Composite pole, battery cover plate and battery

Abstract

The invention relates to the technical field of batteries, and particularly discloses a composite pole, a battery cover plate and a battery, the composite pole comprises a copper part and an aluminum part, the first end face of the copper part is provided with a flange, the inner wall face of the flange and the first end face of the copper part enclose a containing groove, and the end face of one end, located in the containing groove, of the aluminum part is a second end face. The second end face and the first end face form a copper-aluminum combination face through friction welding. A cylindrical first cutting layer is arranged in the circumferential direction of the aluminum part, and the circumferential side face of the first cutting layer and the inner wall face of the turned-over edge are arranged in a spaced mode. The outer diameter phi F of the first cutting layer and the inner diameter phi E of the first cutting layer meet the condition that phi F / phi E is larger than or equal to 1.25 and smaller than or equal to 3. Therefore, when the integrated structure formed by friction welding of the copper material part and the aluminum material part is machined, a material layer with relatively low connection strength on the circumferential outer ring of the copper-aluminum bonding surface can be removed, so that relatively high connection strength of the copper-aluminum bonding surface in the finished composite pole column is ensured. The invention also provides a battery cover plate and a battery. The battery cover plate comprises the composite pole.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a composite terminal post, a battery cover plate and a battery. Background Art

[0002] As a component in a lithium-ion battery, the main function of the battery cover plate is to isolate the internal and external environments through welding with the aluminum shell to play a sealing role. Secondly, it connects the internal and external circuits, and conveys the current inside the lithium-ion battery to the outside through the terminal post on the top cover, playing a current guiding role.

[0003] The terminal posts on traditional battery cover plates are generally fixed on the top cover by riveting. The terminal posts include a positive terminal post and a negative terminal post. In order to improve the performance of lithium-ion batteries, the negative terminal post is often a composite terminal post made of a copper-aluminum composite material, so as to reduce the internal resistance of the battery and improve the power and energy density of the battery. However, due to the low connection strength at the joint surface between the copper material and the aluminum material of the composite terminal post, the composite terminal post is prone to fall off after being assembled with the top cover, resulting in the failure of the terminal post. Summary of the Invention

[0004] The purpose of the present invention is to provide a composite terminal post, a battery cover plate and a battery, which define the important parameters for the friction welding forming of the composite terminal post, thereby improving the connection strength between the copper material part and the aluminum material part, avoiding the separation at the copper-aluminum joint surface of the composite terminal post, and having high reliability and safety.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] In a first aspect, the present invention provides a composite terminal post, including:

[0007] A copper material part, on the first end face of the copper material part, there is a flanging, and an inner wall surface of the flanging and the first end face form a receiving groove;

[0008] An aluminum material part, one end of the aluminum material part is located in the receiving groove, a second end face of the aluminum material part facing the copper material part is friction welded with the first end face to form a copper-aluminum joint surface, and a cylindrical first cutting layer is provided on the circumferential direction of the aluminum material part, and a circumferential side surface of the first cutting layer is spaced from the inner wall surface of the flanging;

[0009] Wherein, an outer diameter of the first cutting layer is φF, an inner diameter of the first cutting layer is φE, and φF and φE satisfy: 1.25 ≤ φF / φE ≤ 3;

[0010] The value range of φF is: 5mm ≤ φF ≤ 70mm;

[0011] The value range of φE is: 4mm ≤ φE ≤ Φ50mm.

[0012] Optionally, the thickness of the turned edge in the first direction is A, and the height of the turned edge in the second direction is B. The relationship between A and B satisfies: 1.5 ≤ B / A ≤ 3, and the relationship between A and φF satisfies: 0.1 ≤ A / φF ≤ 1;

[0013] The value range of A is: 2mm ≤ A ≤ 10mm;

[0014] The value range of B is: 3mm ≤ B ≤ 30mm.

[0015] Optionally, a second cutting layer is further provided on the circumferential direction of the aluminum material part. After the first cutting layer and the second cutting layer are peeled off from the aluminum material part, the remaining part of the aluminum material part includes a first cylinder and a second cylinder, and the end surface on the side of the second cylinder facing away from the first cylinder is the second end surface;

[0016] A third cutting layer is provided on the circumferential direction of the copper material part. After the third cutting layer is peeled off from the copper material part, the remaining part of the copper material part includes a plate body and a third cylinder, and the end surface on the side of the third cylinder facing away from the plate body is the first end surface.

[0017] Optionally, the copper-aluminum joint surface is an arc surface, and the copper-aluminum joint surface bulges toward the side where the plate body is located in the second direction. An annular intersection line is formed at the intersection of the copper-aluminum joint surface and the circumferential side surfaces of the second cylinder and the third cylinder;

[0018] In the second direction, the distance between the annular intersection line and the end surface on the side of the plate body facing the third cylinder is k, and the value range of k is: 0.2mm ≤ k ≤ 10mm.

[0019] Optionally, in the second direction, the height difference between the vertex of the copper-aluminum joint surface bulging toward the side where the plate body is located and the annular intersection line is a, and the value range of a is: 0.2mm ≤ a ≤ 0.5mm.

[0020] Optionally, in the second direction, the distance between the vertex of the copper-aluminum joint surface bulging toward the side where the plate body is located and the end surface on the side of the plate body facing away from the third cylinder is h;

[0021] The value range of h is: 1.5mm ≤ h ≤ 10mm.

[0022] Optionally, the roughness of the first end surface is γ1, and the value range of γ1 is:

[0023] Ra3.2 ≤ γ1 ≤ Ra12.5;

[0024] The roughness of the second end surface is γ2, and the value range of γ2 is: Ra3.2 ≤ γ2 ≤ Ra12.5.

[0025] Optionally, when the second end face of the aluminum part and the first end face of the copper part are friction welded, the bonding pressure is P, and the value range of P is: 100 Mpa ≤ P ≤ 200 Mpa.

[0026] In a second aspect, the present invention provides a battery cover plate, including a cover plate body and the composite pole column in any of the above solutions, and the composite pole column is integrated on the cover plate body.

[0027] In a third aspect, the present invention provides a battery, including the above battery cover plate.

[0028] The beneficial effects of the present invention are as follows:

[0029] The present invention provides a composite pole column, including a copper part and an aluminum part. A flanging is provided on the first end face of the copper part, and an accommodation groove is formed by the inner wall surface of the flanging and the first end face of the copper part. The end face of the aluminum part at one end located in the accommodation groove is the second end face, and the second end face and the first end face form a copper-aluminum bonding surface through friction welding, so that the copper part and the aluminum part are connected into an integral structure. The aluminum part is columnar, and a first cutting layer in the shape of a cylinder is provided on the circumference of the aluminum part, and the circumferential side surface of the first cutting layer is spaced from the inner wall surface of the flanging. The outer diameter φF and the inner diameter φE of the first cutting layer satisfy: 1.25 ≤ φF / φE ≤ 3. Thus, when machining the integral structure formed by friction welding of the copper part and the aluminum part, it is possible to remove the material layer with relatively low connection strength on the outer circumference of the copper-aluminum bonding surface to ensure that the connection strength between the copper part and the aluminum part in the finished composite pole column is relatively high. At the same time, the consumables are minimized and the cost is relatively low.

[0030] The present invention also provides a battery cover plate, including a cover plate body and the above composite pole column, and the composite pole column is integrated on the cover plate body. By adopting this composite pole column, after the composite pole column and the cover plate body are assembled, when the cover plate body is impacted, the composite pole column is not likely to separate at the copper-aluminum bonding surface, ensuring high reliability of the battery cover plate and not likely to fail.

[0031] The present invention also provides a battery, including the above battery cover plate. By adopting the above battery cover plate, the reliability of the battery can be ensured, and the battery cover plate is not likely to fail. Description of the Drawings

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for description in the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0033] Figure 1It is the top view of the composite pole column (before cutting) provided in the embodiment of the present invention;

[0034] Figure 2 is Figure 1 the sectional view of the I-I section in;

[0035] Figure 3 It is the sectional view of the composite pole column (after cutting) provided in the embodiment of the present invention;

[0036] Figure 4 It is the sectional view of the composite pole column (after cutting and riveting) provided in the embodiment of the present invention;

[0037] Figure 5 It is the exploded view of the battery cover plate provided in the embodiment of the present invention.

[0038] In the figure:

[0039] 100, composite pole column; 110, copper part; 111, flanging; 1101, accommodating groove; 112, third cutting layer; 113, third column body; 114, plate body; 120, aluminum part; 121, first cutting layer; 122, second cutting layer; 123, first column body; 1231, convex part; 124, second column body; 130, copper-aluminum joint surface; 200, cover plate body; 201, first mounting hole; 300, first plastic part; 301, second mounting hole; 400, second plastic part; 401, third mounting hole; 500, connecting block; 501, fourth mounting hole; 600, seal; 700, positive pole column. Detailed implementation manners

[0040] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and illustrated in the accompanying drawings here can be arranged and designed in various different configurations.

[0041] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed present invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0042] It should be noted that: similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0043] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the inventive product is usually placed during use. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", "third", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance. In the description of the present invention, unless otherwise specified, the meaning of "a plurality" is two or more.

[0044] In the description of the present invention, it should also be noted that unless otherwise clearly specified and defined, the terms "arranged" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the first and second features being in direct contact, or may include the first and second features not being in direct contact but being in contact through additional features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes the first feature being directly above and obliquely above the second feature, or merely indicating that the first feature has a higher horizontal height than the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes the first feature being directly below and obliquely below the second feature, or merely indicating that the first feature has a lower horizontal height than the second feature.

[0046] The embodiments of the present invention will be described in detail below. The examples of the embodiments are shown in the drawings, where the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as a limitation to the present invention.

[0047] As Figure 1 and Figure 2 shown, this embodiment provides a composite terminal post 100, which includes a copper part 110 and an aluminum part 120. The copper part 110 and the aluminum part 120 are connected by friction welding and form an integral structure. In order to facilitate the material flow and diffusion during friction welding, the aluminum part 120 can be selected as AL1060 H112, and the copper part 110 can be selected as CUTP2.

[0048] Specifically, a flanging 111 is provided on the first end face of the copper material part 110. The inner wall surface of the flanging 111 and the first end face of the copper material part 110 enclose a receiving groove 1101. The receiving groove 1101 is a groove with a circular cross-section. The aluminum material part 120 is columnar, and one end of the aluminum material part 120 is located in the receiving groove 1101. A cylindrical first cutting layer 121 is provided on the circumferential direction of the aluminum material part 120. The circumferential side surface of the first cutting layer 121 is spaced from the inner wall surface of the flanging 111. By providing a gap between the circumferential side surface of the first cutting layer 121 and the inner wall surface of the flanging 111, it is convenient to rotate the aluminum material part 120 so that the second end face of the aluminum material part 120 faces the first end face of the copper material part 110 and the first end face of the copper material part 110 generates a fusion connection under the high temperature generated by friction. Thus, the second end face and the first end face form a copper-aluminum joint surface 130 through friction welding, and the copper material part 110 and the aluminum material part 120 are connected into an integral structure.

[0049] It should be noted that when the copper material part 110 and the aluminum material part 120 are friction-welded, the aluminum of the aluminum material part 120 will flow outwards along the gap between the circumferential side surface of the first cutting layer 121 and the inner wall surface of the flanging 111, and the circumferential outer bonding strength of the copper-aluminum joint surface 130 between the copper material part 110 and the aluminum material part 120 is relatively low. Therefore, after the copper material part 110 and the aluminum material part 120 are formed into an integral structure by friction welding, the copper material part 110 and the aluminum material part 120 will be machined to remove the material layer on the circumferential outer circle of the copper-aluminum joint surface 130, and finally the finished composite pole column 100 is formed. In this embodiment, the first cutting layer 121 of the aluminum material part 120 will be removed, and at the same time, the area of the copper material part 110 connected to the first cutting layer 121 also needs to be cut off (the cut-off part is Figure 2 the dotted line part in). Thus, the part of the copper-aluminum joint surface 130 located on its circumferential outer circle will be cut off to ensure that the connection strength between the copper material part 110 and the aluminum material part 120 in the finished composite pole column 100 is relatively high.

[0050] Among them, the outer diameter of the first cutting layer 121 is φF, and the inner diameter of the first cutting layer 121 is φE. The relationship between φF and φE satisfies: 1.25 ≤ φF / φE ≤ 3. For example, the value of φF / φE can be 1.25, 1.50, 2.00, 2.50, 3.00, etc. By restricting the value of φF / φE within the above range, it can ensure that the part with relatively weak connection strength in the copper-aluminum joint surface 130 is removed, and the connection strength of the remaining copper-aluminum joint surface 130 is relatively high. At the same time, it saves material consumption and reduces costs. Otherwise, when the value of φF / φE is too small, the material layer removed from the outermost sides of the copper part 110 and the aluminum part 120 is relatively thin, affecting the connection strength of the copper-aluminum joint surface 130. When subjected to tensile force, the copper-aluminum joint surface 130 is likely to start to peel off from the periphery to the center, and the connection strength of the copper-aluminum joint surface 130 cannot be guaranteed to meet the requirements, resulting in a separation risk. When the value of φF / φE is too large, it causes more material consumption in the first cutting layer 121, resulting in a large amount of aluminum being wasted and the cost increasing.

[0051] It should be noted that the inner diameter φE of the first cutting layer 121 is the diameter after removing the material at the end where the aluminum part 120 is connected to the copper part 110, that is, the diameter of the copper-aluminum joint surface 130 in the finished composite pole 100. By restricting the value of φE within the above range, it can ensure that the mechanical strength of the aluminum part 120 itself is relatively high after removing the material, and it can resist a relatively large push-pull stress (>1000N) without breaking. At the same time, the bonding strength at the copper-aluminum joint surface 130 between the copper part 110 and the aluminum part 120 is also relatively high, and the copper part 110 and the aluminum part 120 are not easily separated, thus ensuring the stable assembly structure of the composite pole 100 on the cover body 200 and high reliability.

[0052] Optionally, in this embodiment, the value range of φE is: 4mm ≤ φE ≤ Φ50mm. For example, the value of φE can be 4mm, 10mm, 20mm, 30mm, 40mm, 50mm, etc.

[0053] The value range of φF is: 5mm ≤ φF ≤ 70mm. For example, when the value of φE is 4mm, the value of φF can be 5mm, 8mm, 10mm, or 12mm. When the value of φE is 20mm, the value of φF can be 25mm, 30mm, 40mm, 50mm, etc. When the value of φE is 50mm, the value of φF can be 62.5mm, 65mm, 70mm, etc.

[0054] Continue to refer to Figure 2 , in this embodiment, the thickness of the flanging 111 in the first direction is A, and the height of the flanging 111 in the second direction is B. Among them, the first direction is Figure 2 the Y-axis direction shown in Figure 2The Z-axis direction shown in the figure. The following relationships are satisfied between A and B: 1.5 ≤ B / A ≤ 3. For example, the value of B / A can be 1.50, 2.00, 2.50, 3.00, etc. And the following relationship is satisfied between A and φF: 0.1 ≤ A / φF ≤ 1. For example, the value of A / φF can be 0.1, 0.3, 0.5, 0.8, 1.0, etc. By restricting the values of B / A and A / φF within the above ranges, it can be ensured that the mechanical strength of the flanging 111 is relatively high. When the aluminum material part 120 is pressed to perform friction welding with the copper material part 110, the flanging 111 can inhibit the overflow of the aluminum material of the aluminum material part 120 outward from the gap between the circumferential side surface of the first cutting layer 121 and the inner wall surface of the flanging 111, reduce the loss of the aluminum material, and at the same time ensure that the bonding pressure between the aluminum material part 120 and the copper material part 110 meets the requirements, thereby ensuring that the connection strength of the copper-aluminum bonding surface 130 is relatively high and it is not easy to separate.

[0055] Optionally, the value range of A is: 2 mm ≤ A ≤ 10 mm. The value range of B is: 3 mm ≤ B ≤ 30 mm. For example, when the value of A is 2 mm, the value of B can be 3 mm, 4 mm, 5 mm, or 6 mm, and the value of φF can be 2 mm, 5 mm, 10 mm, 15 mm, 20 mm, etc. When the value of A is 10 mm, the value of B can be 15 mm, 20 mm, 25 mm, or 30 mm, and the value of φF can be 10 mm, 30 mm, 50 mm, or 70 mm, etc.

[0056] Furthermore, in order to ensure a relatively high connection strength of the friction welding between the copper material part 110 and the aluminum material part 120, in this embodiment, the roughness of the first end face is γ1, and the value range of γ1 is: Ra3.2 ≤ γ1 ≤ Ra12.5. The roughness of the second end face is γ2, and the value range of γ2 is: Ra3.2 ≤ γ2 ≤ Ra12.5. By restricting the roughness γ1 of the first end face and the roughness γ2 of the second end face within the range of Ra3.2 - Ra12.5, it can be ensured that the bonding strength during the friction welding of the first end face and the second end face is relatively high. Otherwise, when the values of γ1 and γ2 are too small, the roughness of the first end face and the second end face is small, and it is difficult for the copper material part 110 and the aluminum material part 120 to bond during friction welding. When the values of γ1 and γ2 are too large, the roughness of the first end face and the second end face is large, the temperature rise during the friction between the copper material part 110 and the aluminum material part 120 is too fast, and the metal grains at the copper-aluminum bonding surface 130 are quickly damaged, which will also affect the bonding strength between the copper material part 110 and the aluminum material part 120.

[0057] In addition, in order to avoid excessive temperature rise during the friction between the copper part 110 and the aluminum part 120, the rotational speed of the aluminum part 120 or the copper part 110 can be adjusted so that the temperature T of the contact surface between the copper part 110 and the aluminum part 120 during friction welding is between 400°C and 1000°C, that is, 400°C ≤ T ≤ 1000°C, to improve the bonding strength between the copper part 110 and the aluminum part 120.

[0058] Optionally, when the second end face of the aluminum part 120 is friction welded to the first end face of the copper part 110, the bonding pressure is P, and the value range of P is: 100 Mpa ≤ P ≤ 200 Mpa. For example, the value of P can be 100 Mpa, 150 Mpa, 200 Mpa, etc. By restricting the value of P within the above range, it is beneficial to improve the bonding strength between the copper part 110 and the aluminum part 120, and at the same time ensure that the deformation amounts of the copper part 110 and the aluminum part 120 are small, which is convenient for the subsequent machining process. Otherwise, when the value of P is too small, the connection strength between the copper part 110 and the aluminum part 120 at the copper-aluminum joint surface 130 is small; when the value of P is too large, it is easy to cause deformation of the copper part 110 or the aluminum part 120, which is not conducive to the subsequent machining process.

[0059] Continue to refer to Figure 2 and Figure 3 , after the copper part 110 and the aluminum part 120 are connected into an integral structure by friction welding, it is necessary to machine them to finally form the composite pole column 100. The specific parts that need to be removed during machining include the first cutting layer 121 and the second cutting layer 122 of the aluminum part 120, and the third cutting layer 112 of the copper part 110. Among them, the second cutting layer 122 of the aluminum part 120 is also located in the circumferential direction of the aluminum part 120, and the second cutting layer 122 is located inside the first cutting layer 121.

[0060] It should be noted that the first cutting layer 121 and the third cutting layer 112 can be carried out in one machining step, and then the second cutting layer 122 can be peeled off from the aluminum part 120 by machining. Finally, after the first cutting layer 121 and the second cutting layer 122 are peeled off from the aluminum part 120, the remaining part of the aluminum part 120 forms the first cylinder 123 and the second cylinder 124, and the diameter of the first cylinder 123 is smaller than the diameter of the second cylinder 124. The remaining part of the copper part 110 forms the plate body 114 and the third cylinder 113, and the third cylinder 113 is connected to the end of the second cylinder 124 facing away from the first cylinder 123. That is, the end face of the second cylinder 124 facing away from the first cylinder 123 is the second end face, the end face of the third cylinder 113 facing away from the plate body 114 is the first end face, and the end face of the second cylinder 124 facing away from the first cylinder 123 is combined with the end face of the third cylinder 113 facing away from the plate body 114 to form the copper-aluminum joint surface 130. After that, the composite pole column 100 is processed into a finished product and can be assembled with the cover body 200.

[0061] See Figure 4 and Figure 5 In some embodiments, after the first column 123 of the composite terminal post 100 passes through the cover plate body 200, it can be riveted to the connecting block 500 provided on one side of the cover plate body 200. The first column 123 bulges in its radial direction to form a convex portion 1231. Thus, the composite terminal post 100 can be fixed to the cover plate body 200 through the convex portion 1231 and the plate body 114.

[0062] Continue to refer to Figure 3 After the composite terminal post 100 in this embodiment is formed, its copper-aluminum bonding surface 130 is an arc surface, and the copper-aluminum bonding surface 130 bulges toward the side where the plate body 114 is located in the second direction. An annular intersection line is formed at the intersection of the copper-aluminum bonding surface 130 and the circumferential side surfaces of the second column 124 and the third column 113. In the second direction, the distance between the annular intersection line and the end surface of the plate body 114 facing the third column 113 is k, and the value range of k is: 0.2 mm ≤ k ≤ 10 mm. For example, the value of k can be 0.2 mm, 0.5 mm, 1.0 mm, 2.0 mm, 5.0 mm, 8.0 mm, 10.0 mm, etc. By adopting the above settings, the copper-aluminum bonding surface 130 is staggered from the position where the stress is most concentrated in the composite terminal post 100 (the connection between the plate body 114 and the third column 113), so as to have a certain protective effect on the copper-aluminum bonding surface 130 and reduce the risk of separation between the copper part 110 and the aluminum part 120.

[0063] In the second direction, the height difference between the vertex where the copper-aluminum bonding surface 130 bulges toward the side where the plate body 114 is located and the annular intersection line is a, and the value range of a is: 0.2 mm ≤ a ≤ 0.5 mm. For example, the value of a can be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, etc. By limiting the value of a within the above range, it can be ensured that the copper-aluminum bonding surface 130 does not bulge too much toward the side where the plate body 114 is located, and the connection strength between the copper part 110 and the aluminum part 120 can be improved as much as possible.

[0064] Furthermore, the plate body 114 of the composite terminal post 100 needs to be welded to the battery tab. In this embodiment, in the second direction, the distance between the vertex where the copper-aluminum bonding surface 130 bulges toward the side where the plate body 114 is located and the end surface of the plate body 114 facing away from the third column 113 is h, and the value range of h is: 1.5 mm ≤ h ≤ 10 mm. For example, the value of h can be 1.5 mm, 2.0 mm, 5.0 mm, 8.0 mm, 10.0 mm, etc. By limiting the value of h within the above range, the copper-aluminum bonding surface 130 is protected from the thermal influence generated during welding, so as to ensure that the bonding strength between the second column 124 and the third column 113 is relatively high and is not prone to separation.

[0065] The following uses the composite terminal post 100 in some specific embodiments to verify the parameter limitations in the above processing, and the results are shown in Table 1.

[0066] Table 1

[0067]

[0068] From the above results, it can be seen that in Embodiment 1, the value of the parameter φF / φE is close to the upper limit of its dimensional limit, the value of A / φF is at the lower limit of its dimensional limit, and the remaining parameters take normal values. At this time, the connection strength at the copper-aluminum joint surface 130 in the finished composite terminal post 100 is relatively high, it is not easy to separate, the reliability of the composite terminal post 100 is high, and the product is good.

[0069] In Embodiment 2, the value of the parameter φF / φE is at the lower limit of its dimensional limit, the value of A / φF is at the upper limit of its dimensional limit, and the remaining parameters take normal values. At this time, the connection strength at the copper-aluminum joint surface 130 in the finished composite terminal post 100 is relatively high, it is not easy to separate, the reliability of the composite terminal post 100 is high, and the product is good.

[0070] In Embodiment 3, the value of the parameter φF / φE is at the lower limit of its dimensional limit, the value of h is close to the lower limit of its dimensional limit, and the remaining parameters take normal values. At this time, the connection strength at the copper-aluminum joint surface 130 in the finished composite terminal post 100 is relatively high, it is not easy to separate, the reliability of the composite terminal post 100 is high, and the product is good.

[0071] In Embodiment 4, the value of the parameter B / A is at the upper limit of its dimensional limit, and the remaining parameters take normal values. At this time, the connection strength at the copper-aluminum joint surface 130 in the finished composite terminal post 100 is relatively high, it is not easy to separate, the reliability of the composite terminal post 100 is high, and the product is good.

[0072] In Embodiment 5, the value of the parameter B / A is at the lower limit of its dimensional limit, and the remaining parameters take normal values. At this time, the connection strength at the copper-aluminum joint surface 130 in the finished composite terminal post 100 is relatively high, it is not easy to separate, the reliability of the composite terminal post 100 is high, and the product is good.

[0073] In Embodiment 6, the value of the parameter a is close to the lower limit of its dimensional limit, and the remaining parameters take normal values. At this time, the connection strength at the copper-aluminum joint surface 130 in the finished composite terminal post 100 is relatively high, it is not easy to separate, the reliability of the composite terminal post 100 is high, and the product is good.

[0074] Referring to Comparative Example 1, the value of the parameter A / φF exceeds the lower limit of 0.1≤A / φF≤1, and the other parameters are all normal values. At this time, before the composite pole 100 is machined, when the copper material part 110 and the aluminum material part 120 are friction welded, the mechanical strength of the flange 111 of the copper material part 110 is insufficient, and the aluminum material part 120 has serious overflow. The pull-out force that the machined composite pole 100 can withstand is less than 1000N, and the composite pole 100 is easily separated at the copper-aluminum joint surface 130. The reliability of the composite pole 100 is low, and the product is defective.

[0075] Referring to Comparative Example 2, the value of the parameter φF / φE exceeds the lower limit of 1.25≤φF / φE≤3, and the other parameters are all normal values. At this time, the portion with low connection strength in the copper-aluminum joint surface 130 is not completely removed, resulting in the composite pole 100 being separated at the copper-aluminum joint surface 130 when the pull-out force that the machined composite pole 100 can withstand is less than 1000N, and the composite pole 100 is low in reliability and the product is defective.

[0076] Referring to Comparative Example 3, the value of parameter h exceeds the lower limit of 1.5 mm ≤ h ≤ 10 mm, and the other parameters are all normal values. At this time, the distance between the copper-aluminum joint surface 130 and the end surface of the plate body 114 away from the third column 113 is too close, and the copper-aluminum joint surface 130 is easily affected by the heat generated when the plate body 114 and the pole ear are welded, and the connection strength is reduced. The composite pole 100 is easy to separate at the copper-aluminum joint surface 130, the reliability is low, and the product is defective.

[0077] Referring to Comparative Example 4, the value of parameter A exceeds the lower limit of 2mm≤A≤10mm, and the other parameters are all normal values. At this time, before the composite pole 100 is machined, when the copper material part 110 and the aluminum material part 120 are friction welded, the mechanical strength of the flange 111 of the copper material part 110 is insufficient, and the aluminum material part 120 has serious overflow. When the pull-out force that the machined composite pole 100 can withstand is less than 1000N, the composite pole 100 separates at the copper-aluminum joint surface 130, and the reliability of the composite pole 100 is low, and the product is defective.

[0078] Referring to Comparative Example 5, the value of the parameter B / A exceeds the lower limit of 1.5≤B / A≤3, and the other parameters are all normal values. At this time, before the composite pole 100 is machined, when the copper material part 110 and the aluminum material part 120 are friction welded, the mechanical strength of the flange 111 of the copper material part 110 is insufficient, and the aluminum material part 120 has serious overflow. When the pull-out force that the machined composite pole 100 can withstand is less than 1000N, the composite pole 100 separates at the copper-aluminum joint surface 130, and the reliability of the composite pole 100 is low, and the product is defective.

[0079] Referring to Comparative Example 6, the value of parameter a exceeds the lower limit of 0.2 mm ≤ a ≤ 0.5 mm, and the other parameters are normal. At this time, the copper-aluminum joint surface 130 protrudes too much toward the side where the plate 114 is located, the connection strength at the copper-aluminum joint surface 130 decreases, and the composite pole 100 is easily separated at the copper-aluminum joint surface 130, resulting in low reliability and defective products.

[0080] In summary, the present invention defines the important parameters of the composite pole 100 during the friction welding forming and machining process. It can be seen that when the above parameters φE, φF, φF / φE, A, B / A, A / φF, a and h are within their corresponding size limits, the connection strength at the copper-aluminum bonding surface 130 of the machined composite pole 100 can be guaranteed to be high, and the pull-out force that can be withstood is greater than 1000N. The composite pole 100 is not easy to separate at the copper-aluminum bonding surface 130, and the reliability of the composite pole 100 is high.

[0081] See also Figure 5 The present embodiment further provides a battery cover, comprising a cover body 200 and the composite pole 100, wherein the composite pole 100 is integrated on the cover body 200. By adopting the composite pole 100 in the present embodiment, after the composite pole 100 is assembled with the cover body 200, when the cover body 200 is impacted, the composite pole 100 is not easy to separate at the copper-aluminum joint surface 130, and the composite pole 100 is well fixed on the cover body 200, thereby ensuring that the battery cover has high reliability and is not easy to fail.

[0082] Specifically, the battery cover in this embodiment further includes a first plastic part 300, a second plastic part 400 and a connecting block 500, wherein the first plastic part 300 and the second plastic part 400 are respectively arranged on both sides of the cover body 200, the connecting block 500 is arranged on the side of the first plastic part 300 away from the cover body 200, the cover body 200 is provided with a first mounting hole 201, the first plastic part 300 is provided with a second mounting hole 301, the second plastic part 400 is provided with a third mounting hole 401, and the connecting block 500 is provided with a first plastic part 300. The connecting block 500 is provided with a fourth mounting hole 501. After the first column 123 of the composite pole 100 passes through the third mounting hole 401, the first mounting hole 201, the second mounting hole 301 and the fourth mounting hole 501 in sequence, the first column 123 is riveted with the connecting block 500 to form a convex portion 1231. The convex portion 1231 is welded to the connecting block 500, and the plate 114 of the composite pole 100 is welded to the pole ear of the pole group, thereby realizing the installation of the composite pole 100 on the cover body 200. The battery cover also includes a sealing member 600, which is sleeved on the second column 124 and the third column 113 of the composite pole 100, and the sealing member 600 is sandwiched between the composite pole 100 and the cover body 200, and the sealing of the battery cover is realized by the sealing member 600.

[0083] Furthermore, the battery cover plate is also integrated with a positive electrode post 700, which is also integrated on the cover plate body 200. The installation structure of the positive electrode post 700 is the same as that of the composite electrode post 100.

[0084] This embodiment also provides a battery, which includes a housing, an electrode assembly, and the above-mentioned battery cover plate. The electrode assembly is disposed in the housing, and the battery cover plate seals the opening of the housing, and the electrode assembly is encapsulated by the battery cover plate and the housing. The electrode assembly includes a positive electrode tab and a negative electrode tab. The positive electrode tab is electrically connected to the positive electrode post 700, and the negative electrode tab is electrically connected to the plate body 114 of the composite electrode post 100. By adopting the above-mentioned battery cover plate, the reliability of the battery can be ensured to be relatively high, and the battery cover plate is not likely to fail.

[0085] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limiting the implementation manners of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A composite pole, characterized in that: The composite pole comprises: A copper material portion, wherein a first end surface of the copper material portion is provided with a flange, and an inner wall surface of the flange and the first end surface form a receiving groove; An aluminum part, one end of which is located in the receiving groove, a second end surface of the aluminum part facing the copper part is friction welded with the first end surface to form a copper-aluminum bonding surface, a first cylindrical cutting layer is provided in the circumference of the aluminum part, and a circumferential side surface of the first cutting layer is spaced apart from an inner wall surface of the flange; The outer diameter of the first cutting layer is φF, the inner diameter of the first cutting layer is φE, and φF and φE satisfy the following: 1.25≤φF / φE≤3; The value range of φF is: 5mm≤φF≤50mm; The value range of φE is: 4mm≤φE≤Φ50mm.

2. The composite pole according to claim 1, characterized in that: The thickness of the flange along the first direction is A, and the height of the flange along the second direction is B; A and B satisfy: 1.5≤B / A≤3; A and φF satisfy: 0.1≤A / φF≤1; The value range of A is: 2mm≤A≤10mm; The value range of B is: 3mm≤B≤30mm.

3. The composite pole according to claim 1, characterized in that: A second cutting layer is also provided in the circumference of the aluminum part. After the first cutting layer and the second cutting layer are peeled off from the aluminum part, the remaining part of the aluminum part includes a first column and a second column, and the end face of the second column facing away from the first column is the second end face; A third cutting layer is provided in the circumference of the copper material part. After the third cutting layer is peeled off from the copper material part, the remaining part of the copper material part includes a plate body and a third column body, and the end face of the third column body facing away from the plate body is the first end face.

4. The composite pole according to claim 3, characterized in that: The copper-aluminum bonding surface is an arc surface, and along the second direction, the copper-aluminum bonding surface is convex toward the side where the plate body is located, and the intersection of the copper-aluminum bonding surface and the peripheral side surfaces of the second column and the third column forms a ring-shaped intersection line; Along the second direction, the distance between the annular intersection line and the end surface of the plate body facing the third column is k, and the value range of k is: 0.2mm≤k≤10mm.

5. The composite pole according to claim 4, characterized in that: Along the second direction, the height difference between the vertex of the protrusion on the side where the copper-aluminum combination faces the plate body and the annular intersection line is a; The value range of a is: 0.2mm≤a≤0.5mm.

6. The composite pole according to claim 4, characterized in that: Along the second direction, the distance between the vertex of the protrusion on the side of the copper-aluminum combination surface facing the plate body and the end surface of the plate body away from the third column is h, and the value range of h is: 1.5mm≤h≤10mm.

7. The composite pole according to claim 1, characterized in that: The roughness of the first end surface is γ1, and the value range of γ1 is: Ra3.2≤γ1≤Ra12.5; The roughness of the second end surface is γ2, and the value range of γ2 is: Ra3.2≤γ2≤Ra12.

5.

8. The composite pole according to claim 1, characterized in that: The bonding pressure when the second end surface of the aluminum material part and the first end surface of the copper material part are friction welded is P; The value range of P is: 100Mpa≤P≤200Mpa.

9. A battery cover, characterized in that: It comprises a cover plate body and the composite pole according to any one of claims 1 to 8, wherein the composite pole is integrated on the cover plate body.

10. A battery, characterized in that: The invention comprises the battery cover plate as claimed in claim 9.

Images