Convergence piece and cylindrical battery

Abstract

The utility model discloses a confluence sheet, which comprises a circular confluence sheet body, the middle part of the confluence sheet body is provided with a central hole which is concentrically arranged, the confluence sheet is characterized in that the edge of the confluence sheet body is provided with a plurality of turnup edges which are turned over towards one side, and the turnup edges are uniformly distributed along the circumferential direction of the confluence sheet body; the junction of the bus bar body and the flange is drawn in the direction towards the flange to form a boss, and the flange is located on the edge of the boss. The utility model has the advantages of reasonable structural design, can avoid diaphragm fusion, is favorable for guaranteeing battery quality, and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a busbar and a cylindrical battery. Background Art

[0002] At present, with the rapid development of the new energy industry, society's requirements for the energy density, safety performance, and fast charging performance of lithium-ion batteries have been further improved. As a highly recognized solution, large cylindrical batteries have ushered in a broad market space. Large cylindrical batteries usually use two upper and lower busbars to connect the positive and negative electrodes of the core respectively. In order to reliably connect the busbars to the positive and negative electrodes, the busbars need to be pressed tightly on the core and laser welded. After the welding of the core is completed, the busbars need to be welded to the shell or pole. Usually, the busbars and the shell are penetrated and welded. During welding, the welding heat is easily transferred to the core through the busbars, causing the diaphragm near the welding position to melt, affecting the quality of the battery. Utility Model Content

[0003] In view of the above-mentioned deficiencies in the prior art, the technical problem to be solved by the present invention is: how to provide a busbar and a cylindrical battery with a reasonable structural design, which can avoid the melting of the diaphragm and help ensure the quality of the battery.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A busbar comprises a circular busbar body, the middle part of which has a concentrically arranged center hole, and is characterized in that the edge of the busbar body has a flange folded toward one side, and a plurality of flanges are evenly distributed along the circumference of the busbar body; the connection between the busbar body and the flange is drawn in the direction of the flange to form a boss, and the flange is located on the edge of the boss.

[0006] In the above structure, since the boss is formed by drawing the busbar body, a gap will be formed between the boss and the core after the busbar body is welded to the core. When the flange is welded to the shell, the temperature rises suddenly and the heat is conducted to the shell and the flange. Due to the existence of the gap, the heat cannot be directly conducted to the diaphragm, thereby avoiding the diaphragm from melting due to excessive temperature, which is beneficial to ensuring the quality of the battery.

[0007] Furthermore, the edge of the boss has a connecting portion extending radially outwardly along the busbar body, and the flange is connected to the edge of the connecting portion.

[0008] In this way, the flange can be kept away from the edge of the busbar body in the radial direction, and the welding position can be kept away from the winding core, thereby reducing the risk of the diaphragm melting.

[0009] Furthermore, the connecting portion has a through-going weakening hole, and a plurality of the weakening holes are arranged at intervals along the length direction of the connecting portion.

[0010] In this way, the strength of the connection part can be reduced and the flexibility of the connection part can be increased, so that the flange can better adapt to the inner wall of the shell, thereby making the flange and the shell in closer contact, preventing cold welding and helping to improve the reliability of welding.

[0011] Furthermore, the thickness of the connecting portion is smaller than the thickness of the busbar body.

[0012] In this way, when the outer side applies downward force to the busbar during the rolling groove sealing process, the thinner connecting portion on the boss can be bent, thereby reducing the force applied by the busbar to the pole group and preventing the pole group from being compressed and deformed.

[0013] Furthermore, the boss is extended radially toward the middle of the busbar body and is arranged in a fan shape.

[0014] Furthermore, the boss has a through hole extending therethrough.

[0015] Furthermore, at least two through holes are provided along the radial direction of the busbar body, and the diameters of the through holes gradually decrease in a direction away from the flange.

[0016] Furthermore, a radially extending groove is provided in the middle of the busbar body, and one end of the groove is connected to the center hole; a plurality of the grooves are evenly distributed along the circumference of the busbar body.

[0017] In this way, the middle part of the busbar body is divided into multiple petals by cutting grooves. When the busbar is welded to the shell, the busbar is subjected to the inward force of the shell, and the multiple petals can release part of the pressure.

[0018] Furthermore, a columnar protrusion is concentrically arranged in the middle of the busbar body and is formed by drawing toward the side where the flange is located, and the groove passes through the columnar protrusion.

[0019] In this way, the columnar protrusion in the middle can contact the cover of the battery, so that the cover is in a charged state, thereby preventing the battery from being electrochemically corroded during use.

[0020] A cylindrical battery, characterized by comprising the busbar as described above.

[0021] In summary, the utility model has the advantages of reasonable structural design, being able to avoid diaphragm melting, and being beneficial to ensuring battery quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the cross-sectional structure of a grooved cylindrical battery.

[0023] Figure 2 for Figure 1 The enlarged structural diagram is shown in the middle circle.

[0024] Figure 3 It is a schematic diagram of the front view structure of the busbar.

[0025] Figure 4 Schematic diagram of the overall structure of the busbar. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the embodiments.

[0027] When implementing: Figure 1 to Figure 4 As shown, a grooved cylindrical battery comprises a single-pass shell 11, the end plate of the single-pass shell 11 has a through hole arranged concentrically, and the through hole is insulated with a pole 12; a winding core 13 is arranged in the single-pass shell 11, one end of the winding core 13 is welded with a first busbar, and the other end is welded with a second busbar 14, the first busbar is welded to the pole 12, and the second busbar 14 comprises a circular busbar body 1, the middle part of the busbar body 1 has a concentrically arranged center hole 2, the edge of the busbar body 1 has a flange 3 folded toward one side, and a plurality of flanges 3 are evenly arranged along the circumference of the busbar body 1; the connection between the busbar body 1 and the flange 3 is drawn toward the direction of the flange 3 to form a boss 4, and the flange 3 is located on the edge of the boss 4. The flange 3 is attached to the inner wall of the shell and is welded to the shell by wall welding.

[0028] The edge of the boss 4 has a connection portion 5 extending radially outward from the busbar body 1, and the flange 3 is connected to the edge of the connection portion 5. In this way, the flange can be radially away from the edge of the busbar body, and the welding position can be away from the winding core, reducing the risk of diaphragm melting. The boss 4 is arranged in a fan shape extending radially toward the middle of the busbar body 1, and has a through hole arranged through it. At least two through holes are arranged radially along the busbar body 1, and the diameter of the through hole gradually decreases in the direction away from the flange 3.

[0029] The middle part of the busbar body 1 is concentrically provided with a columnar protrusion 8 formed by drawing toward the side where the flange 3 is located, and the other end of the shell is equipped with a cover plate 15 through a rolling groove structure. In order to ensure a good seal between the cover plate 15 and the shell, a sealing ring 16 is provided between the cover plate 15 and the shell, and the columnar protrusion 8 abuts against the cover plate 15. In this way, the columnar protrusion 8 can contact the cover plate 15, so that the cover plate is in a charged state when the battery is working, and the cover plate is prevented from being electrochemically corroded during use.

[0030] The middle part of the busbar body 1 has a groove 7 extending in the radial direction, one end of which is connected to the center hole 2 and passes through the columnar protrusion 8. The middle part of the busbar body is divided into multiple petals by the grooves. When the busbar is welded to the shell, the busbar is subjected to the inward force of the shell, and the multiple petals can release part of the pressure.

[0031] In this embodiment, the thickness of the connecting portion 5 is less than the thickness of the busbar body 1, and has a through-set weakening hole 6, and a plurality of the weakening holes 6 are arranged at intervals along the length direction of the connecting portion 5. In this way, the strength of the connecting portion can be reduced, the flexibility of the connecting portion can be increased, and the flange can be better adapted to the inner wall of the shell, so that the flange and the shell are in closer contact, preventing cold welding and improving the reliability of welding. At the same time, during the rolling groove sealing process, the external force is applied to the busbar, and the thinner connecting portion on the boss can be bent, thereby reducing the force applied by the busbar to the pole group and preventing the pole group from being compressed and deformed.

[0032] In the present embodiment, since the boss is formed by drawing the busbar body, a gap will be formed between the boss and the core after the busbar body is welded to the core. When the flange is welded to the shell wall, the temperature rises suddenly, and the heat is conducted to the shell and the flange. Due to the existence of the gap, the heat cannot be directly conducted to the diaphragm, thereby avoiding the diaphragm from melting due to excessive temperature, which is beneficial to ensuring the quality of the battery.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A busbar, comprising a circular busbar body (1), wherein the middle of the busbar body (1) has a concentrically arranged central hole (2), characterized in that: The edge of the busbar body (1) has a flange (3) folded toward one side, and a plurality of flanges (3) are evenly distributed along the circumference of the busbar body (1); the connection between the busbar body (1) and the flange (3) is drawn in the direction of the flange (3) to form a boss (4), and the flange (3) is located on the edge of the boss (4).

2. The busbar according to claim 1, wherein: The edge of the boss (4) has a connecting portion (5) extending radially outwardly along the busbar body (1), and the flange (3) is connected to the edge of the connecting portion (5).

3. The busbar according to claim 2, wherein: The connecting portion (5) is provided with a through-going weakening hole (6), and a plurality of the weakening holes (6) are arranged at intervals along the length direction of the connecting portion (5).

4. The busbar according to claim 2, wherein: The thickness of the connecting portion (5) is smaller than the thickness of the busbar body (1).

5. The busbar according to claim 1, wherein: The boss (4) extends radially toward the middle of the busbar body (1) and is arranged in a fan shape.

6. The busbar according to claim 5, wherein: The boss (4) has a through hole extending therethrough.

7. The busbar according to claim 6, wherein: At least two through holes are arranged along the radial direction of the busbar body (1), and the diameters of the through holes gradually decrease in a direction away from the flange (3).

8. The busbar according to claim 1, wherein: The middle part of the busbar body (1) has a groove (7) extending in the radial direction, one end of the groove (7) is connected to the central hole (2); a plurality of grooves (7) are evenly distributed along the circumference of the busbar body (1).

9. The busbar according to claim 8, wherein: A columnar protrusion (8) is concentrically arranged in the middle of the busbar body (1) and is formed by drawing towards the side where the flange (3) is located, and the cut groove (7) passes through the columnar protrusion (8).

10. A cylindrical battery, characterized in that: The invention comprises the bus bar as claimed in any one of claims 1 to 9.

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