Cylindrical battery roll core structure

Abstract

The utility model relates to the technical field of batteries, in particular to a cylindrical battery roll core structure, which comprises a roll core piece and a tab, the tab is connected to the axial end of the roll core piece, an indentation groove is arranged on the tab, the indentation groove extends along the direction perpendicular to the axis of the roll core piece, and the indentation groove extends along the direction perpendicular to the axis of the roll core piece. The plurality of indentation grooves are arranged along the axial direction of the core rolling piece; the indentation grooves extend in the direction perpendicular to the axis of the core rolling piece, namely, the indentation grooves extend in the length direction of the tabs, so that the indentation processing mechanism compresses and processes the tabs into the indentation grooves; the plurality of indentation grooves are arranged along the axial direction of the core rolling piece, and the arrangement of the indentation grooves enables the tabs at the end parts of the core rolling piece in the axial direction to be bent from the creases more easily when the tabs are kneaded, so that the required kneading force is smaller, and metal scraps generated during kneading are smaller; therefore, the welding stress between the tabs and the positive pole confluence plate and the negative pole confluence plate is smaller.

Description

Technical Field

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

[0002] With the development of the industry, the application scenarios of lithium-ion batteries are becoming more and more extensive, and the application fields are becoming more and more complex. During the process of flattening the tabs of the cylindrical battery core of the existing lithium-ion battery, since the foil body has a certain degree of anti-deformation force, a large flattening force is required when flattening the tabs of the cylindrical battery core, which increases the risk of metal debris; after the reflux plate and the tab are welded, since the foil body has a certain degree of anti-deformation force, the welding stress between the reflux plate and the tab is large, and there is a risk of cracking. Utility Model Content

[0003] The technical problem to be solved by the utility model is that a large flattening force is required to flatten the tabs of the existing cylindrical battery roll core, which increases the risk of metal debris generation, and the welding stress between the tabs and the reflow plate is large, which poses a risk of cracking.

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

[0005] A cylindrical battery core structure includes a core and a pole ear, wherein the pole ear is connected to the axial end of the core, and an indentation groove is provided on the pole ear. The indentation groove extends in a direction perpendicular to the axis of the core, and a plurality of the indentation grooves are arranged in the axial direction of the core.

[0006] The cylindrical battery core structure provided by the utility model has the following beneficial effects compared with the prior art, but is not limited to:

[0007] A certain number of indentation grooves are processed on the pole ear by an indentation processing mechanism, and the indentation grooves extend in a direction perpendicular to the axis of the winding core, that is, the indentation grooves extend along the length direction of the pole ear, so as to facilitate the indentation processing mechanism to compress and process them into indentation grooves; multiple indentation grooves are arranged along the axial direction of the winding core, and the setting of the indentation grooves makes it easier for the pole ear at the axial end of the winding core to bend from the fold when flattening, and the required flattening force is smaller, and the metal debris generated during flattening is smaller, and the pole ear with the indentation groove has a smaller rebound force after flattening, so that the welding stress between the pole ear and the positive bus plate and the negative bus plate is smaller.

[0008] Preferably, the cross-section of the indentation groove is a symmetrical "V" shape.

[0009] Preferably, the distance between adjacent folds in the "V"-shaped cross section of the indentation groove is 1 mm-3 mm.

[0010] Preferably, the winding core member comprises a first separator, a second separator, a positive electrode sheet, a negative electrode sheet and a core shaft, and the positive electrode sheet, the first separator, the negative electrode sheet and the second separator are sequentially stacked and wound on the core shaft to form the winding core member;

[0011] The electrode tabs include a positive electrode tab and a negative electrode tab, wherein the positive electrode tab and the negative electrode tab are connected to the positive electrode sheet and the negative electrode sheet respectively and are located at two ends of the winding core respectively, and a plurality of the indentation grooves are respectively arranged on the positive electrode tab and the negative electrode tab.

[0012] Preferably, the depth of the indentation groove on the positive electrode tab is less than or equal to the thickness of the positive electrode sheet; the depth of the indentation groove on the negative electrode tab is less than or equal to the thickness of the negative electrode sheet.

[0013] Preferably, the portion of the foil layer of the positive electrode sheet that protrudes relative to the coating layer is matched as the positive electrode tab, and the portion of the foil layer of the negative electrode sheet that protrudes relative to the coating layer is matched as the negative electrode tab.

[0014] Preferably, the positive electrode tab further comprises a positive electrode spacer located on the side of the plurality of indentation grooves close to the positive electrode sheet, and the negative electrode tab further comprises a negative electrode spacer located on the side of the plurality of indentation grooves close to the negative electrode sheet; the axial ends of the first diaphragm extend to overlap with the positive electrode spacer and the negative electrode spacer respectively;

[0015] The portion of the positive electrode tab between the first indentation groove close to the positive electrode sheet and the end of the first diaphragm is configured as a first thermal insulation zone, and the portion of the negative electrode tab between the first indentation groove close to the negative electrode sheet and the end of the first diaphragm is also configured as a first thermal insulation zone, and the width range of the first thermal insulation zone is 1mm-3mm.

[0016] Preferably, the axial ends of the second diaphragm extend to overlap with the positive electrode spacing area and the negative electrode spacing area respectively;

[0017] The portion of the positive electrode tab between the first indentation groove close to the positive electrode sheet and the end of the second diaphragm is configured as a second thermal insulation zone, and the portion of the negative electrode tab between the first indentation groove close to the negative electrode sheet and the end of the second diaphragm is also configured as a second thermal insulation zone, and the width range of the second thermal insulation zone is 1mm-3mm.

[0018] Preferably, the cylindrical battery core structure also includes a positive busbar, a positive electrode cover and a positive electrode column, the positive busbar is connected to the positive electrode ear, the positive electrode cover is installed at the end of the positive busbar, and the positive electrode column passes through the positive electrode cover and is connected to the positive busbar.

[0019] Preferably, the cylindrical battery core structure also includes a negative busbar, a negative electrode cover and a negative electrode column, the negative busbar is connected to the negative electrode ear, the negative electrode cover is installed at the end of the negative busbar, and the negative electrode column passes through the negative electrode cover and is connected to the negative busbar. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 The overall structure of the cylindrical battery core structure of the utility model embodiment is shown in FIG. Figure 1 ;

[0021] Figure 2 The overall structure of the cylindrical battery core structure of the utility model embodiment is shown in FIG. Figure 2 ;

[0022] Figure 3 for Figure 2 A schematic diagram of the enlarged structure at A in the middle;

[0023] Figure 4 It is a partial structural schematic diagram of a cylindrical battery roll core structure of an embodiment of the utility model;

[0024] Figure 5 The overall structure of the cylindrical battery core structure of the utility model embodiment is shown in FIG. Figure 3 .

[0025] Description of reference numerals:

[0026] 1 winding core, 11 first diaphragm, 12 second diaphragm, 13 positive electrode sheet, 14 negative electrode sheet, 2 positive electrode tab, 20 positive electrode spacing area, 200 first thermal insulation area, 3 negative electrode tab, 4 indentation groove, 5 positive electrode busbar, 6 positive electrode cover, 7 positive electrode column. DETAILED DESCRIPTION

[0027] The following is a further detailed description of the implementation of the present application in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present application but cannot be used to limit the scope of the present application.

[0028] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, and are 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 direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present invention.

[0029] It should be noted that, in the coordinate system XYZ provided in this document, the positive direction of the X-axis represents the right, the reverse direction of the X-axis represents the left, the positive direction of the Y-axis represents the front, the reverse direction of the Y-axis represents the back, the positive direction of the Z-axis represents the top, and the reverse direction of the Z-axis represents the bottom; the meanings of the Z-axis, X-axis, and Y-axis are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0030] See also Figure 1-Figure 2 The utility model provides a cylindrical battery core structure, including a core member 1 and a pole ear, wherein the pole ear is connected to the axial end of the core member 1, and an indentation groove 4 is provided on the pole ear. The indentation groove 4 extends in a direction perpendicular to the axis of the core member 1, and a plurality of the indentation grooves 4 are arranged along the axial direction of the core member 1.

[0031] In this embodiment, a certain number of indentation grooves 4 are processed on the pole ear by an indentation processing mechanism, and the indentation grooves 4 extend in a direction perpendicular to the axis of the winding core member 1, that is, the indentation grooves 4 extend along the length direction of the pole ear, so as to facilitate the indentation processing mechanism to compress and process them into the indentation grooves 4; a plurality of the indentation grooves 4 are arranged along the axial direction of the winding core member 1, and the setting of the indentation grooves 4 makes it easier for the pole ear at the axial end of the winding core member 1 to bend from the fold when flattening, and the required flattening force is smaller, and the metal debris generated during flattening is smaller, and the pole ear with the indentation grooves 4 has a smaller rebound force after flattening, so that the welding stress between the pole ear and the positive bus plate 5 and the negative bus plate is smaller.

[0032] Preferably, if Figure 2-Figure 4 As shown, the cross-sectional shape of the indentation groove 4 is a symmetrical "V" shape. The vertex of the "V" shape is the indentation, and a plurality of the indentation grooves 4 are connected in sequence to form a sawtooth shape.

[0033] In this embodiment, the cross-sectional shape of the indentation groove 4 is convenient for the processing by the indentation processing mechanism on the one hand, and is conducive to making the tab easier to wind on the other hand.

[0034] Preferably, if Figure 4 As shown, the distance between adjacent folds in the "V"-shaped section of the indentation groove 4 is 1mm-5mm. The "V" shape includes two lines and three endpoints, each endpoint represents a fold, and the length of each line can also be called "the distance between adjacent folds".

[0035] Specifically, the indentation groove 4 includes a first surface and a second surface, the first surface and the second surface are connected in a symmetrical "V" shape, and the distance between adjacent folds in the "V"-shaped section is 1mm-5mm, that is, the width range of the first surface or the second surface is 1mm-5mm.

[0036] In this embodiment, the smaller the length of a line in the "V"-shaped cross-section of the indentation groove 4, the smaller the indentation groove 4 is, the smaller the required flattening force is, the smaller the metal debris generated during flattening is, and the rebound force of the pole ear with the indentation groove 4 after flattening is smaller.

[0037] Preferably, the winding core 1 comprises a first separator 11, a second separator 12, a positive electrode sheet 13, a negative electrode sheet 14 and a core shaft, and the positive electrode sheet 13, the first separator 11, the negative electrode sheet 14 and the second separator 12 are sequentially stacked and wound on the core shaft to form the winding core 1.

[0038] The tabs include a positive tab 2 and a negative tab 3, wherein the positive tab 2 and the negative tab 3 are connected to the positive electrode sheet 13 and the negative electrode sheet 14 respectively, and are located at both ends of the winding core 1 respectively, and a plurality of indentation grooves 4 are respectively provided on the positive tab 2 and the negative tab 3.

[0039] Preferably, the depth of the indentation groove 4 on the positive electrode tab 2 is less than or equal to the thickness of the positive electrode sheet 13; the depth of the indentation groove 4 on the negative electrode tab 3 is less than or equal to the thickness of the negative electrode sheet 14. The depth of the indentation groove 4 is the distance from the midpoint to the vertex of the line connecting the two ends in the "V"-shaped cross section of the indentation groove 4.

[0040] In this embodiment, the depth of the indentation groove 4 does not exceed the thickness of the pole piece, which is conducive to making the positive electrode tab 2 or the negative electrode tab 3 easier to be wound with the pole piece.

[0041] Preferably, the portion of the foil layer of the positive electrode sheet 13 extending relative to the coating layer is matched as the positive electrode tab 2 , and the portion of the foil layer of the negative electrode sheet 14 extending relative to the coating layer is matched as the negative electrode tab 3 .

[0042] Specifically, the positive electrode sheet 13 and the negative electrode sheet 14 both refer to a structure consisting of a foil layer and a coating layer; the positive electrode tab and the negative electrode tab can be formed by the foil layer of the positive electrode sheet 13 and the negative electrode sheet 14 respectively (that is, the part of the foil layer without a coating layer).

[0043] In this embodiment, the positive electrode sheet 13, the first separator 11, the negative electrode sheet 14, the second separator 12 and the core shaft are wound to form the winding core 1, and the positive electrode tab 2 and the negative electrode tab 3 are respectively connected to the starting end of the positive electrode sheet 13 and the starting end of the negative electrode sheet 14, so that the positive electrode tab 2 and the negative electrode tab 3 are respectively connected to the two ends of the winding core 1.

[0044] Preferably, the positive electrode tab 2 also has a positive electrode spacer 20 located on the side of the multiple indentation grooves 4 close to the positive electrode sheet 13, and the negative electrode tab 3 also has a negative electrode spacer located on the side of the multiple indentation grooves 4 close to the negative electrode sheet 14; the axial ends of the first diaphragm 11 extend to overlap with the positive electrode spacer 20 and the negative electrode spacer respectively.

[0045] The portion of the positive electrode tab between the first indentation groove 4 close to the positive electrode sheet 13 and the end of the first diaphragm 11 is configured as a first thermal insulation zone 200, and the portion of the negative electrode tab between the first indentation groove 4 close to the negative electrode sheet 14 and the end of the first diaphragm 11 is also configured as a first thermal insulation zone 200, and the width range of the first thermal insulation zone 200 is 1mm-3mm.

[0046] Specifically, the positive electrode spacing area 20 is the area between the connection between the positive electrode tab 2 and the positive electrode sheet 13 and the first indentation groove 4 close to the positive electrode sheet 13 .

[0047] Preferably, two axial ends of the second separator 12 extend to overlap with the positive electrode spacing region 20 and the negative electrode spacing region, respectively.

[0048] The portion of the positive electrode tab between the first indentation groove 4 close to the positive electrode sheet 13 and the end of the second diaphragm 12 is configured as a second thermal insulation zone, and the portion of the negative electrode tab between the first indentation groove 4 close to the negative electrode sheet 14 and the end of the second diaphragm 12 is also configured as a second thermal insulation zone, and the width range of the second thermal insulation zone is 1mm-3mm.

[0049] Specifically, the negative electrode spacing area is the area between the connection between the negative electrode tab 3 and the negative electrode sheet 14 and the first indentation groove 4 close to the negative electrode sheet 14; the first diaphragm 11 and the second diaphragm 12 have the same size.

[0050] In this embodiment, the provision of the first thermal insulation area 200 and the second thermal insulation area is beneficial to preventing the first diaphragm 11 and the second diaphragm 12 from being damaged by laser in a subsequent welding process.

[0051] Preferably, if Figure 5 As shown, the cylindrical battery core structure also includes a positive busbar 5, a positive electrode cover 6 and a positive electrode column 7, the positive busbar 5 is connected to the positive electrode ear 2, the positive electrode cover 6 is installed on the end of the positive busbar 5, and the positive electrode column 7 passes through the positive electrode cover 6 and is connected to the positive busbar 5.

[0052] Specifically, the positive electrode busbar 5 is welded to the flattened positive electrode tab 2 .

[0053] Preferably, the cylindrical battery core structure also includes a negative busbar, a negative electrode cover and a negative electrode column, the negative busbar is connected to the negative electrode ear 3, the negative electrode cover is installed at the end of the negative busbar, and the negative electrode column passes through the negative electrode cover and is connected to the negative busbar.

[0054] Specifically, the negative electrode busbar is welded to the flattened negative electrode tab 3 .

[0055] Although the utility model is disclosed as above, the protection scope of the utility model is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the utility model, and these changes and modifications will fall within the protection scope of the utility model.

Claims

1. A cylindrical battery core structure, characterized in that: The invention comprises a winding core (1) and a pole ear, wherein the pole ear is connected to the axial end of the winding core (1), and an indentation groove (4) is provided on the pole ear, wherein the indentation groove (4) extends in a direction perpendicular to the axis of the winding core (1), and a plurality of the indentation grooves (4) are arranged in the axial direction of the winding core (1).

2. The cylindrical battery core structure according to claim 1, characterized in that: The cross-sectional shape of the indentation groove (4) is a symmetrical "V" shape.

3. The cylindrical battery core structure according to claim 2, characterized in that: The distance between adjacent folds in the "V"-shaped cross section of the indentation groove (4) is 1 mm to 5 mm.

4. The cylindrical battery core structure according to claim 2, characterized in that: The winding core (1) comprises a first separator (11), a second separator (12), a positive electrode sheet (13), a negative electrode sheet (14) and a core shaft, wherein the positive electrode sheet (13), the first separator (11), the negative electrode sheet (14) and the second separator (12) are sequentially stacked and wound on the core shaft to form the winding core (1); The electrode tabs include a positive electrode tab (2) and a negative electrode tab (3), wherein the positive electrode tab (2) and the negative electrode tab (3) are respectively connected to the positive electrode sheet (13) and the negative electrode sheet (14), and are respectively located at two ends of the winding core (1), and a plurality of the indentation grooves (4) are respectively provided on the positive electrode tab (2) and the negative electrode tab (3).

5. The cylindrical battery core structure according to claim 4, characterized in that: The depth of the indentation groove (4) on the positive electrode tab (2) is less than or equal to the thickness of the positive electrode sheet (13); The depth of the indentation groove (4) on the negative electrode tab (3) is less than or equal to the thickness of the negative electrode sheet (14).

6. The cylindrical battery core structure according to claim 4, characterized in that: The portion of the foil layer of the positive electrode sheet (13) that protrudes relative to the coating layer is matched to form the positive electrode tab (2), and the portion of the foil layer of the negative electrode sheet (14) that protrudes relative to the coating layer is matched to form the negative electrode tab (3).

7. The cylindrical battery core structure according to claim 4, characterized in that: The positive electrode tab (2) further comprises a positive electrode spacer (20) located on the side of the plurality of indentation grooves (4) close to the positive electrode sheet (13), and the negative electrode tab (3) further comprises a negative electrode spacer located on the side of the plurality of indentation grooves (4) close to the negative electrode sheet (14); the axial ends of the first diaphragm (11) respectively extend to overlap with the positive electrode spacer (20) and the negative electrode spacer; The portion of the positive electrode tab (2) between the first indentation groove (4) close to the positive electrode sheet (13) and the end of the first diaphragm (11) is configured as a first thermal insulation zone (200), and the portion of the negative electrode tab (3) between the first indentation groove (4) close to the negative electrode sheet (14) and the end of the first diaphragm (11) is also configured as a first thermal insulation zone (200), and the width of the first thermal insulation zone (200) ranges from 1 mm to 3 mm.

8. The cylindrical battery core structure according to claim 7, characterized in that: The axial ends of the second diaphragm (12) respectively extend to overlap with the positive electrode spacing region (20) and the negative electrode spacing region; The portion of the positive electrode tab (2) between the first indentation groove (4) close to the positive electrode sheet (13) and the end of the second diaphragm (12) is configured as a second thermal insulation zone, and the portion of the negative electrode tab (3) between the first indentation groove (4) close to the negative electrode sheet (14) and the end of the second diaphragm (12) is also configured as a second thermal insulation zone, and the width range of the second thermal insulation zone is 1 mm-3 mm.

9. The cylindrical battery core structure according to claim 4, characterized in that: It also includes a positive busbar (5), a positive electrode cover (6) and a positive electrode column (7), wherein the positive busbar (5) is connected to the positive electrode ear (2), the positive electrode cover (6) is installed at the end of the positive busbar (5), and the positive electrode column (7) passes through the positive electrode cover (6) and is connected to the positive busbar (5).

10. The cylindrical battery core structure according to claim 4, characterized in that: It also includes a negative busbar, a negative pole cover and a negative pole column, wherein the negative busbar is connected to the negative pole ear (3), the negative pole cover is installed at the end of the negative busbar, and the negative pole column passes through the negative pole cover and is connected to the negative busbar.

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