Polar posts, cover plate assemblies, and battery cells

Abstract

This application provides a pole, a cover plate assembly, and a battery cell, the pole comprising a first metal member 111 and a second metal member 112. The first metal member comprises a first recess, the inner wall of which is provided a first protrusion. The second metal member comprises a body and a second protrusion connected to each other, the outer circumferential surface of the second protrusion being provided with a second recess, the second protrusion fitting into the first recess, and the first protrusion fitting into the second recess. The side of the second recess furthest from the bottom wall of the first recess is the first surface, and there is a gap only between the first protrusion and the first surface. [Effect] The second metal member, which has excellent material fluidity, presses against the first metal member, creating a larger pressing surface between the second metal member and the first metal member. In this way, by utilizing the excellent material fluidity of the second metal member and ensuring the pressing force between the two metal materials, the gap at the bonding surface between the second metal member and the first metal member is reduced, improving the current tolerance capacity of the pole.

Description

Technical Field

[0001] This application claims priority based on a Chinese application with application number 202422198546.4 filed on September 6, 2024, and incorporates by reference all the descriptions contained in that application. This application relates to the technical field of batteries, specifically to pole posts, cover plate assemblies, and battery cells.

Background Art

[0002] The pole post is an important component that connects the inside and outside of the battery cell. One end of the pole post is connected to the external circuit of the battery cell, and the other end is connected to the internal cell of the power battery. In order to reduce costs and weight, an aluminum material is used for current transmission in the external circuit of the battery cell. However, inside the battery cell, the materials of the negative electrode current collector member and the current collector member of the negative electrode sheet are also copper materials. Therefore, in order to improve the conductivity of the pole post and suppress the weight and cost of the battery cell, a copper-aluminum composite pole post is used to connect the negative electrode current collector member to the external circuit. The copper material of the copper-aluminum composite pole post is connected to the negative electrode current collector member, and the aluminum material of the copper-aluminum composite pole post is connected to the external circuit.

[0003] In order to ensure the reliability of the bond between the copper material and the aluminum material, an interlock structure is installed in the related art. However, since the interlock structure is formed by pressing, the area of the bonding surface between the copper material and the aluminum material is small, and the current-carrying capacity of the pole post decreases.

Summary of the Invention

[0004] Embodiments of this application provide a pole post, a cover plate assembly, and a battery cell with improved current-carrying capacity.

[0005] In a first embodiment, the present invention provides a pole column comprising a first metal member and a second metal member. The first metal member comprises a first recess, and a first protrusion is provided on the inner wall of the first recess on the side closer to the opening of the first recess. The second metal member comprises a body and a second protrusion connected to each other, with a second recess provided on the outer circumferential surface of the second protrusion, the second protrusion fitting into the first recess, and the first protrusion fitting into the second recess. The side of the second recess furthest from the bottom wall of the first recess is the first surface. Here, 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 that of the first metal member.

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

[0007] In one embodiment, the gap spacing is W1, and the condition W1 ≤ 0.1 mm is satisfied.

[0008] In one embodiment, along the radial direction of the pole column, the end of the second protrusion furthest from the main body has a first radius R1, the main body has a second radius R2, and the condition R1 > R2 is satisfied.

[0009] In one embodiment, the difference between the first radius R1 and the second radius R2 is ΔR, and the condition 40%R2 ≤ ΔR ≤ 60%R2 is satisfied.

[0010] In one embodiment, the second recess extends to form an annular structure around the axis of the pole column, and the first protrusion extends to form an annular structure around the axis of the pole column.

[0011] In one embodiment, the first protrusion includes a radially extending portion and an axially extending portion, the radially extending portion extending radially inward from the side of the inner wall of the first recess closest to the opening of the first recess, the radially extending portion having a top end face opposite to the bottom wall of the first recess, and the axially extending portion extending from the top end face in a direction away from the bottom wall of the first recess.

[0012] In one embodiment, the radius of the outer circumferential surface of the axially extending portion is the same as the radius of the main body portion.

[0013] In one embodiment, the outer surface of the first protrusion and the outer surface of the main body are arranged on the same circumference.

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

[0015] In a second embodiment, the present invention provides a cover plate assembly comprising a cover plate, an upper plastic member, a lower plastic member, a current collector member, a sealing ring, and the aforementioned pole post. The pole post is mounted through the cover plate, and the terminals are located on one side of the cover plate. The upper plastic member is provided between the terminals and the cover plate. The lower plastic member is provided on the other side of the cover plate. One end of the current collector member is connected to the end of the pole post furthest from the terminals. The sealing ring is provided between the pole post and the mounting hole.

[0016] In a third aspect, an embodiment of the present invention provides a battery cell comprising a housing, an electrode assembly, and the aforementioned cover plate assembly. The housing has a housing cavity. The electrode assembly is provided in the housing cavity. The cover plate is connected to the housing and closes the opening of the housing cavity, and the other end of the current collector member is connected to the electrode assembly. [Effects of the Invention]

[0017] In the embodiment of the present application, the first convex portion is fitted into the second recess, and the second convex portion is fitted into the first recess, thereby forming a structure in which the first metal member and the second metal member are fitted together, and ensuring the reliability of the bond between the two metal materials. Furthermore, by fitting one end of the second metal member, which has excellent material fluidity, to the first metal member, when forming the pole column by cold forging, the second metal member, which has excellent material fluidity, can press against the first metal member, and a larger pressing surface can be formed between the second metal member and the first metal member. In this way, by utilizing the excellent material fluidity of the second metal member and ensuring the pressing force between the two metal materials, the gap at the bonding surface between the second metal member and the first metal member is reduced, and the current tolerance capacity of the pole column is improved. [Brief explanation of the drawing]

[0018] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used to describe the embodiments are briefly introduced below. Clearly, the drawings described below represent only a few embodiments of this application. Those skilled in the art can obtain other drawings based on these without any creative effort.

[0019] [Figure 1] This is a structural diagram of the pole column according to an embodiment of the present invention. [Figure 2] This is a plan view of the pole column according to an embodiment of the present invention. [Figure 3] This is a cross-sectional view taken along line AA in Figure 2. [Figure 4] This is an enlarged view of area C in Figure 3. [Figure 5] This is a cross-sectional view taken along line BB in Figure 3. [Figure 6] This is a structural diagram of the first metal member according to an embodiment of the present application. [Figure 7] This is a structural diagram of a cover plate assembly according to an embodiment of the present application. [Modes for carrying out the invention]

[0020] The technical solutions according to the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor are included in the protection scope of the present application.

[0021] It should be understood that the specific embodiments described in this specification are only used for explaining and interpreting the present application and are not intended to limit the present application. In the present application, the terms "first" and "second" are only used for explanatory purposes and should not be understood as indicating or implying relative importance or implicitly designating the number of technical features. Therefore, the features limited by "first" or "second" may explicitly or implicitly include one or more of the aforementioned features.

[0022] In addition, in the description of the present application, the terms "attachment", "connection", and "connection" should be understood in a broad sense unless otherwise clearly defined and limited. For example, it may be a fixed connection, a detachable connection, or an integral connection. It may be a mechanical connection, an electrical connection, or mutual communication. It may be a direct connection, an indirect connection through an intermediate medium, or an internal connection between two elements or an interaction relationship between two elements. For those skilled in the art, the specific meanings of the aforementioned terms in the present application can be understood according to specific situations.

[0023] Moreover, in this specification, the terms "including", "comprising", or other variations thereof are intended to cover non-exclusive inclusion. Therefore, a product including a series of elements not only includes those elements but also includes other elements not explicitly listed.

[0024] In the description of embodiments of this Application, words such as “exemplary” or “for example” are used to indicate examples, descriptions, or descriptions. Any embodiment or design described as “exemplary” or “for example” in the embodiments of this Application should not be construed as being preferable or advantageous to other embodiments or designs. The use of words such as “exemplary” or “for example” is intended to clearly present relative concepts.

[0025] Before introducing the poles, cover plate assemblies, and battery cells provided in this application, we will first introduce relevant background information regarding the embodiments of this application.

[0026] To ensure the reliability of the connection between the copper and aluminum materials of the pole column, related technologies form multiple interlock structures by installing aluminum material pressed against copper and copper material pressed against aluminum material at multiple connection points between the copper and aluminum materials. Since copper has better conductivity than aluminum, the ends of the aluminum material are coated with copper, and the copper material presses against the ends of the aluminum material, causing the ends of the aluminum material to be recessed, and a structure is formed in which the copper material fits into the aluminum material at one end of the pole column. This results in a high proportion of structures in which copper is pressed against aluminum material.

[0027] However, copper has low material fluidity, and when copper is pressed against aluminum, the pressure exerted by the copper against the aluminum is insufficient. This results in a large gap between the copper and aluminum in the interlock structure formed by the copper pressing against the aluminum, reducing the current tolerance of the pole.

[0028] Based on this, in order to ensure the reliability of the bond between copper and aluminum materials while improving the current tolerance between them, embodiments of the present invention provide poles, cover plate assemblies, and battery cells, each of which will be described in detail below.

[0029] Refer to Figures 1 to 4. Figure 1 is a structural diagram of pole column 011 according to an embodiment of the present application, Figure 2 is a plan view of pole column 011 according to an embodiment of the present application, Figure 3 is a cross-sectional view taken along line AA in Figure 2, and Figure 4 is an enlarged view of location C in Figure 3. The embodiment of the present application provides pole column 011. The pole column 011 comprises a first metal member 111 and a second metal member 112. The first metal member 111 comprises a first recess 1112. A first protrusion 1113 is provided on the inner wall of the first recess 1112, on the side closer to the opening of the first recess. The second metal member 112 comprises a connected body 1121 and a second protrusion 1122. A second recess 1123 is provided on the outer circumferential surface of the second protrusion 1122. The second protrusion 1122 is fitted into the first recess 1112. The first protrusion 1113 is fitted into the second recess 1123. The side of the second recess 1123 furthest from the bottom wall of the first recess 1112 is the first surface 1124. Between the first metal member 111 and the second metal member 112, there is a gap only between the first protrusion 1113 and the first surface 1124, and the material flowability of the second metal member 112 is greater than that of the first metal member 111.

[0030] Here, the gap is W1, and the condition W1 ≤ 0.1 mm is satisfied.

[0031] It can be seen that different metal materials result in different material fluidity. Therefore, the material of the first metal member 111 is different from the material of the second metal member 112. Here, material fluidity refers to the ability of a metal material to fill surrounding gaps and spaces during casting, forging, and punching.

[0032] The first metal member 111 and the second metal member 112 are arranged in the axial direction of the pole column 011. The cross-sectional shape of the pole column 011 may be circular, triangular, rectangular, or polygonal.

[0033] As can be seen, the pole column 011 is formed by cold forging, and the second metal member 112 is pressed against the first metal member 111, so that the first recess 1112 is formed in the first metal member 111, the second protrusion 1122 that fits into the first recess 1112 is formed in the second metal member 112, and the first metal member 111 is pressed against the second recess 1123 to form the first protrusion 1113 that fits into the second recess 1123.

[0034] For example, the first metal is electrically connected to a copper current collector, and accordingly, the first metal is made of copper, and the second metal is made of aluminum and connected to terminal 012. Alternatively, the second metal may be electrically connected to a copper current collector, and accordingly, the first metal may be made of aluminum and connected to terminal 012.

[0035] In this embodiment, the first protrusion 1113 is fitted into the second recess 1123, and the second protrusion 1122 is fitted into the first recess 1112, thereby forming a structure in which the first metal member 111 and the second metal member 112 are fitted together, and ensuring the reliability of the bond between the two metal materials. Furthermore, by fitting one end of the second metal member 112, which has excellent material fluidity, to the first metal member 111, when forming the pole column 011 by press forming, the second metal member 112, which has excellent material fluidity, can press against the first metal member 111, and a larger pressing surface can be formed between the second metal member 112 and the first metal member 111. In this way, by utilizing the excellent material fluidity of the second metal member 112 and ensuring the pressing force between the two metal materials, the gap at the bonding surface between the second metal member 112 and the first metal member 111 is reduced, and the current tolerance capacity of the pole column is improved.

[0036] As shown in Figure 4, in one embodiment, the first surface 1124 includes an upper surface 1125 and a transition surface 1126. One side of the transition surface 1126 is connected to the side of the upper surface 1125 closer to the axis of the pole column 011, and the other side of the transition surface 1126 smoothly transitions to the bottom wall of the second recess 1123.

[0037] For example, the upper surface 1125 is perpendicular to the axis of pole column 011.

[0038] In this embodiment, the above arrangement increases the contact surface between the first metal member 111 and the second metal member 112 via the transition surface 1126, thereby improving the current tolerance of the pole column 011. On the other hand, stress concentration is reduced, thus improving the reliability of the pole column 011.

[0039] Refer to Figure 3. In one embodiment, along the radial direction of the pole column 011, the end of the second protrusion 1122 furthest from the main body 1121 has a first radius R1, and the main body 1121 has a second radius R2, satisfying the condition R1 > R2.

[0040] In this embodiment, by limiting the first radius R1 to be larger than the second radius R2, the radial dimension of the second protrusion 1122 is increased, thereby expanding the fitting surface between the second protrusion 1122 and the first recess 1112. In this way, by increasing the area of ​​the bonding surface between the first metal member 111 and the second metal member 112, the reliability of the bond between the first metal member 111 and the second metal member 112 can be improved.

[0041] Furthermore, by limiting the first radius R1 to be larger than the second radius R2, it is possible to accommodate more second metal members 112 inside the first metal member 111 while keeping the outer surface area of ​​the first metal member 111 constant, thereby reducing the amount of material used for the first metal member 111. As a result, when copper is selected as the first metal member 111 and aluminum is selected as the second metal member 112, material costs and the weight of the pole column 011 can be effectively suppressed.

[0042] Referring to Figure 3, in one embodiment, the difference between the first radius R1 and the second radius R2 is ΔR, satisfying the condition 40%R2 ≤ ΔR ≤ 60%R2.

[0043] 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.

[0044] For example, if the second radius R2 is 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.

[0045] 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 second protrusion 1122 becoming too large in its radial dimension, making its formation difficult, and thereby suppressing its manufacturing cost. On the other hand, it is possible to avoid the second protrusion 1122 becoming too small in its radial dimension, which would affect the reliability of the connection between the first metal member 111 and the second metal member 112.

[0046] Referring to Figure 5, which is a cross-sectional view taken along line BB in Figure 3. In one embodiment, the second recess 1123 extends to form an annular structure around the axis of the pole column 011. The first protrusion 1113 extends to form an annular structure around the axis of the pole column 011. In this way, by increasing the area of ​​the fitting surface between the first protrusion and the second recess 1123, the area of ​​the fitting surface between the first metal member 111 and the second metal member 112 can be increased, thereby improving the reliability of the connection between the first metal member 111 and the second metal member 112.

[0047] Refer to Figure 6. Figure 6 is a structural diagram of the first metal member 111 according to 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, wherein the radially extending portion 1114 extends radially inward from the side of the inner wall of the first recess 1112 that is close to the opening of the first recess 1112, the radially extending portion 1114 has a top end face 1116 opposite to the bottom wall of the first recess 1112, and the axially extending portion 1115 extends from the top end face 1116 in a direction away from the bottom wall of the first recess 1112.

[0048] It will be understood that the radius of the outer surface of the first protrusion 1113 is smaller than the radius of the outer surface of the first metal member 111.

[0049] In this embodiment, the first protrusion 1113 is configured to include a radially extending portion 1114 and an axially extending portion 1115, thereby increasing the fitting surface between the first protrusion 1113 and the second recess 1123, and thereby improving the reliability of the connection between the first metal member 111 and the second metal member 112.

[0050] Referring to Figure 3, in one embodiment, the outer surface of the first protrusion and the outer surface of the main body are arranged on the same circumference. Specifically, the radius of the outer surface of the extended portion 1115 is the same as the radius of the main body 1121. This makes the outer surface structure of the pole column 011 uniform, and makes it easier to combine the pole column 011 with other parts.

[0051] In one embodiment, the material of the first metal member 111 is copper, and the material of the second metal member 112 is aluminum. Here, the negative electrode current collector disc is made of copper, the first metal member 111 is connected to the negative electrode current collector disc, and the second metal member 112 is connected to the terminal 012. In this way, the requirement for low resistance of the pole post 011 when current passes through is met, electrical energy loss is reduced, and the material cost of the pole post 011 is kept down, improving the economic efficiency of the pole post 011.

[0052] Furthermore, copper materials include, but are not limited to, pure copper, brass, bronze, phosphor bronze, beryllium bronze, and oxygen-free copper.

[0053] The aluminum material includes, but is not limited to, 1070 aluminum sheet, 1060 aluminum sheet, and L3 aluminum sheet.

[0054] In one embodiment, all edges of the pole column 011 are rounded. This prevents stress concentration due to sharp corners of the pole column 011, improves the stress state of the pole column 011, and prevents the pole column 011 from scratching other parts during installation.

[0055] Referring to Figure 7, Figure 7 is a structural diagram of a cover plate assembly 002 according to an embodiment of the present application. Accordingly, embodiments of the present application further provide a cover plate assembly 002. The cover plate assembly 002 comprises an upper plastic member 022, a lower plastic member 023, a current collector member 024, a sealing ring, and a pole post 011. The pole post 011 is mounted through the cover plate 021. The terminal 012 is located on one side of the cover plate 021. The upper plastic member 022 is provided between the terminal 012 and the cover plate 021. The lower plastic member 023 is provided on the other side of the cover plate 021. One end of the current collector member 024 is connected to the end of the pole post furthest from the terminal 012. The sealing ring is provided between the pole post 011 and the mounting hole.

[0056] In this embodiment, by using the pole post 011 described above, the area of ​​the bonding surface between the first metal member 111 and the second metal member 112 can be increased based on the structure in which the first metal member 111 and the second metal member 112 fit together, thereby improving the reliability of the bond between the first metal member 111 and the second metal member 112. As a result, the structure of the pole post 011 becomes more reliable, and the structural stability of the cover plate assembly 002 is improved.

[0057] Accordingly, embodiments of the present invention further provide a battery cell comprising a housing, an electrode assembly, and the aforementioned cover plate assembly 002. The housing has a housing cavity. The electrode assembly is provided in the housing cavity, and a cover plate 021 is connected to the housing and seals the opening of the housing cavity. The other end of the current collector member 024 is connected to the electrode assembly.

[0058] Here, the electrode assembly comprises at least a stacked positive electrode sheet, a separator, and a negative electrode sheet.

[0059] To make it easier to understand, the pole 011 is connected to the negative electrode sheet of the battery cell via the current collector 024.

[0060] In this embodiment, by employing the aforementioned cover plate assembly 002, the reliability of the battery cell can be improved, the pole 011 can meet the current tolerance requirements of the battery cell, and at the same time, costs can be reduced, which is advantageous in improving the economic efficiency of the battery cell.

[0061] The display panel and display device according to the embodiments of the present application have been described in detail above. While this specification has used specific examples to illustrate the principles and embodiments of the present application, the above-described embodiments are intended solely as reference for understanding the methods and core concepts of the present application. Furthermore, while those skilled in the art may modify the embodiments and scope of application according to the concept of the present application, in summary, the contents of this specification should not be understood as limitations on the present application. [Explanation of Symbols]

[0062] 011 Pole Pillar 111 First metal component 1112 First recess 1113 First protrusion 1114 Radial extension section 1115 Axial extension 1116 Top end face 112 Second metal member 1121 Main Unit 1122 Second protrusion 1123 Second recess 1125 1st surface 1125 Top surface 1126 Transition plane 012 Terminal 002 Cover Plate Assembly 021 Cover Plate 022 Upper plastic component 023 Lower plastic component 024 Current collector

Claims

1. A pole column comprising a first metal member and a second metal member, The first metal member is provided with a first recess, and a first protrusion is provided on the inner wall of the first recess on the side closer to the opening of the first recess. The second metal member comprises a body and a second protrusion connected to each other, a second recess provided on the outer circumferential surface of the second protrusion, the second protrusion fitted into the first recess, the first protrusion fitted into the second recess, and the side of the second recess furthest from the bottom wall of the first recess is the first surface. A pole column characterized in that 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 that of the first metal member.

2. The pole column according to claim 1, characterized in that the first surface includes an upper surface and a transition surface, one side of the transition surface is connected to the side of the upper surface closer to the axis of the pole column, and the other side of the transition surface smoothly transitions to the bottom wall of the second recess.

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

4. The pole column according to claim 1, characterized in that, along the radial direction of the pole column, the end of the second protrusion furthest from the main body has a first radius R1, the main body has a second radius R2, and R1 > R2.

5. The pole column according to claim 4, characterized in that the difference between the first radius R1 and the second radius R2 is ΔR, and the condition 40%R2 ≤ ΔR ≤ 60%R2 is satisfied.

6. The pole column according to any one of claims 1 to 5, characterized in that the second recess extends to form an annular structure around the axis of the pole column, and the first protrusion extends to form an annular structure around the axis of the pole column.

7. The pole column according to any one of claims 1 to 5, characterized in that the first protrusion includes a radially extending portion and an axially extending portion, the radially extending portion extends radially inward from the side of the inner wall of the first recess that is close to the opening of the first recess, the radially extending portion has a top end face opposite to the bottom wall of the first recess, and the axially extending portion extends from the top end face in a direction away from the bottom wall of the first recess.

8. The pole column according to claim 7, characterized in that the radius of the outer circumferential surface of the axially extending portion is the same as the radius of the main body portion.

9. The pole column according to any one of claims 1 to 5, characterized in that the outer circumferential surface of the first protrusion and the outer circumferential surface of the main body are arranged on the same circumference.

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

11. A cover plate assembly, Cover plate and A pole post according to any one of claims 1 to 5, which is inserted through the cover plate, A terminal located on one side of the cover plate and connected to the pole post, An upper plastic member provided between the terminal and the cover plate, A lower plastic member provided on the other side of the cover plate, A flow collector member, one end of which is connected to the end of the pole column furthest from the terminal, The system includes a sealing ring provided between the pole post and the mounting hole. A cover plate assembly characterized in that the material of the first metal member is the same as the material of the current collector, the first metal member is connected to one end of the current collector, and the terminal is connected to the second metal member, or the material of the second metal member is the same as the material of the current collector, the second metal member is connected to one end of the current collector, and the terminal is connected to the first metal member.

12. It is a battery cell, A housing having an enclosure, An electrode assembly provided in the aforementioned housing cavity, The cover plate assembly is as described in claim 11, A battery cell characterized in that the cover plate is connected to the housing and seals the opening of the housing cavity, and the other end of the current collector is connected to the electrode assembly.

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