Welding structure of multi-tab roll core and convergence disc

Abstract

The utility model discloses a welding structure of a multi-tab roll core and a confluence disc, which is characterized in that the welding structure comprises a roll core and the confluence disc, the two ends of the roll core are provided with multi-tabs and are provided with welding areas which are uniformly distributed along the circumferential direction of the roll core, and the tabs in the welding areas are connected by adopting ultrasonic welding; the confluence disc is provided with a confluence area corresponding to the welding area, and the confluence area corresponds to the welding area and is connected with the welding area in a welding mode. The utility model has the advantages that the hot melting risk of the battery diaphragm can be reduced, the safety of the battery cell is improved, the internal resistance of the battery cell is reduced, and the welding yield of the confluence plate is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a welding structure of a multi-electrode winding core and a busbar. 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. The internal structure of large cylindrical batteries mainly includes a winding core and a busbar welded at both ends of the winding core. There are two main existing busbar welding methods. One is to use laser cutting to flatten the multi-pole ears and directly weld them to the busbar, but the busbar welding is easy to melt the diaphragm, the process yield is low, and the risk of short circuit is high; secondly, the flatness of the welding surface is difficult to control, and the ear has a rebound effect after flattening; and the cut and stacked ears are in physical contact after flattening, which is easy to generate impedance. The other is to flatten the full ear and directly weld it to the busbar, but the length of the uncoated foil of the flattened battery cell is long, the ear length is long, and the capacity is low; there are too many metal debris in the flattening process of the flattened battery cell, and there is a risk of self-discharge; the flattened ear is in physical contact, which is easy to generate impedance; 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 welding structure of a multi-electrode winding core and a busbar that can reduce the risk of hot melting of the battery separator, improve the safety of the battery cell, reduce the internal resistance of the battery cell, and improve the welding yield of the busbar.

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

[0005] A welding structure of a multi-pole winding core and a busbar, characterized in that it includes a winding core and a busbar, wherein the two ends of the winding core are multi-pole ears and have welding areas evenly distributed along the circumference of the winding core, and the pole ears in the welding areas are connected by ultrasonic welding; the busbar has a busbar area arranged corresponding to the welding area, and the busbar area corresponds to the welding area and is welded together.

[0006] In the above structure, ultrasonic welding is used to connect the pole ears together, which can achieve the effect of flattening the battery cell to reduce the gap between the pole ears and make the pole ears harder; thereby, the flatness of the welding surface can be better controlled to avoid the rebound of the pole ears, thereby reducing the risk of hot melting of the battery diaphragm, improving the safety of the battery cell and the welding yield of the busbar; in addition, ultrasonic welding is used to connect the pole ears to reduce impedance and reduce the internal resistance of the battery cell.

[0007] Furthermore, the bus area is integrally recessed toward the winding core and is protruded relative to the bus plate.

[0008] In this way, the convergence area and the welding area can be more closely fitted, making the welding process window larger.

[0009] Furthermore, the thickness of the busbar area is smaller than the thickness of the busbar plate.

[0010] In this way, the confluence area can have better deformation ability, so that it can better fit the welding area, facilitate laser welding, and help improve the welding yield.

[0011] Furthermore, the welding area and the confluence area are both fan-shaped.

[0012] Furthermore, the busbar area has weakening holes arranged in strips along the edge, and the weakening holes penetrate the busbar plate along the thickness direction.

[0013] In this way, the strength between the busbar area and the busbar plate body can be reduced by weakening the hole, so that the busbar area can be better deformed to fit the welding area, which is beneficial to improving the welding yield.

[0014] Furthermore, a plurality of the weakening holes are arranged at intervals along the edge of the confluence area.

[0015] Furthermore, the confluence plate has a lower liquid hole which is arranged through the thickness thereof, and the lower liquid hole is located between two adjacent confluence areas.

[0016] Furthermore, the lower liquid hole extends into a strip shape along the radial direction of the confluence plate.

[0017] Furthermore, the middle portion of the busbar has a concentrically arranged center hole.

[0018] In summary, the utility model has the advantages of reducing the risk of thermal melting of battery separators, improving the safety of battery cells, reducing the internal resistance of battery cells, and improving the welding yield of busbars. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the decomposition structure of Example 1.

[0020] Figure 2 This is a schematic diagram of the winding core structure of Example 2.

[0021] Figure 3 This is a schematic diagram of the busbar structure of Example 2. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the embodiments.

[0023] Example 1: Figure 1As shown, a welding structure of a multi-electrode winding core and a busbar includes a winding core 1 and a busbar 2. The winding core 1 has multiple poles at both ends and has welding areas 3 evenly distributed along the circumference of the winding core. The poles of the welding areas 3 are connected by ultrasonic welding. The busbar 2 has a busbar area 4 corresponding to the welding area 3. The busbar area 4 corresponds to and is welded to the welding area 3. The busbar 2 has a concentrically arranged center hole 7 in the middle. The busbar 2 is recessed as a whole toward the direction of the winding core 1 and is protruding relative to the busbar 2. The thickness of the busbar 4 is less than that of the busbar 2. In this embodiment, the welding area 3 and the busbar 4 are both strips extending radially.

[0024] In the above structure, ultrasonic welding is used to connect the pole ears together, which can achieve the effect of flattening the battery cell to reduce the gap between the pole ears and make the pole ears harder; thereby, the flatness of the welding surface can be better controlled to avoid the rebound of the pole ears, thereby reducing the risk of hot melting of the battery diaphragm, improving the safety of the battery cell and the welding yield of the busbar; in addition, ultrasonic welding is used to connect the pole ears to reduce impedance and reduce the internal resistance of the battery cell.

[0025] Example 2: Figure 2 and Figure 3 As shown, a welding structure of a multi-pole lug winding core and a busbar includes a winding core 1 and a busbar 2. The winding core 1 has multi-pole lugs at both ends and has welding areas 3 evenly distributed along the circumference of the winding core. The pole lugs in the welding areas 3 are connected by ultrasonic welding. The busbar 2 has a busbar area 4 corresponding to the welding area 3. The busbar area 4 corresponds to the welding area 3 and is welded to the busbar 3. The middle of the busbar 2 has a concentrically arranged center hole 7. The busbar 4 is overall recessed toward the direction of the winding core 1 and is protruding relative to the busbar 2. The thickness of the busbar 4 is less than the thickness of the busbar 2. In this embodiment, Figure 2 As shown, the welding area 3 and the busbar area 4 are both fan-shaped, and the busbar area 4 has a weakening hole 5 arranged in a strip shape along the edge, and the weakening hole 5 penetrates the busbar plate 2 along the thickness direction, and a plurality of the weakening holes 5 are arranged at intervals along the edge of the busbar area 4. In this way, the strength between the busbar area and the busbar plate body can be reduced by the weakening holes, so that the busbar area can be better deformed to fit the welding area, which is conducive to improving the welding yield.

[0026] In addition, the confluence plate 2 has a lower liquid hole 6 that is arranged through the thickness, and the lower liquid hole 6 is located between two adjacent confluence areas 4. The lower liquid hole 6 extends into a strip shape along the radial direction of the confluence plate 2. In this way, the electrolyte can flow into the winding core faster through the lower liquid hole.

[0027] 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 welding structure of a multi-electrode winding core and a busbar, characterized in that: The invention comprises a winding core (1) and a busbar (2), wherein the winding core (1) has multiple pole ears at both ends and has welding areas (3) evenly distributed along the circumference of the winding core, and the pole ears of the welding areas (3) are connected by ultrasonic welding; and the busbar (2) has a busbar area (4) arranged corresponding to the welding area (3), and the busbar area (4) corresponds to the welding area (3) and is connected by welding.

2. The welding structure of the multi-electrode winding core and the busbar according to claim 1, characterized in that: The confluence area (4) is integrally recessed in the direction of the winding core (1), and is arranged to protrude relative to the confluence plate (2).

3. The welding structure of the multi-electrode winding core and the busbar according to claim 2, characterized in that: The thickness of the busbar area (4) is smaller than the thickness of the busbar plate (2).

4. The welding structure of the multi-electrode winding core and the busbar as claimed in claim 2, characterized in that: The welding area (3) and the confluence area (4) are both fan-shaped.

5. The welding structure of the multi-electrode winding core and the busbar according to claim 2, characterized in that: The busbar area (4) is provided with a weakening hole (5) arranged in a strip shape along the edge, and the weakening hole (5) penetrates the busbar plate (2) along the thickness direction.

6. The welding structure of the multi-electrode winding core and the busbar according to claim 5, characterized in that: A plurality of weakening holes (5) are arranged at intervals along the edge of the confluence area (4).

7. The welding structure of a multi-electrode winding core and a busbar as claimed in claim 2, characterized in that: The confluence plate (2) is provided with a lower liquid hole (6) which is arranged through the thickness thereof, and the lower liquid hole (6) is located between two adjacent confluence areas (4).

8. The welding structure of a multi-electrode winding core and a busbar as claimed in claim 7, characterized in that: The lower liquid hole (6) extends in a strip shape along the radial direction of the collecting plate (2).

9. The welding structure of a multi-electrode winding core and a busbar as claimed in claim 1, characterized in that: The middle of the busbar (2) has a concentrically arranged central hole (7).

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