Copper-aluminum composite pole and battery cover plate

Abstract

The present application relates to the technical field of batteries, and in particular to a copper-aluminum composite pole and a battery cover plate. The copper-aluminum composite pole comprises a copper layer portion and an aluminum layer portion, the copper-aluminum composite pole comprises a cylindrical structure and a plate structure, and the plate structure is integrally connected to one end of the cylindrical structure in a first direction. The plate structure and a first portion of the cylindrical structure are the copper layer portion, the first portion is the portion at the end of the cylindrical structure close to the plate structure, and a second portion of the cylindrical structure is the aluminum layer portion. The size of the first portion in the first direction is greater than or equal to 0.2 mm. In the copper-aluminum composite pole and the battery cover plate provided by the present application, the copper layer portion and the aluminum layer portion of the copper-aluminum composite pole are stably bonded, thereby ensuring that the copper-aluminum composite pole maintains a stable structure under vibration and bumping working conditions.

Description

Copper-aluminum composite terminals and battery cover

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. CN202510180610.2, filed on February 19, 2025, entitled "Copper-Aluminum Composite Terminal and Battery Cover", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a copper-aluminum composite electrode and battery cover. Background Technology

[0004] Currently, the negative electrode post of batteries is usually designed as a copper-aluminum composite structure to ensure its welding performance. However, in current copper-aluminum composite electrode posts, the ratio between the copper layer and the aluminum layer is difficult to determine. If the proportion of the copper layer is too high, it greatly increases the manufacturing cost of the negative electrode post; if the proportion of the copper layer is insufficient, it is very easy to cause poor connection stability between the copper layer and the aluminum layer of the negative electrode post. Under the condition of vibration and bumps, the negative electrode post is very likely to break at the interface of the copper-aluminum composite.

[0005] Public content

[0006] In view of this, the purpose of this application is to provide a copper-aluminum composite electrode post and battery cover plate, so as to solve to a certain extent the technical problems existing in the prior art. In the current copper-aluminum composite electrode post, it is difficult to determine the ratio between the copper layer and the aluminum layer of the negative electrode post. If the proportion of the copper layer is too high, it will greatly increase the manufacturing cost of the negative electrode post. If the proportion of the copper layer is insufficient, it will easily lead to poor connection stability between the copper layer and the aluminum layer of the negative electrode post. Under the condition of vibration and bumps, the negative electrode post is very likely to break at the interface of the copper-aluminum composite.

[0007] In a first aspect, this application provides a copper-aluminum composite electrode post, which includes a copper layer and an aluminum layer, and the copper-aluminum composite electrode post includes a column structure and a plate structure, wherein the plate structure is integrally connected to one end of the column structure in a first direction.

[0008] Wherein, the first part of both the plate structure and the column structure is the copper layer, the first part is disposed at one end of the column structure near the plate structure, and the second part of the column structure is the aluminum layer;

[0009] The dimension of the first part in the first direction is greater than or equal to 0.2 mm.

[0010] Beneficial effects: The copper-aluminum composite pole provided in this application extends the copper layer from the plate structure to the column structure, and the extension length of the copper layer on the column structure, that is, the dimension of the first part in the first direction (i.e., the h value shown in Figure 2) is greater than or equal to 0.2 mm. The copper layer and aluminum layer of the copper-aluminum composite pole are stably combined, which can ensure that the copper-aluminum composite pole maintains structural stability under vibration and bump conditions.

[0011] In some embodiments, in the first direction, the dimension of the first portion in the first direction is less than or equal to 0.7 mm.

[0012] In some embodiments, the column structure is a cylinder, and the outer diameter of the column structure is greater than or equal to 5 mm.

[0013] In some embodiments, the outer diameter of the column structure is less than or equal to 15 mm.

[0014] In some embodiments, the copper-aluminum composite pole is a copper-aluminum friction welded part or a copper-aluminum roll-formed composite part.

[0015] In some embodiments, the operating temperature of the copper-aluminum composite electrode is less than or equal to 350°C.

[0016] Secondly, this application provides a battery cover plate, including a cover plate body and a negative electrode post assembly. The negative electrode post assembly includes a negative electrode riveting block and a copper-aluminum composite electrode post as described in any of the above embodiments. Therefore, it has all the beneficial technical effects of the copper-aluminum composite electrode post, which will not be repeated here.

[0017] In some embodiments, the column structure of the copper-aluminum composite electrode extends through the cover plate body along the first direction and is connected to the negative electrode riveting block.

[0018] In some embodiments, a positive electrode post assembly is further included, the positive electrode post assembly including a positive electrode post and a positive electrode riveting block, a portion of the positive electrode post penetrating the cover plate body along the first direction and connected to the positive electrode riveting block;

[0019] The positive electrode post, the positive electrode riveting block, and the negative electrode riveting block are all made of aluminum.

[0020] In some embodiments, the battery cover further includes a cover insulating member that covers the side of the battery cover opposite to the negative electrode riveting block.

[0021] A portion of the cover plate insulation extends between the plate structure and the cover plate body.

[0022] In some embodiments, the negative electrode assembly further includes:

[0023] A negative electrode insulating component is disposed between the negative electrode riveting block and the cover plate body;

[0024] A negative electrode sealing ring is sleeved on the outside of the column structure, and the two ends of the negative electrode sealing ring in the first direction are respectively connected to the negative electrode insulating component and the cover plate insulating component. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 is an isometric structural diagram of the copper-aluminum composite pole provided in an embodiment of this application;

[0027] Figure 2 is a cross-sectional view of the copper-aluminum composite pole provided in an embodiment of this application;

[0028] Figure 3 is an isometric structural diagram of the battery cover provided in an embodiment of this application;

[0029] Figure 4 is a front view of the battery cover provided in an embodiment of this application;

[0030] Figure 5 is a schematic diagram of the cross-sectional structure obtained by cutting the copper-aluminum composite pole provided in Figure 4 along the AA direction.

[0031] Figure 6 is an enlarged structural schematic diagram of the copper-aluminum composite pole at point B provided in Figure 5;

[0032] Figure 7 is a schematic diagram of the isometric structure of the battery cover plate according to another embodiment of this application;

[0033] Figure 8 is a cross-sectional structural diagram of a battery cover plate provided in another embodiment of this application;

[0034] Figure 9 is an isometric structural diagram of a copper-aluminum composite pole provided in another embodiment of this application;

[0035] Figure 10 shows the curve of IMC layer thickness as a function of annealing temperature.

[0036] Figure label:

[0037] 1-Negative electrode post assembly; 11-Copper-aluminum composite electrode post; 111-Column structure; 1111-First part; 1112-Second part; 112-Plate structure; 12-Negative electrode riveting block; 13-Negative electrode insulating component; 14-Negative electrode sealing ring; 2-Positive electrode post assembly; 21-Positive electrode post; 211-Column part; 212-Plate part; 22-Positive electrode riveting block; 23-Positive electrode insulating component; 24-Positive electrode sealing ring; 3-Cover plate body; 31-Cover plate insulating component; 4-Explosion-proof valve; 5-Injection hole.

[0038] F1 - First direction; F2 - Second direction; F3 - Third direction. Embodiments of the present invention

[0039] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0040] In the description of this application, it should be understood that the terms "upper," "lower," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. In the description of this application, "multiple" means two or more, and "at least one" can refer to one, two, or more, unless otherwise explicitly specified. The terms "first," "second," and "third," etc., are only for the convenience of description and are used to name parts or embodiments by number, and do not imply any order of importance between the parts or embodiments.

[0041] In the description of this application, "perpendicular" means completely perpendicular to 90° or almost completely perpendicular, for example, the range of included angles between 80° and 100° is considered perpendicular. Similarly, "parallel" means completely parallel or almost completely parallel, for example, the range of completely parallel angles between 10° is considered parallel.

[0042] The copper-aluminum composite electrode post 11 and battery cover plate according to some embodiments of this application are described below with reference to Figures 1 to 6.

[0043] Referring to Figures 1 to 6, an embodiment of the first aspect of this application provides a copper-aluminum composite electrode post 11. The copper-aluminum composite electrode post 11 includes a copper layer and an aluminum layer. The copper-aluminum composite electrode post 11 includes a column structure 111 and a plate structure 112. The plate structure 112 is integrally connected to one end of the column structure 111 in a first direction F1. Specifically, the first portion 1111 of both the plate structure 112 and the column structure 111 is a copper layer, located at the end of the column structure 111 near the plate structure 112. The second portion 1112 of the column structure 111 is an aluminum layer. The dimension of the first portion 1111 in the first direction F1 (i.e., the h value shown in Figure 2) is greater than or equal to 0.2 mm.

[0044] With all other structural dimensions being the same, the applicant selected copper-aluminum composite poles 11 with different dimensional data in the first direction F1 of the first part 1111, and conducted pull-out tests and lateral push-out tests on the copper-aluminum composite poles 11 respectively. Table 1 shows the dimensional data and corresponding test results of the pull-out tests and lateral push-out tests of the copper-aluminum composite poles 11.

[0045] It should be noted that the pull-out test of the copper-aluminum composite electrode 11 described above can be understood as using a tensile testing machine (e.g., a universal tensile testing machine) to apply force to both ends of the copper-aluminum composite electrode 11 in the first direction F1, pulling the copper-aluminum composite electrode 11 along the first direction F1, and recording the tensile force value at which the copper-aluminum composite electrode 11 breaks (i.e., the pull-out strength values ​​of the copper-aluminum composite electrode 11 shown in Table 1). The tensile strength of the copper-aluminum composite electrode 11 is considered acceptable if it is between 75 MPa and 95 MPa. The location of the breakage of the copper-aluminum composite electrode 11 is also observed.

[0046] Furthermore, the lateral thrust test of the copper-aluminum composite pole 11 can be understood as applying lateral thrusts perpendicular to the first direction F1 and of opposite directions and equal in magnitude to both ends of the copper-aluminum composite pole 11 in the first direction F1, in order to observe the fracture location of the copper-aluminum composite pole 11 under shear stress.

[0047] Table 1:

[0048]

[0049] As shown in Table 1, when the outer diameter d of the column structure 111 is the same, and the dimension h of the first part 1111 in the first direction F1 is less than 0.2 mm, regardless of whether d=5 mm, d=8 mm, d=12 mm or d=15 mm, the fracture location of the pull-out test and the side push test is the copper-aluminum joint surface. When the dimension h of the first part 1111 in the first direction F1 is greater than or equal to 0.2 mm, regardless of whether d=5 mm, d=8 mm, d=12 mm or d=15 mm, the fracture location in the pull-out test and the side push test is not at the copper-aluminum bonding surface. In other words, when the copper layer in the copper-aluminum composite pole 11 extends from the plate structure 112 to the pole structure 111, and the extension length of the copper layer on the pole structure 111, that is, the dimension of the first part 1111 in the first direction F1 (i.e., the h value shown in Figure 2) is greater than or equal to 0.2 mm, the copper layer and the aluminum layer of the copper-aluminum composite pole 11 are stably bonded, which can ensure that the copper-aluminum composite pole 11 maintains structural stability under vibration and bump conditions.

[0050] Preferably, in the first direction F1, the dimension h of the first part 1111 in the first direction F1 is less than or equal to 0.7 mm, as shown in Table 1. On the one hand, when 0.2 mm ≤ h of the copper-aluminum composite electrode 11, both the copper layer and the aluminum layer of the copper-aluminum composite electrode 11 can be stably bonded. On the other hand, making h ≤ 0.7 mm of the copper-aluminum composite electrode 11 can effectively balance the manufacturing cost of the copper-aluminum composite electrode 11.

[0051] As shown in Figures 1 to 6, F1 shown in the figures can be an example of the first direction F1 described above. For ease of description, two directions perpendicular to each other on a plane perpendicular to the first direction F1 are defined as the second direction F2 and the third direction F3. F2 shown in the figures can be an example of the second direction F2 described above, and F3 shown in the figures can be an example of the third direction F3 described above.

[0052] Preferably, as shown in FIG1, the above-mentioned column structure 111 can be a cylinder to facilitate the processing and manufacturing of the column structure 111.

[0053] Preferably, the outer diameter of the column structure 111 (i.e., the d value shown in Figure 2) can be greater than or equal to 5 mm. Referring to Table 2, when the outer diameter d of the column structure 111 is less than 5 mm, regardless of whether the h value is greater than 0.2 mm or greater than 0.7 mm, the tensile strength of the copper-aluminum composite pole 11 is unqualified, and the bonding stability between the copper layer and the aluminum layer is poor.

[0054] Table 2:

[0055]

[0056] Preferably, the outer diameter of the column structure 111 (i.e., the d value shown in FIG2) can be less than or equal to 15 mm to accommodate most battery cover structures.

[0057] Optionally, the copper-aluminum composite pole 11 can be a copper-aluminum friction welded component.

[0058] Optionally, the copper-aluminum composite pole 11 can be a copper-aluminum roll-formed composite.

[0059] Preferably, the operating temperature of the copper-aluminum composite electrode 11 can be less than or equal to 350°C. Thus, referring to Figure 10, which shows the curve of the IMC (i.e., intermetallic compound) layer thickness as a function of annealing temperature, when the operating temperature of the copper-aluminum composite electrode 11 can be less than or equal to 350°C, the thickness of the IMC generated by the phase transformation at the copper-aluminum interface under high temperature can be effectively reduced, thereby avoiding the impact of IMC on the bonding stability of the copper layer and the aluminum layer.

[0060] It should be noted that the above-mentioned column structure is not limited to the cylindrical structure shown in Figure 1. As long as the connection strength between the copper layer and the aluminum layer can be guaranteed, the above-mentioned column structure can also be other column structures, such as the elliptical column structure shown in Figure 9, or other polygonal columns, irregular columns, etc.

[0061] Referring to Figures 3 to 6, an embodiment of the second aspect of this application also provides a battery cover, including a cover body 3 and a negative terminal assembly 1. The negative terminal assembly 1 includes a negative terminal riveting block 12 and a copper-aluminum composite terminal 11 as described in any of the above embodiments, and thus has all the beneficial technical effects of the copper-aluminum composite terminal 11, which will not be repeated here.

[0062] Specifically, as shown in Figures 3 to 6, the column structure 111 of the copper-aluminum composite pole 11 penetrates the cover plate body 3 along the first direction F1 and is connected to the negative pole riveting block 12.

[0063] Preferably, as shown in Figures 3 to 6, the battery cover may further include a cover insulating member 31, which covers the side of the battery cover opposite to the negative electrode riveting block 12 to achieve insulation between the cover body and the battery interior. Preferably, as shown in Figure 6, a portion of the cover insulating member 31 extends between the plate structure 112 and the cover body 3 to facilitate insulation between the plate structure 112 and the cover body 3.

[0064] Preferably, as shown in Figures 3 to 6, the above-mentioned negative electrode post assembly 1 may further include a negative electrode insulating member 13, which may be disposed between the negative electrode riveting block 12 and the cover plate body 3 to achieve insulation between the negative electrode riveting block and the cover plate body 3.

[0065] Preferably, as shown in Figures 3 to 6, the negative electrode post assembly 1 may further include a negative electrode sealing ring 14, which can be sleeved on the outside of the post structure 111 to prevent the portion of the post structure 111 penetrating the cover plate body 3 from contacting the cover plate body 3. Furthermore, both ends of the negative electrode sealing ring 14 in the first direction F1 are connected to both the negative electrode insulating member 13 and the cover plate insulating member 31, so that the negative electrode post assembly 1 can be completely insulated from the cover plate body 3.

[0066] Optionally, the aforementioned negative electrode riveting block 12 can be riveted and fixed to the cover plate body 3 via multiple copper-aluminum composite poles 11 to improve the riveting stability and flatness of the negative electrode riveting block 12. As shown in Figures 7 and 8, an example is shown where the negative electrode riveting block 12 is riveted and fixed to the cover plate body 3 via two copper-aluminum composite poles 11. However, this is not the only possibility; the number of copper-aluminum composite poles 11 can be adjusted adaptively according to the size of the negative electrode riveting block 12.

[0067] Optionally, as shown in Figures 7 and 8, the figures illustrate an example where the battery cover includes only the negative terminal assembly. In other words, not shown in the figures, the battery cover can be applied to batteries where the negative and positive terminal assemblies are respectively located at both ends of the battery in a first direction, such as blade batteries.

[0068] However, this is not the only option. As shown in Figures 3 to 5, the battery cover may also include a positive terminal assembly 2. Correspondingly, as shown in Figure 5, the positive terminal assembly 2 may also include a positive terminal 21 and a positive terminal riveting block 22. A portion of the positive terminal 21 penetrates the cover body 3 along the first direction F1 and is connected to the positive terminal riveting block 22.

[0069] Similarly, as shown in Figure 5, the positive electrode post 21 may also include a plate portion 212 and a post portion 211 that are fixedly connected to each other. The post portion 211 passes through the cover plate body 3 along the first direction F1 and is connected to the positive electrode riveting block 22. The plate portion 212 is engaged on the side of the cover plate body 3 away from the positive electrode riveting block 22.

[0070] Correspondingly, as shown in FIG5, a portion of the cover plate insulating member 31 may also extend between the plate portion 212 and the cover plate body 3 to facilitate insulation between the plate portion 212 and the cover plate body 3.

[0071] Similarly, as shown in Figure 5, the positive electrode post assembly 2 may also include a positive electrode insulator 23 and a positive electrode sealing ring 24. The positive electrode insulator 23 can be disposed between the positive electrode riveting block 22 and the cover plate body 3 to achieve insulation between the positive electrode riveting block and the cover plate body 3. The positive electrode sealing ring 24 can be sleeved on the outside of the post portion 211 to prevent the portion of the post portion 211 penetrating the cover plate body 3 from contacting the cover plate body 3. Furthermore, both ends of the positive electrode sealing ring 24 in the first direction F1 are connected to both the positive electrode insulator 23 and the cover plate insulator 31, respectively, so that the positive electrode post assembly 2 can be completely insulated from the cover plate body 3.

[0072] Preferably, the positive electrode post 21, the positive electrode riveting block 22, and the negative electrode riveting block 12 are all aluminum parts.

[0073] Optionally, as shown in Figures 3 to 5, the positive terminal assembly 2 and the negative terminal assembly 1 are spaced apart along the second direction F2 to prevent the electrical connection of the positive terminal assembly 2 and the negative terminal assembly 1 from interfering with each other.

[0074] Preferably, as shown in Figures 3 to 5, the battery cover may further include an explosion-proof valve 4 to ensure battery safety. The explosion-proof valve 4 may be located in the portion of the cover body 3 between the positive terminal assembly 2 and the negative terminal assembly 1, thereby utilizing the space between the positive terminal assembly 2 and the negative terminal assembly 1 and improving the space utilization rate of the battery cover.

[0075] Preferably, as shown in Figures 3 to 5, the battery cover may further include an injection hole 5 to facilitate battery injection. The injection hole 5 may also be located in the portion of the cover body 3 between the positive terminal assembly 2 and the negative terminal assembly 1, so as to utilize the space between the positive terminal assembly 2 and the negative terminal assembly 1 of the cover body 3 and improve the space utilization rate of the battery cover.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. Industrial applicability

[0077] The copper-aluminum composite pole provided in this application extends the copper layer from the plate structure to the column structure, and the extension length of the copper layer on the column structure, that is, the dimension of the first part in the first direction is greater than or equal to 0.2mm. The copper layer and the aluminum layer of the copper-aluminum composite pole are stably combined, which can ensure that the copper-aluminum composite pole maintains structural stability under vibration and bump conditions.

Claims

1. A copper-aluminum composite terminal post, characterized by, The copper-aluminum composite electrode includes a copper layer and an aluminum layer. The copper-aluminum composite electrode includes a column structure and a plate structure. The plate structure is integrally connected to one end of the column structure in a first direction. Wherein, the first part of both the plate structure and the column structure is the copper layer, the first part is disposed at one end of the column structure near the plate structure, and the second part of the column structure is the aluminum layer; The dimension of the first part in the first direction is greater than or equal to 0.2 mm.

2. The copper-aluminum composite stud of claim 1, wherein In the first direction, the dimension of the first portion in the first direction is less than or equal to 0.7 mm.

3. The copper-aluminum composite stud of claim 2, wherein, The column structure is a cylinder, and the outer diameter of the column structure is greater than or equal to 5mm.

4. The copper-aluminum composite stud of claim 3, wherein, The outer diameter of the column structure is less than or equal to 15 mm.

5. The copper-aluminum composite stud of claim 1, wherein The copper-aluminum composite pole is a copper-aluminum friction welded part or a copper-aluminum roll-pressed composite part.

6. The copper-aluminum composite stud of claim 1, wherein, The copper-aluminum composite electrode is used at a temperature of less than or equal to 350°C.

7. A battery cover plate characterized by, It includes a cover plate body and a negative electrode post assembly, wherein the negative electrode post assembly includes a negative electrode riveting block and a copper-aluminum composite electrode post as described in any one of claims 1 to 6. The column structure of the copper-aluminum composite electrode extends through the cover plate body along the first direction and is connected to the negative electrode riveting block.

8. The battery cover plate of claim 7, wherein, It also includes a positive electrode post assembly, which includes a positive electrode post and a positive electrode riveting block. A portion of the positive electrode post penetrates the cover plate body along the first direction and is connected to the positive electrode riveting block. The positive electrode post, the positive electrode riveting block, and the negative electrode riveting block are all made of aluminum.

9. The battery cover according to claim 7, characterized in that, The battery cover also includes a cover insulating component, which covers the side of the battery cover opposite to the negative electrode riveting block. A portion of the cover plate insulation extends between the plate structure and the cover plate body.

10. The battery cover according to claim 9, characterized in that, The negative electrode assembly also includes: A negative electrode insulating component is disposed between the negative electrode riveting block and the cover plate body; A negative electrode sealing ring is sleeved on the outside of the column structure, and the two ends of the negative electrode sealing ring in the first direction are respectively connected to the negative electrode insulating component and the cover plate insulating component.

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