Pole, cover plate assembly and battery monomer

Abstract

The utility model provides a pole, a cover plate assembly and a battery monomer, and relates to the technical field of batteries. The pole comprises a first metal piece and a second metal piece; the first metal piece is provided with a first concave part, and a first convex part is arranged on the inner wall of the first concave part; the second metal piece comprises a main body and a second convex part which are connected with each other, a second concave part is arranged on the peripheral surface of the second convex part, the second convex part is embedded in the first concave part, and the first convex part is embedded in the second concave part; the side, away from the bottom wall of the first concave part, of the second concave part is a first surface, and a gap is only formed between the first convex part and the first surface. According to the scheme, the second metal piece with better material fluidity extrudes the first metal piece, so that a larger extrusion surface where the second metal piece extrudes the first metal piece is formed. Therefore, the extrusion force between the two metal materials can be ensured based on the better flowability of the second metal piece, so that the gap of the bonding surface between the second metal piece and the first metal piece can be reduced, and the overcurrent capacity of the pole is improved.

Description

Technical Field

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

[0002] The electrode is a key component that connects the inside and outside of a battery cell. One end of the electrode is connected to the external circuit of the battery cell, and the other end is connected to the internal cell of the power battery. To reduce cost and weight, the external circuit of the battery cell uses aluminum for current transmission. However, within the battery cell, the negative electrode current collector and the current collector of the negative electrode sheet are made of the same material: copper. Therefore, to improve the conductivity of the electrode and control the weight and cost of the battery cell, a copper-aluminum composite electrode is used to connect the negative electrode current collector to the external circuit. The copper material of the copper-aluminum composite electrode is connected to the negative electrode current collector, and the aluminum material of the copper-aluminum composite electrode is connected to the external circuit.

[0003] In related art, an interlocking structure is provided between the copper and aluminum materials to ensure a reliable bond. However, since the interlocking structure is formed by press-forming, the area of ​​the contact surface between the copper and aluminum materials is small, thereby reducing the current carrying capacity of the terminal. Utility Model Content

[0004] The embodiments of the present application provide a pole, a cover plate assembly, and a battery cell, which can improve the current-carrying capacity of the pole.

[0005] In the first aspect, an embodiment of the present application provides a pole, which includes a first metal part and a second metal part; the first metal part has a first recess, and a first protrusion is protruding from the inner wall of the first recess on one side close to its opening; the second metal part includes a main body and a second protrusion connected to each other, and a second recess is provided on the outer peripheral surface of the second protrusion, the second protrusion is embedded in the first recess, and the first protrusion is embedded in the second recess; the side of the second recess away from the bottom wall of the first recess is a first surface; wherein, there is a gap between the first metal part and the second metal part only between the first protrusion and the first surface; the material fluidity of the second metal part is greater than the material fluidity of the first metal part.

[0006] In one embodiment, the first surface includes a top surface and a transition surface, one side of the transition surface is connected to a side of the top surface close to the axis of the pole, and the other side smoothly transitions to the bottom wall of the second recess.

[0007] In one embodiment, the spacing of the gap is W1, which satisfies: W1≤0.1 mm.

[0008] In one embodiment, along the radial direction of the pole, an end of the second protrusion away from the main body has a first radius R1, and the main body has a second radius R2, satisfying: R1>R2.

[0009] In one embodiment, the difference between the first radius R1 and the second radius R2 is ΔR, which satisfies the following: 40% R2≤ΔR≤60% R2.

[0010] In one embodiment, the second concave portion extends around the axis of the pole to form an annular structure, and the first convex portion extends around the axis of the pole to form an annular structure.

[0011] In one embodiment, it includes a radial extension portion and an axial extension portion, the radial extension portion is radially inwardly arranged from the inner wall of the first recess near its opening, the radial extension portion has a top end surface facing away from the bottom wall of the first recess, and the axial extension portion extends from the top end surface in a direction away from the bottom wall of the first recess.

[0012] In one embodiment, the radius of the outer peripheral surface of the axially extending portion is consistent with the radius of the main body portion.

[0013] In one embodiment, the outer circumferential surface of the first protrusion is cocircumferentially arranged with the outer circumferential surface of the main body.

[0014] In one embodiment, the first metal component is made of copper, and the second metal component is made of aluminum.

[0015] In the second aspect, an embodiment of the present application provides a cover plate assembly, which includes a cover plate, an upper plastic part, a lower plastic part, a current collecting part, a sealing ring and the aforementioned pole; the pole is passed through the cover plate, and the terminal is located on one side of the cover plate; the upper plastic part is arranged between the terminal and the cover plate; the lower plastic part is arranged on the other side of the cover plate; one end of the current collecting part is connected to the end of the pole away from the terminal; and the sealing ring is arranged between the pole and the mounting hole.

[0016] In a third aspect, an embodiment of the present application provides a battery cell, which includes a shell, an electrode assembly and the aforementioned cover assembly; the shell has a accommodating cavity; the electrode assembly is arranged in the accommodating cavity; the cover is connected to the shell and closes the opening of the accommodating cavity, and the other end of the current collector is connected to the electrode assembly.

[0017] Beneficial effects of the embodiments of the present application:

[0018] In the embodiments of the present application, by arranging the first protrusion to fit within the second recess and the second protrusion to fit within the first recess, a structure is formed in which the first and second metal parts fit together, thereby ensuring the reliability of the bonding between the two metal materials. Furthermore, by fitting one end of the second metal part, which has a higher material fluidity, into the first metal part, the second metal part, which has a higher material fluidity, can be used to press the first metal part during the extrusion forming of the pole, thereby forming a larger extrusion surface of the second metal part pressing the first metal part. In this way, the extrusion force between the two metal materials can be ensured based on the higher material fluidity of the second metal part, thereby reducing the gap at the bonding surface between the second metal part and the first metal part, thereby improving the current carrying capacity of the pole. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] Figure 1 is a schematic structural diagram of a pole provided in an embodiment of the present application;

[0021] Figure 2 is a top view of a pole provided in an embodiment of the present application;

[0022] Figure 3 It is along Figure 2 Cross-sectional view of AA;

[0023] Figure 4 yes Figure 3 Enlarged view of point C in the middle;

[0024] Figure 5 It is along Figure 3 Cross-sectional view of the middle BB;

[0025] Figure 6 is a schematic structural diagram of a first metal member provided in an embodiment of the present application;

[0026] Figure 7 It is a structural schematic diagram of the cover assembly provided in an embodiment of the present application.

[0027] Description of reference numerals:

[0028] 011-pole;

[0029] 111 - first metal member; 1112 - first recess; 1113 - first protrusion; 1114 - radial extension; 1115 - axial extension; 1116 - top end surface;

[0030] 112 - second metal member; 1121 - main body; 1122 - second convex portion; 1123 - second concave portion; 1124 - first surface; 1125 - top surface; 1126 - transition surface;

[0031] 012-terminal;

[0032] 002-cover assembly; 021-cover; 022-upper plastic part; 023-lower plastic part; 024-current collecting part. DETAILED DESCRIPTION

[0033] With reference to the drawings and the embodiments of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described. Obviously, the described embodiments are only part of the embodiments of the present application, but not all of them. Based on the embodiments of the present application, any other embodiments obtained by a person of ordinary skill in the art without creative effort are within the scope of the present application.

[0034] In addition, it should be understood that the specific implementation described herein is only used to illustrate and explain the present application, and is not used to limit the present application. In the present application, the terms "first", "second" are only used for description purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features. Therefore, the features with "first" and "second" can explicitly or implicitly include one or more of the features.

[0035] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection or can communicate with each other; it can be directly connected, or indirectly connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0036] The term "including", "containing" or any other variant thereof is intended to cover non-exclusive inclusion, so that the product including a series of elements not only includes those elements, but also includes other elements not explicitly listed.

[0037] In the description of the embodiments of the present application, the words "example" or "for example" are used to represent examples, illustrations or descriptions. Any embodiment or design scheme described as "example" or "for example" in the embodiments of the present application is not interpreted as more preferred or having more advantages than another embodiment or design scheme. The use of "example" or "for example" and the like is intended to present the relative concept in a clear manner.

[0038] Before introducing the pole, cover plate assembly and battery cell provided by the present application, first introduce the related background information of the embodiments of the present application.

[0039] In related art, to ensure the reliability of the connection between the copper and aluminum materials of the pole, multiple interlocking structures are formed by respectively arranging copper extrusion aluminum and aluminum extrusion copper at multiple joints between the copper and aluminum materials. Since copper has better conductivity than aluminum, the end of the aluminum is wrapped with copper, and the end of the aluminum is concave by extruding copper into the end of the aluminum, so as to form a structure in which the copper is embedded in the aluminum at one end of the pole. As a result, the copper extrusion aluminum structure accounts for a large proportion.

[0040] However, copper has poor material fluidity. When copper is used to extrude aluminum, the extrusion force of the copper on the aluminum will be insufficient, resulting in a large gap between the copper and aluminum in the interlocking structure formed by the copper extrusion of aluminum, which reduces the current capacity of the pole.

[0041] Based on this, in order to ensure the reliability of the bonding between copper and aluminum materials while improving the current carrying capacity therebetween, the embodiments of the present application provide a pole, a cover plate assembly and a battery cell, which are described in detail below.

[0042] See also Figures 1-4 , Figure 1 is a schematic structural diagram of the pole 011 provided in an embodiment of the present application. Figure 2 is a top view of the pole 011 provided in an embodiment of the present application, Figure 3 It is along Figure 2 The cross-sectional view of AA in the figure, Figure 4 yes Figure 3 In the enlarged view at point C in the middle, an embodiment of the present application provides a pole 011. The pole 011 includes a first metal part 111 and a second metal part 112. The first metal part 111 has a first recess 1112. A first protrusion 1113 is provided on the inner wall of the first recess 1112, near its opening. The second metal part 112 includes a main body 1121 and a second protrusion 1122 connected to each other. A second recess 1123 is provided on the outer peripheral surface of the second protrusion 1122. The second protrusion 1122 is embedded in the first recess 1112. The first protrusion 1113 is embedded in the second recess 1123. The side of the second recess 1123 away from the bottom wall of the first recess 1112 is a first surface 1124. There is a gap between the first metal part 111 and the second metal part 112 only between the first protrusion 1113 and the first surface 1124; the material fluidity of the second metal part 112 is greater than the material fluidity of the first metal part 111.

[0043] The spacing of the gap is W1, which satisfies: W1≤0.1mm.

[0044] It can be understood that the metal materials are not the same, the corresponding material fluidity is not the same. Therefore, the material of the first metal piece 111 and the material of the second metal piece 112 are not the same. Wherein, the material fluidity refers to the ability of the metal material to fill the surrounding gap or space during casting or forging or stamping.

[0045] It can be understood that the first metal piece 111 and the second metal piece 112 are arranged along the axial direction of the pole column 011. The shape of the cross section of the pole column 011 can be circular, triangular, rectangular or polygonal.

[0046] It can be understood that the pole column 011 is formed by swaging, so as to extrude the second metal piece 112 to the first metal piece 111, thereby forming the first recess 1112 on the first metal piece 111, and forming the second protrusion 1122 embedded in the first recess 1112 on the second metal piece 112, and at the same time, extruding the first metal piece 111 to the second recess 1123 to form the first protrusion 1113 embedded in the second recess 1123.

[0047] Exemplarily, the first metal is electrically connected with the current collector, the current collector is copper material, correspondingly, the first metal is copper material, and the second metal is aluminum material, which is connected with the terminal 012; it can also be that the second metal is electrically connected with the current collector, the second metal is copper material, correspondingly, the first metal can be aluminum material, which is connected with the terminal 012.

[0048] In the embodiment, by setting the first protrusion 1113 embedded in the second recess 1123 and the second protrusion 1122 embedded in the first recess 1112, the structure that the first metal piece 111 and the second metal piece 112 are embedded in each other can be formed, so as to ensure the reliability of the combination of the two metal materials; and by embedding one end of the second metal piece 112 with better material fluidity into the first metal piece 111, when the pole column 011 is formed by swaging, the second metal piece 112 with better material fluidity can extrude the first metal piece 111 to form a larger extrusion surface of the second metal piece 112 extruding the first metal piece 111. In this way, the extrusion force between the two metal materials can be ensured based on the better fluidity of the second metal piece 112, so as to reduce the gap of the combination surface between the second metal piece 112 and the first metal piece 111, and improve the current-carrying capacity of the pole column.

[0049] Please refer to Figure 4 In an embodiment, the first surface 1124 includes a top surface 1125 and a transition surface 1126. One side of the transition surface 1126 is connected with one side of the top surface 1125 close to the axis of the pole column 011, and the other side is smoothly transitioned to the bottom wall of the second recess 1123.

[0050] Exemplarily, the top surface 1125 is perpendicular to the axis of the pole column 011.

[0051] In this embodiment, through the above arrangement, on the one hand, the contact surface between the first metal part 111 and the second metal part 112 can be increased through the transition surface 1126 to improve the current carrying capacity of the pole 011; on the other hand, stress concentration can be improved to improve the reliability of the pole 011.

[0052] See also Figure 3 In one embodiment, along the radial direction of the pole 011 , the end of the second protrusion 1122 away from the main body 1121 has a first radius R1 , and the main body 1121 has a second radius R2 , satisfying: R1 > R2 .

[0053] In this embodiment, by limiting the first radius R1 to be larger than the second radius R2, the second protrusion 1122 can have a larger radial dimension, thereby increasing the mating surface between the second protrusion 1122 and the first recess 1112. In this way, the area of ​​the bonding surface between the first metal member 111 and the second metal member 112 can be increased, thereby improving the reliability of the bonding between the first metal member 111 and the second metal member 112.

[0054] Furthermore, by limiting the first radius R1 to be larger than the second radius R2, more second metal members 112 can be contained within the first metal member 111 while maintaining a constant outer area of ​​the first metal member 111, thereby reducing the material usage of the first metal member 111. Thus, by selecting copper for the first metal member 111 and aluminum for the second metal member 112, material costs can be effectively controlled, as well as the weight of the pole 011.

[0055] See also Figure 3 In one embodiment, the difference between the first radius R1 and the second radius R2 is ΔR, which satisfies: 40% R2≤ΔR≤60% R2.

[0056] It will be appreciated that the difference ΔR includes but is not limited to 40% R2, 42% R2, 45% R2, 47% R2, 49% R2, 50% R2, 53% R2, 55% R2, 57% R2, 58% R2, 59% R2, and 60% R2.

[0057] For example, taking the second radius R2 as 4 mm, the difference ΔR includes but is not limited to 1.6 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, and 2.4 mm.

[0058] In this embodiment, by limiting the difference between the first radius R1 and the second radius R2, on the one hand, it is possible to avoid the radial dimension of the second protrusion 1122 being too large, which would result in a higher difficulty in forming it, thereby controlling its manufacturing cost; on the other hand, it is possible to avoid the radial dimension of the second protrusion 1122 being too small, which would affect the reliability of the connection between the first metal part 111 and the second metal part 112.

[0059] See also Figure 5 , Figure 5 It is along Figure 3 Cross-sectional view along line BB. In one embodiment, the second recess 1123 extends in an annular structure around the axis of the terminal 011. The first protrusion 1113 extends in an annular structure around the axis of the terminal 011. This increases the area of ​​the mating surface between the first protrusion and the second recess 1123, thereby increasing the area of ​​the bonding surface between the first metal member 111 and the second metal member 112, thereby improving the reliability of the bonding between the first metal member 111 and the second metal member 112.

[0060] See also Figure 6 , Figure 6 FIG2 is a schematic structural diagram of a first metal member 111 provided in an embodiment of the present application. In one embodiment, the first protrusion 1113 includes a radially extending portion 1114 and an axially extending portion 1115. The radially extending portion 1114 is radially inwardly disposed from the inner wall of the first recess 1112, near the opening thereof. The radially extending portion 1114 has a top end surface 1116 facing away from the bottom wall of the first recess 1112. The axially extending portion 1115 extends from the top end surface 1116 in a direction away from the bottom wall of the first recess 1112.

[0061] It can be understood that the radius of the outer circumference of the first protrusion 1113 is smaller than the radius of the outer circumference of the first metal component 111 .

[0062] In this embodiment, by setting the first protrusion 1113 to a structure including a radial extension portion 1114 and an axial extension portion 1115, the fitting surface between the first protrusion 1113 and the second recess 1123 can be increased, thereby increasing the reliability of the connection between the first metal part 111 and the second metal part 112.

[0063] See also Figure 3 In one embodiment, the outer circumference of the first protrusion is co-circumferential with the outer circumference of the main body. Specifically, the radius of the outer circumference of the extension 1115 is consistent with the radius of the main body 1121. This allows the outer surface structure of the terminal 011 to be regular, facilitating the connection between the terminal 011 and other components.

[0064] In one embodiment, the first metal member 111 is made of copper, and the second metal member 112 is made of aluminum. The negative electrode current collector is made of copper, with the first metal member 111 connected to the negative electrode current collector, and the second metal member 112 connected to the terminal 012. This ensures that the terminal 011 meets the low resistance requirement during overcurrent, reducing power loss, while also controlling the material cost of the terminal 011 and improving its economic efficiency.

[0065] In addition, copper materials include but are not limited to pure copper, brass, bronze, phosphor bronze, beryllium copper, and oxygen-free copper.

[0066] Aluminum materials include but are not limited to 1070 aluminum plate, 1060 aluminum plate, and L3 aluminum plate.

[0067] In one embodiment, the edges of the pole 011 are all provided with rounded corners. This can avoid stress concentration caused by the sharp corners of the pole 011, thereby improving the stress state of the pole 011 and preventing the pole 011 from scratching other components during installation.

[0068] See also Figure 7 , Figure 7 : is a structural schematic diagram of the cover assembly 002 provided in an embodiment of the present application. Accordingly, an embodiment of the present application also provides a cover assembly 002. The cover assembly 002 includes a cover 021, an upper plastic part 022, a lower plastic part 023, a current collecting part 024, a sealing ring and the aforementioned pole 011. The pole 011 is passed through the cover 021. The terminal 012 is located on one side of the cover 021. The upper plastic part 022 is arranged between the terminal 012 and the cover 021. The lower plastic part 023 is arranged on the other side of the cover 021. One end of the current collecting part 024 is connected to the end of the pole 011 away from the terminal 012. The sealing ring is arranged between the pole 011 and the mounting hole.

[0069] In this embodiment, by adopting the aforementioned terminal post 011, the interlocking structure of the first metal member 111 and the second metal member 112 can be used to increase the area of ​​the joint surface between the first metal member 111 and the second metal member 112, thereby improving the reliability of the joint between the first metal member 111 and the second metal member 112. In this way, the terminal post 011 is structurally reliable, thereby improving the structural stability of the cover plate assembly 002.

[0070] Accordingly, embodiments of the present application also provide a battery cell. The battery cell includes a housing, an electrode assembly, and the aforementioned cover plate assembly 002. The housing has a receiving cavity. The electrode assembly is disposed within the receiving cavity. A cover plate 021 is connected to the housing and seals the opening of the receiving cavity. The other end of a current collector 024 is connected to the electrode assembly.

[0071] The electrode assembly includes at least a positive electrode sheet, a separator and a negative electrode sheet that are stacked.

[0072] It can be understood that the pole post 011 is connected with the negative plate of the battery cell through the current collector 024.

[0073] In the embodiment, by adopting the cover plate assembly 002, the reliability of the battery cell can be improved, so that the pole post 011 meets the overcurrent requirement of the battery cell, and the cost can be controlled, and the economy of the battery cell is improved.

[0074] The embodiments of the application are described in detail above, and specific examples are applied in this paper to describe the principles and implementation modes of the application. The above description of the embodiments is only used to help understand the method of the application and its core idea; at the same time, for those skilled in the art, according to the idea of the application, the specific implementation mode and application range will be changed; in summary, the content of the specification should not be understood as a limitation of the application.

Claims

1. A pole, characterized in that: include: The first metal member has a first recess, and a first protrusion is provided on an inner wall of the first recess near an opening thereof; a second metal member comprising a main body and a second protrusion connected to each other, a second recess being provided on an outer peripheral surface of the second protrusion, the second protrusion being engaged with the first recess, and the first protrusion being engaged with the second recess, and a first surface being formed on a side of the second recess away from a bottom wall of the first recess; There is a gap between the first metal member and the second metal member only between the first protrusion and the first surface, and the material fluidity of the second metal member is greater than the material fluidity of the first metal member.

2. The pole according to claim 1, characterized in that The first surface includes a top surface and a transition surface. One side of the transition surface is connected to a side of the top surface close to the axis of the pole, and the other side smoothly transitions to the bottom wall of the second recess.

3. The pole according to claim 1, characterized in that The spacing of the gap is W1, which satisfies: W1≤0.1mm.

4. The pole according to claim 1, characterized in that Along the radial direction of the pole, an end of the second protrusion away from the main body has a first radius R1, and the main body has a second radius R2, satisfying: R1>R2.

5. The pole according to claim 4, characterized in that: The difference between the first radius R1 and the second radius R2 is ΔR, which satisfies the following: 40% R2≤ΔR≤60% R2.

6. The pole according to any one of claims 1 to 5, characterized in that: The second concave portion extends around the axis of the pole to form an annular structure, and the first convex portion extends around the axis of the pole to form an annular structure.

7. The pole according to any one of claims 1 to 5, characterized in that: The first protrusion includes a radial extension portion and an axial extension portion. The radial extension portion is radially inwardly arranged from the inner wall of the first recess near its opening, and the radial extension portion has a top end surface facing away from the bottom wall of the first recess. The axial extension portion extends from the top end surface in a direction away from the bottom wall of the first recess.

8. The pole according to claim 7, characterized in that The radius of the outer peripheral surface of the axially extending portion is consistent with the radius of the main body portion.

9. The pole according to any one of claims 1 to 5, characterized in that: The outer circumferential surface of the first protrusion is cocircumferentially arranged with the outer circumferential surface of the main body.

10. The pole according to any one of claims 1 to 4, characterized in that: The first metal component is made of copper, and the second metal component is made of aluminum.

11. A cover plate assembly, characterized in that: include: cover; The pole according to any one of claims 1 to 10, wherein the pole is provided through the cover plate; A terminal is located on one side of the cover plate and connected to the pole; an upper plastic part, disposed between the terminal and the cover plate; a lower plastic part, arranged on the other side of the cover; a current collector, one end of which is connected to an end of the pole away from the terminal; A sealing ring is provided between the pole and the mounting hole; In which, the material of the first metal part is consistent with the material of the current collecting part, the first metal part is connected to one end of the current collecting part, and the terminal is connected to the second metal part, or the material of the second metal part is consistent with the material of the current collecting part, the second metal part is connected to one end of the current collecting part, and the terminal is connected to the first metal part.

12. A battery cell, characterized in that: include: A housing having a receiving cavity; an electrode assembly, disposed in the accommodating cavity; And, in the cover plate assembly according to claim 11, the cover plate is connected to the shell and closes the opening of the accommodating cavity, and the other end of the current collecting member is connected to the electrode assembly.

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