first connection part 31 and easy deformation. It should be noted that H2 can be 5%×T9, 10%×T9, 15%×T9, 20%×T9, 25%×T9, 30%×T9, 35%×T9, 40%×T9, 45%×T9 or 50%×T9, etc., and is not specifically limited here.

[0150] It should be noted that the number of the second grooves 315 can be one or more, and is not specifically limited here. When the number of the second grooves 315 is one, the second groove 315 itself is symmetrically arranged on the side surface of the first connection part 31 facing the cover plate 10 relative to the center line of the first connection part 31, so that the force on the pole 30 is more balanced, and the pole 30 is prevented from warping or cracking due to uneven force. When the number of the second grooves 315 is more than one, the multiple second grooves 315 are symmetrically arranged on the side surface of the first connection part 31 facing the cover plate 10 relative to the center line of the first connection part 31, so that the force on the pole 30 is more balanced, and the pole 30 is prevented from warping or cracking due to uneven force.

[0151] In this embodiment, the depth dimension of the third groove 13 is H3, and the thickness dimension of the cover plate 10 is H4, and H3 and H4 satisfy: H3 = (5% to 50%) H4. In this way, by designing the depth of the third groove 13 within a suitable range, on the one hand, it is avoided that the depth of the third groove 13 is too shallow, resulting in the effect of increasing the bonding force between the first insulating part 21 and the cover plate 10 is not obvious; on the other hand, it is avoided that the depth of the third groove 13 is too deep, resulting in the cover plate 10 being weak in strength and easy to deform. It should be noted that H3 can be 5%×H4, 10%×H4, 15%×H4, 20%×H4, 25%×H4, 30%×H4, 35%×H4, 40%×H4, 45%×H4 or 50%×H4, etc., and is not specifically limited here.

[0152] It should be noted that the number of the third grooves 13 can be one or more, and is not specifically limited here. When the number of the third grooves 13 is one, the third groove 13 itself is symmetrically arranged on the side surface of the cover plate 10 facing the first insulating portion 21 relative to the center line of the cover plate 10, so that the cover plate 10 is subjected to more uniform force, avoiding defects such as warping or cracking of the cover plate 10 due to uneven force. When the number of the third grooves 13 is more than one, the multiple third grooves 13 are symmetrically arranged on the side surface of the cover plate 10 facing the first insulating portion 21 relative to the center line of the cover plate 10, so that the cover plate 10 is subjected to more balanced force, avoiding defects such as warping or cracking of the cover plate 10 due to uneven force.

[0153] Specifically in the embodiment, the second insulating portion 22 is recessed into the first groove 323 to form a fourth groove 225. That is, the second insulating portion 22 covers the inner wall of the first groove 323, but does not fill the entire first groove 323. On the one hand, it is beneficial to improve the bonding force between the second insulating portion 22 and the second connecting portion 32 of the pole 30, and avoid the second insulating portion 22 and the second connecting portion 32 from being separated or misaligned; on the other hand, it reduces the material usage of the second insulating portion 22, and avoids defects such as uneven injection molding due to local excessive thickness.

[0154] Specifically in the embodiment, the first connection portion 31 has a boss 311 and an annular surface 312 on the side opposite to the first surface b1. The annular surface 312 is arranged around the boss 311, and the boss 311 is protruded relative to the annular surface 312 in a direction away from the first surface b1. The electrical connector is welded on the boss 311, and the second insulating portion 22 of the first insulating member 20 is lower than the annular surface 312 or flush with the annular surface 312. In this way, by providing the boss 311, the injection material can be prevented from flowing onto the boss 311 during injection molding, resulting in the first insulating member 20 covering the surface of the boss 311.

[0155] In this embodiment, the protrusion height H1 of the boss 311 relative to the annular surface 312 is 0.05 mm to 0.8 mm, and H1 can be in a plurality of ranges such as 0.1 mm to 0.6 mm or 0.3 mm to 0.5 mm. It should be noted that H1 can be 0.05 mm, 0.20 mm, 0.35 mm, 0.50 mm, 0.65 mm or 0.8 mm, etc., and is not particularly limited here.

[0156] Specifically in the embodiment, the top cover assembly 100 further includes a sealing ring 40, which includes a first sealing portion 41 and a second sealing portion 43. The first sealing portion 41 and the second sealing portion 43 are both sleeved on the connecting sub-portion 324, and the first sealing portion 41 is located between the inner wall of the first through hole 11 and the connecting sub-portion 324, and the second sealing portion 43 is located between the surface of the side of the cover plate 10 away from the battery cell assembly 300 and the second area 322. In this way, on the one hand, the sealing ring 40 is used to seal the first through hole 11 on the cover plate 10 to prevent the electrolyte in the housing 200 from leaking out from the first through hole 11; on the other hand, the sealing ring 40 is used to form insulation between the connecting sub-portion 324 and the second area 322 and the cover plate 10 to prevent the pole 30 from being electrically conductive with the cover plate 10.

[0157] For details about the embodiments, please refer to Figure 5 , the second area 322 includes a first straight portion a1, a first arc portion a2, a second straight portion a3 and a second arc portion a4 that are connected in sequence. The first straight portion a1 and the second straight portion a3 are respectively located on both sides of the first area 321 in the first preset direction X, and the first arc portion a2 and the second arc portion a4 are respectively located on both sides of the first area 321 in the second preset direction Y. The curvature radius R of the outer edge of the first arc portion a2 and the outer edge of the second arc portion a4 is 3mm to 8mm, and R can be in a plurality of intervals such as 4mm to 6mm, 3mm to 5mm and 5mm to 8mm, which can be selected according to actual conditions. In this way, the curvature radius R of the outer edge of the first arc portion a2 and the outer edge of the second arc portion a4 is set within a suitable range, on the one hand, to avoid R being too small to cause the flange portion 12 to be unable to be folded onto the second insulating portion 22; on the other hand, to avoid R being too large to cause the arc area of ​​the second area 322 to be too large, thereby avoiding waste of material of the pole 30.

[0158] It should be noted that R can be 3mm, 4mm, 5mm, 6mm, 7mm or 8mm, etc., and is not limited here.

[0159] Specifically in the embodiment, on a virtual plane perpendicular to the thickness direction of the pole 30, the orthographic projection of the first connection part 31 does not overlap with the orthographic projection of each of the second connection parts 32. That is to say, each of the second connection parts 32 is completely staggered with the first connection part 31 in the thickness direction Z of the pole 30, so that the position where the first connection part 31 is welded to the electrical connector is far enough away from each of the second connection parts 32, and then when the electrical connector is welded to the third surface b3 of the first connection part 31, the adverse effect of the heat generated by the welding on the first insulating part 20 and the sealing ring 40 is greatly reduced, which is conducive to reducing the risk of cracking or hot melting of the first insulating part 20 and improving the sealing reliability of the sealing ring 40.

[0160] It should also be noted that the top cover assembly 100 can be assembled by pre-injection molding or integral injection molding. Fig.11 and Fig.12 The method of pre-injection molding refers to: first, forming the pole 30 by a stamping process; then, the first insulating member 20 is injection-molded on the pole 30, so that the pole 30 and the first insulating member 20 form a whole; then, the sealing ring 40 is sleeved on the connecting sub-portion 324 of the pole 30, and the connecting sub-portion 324 of the pole 30 is inserted into the first through hole 11 on the cover plate 10; then, the flange portion 12 is rolled so that part of the flange portion 12 is bent onto the second insulating portion 22 of the first insulating member 20, so that the pole 30 and the first insulating member 20 are pressed tightly on the cover plate 10, and the sealing ring 40 is compressed at the same time, so that the sealing ring 40 seals the first through hole 11.

[0161] In the pre-injection molding method, since the flange portion 12 is rolled to a folded state after the first insulating member 20 is injection-molded, the second insulating portion 22 of the injection-molded first insulating member 20 does not cover the flange portion 12 .

[0162] See also Figure 7 and Fig. 9As shown, the one-piece injection molding method means: first, the pole 30 is formed by a stamping process; then, the sealing ring 40 is sleeved on the connecting sub-portion 324 of the pole 30, and the connecting sub-portion 324 is inserted into the first through hole 11 on the cover plate 10; then, the pole 30, the sealing ring 40 and the cover plate 10 are loaded into the injection mold as a whole for injection molding, so as to injection mold the first insulating member 20 (the flange portion 12 has been rolled when the first insulating member 20 is injection molded), and the pole 30 is pressurized during the process of injection molding the first insulating member 20, so that the pole 30 compresses the sealing ring 40, that is, the sealing ring 40 maintains a certain amount of compression; after the injection molding is completed, the cover plate 10, the sealing ring 40, the pole 30 and the first insulating member 20 are removed from the injection mold as a whole. At this time, the pressure on the pole 30 disappears, but due to the pressing effect of the flange portion 12 on the first insulating member 20, the pole 30 and the first insulating member 20 can remain pressed against the cover plate 10, and the sealing ring 40 can also remain in a compressed state.

[0163] In the integral injection molding method, since the flange portion 12 has been rolled to a folded state before the first insulating member 20 is injection-molded, the second insulating portion 22 of the injection-molded first insulating member 20 also covers the flange portion 12 .

[0164] Considering that the sealing ring 40 is located on the side of the connecting sub-part 324 away from the first connecting part 31, it indirectly bears the pressure from the flange part 12, while the sealing ring 40 is located on the side close to the first connecting part 31. The pressure received is relatively small, and this part will push up the second area 322 located on the side of the connecting sub-part 324 close to the first connecting part 31. Therefore, the thickness dimension of the second area 322 located on the side of the connecting sub-part 324 close to the first connecting part 31 is configured to be greater than the thickness dimension of the second area 322 located on the side of the connecting sub-part 324 away from the first connecting part 31. In this way, the thickness of the second area 322 located on the side of the connecting sub-part 324 close to the first connecting part 31 is increased, thereby increasing the structural strength of this part.

[0165] The pole 30 may also be mounted on the housing 200. The structure of the pole 30 mounted on the housing 200 is similar to that of the pole 30 mounted on the cover plate 10, so it will not be described in detail here.

[0166] Based on the above-mentioned pole 30, the present application also provides a method for processing the pole 30. Fig.13 and Fig.14 As shown, the processing method comprises the following steps: Step 1: Provide a plate 101. Specifically, the thickness of the plate 101 is 2 mm to 8 mm, and the thickness of the plate can be in a plurality of intervals such as 2 mm to 4 mm, 2 mm to 6 mm, 6 mm to 8 mm, 4 mm to 8 mm, 3 mm to 7 mm, and 4 mm to 6 mm, and can be selected according to actual conditions. For example, the thickness of the plate can be 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm, etc., which is not specifically limited here. It can be understood that the plate 101 can be a composite plate including a first metal layer A and a second metal layer B, or a plate including only the first metal layer A.

[0167] In some embodiments, see Fig.13 and Fig.14 The plate 101 may be a local composite plate in which a portion (i.e., a region used to form each second connection portion 32) includes the first metal layer A and the second metal layer B, and the remaining region (i.e., a region used to form the first connection portion 31 and each transition portion 33) does not include the second metal layer B.

[0168] In other embodiments, see Fig.15 The plate 101 may include the first metal layer A and the second metal layer B in all regions, that is, the region of the plate 101 used to form the first connecting portion 31, the regions of each transition portion 33, and the regions of each second connecting portion 32 all include the first metal layer A and the second metal layer B.

[0169] Step 2: Press and draw the plate 101; by pressing the plate 101, a first connection area 102, multiple second connection areas 103 and a transition area 104 between each second connection area 103 and the first connection area 102 are formed on the plate 101; by drawing the plate 101, a first connection part 31 is formed in the first connection area 102, a second connection part 32 is formed in each second connection area 103, and a transition part 33 is formed in each transition area 104.

[0170] Step 3: Punch the plate 101 to obtain the pole 30. Specifically, the thickness dimension T9 of the first connecting portion 31 is 2 mm to 8 mm, the thickness dimension T14 of the annular side wall 3245 of each connecting sub-portion 324 is greater than or equal to 0.5 mm, the thickness dimension T12 of the bottom wall 3247 is greater than or equal to 1.2 mm, and T9≥T12>T14 is satisfied.

[0171] Thus, compared with the cutting process for removing materials in the prior art, in the present application, the plate 101 is processed into a pole 30 through stamping processes such as piercing, drawing and cutting. On the one hand, it is more suitable for mass production, with lower production costs and higher production efficiency; on the other hand, it greatly saves pole materials and reduces material costs.

[0172] It should be noted that in step 2, the number of times of pressing is not limited to one, and the number of times of drawing is not limited to one, and the sheet 101 can be pressed and drawn multiple times. Fig.13 and Fig.14 In the illustrated embodiment, the plate 101 is subjected to one embossing and three drawing in step 2. Of course, the plate 101 may also be punched in step 2 to form holes such as the second through hole 330 on the pole 30. In addition, the embossing, drawing and punching processes may also be performed simultaneously.

[0173] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0174] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be construed as limiting the scope of the patent application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent application shall be subject to the attached claims.

Claims

1. A pole, characterized in that: The invention comprises at least one first connection portion (31) and at least two second connection portions (32), wherein the at least two second connection portions (32) are arranged at intervals along a first preset direction (X), a first connection portion (31) is arranged between each two adjacent second connection portions (32), and each first connection portion (31) is connected to two adjacent second connection portions (32); the first connection portion (31) is used to connect to an electrical connector, and a side surface of the first connection portion (31) in the thickness direction (Z) of the pole is a first surface (b1); each second connection portion (32) protrudes from the first surface (b1) of the first connection portion (31) in the thickness direction (Z) of the pole, and the second connection portion (32) is used to connect to a pole lug.

2. The pole according to claim 1, characterized in that: On a virtual plane perpendicular to the thickness direction (Z) of the pole, the orthographic projection of the first connecting portion (31) does not overlap with the orthographic projections of each of the second connecting portions.

3. The pole according to claim 1, characterized in that: The first connection portion (31) and each of the second connection portions (32) are integrally formed.

4. The pole according to claim 3, characterized in that: The first connection portion (31) and each of the second connection portions (32) are integrally formed by stamping.

5. The pole according to claim 1, characterized in that: The number of the second connection parts (32) is two, and the two second connection parts (32) are respectively connected to two sides of the first connection part (31) in the first preset direction (X).

6. The pole according to claim 5, characterized in that: The distance W2 between the ends of the two second connecting parts (32) that are away from each other is 20 mm-70 mm.

7. The pole according to claim 5, characterized in that: A dimension W6 of each second connection portion (32) in the second preset direction (Y) is 20 mm to 60 mm, and the first preset direction (X), the second preset direction (Y) and the pole thickness direction (Z) are perpendicular to each other.

8. The pole according to claim 1, characterized in that: Each second connection portion (32) has a second surface (b2) on one side in the thickness direction (Z) of the pole, the second surface (b2) and the first surface (b1) are located on the same side of the pole (30) in the thickness direction (Z), and the second surface (b2) protrudes from the first surface (b1) of the first connection portion (31) in the thickness direction (Z) of the pole.

9. The pole according to claim 8, characterized in that: The first connecting portion (31) further comprises a third surface (b3) which is opposite to the first surface (b1), and each of the second connecting portions (32) further comprises a fourth surface (b4) which is opposite to the second surface (b2); The third surface (b3) protrudes from a side of the second connecting portion (32) having the fourth surface (b4) in the thickness direction (Z) of the pole.

10. The pole according to claim 9, characterized in that: Each second connecting portion (32) comprises a first region (321) and a second region (322) surrounding the first region (321), the second region (322) being connected to the first connecting portion (31), and the first region (321) protruding relative to the second region (322) along the thickness direction (Z) of the pole to form a connecting sub-portion (324); A surface of the second region (322) on one side facing away from the connecting sub-portion (324) in the direction of the thickness (Z) of the pole is the fourth surface (b4), and a surface of the connecting sub-portion (324) on one side facing away from the second region (322) in the direction of the thickness (Z) of the pole is the second surface (b2).

11. The pole according to claim 10, characterized in that: The second region (322) has a fifth surface (b5) that is opposite to the fourth surface (b4), and the fifth surface (b5) protrudes from the first surface (b1) of the first connecting portion (31) in the thickness direction (Z) of the pole.

12. The pole according to claim 10, characterized in that: A protrusion (34) is provided on the second surface (b2) of the connecting sub-portion (324).

13. The pole according to claim 10, characterized in that: The connecting sub-portion (324) has a first groove (323), and the notch of the first groove (323) passes through an end of the connecting sub-portion (324) that faces away from the second surface (b2).

14. The pole according to claim 13, characterized in that: In the thickness direction (Z) of the pole, the bottom of the first groove (323) is located on a side of the first surface (b1) away from the third surface (b3).

15. The pole according to claim 13, characterized in that: The depth dimension D2 of the first groove (323) is 1 mm to 5 mm; and / or The width dimension W4 of the notch of the first groove (323) in the first preset direction (X) is 4 mm to 25 mm, the width dimension W5 of the groove bottom of the first groove (323) in the first preset direction (X) is 2 mm to 20 mm, and W5<W4.

16. The pole according to claim 13, characterized in that: The connecting sub-portion (324) comprises a bottom wall (3247) and an annular side wall (3245); one end of the annular side wall (3245) is connected to the second region (322); the bottom wall (3247) is connected to the other end of the annular side wall (3245); the annular side wall (3245) and the bottom wall (3247) together enclose the first groove (323); In the direction from the second area (322) to the bottom wall (3247), the outer contour size of the annular side wall (3245) gradually decreases or decreases in a step-like manner.

17. The pole according to claim 16, characterized in that The angle between the inner surface of the annular side wall (3245) and a virtual axis (C) is α, the virtual axis (C) is parallel to the thickness direction (Z) of the pole, and the angle between the outer surface of the annular side wall (3245) and the virtual axis (C) is β; α is 5° to 60° and / or β is 5° to 60°.

18. The pole according to claim 17, characterized in that α=β。 19. The pole according to claim 16, characterized in that: The thickness dimension of the annular side wall (3245) is T14, the thickness dimension of the bottom wall (3247) is T12, the thickness dimension of the second region (322) is T11, and T12≥T11>T14.

20. The pole according to claim 19, characterized in that T12 and T11 satisfy: T12-T11=0~2 / 3×T11.

21. The pole according to claim 10, characterized in that The second region (322) comprises a first straight portion (a1), a first arc portion (a2), a second straight portion (a3) ​​and a second arc portion (a4) which are connected end to end in sequence, the first straight portion (a1) and the second straight portion (a3) ​​are respectively located on both sides of the first region (321) in the first preset direction (X), the first arc portion (a2) and the second arc portion (a4) are respectively located on both sides of the first region (321) in the second preset direction (Y), and the first preset direction (X), the second preset direction (Y) and the pole thickness direction (Z) are perpendicular to each other.

22. The pole according to claim 21, characterized in that The curvature radius R of the outer edge of the first arc portion (a2) and the outer edge of the second arc portion (a4) is 3 mm to 8 mm.

23. The pole according to claim 1, characterized in that The first connection portion (31) has a boss (311) and an annular surface (312) on a side opposite to the first surface (b1); the annular surface (312) is arranged around the boss (311), and the boss (311) is arranged to protrude relative to the annular surface (312) in a direction away from the first surface (b1).

24. The pole according to claim 23, characterized in that A protruding height H1 of the boss (311) relative to the annular surface (312) is 0.05 mm to 0.8 mm.

25. The pole according to claim 1, characterized in that A second groove (315) is provided on the first surface (b1) of the first connecting portion (31), and at least a portion of the second groove (315) gradually narrows or narrows in a step-like manner in a direction from the groove bottom to the groove opening.

26. The pole according to claim 25, characterized in that The depth dimension of the second groove (315) is H2, the thickness dimension of the first connection portion (31) is T9, and H2 and T9 satisfy: H2=(5%-50%)T9.

27. The pole according to claim 10, characterized in that The pole (30) further comprises a transition portion (33), and each of the second connecting portions (32) is connected to the corresponding first connecting portion (31) via the transition portion (33); One end of the transition portion (33) connected to the second connection portion (32) is a first end, and the first end at least partially protrudes from a side of the first connection portion (31) having the first surface (b1) along the thickness direction (Z) of the pole.

28. The pole according to claim 27, characterized in that The flow area of ​​the transition portion (33) is smaller than the flow area of ​​the first connection portion (31), and smaller than the flow area of ​​the second connection portion (32).

29. The pole according to claim 27, characterized in that The thickness dimension of the first connecting portion (31) is T9, the thickness dimension of the transition portion (33) is T13, the thickness dimension of the second region (322) is T11, and T9≥T11>T13.

30. The pole according to claim 29, characterized in that The connecting sub-portion (324) has a first groove (323), and the notch of the first groove (323) passes through one end of the connecting sub-portion (324) away from the second surface (b2); the connecting sub-portion (324) has a bottom wall (3247) and an annular side wall (3245), one end of the annular side wall (3245) is connected to the second area (322), the bottom wall (3247) is connected to the other end of the annular side wall (3245), and the annular side wall (3245) and the bottom wall (3247) together enclose the first groove (323); The thickness dimension of the annular side wall (3245) is T14, the thickness dimension of the bottom wall (3247) is T12, and T9≥T12≥T11>T13>T14.

31. The pole according to claim 27, characterized in that The pole (30) comprises a first metal layer (A) and a second metal layer (B), wherein the first metal layer (A) extends to the first connecting portion (31) and each of the second connecting portions (32); at each of the second connecting portions (32), the second metal layer (B) and the first metal layer (A) are stacked along the thickness direction (Z) of the pole, and a surface of the first metal layer (A) facing away from the second metal layer (B) comprises the fourth surface (b4), and a surface of the second metal layer (B) facing away from the first metal layer (A) is a sixth surface (b6), and the sixth surface (b6) comprises the second surface (b2).

32. The pole according to claim 31, characterized in that The transition portion (33) has a seventh surface (b7), the seventh surface (b7) and the sixth surface (b6) are located on the same side of the pole (30) in the thickness direction (Z), and the seventh surface (b7) and the sixth surface (b6) are transitioned in an arc through an arc segment (332); One end of the second metal layer (B) close to the first connecting portion (31) has a first interface (D), and there is a preset distance L between the first interface (D) and the circular arc segment (332).

33. The pole according to claim 32, characterized in that The preset distance L satisfies: 0.5 mm ≤ L ≤ 6 mm.

34. The pole according to claim 31, characterized in that The connecting sub-portion (324) has a first groove (323), and the notch of the first groove (323) passes through one end of the connecting sub-portion (324) away from the second surface (b2); the connecting sub-portion (324) has a bottom wall (3247) and an annular side wall (3245), one end of the annular side wall (3245) is connected to the second area (322), the bottom wall (3247) is connected to the other end of the annular side wall (3245), and the annular side wall (3245) and the bottom wall (3247) together enclose the first groove (323); The thickness of the second metal layer (B) at the annular side wall (3245) is T7, the thickness of the second metal layer (B) at the second region (322) is T3, and the thickness of the second metal layer (B) at the bottom wall (3247) is T5. T7, T5 and T3 satisfy: T5≥T3>T7.

35. The pole according to claim 34, characterized in that The thickness T5 of the second metal layer (B) at the bottom wall (3247) is 0.3 mm to 1.8 mm; and / or the thickness T5 of the second metal layer (B) at the bottom wall (3247) accounts for 10% to 40% of the thickness of the bottom wall (3247).

36. The pole according to claim 34, characterized in that The thickness T3 of the second metal layer (B) at the second region (322) is 0.05 mm to 1.5 mm; and / or the thickness T3 of the second metal layer (B) at the second region (322) accounts for 10% to 40% of the thickness of the second region (322).

37. The pole according to claim 31, characterized in that At the second region (322), a second interface (E) is formed between the first metal layer (A) and the second metal layer (B); In the thickness direction (Z) of the pole, the second interface (E) protrudes from the first surface (b1) of the first connecting portion (31).

38. The pole according to claim 31, characterized in that The second metal layer (B) extends to each of the transition portions (33) and the first connecting portion (31).

39. The pole according to claim 38, characterized in that The thickness of the second metal layer (B) at the second region (322) is T3, the thickness of the second metal layer (B) at the transition portion (33) is T8, and the thickness of the second metal layer (B) at the first connection portion (31) is T2; T3, T8 and T2 satisfy: T8<T3≤T2.

40. The pole according to claim 39, characterized in that The connecting sub-portion (324) has a first groove (323), and the notch of the first groove (323) passes through one end of the connecting sub-portion (324) away from the second surface (b2); the connecting sub-portion (324) has a bottom wall (3247) and an annular side wall (3245), one end of the annular side wall (3245) is connected to the second area (322), the bottom wall (3247) is connected to the other end of the annular side wall (3245), and the annular side wall (3245) and the bottom wall (3247) together enclose the first groove (323); The thickness dimension of the second metal layer (B) at the bottom wall (3247) is T5, the thickness dimension of the second metal layer (B) at the annular side wall (3245) is T7, and T7<T8<T3≤T5≤T2.

41. The pole according to claim 40, characterized in that T5, T3 and T2 satisfy: T5-T3=0~0.5×T2.

42. The pole according to any one of claims 31 to 41, characterized in that The first metal layer (A) is an aluminum layer, and the second metal layer (B) is a copper layer.

43. A top cover assembly, characterized in that: It comprises a cover plate (10) and a pole (30) according to any one of claims 1 to 42; The cover plate (10) is provided with a first through hole, the first connection portion (31) is arranged on one side of the cover plate (10), a first surface (b1) of the first connection portion (31) faces the cover plate (10), and the second connection portion (32) passes through the first through hole to the other side of the cover plate (10).

44. A battery cell, characterized in that: Comprising a housing, a battery cell assembly and a top cover assembly (100) as claimed in claim 43; At least one end of the shell is open, the battery cell assembly is accommodated in the shell, the top cover assembly covers the opening, and the thickness direction of the shell is consistent with the first preset direction; the battery cell assembly includes at least two groups of battery cells arranged in parallel along the thickness direction of the shell, and at least two groups of battery cells are arranged in a one-to-one correspondence with at least two second connecting parts, and the end face of each group of battery cells extends with a pole ear, and the pole ear of each group of battery cells is respectively connected to the corresponding second connecting part.

45. A battery cell, characterized in that: It comprises a shell, a battery cell assembly and a pole (30) according to any one of claims 1 to 39, wherein the pole is arranged on the shell, and the battery cell assembly is accommodated in the shell.

46. ​​A battery, characterized in that: It comprises a plurality of battery cells as claimed in claim 44 or 45, wherein the plurality of battery cells are electrically connected via an electrical connector, and the electrical connector is connected to the first connecting portion.

47. An electrical device, characterized in that: Includes the battery cell as claimed in claim 44 or 45, or includes the battery as claimed in claim 46.

48. A method for preparing a pole according to any one of claims 1 to 42, characterized in that: The following steps are involved: Providing a plate (101); The plate (101) is pressed and deep drawn; by pressing the plate (101), a first connection area (102) and a plurality of second connection areas (103) are formed on the plate (101); by deep drawing the plate (101), the first connection area (31) is formed in the first connection area (102), and the second connection area (32) is formed in each of the second connection areas (103); The plate (101) is punched out to obtain the pole (30).

49. The method for processing a pole according to claim 48, characterized in that: In the step of providing a plate (101): the thickness of the plate (101) is 2 mm to 8 mm; In the pole (30) obtained by performing the step of punching the plate (101), the thickness dimension T9 of the first connection portion is 2 mm to 8 mm, the thickness dimension T14 of the annular side wall (3245) of each second connection portion (32) is greater than or equal to 0.5 mm, and the thickness dimension T12 of the bottom wall (3247) is greater than or equal to 1.2 mm.

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