Integrated busbar and cylindrical battery, and method for preparing busbar

Abstract

The application provides an integrated busbar, comprising a busbar bottom plate and a bending plate, the busbar bottom plate is arranged above a tab and is used for electrically connecting with the tab; the bending plate is integrally connected with the outer periphery of the busbar bottom plate, the bending plate is arranged to form a first bending area and a second bending area after being sequentially bent, the first bending area is directed to the radial inner side, and the second bending area is directed to the radial outer side; wherein, a sunken surface is formed at the tail end of the bending plate relative to the second bending area, a descending support rib surface is formed at the connection between the sunken surface and the second bending area, and the sunken surface is used for electrically connecting with the top cover of a battery. The application also provides a cylindrical battery and a method for preparing the busbar.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cylindrical batteries, in particular to the field of bus bars. BACKGROUND

[0002] The large cylindrical battery has the natural characteristics of product standardization and structural balance. However, the welding area strength of the bus bar in the current cylindrical battery and the pole or the shell is small, and there is a problem that the connection is easy to fall off, which will seriously affect the safety of the battery. In addition, most of the bus bars have complex structure and large size, which makes the cost of the battery higher. SUMMARY

[0003] An object of the present application is to provide an integrated bus bar which can significantly improve the safety of the battery.

[0004] To achieve the above-mentioned purpose, the integrated bus bar is arranged between the top cover and the tab of the battery, comprising a bus bar bottom sheet and a bending sheet, the bus bar bottom sheet is arranged above the tab for electrical connection with the tab; the bending sheet is integrally connected with the outer periphery of the bus bar bottom sheet, the bending sheet is arranged to form a first bending area and a second bending area after being bent in sequence, the first bending area is directed towards the radial inner side, and the second bending area is directed towards the radial outer side; wherein the tail end of the bending sheet forms a sunken surface relative to the second bending area, the connection between the sunken surface and the second bending area forms a descending support rib surface, and the sunken surface is used for electrical connection with the top cover of the battery.

[0005] In one or more embodiments, the bending position of the first bending area is located above the circumferential edge of the tab, and at least part of the sunken surface is arranged above the first bending area.

[0006] In one or more embodiments, the second bending area defines a bending cavity, and the height of the bending cavity is preferably greater than or equal to 0.5mm.

[0007] In one or more embodiments, bending notches are provided on both sides of the connection between the bending sheet and the bus bar bottom sheet as bending weakening areas.

[0008] In one or more embodiments, the outer periphery of the connection between the bus bar bottom sheet and the bending sheet is located radially inward of the outer periphery of the area where the bus bar bottom sheet is not connected with the bending sheet.

[0009] In one or more embodiments, the sunken surface is staggered with the first bending area.

[0010] In one or more embodiments, the top cover comprises a sunken groove for electrical connection with the sunken surface and the descending support rib surface.

[0011] Another object of the present application is to provide a cylindrical battery, comprising a shell, a core package, a tab, a top cover, and further comprising the above-mentioned integrated busbar for realizing the electrical conduction between the tab and the top cover.

[0012] Still another object of the present application is to provide a method for preparing a busbar for preparing the above-mentioned integrated busbar, comprising the following steps: S1. aligning the outer periphery of the busbar base with the outer periphery of the tab; S2. folding the bending sheet towards the radial inner side for the first time, so that the bending position of the first bending area is above the outer periphery of the tab; S3. continuing to pre-fold the bending sheet towards the radial outer side, stamping the tail end of the bending sheet to form a sunken surface and a descending support rib surface, and making the sunken surface not in contact with the shell of the battery; S4. pressing down the pre-folded part of the bending sheet with the descending support rib surface as the end, so that the part forms a second bending area.

[0013] In one or more embodiments, the top cover comprises a sunken groove which is in contact with the sunken surface, and in step S3, the position of the sunken surface formed after stamping the tail end of the bending sheet is located through the sunken groove.

[0014] In one or more embodiments, in step S4, the height of the bending cavity defined by the second bending area is determined first, and then the pre-folded part of the bending sheet is pressed down so that the part forms a second bending area. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above-mentioned and other features, properties, and advantages of the present application will become more apparent by describing the following embodiments in conjunction with the accompanying drawings and examples, in which:

[0016] Figure 1 is a schematic diagram of the components of a cylindrical battery;

[0017] Figure 2 is an oblique view of one embodiment of the integrated busbar;

[0018] Figure 3 is an elevated oblique view of one embodiment of the integrated busbar;

[0019] Figure 4 is a plan view of one embodiment of the integrated busbar;

[0020] Figure 5 is a sectional view of the F-F direction in Figure 4

[0021] Figure 6 is an oblique view of another embodiment of the integrated busbar;

[0022] Figure 7 is an elevated oblique view of another embodiment of the integrated busbar; ​

[0023] Figure 8 is a top view of another embodiment of the integrated busbar;

[0024] Figure 9 is Figure 8 is a sectional view in the G-G direction. DETAILED DESCRIPTION

[0025] The present application will be further described with reference to the accompanying drawings in which:

[0026] It should be noted that these and other accompanying drawings are merely illustrative and are not drawn to scale, and should not be used to limit the scope of the present application.

[0027] Figure 1 The structure of the cylindrical battery is shown, including the shell 14, the core package 13, the tab 11, the top cover 15, the pole 16, and the busbar 12 is arranged between the top cover 15 and the tab 11 to realize the electrical conduction between the tab 11 and the top cover 15.

[0028] The integrated busbar according to the present disclosure is shown in Figures 2 to 9 , which includes a busbar bottom sheet 121 and a bending sheet 120. The busbar bottom sheet 121 is arranged above the tab 11, and the bottom surface serves as a busbar surface 1210 to contact the tab 11 to realize the electrical connection with the tab 11. The busbar bottom sheet 121 can be a fan ring or a circular ring. When the busbar bottom sheet 121 is a circular ring, as shown in Figure 4 , the circumferential angle α of the busbar bottom sheet 121 is equal to 360°. The bending sheet 120 is integrally connected with the outer periphery of the busbar bottom sheet 121 and is used for folding in the vertical space.

[0029] The term "outer periphery" includes various distribution structures. For example, in some embodiments, the busbar bottom sheet 121 is a complete fan ring, and the bending sheet 120 is directly extended from the outer periphery of the fan ring; in other embodiments, the fan ring part of the busbar bottom sheet 121 forms a notch, and the bending sheet 120 is arranged on the outer periphery in the notch, as shown in Figure 3 ; in still other embodiments, the outer periphery B at the connection between the busbar bottom sheet 121 and the bending sheet 120 is located radially inward of the outer periphery A of the area where the busbar bottom sheet 121 is not connected with the bending sheet 120, as shown in Figure 7 , that is, the outer periphery at the connection between the busbar bottom sheet 121 and the bending sheet 120 is radially inwardly moved.

[0030] The bending piece 120 is configured to form a first bending area 122 and a second bending area 123 after being bent sequentially. The first bending area 122 faces radially inward, and the second bending area 123 faces radially outward. The term "radial" refers to the radial direction of the busbar substrate 121, and "radial inward" also refers to... Figures 2 to 9 The right side shown also refers to "radial outer side". Figures 2 to 9 The left side is shown.

[0031] The tail end of the bent piece 120 forms a sunken surface 124 relative to the second bending area 123, and the connection between the sunken surface 124 and the second bending area 123 forms a descending support rib surface 125.

[0032] The sunken surface 124 serves as a current-conducting surface for electrical connection with the battery top cover 15.

[0033] The descending support rib 125 is connected to the sunken surface 124 on one side and to the second bending area 123 on the other side. Due to the presence of the descending support rib 125, the bending piece 120 can ensure that the bending only occurs in the second bending area 123 when it is folded, and has no effect on the sunken surface 124, which serves as the confluence and conduction surface.

[0034] In some embodiments, the circumferential lengths of the sunken surface 124 and the descending support rib surface 125 are equal and greater than the circumferential lengths of the bending surfaces of the first bending region 122 and the second bending region 123, such as... Figure 4 As shown, this is done to increase the electrical contact area.

[0035] In addition, to further adapt to the design of the integrated busbar, in some preferred embodiments, the top cover 15 of the battery includes a recessed groove (not shown) for simultaneously achieving electrical connection with the recessed surface 124 and the descending support rib surface 125.

[0036] The bending position of the first bending zone 122 is located above the circumferential edge of the tab 11, such as... Figure 5 As shown, at least part of the sunken surface 124 is positioned above the first bending area 122. During the manufacturing of the busbar, the positions of the first bending area 122 and the sunken surface 124 can be preferentially determined, thereby allowing any errors or tolerances that may exist during battery assembly or processing to be absorbed by the second bending area 123. Specifically, the errors or tolerances can be adaptively adjusted by freely changing the position of the second bending area 123.

[0037] Preferably, the second bending area 123 further defines a bending cavity 126, the presence of the bending cavity 126 makes the second bending area 123 have a flexible feature. When the battery is subjected to extrusion impact force, the bending cavity 126 can absorb part of the external impact force, avoid the force being transmitted to the welding surface of the tab 11 and the busbar bottom sheet 121, so as to avoid the welding point from being shaken, vibrated or pulled off, thereby improving the safety of the battery.

[0038] The height H of the bending cavity 126 is preferably greater than or equal to 0.5 mm.

[0039] In some embodiments, the bending piece 120 is provided with a bending notch 125 on both sides of the connection with the busbar bottom sheet 121, which can be understood with reference to the bottom view shown in Figure 3 and Figure 7 The bending notch 125 is provided at the root of the first bending area 122 as a bending weakening area. The bending notch 125 shortens the length of the bending area, facilitates bending, and can also ensure that each folding of the bending piece 120 occurs at this position, thereby ensuring the stability of production.

[0040] Figures 6 to 9 The embodiment of the integrated busbar shown is different from the embodiment shown in Figures 2 to 5 in that the position of the bending piece 120 and the shape of the busbar bottom sheet 121 are different. As shown in Figure 7 and Figure 9 The outer periphery of the connection between the busbar bottom sheet 121 and the bending piece 120 is radially inwardly displaced, so that the sunken surface 124 is staggered with the first bending area 122 to form a gap W in the horizontal direction, which can prevent the bending piece 120 from being broken when folded.

[0041] At the same time, the busbar bottom sheet 121 has two busbar branch surfaces 1211 on the busbar surface 1210, which are located on both sides of the first bending area 122 and adjacent to the bending notches 125 of the first bending area 122. The presence of the busbar branch surface 1211 can increase the contact area between the busbar surface and the tab of the core package, thereby increasing the flow capacity.

[0042] In combination with the introduction of the above-mentioned integrated busbar structure, a method for preparing the busbar can also be understood.

[0043] The method comprises the following steps: S1. aligning the outer periphery of the busbar base plate 121 with the outer periphery of the tab 11; S2. folding the bending plate 120 towards the inner side in the first time to make the bending position of the first bending area 122 above the outer periphery of the tab 11; S3. continuing to pre-fold the bending plate 120 towards the inner side, making the tail end of the bending plate 120 towards the outer side, stamping the tail end of the bending plate 120 to form the sunken surface 124 and the descending support rib surface 125, and making the sunken surface 124 not contact with the shell 14 of the battery; S4. pressing down the pre-folded part of the bending plate 120 in step S3 with the descending support rib surface 125 as the end to make the folded part be flattened to form the second bending area 123.

[0044] When the top cover 15 comprises the sunken groove matched with the sunken surface 124, the position of the sunken surface formed by stamping the tail end of the bending plate in step S3 is positioned by the sunken groove.

[0045] In step S4, the height of the bending cavity 126 defined by the second bending area 123 can also be determined first, and then the pre-folded part of the bending plate is pressed down to make the bending position of the second bending area 123 be determined.

[0046] Through the above manufacturing method, the integrated busbar can better adapt to the installation of the battery tab and the top cover. Even if there is a dimensional error in the battery tab and the top cover, the part of the error can be absorbed by adjusting the bending position of the second bending area, avoiding interference between components during assembly, and improving the yield of battery manufacturing.

[0047] In combination with the above method and the busbar, it can also be understood that a cylindrical battery comprising the above integrated busbar has higher safety and higher preparation yield, significantly reducing the manufacturing cost.

[0048] It should be noted that the use of the words "first", "second", etc. to define parts only facilitates the differentiation of the corresponding parts, and the above words have no special meaning unless otherwise stated, and therefore cannot be understood as limiting the scope of protection of the present application.

[0049] In the description of the present application, it should be understood that the orientation words such as "front, back, up, down, left, right", "transverse, vertical, perpendicular, horizontal" and "top, bottom" and the like indicate the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and in the absence of the opposite description, these orientation words do not indicate and imply that the indicated device or element must have a specific orientation or be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application; the orientation words "inner, outer" refer to the inner and outer of the contour of each part itself.

[0050] Although the present application has been disclosed in its preferred embodiments with reference to the accompanying drawings, it is not intended to limit the present application thereto, and any person skilled in the art can make possible changes and modifications without departing from the spirit and scope of the present application. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application without departing from the technical solutions of the present application, all fall within the protection scope defined by the claims of the present application.

Claims

1. An integrated busbar, disposed between the top cover and the tab of the battery, characterized in that, include: A busbar base plate is disposed above the electrode tab for electrical connection with the electrode tab; The bending piece is integrally connected to the outer periphery of the busbar substrate. The bending piece is configured to form a first bending area and a second bending area after being bent in sequence. The first bending area is oriented radially inward, and the second bending area is oriented radially outward. Wherein, the tail end of the bent piece forms a sunken surface relative to the second bending area, and the connection between the sunken surface and the second bending area forms a descending support rib surface, and the sunken surface is used for electrical connection with the top cover of the battery; The bending position of the first bending area is located above the circumferential edge of the electrode tab, and at least part of the sunken surface is disposed above the first bending area.

2. The integrated busbar as described in claim 1, characterized in that, The second bending area defines a bending cavity, the height of which is greater than or equal to 0.5 mm.

3. The integrated busbar as described in claim 1, characterized in that, The bending plate and the busbar substrate are provided with bending notches on both sides as bending weakening zones.

4. The integrated busbar as described in claim 1, characterized in that, The outer periphery of the connection between the busbar and the bending piece is located radially inside the outer periphery of the area where the busbar is not connected to the bending piece.

5. The integrated busbar as described in claim 4, characterized in that, The sunken surface is staggered with the first bending area.

6. The integrated busbar as described in claim 1, characterized in that, The top cover includes a recessed groove for electrical connection with the recessed surface and the descending support rib surface.

7. A cylindrical battery, comprising a casing, a core pack, tabs, and a top cover, characterized in that, It also includes an integrated busbar as described in any one of claims 1-6, the integrated busbar being used to realize electrical conduction between the tab and the top cover.

8. A method for preparing a busbar, characterized in that, The method for preparing the integrated busbar as described in any one of claims 1-6 comprises the following steps: S1. Align the outer periphery of the busbar film with the outer periphery of the tab; S2. Fold the bending piece radially inward for the first time, so that the bending position of the first bending area is above the outer periphery of the electrode tab; S3. Continue to pre-fold the bent piece radially outward, and press the tail end of the bent piece to form a sunken surface and a descending support rib surface, so that the sunken surface does not contact the battery casing. S4. Using the descending support rib surface as the end, press down the pre-folded part of the bending piece to form the second bending zone.

9. The method for preparing a busbar as described in claim 8, characterized in that, The top cover includes a recessed groove that fits into the recessed surface. In step S3, the recessed groove is used to position the recessed surface formed after the tail end of the stamped and bent piece.

10. The method for preparing a busbar as described in claim 8, characterized in that, In step S4, the height of the bending cavity defined by the second bending zone is first determined, and then the pre-folded part of the bending piece is pressed down so that the part forms the second bending zone.

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