Conductive structure, cover plate assembly and battery cell

Abstract

The utility model provides a conductive structure, a cover plate assembly and a battery cell. The conductive structure comprises a first metal column having a first end and a second end which are opposite to each other; the second metal layer is combined on the surface of the first metal column, the second metal layer wraps the first end and extends towards the second end, the second metal layer is used for being connected with a pole lug, the distance between the end portion of the second metal layer and the end face of the second end is H1 in the axial direction of the first metal column, the thickness of the first metal column is D2, and the ratio of H1 to D2 is 0-0.8. According to the conductive structure, the combination area of the second metal layer and the first metal column 1 is increased, the distance between the end part of the second metal layer and the second end of the first metal column is shortened, the current flowing path is further shortened, and the over-current capability of the conductive structure is improved under the combined action of the two.

Description

Technical Field

[0001] The present application relates to the field of battery technology, and in particular to a conductive structure, a cover assembly, and a battery cell. Background Art

[0002] The pole is an important component that connects the inside and outside of the battery cell (also called a battery cell). Usually, one end of the pole is connected to the circuit outside the battery cell, such as the module bar, and the other end of the pole is connected to the internal circuit of the battery cell, such as the pole ear in the electrode assembly through a current collector. At present, most poles are made of a single metal material. For example, the positive pole is made of aluminum and the negative pole is made of copper. However, poles made of a single metal material are prone to welding difficulties. Taking the negative pole as a pure copper pole as an example, when the pure copper pole and the terminal block are laser welded, in order to reduce the cost and weight of the battery cell, the terminal block is generally made of aluminum. Due to the different melting points between copper and aluminum, laser welding can easily fail, resulting in cracking.

[0003] To reduce the difficulty of welding, a composite pole has been designed in related art. This pole consists of two layers of metal made of different materials, stacked one above the other. The different metal layers are joined together by friction welding or stamping. For example, the composite pole is a negative pole, and the composite pole includes an aluminum layer and a copper layer. When a composite pole consists of two layers of different metal materials stacked one above the other, the current path through the composite pole is long, the composite pole has excessive resistance, and the current carrying capacity is poor. Utility Model Content

[0004] The embodiments of the present application provide a conductive structure, a cover plate assembly, and a battery cell, which can improve the technical problem of insufficient current capacity of a composite pole.

[0005] In a first aspect, an embodiment of the present application provides a conductive structure, including:

[0006] a first metal post having opposing first and second ends;

[0007] A second metal layer is bonded to the surface of the first metal column, the second metal layer covers the first end and extends toward the second end, and the second metal layer is used to connect to the tab, wherein along the axial direction of the first metal column, the distance between the end of the second metal layer and the end face of the second end is H1, the thickness of the first metal column is D2, and the ratio of H1 to D2 is 0 to 0.8.

[0008] In one embodiment, the ratio of H1 to D2 is 0.25-0.5.

[0009] In one embodiment, H1 is 0-3.2 mm; and / or D2 is 4-8 mm.

[0010] In one embodiment, the combined area between the second metal layer and the first metal column is greater than or equal to 20 mm 2 .

[0011] In one embodiment, the bonding area is greater than or equal to 80 mm 2 .

[0012] In one embodiment, the average thickness of the second metal layer is less than or equal to 3 mm.

[0013] In one embodiment, the average thickness of the second metal layer is 0.2 mm to 1.5 mm.

[0014] In one embodiment, the volume of the second metal layer is smaller than the volume of the first metal column, and the volume ratio of the second metal layer to the first metal column is 0.1 to 0.65.

[0015] In one embodiment, on the exterior surface of the conductive structure, a ratio of a surface area of ​​the second metal layer to a surface area of ​​the first metal pillar is greater than or equal to 0.25.

[0016] In one embodiment, the diameter of the conductive structure is less than or equal to 10 mm, and the ratio of the surface area of ​​the second metal layer to the surface area of ​​the first metal pillar is greater than or equal to 0.25 and less than or equal to 0.6.

[0017] In one embodiment, the diameter of the conductive structure is greater than 10 mm and less than or equal to 30 mm, and the ratio of the surface area of ​​the second metal layer to the surface area of ​​the first metal column is greater than or equal to 0.75 and less than or equal to 2.

[0018] In one embodiment, the second metal layer includes a first section and a second section, the first section corresponds to an end surface of the first end, and the second section corresponds to a side surface of the first end.

[0019] In one embodiment, the first metal column protrudes radially to form a boss, and the second metal layer extends at least to the boss.

[0020] In one embodiment, the boss is located at the first end, and the second section at least covers a side surface of the boss and a surface of the boss close to the second end.

[0021] In one embodiment, the conductive structure is an integrated pole and a current collecting member, wherein the boss is the current collecting member, and the current collecting member is used to be directly connected to the tab.

[0022] In one embodiment, the boss is away from the first end, and the radial dimension of the boss is larger than the radial dimension of the first end. The second metal layer also includes a third section, and the third section corresponds to a side surface of the boss close to the first end. The second section connects the first section and the third section.

[0023] In one embodiment, the third section is formed as an end portion of the second metal layer, and the third section is embedded in the boss.

[0024] In one embodiment, the boss is located at the second end, the boss is partially exposed outside the second metal layer, the conductive structure is an integrated pole and terminal pressing block, and the boss is the terminal pressing block.

[0025] In one embodiment, the boss is located between the first end and the second end, the radial dimension of the boss is larger than the radial dimension of the second end, and the second metal layer also includes a fourth segment, the fourth segment corresponds to the side of the boss, and the fourth segment is connected to the third segment.

[0026] In one embodiment, the second metal layer further includes a fifth section, the fifth section corresponds to a side surface of the boss away from the first end, and the fourth section connects the fifth section and the third section.

[0027] In one embodiment, the end surface of the first end is partially concave to form a groove, and the first section includes a first sub-segment, a second sub-segment and a third sub-segment connected in sequence, the first sub-segment is located outside the groove, the second sub-segment is located on the side wall of the groove, and the third sub-segment is located on the bottom wall of the groove.

[0028] In one embodiment, the first metal column is an aluminum column, and the second metal layer is a copper layer; and / or, the bonding interface between the second metal layer and the first metal column has an uneven microstructure; and / or, the electrical conductivity of the second metal in the second metal layer is greater than the electrical conductivity of the first metal in the first metal column.

[0029] In a second aspect, an embodiment of the present application provides a cover plate assembly, comprising:

[0030] cover;

[0031] The aforementioned conductive structure is provided on the cover plate.

[0032] In one embodiment, the conductive structure is a pole, and the cover plate assembly further includes a current collecting member, which is located on one side of the cover plate and directly connected to the conductive structure.

[0033] In one embodiment, the conductive structure is an integrated pole and terminal pressing block;

[0034] The cover plate assembly further includes a current collecting member, which is located on one side of the cover plate and directly connected to the conductive structure, and the terminal pressing block presses against the other side of the cover plate.

[0035] In one embodiment, the cover plate comprises:

[0036] Cover body,

[0037] A first insulating member is provided between the conductive structure and the cover body,

[0038] A second insulating member is provided between the cover body and the current collecting member; and / or,

[0039] The cover plate assembly further includes a seal disposed between the cover plate and the conductive structure.

[0040] In a third aspect, an embodiment of the present application provides a battery cell, comprising:

[0041] A housing having a receiving cavity;

[0042] An electrode assembly is disposed in the accommodating cavity, wherein the electrode assembly includes an electrode tab;

[0043] The aforementioned cover plate assembly is connected to the shell and closes the opening of the accommodating cavity, and the conductive structure is connected to the tab.

[0044] Beneficial effects of the embodiments of the present application:

[0045] The conductive structure provided in the embodiment of the present application includes a first metal pillar and a second metal layer. The second metal layer is bonded to the surface of the first metal pillar and is configured to extend from the surface of the first end of the first metal pillar to the second end. This not only effectively increases the bonding area between the second metal layer and the first metal pillar 1, but also shortens the distance between the end of the second metal layer and the second end of the first metal pillar, thereby shortening the current flow path. The two work together to improve the current flow capacity of the conductive structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0047] Figure 11 is a schematic diagram of the main structure of the first conductive structure provided in an embodiment of the present application;

[0048] Figure 2 yes Figure 1 A schematic cross-sectional view of the conductive structure in FIG.

[0049] Figure 3 is a schematic diagram of the main structure of the second conductive structure provided in an embodiment of the present application;

[0050] Figure 4 yes Figure 3 A schematic cross-sectional view of the conductive structure in FIG.

[0051] Figure 5 is a schematic diagram of the three-dimensional structure of the third conductive structure provided in an embodiment of the present application;

[0052] Figure 6 yes Figure 5 A schematic cross-sectional view of the conductive structure in FIG.

[0053] Figure 7 is a schematic cross-sectional view of a fourth conductive structure provided in an embodiment of the present application;

[0054] Figure 8 is a schematic cross-sectional view of a fifth conductive structure provided in an embodiment of the present application;

[0055] Figure 9 is an exploded view of a cover plate assembly provided in an embodiment of the present application;

[0056] Figure 10 is a schematic cross-sectional structural diagram of a battery cell provided in an embodiment of the present application;

[0057] Figure 11 It is a schematic diagram of the cross-sectional structure of the pole provided in Example 1 of the present application.

[0058] The reference numerals are as follows:

[0059] 10. Conductive structure; 101. Pole; 102. Terminal block;

[0060] 1. The first metal pillar;

[0061] 11. first end; 11b. groove;

[0062] 12. Second end;

[0063] 13. Boss;

[0064] 2. Second metal layer;

[0065] 20. End;

[0066] 21, first section; 211, first subsection; 212, second subsection; 213, third subsection;

[0067] 22. Second section;

[0068] 23. The third section;

[0069] 24. Section 4;

[0070] 25. Section 5;

[0071] 100. Cover plate assembly;

[0072] 110, cover plate; 111, cover plate body; 112, first insulating member; 113, second insulating member; 114, mounting hole; 115, injection hole;

[0073] 120, current collecting parts;

[0074] 130. Seals;

[0075] 140. Explosion-proof valve;

[0076] 1000, battery cell;

[0077] 1100, housing; 1110, accommodating chamber;

[0078] 1200. Electrode assembly; 1210. Tab. DETAILED DESCRIPTION

[0079] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0080] Furthermore, it should be understood that the specific embodiments described herein are intended only to illustrate and explain the present application and are not intended to limit the present application. In this application, unless otherwise indicated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the directions of the drawings in the accompanying drawings; whereas "inner" and "outer" refer to the outline of the device.

[0081] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the specified features. In the description of this application, "plurality" means two or more, unless otherwise specifically specified.

[0082] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections, electrical connections, or mutual communication; they can refer to direct connections or indirect connections through an intermediate medium; they can refer to internal communication between two components or the interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0083] The terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0084] In the description of the embodiments of this application, words such as "example" or "for example" are used to indicate an example, illustration, or description. Any embodiment or design described as "for example" or "for example" in the embodiments of this application is not to be construed as being preferred or having more advantages than another embodiment or design. The use of words such as "example" or "for example" is intended to clearly present relative concepts.

[0085] To facilitate understanding of the solution of the present application, the spline curves and arrows used in the drawings are explained here: the components indicated by the spline curves without arrows are solid components, that is, components with solid structures; the components indicated by the spline curves with arrows are virtual components, that is, components without solid structures.

[0086] To address the problem of insufficient current carrying capacity of a composite pole, embodiments of the present application provide a conductive structure, a cover plate assembly, and a battery cell.

[0087] In a first aspect, embodiments of the present application provide a conductive structure for connecting the internal circuit of a battery cell to a circuit external to the battery cell (referred to as the external circuit), thereby enabling communication between the battery cell and the external circuit, enabling the external circuit to power the battery cell (i.e., charging the battery cell), or the battery cell to power the external circuit (i.e., discharging the battery cell). Specifically, the conductive structure can be assembled onto a cover plate of a battery cell.

[0088] Specifically, see Figures 1 to 9Conductive structure 10 includes a first metal pillar 1 and a second metal layer 2, with second metal layer 2 bonded to the surface of first metal pillar 1. First metal pillar 1 has two opposing ends, a first end 11 and a second end 12. Second metal layer 2 covers first end 11 and extends toward second end 12. Second metal layer 2 is used for connection to a tab. Along the axial direction of first metal pillar 1, the distance between end 20 of second metal layer 2 and the end surface of second end 12 is H1. The thickness of first metal pillar 1 is D2, and the ratio of H1 to D2 is 0 to 0.8.

[0089] Conductive structure 10 includes a first metal pillar 1 and a second metal layer 2. It is understood that first metal pillar 1 is a columnar structure made of a first metal; second metal layer 2 is a layered structure made of a second metal. The second metal and the first metal are different metals. Optionally, the conductivity of the second metal is greater than that of the first metal, so that current preferentially flows through the second metal layer 2 before flowing to the first metal pillar 1.

[0090] The second metal layer 2 is bonded to the surface of the first metal pillar 1, meaning that the second metal layer 2 is located on the outer surface of the first metal pillar 1 and is also bonded to the first metal pillar 1. Bonding here means that the second metal layer 2 and the first metal pillar 1 cannot be separated simply under the action of gravity. For example, the second metal layer 2 and the first metal pillar 1 are physically bonded together. As an example, the second metal layer 2 and the first metal pillar 1 can be bonded together by cold heading.

[0091] It can be understood that the second metal layer 2 wraps around the surface of the first end 11, and the second metal layer 2 extends from the surface of the first end 11 to the second end 12. The second metal layer 2 extends from the first end 11 to the second end 12, specifically, the end 20 of the second metal layer 2 extends toward the second end 12. The end 20 of the second metal layer 2 may extend to the second end 12, or the end 20 of the second metal layer 2 may extend to a position between the first end 11 and the second end 12. Optionally, the end 20 of the second metal layer 2 extends to the second end 12, but the second metal layer 2 does not completely wrap around the second end 12. In other words, the second end 12 is at least partially exposed outside the second metal layer 2, so that the second end 12 can be directly connected to other components. Here, the end 20 of the second metal layer 2 refers to the edge portion of the second metal layer 2. In other words, the end surface of the first end 11 of the first metal pillar 1 and at least part of the side surface of the first metal pillar 1 are covered by the second metal layer 2. This can effectively increase the bonding area S between the second metal layer 2 and the first metal pillar 1, thereby improving the current carrying capacity of the conductive structure 10.

[0092] The second metal layer 2 is used to connect to the tab. The second metal layer 2 can be directly connected to the tab, or the second metal layer 2 can be connected to the tab through other intermediate components (such as the current collector 120). As an example, the second metal layer 2 is used to weld to the current collector 120, and the current collector 120 is welded to the tab. Here, the tab refers to the metal conductor that leads the positive and negative electrodes from the battery cell (i.e., the battery cell). As an example, the current collector 120 includes at least one of a collecting disc and a connecting piece.

[0093] When the conductive structure 10 is applied to a battery cell, the first end 11 of the first metal column 1 is directed toward the interior of the battery cell, while the second end 12 is directed toward the outside of the battery cell. The second metal layer 2 wraps the first end 11 of the first metal column 1 and extends from the first end 11 to the second end 12. Thus, the second metal layer 2 can also serve as a protective layer to separate the first end 11 of the first metal column 1 from the electrolyte in the battery cell, thereby reducing the risk of the first end 11 being corroded by the electrolyte.

[0094] It can be foreseen that the end portion 20 of the second metal layer 2 extends toward the second end 12 of the first metal pillar 1, and the distance between the end portion 20 of the second metal layer 2 and the second end 12 of the first metal pillar 1 is shortened. Figure 2 Along the axial direction of the first metal pillar 1, the distance between the end 20 of the second metal layer 2 and the end surface of the second end 12 is H1, and the thickness of the first metal pillar 1 is D2. The ratio of H1 to D2 is 0 to 0.8. It can be understood that the closer the end 20 of the second metal layer 2 is to the second end 12 of the first metal pillar 1, the smaller H1 and the smaller the ratio of H1 to D2. The farther the end 20 of the second metal layer 2 is from the second end 12 of the first metal pillar 1, the larger H1 and the larger the ratio of H1 to D2. When the conductive structure 10 is applied to a battery cell, the first end 11 of the first metal pillar 1 faces the interior of the battery cell, while the second end 12 faces the exterior of the battery cell. Second end 12 can be used to connect to an external circuit. If the distance between the end 20 of the second metal layer 2 and the second end 12 of the first metal pillar 1 is shortened, current can flow quickly through the end 20 of the second metal layer 2 to the second end 12 and the external circuit. This shortens the path of current flowing through the conductive structure 10, improving the current carrying capacity of the conductive structure 10. As an example, the ratio of H1 to D2 is 0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, or 0.8.

[0095] The conductive structure 10 provided in the embodiment of the present application includes a first metal pillar 1 and a second metal layer 2. The second metal layer 2 is bonded to the surface of the first metal pillar 1 and the second metal layer 2 is configured to extend from the surface of the first end 11 of the first metal pillar 1 to the second end 12. This not only effectively increases the bonding area S between the second metal layer 2 and the first metal pillar 1, but also shortens the distance between the end 20 of the second metal layer 2 and the second end 12 of the first metal pillar 1, thereby shortening the current flow path. The two work together to improve the current flow capacity of the conductive structure 10.

[0096] In some embodiments, H1 is 0 to 3.2 mm. When the end 20 of the second metal layer 2 extends to the end surface of the second end 12, H1 is minimum and equal to 0. It can be understood that the smaller H1 is, the smaller the surface area of ​​the first metal pillar 1 exposed outside the second metal layer 2, and the smaller the distance between the end 20 of the second metal layer 2 and the second end 12 of the first metal pillar 1, which is more conducive to improving the current carrying capacity of the conductive structure 10. It should be noted that the extension of the end 20 of the second metal layer 2 to the end surface of the second end 12 does not mean that the end surface of the second end 12 is completely covered by the second metal layer 2. The end surface of the second end 12 can be kept partially exposed to facilitate connection with an external circuit. As an example, H1 is 0, 0.1 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.8 mm, 3.0 mm or 3.2 mm.

[0097] In some embodiments, D2 is 4 mm to 8 mm. Controlling the thickness D2 of the first metal pillar 1 is used to control the volume and cost of the conductive structure 10. As an example, D2 is 4 mm, 5 mm, 6 mm, 7 mm, or 8 mm.

[0098] In some embodiments, the ratio of H1 to D2 is 0.25 to 0.5. Within this range, the conductive structure 10 has a good current carrying capacity and facilitates connection of the second end 12 of the first metal pillar 1 to an external circuit. As examples, the ratio of H1 to D2 is 0.25, 0.3, 0.35, 0.4, 0.45, or 0.5.

[0099] In some embodiments, the bonding area between the second metal layer 2 and the first metal pillar 1 is greater than or equal to 20 mm. 2 The second metal layer 2 is bonded to the surface of the first metal column 1. The surface where the second metal layer 2 and the first metal column 1 contact each other is the bonding surface, also called the contact surface. The bonding area S between the second metal layer 2 and the first metal column 1 refers to the area of ​​the surface where the second metal layer 2 and the first metal column 1 contact each other. Usually, the bonding area S is greater than or equal to 20 mm 2 As an example, the bonding area S is 20 mm 2, 30mm 2 , 40mm 2 , 50mm 2 , 100mm 2 , 150mm 2 , 200mm 2 , 300mm 2 , 400mm 2 or 500mm 2 By controlling the bonding area S between the second metal layer 2 and the first metal column 1 to be greater than or equal to 20 mm 2 , thereby ensuring the current carrying capacity of the conductive structure 10.

[0100] In addition, increasing the bonding area S between the second metal layer 2 and the first metal pillar 1 can also enhance the bonding strength between the second metal layer 2 and the first metal pillar 1 , thereby reducing the risk of the second metal layer 2 falling off.

[0101] In some embodiments, the bonding area S between the second metal layer 2 and the first metal pillar 1 is greater than or equal to 80 mm 2 By increasing the bonding area S, the current carrying capacity of the conductive structure 10 can be further improved and the risk of the second metal layer 2 falling off can be reduced. As an example, the bonding area S is 80 mm 2 , 90mm 2 , 100mm 2 , 120mm 2 , 130mm 2 , 140mm 2 , 150mm 2 , 200mm 2 , 250mm 2 , 300mm 2 , 400mm 2 or 500mm 2 .

[0102] In some embodiments, the average thickness D1 of the second metal layer 2 is less than or equal to 3 mm. By making the second metal layer 2 thinner, the production cost of the conductive structure 10 can be effectively reduced. This is particularly true when the first metal pillar 1 is an aluminum pillar and the second metal layer 2 is a copper layer. This reduces the use of more expensive copper, effectively reducing the cost and weight of the conductive structure 10. By way of example, the average thickness D1 of the second metal layer 2 is 0.4 mm, 0.5 mm, 0.6 mm, 0.8 mm, 1.0 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.5 mm, 2.8 mm, or 3.0 mm.

[0103] In some embodiments, the average thickness D1 of the second metal layer 2 is 0.2 mm to 1.5 mm. Generally, as the average thickness D1 of the second metal layer 2 decreases, the current carrying capacity of the conductive structure 10 decreases, but the cost of the conductive structure 10 is reduced. By designing the average thickness D1 of the second metal layer 2 to be 0.2 mm to 1.5 mm, the conductive structure 10 can have both cost advantages and sufficient current carrying capacity within this range. As an example, the average thickness D1 of the second metal layer 2 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm.

[0104] In some embodiments, the volume of the second metal layer 2 is smaller than the volume of the first metal pillar 1. It is understood that the volume content of the second metal layer 2 in the conductive structure 10 is smaller than the volume content of the first metal pillar 1. By reducing the content of the second metal layer 2 in the conductive structure 10, the cost of the conductive structure 10 can be reduced.

[0105] In some embodiments, the volume ratio of the second metal layer 2 to the first metal pillar 1 is 0.1 to 0.65. That is, the volume of the first metal pillar 1 is 1.54 to 10 times the volume of the second metal layer 2, that is, the volume content of the first metal pillar 1 in the conductive structure 10 is much greater than the volume content of the second metal layer 2. When the bonding area S between the second metal layer 2 and the first metal pillar 1 is increased, the conductive structure 10 still has sufficient current capacity. By reducing the content of the second metal layer 2 in the conductive structure 10, the cost of the conductive structure 10 can be reduced, especially when the first metal pillar 1 is an aluminum pillar and the second metal layer 2 is a copper layer. As an example, the volume ratio of the second metal layer 2 to the first metal pillar 1 is 0.1, 0.2, 0.3, 0.4, 0.5, 0.6 or 0.65. Generally, the volume ratio of the second metal layer 2 to the first metal pillar 1 fluctuates with the size (e.g., diameter) of the conductive structure 10. The larger the size of the conductive structure 10, the smaller the volume ratio of the second metal layer 2 to the first metal pillar 1.

[0106] In some embodiments, see Figure 2On the exterior surface of the conductive structure 10, the ratio A of the surface area of ​​the second metal layer 2 to the surface area of ​​the first metal pillar 1 is greater than or equal to 0.25. Since the second metal layer 2 is bonded to the surface of the first metal pillar 1, the exposed surface of the second metal layer 2 forms the exterior surface of the conductive structure 10; when the first metal pillar 1 is not completely covered by the second metal layer 2, the exposed surface of the first metal pillar 1 also forms the exterior surface of the conductive structure 10. It can be understood that on the exterior surface of the conductive structure 10, the surface area of ​​the second metal layer 2 is the area of ​​the exposed surface of the second metal layer 2, and the surface area of ​​the first metal pillar 1 is the area of ​​the exposed surface of the first metal pillar 1. Increasing the surface area of ​​the second metal layer 2 on the exterior surface of the conductive structure 10 is equivalent to increasing the area of ​​the second metal layer 2 covering the first metal pillar 1, that is, increasing the bonding area S between the second metal layer 2 and the first metal pillar 1, thereby improving the current carrying capacity of the conductive structure 10. As an example, on the exterior surface of the conductive structure 10 , the ratio A of the surface area of ​​the second metal layer 2 to the surface area of ​​the first metal pillar 1 is 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5 or 3.

[0107] In some embodiments, the diameter of the conductive structure 10 is The diameter of the conductive structure 10 is less than or equal to 10 mm, and the ratio A of the surface area of ​​the second metal layer 2 to the surface area of ​​the first metal pillar 1 is greater than or equal to 0.25 and less than or equal to 0.6. In order to facilitate direct connection of the second end 12 with other components, the second end 12 is at least partially exposed outside the second metal layer 2. Generally, the smaller the diameter of the conductive structure 10, the smaller the surface area of ​​the conductive structure 10. In the case of , controlling 0.25≤A≤0.6 can ensure that the second end 12 has enough connection surface to connect with other components, and the bonding area S is large enough, thereby ensuring the current capacity of the conductive structure 10. As an example, is 5mm, 6mm, 7mm, 8mm, 9mm or 10mm, and A is 0.25, 0.3, 0.4, 0.5 or 0.6.

[0108] In some embodiments, the diameter of the conductive structure 10 is The diameter of the conductive structure 10 is greater than 10 mm and less than or equal to 30 mm, and the ratio of the surface area of ​​the second metal layer 2 to the surface area of ​​the first metal column 1 is greater than or equal to 0.75 and less than or equal to 2. As the diameter of the conductive structure 10 increases, the current carrying capacity of the conductive structure 10 is improved, but it also leads to an increase in the cost of the conductive structure 10 and brings a burden on volume and quality. In this case, the conductive structure 10 can have both cost advantages and good current carrying capacity. In addition, the diameter of the conductive structure 10 increases, and the surface area of ​​the conductive structure 10 also increases. A portion of the second end 12 is left exposed outside the second metal layer 2, and the other area can be covered with the second metal layer 2 to increase the bonding area S. In the case of , controlling 0.75≤A≤2 can ensure that the bonding area S is large enough, thereby ensuring the current carrying capacity of the conductive structure 10. As an example, It is 10.1mm, 11mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm or 30mm, and A is 0.75, 0.8, 0.9, 1.0, 1.2, 1.5, 1.7, 1.85 or 2.

[0109] In some embodiments, the first metal is aluminum, i.e., the first metal pillar 1 is an aluminum pillar, and the second metal is copper, i.e., the second metal layer 2 is a copper layer. Aluminum is cheaper than copper, and by configuring the conductive structure 10 as a structure including the aluminum pillar and the copper layer, the cost of the conductive structure 10 can be effectively reduced. For example, the conductive structure 10 is a negative electrode pillar.

[0110] In some embodiments, the bonding interface between the second metal layer 2 and the first metal column 1 has an uneven microstructure. This refers to the uneven fit between the surface of the second metal layer 2 and the surface of the first metal column 1 at the microscopic level. Optionally, the conductive structure 10 is a cold-headed part. As an example, the first metal column 1 is an aluminum column, the second metal layer 2 is a copper layer, and the conductive structure 10 is formed by cold heading of a copper-aluminum composite plate. Since the metal has ductility, during the cold heading process, under pressure, the first metal in the first metal column 1 and the second metal in the second metal layer 2 are deformed and invade each other, so that the bonding interface between the first metal column 1 and the second metal layer 2 is formed into a microscopically uneven wavy surface, which can further increase the bonding area between the first metal column 1 and the second metal layer 2.

[0111] In some embodiments, see Figure 2 、 Figures 6 to 8The second metal layer 2 includes a first section 21 and a second section 22, wherein the first section 21 corresponds to the end surface of the first end 11, and the second section 22 corresponds to the side surface of the first end 11. Here, the first section 21 and the second section 22 refer to two different parts of the second metal layer 2. It can be understood that the end surface of the first end 11 of the first metal pillar 1 is covered by the first section 21, and at least part of the side surface of the first metal pillar 1 is covered by the second section 22. This effectively increases the bonding area S between the second metal layer 2 and the first metal pillar 1, shortens the distance between the end of the second metal layer 2 and the second end 12 of the first metal pillar 1, and thus improves the current carrying capacity of the conductive structure 10. Furthermore, by configuring the second metal layer 2 to include at least two sections, the first section 21 and the second section 22 can wrap around the first end 11, thereby protecting the first end 11 and reducing the risk of electrolyte corrosion. The end 20 of the second metal layer 2 may or may not be located within the second section 22. When the end 20 of the second metal layer 2 is not located in the second section 22, it means that the second metal layer 2 also includes other sections, that is, other parts. Optionally, the number of sections of the second metal layer 2 is less than or equal to five, because more sections increase the manufacturing difficulty and cost.

[0112] In some embodiments, see Figures 1 to 8 , the first metal column 1 protrudes radially to form a boss 13, and the second metal layer 2 extends at least to the boss 13. Specifically, a part of the first metal column 1 protrudes outward roughly along the radial direction of the first metal column 1 to form the boss 13. As an example, the angular deviation between the boss 13 and the radial direction of the first metal column 1 is within ±15°. The second metal layer 2 extends at least to the boss 13, and the end 20 of the second metal layer 2 may extend to the boss 13, or the end 20 of the second metal layer 2 may extend beyond the boss 13, that is, the boss 13 may be completely wrapped in the second metal layer 2, or it may be partially wrapped in the second metal layer 2. When the end 20 of the second metal layer 2 extends to the boss 13, the end 20 of the second metal layer 2 may be embedded in the boss 13, or it may be located only on the surface of the boss 13. By making the first metal column 1 radially protrude to form a boss 13, the boss 13 can be used to increase the outer surface area of ​​the first metal column 1, and the second metal layer 2 also partially or even completely covers the boss 13, thereby increasing the bonding area between the second metal layer 2 and the first metal column 1, and improving the current carrying capacity of the conductive structure 10.

[0113] In addition, when the conductive structure 10 is applied to a battery cell, the boss 13 can serve as a stopping structure to cooperate with other components (such as the cover plate 110). At the same time, since the second metal layer 2 extends at least to the boss 13, the second metal layer 2 will be clamped between the boss 13 and the component that cooperates with the boss 13, thereby preventing the risk of the second metal layer 2 detaching from the first metal column 1.

[0114] In some embodiments, see Figure 3 and Figure 4 , the boss 13 is located at the first end 11, and the second section 22 covers at least the side surface of the boss 13 and the side surface of the boss 13 close to the second end 12, that is, the boss 13 is completely covered in the second metal layer 2. As an example, see Figure 3 The conductive structure 10 is generally shaped like an inverted T. When assembling the conductive structure 10 onto the cover 110, the smaller end of the conductive structure 10 can be passed through the mounting hole 114 on the cover 110 from bottom to top until the boss 13 abuts the cover 110. The second metal layer 2 on the upper surface of the boss 13 is clamped between the boss 13 and the cover 110 to prevent the second metal layer 2 from falling off.

[0115] In some embodiments, see Figure 3 and Figure 4 , the conductive structure 10 is an integrated pole-current collector structure, that is, the conductive structure 10 is an integrated pole 101 and a current collector 120, wherein the boss 13 is the current collector 120, and the current collector 120 is used to directly connect to the pole lug. By integrating the pole 101 and the current collector 120, the process of assembling the pole 101 and the current collector 120 can be omitted, thereby reducing the production cost of the battery cell. In addition, since the second metal layer 2 extends onto the boss 13, that is, the second metal layer 2 extends onto the current collector 120, there is no need to increase the volume of the pole 101. Only by reusing the current collector 120 can the bonding area of ​​the second metal layer 2 be greatly increased, thereby improving the current carrying capacity of the conductive structure 10, reducing the risk of the second metal layer 2 falling off, and without bringing about the burden of volume and weight. The above-mentioned current collector 120 is also a component in the battery cell, and the current collector 120 is usually located inside the battery cell. That is, when the terminal-current collector integrated structure is assembled on a battery cell, such as the cover plate 110 of the battery cell, the boss 13 is located inside the battery cell. The current collector 120 is also used to electrically connect to the tabs of the electrode assembly.

[0116] In some embodiments, see Figures 1 to 2 、 Figures 5 to 8 , the boss 13 is away from the first end 11, and the radial dimension of the boss 13 is larger than the radial dimension of the first end 11. The boss 13 can be located at the second end 12, or between the first end 11 and the second end 12. As an example, see Figure 1When the boss 13 is located at the second end 12, the conductive structure 10 has a generally upright T-shape. When assembling the conductive structure 10 onto the cover 110, the smaller end of the conductive structure 10 can be passed through the mounting hole in the cover 110 from top to bottom until the boss 13 abuts the cover 110. The second metal layer 2 on the lower surface of the boss 13 is clamped between the boss 13 and the cover 110 to prevent the second metal layer 2 from falling off.

[0117] Alternatively, see Figure 2 、 Figures 6 to 8 The second metal layer 2 further includes a third section 23, which corresponds to a side surface of the boss 13 near the first end 11. The second section 22 connects the first section 21 and the third section 23. The third section 23 refers to the portion of the second metal layer 2 that is different from the second section 22 of the first section 21. The end 20 of the second metal layer 2 may or may not be located in the third section 23. When the end 20 of the second metal layer 2 is not located in the third section 23, it means that the second metal layer 2 also includes other sections, i.e., other parts.

[0118] By setting the second metal layer 2 to also include a third section 23, and the third section 23 extending to the surface of the boss 13, the bonding area between the second metal layer 2 and the first metal column 1 can be further increased, the current carrying capacity of the conductive structure 10 can be improved, and the risk of the second metal layer 2 falling off can be reduced.

[0119] In some embodiments, see Figure 2 , the third section 23 forms the end 20 of the second metal layer 2, and the third section 23 is embedded in the boss 13. By configuring the second metal layer 2 to include only three sections, the manufacturing difficulty of the conductive structure 10 can be reduced. At the same time, the third section 23, which serves as the end 20 of the second metal layer 2, is also embedded in the boss 13, increasing the bonding area between the second metal layer 2 and the first metal pillar 1, improving the current carrying capacity of the conductive structure 10 and the bonding strength between the second metal layer 2 and the first metal pillar 1, thereby making the conductive structure 10 more cost-effective.

[0120] In some embodiments, see Figures 1 to 2 、 Figures 5 and 6 The boss 13 is located at the second end 12, and the boss 13 is partially exposed outside the second metal layer 2. The boss 13 is located at the second end 12. When the conductive structure 10 and the cover plate 110 are assembled, the boss 13 is generally located outside the cover plate 110. By arranging the boss 13 to be partially exposed outside the second metal layer 2, it is convenient for the boss 13 to be directly connected to other components (such as the module bar).

[0121] Alternatively, see Figure 2, the conductive structure 10 is an integrated structure of a pole and a terminal block, that is, the conductive structure 10 is an integrated pole 101 and a terminal block 102, wherein the boss 13 is the terminal block 102. By integrating the pole 101 and the terminal block 102, the process of assembling the pole 101 and the terminal block 102 can be omitted, thereby reducing the production cost of the battery cell. In addition, since the second metal layer 2 extends onto the boss 13, that is, the second metal layer 2 extends onto the terminal block 102, there is no need to increase the volume of the pole 101. By simply reusing the terminal block 102, the bonding area of ​​the second metal layer 2 can be greatly increased, thereby improving the current carrying capacity of the conductive structure 10 and reducing the risk of the second metal layer 2 falling off, without bringing about the burden of volume and weight. When the pole and terminal block integrated structure is assembled on a battery cell, such as on the cover plate 110 of the battery cell, the boss 13 as the terminal block 102 is located on the outside of the battery cell, for example, pressed against the cover plate 110, so that fixation can be achieved.

[0122] In some embodiments, see Figures 7 and 8 , the boss 13 is located between the first end 11 and the second end 12, and the radial dimension of the boss 13 is larger than the radial dimension of the second end 12. As an example, see Figure 7 and Figure 8 When the boss 13 is located between the first end 11 and the second end 12, the radial dimension (e.g., diameter) of the boss 13 is larger than the radial dimension of the first end 11 and also larger than the radial dimension of the second end 12, and the conductive structure 10 is roughly shaped like a "Z" character. For this type of conductive structure 10, when the boss 13 serves as a stopper, the boss 13 can be clamped from both sides to achieve a more stable fixation of the second metal layer 2. To prevent the conductive structure 10 from being too high, the boss 13 is optionally made thin, and the second end 12 is used for electrical connection with other components.

[0123] Alternatively, see Figure 7 The second metal layer 2 further includes a fourth section 24, which corresponds to the side surface of the boss 13 and is connected to the third section 23. The provision of the fourth section 24 can further increase the bonding area between the second metal layer 2 and the first metal pillar 1. Here, the side surface of the boss 13 can be completely covered by the fourth section 24, or can be partially covered by the fourth section 24.

[0124] Alternatively, see Figure 8 The second metal layer 2 further includes a fifth section 25, which corresponds to a surface of the boss 13 that is distal from the first end 11. The fourth section 24 connects the fifth section 25 and the third section 23. The provision of the fifth section 25 can further increase the bonding area between the second metal layer 2 and the first metal pillar 1. Optionally, the end 20 of the second metal layer 2 is located in the fifth section 25.

[0125] In some embodiments, see Figures 6 to 8 The end surface of the first end 11 is partially concave to form a groove 11b. The first section 21 includes a first sub-segment 211, a second sub-segment 212 and a third sub-segment 213 connected in sequence. The first sub-segment 211 is located outside the groove 11b, the second sub-segment 212 is located on the side wall of the groove 11b, and the third sub-segment 213 is located on the bottom wall of the groove 11b. The concave here means being concave toward the inside of the first metal column 1. The end surface of the first end 11 forms a groove 11b, and the second metal layer 2 also adapts to the surface of the first end 11 to form a second sub-segment 212 and a third sub-segment 213 that fit the inner wall surface of the groove 11b. By providing a groove 11b on the end surface of the first end 11 and the second metal layer 2 being attached to the inner wall surface of the groove 11b, the bonding area between the second metal layer 2 and the first metal column 1 is increased, thereby improving the current carrying capacity of the conductive structure 10.

[0126] In a second aspect, an embodiment of the present application further provides a cover plate assembly, which is used to cooperate with the shell of the battery cell to form a closed cavity, and the cavity is used to accommodate the electrode assembly of the battery cell.

[0127] Specifically, see Figure 9 The cover plate assembly 100 includes a cover plate 110 and the aforementioned conductive structure 10 , and the conductive structure 10 is connected to the cover plate 110 . Specifically, the conductive structure 10 is disposed on the cover plate 110 .

[0128] In detail, along the thickness direction of the cover plate 110, the cover plate 110 has a first surface and a second surface that are opposite to each other. Figure 9 When the cover plate assembly 100 is mounted on the housing 1100 of the battery cell 1000, the first surface is the side surface away from the housing 1100, and the second surface is the side surface close to the housing 1100. A mounting hole 114 is provided through the cover plate 110 along its thickness, and the conductive structure 10 is mounted on the cover plate 110 through the mounting hole 114.

[0129] In some embodiments, see Figure 9, the conductive structure 10 is an integrated pole 101 and a terminal pressing block 102; the cover plate assembly 100 also includes a current collector 120. The current collector 120 is a conductive component in the battery cell 1000 for connecting to the pole tab 1210 of the electrode assembly 1200. The current collector 120 is located on one side of the cover plate 110, specifically on the side of the cover plate 110 away from the terminal pressing block 102, that is, the current collector 120 is located on the second surface of the cover plate 110, and the terminal pressing block 102 presses against the other side of the cover plate 110, that is, the first surface of the cover plate 110. The current collector 120 is directly connected to the conductive structure 10, for example, by welding. Specifically, the current collector 120 is welded to the second metal layer 2 in the conductive structure 10. Optionally, the material of the current collector 120 is the same as that of the second metal layer 2, that is, the material of the current collector 120 is the second metal, which can reduce the difficulty of welding the current collector 120 to the second metal layer 2 and improve the reliability of welding.

[0130] In some embodiments, see Figure 9 The conductive structure 10 is a pole 101, and the cover plate assembly 100 further includes a current collector 120. The current collector 120 is located on one side of the cover plate 110, for example, the current collector 120 is located on the second surface of the cover plate 110. The current collector 120 is directly connected to the conductive structure 10, for example, by welding.

[0131] In some embodiments, the current collecting member 120 includes at least one of a current collecting plate and a connecting piece.

[0132] In some embodiments, the current collector 120 includes a current collector body (not shown) and a connecting piece (not shown), the current collector body is connected to the connecting piece, wherein the current collector body is used to connect to the electrode tab 1210 of the electrode assembly, and the connecting piece is welded to the second metal layer.

[0133] In some embodiments, see Figure 9 The cover plate 110 includes a cover plate body 111, a first insulating member 112 and a second insulating member 113, wherein the first insulating member 112 and the second insulating member 113 are respectively arranged on opposite sides of the cover plate body 111. The first insulating member 112 is arranged between the conductive structure 10 and the cover plate body 111, and the second insulating member 113 is arranged between the cover plate body 111 and the current collecting member 120. Optionally, in the case where the first metal column 1 in the conductive structure 10 has a boss 13, the first insulating member 112 is arranged between the boss 13 and the cover plate body 111. A mounting hole 114 is provided on the cover plate 110, and the mounting hole 114 passes through the cover plate body 111, the first insulating member 112 and the second insulating member 113. As an example, the cover plate body 111 is a plain aluminum sheet, and the first insulating member 112 and the second insulating member 113 are both plastic parts.

[0134] In some embodiments, see Figure 9The cover assembly 100 further includes a seal 130 disposed between the cover 110 and the conductive structure 10 to seal the gap between the conductive structure 10 and the mounting hole to prevent electrolyte leakage. For example, the seal 130 is located between the cover body 111 and the second insulating member 113.

[0135] In some embodiments, the assembly process of the cover assembly 100 includes: stacking the second insulating member 113, the sealing member 130, the cover body 111 and the first insulating member 112 in sequence from bottom to top with the holes aligned, passing the conductive structure 10 through the mounting hole 114 from top to bottom, abutting the larger end of the conductive structure 10 (for example, the boss 13) on the first insulating member 112, installing the current collecting member 120 on the side of the second insulating member 113 away from the sealing member 130, and welding the current collecting member 120 to the conductive structure 10, for example, the second metal layer 2 in the conductive structure 10, by laser welding.

[0136] In some embodiments, see Figure 9 The cover plate assembly 100 further includes an explosion-proof valve 140 , which is disposed on the cover plate 110 .

[0137] In some embodiments, see Figure 9 The cover plate 110 is further provided with a liquid injection hole 115 and a sealing structure (not shown) for sealing the liquid injection hole.

[0138] Thirdly, see Figure 10 The embodiment of the present application further provides a battery cell 1000 , which is also called a battery cell. The battery cell 1000 refers to a basic unit for realizing the mutual conversion between chemical energy and electrical energy.

[0139] Specifically, the battery cell 1000 includes a housing 1100, an electrode assembly 1200, and the aforementioned cap assembly 100. Specifically, the housing 1100 has a receiving cavity 1110, in which the electrode assembly 1200 is disposed. The cap assembly 100 is connected to the housing 1100 and seals the opening of the receiving cavity 1110. The electrode assembly 1200 includes a tab 1210, to which the conductive structure 10 is connected.

[0140] Specifically, the electrode assembly 1200 further includes an electrode sheet and a separator, and the tab 1210 is connected to the electrode sheet. The electrode sheet includes a positive electrode sheet and a negative electrode sheet, and the separator is located between the positive electrode sheet and the negative electrode sheet. It can be understood that the tab 1210 also includes a positive electrode tab and a negative electrode tab, wherein the positive electrode tab is connected to the positive electrode sheet, and the negative electrode tab is connected to the negative electrode sheet.

[0141] In addition, the battery cell 1000 further includes an electrolyte, which is located in the receiving cavity 1110 , and the electrode assembly 1200 is immersed in the electrolyte.

[0142] The following describes it in detail with reference to specific embodiments.

[0143] Example 1

[0144] Provided is a pole, the preparation process of the pole is as follows:

[0145] S1. Use a punching machine to punch out the copper-aluminum composite plate (the copper layer thickness accounts for 21% of the overall material thickness) into columnar blanks (with a diameter of 12.8 mm) according to the required size;

[0146] S2. Place the blank in a shaping jig for shaping to improve the consistency of the blank size and remove a small amount of copper material attached to the top surface of the aluminum layer;

[0147] S3, placing the columnar blanks in a screening tray, screening out the blanks that meet the requirements (i.e., the copper and aluminum surfaces face the same direction), and loading them into the first cold heading die;

[0148] S4, the blank is placed in a first cold heading die for cold heading processing, so that the aluminum layer material is squeezed toward the copper layer material to obtain a mushroom head shaped semi-finished product;

[0149] S5. The mushroom-shaped semi-finished product is fed into a second cold heading die through a clamping jaw for further cold heading, and the copper layer is spread to the surrounding areas by squeezing the top aluminum layer;

[0150] S6. Remove excess material from the semi-finished product to obtain a finished product, i.e., a pole.

[0151] Figure 11 The figure shows the cross-sectional structure of the pole prepared in Example 1, wherein the first metal pole 1 is an aluminum pole and the second metal layer 2 is a copper layer. The resistance value of different areas of the pole is tested. The specific test process is as follows: 10 poles are randomly selected from all the finished products prepared in Example 1 as samples for testing; please continue to refer to Figure 11 , where test scheme one uses a multimeter to test the resistance value between point a (located at the top of the copper layer) and point b (the center of the end face of the aluminum column); test scheme two uses a multimeter to test the resistance value between point a and point c (the edge of the end face of the aluminum column); the results obtained from the two test schemes are recorded in Table 1.

[0152] Table 1

[0153] Test plan 1 Test Plan 2 Sample 1 0.016mΩ 0.011mΩ Sample 2 0.013mΩ 0.011mΩ Sample 3 0.015mΩ 0.013mΩ Sample 4 0.014mΩ 0.012mΩ Sample 5 0.011mΩ 0.010mΩ Sample 6 0.013mΩ 0.011mΩ Sample 7 0.014mΩ 0.010mΩ Sample 8 0.012mΩ 0.009mΩ Sample 9 0.011mΩ 0.008mΩ Sample 10 0.014mΩ 0.011mΩ

[0154] As shown in Table 1, averaging the resistance test results of the 10 samples yields an average resistance of 0.0133 mΩ for points a-b, and 0.0106 mΩ for points a-c. In the pole, the copper layer wraps around one side of the aluminum post. Because copper has better electrical conductivity than aluminum, current preferentially flows through the copper layer. The end of the copper layer is embedded in the aluminum post, and the distance from the copper layer to point b is greater than the distance from the copper layer to point c. Therefore, the average resistance of points a-b is greater than the average resistance of points a-c. This indicates that extending the end of the copper layer to the side of the aluminum post (specifically, the bottom surface of the boss) can shorten at least part of the current flow path, improving the pole's overcurrent capacity.

[0155] The above is a detailed introduction to the embodiments of the present application. Specific examples are used herein to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method and core idea of ​​the present application. At the same time, for those skilled in the art, based on the ideas of the present application, there may be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A conductive structure, characterized in that: include: a first metal post having opposing first and second ends; A second metal layer is bonded to the surface of the first metal column, the second metal layer covers the first end and extends toward the second end, and the second metal layer is used to connect to the tab, wherein along the axial direction of the first metal column, the distance between the end of the second metal layer and the end face of the second end is H1, the thickness of the first metal column is D2, and the ratio of H1 to D2 is 0 to 0.

8.

2. The conductive structure according to claim 1, wherein: The ratio of H1 to D2 is 0.25 to 0.

5.

3. The conductive structure according to claim 1, wherein: The H1 is 0 to 3.2 mm; and / or the D2 is 4 to 8 mm.

4. The conductive structure according to claim 1, wherein: The combined area between the second metal layer and the first metal column is greater than or equal to 20 mm 2 .

5. The conductive structure according to claim 4, characterized in that: The bonding area is greater than or equal to 80 mm 2 . The conductive structure according to claim 1 , wherein: The average thickness of the second metal layer is less than or equal to 3 mm.

7. The conductive structure according to claim 6, characterized in that: The average thickness of the second metal layer is 0.2 mm to 1.5 mm.

8. The conductive structure according to claim 1, wherein: The volume of the second metal layer is smaller than that of the first metal column, and a volume ratio of the second metal layer to the first metal column is 0.1 to 0.

65.

9. The conductive structure according to claim 1, wherein: On the exterior surface of the conductive structure, a ratio of a surface area of ​​the second metal layer to a surface area of ​​the first metal column is greater than or equal to 0.

25.

10. The conductive structure according to claim 9, characterized in that: The diameter of the conductive structure is less than or equal to 10 mm, and the ratio of the surface area of ​​the second metal layer to the surface area of ​​the first metal pillar is greater than or equal to 0.25 and less than or equal to 0.6; Alternatively, the diameter of the conductive structure is greater than 10 mm and less than or equal to 30 mm, and the ratio of the surface area of ​​the second metal layer to the surface area of ​​the first metal column is greater than or equal to 0.75 and less than or equal to 2.

11. The conductive structure according to any one of claims 1 to 10, characterized in that: The second metal layer includes a first section and a second section, the first section corresponds to an end surface of the first end, and the second section corresponds to a side surface of the first end.

12. The conductive structure according to claim 11, wherein: The first metal column protrudes radially to form a boss, and the second metal layer at least extends to the boss.

13. The conductive structure according to claim 12, wherein: The boss is located at the first end, and the second section at least covers a side surface of the boss and a side surface of the boss close to the second end.

14. The conductive structure according to claim 13, wherein: The conductive structure is an integrated pole and a current collecting member, wherein the boss is the current collecting member, and the current collecting member is used to be directly connected to the tab.

15. The conductive structure according to claim 12, wherein: The boss is away from the first end, and the radial dimension of the boss is larger than the radial dimension of the first end. The second metal layer also includes a third section, which corresponds to a side surface of the boss close to the first end. The second section connects the first section and the third section.

16. The conductive structure according to claim 15, characterized in that: The third section is formed as an end portion of the second metal layer, and the third section is embedded in the boss.

17. The conductive structure according to claim 15, characterized in that: The boss is located at the second end, and a portion of the boss is exposed outside the second metal layer. The conductive structure is an integrated pole and a terminal pressing block, wherein the boss is the terminal pressing block.

18. The conductive structure according to claim 15, wherein: The boss is located between the first end and the second end, and the radial dimension of the boss is larger than the radial dimension of the second end. The second metal layer also includes a fourth section, which corresponds to the side of the boss and is connected to the third section.

19. The conductive structure according to claim 18, wherein: The second metal layer further includes a fifth section corresponding to a side surface of the boss away from the first end, and the fourth section connects the fifth section and the third section.

20. The conductive structure according to claim 11, wherein: The end surface of the first end is partially concave to form a groove, and the first section includes a first sub-segment, a second sub-segment and a third sub-segment connected in sequence, the first sub-segment is located outside the groove, the second sub-segment is located on the side wall of the groove, and the third sub-segment is located on the bottom wall of the groove.

21. The conductive structure according to any one of claims 1 to 10, characterized in that: The first metal column is an aluminum column, and the second metal layer is a copper layer; and / or the bonding interface between the second metal layer and the first metal column has an uneven microstructure; and / or the electrical conductivity of the second metal in the second metal layer is greater than the electrical conductivity of the first metal in the first metal column.

22. A cover plate assembly, characterized in that: include: cover; The conductive structure according to any one of claims 1 to 21, wherein the conductive structure is provided through the cover plate.

23. The cover plate assembly according to claim 22, wherein: The conductive structure is a pole, and the cover plate assembly further includes a current collecting member, which is located on one side of the cover plate and directly connected to the conductive structure; or; the conductive structure is an integrated pole and a terminal block, and the cover plate assembly further includes a current collecting member, which is located on one side of the cover plate and directly connected to the conductive structure, and the terminal block presses against the other side of the cover plate.

24. The cover plate assembly according to claim 23, wherein: The cover plate comprises: Cover body, A first insulating member is provided between the conductive structure and the cover body, A second insulating member is provided between the cover body and the current collecting member; and / or, The cover plate assembly further includes a seal disposed between the cover plate and the conductive structure.

25. A battery cell, characterized in that: include: A housing having a receiving cavity; An electrode assembly is disposed in the accommodating cavity, wherein the electrode assembly includes an electrode tab; The cover plate assembly according to any one of claims 22 to 24, wherein the cover plate assembly is connected to the shell and closes the opening of the accommodating cavity, and the conductive structure is connected to the tab.

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