Composite electrode assembly

Abstract

The utility model discloses a composite electrode assembly, which relates to the technical field of batteries and comprises a composite pole, a copper switching piece and an insulating spacer, the composite pole is composed of an aluminum pole and a copper connecting piece, and the copper connecting piece protrudes to form a welding part; a welding hole is formed in the copper adapter sheet, and the welding part is fixedly arranged in the welding hole through laser welding; the insulating spacer is attached to one surface of the copper switching sheet and covers the welding hole; the area of the copper switching piece is S0, the projection area of the aluminum pole is S1, the projection area of the copper connecting piece is S2, the projection area of the welding part is S3, the projection area of the welding hole is S4, the projection area of the insulating spacer is S5, and S1 < S3 < S4 < S2 < S5 < S0. According to the utility model, the projection of the welding seam can be prevented from falling in the copper-aluminum interface, the stability of the copper-aluminum interface is favorably guaranteed, the deformation risk is reduced, and the structural stability of the composite pole is favorably guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a composite electrode assembly. Background Art

[0002] In some power batteries, the positive electrode tab is made of aluminum foil and the negative electrode tab is made of copper foil. Therefore, in order to ensure the same materials during welding, a copper-aluminum composite structure is generally adopted at the negative electrode end, that is, a copper-aluminum composite pole column is used in combination with a copper adapter piece to ensure the same welding materials.

[0003] In the existing copper-aluminum composite structure, there is a copper-aluminum interface in the copper-aluminum composite pole column, and there is a weld between the copper-aluminum composite pole column and the copper adapter piece, and the projection of the weld falls within the copper-aluminum interface. When welding the copper-aluminum composite pole column and the copper adapter piece, since the projection of the weld falls within the copper-aluminum interface, the copper-aluminum interface is easily affected by the heat during welding and there is a risk of deformation; once the copper-aluminum interface is deformed, the structure of the copper-aluminum composite pole column will also become unstable, and it is easy to break or fail during use. Summary of the Utility Model

[0004] The purpose of the utility model is to overcome the deficiencies of the prior art. The utility model provides a composite electrode assembly. By restricting the projected areas of the aluminum pole column, copper connecting piece, welding part and welding hole on the copper adapter piece, the projection of the weld is prevented from falling within the copper-aluminum interface, which is beneficial to ensuring the stability of the copper-aluminum interface, reducing the risk of its deformation, and thus beneficial to ensuring the structural stability of the composite pole column.

[0005] The utility model provides a composite electrode assembly, which includes a composite pole column, a copper adapter piece and an insulating gasket. The composite pole column is composed of an aluminum pole column and a copper connecting piece, and the aluminum pole column and the copper connecting piece are fixedly connected. A welding part is formed in a protruding manner on the side of the copper connecting piece away from the aluminum pole column; a welding hole is formed in the copper adapter piece, and the welding part is fixedly arranged in the welding hole by laser welding; the insulating gasket is attached to the side of the copper adapter piece away from the aluminum pole column, and the insulating gasket covers the welding hole;

[0006] The area of the copper adapter piece is S 0 , the projected area of the aluminum pole column on the copper adapter piece is S 1 , the projected area of the copper connecting piece on the copper adapter piece is S 2 , the projected area of the welding part on the copper adapter piece is S 3 , the projected area of the welding hole on the copper adapter piece is S 4 , the projected area of the insulating gasket on the copper adapter piece is S 5 , the S 0, the said S 1 , the said S 2 , the said S 3 , the said S 4 and the said S 5 The constraint relationship of is: S 1 < S 3 < S 4 < S 2 < S 5 < S 0 .

[0007] Specifically, the radial direction of the aluminum pole column shrinks step by step away from the copper connecting piece, successively forming a first step portion, a second step portion and a third step portion.

[0008] Specifically, the height of the first step portion is H 1 , the height of the second step portion is H 2 , the height of the third step portion is H 3 , the H 1 , the said H 2 and the said H 3 The constraint relationship of is: H 2 < H 1 < H 3 .

[0009] Specifically, a first chamfer is formed at the convex edge of the second step portion.

[0010] Specifically, a connecting boss is convexly formed on the surface of the copper connecting piece that is in contact with the aluminum pole column. The aluminum pole column is fixedly arranged on the connecting boss, and the bottom contour of the aluminum pole column coincides with the contour of the connecting boss.

[0011] Specifically, a first welding groove is formed on the surface of the welding portion away from the copper connecting piece. The first welding groove is arranged along the circumferential direction of the welding portion; a second welding groove is formed on the surface of the copper adapter piece away from the aluminum pole column. The second welding groove is arranged along the circumferential direction of the welding hole; the first welding groove and the second welding groove are connected to form a welding channel.

[0012] Specifically, the width of the welding channel is greater than or equal to 4.0 mm.

[0013] Specifically, a first notch is formed on one side of the copper adapter piece, and pole ear welding areas are arranged on both sides of the first notch.

[0014] Specifically, a first positioning portion is arranged on the side of the copper adapter piece away from the first notch.

[0015] Specifically, the outer peripheral profiles of the aluminum pole column, the copper connecting piece, the welding part, and the welding hole are all waist-shaped structures.

[0016] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0017] In the composite electrode assembly of the present utility model, there is a copper-aluminum interface between the aluminum pole column and the copper connecting piece, and there is a weld between the welding part and the welding hole. By restricting the projected areas of the aluminum pole column, the copper connecting piece, the welding part, and the welding hole on the copper adapter plate, it is avoided that the projection of the weld falls within the copper-aluminum interface, which can effectively weaken the influence of the welding heat on the copper-aluminum interface, is beneficial to ensuring the stability of the copper-aluminum interface, reducing the risk of its deformation, and thus is beneficial to ensuring the structural stability of the composite pole column. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0019] Figure 1 is an exploded structural schematic diagram of the composite electrode assembly in the embodiment of the present utility model;

[0020] Figure 2 is a cross-sectional structural schematic diagram of the composite electrode assembly in the embodiment of the present utility model;

[0021] Figure 3 is Figure 2 a schematic diagram of the enlarged structure of area A in

[0022] Figure 4 is Figure 2 a schematic diagram of the enlarged structure of area B in

[0023] Figure 5 is Figure 2 a schematic diagram of the enlarged structure of area C in

[0024] In the drawings, 100, composite pole column; 110, aluminum pole column; 111, first stepped part; 112, second stepped part; 1121, first chamfer; 113, third stepped part; 120, copper connecting piece; 121, connecting boss; 130, welding part; 131, first welding groove; 200, copper adapter plate; 210, welding hole; 211, second welding groove; 220, first notch; 221, pole ear welding area; 230, first positioning part; 300, insulating gasket; 310, second notch; 320, second positioning part. Detailed implementation mode

[0025] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

[0026] Figure 1 The exploded structural schematic diagram of the composite electrode assembly in the embodiment of the present invention is shown. Figure 2 The cross-sectional structural schematic diagram of the composite electrode assembly in the embodiment of the present invention is shown. The composite electrode assembly includes a composite pole column 100, a copper adapter piece 200, and an insulating gasket 300. The composite pole column 100 is composed of an aluminum pole column 110 and a copper connecting piece 120. The aluminum pole column 110 and the copper connecting piece 120 are fixedly connected. A welding part 130 is formed in a protruding manner on the side of the copper connecting piece 120 away from the aluminum pole column 110. A welding hole 210 is formed in the copper adapter piece 200, and the welding part 130 is fixedly arranged in the welding hole 210 through laser welding. The insulating gasket 300 is attached to the side of the copper adapter piece 200 away from the aluminum pole column 110, and the insulating gasket 300 covers the welding hole 210.

[0027] The area of the copper adapter piece 200 is S 0 , the projected area of the aluminum pole column 110 on the copper adapter piece 200 is S 1 , the projected area of the copper connecting piece 120 on the copper adapter piece 200 is S 2 , the projected area of the welding part 130 on the copper adapter piece 200 is S 3 , the projected area of the welding hole 210 on the copper adapter piece 200 is S 4 , the projected area of the insulating gasket 300 on the copper adapter piece 200 is S 5 , the S 0 , the S 1 , the S 2 , the S 3 , the S 4 and the S 5 The constraint relationship is: S 1 < S 3 < S 4 < S 2 < S 5 < S 0 .

[0028] In the composite electrode assembly of the present utility model, there is a copper-aluminum interface between the aluminum pole column 110 and the copper connecting piece 120, and there is a weld seam between the welding part 130 and the welding hole 210. By restricting the projected areas of the aluminum pole column 110, the copper connecting piece 120, the welding part 130, and the welding hole 210 on the copper adapter plate 200, it is possible to avoid the projection of the weld seam falling within the copper-aluminum interface, effectively reducing the influence of the welding heat on the copper-aluminum interface, facilitating the guarantee of the stability of the copper-aluminum interface, reducing the risk of its deformation, and thus being conducive to ensuring the structural stability of the composite pole column 100.

[0029] Moreover, the copper connecting piece 120 and the welding part 130 cooperate to stably install the composite pole column 100 in the welding hole 210, making it not easy for the composite pole column 100 to skew during welding; the copper connecting piece 120 can shield one side of the weld seam to prevent welding slag from splashing out from this side during welding.

[0030] In addition, the insulating gasket 300 covers the other side of the weld seam. On the one hand, it can prevent dust, water vapor, etc. from entering the weld seam, and on the other hand, it can prevent particulate matter from falling into the battery cell from the weld seam; at the same time, the insulating gasket 300 can also prevent the copper adapter plate 200 from directly contacting the battery cell, effectively reducing the risk of short circuit.

[0031] In some specific embodiments, the geometric centers of the aluminum pole column 110, the copper connecting piece 120, the welding part 130, and the welding hole 210 are all located on the same vertical line, which is conducive to improving the assembly efficiency of the composite pole column 100 and the copper adapter plate 200, and the assembly accuracy is good.

[0032] In some specific embodiments, please refer to Figure 2 , the radial direction of the aluminum pole column 110 shrinks stepwise away from the copper connecting piece 120, successively forming a first stepped portion 111, a second stepped portion 112, and a third stepped portion 113, which is convenient for cooperating with the battery cover plate and has a large contact area with the battery cover plate, and can improve the installation stability of the aluminum pole column 110 in the battery cover plate.

[0033] Specifically, the height of the first stepped portion 111 is H 1 , the height of the second stepped portion 112 is H 2 , the height of the third stepped portion 113 is H 3 , the H 1 , the H 2 and the H 3 The constraint relationship is: H 2 <H 1 <H 3The first step needs to be connected to the copper connecting piece 120 and enough height should be reserved; the second step is mainly used to improve the installation stability of the aluminum pole 110 in the battery cover plate and does not need to be too high; the third step needs to pass through the battery cover plate and enough height is required.

[0034] Figure 3 shows Figure 2 a schematic enlarged view of the structure of area A in [reference], a first chamfer 1121 is formed at the convex edge of the second step portion 112, which can further increase the contact area between the aluminum pole 110 and the battery cover plate, thereby improving the installation stability of the aluminum pole 110 in the battery cover plate.

[0035] Figure 4 shows Figure 2 a schematic enlarged view of the structure of area B in [reference], a connecting boss 121 is convexly formed on the surface of the copper connecting piece 120 that is in contact with the aluminum pole 110, the aluminum pole 110 is fixedly arranged on the connecting boss 121, and the bottom contour of the aluminum pole 110 fits the contour of the connecting boss 121. The aluminum pole 110 being fixedly arranged on the connecting boss 121 is beneficial to ensuring the flatness of the copper-aluminum interface and reducing the internal stress at the copper-aluminum interface.

[0036] Specifically, the height of the connecting boss 121 is 0.1 mm, and the formed copper-aluminum interface has good flatness.

[0037] Figure 5 shows Figure 2 a schematic enlarged view of the structure of area C in [reference], a first welding groove 131 is formed on the surface of the welding part 130 away from the copper connecting piece 120, and the first welding groove 131 is arranged along the circumferential direction of the welding part 130; a second welding groove 211 is formed on the surface of the copper adapter 200 away from the aluminum pole 110, and the second welding groove 211 is arranged along the circumferential direction of the welding hole 210; the first welding groove 131 and the second welding groove 211 are connected to form a welding channel. The welding channel can provide a good accommodation space for the formation of the weld seam and can prevent the weld seam from being higher than the surface of the copper adapter 200.

[0038] Specifically, the width of the welding channel is greater than or equal to 4.0 mm, the width of the first welding groove 131 is greater than or equal to 2.0 mm, the width of the second welding groove 211 is greater than or equal to 2.0 mm, and the depth of the welding channel is 0.05 mm, leaving enough space for the formation of the weld seam.

[0039] Furthermore, the effective penetration depth of the weld seam is 0.7 mm, the penetration width is greater than or equal to 1.2 mm, and the welding strength is good; there is no false soldering or de-soldering; the weld seam is continuous and smooth, without welding holes, explosion points, protrusions, etc.

[0040] In some specific embodiments, please refer to Figure 1 , on one side of the copper adapter piece 200, a first notch 220 is formed, and tab welding areas 221 are arranged on both sides of the first notch 220. The first notch 220 is used to avoid certain structures and facilitate the installation of the composite electrode assembly; the tab welding areas 221 are used for ultrasonic welding of the negative tabs.

[0041] Please refer to Figure 1 , on the side of the copper adapter piece 200 away from the first notch 220, a first positioning portion 230 is provided, and the insulating gasket 300 is correspondingly provided with a second notch 310 and a second positioning portion 320, which facilitates accurately fitting the insulating gasket 300 onto the copper adapter piece 200. The insulating gasket 300 is smaller than the copper adapter piece 200 and is required to be closely fitted to the copper adapter piece 200 without air bubbles or warping, and the insulating gasket 300 shall not protrude beyond the edge of the copper adapter piece 200.

[0042] In some specific embodiments, the outer peripheral contour of the copper adapter piece 200 is rounded to form a first rounded portion, which can avoid cutting the tabs. Moreover, the surface of the copper adapter piece 200 is clean without defects such as oil stains, cleaning agent residues, oxidation, etc.; the burrs are ≤0.1 mm, and the size of the surface metal chips is ≤200 μm.

[0043] Specifically, the thickness range of the copper adapter piece 200 is 0.75 mm to 0.85 mm, adopting Cu T2-M state, with a hardness of ≤62°, having sufficient mechanical strength and good ultrasonic welding effect with the negative tabs.

[0044] In some specific embodiments, the insulating gasket 300 is a PET gasket with a back acrylic pressure-sensitive adhesive, having good insulation performance and good adhesion to the copper adapter piece 200. Specifically, the thickness range of the PET gasket is 0.32 mm to 0.38 mm, and the thickness range of the back adhesive is 0.04 mm to 0.06 mm.

[0045] In some specific embodiments, please refer to Figure 1 , the outer peripheral contours of the aluminum pole column 110, the copper connecting piece 120, the welding portion 130, and the welding hole 210 are all waist-shaped structures, having good installation stability, a large surface area, and facilitating the connection of the composite electrode assembly with other components.

[0046] Specifically, the major axis range of the aluminum pole column 110 is 41.45 mm to 41.55 mm, and the minor axis range of the aluminum pole column 110 is 15.45 mm to 15.55 mm; the major axis range of the copper connecting piece 120 is 49.95 mm to 50.05 mm, and the minor axis range of the copper connecting piece 120 is 23.95 mm to 24.05 mm; the major axis range of the welding part 130 is 46.85 mm to 46.95 mm, and the minor axis range of the welding part 130 is 20.85 mm to 20.95 mm; the major axis range of the welding hole 210 is 47.00 mm to 47.05 mm, and the minor axis range of the welding hole 210 is 21.00 mm to 21.05 mm. It is applicable to most power batteries.

[0047] Furthermore, the aluminum pole column 110 is made of Al 1060H18, and the copper connecting piece 120 is made of Cu T2, and the formed composite pole column 100 has good electrical performance.

[0048] For the composite electrode assembly of the present utility model, by restricting the projected areas of the aluminum pole column 110, the copper connecting piece 120, the welding part 130 and the welding hole 210 on the copper adapter piece 200, it is avoided that the projection of the weld seam falls within the copper-aluminum interface, which can effectively weaken the influence of the welding heat on the copper-aluminum interface, is beneficial to ensuring the stability of the copper-aluminum interface, reducing the risk of its deformation, and thus is beneficial to ensuring the structural stability of the composite pole column 100. The copper connecting piece 120 and the welding part 130 can stably install the composite pole column 100 in the welding hole 210, making the composite pole column 100 not easy to skew during welding; the copper connecting piece 120 can shield one side of the weld seam to prevent the welding slag from splashing out from this side during welding. The insulating gasket 300 covers the other side of the weld seam. On the one hand, it can prevent dust, water vapor, etc. from entering the weld seam, and on the other hand, it can prevent the weld seam from dropping particulate matter into the battery cell; the insulating gasket 300 can also prevent the copper adapter piece 200 from directly contacting the battery cell, effectively reducing the risk of short circuit.

[0049] Moreover, the aluminum pole column 110 forms a stepped structure, which is convenient for cooperating with the battery cover plate and has a large contact area with the battery cover plate, which can improve the installation stability of the aluminum pole column 110 in the battery cover plate; the aluminum pole column 110 is fixed on the copper connecting piece 120 based on the connecting boss 121, which is beneficial to ensuring the flatness of the copper-aluminum interface and reducing the internal stress of the copper-aluminum interface. A welding channel is formed between the welding part 130 and the copper adapter piece 200, which can provide a good accommodation space for the formation of the weld seam and can also prevent the weld seam from being higher than the surface of the copper adapter piece 200.

[0050] In addition, the aluminum pole 110, the copper connecting piece 120, the welding part 130 and the welding hole 210 are in a kidney-shaped structure, which has good installation stability, a large surface area, is applicable to most power batteries, and facilitates the connection of the composite electrode assembly with other components.

[0051] The above has introduced in detail a composite electrode assembly provided by an embodiment of the present invention. Specific examples are used herein to illustrate the principle and implementation manner of the present invention. The description of the above embodiments is only used to help understand the method and its core idea of the present invention; at the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present invention.

Claims

1. A composite electrode assembly, characterized in that: The composite electrode assembly comprises a composite pole, a copper adapter and an insulating gasket, wherein the composite pole is composed of an aluminum pole and a copper connecting piece, wherein the aluminum pole and the copper connecting piece are fixedly connected, and a welding portion is protruded on a side of the copper connecting piece away from the aluminum pole; a welding hole is provided in the copper adapter, and the welding portion is fixedly arranged in the welding hole by laser welding; the insulating gasket is attached to a side of the copper adapter away from the aluminum pole, and the insulating gasket covers the welding hole; The area of ​​the copper adapter is S0, the projected area of ​​the aluminum pole on the copper adapter is S1, the projected area of ​​the copper connecting plate on the copper adapter is S2, the projected area of ​​the welding part on the copper adapter is S3, the projected area of ​​the welding hole on the copper adapter is S4, and the projected area of ​​the insulating gasket on the copper adapter is S5. The constraint relationship among S0, S1, S2, S3, S4 and S5 is: S1<S3<S4<S2<S5<S0.

2. The composite electrode assembly according to claim 1, characterized in that The radial direction of the aluminum pole is stepped-contracted in a direction away from the copper connecting piece, forming a first step portion, a second step portion and a third step portion in sequence.

3. The composite electrode assembly according to claim 2, characterized in that: The height of the first step portion is H1, the height of the second step portion is H2, and the height of the third step portion is H3. The constraint relationship among H1, H2 and H3 is: H2<H1<H3.

4. The composite electrode assembly according to claim 2, characterized in that: A first chamfer is formed at the convex edge of the second step portion.

5. The composite electrode assembly according to claim 1, characterized in that: A connecting boss is protrudingly formed on one side of the copper connecting piece that is connected to the aluminum pole. The aluminum pole is fixedly arranged on the connecting boss. The bottom contour of the aluminum pole is consistent with the contour of the connecting boss.

6. The composite electrode assembly according to claim 1, characterized in that: A first welding groove is formed on a side of the welding portion away from the copper connecting plate, and the first welding groove is arranged along the circumference of the welding portion; a second welding groove is formed on a side of the copper adapter plate away from the aluminum pole, and the second welding groove is arranged along the circumference of the welding hole; the first welding groove and the second welding groove are connected to form a welding channel.

7. The composite electrode assembly according to claim 6, characterized in that The width of the welding channel is greater than or equal to 4.0 mm.

8. The composite electrode assembly according to claim 1, characterized in that: A first notch is formed on one side of the copper adapter plate, and tab welding areas are arranged on both sides of the first notch.

9. The composite electrode assembly according to claim 8, characterized in that A first positioning portion is disposed on a side of the copper adapter sheet away from the first notch.

10. The composite electrode assembly according to claim 1, characterized in that: The outer peripheral contour of the aluminum pole, the outer peripheral contour of the copper connecting piece, the outer peripheral contour of the welding portion and the welding hole are all waist-shaped structures.

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